Document KMqn4531z0LN292qJo8EgO20

BFG TECHNICAL DOCUMENT 1981 MINUTES VINYL CHLORIDE SAFETY ASSOCIATION MEETING J.F. MALONE/R.C. KAMINSKI N.R. AQUINO/F.E. KRAUSE R.A. RRUEGER/R.E. PASQUALl/R.A. TRAFAS J.M. MADIGAN/G.F. LEFEBVRE/H.R. CALSING TTre.-MARTIMELLI/il. WA'UTEMATE --^^ W.E. BRODINE/H.H. BORSVOLD/G.H. METZGER E.L. BEELER AND STAFF C.J. NOSAL AND STAFF W.E. HORTON AND STAFF J. CORONA AND STAFF R.M. SANDFRY AND STAFF R.D. MOORE AND STAFF L.V. GOODE AND STAFF C.L. WOODS AND STAFF R.K. SCHLATZER/J.A. GLASS C. E. FLEMING AND STAFF D. A. BROOKS AND STAFF NOTE: The distribution list has been reduced. Please share copies of this report with all. interested parties. Ron Kaminski. Glen 0. Schaaf *?GC 23255 CONTENTS I. Meeting Notes II. Attachments 1. PVC Dust Studies 2. Operator Training Survey 3. Small Reactor Safety Survey 4. Computer Control Survey 5. U.S, Patent 4004880 (Hulls method to vent runaway reactions) 6. VCM Tank Car Derailment 7. Regulatory Update 8. Speech Highlights -S *w NOC 23256 VINYL CHLORIDE SAFETY ASSOCIATION MINUTES 1981 True Confessions; (1) Process Sever Explosion - Jack McCauleyr Conoco - An explosion occurred in the sewer system at the Lake Charles vinyl chloride plant. Vapors from the waste system were vented to the oxychlorination unit- A tank which was located aboveground contained a waste steam which was pumped to a belowground tank. The top drum blew off the aboveground tank and flew a considerable distance. This tank was 1" thick. There was a fire and/or explosion. They found a trace of peroxide. The cause of ignition was unconfirmed. One of the problems was the proper pH control of the material in the aboveground tank. In addition, they plan to nitrogen purge the vent stack. The feed nozzle will be such that it enters below the liquid level. The metal drums will be made-of carbon steel. (2) Control Room and Laboratory Explosion, Dow - An explosion occurred in a lab sewer in Dow's Canadian vinyl chloride monomer plant. A system of tanks was connected to the industrial sewer and one of the valves leaked allowing vinyl chloride to get back into the sewer in the laboratory. The lab was adjacent to the control room for the vinyl chloride process. There was a liquid seal in the sewer line, but this must have blown out with the vinyl chloride vapor. The lab sewers were connected in with the process sewers. The lab itself was not explosion-proof. There were four Dow employees and one from the contractor injured, primarily from burns. Much damage was done to the roof and walls of the laboratory and the surrounding portions of the plant. It is standard practice at Dow to have their laboratories located in the production plant itself. This system permits some of the same employees to do the testing, as well as operation of the plant. (3) Nitrogen Inhalation Incident, Glen Schaaf, BFGoodrich - The Pedricktown incident with the mass autoclave was discussed with the group, emphasizing our commitment to proper vessel entry procedures. Emphasis was placed on obtaining operator commitment to following the procedures. (4) VCM Column Explosion at Convent, Ron Kaminski, BFGoodrich Explained the explosion in the dehydrochlorination column at the Convent facility. (5) Reactor Lockout Device, Glen Schaaf, BFGoodrich - Itemized our work on reactor lockouts so that the bottom valve, the drain, vinyl chloride charge valves and the manway are interlocked in such a way to prevent accidental opening of the vessel when the reactor has a live charge in it. Castell is a company that provides a commercial lock-out systems for the PVC industry. Several companies, especially the English, reported that they have used the Castell system of lockout in their plants. NGC 23257 (6) Polypropylene Plant Fire, Darwin Rhodesf Tenneco - This incident occurred in the Amoco plant near Philadelphia. Propylene and hexane solvents were involved. Two of the mechanics involved in the incident were killed. Amoco does not plan to rebuild this plant. The timing of the accident was very unfortunate. It occurred durina the time that Philadelphia was playing the last game of the World Series. It was very difficult to get people to work overtime and people with limited experience were used. The incident occurred when a recirculation line on a reactor was being cleaned. The normal practice is to put two men on top of the reactor and two men on the bottom of the reactor and clean the recirculation line. After lunchr these operators then change places putting the people who are working on the top on the bottom. They were cleaning a section of the line which extended into the reactor. This was isolated by a valve. They were working on a valve located on the top of the reactor. The valve contained an actuator. The idea was to remove only the valve actuator, since the reactor had pressure on it. However, they removed the wrong set of nuts allowing the valve to completely come apart venting propylene and hexane into the area. The source of ignition was not known. Much damage occurred to the total plant. The blast took out the electrical pumps for fire water. Water for firefighting had to be supplied from a local stream. Propylene is a very volatile solvent. One of the theories for the accident was that overpressurization can cause an explosion. This incident is similar to a mechanical error that took place in the vinyl chloride tank farm in the Premix plant in Mexico a number of years ago. The salvage work at this site was hampered by the asbestos used for insulation. A survey was taken during the discussion of this incident concerning the number of companies that use a blowout protection for vinyl chloride pumps. Ten companies use this type of protection. General Topics (7) PVC Dust, John Vaughn, ICI - He reported that the effect of PVC dust on worker health had confirmed that it is not really a health hazard. An independent organization had studied 800 operators and issued a preliminary report early in 1979. Just last year, an additional 300 operators were included in the analysis and a final report was issued. Some of the pertinent details are included in an attachment. (8) Hazardous Material Notification, Harold Dubeck, Hooker - Harold reported some problems when they installed a new shortstop system in their mass polymerization plant. (They were installing our license technology involving the use of nitric oxide shortstop). Most of the problems occurred because the employees were not adequately briefed on the hazards of nitric oxide. There was a walkout by the people and they stayed out for about two weeks. The mistake was made by not spending enough time with the people explaining the hazards and defining the system and the safety features built into NGC 23258 its operation. They decided to implement this technology without first developing good operating procedures. OSHA even refused to enter the plant during the strike, and the landfill operators refused to take material for three weeks. The discussion indicated there was also a need to inform the local community people when important changes were made which might result in different materials being vented. A survey was taken among the group indicating 13 companies do have a formal plan for informing the local people when changes are made and 13 have informal policies. (9) OSHA Inspection Respiratory Protection, Dave Lull, Diamond Shamrock The major factor during this inspection was the discussion of the practice of permitting fertile women to work in the vinyl chloride and PVC areas. In 1978 and 1979, most companies would not allow that. Since that time, five companies have changed their policies. Now there are only nine companies that do not allow fertile w'omen to work in the vinyl chloride and PVC areas. (10) Operator Training, Steve Brouillard, Diamond Shamrock - Diamond has an excellent safety program at their Independence vinyl monomer plant. The plant was extremely well built during the 1978 period ^ following all OSHA and EPA guidelines. It has a total of 157 ir -/ y t> employees, and have now gone 1.2MM manhours without a lost time accident, so their training and safety program must be very effective. One of the important points stressed in this program is 1 the involvement ofpeople, equipment, and programs. Hoy Henderson, the plant manager, is out in the plant frequently on a day-by-day basis to promote safety. Their people were hired off the street, but were well trained before plant start-up. Now after three or four years, retraining will be done. Programs for training were developed specifically for this plant and they were flexible durino the progress of training to gain the input of the operating personnel. Safety meetings have required attendance and people are paid for this time. Their safety department consists of one loss control supervisor and~ a combination safety and environmental i npar _ Both of these people report to tne numan^resource- 'manager. A survey on operator training is attached. Seven companies indicated that they test operators for certification after training, John Vaughn, ICI - indicated they train operators for three months, and then test to determine if he is certified to do a particular job. (11) Video Tape, John