Document VOGD3z7jg8KELjvzpG76z4m4

COPT No, NEWARK PLANT PIGMBT COLORS RESEARCH AND DEVELOPMENT REPORT TITLE EVALUATION OF ENCLOSED DISCHARGE FILTER PRESS ________ TO REDUCE AREA FOGGING^ FINAL REPORT Wbtfk Done % John N, Birmingham Report Written by John N. Birmingham ^ Project Code 4656-700 Period Covered: January 1976 - February 1977, part time ABSTRACT During periods of cold weather, warm press effluent in the batch processing area causes excessive steam generation. This results in a hazardous work environment and inefficient use of the area. A filter press was installed which by means of valves on the plates and a third eye in the plates and frames provided enclosed discharge of the effluent. It was planned that by use of enclosed effluent discharge, steam generat ion would be markedly reduced. This type of filter press was not suitable for Newark plant operation. Difficulties included filter cloth alignment, effluent line pluggage and inadequately designed valves. Although solutions to most of the problems appear possible, the effort required would not be Justified. Furthermore, sustained operation of the press would still be difficult for Manufacturing, r et ur n t o JACKSON lAEORATORY FILE ROOM N35362 DUP050108963 TABLE OF CONTENTS INTRODUCTION OBJECTIVE SUMMARY AND CONCLUSIONS PROGRAM DISCUSSION APPENDICES 1 2 3 4 5 6 7 Page 1 1 1 2 2 7 8 9 10 11 12 13 -17 RETURN TO SON LANS1', RLE ILO'LO DUP050108964 INTRODUCTION: Batch manufacturing at Newark includes dewatering and washing of pigment slurries using plate and frame filter presses. Many of these slurries are warm when filtered, in some cases haying temperatures as high as 190F. The filter presses have individual effluent lines from the plates, all of which discharge to the floor drains. During periods of cold weather, roughly October through March, the warm press effluent causes excessive steam generation In the work areas. This creates a hazardous condition due to limited visability and prevents optimum utilization of other equipment in the area. Study of the problem has shown that most of the steam is caused by the hot effluent flowing over the cold floors in the work areas. Steam is formed due to the low temperature of the floor and the Immediate air. The amount of steam is increased due to the wide floor area over which the effluent is allowed to flow. OBJECTIVE; Evaluate the operability of a filter press capable of both open and enclosed discharge of effluent. Using the enclosed discharge process, determine the impact of efficient effluent removal on steam generation. SUMMARY AND CONCLUSIONS: A filter press was installed which combined three-way valves on the plates with a third eye in the plates and frames. This enabled the press to be operated either as a standard open discharge press or as an enclosed effluent discharge press.* * This type of filter press was not suitable for Newark plant operation. Major problems occurred in the following areas: Filter cloth alignment. Misalignment of the filter cloths frequently resulted in pigment being forced into the effluent eye of the press. This resulted in yield loss and pluggages. -1- DUP050108965 o Effluent line pluggage. The small diameter effluent lines in the plates often plugged. This reduced the filling and washing efficiencies of the press and required periodic service outages for cleaning. 0 Plate valve design. Both valve designs tested presented operating and maintenance difficulties. Although solutions to most of these problems appear possible, the technical effort required would be excessive. Fur thermore, sustained operation of the press would still be difficult for Manufacturing, Therefore, the press is to be reworked to operate as a standard open discharge filter press. Due to the poor operability of the press, the effect of closed discharge effluent removal was not evaluated. PROGRAM: This report will serve to close out R & D work on a filter press capable of both open and enclosed discharge of effluent. It was agreed with Manufacturing that the press would be reworked to standard open discharge service* Recommendations and information have been supplied to Manufacturing on the work required for con version (ltr. JNB - TRB, 2/17/77 - Appendix 7). R & D will reactivate the trough project originally studied. Work on troughs was deferred during testing of the enclosed discharge press. The trough project is also based on achieving efficient removal of the warm effluent to reduce steam generation. DISCUSSION: During January 1976, press 