Simple heat treatment furnace

Abstract

The invention belongs to the technical field of rolled metal heat treatment, and particularly relates to a simple heat treatment furnace which is characterized in that a furnace body comprises a furnace bottom, a furnace shell, a temperature thermocouple and a furnace cover, the furnace shell is fixed above the furnace bottom, the furnace cover is arranged above the furnace shell, and the furnace shell is a cuboid cavity formed by splicing and welding steel plates and profile steel; the temperature thermocouple penetrates through the furnace shell side wall steel structure and extends into the closed furnace body; an aluminum silicate fiber folding block is inserted into the inner surface of the furnace shell, a fiber blanket is inserted into the aluminum silicate fiber folding block, the furnace bottom is divided into three layers, a steel plate is arranged on the lower portion, a heat preservation layer is arranged in the middle, refractory bricks are arranged on the upper portion, the heat preservation layer is laid on the steel plate, the refractory bricks are laid on the heat preservation layer, brick grooves are reserved in the top ends of the refractory bricks, and carbon-silicon heating rods are placed in the brick grooves. The temperature thermocouple is connected with the electric control structure through a compensation wire, and the carbon-silicon heating rod is connected with the electric control structure through a cable. The treatment furnace is small in occupied space, high in temperature control precision and good in temperature uniformity in the heat treatment process, and the problem that workpieces are scrapped due to the high cooling speed and the too high heating temperature is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of heat treatment of rolled materials, and in particular relates to a simple heat treatment furnace. Background Art

[0002] Special rolled materials require high-temperature heat treatment after rolling. After the heat treatment, they are qualified for use only after passing the performance test. Affected by the raw materials and rolling process of the rolled materials, improper heat treatment process can easily lead to secondary heat treatment of the rolled materials or even produce scrap, which is mainly reflected in: (1) Too fast cooling speed or improper cooling during the heat treatment process will cause cracks, especially in large-sized steel parts. Once the cracks are formed, the workpiece cannot be repaired and can only be reprocessed; (2) The heating temperature is too high, resulting in coarse austenite grains, which reduces the mechanical properties of the parts, and even causes grain boundary oxidation or melting, resulting in overburning. The overburned structure cannot be restored and can only be scrapped. Summary of the invention

[0003] The purpose of the present invention is to provide a simple heat treatment furnace to solve the problem that the workpiece is scrapped due to the fast cooling speed and the excessively high heating temperature in the existing heat treatment process.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme: A simple heat treatment furnace comprises a furnace body and an electric control structure, wherein the furnace body comprises a furnace bottom, a furnace shell, a temperature measuring thermocouple and a furnace cover, a furnace shell is fixed above the furnace bottom, a furnace cover is arranged above the furnace shell, the furnace shell is a rectangular cavity made by splicing and welding steel plates and profiled steel, the temperature measuring thermocouple extends into a closed furnace body through the furnace shell side wall steel structure; an aluminum silicate fiber folding block is inserted on the inner surface of the furnace shell, a fiber blanket is inserted on the aluminum silicate fiber folding block, the furnace bottom is divided into three layers, a steel plate is provided at the bottom, an insulation layer is provided in the middle, and refractory bricks are provided at the top, an insulation layer is laid above the steel plate, refractory bricks are laid above the insulation layer, expansion joints are reserved between the refractory bricks, brick grooves are reserved at the tops of the refractory bricks, carbon silicon heating rods are placed in the brick grooves, the temperature measuring thermocouples are connected to the electric control structure through compensation wires, and the carbon silicon heating rods are connected to the electric control structure through cables.

[0005] Preferably, insulating ceramic tubes are sheathed around both ends of the carbon silicon heating rod.

[0006] Preferably, a high temperature resistant soaking steel plate is laid above the refractory bricks.

