Document jy80rQqrM1DxOa7rQmRwjB6vQ

To: P. J. Kober IVnWvVVm Communication From: D. A. Doherty Date: May 9, 1988 Subject: VCM Efficiencies Cumulative VCM Efficiency for fiscal year 1988 (through April) is 1.01259. Budgeted efficiency for fiscal '88 is 1.00756. An investigation into the VCM efficiency was undertaken by Op erations, Engineering, and other plant personnel. The inves tigation included a brainstorming session to develop a list of possible causes of efficiency problems.(The list is attached.) The only major cause of reduced efficiency identified is the difference between the KCS Railroad scale (used to weigh VCM cars) and the Aberdeen railcar scale (used to weigh PVC product cars). The effect of the scale difference on the reported monthly effi ciency is an unfavorable increase of about 0.006 (based on a recent scale weight comparison). April year-to-date efficiency adjusted to eliminate the effect of scale differences is 1.00678. In order to estimate the difference between the Aberdeen railcar scale and the KCS scale, thirty-six VCM cars were weighed in Aberdeen during a two week period in January 1988. These cars were weighed both before and after unloading. The billed weight from the KCS scale averaged * 946 pounds more than the Aberdeen scale weights. This difference does not include the heel weight of 750 lbs. assumed left in the car for billing purposes. The actual difference in the two scales averages 1,717 lbs. when the heel weight is included. i Table I lists the weights for the railcars received during the two week period as measured by the KCS and Aberdeen scales. Also included in this table are average differences between the KCS and Aberdeen scales. Graph I illustrates the consistently higher values from the KCS scales. KCS guarantees their scale to 1% tolerance. An average 1.0% overweight (as compared to Aberdeen scales) would result in an efficiency of 1.01 even if the actual plant efficiency was perfect. The Aberdeen railcar scales are certified quarterly to be within 0.1% of actual weight. The effect on efficiency is based on the difference between the incoming and outgoing scales regardless of the "correct" weight. Aberdeen efficiencies are sensitive to changes in the difference between the VCM measured weight and the PVC product measured weight. Several methods were devised to try to detect changes in the KCS scale so that efficiency swings caused by a change in the VAB.0001105515 VCM Efficiencies May 16, 1988 Page 2 railroad's scale could be explained. The only method proven effective is to check VCM car weights against the Aberdeen scale. Weighing VCM cars as done during this investigation cost $140 per car. The cost for weighing all VCM cars would be approximately $28M per month. Volumetric methods of calculating railcar contents were Investigat ed to see if the KCS scale could be monitored that way. VCM cars were gauged and the contents of railcars was calculated based on outages and measured temperatures. Outages and temperatures for loaded cars were provided by the LCVCM plant and similar measurements were made in Aberdeen for a few cars. Volumetric methods do not appear accurate enough to detect a small (but significant) change in a rail scale's performance. Table II shows calculated contents and comparisons to scale weights for many of the railcars recently shipped to the Aberdeen Plant