25 was modified to be capable of both open and enclosed discharge of effluent. To do this, polypropylene plates and frames incorporating a third eye for -2 DUP050108966 effluent removal were Installed. A special four inch thick adapter slab was fabricated with a side discharge fitting. This enabled three-eye operation in a press originally constructed for two-eye service. The element arrangement is shown in Appendix 1. The plates were ported and equipped with three-way valves to provide both open and enclosed discharge. The porting and method of valve operation are shown in Appendices 2 and 3* All required polypropy lene material was purchased from Lenser America, Inc., Whippany, N. J. as per Appendix 4. Use of polypropylene plates and frames required alteration of the press closure device. The press is closed and sealed by means of a hydraulic ram. When used with the previous iron elements, the press was sealed by the hydraulic ram to 1200 psig hydraulic pressure. At that point, a lock nut on the ram was secured and the hydraulic system was turned off. During operation, the ram was locked in a stationary position and the hydraulic system was not energized. Due to the relatively high thermal expansion of poly propylene, this system was not usable. When filling with hot slurry, the press length would expand and increase the stress on the press skeleton. This could result in permanent damage to the skeleton. Upon switching to cold water washing, the press length would contract and lower the clamping pressure. This could result in leakage throughout the press. The ram hydraulic system designed for the polypropylene filter press is illustrated in Appendix $ The lock nut was removed to prevent securing the ram in a fixed position. Valves and a pressure switch were installed in the hydraulic lines. During operation, the control switch is left on and the pressure switch controls the pump. The low (1050 psig) limit on the switch restarts the pump, thereby preventing underpressurizing the press. When hydraulic pressure reaches 1200 psig, the switch shuts off the pump. If pressure continues to increase due to thermal expansion, the relief valve limits the maximum pressure at 1300 psig. This ; prevents dangers due to over-pressurizing the press. The system worked well during the year of operation and is being used on all other polypropylene press conversions. - 3- DUP050108967 During operation, three main areas of difficulty were encountered: filter cloth alignment, port pluggage and valve design. Filter cloths were misaligned primarily because of inaccurately cut filter cloths and poor accessibility of the efflu ent eye. Filter cloths are cut from bulk material on the plant. Due to the limited facilities available for this work, location of cut eyes on the cloths is erratic. This type of error is marginally acceptable with the two eye presses now used. However, with a third eye in the lower corner of the press, alignment of the upper two eyes often results in the third eye being off center. The problem is compounded by the location of the third eye. These eyes are on a level with the platform upon which the operators are standing. Therefore, in aligning the upper two eyes, the misalignment of the lower eye can pass unnoticed. The result of filter cloth misalignment is illustrated in Appendix 6. The error in the cloth eye position was always above and normally toward the center of the desired spot. This reduced the gasket area of the cloth which separates the frame chamber from the effluent eye. As the slurry pressure increased during the fill cycle, pigment could be forced past the reduced gasket area into the effluent line. This resulted in product loss and pluggage of effluent lines. Pigment could also be forced through to the plate filter area, resulting in bleeds throughout the press. An attempt was made to correct this problem by gluing the filter cloths to the press. A mastic produced by 3JVt was used to secure the two layers of filter cloth together and to the polypropylene plate. The mastic performed well and prevented misalignment. However, several difficulties exist. The gluing operation is time and labor intens ive. Based on the time required by R & D during the test, 24 hours by two men would be required to secure an entire press. This would be required approximately once every two months. During regular operation, individual defective cloths are replaced during the unloading of the press between batches. This would be difficult using the gluing