Document wrNmnd8MexJLMy9REEoO4DV23

DATE JOB December 8, 1971 THERMINOL CONVERSION BULLETIN r' krt`*>niiiiilniiirli ' iiirtihhrrtTl iTilhlitir irirrffl r^L ^--i lii n ^ INTRODUCTION Therminol FR(R) fire-resistant heat transfer fluids have long provided safe, dependable, economical performance for hundreds of users in dozens of appli cations. The presence of poly-chlorinated biphenyl (PCB) in the Therminol FR formulation provided fire-resistance, giving Therminol FR an added margin of safety which was especially desirable in hazardous applications. Most recently, PCB has been identified as a potential hazard to the environment. Monsanto has accordingly elected to discontinue the manufacture and sale of Therminol FR fluids for heat transfer applications, and has undertaken the rather substantial task of converting Therminol FR users over to the non-PCBcontaining formulations, Therminol 55 and Therminol 66. These products offer most of the excellent heat transfer characteristics of Therminol FR fluids, and even a few additional advantages, such as a lower bulk density for improved pumpability requiring Less horsepower. But in fact, Therminol 55 and 66 are not fire-resistant to the extent the Therminol FR fluids were, and due consideration must be given this fact in converting to these newer Therminol fluids. Conversion from a Therminol FR system to a Therminol 55/66 system will be a relatively simple, low-cost procedure in the vast majority of cases. In corporation of proper fire protection equipment will be the only consideration 0585688 Monsanto ---------------------------------------------------------------------------------------------------- . TOWOLDMON0037128 WATER_PCB-00021597 of any major consequence. But even this modification becomes academic, for with the discontinuation of Therminol FR fluids, fire protection equip ment becomes necessary for any and all heat transfer media available today, since the Therminol FR fluids were unique in their fire-resistance. This bulletin is to assist you in making the conversion to Therminol 55/66 as quickly, efficiently and economically as possible. Should questions arise, or if you run into difficulty, Monsanto's Specialty Products Group invites you to call upon its staff of qualified systems engineers for con sultation at any time. Call... (314) 694-1000 collect, and ask for a Monsanto Heat Transfer specialist. Thank you. 0565669 TOWOLDMON0037129 WATER_PCB-00021598 Therminol 55/66 and Your Heat Transfer System Table I. shows the typical physical, chemical and thermal properties of Therminol FR-1 and Therminol 66. As you will note, the two products are quite similar except with regard to AIT, Fire Point and Weight per Gallon. The substantially lower weight per gallon of Therminol 66 means that pumps used in a Therminol FR-1 system will be more than adequate for a Therminol 66 system. In fact, in most cases, pumping rates will be increased with a re sultant saving in horsepower requirements. Therminol 66 has outstanding heat transfer properties, so nothing will be sacrificed from that standpoint in a change from Therminol FR-1. The specific heat and thermal conductivity of Therminol 66 are shown, along with other physical properties, in Table IV. The lower pour point of Therminol 66 (-15F.) means it will be easier to bring the system to temperature for cold startups. Generally speaking, then, a well designed system currently operating on Therminol FR-1 can be converted to Therminol 66 with few, if any, basic changes in de sign -- and without sacrifice to heat transfer efficiency. With the similarity of the heat transfer properties of the two fluids thus established, let us turn to the important differences between Therminol FR-1 and Therminol 66: namely, fire-resistance and oxidation-resistance. Fire-Resistance As stated in the Introduction to this bulletin, the Therminol FR fluids were unique in their inherent fire-resistance. No other commonly used heat transfer medium could be so classified. Even so, the Therminol FR fluids could be made to burn under certain conditions, as indicated by their AIT of something around 1200F. OSB-iblO TOWOLDMON0037130 WATER_PCB-00021599 TYPICAL PHYSICAL, CHEMICAL & THERMAL PROPERTIES The rminol FR 1 The rminol 66 The rminol 55 Composition Polychlorinated Biphenyl Modified Terphenyl Alkylated Aromatic Maximum Bulk Tempe rature Rating (F, ) 600F. 650F. 600"F. Recommended Use Range (F.) 45 - 575F. 45 - 635'F. 20 - 575'F. Pour Point (F) 2 -15 -40 Weight/Gallon (75F.) 11.55 8. 35 7. 4 Flash Point (F.) 350 355 355 Fire Point (*F.) None to Boiling 374 - 392 410 AIT (F,) 1206F. 705 670 Boiling Range (F, ) 620 - 680 644 - 745 635 - 734 Molecular Weight 265 240 340 Expansion Coefficient 0. 00031 cc/cc/^F. 0. 