RC-120-6 Mesh Belt Tempering Furnace

Installation and wiring requirements

1. Venue requirements

1. The ground shall be leveled and hardened, with a load-bearing capacity of ≥6t. Maintenance space shall be reserved around it: ≥1.5m in front and back, and ≥1m on both sides

2. Keep away from flammable, explosive, and corrosive gases. Ensure good ventilation, and maintain an ambient temperature between 0 and 40℃

2. Electrical wiring

1. The main incoming copper cable must have a cross-sectional area of ≥185mm², and it must be provided with independent protective grounding, ensuring a grounding resistance <4Ω

2. Distinguish between the power circuits (heating, fan, transmission) and the control circuits, and route them separately for shielding

3. The fan and heating system must be interlocked with hardware: the heating circuit is prohibited from being powered on if the fan has not been started

3. Mechanical leveling

The entire machine undergoes horizontal calibration to ensure the mesh belt maintains consistent horizontal alignment, preventing deviation and material jamming.

Furnace drying process (mandatory for new furnaces or furnaces restarted after being shut down for more than 7 days)

The furnace lining contains crystalline water, which will crack and fall off if directly heated to high temperatures. Therefore, a three-stage baking process is recommended:

1. Increase the room temperature to 200℃, maintain it for 2 hours, and dry the surface free water

2. Increase the temperature from 200℃ to 400℃, maintain it for 2 hours, and then remove the fiber-bound water

3. Increase the temperature from 400℃ to 550℃, maintain it for 2 hours, and solidify the furnace lining structure

The mesh belt runs at low speed throughout the entire baking process, and the fan is kept running continuously. After the baking process is completed, the temperature naturally cools down to below 200℃ before formal production resumes.

Standard Operating Procedure

(1) Pre-startup inspection (mandatory)

1. Electrical: The main switch, control power supply, and grounding wire are intact, with no signs of aging or looseness in the wiring

2. Machinery: The mesh belt is properly tensioned, without any deviation or jamming, the oil level of the reducer is normal, and the bearing is well lubricated

3. Thermal engineering: The thermocouple is securely plugged in, the heating tube is free from disconnection, and the fan's manual turning gear operates without any jamming

4. Furnace chamber: Clean metal oxide scale and debris, ensuring no workpieces left to block the air duct

5. Safety: Reset the emergency stop button, and set the overtemperature protection value to be 30℃ higher than the process temperature

(II) Power-on and temperature rise steps

1. Turn on the main power switch → control the power switch, and the electronic control system performs a self-check and resets

2. Start the hot air circulation fan (it must be started first, as the fan cannot be heated if it is not started)

3. Start the mesh belt frequency converter, conduct a low-speed trial run of the mesh belt, confirm its forward rotation and absence of deviation, and then set the production speed

4. Set the target tempering temperature for the temperature control instrument (e.g., 420℃ for springs, 380℃ for bolts), and the overtemperature protector locks the upper limit

5. Turn on the heating switches in Zone 6 in sequence, heat up in stages, and avoid a sudden increase to full power all at once

6. Maintain the set temperature for 10-15 minutes, and only after the furnace temperature becomes uniform and stable, can materials be loaded for continuous production

(III) Continuous production operation specifications

1. The workpiece should be pre-treated for oil and rust removal. Oily workpieces are prohibited from entering the furnace to avoid carbonization, smoking, and pollution of the furnace chamber

2. Workpieces should be laid out in a single layer and must not be stacked to block the hot air, ensuring even heating

3. Match the mesh belt speed according to the tempering holding time: the higher the temperature, the longer the holding time required, and the lower the speed

4. Monitor the temperature, current, fan noise, and mesh belt operating status in real-time during operation

(IV) Normal shutdown procedure (direct power off at high temperature is strictly prohibited)

1. First, turn off all the switches in the heating zones to stop the heating output

2. Keep the fan running continuously, and only shut it down when the furnace temperature drops below 150℃ (to protect the furnace lining and fan bearings)

3. Continue to operate the mesh belt at low speed, and stop the drive after clearing the remaining workpieces in the furnace

4. Turn off the control power supply → main power supply, and clean the accumulated debris at the feed inlet and discharge outlet

5. Long-term shutdown: Keep the furnace dry and sealed, cover it for dust prevention, and rotate the mesh belt at low speed once a week

(V) Emergency shutdown (fault / fire / electric leakage)

Press the red emergency stop button to cut off the main power supply; after an emergency shutdown due to high temperature, it is prohibited to restart the fan immediately. Wait for the furnace temperature to naturally decrease before troubleshooting.

Temperature control instrument programming operation (50 process curves)

1. Press [PRG] to enter programming mode and select the curve group (1-10 groups of process storage)

2. Segment setting: temperature of temperature rise segment → temperature rise time → temperature of constant temperature segment → holding time → parameters of slow cooling segment

3. Confirm and save each segment with [SEL], and press [PRG] to exit programming after all edits are completed

4. Call preset process: Select the corresponding curve number and press a button to start automatic temperature control

5. Manual mode: Independent power adjustment for single zones, used for local temperature difference correction

VIII. Safety operation prohibitions (red lines)

1. It is strictly prohibited to turn on the heating system before starting the fan, as this may cause the heating tube to burn out and the furnace lining to overheat and be damaged

2. It is strictly prohibited to introduce flammable, explosive, or highly corrosive liquid workpieces into the furnace

3. It is forbidden to open the maintenance hatch or furnace opening under high temperature conditions to prevent burns from hot gases

4. Only certified electricians are allowed to open and maintain the electric control cabinet, and it is prohibited to touch the outer wall of the furnace during high temperature periods

5. Long-term use at temperatures exceeding 600℃ is strictly prohibited, as it will significantly shorten the lifespan of both the heating elements and the furnace lining

6. If the mesh belt is stuck, it must be powered off before handling. It is forbidden to reach in and clean while it is running

Graded maintenance procedures

1. Daily maintenance (before/after shift)

• Clean the iron oxide scraps at the inlet and outlet

• Check whether the fan's operating noise and air pressure are normal

Observe whether the temperature control display in each area is stable and if there is any temperature jump

• Check the tension of the mesh belt and make timely adjustments to the limit if it deviates

2. Weekly maintenance

• Apply high-temperature lubricating grease to the transmission chain and bearings

• Secure the electric heating terminal block and thermocouple terminal block (which are prone to loosening and sparking at high temperatures)

• Clean the furnace air duct to prevent debris from blocking the hot air circulation

3. Monthly maintenance

• Dust removal and heat dissipation for the frequency converter and control cabinet, and inspection of the working status of the contactor and SSR

• Calibrate the temperature measurement accuracy of the thermocouple and correct the temperature control deviation

• Check the oil level of the reduction gearbox, and replenish with dedicated gear oil in a timely manner if the oil is insufficient

4. Quarterly/Annual overhaul

• Check the resistance of the heating tube and replace the heating element with aged or broken wires

Check the furnace lining for any peeling or cracking, and replace the aging sealing fiber strips

• Electrical insulation test of the entire machine, and replacement of aged circuits

• Inspect the fan bearing and motor insulation, and replace the bearing if necessary