[0007] Preferably, the electric control structure includes a main circuit and a control circuit, the main circuit includes a circuit breaker, a contactor KM, a fast-fuse protection FU, and a thyristor KS, the contactor KM includes contactors KM1, KM2, and KM3, the fast-fuse protection FU includes fast-fuse protection FU1, fast-fuse protection FU2, and fast-fuse protection FU3, the thyristor KS includes thyristor KS1, thyristor KS2, and thyristor KS3, the control circuit includes a programmable regulator, and the connection relationship of the main circuit is as follows: the external power supply is connected through three-phase incoming cables L1, L2, and L3 respectively Introduced into the upper end of the circuit breaker, the lower end of the circuit breaker is connected to the upper ends of contactors KM1, KM2 and KM3 through cables, the lower ends of contactors KM1, KM2 and KM3 are connected to the upper ends of fast-fuse protection FU1, FU2 and FU3 through cables, the lower ends of fuse protection FU1, FU2 and FU3 are connected to the incoming line ends of thyristors KS1, KS2 and KS3 through cables, the outgoing line ends of thyristors KS1, KS2 and KS3 are connected through The cable is connected to the external leakage terminal of the on-site carbon silicon heating rod on the outside of the furnace. The carbon silicon heating rod adopts a triangle connection method; the connection relationship of the control circuit is as follows: take a one-phase live wire and a one-phase neutral wire from the lower end of the circuit breaker and connect them to the upper end of the power switch Q1 through a cable, take a one-phase live wire and a one-phase neutral wire from the lower end of the contactor KM1 and connect them to the upper ends of the power switches Q2 and Q3 respectively through cables; the lower end L1 and N of the power switch Q1 are connected to the programmable regulator power terminals 11 / 12 through cables; the lower end L1 and N of the power switch Q2 are connected to the trigger power terminal 1 through cables 5 / 16; a pair of L1 and N at the lower end of the power switch Q3 is connected to the fan M through a cable, and the fan M is placed in the electric control cabinet; the 7 / 9 terminals of the programmable regulator are connected to the temperature measuring thermocouple terminal through a compensation wire, and the 14 / 15 terminals of the programmable regulator are connected to the trigger terminals 1 / 2 through a cable; the 9 / 10 terminals of the trigger are connected to the TA / GA terminals of the thyristor KS1 through a cable, and the 11 / 12 terminals are connected to the TB / GB terminals of the thyristor KS2 through a cable; the 13 / 14 terminals are connected to the TC / GC terminals of the thyristor KS3 through a cable.

[0008] Preferably, a start-stop circuit is connected between the lower end of the power switch Q1 and the programmable regulator, and between the lower end of the power switch Q2 and the trigger, and the connection relationship of the start-stop circuit is as follows: another one-phase cable is connected to one end of the normally closed contact of the stop button SA1 at the lower end of the power switch Q1, and the other end of SA1 is connected to one end of the normally open contact of the start button SA2 through a cable, and the other end of the start button SA2 is connected to one end of the normally open contact of the power switch Q3 through a cable, and the other end of the normally open contact of the power switch Q3 is connected to one end of the contactor KM1 coil through a cable, and the other end of the contactor KM1 coil is connected back to the N phase at the lower end of the power switch Q1 through a cable, and the normally open contact of the contactor KM1 coil in the self-protection circuit is connected in parallel to both ends of the normally open contact of the start button SA2 through a cable, and the running indicator light is connected in parallel to both ends of the contactor KM1 coil through a cable.

[0009] Preferably, the carbon silicon heating rod extends out of the furnace and is connected to the cable through a crimping piece.

[0010] Preferably, the furnace cover is divided into a first furnace cover and a second furnace cover. The four sides of the first furnace cover and the second furnace cover are made of 3mm thick steel plates and 100 angle steels through splicing and welding. The middle part of the first furnace cover is a 200mm thick aluminum silicate fiber folding block, and the middle part of the second furnace cover is a 200mm thick fiber blanket.

[0011] Preferably, the steel plate thickness of the furnace shell is 3 mm, and the side length of the steel section is 50 mm.

[0012] Preferably, the aluminum silicate fiber folding blocks and fiber blankets inserted on the inner surface of the furnace shell are both 300 mm.

[0013] Preferably, the steel plate thickness of the furnace cover is 3 mm, and the side length of the angle steel is 100 mm.