Barr, Air Products - John Barr presented tape made by OSHA and Air Products to explain the hazards chloride to the new employees. A copy of this video tape use will be requested from Air Products. a video of vinyl for our Mr. John Stafford of ICI was /best list of up-to-date data mentioned as the person on angiosarcoma deaths. who has the NGC 23259 (12) Small Reactor Safety, Jerry Brumbaugh, General Tire - Jerry summarized the results of the questionnaire sent out to the members on small reactor safety. A copy of this questionnaire is attached. (13) Computer Control Survey Report/ Jim Gabbett, Georgia-Pacific - Jim summarized the results of the survey on computer safety. Georgia-Pacific have a 98% reliability factor with their computer. The computer improves quality and increases output. A master switch is used to connect the plant to analogue control when required. A copy of this summary is attached. XCI reported that they go through a hazard analysis when any changes are made to computer programs. Georgia-Pacific reported that they are adding equipment to expand the memory of their computer since it is too small. (14) Vinyl Chloride Safety Condensation System, Bernd Terwiesch, * Chemische Werke Huls - They designed a system to handle the emergency relief of large polys. This was commissioned in 1973 with a 200 cubic meter poly. In a runaway charge, a shortstop is added, but its effectiveness depends upon good agitation. Bernd indicated the shortstop affected product quality* They now have a system to handle runaway batches. The kinetics of the runaway reaction is fairly well defined. Usually you have the reaction going from an isothermal to an adiabatic condition. Their system is designed to vent the contents from the poly through a knockout tank, and condenser, into a vinyl chloride accumulator. A supply of cold water is kept in a separate tank to operate the condenser. The condensation system is activated after the pressure in the vessel reaches a predetermined value and if the recovery system does not lower this pressure. In addition, it can be manually activated by a switch. This system design is covered under U.S. patent 4004880 dated January 25, 1977, a copy of which is attached. Since the installation of this sytem, it has been used effectively one time. No venting of vinyl chloride to the atmosphere has occurred. The system is designed to be used for two polys. (15) Fluid Bed Dryer Explosion, Conoco - Conoco reported on a fluid bed dryer explosion which occured in the second stage. The air temperature reached 250C. Normal conditions are 100C. The explosion occurred in the plug flow section. The PVC fused so badly it had to be chopped out with axes. A stainless steel baffle melted. In addition, there was some HCL damage in the dryer. This occurrence is similar to dry blend problems in gaylords where they have experienced hot cores in the center of the gaylord. (16) Tank Car Derailment, Pt, Pleasant, West VA, Everson Weakly, Pantasote"- A copy of this incident is attached. One of the important factors was to keep people of the community informed concerning the progress of cleanup operations. In this particular case, the leak in the vinyl chloride car was patched and the car was then turned upright and returned for repair. The use of portable radios to communicate with a command post was recommended. OSHA people were present, but did not interfere with the operation. -NGC 23260 EPA Update Attached is the following information: (a) Regulatory update - comments by J. Barr. (b) Highlights of a luncheon speech by Garry Baise. Business Matters Next year's meeting will be held in Toronto, Canada. More input will be sought from the European Co. (Their representation seems to increase at each meeting). Officers for 1982: Doug Pry Jim Wallace Henry Rzempoluch H.G. Olson Bill Hager Diamond, Chairman ESSO Canada, Vice Chairman Program Chairman Pan tasot* Ethyl, Secretary Formosa, Treasurer The offices of Secretary and Treasurer are continuing. /3359 j 10/13/81 Ron Kaminski Glen D. Schaaf NGC 23261 Attachment 1 19 August 1981 INSTITUTE OF OCCUPATIONAL MEDICINE EPIDEMIOLOGICAL AND CLINICAL STUDIES OF PQLYVINYLCKLORIDE WORKERS by C A Soutar, S Gauld, M Lloydt L H Copland, J F Hurley ABBREVIATED SUMMARY We have reported previously a medical survey of 818 present and past workers at a factory making polyvinylchloride (PVC) in which we showed that exposure to fine %t PVC dust was associated with a slight average reduction in tests of breathing capacity, and with the presence of small spots visible in X-rays of the lungs* The present studies were designed to identify any chest illness -in men who had worked in dustier plants in the factory but who had not been seen in the previous survey, and to examine similarly men working at a second factory manufacturing PVC; to re-examine the relationship between PVC dust exposure and small spots in the chest X-ray since in the first study there had been some disagreement between expert readers over the interpretation of the X-ray appearances, and to discover how seriously men may have been affected by PVC dust. TwQ hundred and twenty-nine additional men were seen at the first factory, and littl chest illness was found among them* One hundred and twenty-severi men were seen at t! second factory, and even less illness was found in this workforce. Each man was sem a brief confidential medical report NGC 23262 The X-rays were re-read by the same three experienced readers whose results were reported previously, and also by another panel of five readers. The readings confirmed the results of our earlier study, in that PVC dust exposure was found Again, only some readers detected the effect of PVC dust, and the reasons for these differences probably include the slight degree of the abnormalities, which cannot be distinguished in an individual X-ray from changes related to age. These changes of the chest X-ray were slight, on the borderline between, normality and abnormality, and clinical examinations of a group of men who had these spots indicate that the health of their lungs was no worse than that of a group of men of similar agi and smoking habits who had normal chest X-rays (except for a slight increase in sputum)* We conclude that the presence of these spots does not indicate that PVC dusl has seriously affected the lungs. Some men who had experienced relatively high estimated dust exposures were also examined if their breathing tests results were lower than those of other men* The non-smokers selected in. this way all had healthy lungs, but some of the smokers had serious reductions of their breathing tests. This was probably the result of their smoking habit, and there was no evidence to suggest that PVC dust had seriously damaged their lungs* We conclude that exposure to PVC dust has been shown to cause a slight reduction of tests of breathing and slight abnormalities of the chest X-ray, but that there is no evidence that PVC dust has caused serious illness among the workforce, although the possibility of a rare idiosyncratic response to dust cannot be excluded. For details of this work, please refer to Institute of Occupational Medicine Technical Memorandum TM/81/8* NGC 23263 Attachment 2 SUMMARY OF OPERATOR TRAINING QUESTIONNAIRE 9/24/81 The following Is a summary of the 32 responses to the operator training questlonnaI res: 1. What is the approximate number of people In your total work force involved in manufacturing? 0 to 100 100 to 300 300+ 19 8 6 Some responses covered several different plants. 2. Do you have a formal training program for operating personnel: Yes 28 No 4 3- Does your plant organization have a full-time person whose primary responsibility is training? Yes 17 No 15 4. If your answer to No. 3 is "yes," to which functional part of the organization does this person report? (Employee relations, manufactur ing* technical, etc.) Typical responses: a. Manufacturing department (8 responses) b. Employee relations department controls overall program with a coordinator from the manufacturing department implementing most of program at unit level (4 responses) c. Emp1oyee relations d. Safety e. Technical If your answer to question No. 3 is nno,M who in your organization is primarily responsible for training? Typical responses: a. Operating supervisor or foreman b. Safety Department c. Manufacturing engineer d. Personnel NGC 23264 How long does the typical operator spend in the training program? At least half of the respondents indicated the length of their program as 3 to 6 weeks - Page Two Summary of Operator Training Questionnaires 7. Is your program one continuous cycle or Is it divided into several stages separated by practical on-the-job experience? Could you please describe (Example: Orientation/limited training - 1 week, advanced - 1 week, recycle training - 2 days) Typical responses: a. Five phases (1 - Orientation - 3 weeks; II - Departmental Training - 2-3 weeks; 111 - On the Job and Advanced; IV - Self-study Pilot Book Training; and V - Advanced Classroom Training) b. Three weeks operator training; 2 weeks supervisor training 3 months OJT, annual review c. One continuous cycle of classroom and OJT d. Three days formal classroom, 1 month OJT, 2 days recycle classroom training per year e. 90-day apprentice training; 45 days OJT and classroom, qualification courses in process, mechanical, electrical, instrument f. Orientation one-half week; Buddy on the job 2-3 months, probationary period until passes test. 8. Please check those of the following topics which are included in your training program: X Orientation X Safety X Fire Fighting X Process Technology X Instrumentation X Basic Equipment List others not mentioned above: Regulatory (EPA, OSHA, RCRA) __X Industrial Hygiene _X Respirator Protection _X Company Philosophy __X Company Organization EEO, Company Policy. 