Complete Asphalt Plant Part Maintenance Manual: In-Depth Coverage of Detailed Maintenance Procedures for Each Component

Introduction

This comprehensive maintenance manual covers detailed procedures for every critical component of modern asphalt mixing plants, from daily cleaning protocols to specialized repair techniques. Whether you operate a batch plant, drum mixer, or portable system, this guide provides the technical knowledge necessary to implement an effective maintenance program.

Part 1: Understanding the Asphalt Plant Maintenance Framework

Why Asphalt Plant Part Maintenance Matters

• Reduced Production Efficiency: Clogged components and worn parts force the plant to work harder, consuming more fuel

• Quality Degradation: Inconsistent mixing, uneven heating, and contamination compromise asphalt specifications

• Safety Hazards: Loose fasteners, failing bearings, and electrical malfunctions create workplace dangers

• Escalating Repair Costs: Minor issues become catastrophic failures requiring complete component replacement

• Environmental Non-Compliance: Poor baghouse maintenance increases emissions; inadequate burner tuning wastes fuel

Developing Your Maintenance Schedule

Most manufacturers provide baseline schedules, but your specific maintenance intervals should be customized based on plant utilization, local material characteristics, and operating environment.

Part 2: Critical Asphalt Plant Components and Detailed Maintenance Procedures

DRYING DRUM: The Heart of Your Asphalt Plant

Daily Drying Drum Maintenance

• Visually inspect the exterior drum shell for cracks, rust, or unusual wear patterns

• Remove debris, dust, and asphalt buildup from the outside surface

• Check the internal flights (mixing blades) for visible damage through access ports

• Clear any accumulated material near the inlet that could cause plugging

• Document shell conditions in your maintenance log for trend analysis

• Use an infrared thermometer to measure shell temperature at regular intervals (approximately every 3 feet along the drum length)

• Take readings at both maximum and reduced throughput rates to establish baseline performance

• Abnormal temperature distribution indicates internal wear or flight deterioration

• Record all temperature data to identify thermal anomalies early

• Lubricate drive motor bearings according to manufacturer specifications using appropriate high-temperature grease

• Apply lubricant to the trunnion wheel bearings that support the rotating drum

• Grease all accessible bearings on the gear reduction system

• Check that lubrication points are not blocked by debris or rust

• Never over-lubricate, as excess grease creates heat and attracts contamination

Monthly/Seasonal Drying Drum Maintenance

• Measure and photograph all flights currently installed—their position, quantity, spacing, and condition

• Compare actual configuration to factory drawings and maintenance records

• Analyze burner performance by monitoring outlet duct temperatures at 8-10 inch intervals

• If flights are worn more than 1/3 of their original thickness, schedule replacement

• Drain all fuel and power down the system using proper lockout/tagout procedures

• Allow the drum to cool completely (typically 4-8 hours minimum)

• Remove bolts securing worn flights using a socket wrench set

• Install new flights using matching specifications—improper flight configuration reduces efficiency

• Tighten all fasteners in a cross-pattern to ensure even seating

• Inspect welds and connections for integrity before returning to service

• Inspect trunnion rings for uneven wear patterns that indicate misalignment

• Check bearing play by attempting to move the drum laterally—excessive movement indicates worn bearings

• If wear extends beyond the hardening point or shows severe metal flaking, schedule replacement

• Lubricate trunnion assemblies at scheduled intervals using a special fixture for precise application

• Replace oil in drive reducers during scheduled maintenance periods

• Deep clean burner head, nozzle, and combustion chamber

• Replace fuel nozzles (cannot be cleaned effectively once removed)

• Inspect CAD cell window for clarity

• Check ignition electrodes for proper gap and cleanliness

• Verify flame shape and color during test firing

MIXER/MIXING CYLINDER: Precision Blending Equipment

Daily Mixer Maintenance

• Inspect door seal condition for tears, cracks, or deterioration

• Clean sealing surfaces of accumulated asphalt and aggregate material

• Verify that door opens and closes smoothly without binding

• Check that latching mechanism holds door securely during operation

• Replace seals if leakage is observed during mixing cycles

• Listen for unusual grinding, squealing, or rattling sounds indicating bearing problems