[0014] Working principle: After the circuit breaker is closed, the power is supplied to the control circuit switch and the upper end of the contactor KM. After the control circuit power switch Q1 is closed, the programmable regulator is powered on, and the contactor closing circuit is energized. After the start button is operated, the contactor KM1 is energized, the power switch Q2 is closed, the trigger is powered on, and the fan in the electric control cabinet is started after the power switch Q3 is closed. At the same time, the power is supplied to the upper end of the thyristor KS after passing through the fast fuse protection FU. At this time, the thyristor KS is not triggered and the circuit is not turned on; the process curve is set according to production requirements, and the process curve is set through the programmable regulator to achieve multi-stage curve setting; after the setting is completed, press the button on the programmable regulator panel to start the process. At this time, the programmable regulator outputs a 4-20 mA signal to the trigger. The programmable regulator adjusts the output size of the trigger by changing the size of the signal sent. The output size of the trigger controls the size of the thyristor KS conduction, and then controls the output current of the circuit, that is, the heating power of the carbon silicon heating rod; the temperature condition in the furnace is collected and fed back to the programmable regulator through the temperature measuring thermocouple. The programmable regulator adjusts the output signal size after comparing the set temperature with the actual temperature fed back, realizing a temperature control closed loop. When the set process is completed, heating stops automatically.

[0015] After closing the power switch Q1 / Q2 / Q3 in the start-stop circuit, the contactor KM1 coil is energized after the start button SA2 is pressed. After the coil is energized, the normally open contact of KM1 is closed, and the start button SA2 circuit is self-protected. The contactor KM1 is energized and operates normally, and the operation indicator lights at both ends of the contactor KM1 coil are on; after pressing the stop button SA1, the power supply circuit of the contactor KM1 coil is cut off, the contactor KM1 is disconnected, the normally open contacts are disconnected at the same time, the self-protection circuit is interrupted, and the control circuit remains disconnected after releasing the stop button SA1. After the contactor KM1 is disconnected, the main circuit is cut off.

[0016] Beneficial effects achieved by the present invention: (1) The porous structure and low thermal conductivity of the aluminum silicate fiber folding block and fiber blanket effectively prevent the transfer of heat in the furnace, reduce heat loss, maintain stable equipment temperature, and improve production efficiency; (2) The treatment furnace has a compact structure, occupies a small space, is easy to operate, has high temperature control accuracy, has good temperature uniformity during the heat treatment process, and has high efficiency and low energy consumption; (3) The heating power of the carbon rod is controlled by the aluminum silicate fiber folding block and fiber blanket of the furnace shell and the furnace cover in combination with the programmable regulator and thyristor in the electric control structure, so that the heating temperature will not be too high, thus avoiding the coarsening of austenite grains, and preventing the problems of grain boundary oxidation, melting or even overburning; (4) The temperature control closed loop is realized by combining the refractory bricks and insulation layer at the bottom of the furnace with the temperature measuring thermocouple and the programmable regulator to adjust the trigger. The cooling rate during the heat treatment process is appropriate to prevent cracks in the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the furnace bottom in the embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a furnace cover in an embodiment of the present invention; Figure 4 Schematic diagram of the electric control structure in an embodiment of the present invention.

[0018] Explanation of the accompanying drawings: 1. furnace body; 101. furnace bottom; 102. furnace shell; 103. temperature measuring thermocouple; 104. furnace cover; 105. steel plate; 106. insulation layer; 107. refractory bricks; 108. carbon silicon heating rod; 109. insulating ceramic tube; 110. first furnace cover; 111. second furnace cover; 112. first aluminum silicate fiber folding block; 113. first fiber blanket; 114. second aluminum silicate fiber folding block; 115. second fiber blanket; 116. high temperature resistant soaking steel plate; 2. electrical control structure. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings and embodiments.

