Astley, Vaughn

English

Engineering Conferences International

Engineering Conferences InternationalECI Digital ArchivesBeneficiation of Phosphates VII ProceedingsSpring 2015The Use of a Advanced Process Controls in aPhosphoric Acid ReactorVaughn AstleyFollow this and additional works at: http://dc.engconfintl.org/phosphates_viiPart of the Materials Science and Engineering CommonsThis Conference Proceeding is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion inBeneficiation of Phosphates VII by an authorized administrator of ECI Digital Archives. For more information, please contact franco@bepress.com.Recommended CitationVaughn Astley, "The Use of a Advanced Process Controls in a Phosphoric Acid Reactor" in "Beneficiation of Phosphates VII", P.Zhang, FIPR; J. Miller, Univ. of Utah; L. Leal, Univ. of Sao Paolo; A. Kossir, OCP Group; E. Wingate, Worley-Parsons Services PtyLtd. Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/phosphates_vii/23Vaughn Astley  Beneficiation of Phosphates VII Melbourne, Australia  29th  March to 3rd April, 2015 The Use of  ADVANCED PROCESS CONTROLS in a Phosphoric Acid Reactor Remember, Remember when Automobiles/Cars has just a Steering Wheel, Gearlever, and Three Pedals???  Maybe a Direction Indicator Stalk, Maybe Windscreen Wipers Too!!!  Independent Rear Suspension, WOW!!! Now we have…………. ADVANCED PROCESS CONTROLS (APC)  4EAT ABS  ACE  ACC  ADAS AGVS ARC  ASR  ASTC ATTS AYC  CVRSS DMCM DSCC  EAS EBCM EBD  EBTCM ECD  ECM EDR  EGRCMDS  EHCU EHPAS EMAS ETS  EVTOP FEDS HICUS ICC  ICWS IEDIS LDAS NAICC TCS  VSES WVVWS  Who Knows What These Do?          APC 4EAT 4 Speed Electronic Automatic Transmission ECD  Electronically Controlled Deceleration ABS Antilock Brake System   ECM Engine Control Module  ACE Active Cornering Enhancement  EDR Event Data Recorder ACC Adaptive Cruise Control  EHCU Electronic Hydraulic Control Unit ADAS Advanced Driver Assistance System EHPAS Electric Hydraulic Power Assisted Steering AGVS Automated Guided Vehicle System  EMAS Engine Management and Analysis System ARC Active Roll Control   ETS Enhanced Traction System  ASR Acceleration Slip Regulation  EVTOP Enhanced Tactical Vehicle Occupant         Protection      EGRCMDS   EGR Motor Commanded In Steps ASTC Automatic Stability and Traction Control FEDS Flexible Engine Diagnostic System ATTS Advanced Torque Transfer System  HICAS High Capacity Actively Controlled Steering AYC Active Yaw Control   ICC Intelligent Cruise Control CVRSS Continuous Variable Road Sensing Suspension ICWS Intersection Collision Warning System DMCM Driver  Motor Control Module  IEDIS Integrated Electronic Distributorless Ignition System DSCC Distance Sensing Cruise Control  LDAS Lane Departure Avoidance System EAS Electrically Assisted Steering  NAICC Navigation-Aided Intelligent Cruise Control EBCM Electronic Brake Control Module  TCS Traction Control System EBD Electronic Brake force Distribution  VSES Vehicle Stability Enhancement System EBTCM Electronic Brake Traction Control Module WVVWS Wireless Vehicle to Vehicle Warning System       APC WOW!!! All These Computer Controls from the Cars Sensors!! Improved Fuel Economy! More Power From Smaller Engines! Less Emissions!! FASTER ACCELERATION!!! More Stability  FASTER AROUND CORNERS!!! Latest BMW has about 90 Computer Control Devices Nearly All are Passive to Driver!!!!  