A Pre-Season Changeover Routine for a Grain Cleaning Line

A cleaning line rarely fails because it wore out. It fails because a loose bolt, a slack screen, a blocked spout or a loaded filter was left alone through the busy period. The purpose of a pre-season changeover is to find those things while the line is stopped and the calendar still allows a repair, and to leave a baseline that makes the next fault visible early.

Work in a fixed order: clean, inspect, lubricate, then the electrical and dust systems, then run. Cleaning before inspection is not housekeeping. A dusty machine hides cracks, wear and loose fasteners, and an inspector who cannot see will sign the sheet and move on.

Isolation, emptying and cleaning come before inspection

1. Isolate the supply to the whole line, lock it out and verify the voltage is absent before anyone opens a guard or reaches into a machine. Confirm that stored energy is released: gravity, springs, suspended loads and compressed air.
2. Empty the line. Run the material out, then clear spouts, hoppers, elevator boots, decks and dust hoppers by hand.
3. Clean dry. Remove dust from frames, motor covers, the outside of the control cabinet, duct runs and filter housings, and note where the heaviest build-up was. That location is a symptom, not just dirt.
4. Inspect with light and by touch, and record findings before repairing them. A note made during the inspection is worth more than one written afterwards.

Mechanical items, screens and cleaning devices

Work through the line in the direction of material flow. Nothing gets skipped and every check follows the material from one stage to the next.

• Structure and welds. Look for cracked welds, fretting marks and paint cracked along a joint on vibrating bodies and their supports. Cracks begin at the stiffest point, so examine brackets and weld toes rather than flat panels.
• Fasteners. Check the screen body, the drive mount, the motor base, the elevator frame and the anchor bolts. Vibration relaxes preload over time, so a bolt that is tight now can be loose within a month of continuous running.
• Screens. Look for holes, lifted edges, worn clamp strips, worn edge binding and deformed frames. Re-tension progressively and evenly on both sides rather than pulling one side fully, and confirm the tensioning method against the machine documentation.
• Cleaning devices. Take out the balls or bouncing elements and check diameter, shape and count. A worn ball still looks like a ball but no longer bounces, and this is the least visible cause of recurring blinding. Check the retaining plates and the space between ball and deck as well.
• Drives. Check chains for elongation, sprockets for tooth wear, belts for tension, alignment and glazing, and pulleys for runout. Replace chains and sprockets as a set rather than mixing new parts with worn ones.
• Bearings and seals. Listen, check play and look at the seals. Dust entering through a failed seal is the usual route to early bearing failure, and adding grease does not repair a torn seal.
• Spouts, transitions and liners. Wear concentrates at bends, impact points and transitions. Measure liner thickness against your previous records rather than judging by eye, and look inside bends where a thin wall is about to break through.
• Conveyors and elevators. Check belt tracking, roller condition, pulley lagging, bucket condition, chain or belt tension, and material build-up in the boot.
• Magnets. Clean the magnet faces and confirm each one sits where the material actually flows. A magnet left uncleaned loses holding force, and the failure is discovered when tramp metal reaches a deck or a downstream machine.

Keep a wear record for every item on this list rather than a pass mark. A measured value compared with the previous one gives a wear rate, and a wear rate lets you place the replacement into a planned stop instead of discovering it during the campaign.

Lubrication and drives

• Follow the lubrication points and the lubricant given in the machine documentation. Do not substitute by habit or by what happens to be on the shelf.
• Clean around each grease point before connecting the gun. Pushing dust into a bearing while greasing is a common way to shorten its life.
• Read the evidence: dry running marks, discoloured or hardened grease, grease that will not go in, or grease escaping at a seal.
• Confirm that guards and covers are back in place and secure before the run. A guard left off during inspection is a hazard that outlives the inspection.

Electrical, dust collection and instrumentation

All electrical work is carried out by a licensed electrician with the supply isolated, locked out and the voltage verified at the point of work. Do not open the control cabinet or touch wiring unless you are that person.

• Inside the cabinet: remove dust, look for signs of damp and condensation, re-tighten terminals, inspect contactor and relay contact condition, and check for discoloured or heat-marked connections.
• Verify that protection settings match the drawings and the machine documentation, and record them. A protection value changed to stop a nuisance trip usually hides a fault that returns later.
• Test the interlocks, emergency stops and level or blockage monitoring devices rather than looking at them.
• On the dust system: check filter media condition, the cleaning mechanism, the differential pressure reading, the discharge device and the ducting for settled dust. Look at the duct runs as well as the filter, because a partly filled horizontal run reduces air volume without showing on any indicator.
• Check instruments against their expected readings and record them: current, bearing temperature, differential pressure and level indications. An instrument that has drifted makes every later inspection judgement unreliable.

Run it empty, run it loaded, then write the baseline

The changeover is not finished when the last cover goes back on. It is finished when the line has been run and the numbers have been written down.

1. Run without feed and listen. Confirm rotation directions, check for abnormal noise or rubbing, confirm the guards are secure and confirm the emergency stops operate.
2. Introduce feed gradually and watch the material rather than the machine: full-width distribution on the decks, steady travel, the light fraction carrying what it should and nothing it should not, and clean discharge from every spout.
3. Re-check tension and fasteners after the initial running period. Newly tensioned decks and newly tightened fasteners settle.
4. Record the baseline: bearing temperatures at fixed points, drive current, throughput, ambient and material condition, and how the line sounds and feels. Later judgement is a comparison against this baseline, so a baseline taken casually is worse than none.
5. Confirm spare parts against your own wear list: decks in the sizes you run, cleaning devices, drive belts or chains, bearings and seals, buckets, fasteners and filter media. A found fault stays a small problem when the part is on the shelf.
6. Write the end-of-season routine as well. Work deferred from one season is discovered at the start of the next, when there is no time to fix it.

For machines that stand idle between seasons, add a wet and cold weather check to the same routine: condensation inside the cabinet, water in ducts, stiff bearings, material left in hoppers and belt or deck parts that have taken a set.

Work inside the control panel or on wiring is for a licensed electrician with the supply isolated, locked out and the voltage verified. Protection settings, capacities and acceptance figures are those of the machine documentation and the contract technical agreement.