procedure. Further, the problem of miscut filter cloths would still exist. -4- DUP050108968 A possible solution which was not evaluated is the use of precut cloths supplied by an outside vendor. Use of ties on the out side edges would prevent cloth misalignment. This was not pursued due to Manufacturing concern over increasing tramp material into the product, The second major area of difficulty was pluggage of the plate ports. Causes of the pluggage were pigment entering the lines and the design of the lines in the plate. Pigment could enter the lines due to either the cloth misalignment discussed earlier or occassional bleeds through defective cloths. Since this press was used in ''KROLOR" service, hardened chips of silica and pigment from the strike vat also occasionally got into the lines. The design of the lines also promoted pluggage. As shown in Appendix 2, the lines were 1/8" diameter and the line going from the plate grid area to the valve includes a 105 degree turn. Due to the causes discussed, all valves on the press gradually plugged, in some cases completely stopping flow through a particular plate. This lengthened the fill time and reduced press washing efficiency by limiting the maximum flow through the press. To correct the pluggage, the press had to be taken out of service periodically, its valves removed and the lines cleared with a high pressure water jet. A possible solution to this problem would be to enlarge the diameter of the ports and to machine a cavity where the 105 degree turn occurs. The cavity would modify the effect of the sharp turn between the two port lines. However, this solution would require extensive reworking of the plates. Also, enlarged line diameter would weaken the plate. The final area of difficulty was the three-way valve used on the plates. The original valve tested was black phenolic model supplied by Leaser America with the plates. The valves were labelled: Continental Model 1094. These valves broke easily, had small ports which plugged and were difficult to operate. These . -5- DUP050108969 valves were replaced In April 1976 with a new model valve also supplied by tenser America (no Identification markings). These valves were of polypropylene construction with enlarged ports and improved plug design. This eliminated the breakage and pluggage problems encountered with the phenolic valves. However, the new valves were slightly wider than the plates and were more difficult to seal adequately. Since the valves had to be removed each time the plate ports had to be cleared, leakage between the valves and the plates became increasingly severe. The problems with port pluggage and valve design were intensified by misalignment of the filter cloths. However, it Is unlikely that providing proper cloth alignment would eliminate the other two problems. Small amounts of pigment would still enter the ports due to occasional defective cloths and the high-pressure hosing procedure between batches. Therefore, solutions would have to be found for all three areas to improve the reliability of the press. JNB:mnm ate. --6-- DU P050108970 Fi i+er Pre s s EI e m e n P A rrcxng e m enP DUP050108971 DUP050108972 APPENDIX 3 ree vva.^y Valve Oper o^"V ion Page 9 DU P050108973 APPENDIX 4 Polypropylene Elements supplied for Press 25: 1 - 42" sq. connection plate, 1-3/16" thick, drilled and eounterbored. to match existing eyes in head easting, 2 - 2" LPS x 12" Ig. liner pipes complete with locknuts. . 1 - 42" sq. special adapter, 4" thick for conversion of two eyed to three eyed design 1 - 42" sq. head liner plate, 1-3/16" thick 1 - 42" sq. follower liner plate^1-3/16" thick 26 - 42" sq. #1 button plates, 1-3/16" thick 27 - 4.2" aq. #3 button plates, 1-3/16" thick 54 - 42" sq. frames, 2" thick 55- phenolic three way valves mounted to plates furnished with stainless steel lag screws and gaskets. All parts except the valres were SAL 70.32 gray polypropylene. Parts supplied per quotation, Lenser America August 4, 1975 - 10 DUP050108974 APPENDIX 5 t DUP050108975 F il+ e r CIo fh M iso.1 iq n m e n 'f DUP050108976 Appendix 7 E. I. DU PONT DE NEMOURS AND CO. Pigments Department ' ee: I.H.Dunn DC.Gero J.R.Goughnour Y/.T, Harrington J.A.Johnson R.F.Mitchell . H.G.Ricardo F.Scalice A.P.Smith W.S.Struve R & D File Pit Ass't Pressing NEWARK, NEW JERSEY FEBRUARY 17, 1977 T. R. BECKER Pigments - NEWARK PRESS 25 CONVERSION TO OPEN DISCHARGE At our January 24, 1977 meeting, it was agreed that Press 25 would be con verted to standard open discharge service. Discussions