• Check for asphalt or water leakage around shaft seals

• Monitor bearing temperature by touch (after shutdown) or infrared thermometer

• If bearings feel hot or vibration increases, plan immediate maintenance

• Open mixer access doors during downtime and visually inspect all mixing blades

• Check blade thickness—replace blades if worn more than 1/3 of original thickness

• Inspect blade weld points for cracks or separation

• Examine mixer liners (internal barrel coating) for adherence and wear

• Document blade and liner condition to predict replacement timing

Monthly Mixer Maintenance

1. Power down and apply lockout/tagout

2. Allow mixer to cool completely

3. Open bottom mixer access panel

4. If bearing is seized: carefully use cutting torch to cut race (wear proper PPE)

5. Use bearing puller with appropriate socket to remove outer bearing race

6. Remove bolts holding bottom seal assembly

7. Slide bearing and seals out carefully

8. Note seal orientation before removal

9. Apply lubricating grease to new seals before installation

10. Press new seals into position with even pressure applied to tri-clamp fitting

11. Insert threaded adapter and tighten bolts in X-pattern, turning 1 full turn per bolt at each pass

12. Rotate assembly by hand to verify smooth operation before closing

13. Reassemble housing and close access panel

• Inspect both seal ends for leakage or damage

• Replace O-ring seals if worn, cracked, or degraded

• Apply vacuum grease to seal surfaces before installation

• Ensure flat portion of seal faces center of shaft

• Lubricate O-ring before pressing into fitting

• Check oil levels in gearbox using sight glass or dipstick

• Change gearbox oil annually or per manufacturer schedule

• Monitor gearbox temperature during operation

• Inspect for unusual noise or vibration patterns

• Check motor ventilation openings for blockages

• Verify motor is properly connected to drive coupling with secure fasteners

BAGHOUSE DUST COLLECTOR: Environmental Protection and Efficiency

Daily Baghouse Maintenance

• Visually inspect all filter bags for tears, holes, or damage

• Check that bags are properly seated in their cages without gaps

• Verify bags show even dust loading without concentrated buildup in specific areas

• Spot-check bag tension by carefully touching (when safe) to assess firmness

• Look for fabric discoloration that indicates heat damage or chemical attack

• Document any damaged bags for replacement

• Check and record differential pressure (pressure drop across filter system) daily

• Normal operating pressure differential: 3-4 inches of water

• Excessive differential pressure (>6 inches) indicates filter saturation

• Low differential pressure (<2 inches) suggests torn bags or improper cleaning

• Maintain a log tracking daily pressure readings for trend analysis

• If differential pressure rises consistently, investigate cause before failure occurs

• Inspect hopper for dust accumulation and proper discharge

• Verify that discharge valve operates smoothly and seals completely

• Check that dust removed from hopper flows freely to collection point

• Clean areas around hopper to prevent material compaction

• Verify compressed air system providing pulse cleaning has adequate pressure

• Visually observe exhaust stack during operation

• Any visible dust discharge indicates damaged bags or system malfunction

• If dusting occurs, stop plant and investigate immediately

• Use opacity monitor if equipped to verify compliance measurements

Monthly Baghouse Maintenance

1. Record the position and configuration of all bags before removal

2. Power down pulse cleaning system and allow compressed air to discharge

3. Depressurize baghouse using bleed valve

4. Allow system to cool (typically 30-60 minutes)

5. Open baghouse access door using proper confined space procedures

6. Remove damaged bags by sliding upward from cage

7. Inspect cage structure for damage that might have caused bag failure

8. Install new replacement bags by sliding onto cage posts

9. Ensure bags are fully seated with no twists or folds

10. Verify complete sealing between bag base and cage

11. Close access door with proper gasket and fastener torque

12. Restore system pressure gradually before resuming operation

• Inspect pulse valve solenoids for damage or corrosion

• Test pulse valve operation by listening for clearing cycles

• Check pulse cleaning timing—bags should inflate at programmed intervals

• Verify compressed air reaching valves has adequate pressure (typically 80-100 psi)

• Replace diaphragm kits if air leakage detected around valve stems

• Inspect airline connections for loose fittings or leaks

• Replace air dryer cartridges in compressed air system monthly

• Check air filter elements in compressed air unit for saturation

• Perform visual inspection inside baghouse using proper confined space procedures