00039 0. 00047 0585691 TOWOLDMON0037131 WATER_PCB-00021600 TYPICAL PHYSICAL, CHEMICAL & THERMAL PROPERTIES Composition ^ Maximum Bulk Temperature Rating CF.) Recommended Use Range (F. J Pour Point (F. ) Weight/Gallon (75F.) Flash Point (F. ) Fire Point (F, ) AIT (*F, ) Boiling Range (*F.) Molecular Weight Expansion Coefficient cc/cc/*F, Therminol FR-1 Polychlorinated Biphenyl 600T. 45 - 575F. 2 11. 55 350 None to Boiling 1206F. 620 - 680 265 0.00031 Therminol 66 Modified Terphenyl 650F. 45 - 635"F. -15 8. 35 355 374 - 392 705F. 644 - 745 240 0. 00039 0565692 TOWOLDMON0037132 WATER_PCB-00021601 THERMINOL6 FR-1 12 10 16 14 12 10 DENSITY - LBS. /G A LLO N VISCO SITY - CENTISTCKES -SO 100 200 300 `100 500 600 700 TOWOLDMON0037133 WATER_PCB-00021602 SPECIFIC HEAT -- BTU/L3 THEHKINOL 66 PHYSICAL PROPERTIES TOWOLDMON0037134 WATER_PCB-00021603 THEHMIROL'*' 55 ' PHYSICAL PHOP5HTIES SPECIFIC HEAT -- 3TU/L3 This point is made to emphasize that, although Therminol 66 is certainly less fire-resistant than Therminol FR-1, it should be viewed in that perspective, and not as "flammable". On a scale of fire-resistance where water would be rated as "0" and ether as "100", Therminol FR-1 would be rated "3", and Therminol 66 would fall somewhere between "15" and "20". It is important to realize that Therminol 66 is less fire-resistant than Therminol FR-1, and to modify the heat transfer system accordingly: it is equally important to understand that Therminol 66 is not a volatile, highly flammable fluid of itself. Protecting the System There are two major fire protection considerations in changing to Therminol 66 -- system leakage and possible tube rupture (in the heater). The former is actually part of the larger subject of good system maintenance, and should be considered regardless of the heat transfer medium employed, A tight, wellmaintained system is usually a good, safe system! Following are some specific recommendations to prevent leakage when you convert to Therminol 66. First, if your system has mechanical seals, you should enclose them, or at least provide a drip pan with a drain to a collection jjump. Canned and sealless pumps offer excellent protection against leakage. The best way to prevent piping leakage is to weld all connections. Where you must have access, use raised-face flanges with appropriate gasketing and high-temperature bolts. Controlling piping leaks is especially important, since fluid-soaked insulation poses a more serious hazard than the leaking fluid, itself. 0585696 TOWOLDMON0037136 WATER_PCB-00021605 Organic compounds such as Therminol 66 appear to create a slow exothermal oxidation reaction with the air trapped inside the voids of the insulating material when system temperatures reach about 500F. Saturated insulation offers a large fuel surface in the face of poor heat dissipation conditions, and this, along with possible catalysis from the insulating material (magnesia, silicate-bonded asbestos or calcium silicate) can cause a temperature build-up in the mass. This temperature build-up can far exceed the autoignition temperature of the fluid, and when the space between the piping and the saturated insulation is exposed to air (i.e., should the insulation be broken for repair, etc.), fire can result. This phenomenon is not fully understood, but appears to occur less with closed cell insulation than with the insulating materials mentioned above. Closed cell materials, then, are preferred, especially where leakage is a possibility despite all precautions. The principle problems areas are near thermocouple connections, valve packing glands, flanges, and wherever insulation contacts horizontal flat surfaces, such as floor plates. To obviate this problem, eliminate any source of leakage promptly. Replace leaky gaskets, use flange back-up rings, re-pack valve stems. Cover insulation where leaks might occur with a hydraulic-setting, oil-resistant cement. In stall valves, where possible, with the stems in a horizontal position so that leaks will drip away from the insulation. And again, use closed cell insulating materials on suspect piping areas. -3 0565697 TOWOLDMON0037137 WATER_PCB-00021606 Tube Rupture In Fired Heaters Generally speaking, where fire protection is concerned, it is best to consult your insurance underwriter for guidance and counsel. Likewise, you will want to discuss your fire safety equipment requirements with top-notch suppliers In that field. Selection and sizing of fire protection equipment are critical. In the case of tube rupture In fired heaters, we recommend the piping of either steam or C02 as a snuffer Into the com bustion chamber of the heater. A minimum one-inch line with a remote manual valve for activation should a fire erupt