In summer, there is high temperature and humidity, condensation in the morning and evening, and a lot of rainwater. Fish feed is high in protein and oil, and is prone to mold, machine blockage, rust, and electrical short circuits when exposed to moisture. Practical measures are taken in six major areas: workshop environment, raw material storage, main engine section, conveying and cooling, electrical system, and shutdown protection.
1.The overall environment of the workshop is moisture-proof and moisture controlled
1. Ventilation and dehumidification control
High temperature and low humidity during the day: fully open the exhaust fan, roof ventilation fan, and convective ventilation through doors and windows; Close doors and windows during early morning, evening, rainy days, and rainy periods to prevent outdoor moisture from entering.
When the humidity is above 70%, turn on the industrial dehumidifier, and it is best to control the relative humidity within 60% in the workshop.
Keep the ground dry and immediately mop up any accumulated water; The cleaning of fish feed production line equipment should not be carried out with excessive water flushing. Instead, high-pressure air guns and wet cloths should be used for wiping.
2. Eliminate the formation of condensation
Cold and hot equipment (water-cooled pipes, coolers, and outer walls of chillers) are wrapped with insulation cotton to isolate temperature differences, condensation, and dripping.
Avoid direct confrontation of hot and cold air in the workshop to prevent condensation and water droplets from hanging on the inner walls of equipment and material silos.
3. Roof and wall waterproofing inspection
Inspect the gaps in roofs, windows, and through wall pipelines every week, and seal off any leaking points; Rainwater flowing along the wall will significantly increase indoor humidity, so it is necessary to repair waterproofing in a timely manner.
2. Moisture prevention in raw material warehouse and feeding section (moisture prevention at the source is of utmost importance)
Moisture in raw materials is the root cause of machine blockage and mold growth, and fish meal, soybean meal, and flour are prone to moisture absorption and clumping.
1. Raw material stacking standards
All raw materials should be placed at least 15cm off the ground and 30cm off the wall to prevent moisture from rising from the ground; Do not stack directly on the ground.
The stacking of bagged raw materials should not be too high, and ventilation channels should be left between the stacks; Cover the raw materials with rainproof tarpaulin for long-term storage.
2. Moisture proofing of the silo
Install a breathable dust cap on the top of the silo and install an insect and moisture resistant filter inside to prevent rainwater and moisture from entering; Install a vibrator on the warehouse wall to prevent wet materials from hanging and clumping on the wall.
Clear the remaining materials at the bottom of the warehouse for each shift, and prohibit overnight storage of raw materials; Dry the condensation on the warehouse wall in a timely manner and regularly clean the clumped and moldy raw materials inside the warehouse.
The large fish feed production line's raw material warehouse is equipped with a ventilation fan on the top of the warehouse, which intermittently exhausts and dehumidifies on rainy days.
3. Protection of feeding port
Install rainproof eaves in the feeding area and close the feeding port cover plate on rainy days; When feeding, avoid rainwater drifting into the mixer, and dry wet raw materials separately before use.
4. Raw material moisture control
Raw materials with excessive moisture content should be stacked separately and pre dried in advance; Strictly control the proportion of water added for quenching and tempering to reduce the moisture content of materials inside the machine.
3.Puffing/granulation host, moisture and adhesion prevention in the tempering section
Heating and tempering with steam, due to its high moisture content, can easily accumulate water and wet materials in summer when combined with high humidity in the air.
1. Drainage of conditioner
The condensate drainage pipe at the bottom of the conditioner should be kept unobstructed, and any accumulated water should be discharged during each shift; Install drain valves on steam pipelines to prevent condensation water from mixing with materials and causing wet material clumping.
2. Cleaning material inside the host
Each shift of fish feed production line is shut down to thoroughly clean the conditioning blades, expansion screw sleeves, and residual wet materials in the pelletizer mold holes; Damp and hot residue trapped in the equipment overnight can ferment and stick to the screw.
3. Steam pipeline insulation
All steam pipelines and valves are wrapped with insulation layer to reduce water droplets from the pipe wall falling into the equipment; Connect a water collection tray below the valve and regularly pour water.