• Document any debris, corrosion, or bag damage visible on interior

• Check dust hopper interior for material accumulation or bridging

• Inspect distribution plates for clogging or uneven air flow

• Clean all internal surfaces if heavy dust accumulation observed

• Check lifting valve operation and gasket seal condition

• Verify bypass damper (if equipped) operates properly to protect bags during startup

BURNER AND COMBUSTION SYSTEM: Heat Generation and Control

Daily Burner Maintenance

• Observe burner flame through sight glass (use proper eye protection)

• Flame should be blue (not yellow/orange) indicating complete combustion

• Flame shape should be cone-shaped and stable, not flickering or pulsing

• Note any unusual flame colors indicating fuel/air ratio problems

• Check flame detector signal on control system indicating proper ignition

• Document any abnormalities for technician investigation

• Verify fuel pump operating normally without unusual noise

• Check fuel supply tank level and ensure adequate supply

• Inspect fuel lines for leaks at connections and along routing

• Ensure fuel filter basket is not blocked (visual inspection if accessible)

• Check fuel pressure gauge reading (if equipped) against normal operating range

• Note any fuel odors or spills requiring immediate attention

• Remove accessible debris and dust from burner head

• Check mounting bolts and fasteners for tightness

• Verify burner can move smoothly in mounting bracket if adjustable

• Inspect fuel supply hose routing for damage or excessive heat exposure

• Check that burner clearance from equipment remains adequate

Quarterly/Annual Burner Service

1. Ensure complete system shutdown and cool-down (minimum 30 minutes)

2. Apply lockout/tagout to all energy sources

3. Locate fuel line connection to burner housing

4. Disconnect fuel line from fuel delivery tube using adjustable wrenches

5. Remove plate holding entire delivery system to burner housing

6. Slide delivery system assembly out through top of burner housing

7. Using two adjustable wrenches, remove nozzle from delivery tube:

1. One wrench holds tube steady

2. Second wrench turns nozzle counterclockwise

8. Do not attempt to clean removed nozzle—dispose of safely

9. Treat new nozzle only where wrench makes contact (same as halogen light bulb precautions—skin oils damage nozzle)

10. Install new nozzle using reverse procedure, snugging firmly but not over-tightening

11. Reconnect fuel delivery system and secure mounting plate

12. Reconnect fuel line and verify no leaks

13. Perform test firing and verify proper flame pattern

• Remove burner head to access igniter components

• Inspect electrodes for pitting, fouling, or burning

• Check electrode gap matches burner specifications (typically 3-4mm)

• Clean electrode surfaces using fine sandpaper or wire brush

• Verify igniter produces spark when burner cycles

• Replace igniter if spark weak or absent

• Check CAD cell (flame detector) window for soot or discoloration

• Clean CAD cell using soft cloth and acetone if contaminated

• Locate fuel filter basket between tank and fuel pump

• Turn fuel shutoff valve to isolate tank

• Remove filter housing bowl using wrench

• Withdraw basket and inspect for debris, water, or rust

• If contamination evident, clean basket with compressed air or brush

• Drain any water from filter bowl

• Dry basket thoroughly before reinstalling

• Apply fuel-resistant gasket sealer to threads before reassembling

• Restore fuel supply and check for leaks

• This procedure requires specialized equipment and training

• Contact authorized burner technician for professional calibration

• Improper air-fuel adjustment increases emissions and reduces efficiency

• Combustion analysis equipment measures oxygen content in exhaust gas

• Ideal combustion maintains 2-3% oxygen in flue gas

• Document calibration date and settings in maintenance records

CONVEYOR BELT SYSTEM: Material Transport

Daily Conveyor Maintenance

• Walk the entire length of belt on both sides

• Look for tears, fraying, seam separation, or edge curling

• Check for unusual slippage or squealing during operation

• Observe belt tracking—it should remain centered on pulleys

• Note any material buildup or spillage along the system

• Check for moisture damage or rubber degradation

• Listen for grinding sounds indicating pulley misalignment

• Verify belt shows proper tension by applying hand pressure mid-span

• Belt should have slight deflection (typically 10-15mm under moderate pressure)

