The Screening, Dewatering and Drying Experts Centrifuge and Belt Press Maintenance Previous Slide
Introduction Brian Lent Western Regional Aftermarket Sales Manager Experience 1976 1981 BIRD MACHINE Walpole MA Based out of Boston MA 1981 1998 Humboldt Decanter -Norcross GA Based out of San Ramon CA 1998 2006 BAKER PROCESS Walpole MA (Formerly BIRD) Based out of San Ramon CA 2006 to Present Andritz Separation Inc Arlington TX Based out of San Ramon CA 2
Belt Press Centrifuge 3 Individual footer (e.g. title of presentation, date, name of presenter): Arial 9 pt, gray, align center, max. 1 line
Dewatering Equipment like and other processing devices have there limits Centrifuge and Belt Presses both have a solids loading and a liquid loading limit Belt Press units have a basic rule of thumb 100 gpm per meter of belt width 1000 #/hr per meter of belt width 4 Individual footer (e.g. title of presentation, date, name of presenter): Arial 9 pt, gray, align center, max. 1 line
Centrifuges Centrifuges are sized by the Optimal capacity of the bowl configuration and volume that can be put through it at that optimum loading The solids loading is dependent on the feed solids THE HIGHER THE FEED SOLIDS THE LOWER THE FLOW to maintain the optimal performance The liquid loading is also dependent on the feed solids THE THINNER THE FEED THE HIGHER THE FLOW RATE to maintain the optimal performance This is why in the market most companies have sizes that have similar sizes and geometry The newer designs are pushing that curve to it s limits When these loadings are exceeded the optimal performance of these machines suffers drastically loss of % cake solids and flow through put 5
How to calculate Throughput Known: Flow Rate Feed Solids Specific Gravity of Feed Slurry (use 1.0 if unknown) T = FR x 8.345 lbs/h x 60 minutes/h x FS% x SG SL or simplified T = 5 x FR x FS x SG SL T --- Throughput in lbs/hr Dry Solids FR --- Flow Rate in Gallons per Minute FS --- Feed Solids in % Dry Solids SG SL --- Specific Gravity of sludge or slurry (use 1.0 for municipal sludge) Example: Flow Rate = 100 GPM Feed Solids = 2.5 % DS SG Sludge = 1.0 Throughput = 1,250 lbs/h DS Andritz Separation Inc. Slide No. 6
SLUDGE FROM TYPICAL WASTEWATER TREATMENT Andritz Separation Inc. Slide No. 7
From the simple sketch you can see that sludge is made up of waste and that waste has the kitchen sink in it. The wastewater treatment plants try to remove the heavy particulate and screen most of the plastic and grit but a large amount still manages to get to the solids handling end of the plant where it is dewatered. Contrary to popular thought not all Poop is the same each sludge has its own characteristics, chemical make up, grit levels, ash content, settling rates and any other individual id component one can think of. With that thought how do we protect our equipment Protected and coated frames Most Belt Press units have Protected bearings and sealed housings Protected rollers Stainless steel fasteners and fittings Plastic and protective housings and covers Gear boxes and drives 8 Individual footer (e.g. title of presentation, date, name of presenter): Arial 9 pt, gray, align center, max. 1 line
Having said this EVERYTHING REQUIRES SOME DEGREE OF MAINTENANCE The normal wear items for a Belt Press are The Belts normal wear is 2000 to 3000 hours but this depends on the grit and pressure applied to the rollers The Rollers the rollers have an normal life expectancy of 10 years again depending di on the grit and pressures applied Tracking and tensioning systems (either pneumatic or hydraulic) have a life cycle also there life is dependent on the pressure, operating cycles and general lhousekeeping of fthe unit Drives / gear boxes there life cycle depends on lubrication changes, alignment and general housekeeping Bearings and seals these are the only items that require constant attention as far a grease and housekeeping The frame and ancillary equipment requires attention when it fails or is damaged 9
Belt press lubrication 5.3.1 Lubricant Specification REFERENCE SYMBOLMOBILSHELLTEXACO A - GreaseMobilith SHC 460- - - -- --- B - OilMobilgear 630Shell Omala Oil 220Meropa 220C - GreaseMobilux EP2Shell Alvania Grease R3Multifak EP2 5.3.2 Lubrication Schedule Frequency Lubricant 1. Grease bearings monthly A 2. Grease tracking device 1 month A 3. Grease thrust rods on tensioning device 6 months A 4. Check oil level in drive gearbox 80 hours B 5. Change oil in drive gearbox 10,000000 hours (2 years) B 6. Repack bearings in drive gearbox 20,000 hours (4 years) C 7. Grease bull gear & drive pinion gear 1 month A 5.3.3 Lubrication Location *Graphics may differ from actual machine* All equipment should have a simple grease chart that can be followed It is up to the customer to log these lubrication events 10
Centrifuges have similar il wear and maintenance points Most centrifuges in the market these days are outfitted with the following standards Bowls, bowl heads, conveyors and hard components are 316 SS or made from a casting type duplex Stainless Steel The feed compartments, feed ports, cake ports and conveyor tips are protected or made from a Tungsten Carbide or similar material Most have SS liners or covers protecting the solids and liquids discharge points Most have bearings are designed for L10 ratings and the seals are Buna or better depending on service Most bases are carbons steel with powder coating or epoxy coatings 11
