Milling and Grain Processing Systems Troubleshooting Guides
Safety Warnings
Irregular Milling Between Roll Stocks
Roll Adjustment Mechanism Problems
Milling and Grain Processing Systems Troubleshooting Guides
Quick and effective resolution of problems encountered in milling and grain processing facilities is critically important for production continuity and equipment life. These comprehensive troubleshooting guides provide step-by-step instructions for diagnosing and resolving the most common equipment failures.
Safety Warnings
Before starting any troubleshooting operation:
- Always cut power and apply lockout-tagout (LOTO) procedures before working on equipment
- Use appropriate personal protective equipment (gloves, glasses, dust masks, etc.)
- Ensure protective guards are in place when working with moving parts
- Seek technical service support for equipment you are not authorized to work on
- Follow all safety procedures and manufacturer instructions
Roll Systems Troubleshooting Guides
Roll Operation Problems and Solutions
Roll Motor Overheating Problem
Symptoms:
- Unusual temperature increase in motor housing
- Excessive current draw
- Protection relay tripping
- Burning smell
Solution Steps:
- Cut power and wait for motor to cool
- Check bearing sounds after motor cools
- Measure motor current and compare with nominal values
- Check for excessive pressure between roll stocks
- Check belt tension; excessive tension overloads the motor
- Check cleanliness of motor cooling fan and ventilation channels
- Measure insulation resistance of motor windings
- Ensure roll differential speed is correctly adjusted
Irregular Milling Between Roll Stocks
Symptoms:
- Inconsistency in milling granulation
- Deterioration in flour quality and yield reduction
- Regional wear on rolls
- Variability in particle size during product control
Solution Steps:
- Check roll parallelism (distance between roll stocks should be equal at all points)
- Make shim adjustment for parallelism
- Check roll surface; repair or replace if there is wear or damage
- Ensure scraper blades are correctly positioned
- Check that roll feed system distributes product evenly along roll length
- Check roll pressure system to ensure equal pressure is applied
Roll Adjustment Mechanism Problems
Parallel Adjustment Problems and Correct Alignment
Symptoms:
- More milling on one side of roll stocks
- Unbalanced wear on rolls
- Abnormal sounds in roll drive system
Solution Steps:
- Check parallelism of roll stocks with special measuring instruments
- Use adjustment mechanisms at both ends of the roll for alignment adjustment
- Tighten fixing screws after adjustment
- Recheck parallelism and make fine adjustments if necessary
- Test operation by running rolls at slow speed
- Check for looseness in roll bearing connections
Roll Pressure System Problems
Roll Product Quality Problems
Sifter Systems Troubleshooting Guides
Sieve Opening Clogging and Cleaning
Roll Pressure System Problems
Symptoms:
- Variable milling quality
- Inability to maintain constant pressure between rolls
- Slipping of adjustment mechanism
Solution Steps:
- Remove pressure springs to check for damage
- Check spring tension and elasticity
- Check pressure piston and locking mechanism
- Check oil level and pressure in hydraulic pressure systems
- Ensure pressure indicators are working correctly
- Ensure locking mechanism is fully seated
Roll Product Quality Problems
Excessive Fine or Coarse Milling Problems
Symptoms:
- Particle size different from desired
- Change in extraction rate
- Clogging or insufficient separation in sifter system
Solution Steps:
- Check roll gap and adjust according to product type
- Check differential speed ratio (2.5:1 recommended for break, 1.5:1 for reduction)
- Check roll flute profile; replace roll stocks if there is wear
- Check roll feed amount; excessive or low feeding affects milling quality
- Check product moisture content; deviation from optimum values affects milling quality
- Take samples from mill flour and perform laboratory analyses
Sifter Systems Troubleshooting Guides
Sifter Performance Problems and Solutions
Sifter Capacity Deficiency and Efficiency Optimization
Symptoms:
- Excessive product accumulation on sifter
- Decrease in amount of sifted product
- Insufficient or irregular product flow under sifter
Solution Steps:
- Check sifter load; optimum load rate should be 70-80%
- Check sieve cloths for clogging
- Check condition and effectiveness of cleaning balls
- Check sifter vibration frequency and amplitude
- Check airflow and aspiration system