• Too-loose belts slip; too-tight belts cause premature bearing wear

• Observe belt alignment relative to pulley edges

• If belt drifts toward one side, adjust tracking bolts incrementally

• Never adjust both sides simultaneously—adjust one side only per shift

• Check all visible bolts, nuts, and fasteners along conveyor frame

• Tighten any loose fasteners immediately

• Look for rust or corrosion requiring replacement

• Inspect belt splice connections if belt recently replaced

• Verify pulley mounting bolts remain secure

Monthly Conveyor Maintenance

1. Clean conveyor bed of all debris and material

2. Verify motor is OFF and locked out

3. Install replacement belt if old belt shows damage

4. Apply initial tension (pre-tension) so belt just moves with hand pressure

5. Ensure all rollers are square to belt path

6. Mark two points on belt exactly 100 inches apart, perpendicular to centerline

7. Gradually increase tension using jack or tensioning device

8. Measure distance between marks as tension increases

9. Apply tension until marks reach calculated distance per manufacturer specs

10. Example: If 0.5% tension specified, tension to 100.5" (0.5% of 100")

11. Once proper tension achieved, verify belt remains square and centered

12. Run belt slowly to confirm proper tracking before resuming normal operation

13. Re-check tension after 24 hours of operation (new belts stretch initially)

• Remove belt or access underside (if safe and equipment powered down)

• Inspect all pulleys for lagging wear or rubber degradation

• Check pulley bearing condition—listen for grinding or unusual noise

• Verify pulley surfaces are smooth without cracks or divots

• Replace pulley lagging if worn more than 50% of original thickness

• Lubricate pulley and roller bearings according to schedule

• Check roller alignment perpendicular to belt path using straight edge

• Replace bearings showing excessive play or damage

• Check motor mounting bolts for tightness

• Verify motor ventilation openings are not blocked

• Inspect electrical connections for corrosion or looseness

• Check motor bearing condition by listening for unusual noise

• Verify motor shaft coupling is secure

• Review motor current draw compared to baseline

• Ensure motor has adequate lubrication per manufacturer schedule

VIBRATING SCREEN: Separation and Grading

Daily Screen Maintenance

• Clean screen mesh of all material between every production run

• Remove caked-on material using brush or compressed air

• Visually inspect mesh for tears, holes, or deformation

• Check mesh attachment at frame edges for security

• Look for blocked apertures reducing screening efficiency

• Observe uneven wear patterns indicating misalignment

• Inspect all bolted connections for looseness caused by vibration

• Tighten any loose bolts immediately using appropriate wrench

• Look for cracks in welds or frame structure

• Check that screen frame remains square during operation

• Verify mounting springs and isolation bushings are intact

• Listen for unusual rattling indicating loose internal components

• Check exciter/vibrator temperature by infrared measurement after operation

• Excessive temperature indicates bearing problems or misalignment

• Listen for unusual grinding noise from vibration unit

• Verify vibration unit mounting bolts remain tight

• Check lubrication level in vibrator bearings if accessible

Monthly Screen Maintenance

1. Power down screen and apply lockout/tagout

2. Allow screen to cool (typically 15-30 minutes)

3. Remove bolts securing mesh to frame using socket wrench

4. Carefully lift worn mesh from frame

5. Clean frame edges of material residue using brush and compressed air

6. Position new mesh on frame ensuring even alignment

7. Partially tighten all bolts in cross pattern to hold mesh temporarily

8. Verify mesh is flat and square relative to frame

9. Progressively fully tighten bolts, alternating corners to maintain even pressure

10. Ensure mesh sits flush against frame with no wrinkles or folds

11. Manually rotate screen to verify smooth operation before powering on

12. Run at low speed initially to confirm proper mesh seating

• Inspect rubber springs/isolators for cracking or deterioration

• Replace springs if cracks visible or rubber disintegrating

• Check that screen isolation system reduces vibration transmission to plant frame

• Verify springs are properly loaded with correct spacing

• Ensure spring mounting bolts are tight

• Check vibrator bearing play by attempting to move shaft

• Excessive play indicates worn bearings requiring replacement

• Verify vibration unit mounting bolts are secure

• Check oil level in vibrator if enclosed bearing design

• Listen during operation for grinding or rattling indicating problems

• Replace bearings showing excessive play or unusual noise

BITUMEN STORAGE AND HEATING SYSTEM

Daily Bitumen System Maintenance

• Check thermometer reading to verify tank temperature within specification (typically 140-180°C)

