This standard specifies special safety requirements for electroslag remelting furnaces. This standard applies to electroslag remelting furnaces (hereinafter referred to as electroslag furnaces) that comply with the provisions of GB 5959.1 "General Requirements for Safety of Electric Heating Equipment Part 1". GB 5959.8-1989 Safety of Electric Heating Equipment Part 8 Special Requirements for Electroslag Remelting Furnaces GB5959.8-1989 Standard download and decompression password: www.bzxz.net

National Standard of the People's Republic of China
Safety of Electric Heating Equipment Part 8
Special Requirements for Electro-slag Remelting Furnaces
Safety in electroheat installationsPart 8: Particular requirements for electro-slag remelting furnacesGB5959. 8—89
This standard is equivalent to the international standard IEC519-8 "Safety of Electric Heating Equipment Part 8 Special Requirements for Electroslag Remelting Furnaces" (1983 edition).
1 Subject content and scope of application
This standard specifies special safety requirements for electroslag remelting furnaces. This standard applies to electroslag remelting furnaces (hereinafter referred to as electroslag furnaces) that comply with the provisions of GB5959.1 "General Requirements for Safety of Electric Heating Equipment Part 1".
2 Terminology
This standard adopts the terminology specified in Chapter 2 of GB1020 "Test Methods for Electroslag Remelting Furnaces". 3 Electrical part
3.1 High voltage
3.1.1 General requirements
To ensure safe operation, the electroslag furnace should meet the following requirements: The power supply system should be able to withstand the sudden occurrence of solid slag melting current fluctuation; a.
b.
c.
The circuit breaker should meet the frequent operation requirements specified in the design; the measurement and protection circuit should be directly grounded or grounded through an approved grounding device . 3.1.2 Closing conditions of high-voltage circuit breaker
The isolation switch has been closed;
a.
b. The setting value of the secondary voltage has been checked; c. Electroslag The furnace is ready for operation. www.bzxz.net
Note: Lights or other signals should be used to indicate that the electroslag furnace is ready to start and the circuit breaker can be closed. 3.2 Main circuit
3.2.1 The main circuit should be grounded, and the ground terminal is preferably located on the water-cooled chassis. If several furnaces are powered by the same power supply, each furnace should be individually grounded.
If the main circuit is multi-grounded, attention should be paid to the current between each ground point and the current flowing through the furnace components. 3.2.2 When any furnace is not working, its circuit should be disconnected from the power supply, but still connected to the ground. 3.2.3 The following conditions should be met before the main circuit is connected: a. The working status selection switch of the electroslag furnace is in the on position, and the control panel indicates that the furnace can be put into operation; b. The electrode and crystallizer are in the smelting position. on; the Ministry of Mechanical and Electronics Industry of the People's Republic of China approved the implementation on 1990-01-01 on 1989-02-28
c. The water-cooled chassis is in the working position;
GB5959.8—89
d． Each movable conductive contact device, especially the electrode chuck or contact cheek plate, should make good contact. For movable conductive contact devices using hydraulic or pneumatic systems, not only must the contact be good, but it must also be at least under the minimum working pressure. For mechanically operated movable conductive contact devices, they must be locked after joining. The conductive clamping mechanism of the water-cooled chassis should also meet the same requirements; e. The cooling system is connected correctly, and the flow, pressure, and temperature of the cooling water should meet the working requirements of the furnace. 3.3 Auxiliary low-voltage circuit
3.3.1 Control room
The following instructions and operations should be concentrated in the control room: cooling water flow, pressure and temperature indication of each cooling circuit; a.
b. Measurement of secondary current and voltage;
Control of certain actions that may occur during furnace melting; c.
Setting of operating parameters;
d.|| tt||Alarm;
e.
f. Emergency shutdown operation.
The control room should be located in a position where the entire furnace can be observed. The control room and the furnace should be separated as much as possible, and there should be a distance that meets the safety requirements of the electroslag furnace.