9- As a part of your operator training program, do you use proficiency tests to evaluate the effectiveness of the program? Yes 22 No 10 10. Do you use tests to qualify operators for promotion: Yes 14 No 18 11. What do you feel are the strengths of your program? NOC 23265 Page Three Summary of Operator Training Questionnaires Typical responses; a. Six weeks formal training b. Locally produced video tapes c. Management support d. Operator input e. Uniform format for procedures f. Company philosophy and attitude 12. What area of your program would you like to improve: Typical responses: a. Supervisor training b. Detailed orientation for advanced program c. Operator retention of material d. Improve higher technology training e. Add formal followup f. Formalized testing g. More formal procedures h. Full time supervisor for training i. Follow-up on a more formal basis 13* Which, if any of these training aids do you use in your operator training program? All of the following are being used to some degree: Fi 1m SIide/tapes Presentation Video Tape Commercially Produced Video Tapes Home-made Video Tapes Mock-up Equipment or Process Area Demonst rat ion I nstruments 14. Do you use video tape recordings produced at your facility by your own people? Yes 11 No 19 If "yes,11 could you please comment on the effectiveness of this technique? Do you recommend this technique to others? NGC 23266 Page Four Summary of Operator Training Questionnaires Typical responses: a. Good for repetitive routine information b. Very good because of local background c. Very relevant d. Prepared by a special training division e. Good - but still learning how to do it f. Only 25% good enough to re-use g. Two respondents said not using but plan to start. 9/18/81 NGC 23267 SMALL REACTOR SAFETY SURVEY Attachment 3 Question No. 1: Most Important Safety Considerations What are some of the most important safety considerations that you would investigate to evaluate the overall plant safety status? Number of (a) Containment of vinyl chloride Replies i. Relief valve and rupture disk system and condition 2 * Emergency relief containment capacity and recovery system 3* Cooling and electrical backup for reactors k. Reactor controls . 5. Unloading and storage and handling of VCM 6. Reactor S/S system 7. Control of reactor bottom valve 8. Emergency shutdown systems 9- Agitator alarms 10. Reactor area manned at all times n. Maintenance records for vessels in VCM service 12. Vessel integrity program (6) (3) (3) (2) (2) (2) (1) (1) (1) CD CD (i) (b) Contingency - preventing fires and explosions in the event of V.C. escape i. Fire protection system 2. Plant layout 3. Presence of safety equipment k. Plant emergency plan 5. Electrical equipment properly grounded 6. Use of fire safe valves 7- Ability to handle large quantities of V.C. gas (6) W (2) (1) (1) (1) (1) (c) Good safety and operational management 1. Up to date procedures - complete operating manual - plant follows procedures 2. Training and education of all personnel 3. Maintenance status - P.M. program h. Housekeeping 5- Attitude of management and personnel 6. Safety organization 7- Operator involvement in safety 8. Inspection system 9- Engineering standards - design criteria being followed 10. Proper raw material storage 11. Regular safety sessions 12. Inter-action between Production and Maintenance (n)<e (10)4(7) (6) (5) (2) (i) (i) CD CD (D (D (d) Indicators 1. Past Records - frequency and severity records 2. Monitoring and emission records 3. Most recent systems safety analysis review NGC 23268 (D (2) (D Question Mo. 2: Reactor Discharge Valve Control How do you prevent the wrong reactor from being opened? 1. 2. 73* 4. 56. 7. 8. *95*10. 11. 12. 13. 14. 15- Operator training and procedures Clear identification of reactors Mechanical locking system - two people to open Discharge port is covered with a locked cover Fixed discharge piping - batch always contained Reactor discharge valve interlocked with reactor pressure Two valves Software interlocks Warning light system - indicates safe to open Electrical interlocks Communications Pressure gauge mounted beside valve Slow opening valves - time to discover mistake Drop valve actuated from reactor top - near pressure gauge and sight glass Working on a locking device Humber of Replies (8V** (S'fr W W (4) (3) (2) (2) (2) (1) ,(D (1) (1) CD CD Question Mo. 3- Charge Volume Control (a) How do you measure water, VCM, catalyst, suspending agents? Water VCM Catalyst Suspending Agents Weight 0 7 9 8 Meter 15 10 0 2 Volume 1 1 3 1 (h) How do you prevent over or under charging? 1. Visual checks on levels 2. Operator training, procedures, signing charge sheet 3- Calibrating meters - maintenance 4. No independent mechanism to prevent over/under charging 5. N/A 6. Dual meters 7. Computer controlled (c) How do you control charging sequence? 1. Operator training and procedures 2. Computer 3. Sequence controlled by mechanical stepper switch 4. r/a 5. Nc answer NOC 23269 (7) (6) (3) (2) (2) (D CD 02) (3) CD (2) (2) Question No. 4: Gasket Replacement Control (a) Do you replace gasket -- 1. After each opening Yes No No Answer N/A 75 7 1 2. After major maintenance 15 0 4 1 3. Once per year 31 Ik 2 Number of Replies (b) Pressure of the pressure test -- 1. After each opening psig - 50, 200, 90, 30, Vacuum, 80% of R/D rating, 15 n Hg vacuum 2. After major maintenance psig - 100, l4o, 150, 85, 120, 150, 135, 120, 180, 60, reaction pressure, rating - 10$ 3. Once per year psig - 170, 175, 180 (c) How often is a manway gasket re-used? 1. Inspected visually and re-used if passes inspection 2. Never re-used 3. 10 - 15 times 4. 10 - 20 charges 5. 50 charges 6. 100 - 150 charges 7. No answer (8) (3) (3) (1) CD (D (2) 0-Rings 10 (d) Are your-manway gaskets O-rings or flat gaskets? Flat N/A 82 Question No. 5' Safety Valve Control on Reactors (a) How often do you inspect your safety valve nozzle? 1. Each time the reactor is entered or opened 2. After every charge 3. Approximately every 3 days 4. Once per week NGC 23270 5. Once per month 6. Once every 30 - 50 batches 7. Two parallel relief nozzles - each with 2 rupture discs and no pop safety valves 8. Do not use safety valves on reac'ors - use double rupture discs 9. No answer (7) (4) CD CD CD (D CD CD Question No. 5: Safety Valve Control on Reactors (b) How often do you test your safety valves? 1. Once per year 2. Every 6 months 3. N/A Number of Replies (14) (i) (5) (c) Are safety valves removed and cleaned after each release? Yes 15 No 0 Yes was the only answer if the question was answered, except' -- "no reactor releases - should be done - no policy." Question No. 6: Reaction Shortstop (a) Do you have a reaction shortstop system? Yes 17 No 2 N/A 1 Automatic Operator No answer (b) Is the injection automatic or done by an operator? 5 16 3 If automatic, what initiates the operation? -- Agitator RPM High reactor pressure -- Loss of power to agitators Over pressure or temperature or loss of agitation -- Loss of agitation, agitator motor, high water pressure, power failure NOC 23271 Question No. 6: Reaction Shortstop (c) Is this system independent for each reactor or a common system for several reactors? Independent Common 10 6 Both systems 1 No answer 4 Number of Replies (d) How often was your system operated last year? Less than 10 6 10 to 100 times 4 Over 100 times 4 N/A 6 Many times the shortstop system was used in non-emergency situations. Daily Weekly Monthly Yearly N/A (e) How often was your system tested last year? 2 1 3 1 13 Question No. 7: Reactor Pressure Control (a) How do you prevent pluggage in reactor pressure transmitters? 1. Water injection 2. Inspection and manual cleaning 3- Solvent cleaning system 4. Dual pressure systems 5. N/A 6. Not a problem (6) (10) (1) (2) (1) (1) NGC 23272 Question No. 7: Reactor Pressure Control (b) Do you have alarms for high pressure? Yes 18 No answer 1 N/A 1 (c) Approximately what percent of normal operating pressure is the alarm set for? 1. Less than 110% 2. Between 110 - 120% 3. Over 120% 4. No answer Question No. 8: VCM Pump Control What protection do you have to prevent remote operated VCM pumps from starting with suction and discharge valves closed? 1. Operator training, procedures, etc. 2. Automatic valves interlocked with pump 3. None 4. No answer 5- CRT display 6. No remote pumps Question No. 9' VCM Storage Tanks (a) Do you have sprinkler protection for your VCM storage tanks? Yes 20 No 2 -- Use monitor nozzles on older installations. No, for some larger tanks Number of Replies (9) (5) (2) (4) (5) (5) (6) (2) CD (D NGC 23273 Question No. 9 VCM Storage Tanks (b) How often are these tanks opened for internal inspection: 1. Once per year 2. 