• Verify temperature control system maintaining proper setpoint

• Note any temperature fluctuations or instrument errors

• Check that heating system cycling on/off normally

• Observe that tank insulation remains intact without damage

• Inspect all pipe connections, valves, and tank for leaks

• Check fuel supply level and note if consumption is normal

• Verify fuel lines and connections are secure without damage

• Listen for unusual noise from heating system components

• Observe piping for insulation deterioration or damage

• Check external tank condition for rust, corrosion, or damage

• Verify tank supports and foundation remain solid

• Check that access ladder and handrails are secure

• Observe tank level indicator for proper operation

• Verify high-level alarm system functioning if equipped

Monthly Bitumen System Maintenance

1. Allow system to cool to ambient temperature (4-8 hours minimum)

2. Apply lockout/tagout to heating system

3. Locate oil level sight glass on boiler

4. Check that oil level is within proper range (typically mid-sight glass)

5. If low, add specified thermal fluid (never mix oil types)

6. Verify oil color—if very dark or discolored, plan oil change

7. Check all oil line connections for leaks or seeping

8. Inspect insulation around oil piping for damage or deterioration

9. Replace damaged insulation to maintain efficiency

• Verify bitumen pump seals are not leaking asphalt

• Check pump discharge pressure gauge reading (if equipped)

• Listen for unusual pump noise indicating cavitation or bearing problems

• Verify all isolation valves operate smoothly

• Check that pressure relief valve is functioning (consult technician if unsure)

• Inspect line strainers for blockage

• Replace strainer elements if pressure drop excessive

• Inspect burner head for cleanliness and proper firing

• Check that burner flame is blue and stable during operation

• Verify fuel supply and combustion air mixture proper

• Clean burner nozzle if carbon buildup observed

• Check burner mounting for security and proper positioning

1. Plan annual tank inspection during plant shutdown

2. Drain tank completely using discharge valve

3. Allow tank interior to cool to ambient temperature

4. Open manhole and observe interior condition

5. Remove excess sediment and debris from tank bottom

6. Inspect interior surfaces for corrosion or degradation

7. Check heating coils/tubes for scale buildup or corrosion

8. Use wire brush to remove light corrosion or scale

9. Flush interior if sediment accumulation occurred

10. Clean and inspect inlet/outlet nozzles

11. Refill tank with fresh bitumen and verify heating system operation

AGGREGATE COLD FEED AND WEIGHING SYSTEM

Daily Cold Feed Maintenance

• Visually verify that all aggregate feeder gates are at proper openings

• Compare current gate positions to calibration chart placards

• Note any drift from specified positions

• Check that gates move smoothly without sticking or binding

• Listen for unusual noise from gate actuators

• Observe material flowing from each cold feed bin into elevator

• Verify all materials flowing at consistent rates (no surging or stoppage)