[0020] like Figure 1-2As shown, a simple heat treatment furnace includes a furnace body 1 and an electric control structure 2. The furnace body 1 includes a furnace bottom 101, a furnace shell 102, a temperature measuring thermocouple 103 and a furnace cover 104. The furnace shell 102 is fixed above the furnace bottom 101, and the furnace cover 104 is arranged above the furnace shell 102. The furnace shell 102 is a rectangular cavity made of steel plates and steel sections spliced ​​and welded. The steel plate thickness of the furnace shell 102 is 3 mm, and the side length of the steel section is 50 mm. The temperature measuring thermocouple 103 extends into the closed furnace body through the side wall steel structure of the furnace shell 102; a second aluminum silicate fiber folding block 114 is inserted on the inner surface of the furnace shell 102, and a second fiber blanket 115 is inserted on the second aluminum silicate fiber folding block 114. The second aluminum silicate fiber folding block and the second fiber blanket are both 300 mm. The furnace bottom 101 is divided into three layers, the bottom is a steel plate 105, and the middle is an insulation layer 10 6. Refractory bricks 107 are placed on the top, an insulating layer 106 is laid on the steel plate 105, refractory bricks 107 are laid on the insulating layer 106, expansion joints are reserved between the refractory bricks 107, brick grooves are reserved on the tops of the refractory bricks 107, carbon silicon heating rods 108 are placed in the brick grooves, the temperature measuring thermocouple 103 is connected to the electric control structure 2 through a compensation wire, and the carbon silicon heating rod 108 is connected to the electric control structure 2 through a cable; the temperature condition in the furnace is collected through the temperature measuring thermocouple, and the heating power of the carbon silicon heating rod is adjusted through the electric control structure according to the temperature condition in the furnace; the parameters of the electric control structure are set according to production needs to achieve automatic control; the porous structure and low thermal conductivity coefficient inside the second aluminum silicate fiber folding block and the second fiber blanket effectively prevent the transfer of heat in the furnace, reduce heat loss, keep the equipment temperature stable, and improve production efficiency.

[0021] A further embodiment of the present invention is as follows: Figure 2 As shown, insulating ceramic tubes 109 are sleeved on both ends of the carbon silicon heating rod 108, and high temperature resistant soaking steel plates 116 are laid on top of the refractory bricks 107; the insulating ceramic tubes not only have excellent insulation effect, but also prevent leakage and avoid accidents; the high temperature soaking steel plates have high temperature stability, corrosion resistance, high strength and toughness, which makes the carbon silicon heating rod heat more evenly and improves the product qualification rate.

[0022] A further embodiment of the present invention is as follows: Figure 3 As shown, the furnace cover 104 is divided into a first furnace cover 110 and a second furnace cover 111. The first furnace cover 110 and the second furnace cover 111 are made of 3 mm thick steel plates and 100 angle steels by splicing and welding. The middle part of the first furnace cover is a 200 mm thick aluminum silicate fiber folding block 112, and the middle part of the second furnace cover is a 200 mm thick fiber blanket 113. The first aluminum silicate fiber folding block and the first fiber blanket prevent the transfer of heat in the furnace body and reduce heat loss.