2-5 years 3. 6-10 years 4. Over 10 years 5. No regular basis (many use ultrasonic inspection) 6. No answer Virgin monomer tanks inspected infrequently. Pay tanks inspected more frequently. Number of Replies (3) (8) (3) (2) (3) (1) (c) Have you had any corrosion problems in VCM storage tanks? Yes 4^ No 16 Those indicating they have corrosion problems are in recovered VCM tanks oi\ day tanks, not virgin VCM. Question No. 10: Recovered VCM Handling (a) Do you distill your recovered VCM? Yes No 17 n/a 1 (b) How do you control polyperoxide formation in your recovered VCM system? 1. Short retention time 2. Add an inhibitor 3- pH control - keep basic 4. Keep C>2 levels low 5. No precautions taken 6. No answer (7) (6) (4) (3) (3) (3) NGC 23274 Question No. 11: Reactor Entry Do you require: 1. All flanges blinded 2. VCM flanges blinded only 3. Manway watch 4. Mechanical manway watch 5- Safety belt only 6. Safety belt and wristlets only (3 answered - wristlets only) 7. Safety belt and wristlets with line attached (2 answered - safety belt with line attached) 8. Lab entry analysis VCM/O2 9- Portable analyzer entry analysis VCM/02 10. Respirator worn at all times n. Respirator worn at certain jobs 12. Gloves to be worn Yes No *1* 13 6 1 3 12 1 16 4 1 4n 1 6 11 1 2n 1 2 12 1 No Answer 5 4 3" 3 3 2 14 17 2 15 3 66 13 4 1 X 1 2 1 3 1 6 2 NGC 23275 COMPUTER CONTROL SAFETY QUESTIONNAIRE Page 1 of l1! Attachment 4 Dear VCSA Member, Computer control of PVC plants has very definite safety benefits. However, there are some safety problems which computers introduce which are not readily apparent. The purpose of this questionnaire is to survey computer-operated plants to discover any special problems related to computers, either design or operator interface related, and how these have been solved. 1. COMPUTER/MANUAL OPERATION A) Do you have provisions for independent computer and manual operation? ' 1. No 2. Yes 3. Not Totally 4. Yes 5. Yes 6. Yes B) How do you isolate the computer from the plant during manual operation or when the plant is down for computer repairs? 1. The portion of the computer used for tempera ture control is kept active when the computer is in repair. No manual control is possible in other portion when computer is down. 2. A key switch which turns complete plant control into manual operation. 3. Mechanical disconnect, at I/O and at remote (air supply to valve, etc.) 4. Switch all devices to manual operation 5. There is a relay switching system that is ' activated on computer failure or by manual request. This system deactivates panel push buttons during computer operation and isolates the computer I/O from the device relays during manual or panel mode. 6. Have MANUAL/AUTO switch which electrically isolates computer. Had one incident during trouble shooting of computer when switch was bypassed accidentally. Future design will consider more tangible isolation than switch. NGC 23276 Page 2 of 11 C) Have you had any problems with the computer opening valves or reactors which were out of service for maintenance? ' 1. No operation is possible without computer. 2. No-air is removed from solenoid operated valves when out of service. 3. Once - installed lockout on positioners. 4. One occasion due to human error. 5. No - All valves on reactors down for mainte nance are Mair-failed" so that they cannbt open. 6. Air supply to reactors is locked out during maintenance. D) How do you maintain operator proficiency on manual operation during long periods of computer operation? 1. No manual operation is made. 2. We do not run full production without computers. 3 - Don * t try. 4. Once per month each operator must operate manually for at least four hours. 5. We do not, at this time, have a specific program or method. This has not been a problem for us because our computer up time averages about 98%. 6. Schedule periods of MANUAL operation in order to maintain proficiency. 2. OPERATORS TRAINING A) How do you train new operators? 1. Through education in special lecture program and on the job training. 2. On-the-job with a background of basic theory once familiar with job. NGC 23277 Page 3 of 11 3. Some classroom and theory ~ mostly on the job buddy system. 4. Formal Class Room Training tor approximately four weeks. Then work with existing operator for approximately two months. 5. New computer operators receive most of their training by working with experienced operators. They also spend approximately eight hours with one of the computer programmers for technical instruction about the computer. 6. New operators are not trained on the computer until all other jobs.in plant are mastered. Training involves several weeks of on the job dual operation with experienced operator, on r both MANUAL and COMPUTER modes. B) Do you have refresher training for experienced operators? 1. Yes 2. Yes - Limited to last job rotation otherwise operators are encouraged to keep current at all times. 3. Yes 4. Sometimes when operating procedures are updated. 5. We do not have regularly scheduled retraining classes for experienced operators, but retraining is done if operational performance indicates the need. 6. No C) Sow do you retrain after major program revisions? 1. By lecture and simulation training. 2. Process and staff engineering will assist in this effort. 3. Written, classroom, and demonstration. 4. Systems Engineer conducts training sessions. Includes practice on CRT. 5. When possible, major changes are made gradually and training classes are held to inform operators of the effects of the changes on them. NOC 23278 Page 4 of 11 6. (1) 12-15 hours classroom (2) 1 to 3 days water batching D) How do you communicate minor program revisions to all operators? 1. Either by an official transmittal note or either by starting meeting of the day. 2. Memos and log book. 3. Written - notice and description. 4. Operator log book and notices. 5. This is done through operation department communication channels. (IE., instructions in supervisors instruction log). 6. Have separate log book to record all revisions. 3. FIRST-LINE SUPERVISOR TRAINING A) How do you train new supervisors? 1. By on the job training. 2. Allow upgrade system to cover vacancies. 3. A - Senior operator system leads to promotion. B - No formal method - probationary period. Both - Use outside training programs. 4. New first line supervisors are promoted from the operators ranks and are already familiar with operation. Other training consists of familiarization with maintenance procedures, company policy, etc. 5. New supervisors do not undergo any formal training because they are all ex-coraputer operators. NGC 23279 page o of xi 6. Had problems during startup of plant because supervisors had no time for first hand solo operation of computer, following the classroom sessions. Since then, however, all new super visors selected have come from best computer operators. B) Do you have refresher training for experienced supervisors? 1. Not done usually, except on emergency training. 2,, They participate in all training sessions for each unit. 3. Yes 4. Yes - Same as with operators. In addition they get refresher on supervisory skills. 5. No 6. No C) How do you retrain after ma.jor program revisions? 1. By a lecture and simulation training. 2. Process engineering will assist in this effort. 3. Same as operators. 4. Same as operators. 5. They attend the same training classes that operators attend for major changes. 6. (1) 12-15 hours classroom. (2) 1 to 3 days water batching. NGC 23280 Page 6 of ll D) How do you communicate minor program revisions to all supervisors? 1* By an official transmittal note. 2. Memos and log book. 3. Written and discussions. 4. Same as operators. 5. The same as for operators, through operation department's communication channels. 6. Separate log book to record all revisions. E) Have you had any problems with first-line supervisors losing proficiency with computer operations because of problems in other non-computer-operated parts of the plant?How are these problems overcome? 1. Very few case only. We give them refreashing education and make them supervisors. 2. No - Most first-line supervisors have only a limited working knowledge of computer operations. 3. Some refresher period and assignment with capable operators. 4. No 5. We do not attempt to keep a supervisor completely up-to-date on computer operations. We feel that with two console operators and two senior operators on each shift, it is un necessary to keep supervisors proficient on the computer. 6. Yes - Require supervisors to spend more time in control room and place more responsibilty on outside operators. NGC 23281 Page 7 of 11 4. INFORMATION OVERLOAD A) Have you had any problems of operators being swamped with computer messages and alarms so that some are ignored?How are these problems overcome? 1. No - Only important messages and alarms are kept, so there will be no neglecting possible. 2. Yes - Use of two people helps to overcome problems when the extra person is available. 3. Yes 1. Establish higher threshold for emergency alarms. 2. Have some data indicated, not alarmed. 