- Check sieve cloth tension and adjust if necessary
- Check moisture content of sifted material; high moisture reduces sifter performance
Sieve Opening Clogging and Cleaning
Symptoms:
- Decrease in sifting capacity
- Slowdown in product passage
- Material accumulation on sieve upper surface
Solution Steps:
- Check number and condition of sieve cleaning balls
- Check diameter and hardness of cleaning balls; replace worn balls
- Remove sieve cloths and clean with appropriate brush or compressed air
- Clean accumulated material in sieve channels if any
- Optimize aspiration system to prevent clogging
- Ensure no incompatible material with sieve cloth is being processed
Sifter Mechanical Problems
Sifter Drives and Eccentric Mechanism Failures
Symptoms:
- Abnormal vibration or sound
- Insufficient or irregular movement
- Motor overloading
Solution Steps:
- Check wear of eccentric shafts and bearings
- Ensure eccentric weights are correctly positioned
- Check tension of drive belts
- Check motor connections and chassis connections
- Check bearing components; replace worn bearings
- Verify positions of balance weights
- Check alignment between motor and drive system
Suspension System and Spring Failures
Symptoms:
- Unbalanced movement or swaying
- Vibration transmission and excessive noise
- Abnormal movement in sifter frame
Solution Steps:
- Check suspension springs and connections
- Replace broken or deformed springs
- Check spring connection points and bolts
- Verify springs have equal tension
- Check chassis connection strength
- Check condition of vibration dampers
Transport Systems Troubleshooting Guides
Pipeline Blockages and Opening Procedures
Mechanical Transport Problems
Cleaning and Tempering Systems Troubleshooting
Transport Systems Troubleshooting Guides
Pneumatic Transport System Problems
Insufficient Airflow and Low Pressure
Symptoms:
- Decrease in transport capacity
- Clogging in pipelines
- Decrease in fan or blower performance
Solution Steps:
- Measure fan or blower pressure and compare with nominal values
- Check air filter; clean or replace if dirty
- Perform leak control in pipelines
- Open pipes to check for blockages
- Check fan blades for wear or damage
- Check belt tension between motor and fan
- Ensure fan rotation direction is correct
Pipeline Blockages and Opening Procedures
Symptoms:
- Sudden stop in transport
- Abnormal values on pressure gauge
- Product accumulation in pipeline
Solution Steps:
- Shut down system and cut power
- Identify the blocked section (usually occurs at elbows and connection points)
- Open pipe connection points and observe blockage
- Clear blockage with a long rod or compressed air
- For dense blockages, remove pipes for cleaning
- After cleaning, close all connections leak-tight
- Start system at low capacity for testing
Mechanical Transport Problems
Elevator Belt Tension and Slipping Problems
Symptoms:
- Irregular bucket discharge
- Abnormal sound or vibration
- Capacity deficiency
- Material remaining in buckets
Solution Steps:
- Stop elevator and cut power
- Open inspection cover to check belt tension
- Use tensioning mechanism to achieve optimum tension
- Ensure belt is centered on pulleys
- Check bucket connections; secure loose buckets
- Check wear condition of upper and lower pulleys
- Check pulley alignment
Chain Conveyor Jamming and Breakage Problems
Symptoms:
- Chain sticking or making abnormal sounds
- Interruption in material flow
- Motor overload protection activation
Solution Steps:
- Stop conveyor and cut power
- Open inspection covers to check chain tension
- Check wear and damage in chain and sprockets
- Check condition of chain flights; replace damaged flights
- Ensure correct alignment of chain
- Use tensioning system to adjust optimum tension
- Check lubrication condition of sprockets and bearings
Cleaning and Tempering Systems Troubleshooting
Cleaning Systems Problems
Destoner Efficiency Deficiency and Setting Optimization
Symptoms:
- Observation of stones and heavy particles in wheat
- Low amount of foreign matter at destoner output
- Excessive product loss or insufficient cleaning
Solution Steps:
- Check air flow setting; optimum setting should slightly lift grain
- Check table inclination and adjust according to product type
- Check vibration frequency and amplitude
- Check feeder capacity; overloading reduces performance
- Check cleanliness of table surface; clean accumulations
- Empty and clean stone collection chamber
- Check air filter and clean if necessary
Tempering Systems Problems
Insufficient Moisture Penetration and Resting
Sensor and Instrumentation Problems