• Check that materials combine uniformly without segregation

• Monitor for material blockage in bin discharge areas

• Inspect bin level indicators for accuracy

• Verify all bins have adequate material at quarter-point markers

• Check that low-level alarms activate before bins empty completely

• Ensure bin refilling occurs before shutdown of material feed

• Monitor for material bridging or caking in bin discharge

• Check that level sensors are functioning properly

Monthly Cold Feed Maintenance

1. Stop all production and allow equipment to settle

2. Ensure bins are adequately filled with material to be calibrated

3. Open material gate to specified position per calibration chart

4. Allow material to flow into collecting bin or scale for timed period (typically 1-5 minutes)

5. Weigh collected material or measure volume

6. Calculate actual flow rate in pounds or tons per minute

7. If actual flow does not match target within acceptable tolerance (typically ±5%), adjust gate position

8. Re-test and adjust until flow rate matches calibration chart

9. Secure gate adjustment and verify setting remains stable

10. Document final calibration settings and date in maintenance log

1. Power down plant and apply lockout/tagout to scale systems

2. Using certified test weights or chain links, place known weight on scale platform

3. Read scale display and compare to actual weight

4. If error exceeds ±0.5%, contact certified scale technician

5. Verify all load cells are functioning by weight test on each position

6. Check for debris or material buildup on scale mechanism

7. Lubricate scale pivot points and slide components per manufacturer schedule

8. Verify scale digital display reads accurately and updates properly

9. Test data transmission to control system if scale data used for recipe verification

• Verify all bin level sensors functioning by observing indicator display

• Test high-level and low-level alarms by raising/lowering material levels

• Clean sensor lenses of accumulated dust or moisture

• Verify sensor mounting brackets are secure

• Check electrical connections for corrosion or looseness

• If readings inaccurate, contact sensor manufacturer for recalibration

CONTROL SYSTEM AND ELECTRICAL COMPONENTS

Daily Control System Monitoring

• Verify all status lights on control panel indicate normal operation

• Check that no alarm lights or error messages are displaying

• Review control system display for any warning indicators

• Note any messages requiring attention and document in log

• Verify that all sensor inputs (temperature, pressure, flow) are within normal ranges

• Confirm plant control display screen is readable without glitches

• Verify all relevant data (temperatures, flows, batch counts) are displaying accurately

• Check that manual override controls respond appropriately when tested

• Ensure emergency stop buttons are clearly visible and accessible

• Verify navigation through control menus functions smoothly

• Confirm plant is recording batch data and production logs

• Verify timestamp accuracy of all recorded data

• Check that backup system is functioning for critical data

• Note any data gaps or recording errors

• Ensure database is not approaching storage capacity limits

Weekly Control System Maintenance

1. Power down plant using proper shutdown procedures

2. Apply lockout/tagout to electrical system

3. Open electrical control cabinet/panel

4. Visually inspect all internal components for dust accumulation

5. Check that all terminal connections are tight without corrosion

6. Look for loose wires or damaged insulation

7. Verify all circuit breakers and fuses are secure

8. Check contactor contacts for pitting or burning (consult electrician if severe)

9. Inspect cooling fan operation and clean intake filters

10. Close panel securely

• Verify all sensor cables are properly routed without kinks or damage

• Check that connectors are fully seated and free of corrosion

• Tighten any loose connection bolts or fasteners

• Look for cut or abraded wire insulation requiring replacement

• Verify grounding connections are clean and tight

• Note system uptime and any unexpected resets or reboots

• Check internal system temperature and cooling system operation

• Verify all input/output module indicator lights functioning correctly

• Review any error logs for recurring issues

• Backup system data if not automatically backed up

Monthly Control System Maintenance

• Contact control system manufacturer for any available software updates

• Review update release notes for improvements or bug fixes

• Schedule updates during downtime periods to avoid production interruption

• Back up current system configuration before installing updates

• After update installation, verify all functions operating correctly

• Maintain backup of critical system data separate from main storage

• Verify scale readout matches weight applied for linearity check

• Test scale response by adding weight incrementally

• Check that scale zero reference is correct before production run

• Verify scale data transmission to control system

• If scale errors detected, contact certified scale technician

• Compare instrument readings to secondary portable meters if available

• Check sensor response time by monitoring changes during production

• Verify sensor output signals within expected voltage range (typically 4-20mA)

• Clean sensor calibration blocks or reference points

• Contact sensor manufacturer if readings consistently off specification

Part 3: Seasonal and Extended Shutdown Maintenance

Pre-Season Startup Procedures (Spring)

• Inspect all major structural components for damage or deterioration

• Check all bolted connections and fasteners throughout plant

• Verify protective covers or seals remain intact

• Test all safety interlocks and emergency systems

• Run through complete control system startup sequence

• Cycle all motors, pumps, and actuators through full range of motion

• Check fluid levels in all gearboxes, motors, and hydraulic systems

• Verify all belts and chains have proper tension

• Test all alarm and warning systems

• Perform full plant cycle at reduced speeds before full production

• Flush bitumen lines and verify smooth flow

• Replace any fuel filters that were stored during winter

• Verify cold aggregate bins are dry and contain no moisture

• Test all material flow paths to confirm no blockages

Fall/Winter Shutdown Procedures (Off-Season)

• Thoroughly clean all hot-side components including mixer, dryer, and piping

• Remove asphalt and aggregate buildup to prevent hardening

• Clean bitumen lines and pump systems to prevent coating

• Drain all residual material from access points and sumps

• Clean dust collection system including baghouse and ductwork

• Drain all water from air systems using compressed air blowdown

• Drain water separator in compressed air unit

• Close all drain valves after complete drainage

• Drain fuel oil lines if diesel fuel used (winter cold can gel fuel)