were held with A. Whitlock, the Lenser America representative, to determine the steps required. The attached Quotation B, February 9, 1977 covers their work for the conversion. The procedure calls for reversing the plate, plugging the current three-way valve and redrilling the plate as required, the new head and tail plates listed in the quotation are not required since after further discussion it was agreed that the existing head and tail plates could be reworked. Therefore the cost for the reworking and the required new parts would be approximately $1450. Also listed in the quotation is the cost for replacing the current welded-on handles with bolt-on handles. Although this would convert the press to what is now the standard handle design and make future handle repairs easier, the cost would be $2086. Since the existing handles are satisfactory, I would recommend having our Mechanical Department gradually replace the handles as they break rather than including this in the conversion work. The method of doing this will be covered in a later letter on the existing open discharge polypropylene presses. Possible use of the four inch thick adapter head was also discussed with the Lenser representative, This piece is of no foreseeable use at the Newark plant but could possibly be returned to Lenser America for some amount of credit. This option would have to be pursued by H. Ricardo with Lenser America. The following steps would need to be done for the conversion: Order new connection plate and liner pipes. These should be on hand before converting the press so that the necessary repiping can be done while the polypropylene is being reworked. - 13 - DUP050108977 Press 25 -2- February 17, 1977 Remove al.l existing polypropylene from the press. Clean the polypropylene elements well prior to shipping to Lenser America. 0 Ship the polypropylene to Lenser in Whippany, N.. J. 0 While the polypropylene is off the plant for reworking, remove excess piping from the press. A diagram of the recommended piping is attached. This should include a pressure gauge on the feed line to prevent problems from overpressurizing the press, To do the work listed# the press will need to toe out of service for a period of two to three weeks. Any costs due to this conversion should be charged to XQ9.02, the S.O. authorized for testiaB closed discharge filtration. I would recommend that X0902 then toe closed out and a new 3.0. authorized for future open discharge press replacements. A final Research KN report is toeing written for Closed Discharge Filter Press Testing, This will serve to summarize, and close out this work as an R&D project. A copy of the report will toe circulated to those receiving a copy of this letter. .S) ^ JOHN N. BimitNGHiM R&D DIVISION JND:mnm ate. - 14 DUP050108978 ^tiS'taaispKir.a gran E. I. DuPont de Nemours Co. Newark, NJ Attention: Mr. H. Ricardo Appendix-7 page 4 Feb. 9, 1977 QUOTATION B: TO COVER CONVERSION OF EXISTING 42" SQUARE PRESSLOAD OF POLYPROPYLENE PLATES AND FRAMES FROM THREE WAY VALVE OPEN AND CLOSED DELIVERY.SYSTEM TO OPEN DELIVERY BY USING LEVER HANDLE SPIGOT. 1 - NEW head plate, 1-3/16" thick, #1 button, complete with lever handle spigot------ -------- ----------- ------ $ 112.50 1 - NEW tail plate, 1-3/16" thick, #1 button, complete with lover handle spigot ---A------ ------------------------ ... 112.50 26 - #1 button pressure plates - iWorked. Operations required - reverse plate: A. Spin weld plug in existing port in existing three- way valve port. B. Drill new discharge port in bottom blank pad, C. Drill pilot holes for spigot and assemble spigot. Labor'..,.. $12,00 each ------<---------------------- *--*-- New lever handle spigot, $5.50 each -----------..........-- 312.00 143.00 27 - #3 button wash plates - reworked. Operations required - reverse plate: A. Spin weld plug in existing port in existing three- way valve port. B. Drill new discharge port in bottom blank pad. C. Drill pilot holes for spigot and assemble spigot. D. Spin weld plug in existing wash port and drill new wash port in opposite. Labor ...... $21.00 each ------------ ------------------- New lever handle spigot, $5.50 each ------ -- --- 567,00 148.50 54 - frames - no labor required --------------------------------------- -- ' Replace existing 4" thick adapter currently being used for three way system. 