General Troubleshooting Methodology and Resources
Tempering Systems Problems
Water Dosing Problems and Calibration in Tempering Unit
Symptoms:
- Irregular or insufficient moistening
- Inconsistency in wheat moisture content
- Variability in milling quality
Solution Steps:
- Check water dosing unit; clean if there is blockage
- Check water pressure and flow
- Check spray nozzles; clean clogged nozzles
- Verify tempering unit mixer is working effectively
- Calibrate moisture sensors
- Check automatic control system program
- Verify system effectiveness by measuring difference between inlet and outlet moisture
Insufficient Moisture Penetration and Resting
Symptoms:
- Non-homogeneous particle size during milling
- Difficulty in bran and endosperm separation
- Increase in sound and vibrations from rolls
Solution Steps:
- Check resting periods (16-24 hours for hard wheat)
- Check filling ratio of tempering silos
- Measure tempering temperature; low temperature slows penetration
- Cut wheat kernel for visual inspection; moisture should be visible in kernel
- Consider switching to two-stage tempering system
- Optimize tempering parameters according to wheat type
Automation and Control Systems Troubleshooting
PLC and Control System Problems
PLC Communication and Network Connection Problems
Symptoms:
- Connection errors on HMI screen
- System inability to control remote equipment
- Data loss or delay
Solution Steps:
- Check physical network connections; replace loose or damaged cables
- Check power and connection status of network switches
- Verify device IP addresses and network settings
- Check PLC battery; low charge can cause program loss
- Check PLC CPU status (run, stop, error modes)
- Ensure communication protocols are correctly configured
- Load or update PLC program from backup
Sensor and Instrumentation Problems
Level Sensor Reading Errors and Calibration
Symptoms:
- Incorrect readings on silo or bunker level indicators
- Overfilling or empty operation conditions
- Automatic feeding problems
Solution Steps:
- Clean sensor surface to remove accumulations
- Check sensor connection cables
- Verify sensor position and direction for ultrasonic sensors
- Apply calibration procedure for capacitive sensors
- Check reflection settings for radar sensors
- Measure sensor signal value with multimeter
- Check sensor mounting point; may be affected by vibration
Flour Quality and Laboratory Troubleshooting
Flour Quality Problems
Inconsistency in Protein and Gluten Values
Symptoms:
- Fluctuations in wet gluten amount
- Variability in dough rheological properties
- Inconsistency in final product quality
Solution Steps:
- Review wheat blend and check protein ratio
- Check roll settings, especially B1 and B2 passages
- Check milling temperature in reduction system
- Review roll diagram and optimize
- Check extraction rate; high extraction affects gluten values
- Check calibration of laboratory test equipment
- Create more homogeneous wheat blend
General Troubleshooting Methodology and Resources
Systematic Troubleshooting Approach
Follow a systematic approach for effective troubleshooting:
- Define Symptoms: Clearly define the problem and note all relevant symptoms
- Collect Data: Make relevant measurements and compare with normal values
- Identify Potential Causes: Prepare a checklist starting with the most likely causes
- Test and Verify: Test each potential cause and verify results
- Implement Solution: Perform necessary actions to resolve the identified problem
- Verification: Test the system to verify the problem is resolved
- Documentation: Document the problem, cause, and solution; record for future reference
You can use the “Five Whys” (5 Why) analysis method in the troubleshooting process. This approach helps move from visible symptoms of the problem to root causes.
Documentation and Record Management
For effective failure tracking and preventive maintenance:
- Keep records including date, time, symptoms, actions taken, and results for each failure
- Perform root cause analysis for recurring problems
- Keep maintenance schedule and checklists current
- Maintain equipment failure history and change records
- Manage spare parts inventory and usage records
Conclusion
Effective troubleshooting is a fundamental element of ensuring production continuity and extending equipment life in milling and grain processing facilities. The systematic approach and practical solutions presented in this guide will help resolve common problems quickly and effectively.
For more complex problems or advanced support, you can contact the Tanış A.Ş. technical service team.