Internally Is the preferred arrangement. This snuffer system can be automated by the use of an exhaust stack temperature switch. This switch would energize a solenoid valve upon excessive temperature rise, flooding the chamber with the Inert snuffer automatically. It is advisable to set the temperature switch about 100P. over the normal exhaust temperature to prevent nuisance shutdowns. If a steam snuffer system Is used, It Is a good Idea to employ a steam trap to avoid slugging the combustion chamber with water when the system activates, or Is activated manually. Tou can obtain a basic guideline In the selection of C02 protection equipment (again, it Is best to consult your Insurance underwriter) from the National Fire Protection Assn., 0585698 TOWOLDMON0037138 WATER_PCB-00021607 Booklet Number 12, dated 1968. In this publication, It Is stated that a minimum C02 concentration of 46# In the combustion chamber will extinguish a Therminol fire. The following table will be useful In determining the volume of C02 required} Volume of Combustion Chamber - Cubic Feet Calculated Quantity* Temp. Corrected** CO2 Pounds CO2 Pounds OO VA 1 H H-=? 0-140 501 - 1600 1601 - 4500 15 30 15 30 53 106 150 300 * Calculated quantity of C02requlred to maintain 46# concentration by volume at temperatures of 200P. or less. ** Temperature corrected quantity of C02 required to maintain 46# concentration by volume at temperatures of 700F. (Rule of thumbs Increase volume of C02 by 1# for every additional SF. over 200F.) C02 cylinders are available from Cardox Division of Chemetron, Chicago, Illinois. Standard sizes available and approximate costs are as follows: CO2 Pounds Cylinder Size Single Automatic Double Automatic 50 #410 #610 75 #460 #710 100 #650 #980 These units and prloes Include drawings of the units, fully- 0? TOWOLDMON0037139 WATER PCB-00021608 charged cylinders, flexible piping connectors, spray nozzle pressure switch, alarm and automatic control, provided COo release signal Is supplied by customer device. Piping, wiring and Installation labor is provided by the customer. Recharging of cylinders Is available at a cost of $15.00 to $25.00 from a variety of "Fire & Safety Equipment Suppliers" listed in the Xellow Pages of your phone book. In the normal Installation a single cylinder would be released to extinguish the fire, with a second unit available as standby. The second cylinder could actually be used for extended dls- ' charge to maintain maximum concentrations, since some C02 will obviously be lost by leakage from the combustion chamber. This arrangement could prevent re-lgnltlon while the heater is cooling. The Halone Fire Suppression System Is a possible alternative to a CO2 arrangement, and can be used in closed spaces with personnel In the area. Far less concentration is required than with the CO2 system, but the Halone system is more costly to recharge, facilities to do so are not as readily available, and the latter system Is a "fire suppression" arrangement as opposed to a "fire extinguishing" system. Again, we strongly recommend that the advice of fire protection companies be solicited In either case to Insure proper equip ment selection and Installation. Table _____ shows the amounts of snuffing steam required In the combustion chamber for control. If steam Is to be used rather than the other alternatives suggested above. 0585700 TOWOLDMON0037140 WATER_PCB-00021609 R elease In M illio n BTU/hr J o 10 ( 20 30 40 1000 lb./hr. Figure _____ -- Rate of Steam Introduction In 1000 lb./hr. 0305701 TOWOLDMON0037141 WATER_PCB-00021610 Oxidation-Resistance With a Therminol 66 system, some provision should be made to prevent oxidation caused by air contact at fluid temperatures exceeding 200F. This was not the case with Therminol FR fluids, but must be observed for the newer-generatlon fluids. Oxidation can result In sludge formation, eventually leading to loose carbonaceous deposits on heat transfer surfaces. Oxidation Is normally the product of an open, vented expansion tank, and we therefore recommend that the expansion tank be blanketed with an Inert gas. If this is not possible, use a cold seal arrangement as shown in Table _____. An Inert gas pressure of one to two psl should be adequate, as Therminol 66 does not require presurizatlon. You can design the cold seal arrangement quite simply by piping the expansion tank vent to a second tank where the vent line can be flooded with additional Therminol 66 to prevent air contact in the vapor space. In converting from Therminol FR to Therminol 66, It Is Important to remember that many Therminol FR systems were designed with a hot bleed line Into the expansion tank to eliminate moisture accumulation. This bleed line should be eliminated