3. Hardwire really critical alarm. 4. Training employees. 4. Yes - Added a second operator in control room to handle all operations after the reactors. In another plant the supervisor assists the operator. 5. Yes - We are constantly working to eliminate unecessary messages and redundant alarms to reduce the amount of information being fed to the operators. 6. Yes 1. Revised program to reduce number of alarm messages. 2. Use separate printers for messages and alarms. 3. Some critical alarm messages are printed with exposed type in order to make them stand out. 5. OPERATOR COMPLACENCY A) Have you had any problems with operators relying too heavily on the computer to correct all mistakes? How are these problems overcome? 1. No - Cross checks by operators are inserted at important locations. 2. No 3. A- No B~ Yes - have mandatory log sheets to record reaction to alarm. 4. No Not since instituting manual operations once per month. 5. No NGC 23282 6. Yes - Diligent follow up on all incidents (major and minor) where mistakes using the computer are made. Operator making mistake is counseled and other operators are informed. Page 8 of 11 6. MAJOR PROGRAM REVISION SIMULATIONS A) Do you perform any plant-scale simulations when major program revisions are made? 1. No2. On start-up we provide dummy batches to walk through the program. 3. No - Except water'batch tests. 4. No 5. No 6. Yes - Charge full batch quantities of water, VCM, and all additives except catalyst. Use catalyst solvent to simulate catalyst. Simulate alarm conditions, including emergency shortstop. Period lasts from 1 to 3 days. 7. OPERATOR/SUPERVISOR PROGRAM VARIABLE CONTROL A) Do you use an operator/supervisor control key to limit changes to program variables through the CRT? 1. No 2. Yes -- Key switch 3. Yes - Many are not accessible to operators. 4. No 5. Yes 6. Have key - but do not use it. B) How do you limit program variable changes by operations? 1. 2. Some parameters cannot be charged from CRT - engineer has to charge (key-switch). 3. Yes - written authorization and record. 4. Through directed operator CRT keyboard function. MGC 23283 Page 9 of 11 5. By requiring them to obtain permission and key from supervisor. 6. Program variables are changed by engineers. Have not had problems with operatiors changing program variables. Had some problems with operators tampering with FLAG changes in order to get programs to run. Educated operators to high danger of this and revised programs for better operability. C) How do you change formulation variables, such as catalyst and suspending agents? 1. No operators are involved in recipe changes. 2. Done with consultations with process engineering group through supervisor. Engineer normally makes' changes. 3. By CRT, but only as written authority. 4. Process Control Engineer or Shift Supervisor accomp lishes through CRT keyboard. 5. We have programs that allow operators to change the amount of ingredients used within certain limits and this is not a permanent change. Permanent changes to recipes are made by the programmers on request from the technical group. 6. Formulation page has Variables which can be changed from CRT entries. The change must be input twice in order to be accepted. CRT changes are valid for one batch only. Long term formulation changes are made by engineers. 8. REACTOR CHARGE VOLUME CONTROLS A) If you have primary and secondary measurement devices on charge quantities, how do you allow operator acceptance of deviations between primary and secondary devices? 1. Only one measurement is present. 2. Yes - Deviations are questioned by operators, and supervision makes decision. Also process engineering can be consulted. 3. Computer queries, then operator must get visual field verification before proceeding. 4. Variance limits set, but Shift Supervisor has some discretion if barely over limit. NOC 23284 Page 10 of 11 5. We have no secondary measuring devices. 6. Deviation during charge - steps charge, operation must repair problem or deselect one of devices. Deselection procedures are written, with accept able limits. On some chemicals, high value is accepted, on others, low value is selected. VALVE STATUS INDICATIONS A) How do you handle problems with valve status indicators, such as microswitches? Do you override the computer hold or alarm, or do you manually ad.just in the field on each batch? 2. a) We override only after manually checked in field, b) Adjust in field if problem persists. 3. Allow override after field inspection, then write ASAP work order. 4. Device is visually checked in the field before over riding computer hold status. Device is not operated post next work day without repair. 5. If a position indicator fails (valve in the proper position and in contact with switch) an "override" can be placed on the device by using the "supervisory key" until it can be repaired by the I & E Group. 6. Diligent maintenance is required to keep micro switches in good condition. Use override and manual field adjustment to overcome problems. Neither is an acceptable solution, but is necessary for operation. Repeat that follow up on problems must be prompt and diligent. . PLEASE DESCRIBE OTHER COMPUTER-RELATED SAFETY PROBLEMS OR INCIDENTS AND HOW YOU RECOMMEND TO CORRECT THEM. 1. 2. Operators do not always respond to computer initiated emergency type alarms - Computer print-out is reviewed duly by process engineer and recommendations made to production - Training sessions W/operators helps. 3. Preparing thorough fault-free analysis of computer operations on corporate basis. ngc Page ll of 11 4. None 5. In some instances, operators in the field have resorted to manipulating the instrument to process transducers (I to P*s) by hand to force a valve or device to move contrary to computer command. This is a rather simple procedure that, only involves unscrewing the cover and using a finger, nut, bolt, rock or some other object to hold the pneumatic switch in the desired position. Our solution to the problem was to make this act a severe violation of safety procedure with resulting severe penalties for violators. Since instituting this policy, we have had no futher problems. 6. NGC 23286 Attachment 5 i. y yy mr y i TQj,VLIi TQ;WIQ>IrTHi:Si:, ERES.ESXS; SHAlrt;,<QM(E::' lK y^ THERE has been presented to the Commissioner o Parents and Trademarks ___ A PETITION PRAYING FOR THE GRANT OF LETTERS PATENT FOR AN ALLEGED NEW AND USEFUL INVENTION THE TITLE AND DESCRIPTION OF WHICH ARE CON TAINED IN THE SPECIFICATIONS OF WHICH A COPY IS HEREUNTO ANNEXED AND MADE A PART HEREOF, AND THE VARIOUS REQUIREMENTS OF LAW IN SUCH CASES MADE AND PROVIDED HAVE, BEEN COMPLIED WITH, AND THE TITLE THERETO IS, FROM THE RECORDS OF THE PATENT AND TRADEMARK OFFICE IN THE CLAIMANT(S) INDICATED IN THE SAID COPY, AND WHEREAS, UPON DUE EXAMI NATION MADE, THE SAID CLAIMANT(s) IS (ARE) ADJUDGED TO BE ENTITLED TO A PATENT UNDER THE LAW. 1 NOW, THEREFORE. THESE Lexers Patent ARE TO GRANT UNTO THE SAID CLAIMANT(S) AND THE SUCCESSORS, HEIRS OR ASSIGNS OF THE SAID CLAIMANT(s) FOR THE TERM OF SEVENTEEN YEARS FROM THE DATE OF THIS GRANT, SUBJECT "O THE PAYMENT OF ISSUE FEES AS PROVIDED BY LAW, THE RIGHT TO EXCLUDE V. TERS FROM MAKING, USING OR SELLING THE SAID INVENTION THROUGHOUT THE ~ED States. _ NGC 23287 Hit trstiuumy tuiu'rcOf 'J'Xa&e Ae/*et6/bfo de<t Aez/ifa/?,ofc////,.iee/de 3ea./o/de -patent anti UJraitcmark (Office Ao de tz^feoecdafde ojf 0^zd//ij/o/i dst twenty-fifth a Off January iA deft-ea/* of9a/1 o/i e doaJa/zf fa/?,f/<eafa/?,af seventy--seven, anfOffde J0ie/e/ie/zafc/?ce ofde of$f/?ic/t6ca de ftoo d/zefefd a/if first fbf. f 4,004,880 12 cooling means without application of external energy METHOD AND APPARATUS FOR CUSHIONING CONTINUOUS EXOTHERMAL REACTIONS CROSS REFERENCE TO A RELATED APPLICATION flows into the condenser through a blocking valve actu ated simultaneously as that of the gas exhaust line, and an accumulator connected to the condenser. 3 When the pressure in a reactor holding liquefied gases rises excessively either because of unevencss in Applicants claim priority under 35 U.S.C. 119 for Application Ser. No. P 24 287 05.6, filed June 14, 1974 in the Patent Office of the Federal Republic of Ger many. BACKGROUND OF THE INVENTION the reaction sequence or because of failure in the heat exchange, for instance if there is total power failure, or if the heat generated becomes excessive, then accord10 ing to the present invention the liquefied gases arc expanded through al least one gas exhaust line pro vided with a blocking valve responding to over-pres The field of the invention is chemical apparatus hav sure. Because of the expansion evaporation, both pres ing tanks, and the present invention particularly relates sure and temperature rapidly drop inside the reactor. to a method and apparatus for cushioning continuous 15 The gases escaping from the reactor are fed through exothermal reactions with, or in the presence of lique a gas exhaust line into a condenser and arc condensed fied gases. The state of the art of the present invention may be therein. Conventional condensers of the state of the art, for instance boiler-tube nest heat exchangers arc ascertained by reference to U.S. Pat. Nos. 3,636,331; used as condensers. 