4. Ring mold and pressure roller protection
After the fish feed production line is shut down, wipe the moisture in the mold holes and apply a thin layer of anti rust lubricating grease to prevent rusting and blockage of the mold holes in high humidity environments.
4.Moisture and rust prevention for cooling, screening, and conveying equipment
The counter current cooler is the area with the highest humidity in the entire fish feed production line, and the backflow of water vapor is prone to rusting equipment and returning moisture to finished products.
1. Special moisture-proof measures for counterflow coolers
The cooling fan runs continuously to ensure sufficient cooling air volume, and the temperature difference between the finished product discharge temperature and room temperature is ≤ 3 ℃, to avoid moisture and mold inside the finished product after packaging.
Drain the water tank at the bottom of the cooler every shift and clean up the accumulated wet materials; The cooling box is well sealed to prevent the backflow of outdoor moisture.
Regularly clean the damp powder in the cooling mesh and air chamber to prevent rust from penetrating the mesh.
2. Elevators, winches, and scraper conveyors
A maintenance and cleaning port is set at the bottom of the fish feed production line barrel to clean the wet powder deposited at the bottom daily, avoiding long-term moisture corrosion of the shell.
Replace the aging sealing strip of the conveyor cover plate in a timely manner to reduce the entry of workshop moisture into the machine; Wipe the chains and bearings with water vapor daily and add waterproof and rust proof lubricating grease.
3. Screening and packaging section
The top cover of the sieve is sealed to prevent moisture from falling onto the material on the sieve; The packaging station is equipped with a dehumidification fan, and the packaging bags are sealed and stored to prevent plastic bags from absorbing moisture and becoming soft.
5.Moisture and lightning protection of electrical control system (high incidence of short circuit faults in summer)
High humidity and thunderstorms can easily cause short circuits and burnout of frequency converters and motors.
1. Moisture proof control cabinet
Place industrial desiccants inside the cabinet, install a constant temperature dehumidification heater, and operate at low power for 24 hours to eliminate condensation inside the cabinet.
Check the sealing strip of the fish feed production line cabinet door and replace it immediately if it is damaged; The control cabinet should be kept away from the cooler, steam pipeline, and cleaning area.
Close the cabinet door on rainy days and prohibit opening it for ventilation; Regularly use dry compressed air to blow away dust and moisture inside the cabinet.
2. Motor and circuit protection
All motor junction boxes of the fish feed production line have intact sealing gaskets; Install rain covers on motors in outdoor/humid areas; Wrap waterproof insulation tape around cable joints.
3. Lightning protection grounding
Before thunderstorms, check the grounding resistance of the entire fish feed production line, and ensure reliable grounding of the workshop, silo, and electrical control cabinet; Disconnect the main power supply during shutdown to prevent lightning strikes from penetrating electrical components.
6. Special moisture-proof maintenance after daily shutdown of fish feed production line (key closing steps)
1. The entire fish feed production line is emptied of all internal materials of the equipment, leaving no residue overnight;
2. Wipe the condensation droplets on the outer wall of the equipment with a damp cloth, and apply anti rust grease to the metal transmission parts;
3. Close the workshop doors and windows, and turn on the workshop dehumidifier/exhaust fan for low-speed circulation;
4. All steam and cooling water valves are closed, and residual water in the pipeline is drained;
5. Long term shutdown of fish feed production line (night shift shutdown, shutdown for more than 1 day):
Open all the maintenance doors of the fish feed production line equipment for ventilation and drying;
Empty the silo;
The dehumidification heater in the electrical control cabinet is continuously powered on;
Bare screws and ring molds coated with rust proof oil.
7.Moisture proof auxiliary equipment for fish feed production line
1. Cooling tower and circulating water system
Ensure proper drainage around the water-cooled unit of the fish feed production line to prevent water accumulation from evaporating and increasing workshop humidity; Pipeline insulation to prevent condensation and dripping.
2. Bag filter
Wet dust can easily stick to cloth bags, so clean the dust every shift; Increase the frequency of clearing dust on rainy days to avoid the accumulation of damp dust and the growth of mold.
3. Boiler steam system
Regularly inspect the drain valve of the fish feed production line to reduce the production of condensed water and lower the total amount of water vapor in the workshop.