In a Therminol 66 system. Carbonaceous deposits oan also occur at the pump seal face due to leakage at high temperatures. The use of a sealguard flush system or a double mechanical seal Is helpful in preventing this. 0585702 TOWOLDMON0037142 WATER_PCB-00021611 Sy0G*<2^ ~rt^p EXPANSION) .TANK LAYOUT Couo seal uavquT ' __ > r 0585703 | TOWOLDMON0037143 WATER_PCB-00021612 J _1 WERT GPt> BLAWKILTEX) LAYOUT- 05B57CH TOWOLDMON0037144 WATER_PCB-00021613 CONVERTING TO THERMINOL 66 With flre-proteotlon and oxidation-resistance procedures well in mind, let us turn to the matter of preparing the Therminol PR system to accept Therminol 66. The most expedient procedure would be to simply drain and change the system to Therminol 66: however, expedience Is not always the best alternative, and certainly not in this case. Debris accumulated over the years In the system could cause serious problems, especially to mechanical seals, rotary Joints, etc. (see Suggested Expansion Tank Layout, Table ). Any heat transfer system should be drained and cleaned from time to time as a part of normal preventive maintenance. Since a fluid change Is necessary at this time, It would seem logical to use the downtime to clean up the system and start fresh. We would strongly advise you not to simply drain and change, but to take this opportunity to clean your system. Many potential problems will be preempted by so doing. The other reason for cleaning your system at this time Is that the system should be completely purged of PCBs, and a system cleanout Is the only sure way to do so. How to -go about the cleanout Is a matter of choice, but here are some alternatives for your consideration: A. CHEMICAL CLEANING This method is particularly effective In oleanlng heavily-fouled heating surfaces. 0585705 | TOWOLDMON0037145 WATER_PCB-00021614 Cleaning service may be purchased from Dow Industrial Service Company or Halliburton...or, It may be done ln-house using Oaklte cleaning products or caustic soda and soda ash. Consult the Yellow Pages of your phone book for the above services and suppliers. Chemical cleaning procedure with caustic soda and soda ash follows! contact Oaklte for detailed Information on their procedure. Chemical Cleaning - Caustic Soda and Soda Ash 1. Pill empty system with cleaning solution containing 5 lb. caustic soda and 5 lb. soda ash per 120 gallons of water. 2. Initiate circulation* and heat liquid to l80P. 3. Circulate 24 hours, periodically drain fluid from a low point and replace with clean water. Do thi3 until fluid in system is clear (about 24 hours). 4. When fluid In system Is clear, raise temperature to 215225P, stop pump and heater. 5. Quickly drain system, open all vents, and allow residual heat to dry system. ' 6. Assure system is dry. 7. Pill with Thermlnol flalti sulticitaudi &><b , May be desirable to pack pump with Teflon filled asbestos packing to prevent damage to mechanical seal faces. 058S706 I I I TOWOLDMON0037146 WATER_PCB-00021615 B. FLUID FLUSH CLEANING This system is probably the fastest and most effective where heating surfaces are not heavily fouled. It also offers the advantage of not having to intro duce foreign chemicals into the system. With this method, the system is drained of Thermlnol FR, re-filled with Thermlnol (Thermlnol 55 may also be used), 66/ operated for a reasondie period of time, drained once again, and finally, re-charged with fresh Thermlnol 66. Both the drained Thermlnol FR and the Thermlnol 55/66 used to flush the system may then be returned to Monsanto for disposal at no cost to you, assuring you of a PCB-free system, and a fresh start. C. SOLVENT CLEANING This method is satisfactory for cleaning a slightly soiled system, but chlorinated solvents must be avoided. Typical solvents used are acetone, benzene, kerosene and zylol. Do not use trlchlorobenzene or perchloroehtylene. (CAUTION: ALL SOLVENTS SHOULD BE COMPLETELY REMOVED FROM THE SYSTEM PRIOR TO CHARGING WITH THERMINOL 66). 0585707 | TOWOLDMON0037147 WATER_PCB-00021616 Fluid Disposal All drained Therminol FR and Thermlnol 55/66 flushing fluid should be returned to Monsanto for Incineration. This service Is provided at no cost to you, and assures proper elimination of PCBs from the environment. ) All such material should be shipped to: Monsanto Company W. G. Krummrich Plant Sauget, Illinois ATTN: Supervisor, Dept. 246 Please make certain that shipped materials are properly Identified. As stated earlier, Monsanto maintains a staff of qualified engineers who will be available for consultation should you have questions or run Into difficulties. The number to call, again. Is (314)694-1000: ask for a Monsanto Heat Transfer Specialist. Thank you. 0585706 TOWOLDMON0037148 WATER_PCB-00021617