from LCVCM. Several graphs were constructed comparing the KCS scale weights against the Lake Charles and Aberdeen calculated volumetric weights. Mo obvious correlation exists between the calculated content and scale weight. Based on the 36 cars weighed by KCS and checked at Aberdeen, approximately 50% of the Aberdeen Plant's reported inefficiency is accounted for by the scale difference. A cumulative efficiency adjusted by assuming a similar scale difference throughout the fiscal year, is favorable compared to budget. A D. A. Doherty Contract Process Engineer Aberdeen Plant slh cc: RWS, DCS, CWT, CJMc, AEB, DFJ, LDH HOUSTON: RRS, VAB.0001105516 * f mm TABLE I A RAILCAR NUMBER KCS FREIGHT WEIGHT POUNDS KCS BILLED WEIGHT POUNDS ABERDEEN NET WEIGHT POUNDS DIFF. AB NET--KCS BILLED WT. /HEEL. BILLED WT 1++*+ ##***###***##*#****###*****####**** | Wr * > |WTT )>it 1 u n 1 __r * mta |||r| 9 * ttrtJ * ltHf nrw .W Ml MM w* M m W *** WH nt TM mi* M-- +** **** ............ ***** *" * ' UTLX2185 UTLX823S UTLX8217 TIL X0002 UTLX8242 UTLX2235 UTLX2195 TILX0014 TILX0027 UTLX8264 TILX0000 UTLX8250 UTLX8214 TILX0016 UTLX2196 UTLX80S9 UTLX82i1 UTLX8198 UTLX8136 UTLX8266 UTLX8066 UTLX2012 UTLX8188 UTLX2087 UTLX8262 UTLX8261 TILX0007 UTLX2267 UTLX2041 UTLX8263 UTLX2249 TILX0004 UTLX2266 TIL X 0031 TIL X0013 UTLX2069 *** 4wl 177300 177100 179100 175343 177303 176883 177863 176303 176203 178783 174100 178400 178500 175100 177300 177400 177300 177100 179000 179600 179300 178600 178900 177400 178800 178200 175100 178500 179400 180000 178800 176100 179200 175100 176300 178500 m-m* m M *+** ** ***** 176550 176350 173350 174593 176553 176133 177113 175553 175453 178033 173350 177650 177750 174350 176550 176650 176550 176350 178250 178850 178550 177850 178150 176650 178050 177450 174350 177750 178650 179250 178050 175350 178450 174350 175550 177750 **+4+ * Iftl 176270 175710 176590 175113 176113 175693 176613 175073 174953 176793 173150 176510 175950 173530 176190 176030 175430 176370 177910 178230 178070 176530 177430 176310 176633 1 /' *.J V-. 174313 175313 176633 175373 176333 173893 177473 175193 173893 175533 Mlrt *** -1030 -1390 -2510 -230 -1190 -1190 -- 1250 -1230 -1250 -1990 -950 1- 890 -2550 -1570 -- ill 0 -1370 -1870 -- 7 3 0 -1090 -1370 -1230 -2070 -1470 1- 090 -2167 V O /rw") v -ltv -.L -230 --640 1 u-- / il t*`F t"\ U ui V -440 --440 i p *a --500* 4 R O- *+ k* it )(J-r 4* 4+ -.*'h * m ** > 1-- 4 *. il'f rm *** ** i 1 ( I -114 0 -1800 -820 -360 -620 1 L (-* > r'\ . . *l"-* ' ' -*-* J ` JiS 4 *+* P i1 Ji iJ * fe4 t "" . * ' w* *><44 '* * *-- A4 \j MH 1 "V 11 * iiW 1 ` J * t J_ 4l # 4 * "1 4-1 4 i >y / i i| . 'i 'l t * fi | 44 r **4f ' ' -H ' -P ' -*** i ! -u /f I . h - nt *i** T 1 11< < I.* .1 1j | , ... 4* *t I- * I lit V t 2407 if rtv * * I * *v .iL t * ft i4* - ItfM 4III4 4|ff 1*4*1 * *M ll*l ' -n n AVERAGES 17 175899 ; l VAB.0001105517 I- A TABLE II RCAR NO. L.C. CAL. KCS SCALE VOLUME WEIGHT POUNDS POUNDS ABERDEEN KCS VS L.C. CAL. VOL. WT. DIFF. POUNDS POUNDS UTLX8Q46 UTLX8070 UTLX8223 UTLX8239 UTLX2068 UTLX8067 UTLX2271 UTLX823I UTLX8109 UTLX8212 UTLX8251 UTLX2150 UTLX8259 UTLX8250 UTLX2012 UTLX2267 UTLX8107 UTLX8078 UTLX8197 UTLX2172 UTLX8236 UTLX8261 UTLX2249 UTLX8263 UTLX8225 UTLX2196 UTLX8216 UTLX8084 UTLX8258 UTLX8073 UTLX2069 UTLX1702 UTLX8256 UTLX2189 UTLX2087 UTLX8264 UTLX8209 UTLX8238 UTLX3121 UTLX8269 UTLX8207 UTLX0482 UTLX8200 