1 - new 42" square connection plate, 1" thick, drilled and counterbored for two 2" dia. pull thru liner pipes, 2 - new 2" x 12" long liner pipes conplete with O-rings and locknuts, $45 each --------------------. ------------------ 146.00 90.00 Total Sales Price -------------- ------------------------ -------------- ------- $1631.50 Additional if .installation of bolt-on handles is desired on all of the above: 26 - #1 button plates 27 ~ H3 button plates 54 - IIZ button l frames 107 pieces - labor $12.00 each------ -------- - -------------- - $1284.00 - 15 - DUP050108979 E. I. DuPont de Nemours 5 Co. Newark, NJ Attention: Mr. H. Ricardo Appendix 7 page 5 Feb. 9, 1977 214 molded polypropylene universal handles (2-bolt design as furnished on 36" pressload) complete With stainless steel lag screws and washers, $3.75 each ---------------------------- --------- Total Sales Price ----------- --------- --..........-- ---------- ------- 802.50 $2086.50 Terms: net 30 days f.o.b Whippany, NJ Delivery: one week after receipt of goods from you. . Very truly yours, LENSER AMERICA INC ALWrrsb Allan L, Whitlock - 16 - DUP050108980 3Stress 2 - FTxed Mecxd "Pipin r Ire ed Appendix 7 / -ixi- Wo.sK Eyl -1 I > UI i f7 E.-f-T/u<s.n r . .** i u "-O' i (' Xnsj^li re <3 ucx<je ^"Feed ecj crx . So!iA * ET^Ts-Vi"Rp'n^j, 4-o be re-kained <. o4bed 3 jETX('$4- ing '~Pip/nj, 4-o be renown/eA. DUP050108981 DISTRIBUTION 1. E, Gonick, Plgm.,Wilm./Newark Library 2. E. E. Jaffe, Pigm., Newport/Circulate and file 3. Newport Library 4. W. S. Struve/H. Matriek/Library 5. A. P>. Smith. 6. J. F. Higgins/J, Jackson/B. H. Perkins/Library 7. J. N. Birmingham $. J.R.Goughnour/T.R,Becker/F. Scalice 9. D. C. Gero/R. F. Mitchell/W. T. Karrington/J. A, Johnson 10. Newark Numerical File Code: 104.12 11. Newark Library * Central Report Index 12. Newark Library - Central Report Index 13. Extra l4. Extra 15. Extra Security - None \l DU P050108982 E. I. DU PONT DE NEE/OURS AND CO Pigments Department KN 77-6 ISSUED - 10/24/77 COW No. / ) NEWARK PLANT PIGMBT COLORS RESEARCH AND DEVELOPMENT REPORT TITLE EVALUATION OF ENCLOSED DISCHARGE FILTER PRESS TO REDUCE ARM FOGGING FINAL REPORT Work Done By John N, Birmingham Report Written by John N. Birmingham Project Code 4656-700 Period Covered: January 1976 - February 1977, part time ABSTRACT During periods of cold weather, warm press effluent in the batch processing; area causes excessive steam generation* This results in a hazardous work environment and inefficient use of the area. A filter press was installed which by means of valves on the plates and a third eye in the plates and frames provided enclosed discharge of the effluent. It was planned that by use of enclosed effluent discharge, steam generat ion would be markedly reduced. This type of filter press was not suitable for Newark plant operation. Difficulties included filter cloth alignment, effluent line pluggage and inadequately designed valves. Although solutions to most of the problems appear possible, the effort required would not be justified. Furthermore, sustained operation of the press would still be difficult for Manufacturing. DU P050108983 t abl e o p c o nt ent s INTRODUCTION OBJECTIVE SUMMARY AND CONCLUSIONS PROGRAM DISCUSSION APPENDICES 1 2 3 ll 5 6 7 Page 1 1 I 2 2 7 8 9 10 11 12 13 -17 DUP050108984 INTRODUCTION: Batch manufacturing at Newark includes dewatering and washing of pigment slurries using plate and frame filter presses. Many of these slurries are warm when filtered, in some cases having temperatures as high as 190F. The filter presses have individual effluent lines from the plates, all of which discharge to the floor drains. During periods of cold weather, roughly October through March, the warm press effluent causes excessive steam generation in the work areas. This creates a hazardous condition due to limited visability and prevents optimum utilization of other equipment in the. area. Study of the problem has shown that most of the steam is caused by the hot effluent flowing over the cold floors in the work areas. Steam is formed due to the low temperature of the floor and the immediate air. The amount of steam is increased due to the wide floor area over which the effluent is allowed to flow. OBJECTIVE: . Evaluate the operability of a filter press capable of both open and enclosed discharge of effluent. Using the enclosed discharge process, determine the impact of efficient effluent removal on steam generation. SUMMARY AND CONCLUSIONS: A filter press was installed which combined three-way valves on the plates with a third eye in the plates and frames. This enabled the press to be operated either as a standard open discharge press or as an enclosed effluent discharge press. This type of filter press was not suitable for Newark plant operation. Major problems occurred in the following areas; Filter cloth alignment. Misalignment of the filter cloths frequently resulted in pigment being forced into the effluent eye of the press. This resulted in yield loss and pluggages. -1- DUP050108985  Effluent line pluggage. The small diameter effluent lines in the plates often plugged. This reduced the filling and washing efficiencies of the press and required periodic service outages for cleaning. 