3,749.555; 3.793,258 and 3,794,471, and- German 20 Those liquids are used as cooling media which will Published Patent Application No. 2.032,700 of Georg boil in the cooling process, and also those which will Schrocdcr et al, having a publication date of Jan. 13, not boil. To ensure that the method of the present 1972 the disclosures of which arc incorporated herein. invention may also be carried out if there is total power U.S. PaL No. 3,793,259 discloses the state of the art failure, the cooling means must be capable of flowing of continuous bulk polymerization of vinyl chloride 25 from the cooling medium supply vessel into the con while the remaining references disclose the state of the denser without requiring external power, such as by art of continuous polymerization reactors. When carrying out exothermal reactions, for instance gravity or by means of compressed gas. Cooling liquids boiling during the cooling process polymerization reactions, unevencss in the reaction allow the mounting of the cooling medium supply ves- sequence or failure of heat exchange may force a resort 30 sel and the condenser at the same height or elevation, to gas expansion from the reaction chamber as the only provided the self-generated pressure or fluid head of way to prevent the reactor from bursting. the cooling medium is large enough to make the same Until recently, such exothermal reactions were car flow also in sucb a case into the condenser without ried out on a large scale in reactors containing about 20 requiring external power. cubic meters. When the pressure in such reactors be 35 The use of media boiling in the cooling process, such came excessive, or when heat generation grew too as ammonia, holds the advantage of the cooling me large, the gases were expanded into a gas vessel at dium supply vessel being kept smaller in size. However, normal pressure or into the atmosphere. The quantities an additional absorption system for the evaporated of escaping gas in the prior art are relatively minor and cooling medium is then required, to prevent the matter generally harmless through dilution into the atmo 40 from entering the atmosphere. sphere. For reasons of safety, the cooling medium supply in Such expansion into the atmosphere is impossible as the supply vessel is large enough to condense the entire regards the recently developed large reactors holding gas content of the reactor. up to 200 cubic meters, as disclosed in German Pub It is important in the method of the present invention lished Application No. 2.032.700 because of ecological 45 that the blocking valves at the reactor and at the cool and safety hazards. Furthermore, appreciable amounts ing medium supply vessel arc opened synchronously of input materials are lost in this manner. High costs and that the supply of cooling medium to the condenser eliminate the feasibility of catching the gases escaping is iarge enough to rapidly condense the gases escaping from a reactor into a sufficiently large gas vessel under from the reactor. This is achieved through mechanical, normal pressure. 50 electrical or pneumatic coupling of the blocking valves SUMMARY OF THE INVENTION at the reactor and at the cooling medium supply vessel. When the reaction in the reactor is computer con Having in mind the limitations of the prior art, the trolled. as disclosed in U.S. Pat. No. 3,636,33 1, then present invention has as an object means for containing opening and closing of the blocking valves at the rcac- continuous exothermal reactions with or in the pres- 5 5 tor and at the cooling medium supply vessel are con ence of liquefied gases, without there being a loss of trolled by a computer. In this system of U.S. Pat. No. same and simultaneously observing ecological and 3.636,331, one uses for instance "feed-forward" con NGC 23288 safety regulations, and to do so in as simple a manner as trol, in which the blocking valves are controlled by a possible. program developed from exhaustive process analysis. This object is achieved in the present invention in 6 0 The blocking valves then arc opened prior to reaching that upon initiation of the reaction, the liquefied gases excessive pressure. Pressure, but also the temperature are expanded into a condenser, then they are con gradient in the reactor may be used as the control pa densed in same, and arc collected in an accumulator. rameter. Such an embodiment is especially reliable in Furthermore, in order to implement the method, the operation. present invention makes use of apparatus comprising at i5 The condensate obtained in the condenser is col least one gas exhaust line from the reactor with a block lected in a pressure accumulator and may be used ing valve responding to over-pressure, a condenser so again. If the condensate tends toward polymerization. 4,004,880 stopper solution arc placed in the accumulator. It is especially advantageous to place the stopper solution in The method of the present invention may be applied to alt exothermal reactions with or in the presence of a `'liquid bag" at the bottom of the accumulator, the liquefied gases, for instance in polymerization reactions condensate being made to pass by means of a dip-pipe of vinyl chloride, ethylene, propenc. butene, butadiene through this liquid bag. This achieves especially good or the like, as disclosed in U.S. Pat. Nos. 3,749,555 and mixing. 3,793.259. BRIEF DESCRIPTION OF THE DRAWINGS The apparatus of the present invention comprising accumulator, condenser, cooling medium supply vessel The present invention is better understood by refer and where desired separator, may* be designed in very ence to the attached drawings, wherein: IU compact form. Parts of the apparatus of the present FIG. 1 is a diagrammatic plan view of the apparatus invention also may be used during the normal sequence of the present invention having one blocking valve in of a reaction in order to recover the residual gases still the gas escape line synchronously controlled along with in the reactor at the end of a reaction taking place one blocking valve in the cooling medium line; therein. FIG. 2 is a diagrammatic plan view of the apparatus 15 As shown in FIG. 3, the residual gas under pressure is of the present invention having two blocking valves in expanded through an additional gas exhaust line 13 the gas escape line and two blocking valves in the cool provided with a blocking valve 14 at the reactor and ing medium line; and actuated by controller 28. In this ease, the cooling FIG- 3 is a diagrammatic plan view of the apparatus medium is not supplied from the cooling medium sup- of the present invention having three blocking valves in 20 ply vessel but rather through line 15. It can flow the gas escape line and three blocking valves in the through blocking valve 16, which is coupled with cooling medium line. blocking valve 14, into the condenser, the moment DESCRIPTION OF THE PREFERRED EMBODIMENTS blocking valves 14 and 16 are opened. When the appa ratus shown by FIGS. 1 and 2 is required, then blocking 25 valves 3 and 5 or 9 and 10 are simultaneously opened With particular reference to FIG. 1, when the pres with blocking valve 17. sure in reactor 1 rises excessively, the gas is expanded A back pressure valve 18 prevents the cooling me through a gas escape line 2 and a blocking valve 3 into dium from flowing out of the cooling medium supply condenser 4. Once blocking valve 3 is opened, blocking vessel into line 15 when, according to the present in- valve 5, located in line 24, is also opened synchro- 30 vention, the cooling medium flows from the cooling nously. thus releasing the supply of cooling medium medium supply vessel into the condenser during a corn- through line 22 from the cooling medium supply vessel plctc reaction in the reactor. 6. Valves 3 and 5 arc actuated by pressure controller The method and apparatus of the present invention 20. In a particular embodiment of the pressure control- surprisingly protects in simple manner the reactor from ler 20, similar to that in FIG. 5 of U.S. Pat. No. 35 bursting in the presence of complete exothermal reac- 3.794,471. the pressure controller receives an electric tions, without requiring discharging explosive or toxic signal output from u pressure transducer in the vapor gases into the atmosphere. The method of the present space of reactor 1 and opens valves 3 and 5 beyond a invention furthermore suffers no less of input materials, given excess pressure and then closes them when the Also, high reliability and safety is achieved for large pressure drops off. The opening of valves 3 and 5 can 40 reactors, while simultaneously preventing damage or also be controlled by pneumatic means. The condcn- jeopardy of any kind to the environment, sate obtained is collected in accumulator 7. To prevent solid or foamed particles from being car- 11 ried along with the gases escaping from the reactor, a FIG. 2 shows the apparatus of the present invention, separator is suitably mounted ahead of the condenser. 