1、 Daily cleaning: prevent starch residue and bacterial growth

1. Instant cleaning (after each batch of production)
   • Leakage ladle (forming mold) cleaning：
     • Rinse the inner wall of the leaking ladle with 40-50 ℃ warm water (to avoid starch gelatinization and adhesion caused by high temperature) to remove residual starch paste;
     • Use a soft bristled brush (such as a bristle brush) to clean the leakage holes (usually 1-3mm in diameter) to prevent blockage (if the leakage holes are blocked, the powder strips will break or have uneven thickness);
     • Soaking disinfection: Soak the leaking ladle in a 0.1% sodium hypochlorite solution for 10 minutes to kill microorganisms such as Escherichia coli (starch residue can easily breed mold, such as aflatoxin).
   • Cleaning of cooking pot (maturation tank)：
     • Drain the hot water (temperature ≥ 95 ℃) from the boiling pot, rinse the inner wall with a high-pressure water gun (pressure ≤ 0.3MPa), and remove the adhered powder stick debris;
     • Check if there is scale (such as calcium carbonate deposition) on the surface of the heating tube. If the thickness is greater than 1mm, it needs to be cleaned with citric acid solution (concentration 10%) for 2 hours.
2. Deep cleaning (after daily production)
   • Cleaning of transmission system：
     • Blow the starch dust on the surface of the motor and reducer with compressed air (pressure 0.5-0.7MPa) (the dust concentration should be controlled below 25% of the lower explosive limit);
     • Check if the drive belt (such as V-belt) is contaminated with oil, and if so, use non-woven fabric dipped in isopropanol to wipe it (avoid using gasoline, which may cause a fire).
   • Maintenance of conveyor chain plate：
     • Disassemble the chain plate (requires 2 people to cooperate to prevent deformation), soak it in hot water (60 ℃) for 10 minutes, and then scrub to remove oil stains and starch;
     • After drying, apply food grade grease (such as NLGI 0) to reduce running friction (chain plate sticking can cause the powder strip to break).

2、 Key component maintenance: extending equipment lifespan

1. Leakage maintenance
   • Material Inspection：
     • Traditional copper ladles require quarterly inspection of the surface oxide layer (copper green can contaminate the powder strip), and if it occurs, it needs to be sanded with sandpaper (mesh size ≥ 800) and coated with food grade rust proof oil;
     • Stainless steel leakage ladle needs to be inspected for cracks at the weld seam (starch corrosion may cause stress cracking), and if so, welding repair is required (welding materials must comply with GB/T 983 standard).
   • Leakage calibration：
     • Every six months, use a laser hole gauge to detect the diameter of the leakage hole, with an error of ≤± 0.1mm (leakage deviation can cause uneven thickness of the powder strip);
     • If the leakage hole wears out and expands, the leakage ladle needs to be replaced (cost about 200-500 yuan/piece, depending on the material and specifications).
2. Maintenance of Boiler Heating System
   • Heating tube inspection：
     • Use a megohmmeter to check the insulation resistance of the heating tube every month (the insulation resistance should be ≥ 1M Ω when the rated voltage is 220V). If it is lower than the standard, it needs to be replaced (the heating tube power is usually 3-6kW, and the service life is about 2000 hours);
     • Check if the wiring terminals of the heating tube are loose (looseness can increase contact resistance and cause a fire), and tighten them with a torque wrench (refer to the equipment manual for torque values, such as 8-10N · m for M6 bolts).
   • Temperature controller calibration：
     • Calibrate the temperature controller with a standard thermometer (such as a platinum resistance thermometer, with an accuracy of ± 0.1 ℃) every quarter, with an error of ≤± 1 ℃ (temperature deviation can cause insufficient or excessive ripening of the noodles, affecting the taste);
     • If the calibration exceeds the tolerance, the PID parameters of the temperature controller need to be adjusted (such as P=50, I=300, D=100, the specific parameters need to be determined according to the equipment model test).
3. Lubrication of transmission components
   • Gearbox maintenance：
     • Replace the lubricating oil every 500 hours (before replacement, empty the old oil and clean the oil tank (rinse with diesel and air dry);
     • Check the oil level (between the upper and lower limits of the oil gauge), and if the oil level is too low, it needs to be replenished (insufficient oil can lead to increased gear wear).
   • bearing lubrication：
     • Add lithium based grease (such as NLGI No.2) to the stirring shaft bearing every 200 hours, and the amount of grease added should be controlled at 1/3-1/2 of the bearing chamber (excessive amount can cause grease overflow and contaminate the powder strip);
     • Add lubricating oil (such as 32 # mechanical oil) to the conveyor chain plate bearings every month with an oil gun, and run for 10 minutes to ensure even oil distribution.