0 Plate valve design. Both valve designs tested presented operating and maintenance difficulties. Although solutions to most of these problems appear possiblej the technical effort required would be excessive. Fur thermore , sustained operation of the press would still be difficult for Manufacturing. Therefore, the press is to be reworked to operate as a standard open discharge filter press. Due to the poor operability of the press, the effect of closed discharge effluent removal was not evaluated. PROGRAM: This report will serve to close out R & D work on a filter press capable of both Open and enclosed discharge of effluent. It was agreed with Manufacturing that the press would be reworked to standard open discharge service. Recommendations and information have been supplied to Manufacturing on the work required for con version (Itr. JNB - TRB, 2/17/77 - Appendix 7). R & D will reactivate the trough project originally studied. Work on troughs was deferred during testing of the enclosed discharge press. The trough project is also based on achieving efficient removal of the warm effluent to reduce steam generation, DISCUSSIOM: During January 1976, press 25 was modified to be capable of both open and enclosed discharge of effluent. To do this, polypropylene plates and frames Incorporating a third eye for - 2- DUP050108986 effluent removal were Installed. A special four inch thick adapter slab was fabricated with a side discharge fitting. This enabled three-eye operation in a press originally constructed for two-eye service. The element arrangement is shown in Appendix 1. The plates were ported and equipped with three-way valves to provide both open and enclosed discharge. The porting and method of valve operation are shown in Appendices 2 and 3. All required polypropy lene material was purchased from Lenser America, Inc., Whippany, N. J. as per Appendix 4. Use of polypropylene plates and frames required alteration of the press closure device. The press is closed and sealed by means of a hydraulic ram. When used with the previous iron elements, the press was sealed by the hydraulic ram to 1200 psig hydraulic pressure. At that point, a lock nut on the ram was secured and the hydraulic system was turned off. During operation, the ram was locked in a stationary position and the hydraulic system was not energized. Due to the relatively high thermal expansion of poly propylene* this system was not usable. When filling with hot slurry, the press length would expand and increase the stress on the press skeleton. This could result in permanent damage to the skeleton. Upon switching to cold water washing, the press length would contract and lower the clamping pressure. This could result in leakage throughout the press. The ram hydraulic system designed for the polypropylene filter press is illustrated in Appendix 5. The lock nut was removed to prevent securing the ram in a fixed position. Valves and a pressure switch were installed in the hydraulic lines. During operation, the control switch is left on and the pressure switch controls the pump. The low (1050 psig) limit on the switch restarts the pump, thereby preventing underpressurizing the press. When hydraulic pressure reaches 1200 psig, the switch shuts off the pump. If pressure continues to increase due to thermal expansion, the relief valve limits the maximum pressure at 1300 psig. This prevents dangers due to over-pressurizing the press. The system worked well during the year of operation and is being used on all other polypropylene press conversions. -3- DUP050108987 During operation, three main areas of difficulty were encountered: filter cloth alignment, port pluggage and valve design. Filter cloths were misaligned primarily because of inaccurately cut filter cloths and poor accessibility of the efflu ent eye- Filter cloths are cut from bulk material on the plant. Due to the limited facilities available for this work, location of cut eyes on the cloths is erratic. This