UTLX2239 UTLX8220 UTLX8235 UTLX21B5 UTLX8204 UTLX8208 UTLX8271 177690 177931 177386 177536 177989 178108 178141 177730 177619 178222 177788 178330 178009 178132 177989 178504 177989 177852 178147 178754 177627 177409 178079 177852 178019 177903 175828 176554 176471 177852 178867 177900 177677 178821 178372 178105 177867 178051 177569 177543 177741 178655 177409 178142 178060 177439 178097 177627 177559 177574 178200 177700 178400 176800 179000 179500 178200 178500 178800 178800 178800 176900 178300 177900 178000 177950 178000 179900 179000 178900 179200 179500 179400 179300 179600 .178600 179500 178000 178100 179500 179100 173100 179300 179100 179400 179400 178600 176200 179900 178600 179000 179200 178900 178500 179600 178000 179000 178700 178800 179100 177533 177533 t 177578 178257 177815 177910 177890 177651 -510 231 -- 1014 736 -1011 -1392 -59 -770 -1181 -578 -1012 1430 -291 232 -11 554 -11 -2048 -853 -146 -1573 -2091 -1321 -1448 -1581 -697 -3672 -1446 -1629 -1648 -"*233 4800 -- 1623 -279 -1028 -1295 -733 1851 -2331 -1057 -1259 -545 -1491 -358 -1540 -561 -903 -1073 -1241 -1526 KCS SCALE VS ABER. VOLUMETRIC WT DIFF POUNDS -667 -1267 t- v% - * % -- 1922 --043 -1285 -1490 -1510 1451 VAB.0001105518 A TABLE II RCAR NO. L.C. CAL. VOLUME POUNDS KCS SCALE WEIGHT POUNDS ABERDEEN CAL. VOL. POUNDS KCS VS L.C. WT. DIFF. POUNDS UTLX8215 UTLX2246 UTLX8042 UTLX8091 UTLX8188 UTLX8137 UTLX8266 UTLX2093 UTLX8045 UTLXOlOl UTLX8096 UTLX8089 UTLX8247 UTLX8231 UTLX2068 UTLXS246 UTLX8229 UTLX8060 UTLX8067 UTLX8258 UTLX2196 UTLX0294 LJTLX2041 UTLX8206 UTLX8201 UTLX8226 UTLX8269 UTLX8121 UTLX8220 UTLX8247 UTLX8089 UTLX8199 UTLX2140 UTLX2172 UTLX8204 UTLX2271 UTLX8091 UTLX8057 UTLX2160 UTLX8137 UTLX2167 UTLX8188 UTLX2246 UTLX2248 UTLX21S0 UTLX8266 177635 178111 177794 177672 177837 178012 177559 178707 178250 178776 178234 173486 178173 178120 178381 178044 178135 178549 178289 178081 178542 177365 177597 177567 177719 177406 177730 177783 177822 177763 178073 178050 178217 178353 177814 178126 177846 178043 178111 177642 178818 178147 178419 178338 178336 177122 178500 178700 178200 178300 179300 178500 178400 178300 179100 178500 179000 178200 178900 177300 177700 178400 177000 179100 180300 180700 178200 178900 177700 178300 179100 177900 178000 177800 177900 178200 178700 177300 179100 178300 178400 177900 177800 178600 178800 179000 178300 178400 178000 178300 176600 1 79000 f AV6 . = 4 -865 -589 -406 -628 -- 1463 -488 -841 407 -850 276 --766 286 --727 820 681 --356 1135 -551 -2011 -2619 342 -1535 -103 -1233 -1381 -494 -270 17 - -78 --437 -627 250 -883 53 -586 226 46 -557 -689 -- 1358 518 -253 419 38 1736 -1878 578 KCS SCALE VS ABER. VOLUMETRIC WT DIFF POUNDS V -837AB.0001105519 BRAINSTORMING LIST CAUSES FOR VCM EFFICIENCY PROBLEMS 1. Railcar weights are from KCS for Vinyl - unloading procedure A 2. Low-mole resin: Product mix affects efficiency/High tempera ture reactors have more losses. 3. Recipe changes - chemistry-(lock up VCM?) 4. Strapping tables, etc. and Inventory procedures, way we measure what Is In reactor 5. Compound - Dryblend resin consumption 6. Send back more VCM In cold weather 7. Sphere gauge, etc. not accurate 8. Leaks and losses VCM, baghouses, and at Tank Farm 9. Calibration and reporting problems 10. Impurities In Vinyl 11. Reduced Impurities In PVC 12. Losses to ponds. Incinerators 13. No RVCM In 5305 VAB.0001105520