[0023] A further embodiment of the present invention is as follows: Figure 4As shown, the electric control structure 2 includes a main circuit and a control circuit. The main circuit includes a circuit breaker, a contactor KM, a fast-fuse protection FU, and a thyristor KS. The contactor KM includes contactors KM1, KM2, and KM3. The fast-fuse protection FU includes fast-fuse protection FU1, fast-fuse protection FU2, and fast-fuse protection FU3. The thyristor KS includes thyristor KS1, thyristor KS2, and thyristor KS3. The control circuit includes a programmable regulator. The connection relationship of the main circuit is as follows: the external power supply is introduced into the upper end of the circuit breaker through the incoming cables L1, L2, and L3 respectively, the lower end of the circuit breaker is connected to the upper ends of the contactors KM1, KM2, and KM3 respectively through cables, and the lower ends of the contactors KM1, KM2, and KM3 are connected respectively. The cables are connected to the upper ends of the fast-fuse protection FU1, fast-fuse protection FU2 and fast-fuse protection FU3. The lower ends of the fast-fuse protection FU1, fast-fuse protection FU2 and fast-fuse protection FU3 are connected to the incoming lines of the thyristors KS1, thyristors KS2 and thyristors KS3 through cables respectively. The outgoing lines of the thyristors KS1, thyristors KS2 and thyristors KS3 are connected to the external leakage terminals of the on-site carbon silicon heating rods on the outside of the furnace through cables respectively. The carbon silicon heating rods are connected in a triangle. The connection relationship of the control circuit is as follows: take a one-phase live wire plus a one-phase neutral wire from the lower end of the circuit breaker and connect them to the upper end of the power switch Q1 through cables. Take a one-phase live wire plus a one-phase neutral wire from the lower end of the contactor KM1 and connect them to the upper ends of the power switches Q2 and Q3 through cables respectively; the lower end L1 and The N pair is connected to the power terminals 11 / 12 of the programmable regulator through cables; the L1 and N pair at the lower end of the power switch Q2 are connected to the trigger power terminals 15 / 16 through cables; the L1 and N pair at the lower end of the power switch Q3 are connected to the fan M through cables, and the fan M is placed in the electric control cabinet; the 7 / 9 terminals of the programmable regulator are connected to the temperature measuring thermocouple terminal through compensation wires, and the 14 / 15 terminals of the programmable regulator are connected to the trigger terminals 1 / 2 through cables; the 9 / 10 terminals of the trigger are connected to the TA / GA terminals of the thyristor KS1 through cables, and the 11 / 12 terminals are connected to the TB / GB terminals of the thyristor KS2 through cables; the 13 / 14 terminals are connected to the TC / GC terminals of the thyristor KS3 through cables; the lower end of the power switch Q1 The start-stop circuit is connected between the end and the programmable regulator, and the connection relationship of the start-stop circuit is as follows: another one-phase cable is connected to one end of the normally closed contact of the stop button SA1 at the lower end of the power switch Q1, and the other end of SA1 is connected to one end of the normally open contact of the start button SA2 through a cable, and the other end of the start button SA2 is connected to one end of the normally open contact of the power switch Q3 through a cable, and the other end of the normally open contact of the power switch Q3 is connected to one end of the contactor KM1 coil through a cable, and the other end of the contactor KM1 coil is connected back to the N phase at the lower end of the power switch Q1 through a cable, and the normally open contact of the contactor KM1 coil in the self-protection circuit is connected in parallel to both ends of the normally open contact of the start button SA2 through a cable, and the running indicator light is connected in parallel to both ends of the contactor KM1 coil through a cable;The heating efficiency of the carbon silicon heating rod is controlled by the thyristor KS and the programmable regulator to prevent the heating temperature from being too high, which will lead to coarse austenite grains, reduce the mechanical properties of the parts, and even cause grain boundary oxidation or melting, resulting in overburned workpieces being scrapped; the temperature measuring thermocouple and the programmable regulator adjust the trigger according to the collected temperature to automatically stop heating, thus realizing a temperature control closed loop. ;

Claims

1. A simple heat treatment furnace, characterized in that: The invention comprises a furnace body and an electric control structure, wherein the furnace body comprises a furnace bottom, a furnace shell, a temperature measuring thermocouple and a furnace cover. A furnace shell is fixed above the furnace bottom, and a furnace cover is arranged above the furnace shell. The furnace shell is a rectangular cavity made by splicing and welding steel plates and section steels. The temperature measuring thermocouple extends into the closed furnace body through the steel structure of the furnace shell side wall. An aluminum silicate fiber folding block is inserted on the inner surface of the furnace shell, and a fiber blanket is inserted on the aluminum silicate fiber folding block. The furnace bottom is divided into three layers, with a steel plate at the bottom, an insulation layer in the middle, and refractory bricks at the top. An insulation layer is laid above the steel plate, and refractory bricks are laid above the insulation layer. Expansion joints are reserved between the refractory bricks, and brick grooves are reserved at the tops of the refractory bricks. Carbon silicon heating rods are placed in the brick grooves. The temperature measuring thermocouples are connected to the electric control structure through compensation wires, and the carbon silicon heating rods are connected to the electric control structure through cables.

2. A simple heat treatment furnace according to claim 1, characterized in that: Insulating ceramic tubes are sleeved around the two ends of the carbon silicon heating rod.

3. A simple heat treatment furnace according to claim 1, characterized in that: A high temperature resistant soaking steel plate is laid on the refractory bricks.

