| Furnace shell | The furnace type is vertical type or horizontal type and the inner layer is a cylinder made of 1Cr18Ni9, and the outer casing is made of carbon steel by anti-rust treatment. A jacket formed between the two layers can be cooled by water to carry away the heat transferred to the inner wall of the furnace shell. The inner and outer cylinders are welded integrally with the upper and lower flanges, and the air suction holes, the thermocouple holes and the observation holes are opened in the middle. |
| Furnace door | The upper part of the furnace body is a furnace cover. It is welded with inner and outer sealing heads and flanges. The middle of the furnace can be cooled by water. The explosion-proof device and locking device are installed. The locking is released and the furnace cover is automatically opened backwards. When the maximum is reached, the workpiece can be loaded and unloaded. |
| Furnace bottom | The bottom part of the furnace is also composed of inner and outer heads and flanges. The middle part is cooled by water and fixed in the lower part of the furnace body. Electrodes are introduced and the electrodes are cooled by water. |
| Heating element&heat shield | It is made of high-purity graphite into a cylindrical structure. The heat shield adopts graphite tube, graphite felt and soft carbon felt. It has uniform heating, large radiation surface, good thermal shock resistance and rapid heating. The external 1Cr18Ni9 stainless steel frame is fixed and supported, and the bottom heat shield is composed of graphite. |
| Vacuum system | It is composed of a mechanical pump, a diffusion pump and a vacuum valve. The vacuum valve is a pneumatic flapper valve, and the vacuum measurement uses a digital display resistance vacuum gauge. |
| Electric system | It adopts thyristor voltage regulator control, cabinet shape and Shanghai Buco touch screen to establish a temperature and vacuum database, which clearly reflects the situation inside the furnace, neat and beautiful. The control system adopts programmable logic controller (PLC+temperature module) to realize automatic control without instrument. The electrical components are branded by OMRON. The operation modes are manual and automatic. It can be optional. It can be artificial according to user's process requirements and equipment requirements. Set up, no need to manually switch, high temperature control accuracy, easy to operate. |
| Water-cooling system | The cooling water enters through the main pipe and is sent to the furnace shell, the furnace cover, the bottom of the furnace, the electrode, the Roots pump and the direct pump, etc., through the respective branches, and then is cooled to the water tank. Each channel of cooling water has a manual valve that can be adjusted as needed. An electric contact pressure gauge is arranged on the inlet pipe, and when the water pressure is lower than 0.1 MPa, the heater can be automatically cut off. (The unit price not including water chiller.if you need need ,please see optional spares. We can help you to buy it.) |
| Installation | The place where the electric furnace is installed should meet the requirements of vacuum hygiene. The surrounding air should be clean and dry, and have good ventilation conditions. It is not easy to raise dust in the work site.
1. Check that all parts and accessories in the control cabinet are complete and in good condition.
2. The control cabinet is mounted on the corresponding foundation and fixed.
3. Connect the wiring diagram and refer to the electrical schematic diagram to connect the external main circuit and control circuit, and ground them reliably to ensure the wiring is correct.
4. Check that the movable part of the appliance should be freely movable and there is no jam.
5. The insulation resistance should be no less than 2 megohms.
6. Each valve of the vacuum furnace must be in the closed position.
7. Control the power switch to be placed in the off position.
8. Turn the head counterclockwise by the manual pressure adjustment knob.
9. The alarm button is placed in the open position.
10. According to the plan to complete the circulating cooling water connection of the equipment, it is recommended that the user connect a spare water (available tap water) at the total inlet and outlet of the equipment to prevent the circulating water from being damaged or the power failure causing the sealing ring to burn out. |
Equipment commissioning
| 1. According to the equipment floor plan, put the equipment in place, connect all the vacuum lines and valves. Note that the direct-coupled pump is best to be ground-fixed or the four-corner cushion damping rubber plate is used for shock absorption. Check whether all the accessories match the delivery list. .
2. Inform the user to complete the connection of water, electricity, and air pump users should be ready in time.
3. Connect the relevant external facility power cords. After power-on, check whether the meter shows, the steering of the direct-connected pump is correct, and whether the pneumatic valve works normally. It is best to take a vacuum first and wait for the next day to check for leaks.
4. Open the furnace cover, put the insulation layer into the furnace, adjust its height and neutrality, and observe whether the positions of the three holes around the furnace body are correct. Otherwise it should be adjusted.
5. Place the graphite electrode and graphite ring to adjust the center and height position. Test the graphite heating element and insulation screen. After everything is correct, the heating element can be processed. After placing the heating element, insulation layer, etc., measure the insulation with the furnace shell. Try the manual heating for a short time (the time should not be too long, the power should not be too large) whether the meter is normal. |
Whether the thermocouple automatically enters and exits is normal.
| 1. Before power-on, check each switch in the (off) position, the heating mode is "manual", and the power adjustment is counterclockwise to the head (lower end).
2. Control power on: Start the direct pump and Roots pump according to the sequence of process requirements.
3. Vacuum measurement in the furnace: According to the operation of the vacuum gauge, the heating can be heated when the required vacuum is reached.
4. Manual temperature rise: firstly increase the temperature by 200 °C below the furnace temperature, otherwise the temperature control is not allowed. Press the heating start button under vacuum to slowly adjust the manual power adjustment (clockwise direction) to make the current rise slowly. Do not exceed the secondary rated current of 870A, and the furnace temperature will rise. The room temperature is -2000 ° C, and the temperature can be automatically controlled by a thermocouple.
5. Cool down to control the cooling according to the preset program, or directly turn off the heating to let it cool down. However, water is not allowed to stop during the cooling process, otherwise the furnace seal will burn out.
6. The appearance of the electric furnace should be kept clean and tidy. If it is not used, the vacuum should be maintained. Otherwise, the next time it is used, the vacuuming efficiency will be reduced. Vacuum furnace and vacuum system should be used to fill the axial sealing part with vacuum sealing grease for about half a year. The axial sealing refers to the observation window baffle seat and pneumatic vacuum valve.
7. The observation window glass of the vacuum furnace should be removed and cleaned after using a furnace, and can be assembled and disassembled according to the drawings.
8. If it is found that the direct pump does not rotate normally after pressing the start button, it is generally protected by motor overload. Open the control cabinet to observe whether the thermal protector is overload protected. The schematic diagram of the thermal protector is shown in the figure, such as automatic protection. , press the RESET button to release. It is normal to start the direct pump again.
9. The user should prepare his own enamel. In order to improve the accuracy of the sintering temperature, it is best to use a 5-10 mm high graphite block sorghum at the bottom. |
| Precautions | 1. The thermocouple is a tungsten-rhenium type. When used, it will become brittle and cannot be touched. If it is damaged, it should be replaced in time. Its model is W2.
2. Winter should pay attention to the problem of warming the circulating water, otherwise it will easily burst.
3. After use, the furnace body should be kept vacuum, because the insulation layer in the furnace is easy to get wet, so keep the vacuum so that the next vacuum will be faster.
4. The graphite heating element is brittle. Be careful when placing the enamel and disassembling the insulation layer, otherwise the heating element will be damaged.
5. This equipment is more complicated. It is recommended to use it by special person. It is responsible for the strict use of pre-existing training for novices. After use, it must be recorded and used. |
