Vacuum chamber furnaces with bogie hearth
Purpose and application
In chamber electric tempering furnaces with a bogie hearth, piece billets or containers for tempering are heated. The roll-out pod is convenient for vertical loading of workpieces and unloading of finished products.
Description of construction.
Electric furnaces consist of a rigid steel frame, (chamber) the inner space of which lined with flexible thermal insulation materials.
Lining side walls are made of compressed fiber modules or ultra-lightweight fireclay bricks, including slabs. The roof is made of ceramic fiber mats.
Heaters are made in the form of spirals and put on ceramic tubes. Placed on the side and back walls of the lining.
Stove damper, when opening moves up along the guides from the electromechanical drive.
Working space form flow-forming screens, which form a zone of uniform heating. The screens are made of corrosion-resistant nickel steel, spaced from the walls with and form channels for the forced movement of the heat flux. In the lower part, openings are provided for the heated air output to the area of the support grid of the bogie hearth.
Forced convection produces heat exchange between heaters and workpieces throughout the volume. In the upper part of the frame, there are drives with impellers brought into the heating chamber. Each fan generates a gas flow from the heaters to the workpieces, which ensures uniform and accurate heating.
If it is necessary to remove vapors or smoke from the chamber, it is possible to bring out a branch pipe with a gate valve.
Roll-out under consists of a steel frame on wheel pairs in the form of a lined trolley with a bottom grate. The grates increase the level of the cage placement for convection air blowing over the surface of the Workpieces. Thermal sealing of the heating chamber and the hearth is provided by labyrinth joints of thermal insulation and a sand gate. The pod roll-out is mechanized, the movement is switched on by buttons on a wired or wireless remote control. The movement is carried out along a special rail track. The guiding tracks are made of channels, with fixation to the floor of the workshop. The stopping of the hearth flush with the front framing of the furnace is ensured by a decrease in speed at the end of the movement.
Chamber electric bogie hearth furnaces have an electronic heating control with digital temperature display. The control is carried out through powerful thyristor blocks with PWM function. To register the temperature regime in the control cabinet, a recording device "Termodat", current indicators and other necessary devices are installed.
In order to increase the safety of work, all electric furnaces are equipped with interlock switches to remove the voltage when the damper is opened. If the thermocouple is broken and the temperature is exceeded, the protection is triggered to cut off the supply voltage to the heaters. The necessary power and control equipment is mounted in the control cabinet.
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In these designs, an original design of the fan stand is used, with fixation through rubber gaskets, along the stops, does not transmit vibration to the frame. The belt drive allows you to use an electric motor with a higher speed and, accordingly, a lower power with a higher efficiency. Each chamber electric furnace, during manufacture, undergoes factory tests with adjustments to the required performance characteristics.