APC Continuously Controls Sulphate, P2O5 Strength and Operating Rate of PhosAcid Plants….. PhosAcid Cruise Control!!!!! – Development History – How it Works – How it Performs – Benefits – How it is Installed APC  History of  Original Development and Implementation – 1980’s, IMC & Agrico Advisory Programs for Sulphate Control – Took ~2 Years to get the Sulphate Control to Perform, – Took ~4 years to get the P2O5 Gravity and Filter Feed Controls to an Acceptable Operational Status. – On-Line Control System for Sulphate, Rate and Strength Control Implemented by IMC in 1991 at Three New Wales Plants  Installed at South Pierce, Faustina, and Uncle Sam after Merger with Agrico in 1993  Partial Installation at Riverview and Bartow After Merger with Cargill to Form Mosaic in 2004 APC  Current  Development and Implementation – Improved Program and Logic Codes Written From Scratch and Operator/Supervisor/DCS Interaction Improved in 2006 – Wash Water Pulse Eliminated  Many Inquiries, but Installed at Only One Other Plant. APC APC SO HOW DOES IT WORK!!!! Sulphate Control Phosphoric Acid Strength Control Filter Feed Control Filter Feed Level Control By ………….Finally Controlling Rock Rate   APC Attack Filter Filter Wash Water Filtrate Acid Sulphuric Acid Rock Recycle Acid Filter Feed Calcium  Sulphate  Sluice Water? Bypass Water PHOSPHORIC ACID FLOWSHEET APC Sulphate Control –Measure Sulphate in PhosAcid each Hour (Flexible) –Targeted Sulphate Level is Set (performance) –Acid to Rock Ratio Adjusted to Attain Target –Ratio Adjusted After Sulphate Sample Result Entered –Corrects Each Time Based Upon How Previous Adjustments Performed!!!! APC Attack Filter Filter Wash Water Filtrate Acid Sulphuric Acid Rock Recycle Acid Filter Feed Calcium  Sulphate Sluice Water? Bypass Water PHOSPHORIC ACID FLOWSHEET APC 1.522.530 10 20 30BC (Before Computers) SO4 Control Target    ??? Act Avg  2.20 Std Dev  0.36 March, 1988 Wt %  SO4 1.522.5310 20 30Target    2.00 Act Avg  2.00 Std Dev  0.12 On-Line SO4 Control November, 1990 SO4 Standard Deviation Before APC Advisory On-Line Full Cascade SO4 Standard Deviation More recent 2007 - 2010 Data 0.400 0.146 0.139 0.119 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450 July 21, 2004-Sept 30, 2007 August 26, 2009-Jan 20, 2010 As Is With Control Program August 26, 2009-Jan 20, 2010 With Latest Adjustments Feb 1, 2010-March 23, 2010 With Latest Adjustments Average Free Sulfate Difference from Target Partial Cascade Sulphate Control…………………………...Done Next We add:- Phosphoric Acid Strength Control –P2O5 target…Based on Downstream Needs –Continuously Monitors Water to Rock Ratio –Adjusts Filter Wash Water –Controls By-Pass Water –Adjust Ratio After Every Sample, (Hourly) –Corrects Each Time Based Upon How Last Adjustments Performed!!!!  APC Attack Filter Filter Wash Water Filtrate Acid Sulphuric Acid Rock Recycle Acid Filter Feed Calcium  Sulphate Sluice Water? Bypass Water PHOSPHORIC ACID FLOWSHEET APC 262728293010 20 30January, 1990 Target    28.20 Actual    28.13 Std Dev   0.53 Wt % P2O5 BC (Before Computers) P2O5 Control 31 Days of January, 1990 Target    28.20 Actual    28.13 Std Dev   0.53 BC (Before Computers) P2O5 Control 262728293010 20Target    28.38 Actual    28.38 Std Dev   0.32 January, 1993 Wt % P2O5 On-Line P2O5 Control Target    28.38 Actual    28.38 Std Dev   0.32  Was        0.53 30 Days of November, 1993 On-Line P2O5 Control Sulphate Control  ……………………...…..Done Phosphoric Acid Strength Control….…..Done Next We Add:- Filter Feed Control – Tail Wash Filtrate Density Needed APC Attack Filter Filter Wash Water Filtrate Acid Sulphuric Acid Rock Recycle Acid Filter Feed Calcium  Sulphate Sluice Water? Bypass Water PHOSPHORIC ACID FLOWSHEET density APC PHOSPHORIC ACID PLANT ON-LINE CONTROLS Sulphate Control  …………………….. …..Done Phosphoric Acid Strength Control….