type of error is marginally acceptable with the two eye presses now used. However, with a third eye in the lower corner of the press, alignment of the upper two eyes often results in the third eye being off center. The problem is compounded by the location of the third eye. These eyes are on a level with the platform upon which the operators are standing. Therefore, in aligning the upper two eyes, the misalignment of the lower eye can pass unnoticed. The result of filter cloth misalignment is illustrated in Appendix 6. The error in the cloth eye position was always above and normally toward the center of the desired spot. This reduced the gasket area of the cloth which separates the frame chamber from the effluent eye. As the slurry pressure increased during the fill Cycle, pigment could be forced past the reduced gasket area into the effluent line. This resulted in product loss and pluggage of effluent lines. Pigment could also be forced through to the plate filter area, resulting in bleeds throughout the press. An attempt was made to correct this problem by gluing the filter cloths to the press. A mastic produced by 3M was used to secure the two layers of filter cloth together and to the polypropylene plate. The mastic performed well and prevented misalignment. However, several difficulties exist. The gluing operation is time and labor intens ive. Based on the time required by R & D during the test, 24 hours by two men would be required to secure an entire press. This would be required approximately once every two months. During regular operation, individual defective cloths are replaced during the unloading of the press between batches. This would be difficult using the gluing procedure. Further, the problem of miscut filter cloths would still exist. ~4 DU P050108988 A possible solution which was not evaluated is the use of precut cloths supplied by an outside vendor* Use of ties on the out side edges would prevent cloth misalignment. This was not pursued due to Manufacturing concern over increasing tramp material into the product. The second major area of difficulty was pluggage of the plate ports. Causes of the pluggage were pigment entering the lines and the design of the lines in the plate. Pigment could enter the lines due to either the cloth misalignment discussed earlier or occassional bleeds through defective cloths. Since this press was used in "KROLOR" service, hardened chips of silica and pigment from the strike vat also occasionally got into the lines. The design of the lines also promoted pluggage. As shown in Appendix 2, the lines were 1/8" diameter and the line going from the plate grid area to the valve includes a 105 degree turn. Due to the causes discussed, all valves on the press gradually plugged, in some cases completely stopping flow through a particular plate. This lengthened the fill time and reduced press washing efficiency by limiting the maximum flow through the press. To correct the pluggage, the press had to be taken out of service periodically, its valves removed and the lines cleared with a high pressure water Jet. A possible solution to this problem would be to enlarge the diameter of the ports and to machine a cavity where the 105 degree turn occurs. The cavity would modify the effect of the sharp turn between the two port lines. However, this solution would require extensive reworking of the plates. Also, enlarged line diameter would weaken the plate. The final area of difficulty was the three-way valve used on the plates. The original valve tested was black phenolic model supplied by Lenser America with the plates. The valves were labelled: Continental Model 1094. These valves broke easily, had small ports which plugged and were difficult to operate. These -5- DUP050108989 valves were replaced in April 1976 with a new model valve also supplied by Lenser America (no identification markings). These valves were of polypropylene construction with enlarged ports and improved plug design. This eliminated the breakage and pluggage problems encountered with the phenolic valves. However, the new valves were slightly wider than the plates and were more difficult to seal adequately. Since the valves had to be removed each time the plate ports had to be cleared, leakage between the valves and the plates became increasingly severe. The problems with port pluggage and valve design were intensified by misalignment of the filter cloths. However, it is unlikely that providing proper cloth alignment would eliminate the other two problems. Small amounts of pigment would still enter the ports due to occasional defective cloths and the high-pressure hosing procedure between batches. Therefore, solutions would have to be found for all three areas to improve the reliability of the press. JNB:mnm ate. -6 - DUP050108990 . APPENDIX 1 DUP050108991 APPENDIX 2 D U P re s s 2 .5 Piov+e P r*f DUP050108992 1 APPENDIX 3 ree. Wa.y Vcxlve. Otd e r <x+ \ OTA m A 5 page 9 DUP050108993 APPENDIX 4 Polypropylene Elements supplied for Press 25* 1 - 42" sq, connection plate, 1-3/16" thick, drilled and eounterbored to match existing eyes in head casting. 