• Do NOT drain thermal oil from heating system (consult manufacturer on preservation method)

• Drain water from conveyors and other water-trapping areas

• Apply anti-rust oil to all exposed steel surfaces and fasteners

• Cover motors and electrical components with protective covers

• Seal openings to prevent moisture and pest intrusion

• Remove small parts (bolts, fasteners, instruments) prone to loss

• Document removal of items for spring reinstallation

• Place desiccant packets in enclosed areas to reduce moisture

• Cover open bin tops to prevent rain entry

• Close all fuel supply valves

• Shut down compressed air system and store properly

• Close all material isolation valves

• Apply lockout/tagout labels to all energy sources

• Document shutdown procedures and status in maintenance log

• Perform detailed thickness measurements on dryer drum shell and flights

• Measure trunnion ring wear using ultrasonic or caliper tools

• Inspect concrete foundations for cracks or settling

• Check structural steel for rust development or damage

• Examine all welds for stress cracks that developed during season

• Document all findings for next season's maintenance planning

Part 4: Advanced Maintenance Topics

Lubrication Program Development

• Lubrication reduces friction between moving parts, minimizing wear

• Proper lubricant type and viscosity must match bearing design and operating temperature

• Over-lubrication causes excessive heat and attracts contamination

• Under-lubrication accelerates bearing wear and failure

• High-temperature environments require grease with higher melting points

1. Consult manufacturer documentation for all equipment

2. Create list of all lubrication points including location, lubricant type, and quantity

3. Establish lubrication intervals based on equipment operating hours

4. Assign specific staff responsibility for lubrication tasks

5. Create checklist showing location, lubricant type, and last service date

6. Train staff on proper greasing technique (apply to bearing, not surrounding area)

• Conveyor belt roller bearings (typically 1-2 ounces grease per bearing monthly)

• Dryer drive motor bearings and shaft seals

• Mixer drive gearbox (change oil annually, check monthly)

• Vibrating screen exciter/vibrator bearings

• Cold feed conveyor system throughout

• All chain drives throughout plant

• Control system cabinet cooling fan bearing

• Pump seals on bitumen and asphalt systems

• Use lubricants specified by equipment manufacturer (follow OEM recommendations exactly)

• High-temperature applications (near dryer): NLGI Grade 2 or 3 grease rated to 200°C+

• Normal temperature bearings: NLGI Grade 2 multipurpose lithium grease

• Chain lubrication: automatic chain oil or penetrating chain lubricant

• Motor bearings: oil-based lubricant with additives for wear protection

• Never mix lubricant types on same application

Predictive Maintenance Using Condition Monitoring

• Excessive vibration indicates bearing wear, misalignment, or imbalance

• Use hand-held vibration meter to measure relative vibration levels

• Compare measurements over time to identify increasing vibration trends

• Establish baseline measurements when equipment new or newly serviced

• Alert technicians when vibration increases beyond normal range

• Schedule replacement before catastrophic bearing failure

• Infrared camera measures surface temperatures revealing internal problems

• Overheating bearings indicate inadequate lubrication or impending failure

• Hot spots on electrical connections indicate loose connections or high resistance

• Dryer drum temperature profiling shows internal flight wear or buildup

• Thermal imaging helps identify insulation damage or missing covers

• Periodic oil sampling from gearboxes reveals metal content indicating wear

• Increased iron particles indicate bearing or gear wear

• Water content indicates seal leakage or condensation issues

• Acidity or viscosity change indicates oil degradation

• Regular analysis establishes normal parameters for comparison

• Experienced technicians can identify problems by listening to equipment

• Grinding sounds indicate bearing problems or internal wear

• Squealing suggests inadequate lubrication or misalignment

• Rattling indicates loose components or fasteners

• Unusual noise patterns should prompt investigation and documentation

Spare Parts Inventory Management

• Conveyor belt splice kits and replacement belts (calculate length needed)

• Mixer blades and liners (20-30% of replacement set)

• Baghouse filter bags (complete spare set minimum)

• Burner nozzles and ignition electrodes (2-3 of each type)

• Drive belts for all motors and fans

• Bearing and seal kits for motors and mixers

• Motor brushes for electric motors with brushes

• Electrical fuses and circuit breaker components

• Temperature and pressure sensors

• Store spare parts in dry, temperature-controlled environment

• Organize inventory by plant component (dryer, mixer, conveyor, etc.)