45 The reactor holds 200 cubic meters and contains about A cyclone, for instance, or a suitably designed pressure 60 metric tons of vinyl chloride, 110 tons of water, vessel may be used as the separator. activators and suspension means. The temperature in When easily polymerized materials, with respect to the reactor is about 60 C and the pressure is about 10 the particular reaction conditions, arc located in the atmospheres. The capacity of the cooling medium sup- reactor. the latter's blocking valve preferably should be 50 ply vessel is about 2U0 cubic meters and it holds 200 rinsed with a suitable liquid to prevent clogging of the cubic meters of cooling water at about 20 C. A nest of blocking valve. boiler tubes heat exchanger is used as condenser 4. A preferred embodiment is shown in FIG. 2. Besides Sliders with pneumatic control are used as the blocking the elements shown in FIG. 1, there is a further gas valves at the reactor and at the cooling medium supply exhaust line 8 provided with a blocking valve 9. Valve 55 vessel. These valves are coupled through an electrical 9 is coupled to another blocking valve 10, which con circuit. A direct digital control (DDC) system monitors trols the supply of cooling medium from the cooling whether the pressure in the reactor drops fast enough medium supply vessel 6. A separator 1 ) is mounted upon opening blocking valves 3 and 5. If not, the DDC ahead of the condenser 4. system additionally opens blocking valves 9 and 10 and When the pressure in the reactor rises excessively, the control variable is pressure. blocking valves 3 and 5 arc opened First. If the pressure U through failure of heat exchange, the pressure in in the reactor fails to drop rapidly enough, a subse the reactor rises to about 14.5 atmospheres, the pneu quent pressure controller 26 additionally opens block- matically driven blocking valves at the reactor and at trig valves 9 and 10. and more expansion takes place. the cooling medium supply vessel are opened by means When materials are present in the reactor, which under 65 of the electrical circuit. Thereupon within about 10 the particular reaction conditions arc easily polymer- minutes, approximately 180 cubic meters of cooling ized. then rinsing blocking vaives 3 and 9 with a suit- liquid flows through the condenser. The pressure in the able liquid through line 12 prevents elourinu r..in ........... ................. ' NOC 23289 4,004,880 56 utcs, and the temperature drops to about 60 C. Ap sufficient to discharge the cooling medium through proximately 30 metric tons of vinyl chloride are con said means for condensing; and densed in this step. We claim: 1. A method for cushioning continuous exothermal 5 f. means for initiating flow from said cooling medium supply vessel and means for activating said means for initiating flow synchronously with said means reactions by the expansion of gases during an over for exhausting gas. pressure condition during a power failure, comprising: 3. The apparatus of claim 2, wherein said pressure a. conducting a continuous exothermal reaction in a head of the cooling medium is a gravity feed. reactor under elevated gas pressure in the presence 4. The apparatus of claim 3, wherein said means for of liquefied gases; 10 exhausting gas is a first blocking valve responding to a b. at pressures beyond a given safe pressure, expand first given excess pressure and said means for initiating ing said liquefied gases into a condenser to lower flow is a second Mocking valve actuated synchronously said elevated gas pressure below said given safe with said first blocking valve. pressure; c. condensing said gases in said condenser, d. collecting the condensed gases in an accumulator, 15 5. The apparatus of claim 3, wherein said means for exhausting gas are a first blocking valve responding to a first given excess pressure and a second blocking valve responding to a second given excess pressure e. supplying cooling medium to said condenser at a greater than said first given excess pressure and said pressure head sufficient to discharge the cooling means for initiating flow are a third blocking valve medium through the condenser; and 2q actuated synchronously with said first blocking valve f. initiating said expanding and said supplying for and a fourth blocking valve actuated synchronously cushioning said exothermal reaction during an with said second blocking valve. over-pressure condition during a power failure. . 6. The apparatus of claim 3, further comprising a 2. An apparatus for cushioning continuous exother commercial water supply source connected in line bc- mal reactions by the expansion of gases during an over 25 tween said cooling medium supply vessel and said pressure condition, comprising: means for condensing and said means for exhausting a. a reactor having an elevated gas pressure therein gas are a first blocking valve responding to a first given generated by liquefied gases and said reactions; excess pressure and a second blocking valve respond b. means for exhausting gas from -aid reactor beyond ing to a second given excess pressure greater than said a given safe pressure; 3Q first given excess pressure and said means for initiating c. means for condensing connected to said means for flow are a third blocking valve actuated synchronously exhausting and receiving the exhausted gas; with said first blocking valve and initiating flow from d. means for accumulating connected to said means said commercial water supply source and a fourth for condensing and receiving the condensed gas; blocking valve actuated synchronously with said sec e. a cooling medium supply vessel connected to said means for condensing and having a pressure head ond blocking valve. ***** 40 45 50 55 60 65 NGC 23290 --.-n-MinoKni iMnrurtfiiHiT United States Patent (191 Langheim et al. Hi, 4,004,880 [45] Jan. 25, 1977 [54] METHOD AND APPARATUS FOR CUSHIONING CONTINUOUS EXOTHERMAL REACTIONS [751 Inventors: Franz Langheim; Michael Braasch, both of Marl. Germany [73] Assignee: Chemische Werke Huls Aktiengesellschaft, Marl, Germany [22J Filed: May 29, 1975 (21) Appl. No.: 581,935 [30] Foreign Application Priority Data June 14. 1974 Germany ............................... 2428705 [52] [51] (581 VS. Cl................................... 23/230 A; 23/253 A; 23/285 Int. Cl.1............................. B01J 3/02; B01J 4/00 Field of Search .............. 23/285. 230 A. 253 A. 23/284; 62/54; 48/175; 260/78.5 R [56] References Cited UNITED STATES PATENTS 2.775,636 12/1956 Rupp ..................................... 23/285 X 3,078.265 3.652.229 3,794.471 2/1963 3/1972 2/1974 Berger ................................... 23/2K5 X Burke ..................................... 23/285 X Lalinen ..................................... 23/285 Primary Examiner--R.E. Serwin Attorney. Agent, or Firm--Gilbert L. Wells [571 ABSTRACT Method and apparatus for cushioning continuous exo thermal reactions with or in the presence of liquefied gases having a reactor, a condenser connected to the reactor, an accumulator connected to the condenser and a gravity fed cooling medium supply vessel provid ing cooling to the condenser. A first blocking valve which responds to excess pressure is inserted in the line between the reactor and the condenser and a second blocking valve, actuated synchronously with the first valve, activates the flow of the cooling medium through the condenser. 6 Claims, 3 Drawing Figures COOUNG MEDIUM ! NGC 23291 ! U.S. Patent Jan. 25,1977 Sheet 1 of 3 4,004,880 COOLING MEDIUM FIG. 1 NGC 23292 U.S. Patent Jan. 25,1977 Sheet 2 of 3 4,004,880 COOLING MEDIUM FIG. 2 NGC 23293 U.S. Patent Jan. 25,1977 Sheet 3 of 3 4,004,880 COOLING MEDIUM to CD c NGC 23294 Attachment 6 V CM TANK CAR DERAILMENT NOC 23295 Thursday, January 8, 1981 5:30 AM Henry Rzempoluch, Plant Manager, i's contacted by railroad and Informed of VCM tank car derailment. 6:00 AM Rzempoluch visits the disaster site and finds two hopper cars and five VCM tank cars involved. At least one VCM car has a serious leak. 6:30 AM Jim Ferrell, Traffic Manager for Pantasote, and Rzempoluch are at the scene with local authorities and railroad employees. It was decided by local authorities at the suggestion of Pantasote to secure the area. By this time, the railroad had contacted CHEMTREC. 7:00 AM CHEMTREC contacts PPG in New Martinsville, West Virginia. Union Carbide in Charleston is also contacted in case their expertise is needed. 7:30 AM Vapor cloud had increased to about one half acre. Local authorities and railroad evacuate families within one half mile radius. 8:00 AM Ferrell contacts Bob Baker of PPG in New Martinsville; advises him of the situation and requests a response team. Rzempoiuch; three Pantasote production foremen; and Everson Weekley, Safety Supervisor, visit the scene to determine extent of damage. Scott Afr Paks are used By two men who examine the overturned cars. At this point we feel only one car has a serious leak.. We find that dome valves have been completely sheared off allowing VCM to escape. 9:00 AM Rzempoluch and Weekley formulate a program to monitor vinyl leaks. This is done by a Century Unit. A command post is set up at the plant and "walkfe talkies'1 are used to relay information from the scene. 