…..Done Filter Feed Control – No. 3 Filtrate Density Target – Density Target Sets Filtration Recovery – Filter Feed Rate Set is Based on Final Filtrate Density  One Attack….. Three Filters!!!!! Sulphate Control  ……………………...…..Done Phosphoric Acid Strength Control….…..Done Filter Feed Control Finally We Add:- Rock Rate –Rock Rate Set is Simply Based on the Filter Feed Level   APC Attack Filter Filter Wash Water Filtrate Acid Sulphuric Acid Rock Recycle Acid Filter Feed Calcium  Sulphate Sluice Water? Bypass Water PHOSPHORIC ACID FLOWSHEET Level density APC  Initially Sulphate Control was the Focus for First Two or Three Years.  The Next Several years were Needed to Optimize the Programs Used to Control the More Complex P2O5 Attack Gravity.  Finally, Again Three or so Years Needed for the Slurry Filter Feed and Filter Operation to be Perfected.    So What Happened?? APC How it Performed APC P2O5 Recovery vs Time-4.00-2.000.002.004.006.008.00JAN, 84JAN, 85JAN, 86JAN, 87JAN, 88JAN, 89JAN, 90JAN, 91JAN, 92JAN, 93JAN, 94%P2O5 Recovery Change Monthly 5 Month Rolling Avg Add Automatic Controls P2O5 Recovery vs Time-4.00-2.000.002.004.006.008.00JAN, 84JAN, 85JAN, 86JAN, 87JAN, 88JAN, 89JAN, 90JAN, 91JAN, 92JAN, 93JAN, 94%P2O5 Recovery Change Monthly 5 Month Rolling Avg Add Automatic Controls P2O5 Recovery vs Time-4.00-2.000.002.004.006.008.00JAN, 84JAN, 85JAN, 86JAN, 87JAN, 88JAN, 89JAN, 90JAN, 91JAN, 92JAN, 93JAN, 94%P2O5 Recovery Change Monthly 5 Month Rolling Avg Add More Controls Add Automatic Controls P2O5 Recovery vs Time-4.00-2.000.002.004.006.008.00JAN, 84JAN, 85JAN, 86JAN, 87JAN, 88JAN, 89JAN, 90JAN, 91JAN, 92JAN, 93JAN, 94%P2O5 Recovery Change Monthly 5 Month Rolling Avg Add Automatic Controls Add More Controls H2SO4/P2O5 vs CaO/P2O51.421.441.461.481.51.52CaO/P2O5 2.552.652.752.85H2SO4/P2O5CaO/P2O5 H2SO4/P2O5 Make Changes 0 +0.1 -0.1 -0.2 AVERAGE DAILY PRODUCTION-15-10-5051015202530% PRODUCTION CHANGEMonthly 5 Month Rolling Avg Make Changes . Average Daily Production % Production Change  5 Month Rolling Average                     -5 -10 -15 AVERAGE DAILY PRODUCTION-15-10-5051015202530% PRODUCTION CHANGEMonthly 5 Month Rolling Avg Make Changes . Average Daily Production % Production Change  5 Month Rolling Average                  0   -5 -10 -15  Did the On Line Controls Give an Improvement of about 0.5% or 7%?  It Did Both  The Reduction in Water Soluble/Citrate Soluble Losses in the Gypsum was About 0.75%  However, Other Losses Also Decreased – Flash Cooler Losses – Less Upsets on Filter and Filterability – Line Scrub Losses (Less Build Up, Steadier Super-Saturation levels) – Less Filter Scaling  ( Ditto ) – Tank Clean Out Losses – Less Frequent Down Days  A Smoother Operation Leads to Many Improvements Downstream  APC  In Early On Line Control System Implementations – The Reduction in Filter Losses After the Implementation of On-Line Controls was About 0.5 - 1% – (But at a Higher Rate and With an Inferior Rock Quality) – But the Improvement in the Overall Recovery for the PhosAcid Facility was Over 7%  Results Will Depend on How Well Current Facility is Operated!!! APC  How It All Links Together….. APC The PhosAcid Control Strategies No. 3 Filtrate Density Target Sulphate Target Filter Feed Sulphate    P2O5  Strength Rock Rate Filter  Feed H2SO4   Rock Filter Wash Water     P2O5 Target Bypass Water Filter Feed Level The PhosAcid Control Strategies No. 3 Filtrate Density Target Sulphate Target Filter Feed Sulphate    P2O5  Strength Rock Rate Filter  Feed H2SO4   Rock Filter Wash Water     P2O5 Target Bypass Water Filter Feed Level The PhosAcid Control Strategies No. 3 Filtrate