• Maintain detailed inventory list with part numbers and quantities

• Rotate stock using FIFO (First In First Out) principle

• Inspect stored parts periodically for deterioration

• Keep updated purchase information and supplier contact details

• Establish minimum stock levels triggering reorder

• Maintain warranty documentation and shelf-life information

Part 5: Troubleshooting Common Problems

Poor Mix Quality and Segregation

• Calibrate aggregate feeders using prescribed procedure (detailed above)

• Verify all scales reading within ±0.5% accuracy

• Inspect mixer for worn blades affecting mixing uniformity

• Check dryer outlet temperature consistency along drum length

• Verify bitumen being applied evenly across mix

• Examine mixer discharge gate operation—ensure complete discharge

• Confirm proper holding bin management without excessive time

Excessive Fuel Consumption

• Verify burner air-fuel ratio properly calibrated (requires professional)

• Inspect dryer drum flights for wear reducing heat transfer efficiency

• Check drum shell insulation for damage or deterioration

• Verify baghouse filters not excessively clogged increasing restriction

• Inspect conveyor belt tension (excessive tension increases motor load)

• Check for material leakage or spills requiring system pressure increase

• Verify bitumen pump not cavitating or requiring excessive pressure

• Confirm thermal efficiency not degraded by scale buildup

Equipment Vibration and Noise

• Inspect all fasteners throughout plant for looseness—tighten systematically

• Check bearing play using hand deflection test—replace if excessive

• Verify motor/gear coupling alignment using straight edge

• Inspect conveyor belt tracking and re-center if misaligned

• Examine mixer for internal obstruction or broken blade

• Check dryer drum trunnion wear using measurement tools

• Verify baghouse bag tension and proper seating

• Use vibration meter to establish baseline and track changes

Burner Flame Issues

• Verify fuel supply adequate and reaching burner

• Inspect fuel filters for blockage—replace if clogged

• Check fuel pressure against specifications

• Verify ignition electrodes clean and properly gapped

• Inspect CAD cell (flame detector) window for soot

• Confirm combustion air supply adequate without blockage

• Check fuel nozzle for carbon accumulation (requires professional cleaning/replacement)

• Verify burner mounting position hasn't shifted affecting air/fuel mix

Baghouse Pressure Differential Issues

• Inspect filter bags for clogging or dust caking

• Verify pulse cleaning system operating at correct frequency

• Replace air compressor filter element if supply pressure low

• Check pulse valve solenoids operating properly

• Examine baghouse inlet ductwork for blockage

• Inspect bags for poor seating allowing bypass

• Verify inlet temperature not excessive (above specification)

• Search for torn or holes in filter bags using visual inspection

• Check for dust clouds exiting stack indicating leakage

• Verify gasket seals intact on all baghouse access doors

• Inspect bag cage for damage allowing bypass

• Check lifting valve operation if equipped

• Examine distribution plate for clogging

Part 6: Maintenance Documentation and Record Keeping

Maintenance Log System

• Date and time of maintenance task

• Component or system serviced

• Technician or operator performing maintenance

• Work performed and findings

• Parts replaced (part number and quantity)

• Downtime duration (if applicable)

• Cost of parts and labor

• Next scheduled maintenance date

• Any recommendations for future attention

• Maintain both digital and physical backup of critical records

• Store records accessible to all maintenance staff

• Update records immediately after work completion

• Review records periodically to identify recurring issues

• Analyze trend data to optimize maintenance intervals

Developing Equipment History

• Identifies chronically problematic components requiring replacement

• Reveals maintenance intervals needing adjustment

• Shows patterns indicating root cause issues

• Justifies equipment upgrade or replacement decisions

• Supports warranty claims with detailed documentation

• Assists new technicians learning equipment history

Conclusion

• Superior Product Quality: Consistent mix design, no segregation, proper temperature control

• Reduced Operating Costs: Optimal fuel efficiency, minimal emergency repairs, extended component life

• Improved Safety: Properly functioning equipment with eliminated hazards

• Regulatory Compliance: Environmental standards met through effective dust collection and burner control

• Increased Profitability: Higher production rates, better customer satisfaction, premium pricing capability