Document by49RKYBZdVbK4G0X08aGoVk0

inter office memo TENNECO CHEMICALS, INC To W. Miringoff from F. Richardson Subject PROCESS ENGINEERING REPORT January, 1975 at Burlington Burlington date January 29, 1975 Copy ttooH. B. Carr W.C. Champion R.S. Cole Dr. L. Gross J.W. McBroom J.W. Poarch P.R. Scarito A.C, Siegel J.T. Sweeney J.J. Zullo P.E. - Burlington Pilot Plant - Fleminqton M^le H0H0P0LYMER STRIPPER REFLUX CONDENSER At a meeting with Manufacturing personnel in late December a proposal was made to install a condenser on a homopolymer stripper according to Scheme B of the attached sketch. This design would cool a stripper batch, by evaporative cooling only, from 220F to 165F in about 18 minutes. At the meeting the objection was raised that the external loop seal might rapidly plug with entrained resin. Furthermore, it was pointed out that, with the lower cooling requirements currently envisioned, the simple " knock-back " configuration might be satisfactory. It was therefore agreed that Process and Project Engineering would investigate the simple 11 knock-back " design (Scheme A) and a design wherein the condenser was installed after the Foam Knock-Out Tank (Scheme E). The requirement was that the batch be cooled from 210F to 190F in the same period of time as required during the December stripping tests. (Cooling from 190F to 165F would be accomplished by cold water injection). Consideration would be given to the amount of cooling accomplished by the stripper jacket. Study of December and January stripping data indicates that combined jacket-cooling and evaporative cooling (to the extent possible without a condenser) will reduce the temperature from 210 to 190F in 20 minutes. About one-half of this cooling is accomplished by the jacket. We have found that the simple knock-back design with one feed line is not suitable because the line, which handles both vapor feed and condensate return, is the limiting factor and it would flood at a very low rate. Also the cooling water rate on the shell side of the condenser would have to be so low that unstable heat transfer conditions would result. As an alternative we have studied a knock-back condenser arrangement with two feeds, shown as Scheme D. In this case all of the condensate and some of the vapor feed would pass through the feed line entering the bottom of the condenser; the balance of the vapor would follow the side-entering feed line. As the total vapor flow changes, the distribution of vapor between the two lines would self-adjust to maintain the bottom line at a mildly flooded condition. This would allow the total vapor rate to go to the flooding limit of the condenser tubes- - about 2000 pounds per hour. COLORITE 010953 page 2 For the installation shown as Scheme E, the condenser can be installed in downflow position since resin carry-over is not a serious threat after the Foam Knock-Out Tank. In this case flooding is not a concern but there is a limit in that the pressure drop in the long line from the stripper to the Foam Knock-Out Tank is so great that the condensing temperature is lowered and the temperature difference for heat transfer is reduced. There is also the question of whether the high vapor rates to the Foam Knock-Out Tank would carry significant amounts or resin; since this a carbon steel system I presume such resin would have to be discarded. To summarize, the cooling times required for going from 210F to 190F , and including jacket cooling, are: Jacket Cooling Only Knock-back Condenser with One Feed Knock-back Condenser with Two Feeds Downflow after Foam Knock-Out Tank Downflow at Stripper (Scheme C) , 40 min. 25 min. 10 min. 8 min. 5 min. So for present cooling requirements there is no great difference between Schemes C, D and E. If more extensive evaporative cooling were desired, perhaps to conserve demineralized water or to reduce load on the centrifuge, then Scheme C is considerably faster than the others. Project Engineering is developing piping drawing and cost estimate for these alternates and we expect to meet with Manufacturing personnel again In the near future. Attempts to locate a similar heat exchanger for the other stripper on the used equip ment market have not been successful. Delivery times for new condensers have dropped from 44 weeks to 24 weeks with tubing availability the limiting factor. More information is expected during the first week in February. STACK DESIGN Exchanged information