Pit-Type Pre-Evacuated Tempering Furnace for Bright Heat Treatment

bonade This series of pre-evacuated vacuum furnace is suitable for vertical heat treatment of shaft parts and other mold steel, alloy steel, auto parts and other mechanical parts in the protection of the atmosphere under the tempering, bright annealing and copper and copper alloy bright heat treatment The Features:
Using ultra-lightweight energy-saving composite lining, energy-saving effect is remarkable;
Equipped with a special gas circulation mechanism, flow, furnace temperature uniform;
Special opening and closing structure of the lid, effectively reduce the labor intensity;
Can use advanced self-tuning PID high-precision smart table, high precision temperature control;
Equipped with electrical interlock and over-temperature protection safety devices, safe and reliable operation;
Microcomputer control cabinet can be equipped with 0.1 ~ 0.2 high-precision temperature control instruments, coupled with a special furnace structure, to meet the standard category (± 1.5 ºC) high-precision needs;
Pre-vacuuming before heating, filling the protective atmosphere to make the workpiece clean;
Furnace with hot air circulation device, furnace temperature uniformity, the atmosphere is stable;
The furnace cover is provided with an air intake interface, which can pass into the methanol cracking gas
With a vertical furnace for long rod-shaped workpiece heat treatment of industrial furnace furnace section is generally round, diameter of 0.5 to 4.5 meters, the furnace up to 30 meters deep. Long rod-shaped workpiece, such as barrel, turbine spindle, generator rotor, ship spindle and other rod-type heavy workpiece, in the pit furnace is placed vertically heating, to avoid bending deformation. The furnace furnace is located on the top of the furnace, and the workpiece is suspended vertically in the furnace by special spreader. Special lifting equipment can be fast
Pit furnace
Loading and lifting the workpiece, for the convenience of operation and reduce the height of the plant, the furnace is generally all or part of the installation in the ground. Even so, equipped with deep deep furnace furnace plant, still need to build very high. Such as the original Shanghai Electric Furnace for the second heavy machinery plant in China 1.8 meters in diameter, 30 meters deep well furnace, deep underground 33.5 meters, 150 tons of bridge crane used rail surface height of 36 meters, 42 meters. With the pit furnace, it should also have the same deep quenching cooling water tank and oil tank, as well as hair or spray cooling device.

When the workpiece is quenched, the first part of the workpiece is first immersed in the cooler, and the bottom of the workpiece is the first to be immersed, the workpiece is uneven heating, affecting the quality of quenching. The usual measure is to control the upper and lower parts of the furnace to a different temperature to compensate. Since the 1920s, the aviation industry uses a pit furnace for loading and unloading workpieces from the bottom of the furnace, heating with electric heating elements, all of which are built on the ground and Move left and right on the ground track. heating
Pit type tempering furnace
Pit type tempering furnace
After the workpiece with the furnace together to move to the tank or sink above, and then start the top of the hoist on the workpiece from the furnace through the bottom of the furnace, quickly immersed in the cooling tank cooling. The workpiece from the baked into the cooling tank into the whole process and stay in the air time is very short, so less oxidation, temperature drop, the upper and lower temperature drop is basically the same, can guarantee the quality of quenching.

Pit furnace can be used gas or liquid fuel, can also be used electric heating. In the case of gaseous fuels, there are usually a number of small-energy burners installed along the tangential direction of the inner wall of the furnace, arranged evenly in a height or in a spiral form to avoid direct flushing of the workpiece by the flame to ensure uniform temperature in the furnace. When used for low temperature tempering or oil as fuel, then in the furnace with a thin muffle wall, the combustion space and heating space separated, but the muffle wall furnace, fuel consumption.

Small kiln furnace use of electric heating, most also with a special metal muffle can be carried out gas carburizing, nitriding, carbonitriding, bright annealing and other heat treatment. In a power-efficient area, or a large-scale pit furnace that requires precise control of the furnace temperature, it is more suitable for the use of electrical energy.

Precautions

1) Check the furnace door or furnace cover next to the city limit switch, should ensure that the door or furnace lid after the start, the main circuit power.

2) Pit furnace should be used before the power connector to ensure good contact. Insulation of power cord meets requirements.

3) control the atmosphere resistance furnace equipped with gas flow meter and pressure gauge, to indicate accurate and sensitive.

4) access to the flammable atmosphere of the resistance furnace, to have the furnace temperature below 760 ° C alarm and the necessary interlock to avoid the explosion.

5) The grounding bolts of the furnace body should be firm and reliable.

6) Water-cooled well-type furnace should be installed water temperature, water pressure and flow relay, there is abnormal circumstances that cut off the main circuit power supply, and issued an alarm signal.

7) control atmosphere furnace explosion-proof safety device to be flexible and reliable.

8) outside the furnace shell exposed electric heating body to have a safe and reliable protective cover

Features

1, electric furnace with a large fan device to improve the furnace temperature uniformity;

2, electric furnace sub-district control, and further improve the furnace temperature uniformity;

3, the furnace with stainless steel guide duct;

4, the lid open and close the use of lifting or automatic hydraulic opening and closing institutions, and with a guide column to ensure that the lid open and close;

5, the furnace lid and the furnace with high temperature fiber cotton production, furnace insulation performance, energy conservation, reduce production costs;

6, no pollution, good environmental benefits