3.3.2 Emergency shutdown switch
After operating the emergency shutdown switch, the electrode should be automatically lifted to a sufficient distance away from the slag and the power supply to the furnace should be cut off, but it should not be shut down for cooling. water pump and close the cooling water circuit. 4 Mechanical part
4.1 Splash of hot metal and slag
Protective measures should be taken to prevent liquid metal and slag from splashing into the control room. Note: When the furnace is running, special attention should be paid to its safety because the crystallizer may burn through. 4.2 Vibration
Various vibrations, especially those caused by sudden fluctuations in the melting current, should not put the position of the crystallizer, the spindle or the electrode chuck in a dangerous state.
4.3 Protection against harmful heating
The electrical, mechanical and hydraulic equipment of the furnace and the connecting hoses of the cooling circuit should be protected against direct heat radiation from the slag and electrodes as well as heat convection. Heating function should also prevent the above-mentioned equipment from heating up under the action of electromagnetic fields, causing its temperature to exceed the allowable range.
For safety reasons, all metal parts under strong magnetic fields and in contact with oil should be made of non-magnetic materials and should be installed to avoid forming closed loops.
4.4 Restrictions on access to the smelting area
When the furnace is powered on, personnel are prohibited from approaching the smelting area of ??the furnace. The protection of those who must perform work on a running furnace (for example, measuring temperature, replacing electrodes) and who must work near live or hot parts should be in accordance with the requirements of Article 13.4 of GB5959.1 and in relevant standards. Specific safety measures are specified in (such as corresponding product standards) or safety regulations. 4.5 Electrode position control
The up and down movement of the electrode should be limited. Care should be taken when loading and unloading electrodes. The electrode chuck and electrode lifting mechanism should be designed to prevent the electrode from sliding down. When the lifting mechanism fails, its vertically moving parts should be able to remain in place or descend slowly. 5 Cooling circuit
5.1 Cooling of the crystallizer and water-cooled chassis
GB5959.8—89
Special protection measures should be taken to ensure that the crystallizer and water-cooled chassis are protected in the event of a power outage. Still able to cool down. 5.2 Monitoring of the cooling system
For important cooling circuits, such as crystallizers, water-cooling chassis, electrode chucks, etc., the outlet temperature and flow rate of the cooling water should be monitored, and it is best to measure the inlet temperature of the cooling water. These monitoring should be set up individually for each cooling circuit. If the above-mentioned important cooling circuit is insufficiently cooled, an alarm should be sounded or even the main circuit power should be cut off. 5.3 Design
8. The cooling water source should meet the requirements of the cooling system to prevent the parts being cooled from overheating; b. The cast or welded crystallizer should have no defects such as pores and cracks to ensure that it does not leak during operation and does not affect the heat transfer effect, ||tt ||The sealing gasket used on the crystallizer should be avoided from contact with the molten charge. c.
6 Smoke exhaust
The electroslag furnace should be equipped with smoke exhaust and purification devices. 7Others
7.1 The work area should have a clear safety door so that staff can evacuate quickly in an emergency. Entrances and exits should be marked, kept clean and clear,
7.2 Fire-resistant clothing, fire-resistant insulating gloves, protective shoes and tools, and high-temperature protective clothing that can cover the entire face and neck should be stocked in the work area. Safety covers and non-metallic safety helmets that are easily accessible. 7.3 Tools in contact with liquid metal or slag should be kept clean and dry before use. 7.4 There should be appropriate drainage facilities in the work area. 7.5 When using the liquid slag melting process, precautionary measures (measures equivalent to temperatures of 1500°C to 1750°C) should be taken to ensure personal safety.
7.6 Pressure vessels containing liquids or gases should not be placed in the working area around the furnace and control room. Additional notes:
This standard is under the jurisdiction of Xi'an Electric Furnace Research Institute. This standard is drafted by Xi'an Electric Furnace Research Institute. The main drafter of this standard is Hu Shuliang.
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