Vacuum brazing furnace operation

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Instructions

This operation procedure is applicable to vacuum brazing furnace. Meanwhile, the operation and maintenance of vacuum brazing furnace shall be carried out according to this procedure.

Basic requirements:

Operators must receive relevant training before using vacuum brazing furnace to understand the equipment’s structure, performance, operation, adjustment and basic daily maintenance requirements.

Operating rules:

3.1 Operating steps of vacuum brazing furnace:

3.1.1, instructions: when the vacuum brazing furnace boiler stop after more than 8 hours, then soldering products, must be oven, oven is in the furnace under the condition of vacuum heating to a certain temperature (700 ℃), then heat preservation, when the end of the oven, let the furnace naturally cooled to about 450 ℃, can open the oven door for brazing products.

3.1.2. Oven of vacuum brazing furnace: open power supply, water source and air valve; Start mechanical pump (slide valve pump), adjust to oven procedure; Start roots pump (vacuum must be below 4.0E2Pa; if not, open the upper Angle valve to vacuum until roots pump can be started); Open the upper Angle valve, lower Angle valve, start the diffusion pump (preheating); Heating (vacuum entering below Level E-3); Enter the heat preservation stage (diffusion pump preheating 1:30 minutes or so), close the upper Angle valve, open the main valve; End the program and turn off heating; Close the main valve, start the maintenance pump, open the maintenance pump valve, and close the lower Angle valve (the furnace temperature drops to about 450℃); Turn off the Roots pump; Open the furnace body air release valve; Open the furnace door and put the product into the furnace.

3.1.3 Vacuum brazing products: close the furnace discharge valve, open the upper Angle valve, adjust the product vacuum brazing procedure; Start roots pump (vacuum must be below 4.0E2Pa); Open the lower Angle valve, close the maintenance pump valve, close the maintenance pump; Close the Angle valve and open the main valve (vacuum up to E-1PA level); Heating (vacuum must be below 2E-2Pa); End the program and turn off heating; Close the main valve, open the maintenance pump, open the maintenance pump valve (the temperature drops to about 450℃); Close the lower Angle valve and the Roots pump; Open the furnace body air release valve; Products out of the oven; If brazing product continues, repeat brazing product operation steps.

3.1.4 Precautions for vacuum brazing: Only after the operation indicator light is on can the next operation be carried out; When the furnace: start the pump, then open the pump valve; When closing the furnace: first close the pump valve, then close the pump.

3.2 In vacuum brazing, heating can only be started when the vacuum degree is lower than 3E-3Pa.

3.3 During vacuum brazing, the vacuum brazing process shall be strictly implemented, and operators shall not change the vacuum brazing process at will; Before brazing new products, the technologist should summarize the process after trial welding, and then batch production after the process is mature.

3.4. The product temperature is below 450℃ when it comes out of the oven.

3.5 After the completion of vacuum brazing, the vacuum unit cannot be shut down immediately. First, the main valve and lower Angle valve should be closed to prevent oil return and oil oxidation. When the temperature of the diffusion pump is below 50℃, the pump valve can be closed and the pump can be stopped.

3.6 After the product comes out of the oven, if the product is no longer welded, the vacuum brazing furnace door should be closed immediately and the mechanical pump should be started; Open the upper Angle valve; Start the Roots pump to keep the furnace at 1E-1PA vacuum.

Maintenance:

4.1 Regularly check the mechanical pump and the diffusion pump. When the oil level is lower than the horizontal indicator line, it should be added in time. Especially when the oil of the diffusion pump is black, it should be replaced in time and the cooling water temperature should be checked in time, generally not exceeding 30℃.

4.2 Regularly check whether the sealing parts of vacuum brazing furnace are in good condition.

4.3 Regularly test the limit vacuum and pressure rise rate of vacuum brazing furnace, and record the test results; Regularly and thoroughly clean the furnace, pipelines and valves;

4.4 Calibrate the temperature uniformity of the brazing furnace every six months. If the temperature uniformity of the brazing furnace exceeds ±3℃, it shall be corrected in time.

4.5 If the equipment is not used for a long time, the mechanical pump should be opened every 7-10 days for about half an hour to prevent rust in the pump.

4.6, should often pay attention to the lubrication of roots pump parts, such as the oil is found to be insufficient, timely supplement.

4.7 Drain the remaining water in the chiller line, especially in winter, to prevent freezing and blocking.

V. Precautions for safe operation of vacuum brazing furnace:
5.1 Operators must undergo relevant training before using aluminum alloy vacuum brazing furnace, and only qualified to operate on duty;

5.2 Vacuum brazing equipment must be operated in accordance with the prescribed usage and procedures;

5.3 Prior to any treatment of the electrical part, the equipment or the whole electrical equipment must be disconnected from the power supply in accordance with the electrical operation regulations and local safety and accident prevention measures. Electric maintenance is strictly prohibited. The “equipment maintenance” sign must be hung during the maintenance process.

5.4 In case of sudden power cut, the lower Angle valve and the main valve should be closed immediately to prevent oil return.

5.5 When the brazing furnace is shut down, close the compressed air switch, water cooling system switch and all control switches and power main switches, so that the brazing furnace is in the state of no electricity.

5.6 During the aeration process, the vacuum brazing furnace body and the furnace door shall not stand in front of people.

5.7. When coming out of the oven after vacuum brazing, pay special attention to safety and do not stand on either side of the product.

Learn More :

High Temperature Vacuum Brazing Furnace
Low Temperature Vacuum Brazing Furnace
Aluminum Vacuum Brazing Furnace