2 - 2" LPS x 12" lg. liner pipes complete with locknuts. 1 - 42" sq. special adapter, 4" thick for conversion of two eyed to three eyed design 1 - 42" sq. head liner plate, 1-3/16" thick 1 - 42" sq. follower liner plat e^&1-3/16" thick 26 - 42" sq, #1 button plates, 1-3/16" thick 27 - 42" aq. #3 button plates. 1-3/16" thick 54 - 42" sq, frames, 2" thick 55- phenolic three way valves mounted to plates furnished with stainless steel lag screws and gaskets. All parts except the valres were RAL 7032 gray polypropylene. Parts supplied per quotation, Denser America August 4, 1975* - 10 - DUP050108994 APPENDIX 5 q; DX <S) L. Q) "0 C ^T> r~ +D. DUP050108995 APPENDIX 6 6 QJ A- <- DUP050108996 E. I. DU PONT DE NEMOURS AND CO, Pigments Department Appendix 7 cc: I.H.Dunn D,C.Gero J.R.Goughnour W.T.Harrington J.A.Johnson R.F.Mitchell H.G.Ricardo F.Scalice A.P.Smith V/.S. Struve R & D File Pit Ass't Pressing NEWARK, NEW JERSEY FEBRUARY 17, 1977 T. R. BECKER Pigments - NEWARK PRESS 25 , CONVERSION TO OPEN DISCHARGE At our January 24, 1977 meeting, it was agreed that Press 25 would he con verted to standard open discharge service. Discussions were held with A.Whitlock, the Lenser America representative, to determine the steps required. The attached Quotation B, February 9, 1977 covers their work for the conversion. The procedure calls for reversing the plate, plugging the current three-way valve and redrilling the plate as required. The new head and tail plates listed in the quotation are not required since after further discussion it was agreed that the existing head and tail plates could be reworked. Therefore the cost for the reworking and the required new parts would be approximately $1450. Also listed in the quotation is the cost for replacing the current welded-on handles with bolt-on handles. Although this would convert the press to what is now the standard handle design and make future handle repairs easier, the cost would be $2086. Since the existing handles are satisfactory, I would recommend having our Mechanical Department gradually replace the handles as they break rather than including this in the conversion work. The method of doing this will be covered in a later letter on the existing open discharge polypropylene presses. Possible use of the four inch thick adapter head was also discussed with the Lenser representative. This piece is of no foreseeable use at the Newark plant but could possibly be returned to Lenser America for some amount of credit. This option would have to be pursued by H. Ricardo with Lenser America. The following steps would need to be done for the conversion: Order new connection plate and liner pipes. These should he on hand before converting the press so that the necessary repiping can be done while the polypropylene is being reworked. - 13 - DUP050108997 Press 25 -2- February 17, 1977 Remove all existing polypropylene from the press. . Clean the polypropylene elements well prior to shipping to Lenser America. Ship the polypropylene to Lenser in Ihippany, U, 3, 0 While the polypropylene is off the plant for reworking, remove excess piping from the press. A diagram of the recommended piping is attached. This should include a pressure gauge on the feed line to prevent problems from overpressurizing the press. To do the work listed, the press will need to be out of service for a period of two to three weeks. Any costs due to this conversion should he charged to X0902, the S.O. authorized for testidft closed discharge filtration. I would recommend that XD9D2 then be closed out and a new S.O. authorized for future open discharge press replacements. A final Research KN report is being written for Closed Discharge Filter Press Testing. This will serve to summarize and close out this work as an R&D project. A copy of the report will he circulated to those receiving a copy of this letter. JNBsmnm ate. JOHN N. BimONGHi&f R & D DIVISION DUP050108998