3、 Fault prevention: reduce downtime risk

1. Common faults and preventive measures

   Fault phenomenon	Possible reasons	preventive measures
   Leakage of ladle and dripping of slurry	Insufficient viscosity of starch paste and blockage of leakage holes	Adjust the starch paste formula (increase the gel agent such as konjac flour by 0.5%), regularly clean the leak (dredge it with a needle every 2 hours)
   Broken noodles	The temperature of the cooking pot is too low, and the speed of the conveyor chain plate is too fast	Control the temperature of the cooking pot to 95-98 ℃ and adjust the speed of the chain plate (matching the discharge speed of the leaking ladle, with an error of ≤ 5%)
   Heating tube burned out	Dry burning and voltage fluctuations	Install water level sensor (to prevent waterless heating), equipped with voltage regulator (voltage fluctuation ≤ ± 5%)
   Abnormal vibration of equipment	Loose transmission belt, loose foundation	Check the tension of the drive belt every month (measured with a tension meter, with an allowable deviation of ± 5%), tighten the foundation bolts (torque must meet the requirements of the equipment manual)

2. Preventive Maintenance Plan

   • Monthly maintenanceCheck the wear of the drive belt (replace if there are cracks or elongation>5%), clean the dust on the motor cooling fan;
   • Quarterly maintenanceReplace the filter element of the reducer respirator (to prevent moisture from entering), check the insulation resistance of the electrical circuit (≥ 1M Ω);
   • annual maintenanceOverhaul equipment (disassemble and clean all components, replace vulnerable parts such as seals and bearings), and perform ultrasonic cleaning on leaking ladles (remove tiny starch residues).

4、 Safe operation: Avoid personal injury and equipment damage

1. Pre-operation check
   • protective device：
     • Check if the protective cover for the leaking ladle is intact (to prevent injury from splashing high-temperature starch paste), and if the locking device for the pot lid is sensitive (to avoid accidental opening of the lid during operation);
     • Confirm that the emergency stop button (E-Stop) can be triggered normally (the equipment should stop within 3 seconds after being pressed).
   • Electrical safety：
     • Check if the power cord is damaged (if the skin cracks, it needs to be replaced), and if the grounding wire is reliably connected (grounding resistance ≤ 4 Ω);
     • The distribution box needs to be equipped with a leakage protector (operating current ≤ 30mA, operating time ≤ 0.1s), and the sensitivity should be tested once a month.
2. Precautions during operation
   • Prohibited matters：
     • It is strictly prohibited to clean the leaking ladle directly by hand (high-temperature starch paste can cause burns, special tools such as wooden shovels are needed);
     • It is strictly prohibited to open the pot lid or touch the heating tube (surface temperature can reach 150 ℃ or above) while the equipment is running.
   • Temperature monitoring：
     • The temperature of the cooking pot needs to be displayed in real time (such as a digital thermometer). If the temperature is abnormal (>100 ℃ or<90 ℃), the machine should be stopped immediately for inspection;
     • The temperature of starch paste needs to be controlled at 60-70 ℃ (too low can cause leakage and dripping, while too high can accelerate starch aging).
3. Post operation processing
   • power outage operation：
     • After turning off the device power, wait for 10 minutes for the heating tube to cool down (to avoid residual heat causing a fire);
     • Hang a warning sign that reads' No Closing '(to prevent others from making mistakes).
   • Tool return to position：
     • Store cleaning tools (such as brushes and wooden shovels) in designated locations to avoid leaving them inside the equipment and causing malfunctions during the next start-up.