4. A simple heat treatment furnace according to claim 1, characterized in that: The electric control structure includes a main circuit and a control circuit. The main circuit includes a circuit breaker, a contactor KM, a fast-fuse protection FU, and a thyristor KS. The contactor KM includes contactors KM1, KM2, and KM3. The fast-fuse protection FU includes fast-fuse protection FU1, fast-fuse protection FU2, and fast-fuse protection FU3. The thyristor KS includes thyristor KS1, thyristor KS2, and thyristor KS3. The control circuit includes a programmable regulator. The connection relationship of the main circuit is as follows: the external power supply is introduced into the upper end of the circuit breaker through three-phase incoming cables, and the lower end of the circuit breaker is connected to the upper ends of contactors KM1, KM2, and KM3 through cables, and the lower ends of contactors KM1, KM2, and KM3 are connected to the upper ends of fast-fuse protection FU1, fast-fuse protection FU2, and fast-fuse protection FU3 through cables. The fuse protection FU1, fast-fuse protection FU2, and fast-fuse protection FU3 are connected to the upper ends of the contactors KM1, KM2, and KM3 through cables. The lower end of the protection FU3 is connected to the incoming end of the thyristor KS1, thyristor KS2 and thyristor KS3 through cables, and the outgoing end of the thyristor KS1, thyristor KS2 and thyristor KS3 is connected to the external leakage terminal of the on-site carbon silicon heating rod on the outside of the furnace through cables. The carbon silicon heating rod adopts a triangle connection method; the connection relationship of the control circuit is as follows: take a one-phase live wire plus a one-phase neutral wire from the lower end of the circuit breaker and connect them to the upper end of the power switch Q1 through cables, take a one-phase live wire plus a one-phase neutral wire from the lower end of the contactor KM1 and connect them to the upper ends of the power switches Q2 and Q3 through cables; a pair of L1 and N at the lower end of the power switch Q1 is connected to the power terminals 11 / 12 of the programmable regulator through cables; a pair of L1 and N at the lower end of the power switch Q2 is connected to the power terminals 15 / 16 of the trigger through cables; a pair of L1 and N at the lower end of the power switch Q3 is connected to the fan M through cables, and the fan M is placed in the electric control cabinet; The 7 / 9 terminals of the programmable regulator are connected to the temperature measuring thermocouple terminal through a compensation wire, and the 14 / 15 terminals of the programmable regulator are connected to the trigger terminals 1 / 2 through a cable; The trigger 9 / 10 terminal is connected to the TA / GA terminal of the thyristor KS1 through a cable, the 11 / 12 terminal is connected to the TB / GB terminal of the thyristor KS2 through a cable; the 13 / 14 terminal is connected to the TC / GC terminal of the thyristor KS3 through a cable.

5. A simple heat treatment furnace according to claim 4, characterized in that: A start-stop circuit is connected between the lower end of the power switch Q1 and the programmable regulator, and between the lower end of the power switch Q2 and the trigger. The connection relationship of the start-stop circuit is as follows: another one-phase cable is connected to one end of the normally closed contact of the stop button SA1 at the lower end of the power switch Q1, and the other end of SA1 is connected to one end of the normally open contact of the start button SA2 through a cable, and the other end of the start button SA2 is connected to one end of the normally open contact of the power switch Q3 through a cable, and the other end of the normally open contact of the power switch Q3 is connected to one end of the contactor KM1 coil through a cable, and the other end of the contactor KM1 coil is connected back to the N phase at the lower end of the power switch Q1 through a cable, and the normally open contact of the contactor KM1 coil in the self-protection circuit is connected in parallel to both ends of the normally open contact of the start button SA2 through a cable, and the running indicator light is connected in parallel to both ends of the contactor KM1 coil through a cable.

6. A simple heat treatment furnace according to any one of claims 1 or 5, characterized in that: The carbon silicon heating rod extends out of the furnace and is connected to the cable through a crimping piece.

7. A simple heat treatment furnace according to claim 6, characterized in that: The furnace cover is divided into a first furnace cover and a second furnace cover. The first furnace cover and the second furnace cover are made of 3mm thick steel plates and 100 angle steels by splicing and welding. The middle part of the first furnace cover is a 200mm thick aluminum silicate fiber folding block, and the middle part of the second furnace cover is a 200mm thick fiber blanket.

8. The simple heat treatment furnace according to claim 1, characterized in that: The steel plate thickness of the furnace shell is 3 mm, and the side length of the steel section is 50 mm.

9. A simple heat treatment furnace according to claim 8, characterized in that: The aluminum silicate fiber folding blocks and fiber blankets inserted on the inner surface of the furnace shell are both 300 mm.

10. The simple heat treatment furnace according to claim 1, characterized in that: The steel plate thickness of the furnace cover is 3 mm, and the side length of the angle steel is 100 mm.

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