ordinary quenching oil tank is the most widely used quenching tank, and its structure, shape and size are also various. the principles of selection and determination are mainly determined according to the output, the size of quenched workpieces, the weight of single pieces, and the working size and operating conditions of the heat treatment furnace. For small quenching oil tanks with small output, cooling water jacket structure is mostly adopted or cooling screw-shaped water pipes and serpentine pipes are installed inside the oil tank for cooling. For quenching oil tanks with large output, a circulating device for quenching medium cooling is often attached, and the heat medium is recycled back to the quenching oil tank for use.

 

The front chamber of the sealed box furnace is not only the transition zone for feeding, but also the discharge zone after quenching and slow cooling of the workpiece after heating. To be able to quench, there should be an oil tank under the front chamber. To be able to cool slowly, the top or side of the front chamber should be connected to the slow cooling chamber. During feeding, discharging, quenching and slow cooling, the material plate and the workpiece must move back and forth and up and down. The back and forth movement is completed by a push-pull material machine, and the up and down movement is completed by a lifting mechanism.

 

The front room can be divided into a slow cooling room and a special slow cooling room. The front chamber shell is a square sealed chamber formed by welding, which can be integrated with the furnace shell or quenching oil tank, or connected by bolts. The front chamber door is located in front of the front chamber, and the motor reducer drives the chain to open and close. The asbestos rope is used between the door and the frame to press against the self-weight of the door or the pressing mechanism. A fire curtain device is arranged under the door. After the front door is opened, it can be automatically ignited. When the workpiece enters or pulls out, it can prevent air from entering the furnace to cause oxidation, decarburization or explosion. When the front door is closed, the fire curtain goes out at the same time. An explosion-proof device is installed in the front room. Once the air enters and causes an explosion, the gas will leak out of the explosion-proof device to ensure safety.

 

The slow cooling chamber is located on the upper or side of the front chamber. The slow cooling chamber can be welded into a steel plate sealing interlayer, and tap water can be used for cooling, or the cooling water pipe can be installed on the inner wall on both sides of the slow cooling chamber. A fan is installed on the upper part of the slow cooling chamber to force air circulation to accelerate cooling.

 

The heating chamber is welded into a sealed structure with steel plates and connected to the front chamber. The top is equipped with a fan device to circulate the furnace gas up and down to ensure the furnace temperature and atmosphere are uniform. The top of the furnace is equipped with a thermocouple to control the temperature of the furnace body.

Electric heating radiant tubes or gas fuel heating radiant tubes are used on both sides of the furnace vertically or horizontally, which is convenient for installation and maintenance. The lining adopts impervious brick and aluminum silicate fiber composite lining. The inlet and outlet guide rail in the furnace is installed at the bottom of the furnace with silicon carbide sliding type or heat-resistant steel roller type.

The quenching device is composed of quenching oil tank, quenching lifting table, oil heater, oil stirrer, etc. The quenching oil tank is a square tank, which is formed by welding steel plates and is integrated with the front chamber and the slow cooling chamber. In order to make the workpiece meet the process requirements during quenching, in addition to the oil stirrer, the tank is also equipped with an oil heater and an oil cooler to control the oil temperature between 40 and 60 & deg; to improve the oil cooling capacity.