with Tenneco's Houston computer group on available programs for predicting concentrations of effluents (VCM) down wind of stacks. We will want to use such a program to predict concentrations both on the site and in surrounding areas. It is not certain as yet whether either program we have received will handle both problems. The information which will be developed would be used to determine stack height and location and location of fresh air intake points. CANNED PUMPS FOR VCM SERVICE A list of all pumps handling monomer at Burlington was prepared. The service require ments for each are being assembled from the files. If none of these pumps is in more severe service than that of the canned pump which has been ordered for testing at Flemington, then there appears to be no need for a second test at Burlington. COLOR!TE 010954 Page 3 REACTOR BAFFLE ORIENTATION We were asked to check the baffle orientation in the homopolymer and copolymer reactors. It was considered that any differences found might be correlated with product variations and that the baffle orientation could then be deliberately changed to obtain desired characteristics. So far we have been able to check all of the homopolymer reactors except one (10, 11, 12, 13, 1-:, 15, 16)* There were no observable differences. On the copolymer side we have checked only, 1, 2, 6 and 9. Reactors l and 6 seem to be the same as those on the homopolymer side. Reactors 2 and 9 have baffles that are rotated slightly so that the baffle tips are perhaps moved about 3 inches with respect to the vessel centerline. This doesn't appear to be a significant difference; the tendency would be to increase turbulence near the center of the Reactor and decrease it near the wall. It is interesting that operating personnel claim that reactor Number 2 requires more frequent cleaning because of rapid build-up on the walls; this started, they believe, after the baffle was changed. Reactors 2 and 9 were cited as harder to clean than others but this could be due to many reasons. The remainder of the Reactors will be checked as they are available. FDR/km F. D. Richardson COLOR!TE 010955 BY-----CHKD. BY____ DATE I sU BJ Vtr'iOni brr-YC'*i'\a- SHEET NO........ I OF___[ DATE______________ XticVn-Ufl^ tn__of Unmoral v m 4s-------------- JOB NO------------------------------- ______________ ^ -U-I Te KP r*>k. ^&Ke.r*\e ft V Kmtk-'5u-k w Ta R*c*ve*e^ Ce^pr^ifa-v" COLORITE 010956 F. 0. RI irdson FROM January 1 9TO January 31. 197 THTIirSCO -INTERMEDIATES DIVISION-NGIIEHRIUO TIMS DISTRIBUTION - MONTHLY (SALARY) 3s HOJSCT RJI-32R DEI-377 AC COUTH? .NUMBER JOB DESCRIPTION Homopolymer Stripper Reflux Condenser SUN MON TUE WED THU FRI SAT TOTAL 80 'El-377 Stack Design Study * 38 iE!-377 Canned Pimps for VCM Service 18 )E1-377 Reactor Wat'er Fill for VCM Displacement Check orientation of Baffles in Suspension Plant Reactors ' Miscellaneous Meetings * - 8 1 8 8 Hoiiday off due to Death in Family 8 ,6 COLORITE 010957 t ' , 1 ENG. FORM #29 * *. - TOTALS 184 L* A. Sch-ipe 11 FROM January S, 1975 PTO January 31, 197 'ROJECT rji-BSR OcX-377 TENII2C0 .INTERMEDIATES DIVISIoraiGIIESRING TIMS DISTRIBUTION - MONTHLY (SALARY-) ACCOUNT . KUMJER JOB DESCRIPTION VCM Analysis - Vent Condenser SUN MON TUE WED THU FRI SAT TOTAL 1 1 14 1 8 OC Coating, LOP 1035 42 11 15 D^X-37 7 Df2-377 Foam Resins, 1750 and 1756 VCM Decay in Dispersion Resins 250 Stripping Trials * 315, LOP 1045 88 8 24 1 1 1 1 2- 6 13 2^ 4 S 2 24 Dfi -37 7 * BR-505 315 StrIppinq Trials Orientation 11 12 24 24 18 IS 17 2i 3 99 COLOR!TE 010958 t * ENG. FORM #29 Annual Physical Exam. * 3 -. TOTALS 32 32 32 32 32 3 ISO A! 3 M. WT11 ifetd FROM January t, 1975 TO January 31, PROTECT lEBBER THNNSCO intermediates DlvisiorLNGI; ESRINO TIMS DISTRIBUTION - MONTI ELI (SALART) ACCOUNT . NUMBER JOB DESCRIPTION Flemlngton Conversion SUN MON TUE WED THU FRI SAT TOTAL 160 Sick * 16 Hotiday 8 \' " COLOR!TE 0 1 0 9 5 9 i i \ f i . i t 1 1 1` . ( ! % ENG. FORM #29 -. * TOTALS 184 'AT13 Vrr Mirln'">ff FROM January I, 1975 TO January 31. 197 THNN2C0 .intermediates DivisiotfRIGI: ERRING TIME DISTRIBUTIOII - MONTHLY (-SALARY) PROJECT J.TJI-3LR DEI-377 ACCOUNT .number JOB DESCRIPTION SUN MON TUE W1SD THU FRI SAT TOTAL 120 DEI-406 ' Waste Treatment Foam Resins NP 1 1042,1043 * 12 20 Hoi Iday BR- 505 NPI 1041 . Qua!ity Problems * Hoiiday V 12 12 8 COLORITE 010960 ;_ !` * 4 i ii i Ei-----;--------------------1 rj \ f ENG. FORM i} 29 * * -. TOTALS 184