Centrifuge Maintenance Requirements 5.3.1 Lubricant Specification LUBRICANT LIST LUBE TYPE SKF Mobil Shell BP Centrifuge A. Grease SKF LGMT2 Mobilux EP2 Alvania EP2 Energrease LS EP2 B. Grease SKF LGMT3 Technology Quality Innovative Reliability High Performance C. Grease EXCLUSIVELY Energrease PR EP 00 D. Oil Mobil SHC X100 30 BP Super visco static 627 20w50 5.3.2 Lubrication Schedule Frequency Lubricant Quantity 1. Grease bearing - feed end 200 hours A 20 Gr 2. Grease bearing - drive end 200 hours A 15 Gr 3. Grease thrust bearing - feed end 4000 hours B 100 Gr 4. Change grease in drive speed inducer 4000 hours C 3000 Gr 5. & 6. Grease electric motor bearings 3000 hours A see Vendor info 5.3.3 Lubrication Location
Maintenance Service Intervals Most suppliers have a standard chart that is used as a guide for the customers to logically project the maintenance of a particular size centrifuge (the parts cost and labor vary by size) but they all have a specific repair interval. These type of charts can be used as guides for projected maintenance costs. The frequency of the intervals is dependent on the operating hours per day, week and year. The first few years of a 4000 operating hour centrifuge is obviously less than a unit that is in service 24/7/365 unit 13
Andritz Centrifuge Features 12. Centrifuge Maintenance Requirements DESCRIPTION 200 HRS 3000 HRS 4000 HRS 6000 HRS 8000 HRS 9000 HRS 12000 HRS 15000 HRS 18000 HRS 24000 HRS 1. * Lubricate both support bearings EVERY 200 hrs X 2. Renew grease in cyclo & thrust brg. X X X X X X 3. General inspection X X X X X 4. Inspect scrapers, deflector rings (D7L only) X X X X X 5. Inspection of drive belts X X X X 6. Mechanical inspect of feed brg. block X X 7. Inspection of nozzles X X 8. Renew grease in REDEX pulley after 1 st 200 hrs X X X X X X X X 9. Inspection of bearings & seals X X 10. Inspect / dismantle of reducer X X 11. Inspect / overhaul of torque limiter X X 12. Inspect deflector X X 13. Inspect feed & discharge ports ( where applicable) X X X X X 14. Inspect drive belt tension X X 15. Inspect vibration isolators (shock absorbers) X 16. Inspect elastic coupling X 17. Inspection of feed tube X X X X X 18. Replacement of drive belts, support brgs., & seals X 19. Replacement of deflectors, scrapers (D7L), & nozzles X 20. General complete mechanical overhaul & inspection X * Except item 1, the intervals above are from beginning i operation. When 24000 hrs is reached, revert back to beginning of chart. Previous Slide
Simple rules of thumb for operating any piece of equipment The Harder you run it the more it will cost you to maintain it The Faster you operate and unit (above its performance optimum speed) the more wear you will have The more solids you put through a unit (above it s optimum performance range) the more wear you will have in the unit The more grit or non biological particulate you have in the sludge the more wear and plugging that will occur The less housekeeping you perform on a piece of equipment to faster the surfaces and housing will deteriorate The less Electrical upkeep that is performed on the controls and electrical components of a system stem the faster they will fail 15
YES - I SAID CONTROLS How many times have you heard It s a Mechanical problem when the motor won t start or the panel does not function. Electrical components have a shelf life and in today s market they have a Factory support life as well Most PLC units are good for 10 years OIT or HMI units are about the same or a little less Instrumentation seems to have a better cycle if taken care of VFD drives are supported by the factory for 10 years but some parts can be recycled to extend the life by a few years 16
Andritz Centrifuge Features 11. Centrifuge Control System NEMA 4X Stainless Steel 316L Control Panel with Color Touch Screen Previous Slide
CONTROL PANELS This is the heart of the operation if the controls are poor then the machine operation and performance are poor If the Control Panels are left open and allowed to have a poor quality air into the panel the wiring, instruments and controls can prematurely fail. If the conduits into the panels are not sealed off then what ever can get into the conduits is inside the panels If the air conditioners (and most do have them if they have VFD s) filters and inlets are not serviced and the efficiency of the conditioned air is affected the heat generated inside the panel can reach 150 deg F and the function of the PCL and HMI (along with other controls) can fault. If the controls on the machines are SO cord with plastic grommet fittings they are in direct contact with the operating atmosphere, possible damage and the big feet of most Maintenance people (OPS) these need to be inspected at timely intervals for damage and wear. 18
GENERAL NOTES General Housekeeping is never a bad thing All lubes and oils should be changed at least twice a year regardless of operating hours Filters are always changed with the oils - these include air, oil, water and screens. Never operate a unit that one does not feel comfortable operating if a guard is missing or left off after a service report it and correct it If something is showing signs of wear, erosion or corrosion replace it do not operate it Motors need love too they have lubrication intervals or life cycles (sealed bearings) and the loads on the shafts require alignment and they should be checked during required service Belts the forgotten band belts do not last until the break they should be checked for cracks and replaced ar specified intervals 19
QUESTIONS: There are NO dumb questions 20 Individual footer (e.g. title of presentation, date, name of presenter): Arial 9 pt, gray, align center, max. 1 line
Previous Slide