11:00 AM Week.ley returns to the plant and briefs local authorities, railroad officials and Pantasote personnel. Levels in the area are 60 ppm at 500 yards and 150 ppm at 200 yards. Pumps for the city water wells are shutdown since they could prove to be an ignition source and cause an explosion. Public is informed that there is no contamination problem. 12:00 NOON Sheriff Bob Fruth is appointed to read a statement to the press and answer questions on the extent of the disaster. Bill Shaw, Train Master for Chessie System, arrives. Several rail road officials are now at the scene. Hulcher Emergency Service is called in to handle the cleanup. Security is now stepped up and local authorities (sheriff, city and state police) are joined by railroad police. NGC 23296 X1 Page 2 1:00 PM 2:00 PM 5:00 PM 7:00 PM Task force from PPG arrives and are taken to the site to make an assessment. Richard Fleece, Regional Manager for the Chessie System, arrives and helps to coordinate cleanup efforts. E.PA, West Virginia Department of Health, and West Virginia Air Pollution Control Commission by now have contacted us by telephone. A conference L's Held to determine how to patch the leak. We know that all dome valves have been sheared off and that we must plug leaks and clear the atmosphere before cars can be raised. We must also be able to unload the remaining monomer. Regional Supervisor for Hulcher arrives and inspects the damaged car. Meeting held at the Point Pleasant Motor Inn to discuss progress on patching the leak, the possibility of explosion, health hazards involved, security, evacuation, etc. Consensus is that since all valves have been sheared, this is a unique situation. 10:00 AM 12:00 MOON 3:00 PM 5:00 PM 6:00 PM Friday, January 9, 1SS1 PPG states that they are beginning to fabricate a patch. Ron Escue, an employee for Huntington Piping, is called to the disaster site; and he then takes the lead in designing and fabricating a patch. The leak from the Safety Relief on the tank car Is. patched. Gauge and vapor lines are also secured by the same patch. Both liquid lines are patched and the car is ready to be raised. Meeting at Point Pleasant Motor Inn to discuss progress made up to this point. Another task force from PPG1 s Lake Charles VCM plant arrive. 8:00 AM - 3:00 PM Saturday, January 10, 1981 Cars are raised, set Hack on tracks, and moved to Pantasote's yard for unloading on Monday morning. NGC 23297 Applications Radio Communications At Three Mile island On October 16th, August 15th, and July 23rd, Three Mite Island technicians including a health physi cist, a senior reactor operator and two nuclear engineers, entered the Unit 2 Reactor Building at Metropoli tan Edison's Nuclear Station. The purpose of the missions was to assess damage and survey radiation levels in the building, take notes and photo graphs of what was found, and to take samples. Since the required breathing equip ment covers the face, a conventional microphone could not be used. A microphone which would operate in high noise without compromising the safety of the face mask had to be found. Additionally, to prevent radio active contamination, the use of gloves and full-coverage protective clothing meant that a method for completely hands-free radio keying was required. Each man was equipped with a Setcorn GM-312 Face Mask Kit and a Setcom/Portable radio cable assembly to interface the kit to a Motorola MX series radio worn on a belt. The Selcom Kit included a bone conduc tion microphone, a unique device de signed to respond to voice vibrations transmitted through the skull. Since Technicians entering the Unit 2 Reactor Building at Three Mile Island. this microphone was not in the facia! portion of the face mask, mask integ rity was maintained. Also included in the mask kit was a small, light weight speaker suspended over the ear by a nylon loop. The Cable Assembly used for the entry operations included a bodymounted switch for radio keying. This switch was used two different ways depending upon personal preference. In one application it was beltmounted and activated by pressing an arm against it; in the other ap proach it was taped to the individual's wrist and activated by pressing his wrist against his side. Both ways elim inated the need for hand use in keying. In the three entry operations, all conversations and verbal notes were recorded, permitting careful study of the data collected. Communications 5 Hoprinled from January 1981 Communications NGC 23299 ENVIRONMENTAL AIR MONITORING FOR THE 80's Foxboro offers the individual concerned with air monitoring studies a broad capability in instrumentation ranging from charcoal tubes for personnel monitoring to portable infrared or gas chromatographic analyzers for on-site measurements to complete infrared or GC stationary systems for multi-component, multi-location monitoring. If your work involves ambient air measurements of gas and vapors, call Foxboro. The newest addition to the Foxboro line of environmental monitoring equipment is the CENTURY Organic Vapor Analyzer. Air Monitoring Utilizing Portable GC The CENTURY Organic Vapor Analyzer (OVA) provides the operator with continuous data on organic vapor concentrations for screening and survey purposes. Qualitative and quantitative analysis is also possible utilizing the gas chromatographic option. Since most industrial hygiene work is performed in the low and sub parts per million (ppm) concentration range, the OVA incorporates an extremely sensitive flame ionization detector which can, in many cases, analyze to parts per billion (ppb) levels. For analyses which involve monitoring in potentially explosive environments, the OVA has been certified by Factory Mutual Corporation for use in Class I, Division 1 areas. The CENTURY Organic Vapor Analyzer has been proven by years of field experience to be exceedingly durable. Its integral power supply and light weight make it a "go anywhere" instrument capable of dependable operation over a wide range of environmental conditions. The versatility of the OVA has manifested itself in a wide variety of applications, such as: OSHA compliance testing where both qualitative and quantitative data are desirable. Source identification and measurement for fugitive emissions as defined for refineries and chemical plants by EPA. Studies of hazardous waste and spill sites. The OVA can operate in either of two modes. Mode 1--the survey mode--directs sample air directly to the detector. The built-in meter reflects the total organic vapor concentration in the environment being monitored. This mode is ideal to detect areas of high concentration as part of leak detection programs or to define locations requiring further study. Mode 2--the chromatographic mode-- incorporates a sample valve for injection of the air sample into a chromatographic column. In this way, the chemical components of an environmental air sample are physically separated and delivered to the detector in sequence, forming a chromatogram. NGC 23300 Regulatory Update September 1981 Attachment 7 OSHA Carcinogen Policy Amended to meet benzene case, January. Other amendments pro posed and withdrawn. Under review, with 2-3 year goal. Candidate list unlikely. Cotton Dust case stops cost/benefit analysis for health, reaffirms need for rule. Lead Standard Some details of rate retention still unsettled. Qualitative mask fitting proposed. Partial stay until October 11. Medical Records Access Proposal to tighten labor access to data. Labeling Reproposal scheduled for September-October. Women in Workplace General acceptance of employer right to exclude. Reopening of VC/PVC Standard Not expected for 2-3 years. EPA Carcinogen Policy Being rewritten as response policy. Timing uncertain. Vinyl Chloride Standard Administrative changes this fall? NGC 23301 2- General Fugitive Rule Hearings last spring. Water Quality Criteria Revised version out^lowered limit. RCRA Listing - improbable. Superfund repairing limit due next year. All RCRA, Pretreatment, etc. rules reviewed. Flurorcarbon action likely delayed. FDA Still no final action on PVC packaging, BATF request no help. Plasticizer action unlikely until more tests. NOC 23302 SPEECH HIGHLIGHTS GARY BAISE - SEPTEMBER 24, 1981 EPA - VCM REGULATORY STATUS Attachment 8 The 1977 EPA standard contained a 0 goal? however, this is not practical and will probably be replaced with a 1.0 level. O2 chlorination vents - some companies use air instead of O2 but further study is required. Some companies will have no problem complying while others may. Reactor opening requirements will remain the same, but wavers can be obtained on some of the testing required. . The stripping requirements for suspension and dispersion resins will remain at the present levels. This would appears to be "Best Available Technology". . Fugitive emissions - Phase 11 no change in regulation if your plant is following the present guidelines. . Relief valve discharge - will continue to enforce the "Best Available Technology" concept - may divide into preventable and non-preventable categories. Land fills - no problem. No off set regulations. . Administration - will accept the malfunction argument if level of contamination would cause no problems. . It will probably be 2-3 years before the VCM standard is revised even longer if we want to keep bottled up in litigation. /3359j-13 NGC 23303