Density Target Sulphate Target Filter Feed Sulphate    P2O5  Strength Rock Rate Filter  Feed H2SO4   Rock Filter Wash Water     P2O5 Target Bypass Water Filter Feed Level The PhosAcid Control Strategies No. 3 Filtrate Density Target Sulphate Target Filter Feed Sulphate    P2O5  Strength Rock Rate Filter  Feed H2SO4   Rock Filter Wash Water     P2O5 Target Bypass Water Filter Feed Level PHOSPHORIC ACID PLANT ON-LINE CONTROLS Control Limits and Logic (Some Fuzzy) for  –Multiple Filters and Flow Partitioning –Upset Conditions –Data Entry Errors –Rate and Flow Limits –Adaptive In That Drift In Instrumentation Has Little Effect –Use of Data to Enhance Operations  Large Rate Improvements  Increased Reactor/Filter Rates – Higher Average Operating Rates   Increased Operating Time Due to: – Less Frequent Filter Scrubs – Longer Times Between Turn-Rounds – Less Line Scaling .  Characteristics of Currently Operating Control Systems – Use Look-Up Charts… – Bump and Step Charts,  – Tables of Adjustments – Simple Programs.. Enter SO4 Deviation and Rock Rate, Tells Operator How to Change Sulphuric Acid. – What-If diagrams.  – Need Constant Attention of Operator – Wouldn’t Cruise Control be Better? – i.e. Even Stability Control!!  How Are Other Attacks Controlled Now? How it is Installed APC SO HOW TO CATCH UP!!!  What we do…………..  Two Week Site Visit, Evaluation of Plant Performance, Lab Data, and Analysis of Electronic DCS Data,  Need 3 to 6 months of 1 Minute DCS and All Laboratory Loss Data, (250,000 rows!!!)  We Estimate Benefit to Recovery and Production,  We Determine Cost of Full APC Installation, Including Training,   About $34K ( Intn’l) to Accomplish This First Step  THEN, if Acceptable, Implement Full APC   Is Control too Complicated and Costly to Install and Maintain?  – (Turn-Key…  ~$400,000 to Install for Domestic, ~$500,000 for International Facilities and <$5,000/Yr to Maintain) – Similar Trains are ~$100K Each   Do We Need On-Line Analysis  – You Don’t need Continuous Analysis, Just The Routine Hourly Sulphate and Gravities is All that is Needed!!!  APC Implementation Of Full APC  Site Visits to Observe Operations and Collect Data.  A Year or Two of Electronic ( 1 Min DCS Data), & Lab Data to Develop Computer Control Programs  DCS Programming with Operational Code  Operator Training and Debugging  Several Site Visits for Installation and Training  Stepwise Commissioning, and Operator Training in:-  – Free SO4 Operation & Control, – Target P2O5 Strength Control, – Filter Feed and Multi-Filter Operation,  – Finally Level Control & Rock Feed. Total Installation Cost Say About $450K   A 1% Recovery Improvement at 4000 tpd P2O5 is 40 tpd A 2% Production Improvement at 4000 tpd P2O5 is 80 tpd  At Roughly $350/ ton P2O5 @ 120tpd is thus $40,000 per day!! About a 12 Day payback!! If you are @ 1200 tpd P2O5 then about a Month!!! Implementation Of Full APC SMOOOOOOOTH Running!!  Poor Operation, $980,000 pa. Higher Losses $750,000 pa. Upsets, Plant Crashes, $850,000 pa. Higher Scaling Costs, $350,000 pa Operator Mistakes $699,997.7 pa. Good Control….Priceless (MasterCard Ad)  Thank You   VaughnAstley@DrPhosphate.com   A Set of Notes in French are shown in “notes’ view Des commentaires en langue Française de la présente présentation y sont incluses  

The Use of a Advanced Process Controls in a Phosphoric Acid Reactor

https://dc.engconfintl.org/cgi/viewcontent.cgi?article=1000&amp;context=phosphates_vii

The Use of a Advanced Process Controls in a Phosphoric Acid Reactor

Abstract

Similar works

Full text

Available Versions

Engineering Conferences International