Heat treatment temperature control cooling furnace for long-axis alloy workpiece

Abstract

The utility model discloses a heat treatment temperature control cooling furnace for long shaft type alloy workpieces, which comprises a long cylindrical furnace body, the furnace body consists of a furnace bottom and a furnace shell, the furnace bottom is provided with an exhaust pore plate, the center of the exhaust pore plate is provided with an exhaust pipe, the middle part and the lower part of the furnace body are respectively provided with a group of annular spiral air inlet pipes, and the annular spiral air inlet pipes are communicated with the furnace shell. An air outlet of the spiral air inlet pipe is located in the furnace body and formed in the tangential direction of the furnace body, a high-voltage frequency conversion fan is arranged on an air inlet pipe of the spiral air inlet pipe, and the upper portion, the middle portion and the lower portion of a furnace shell of the furnace body are each provided with a thermocouple in an inserted mode. Compared with the prior art, the furnace body is designed for the long-axis alloy workpiece, during cooling, the upper section and the lower section of the long-axis workpiece can be rapidly cooled, in the cooling process, detection and control are conducted through the thermocouple and the temperature control instrument, and the temperature of the upper section and the temperature of the lower section of the workpiece are basically consistent in the cooling process through the high-voltage frequency conversion fan; and synchronous cooling is realized so as to meet various process requirements.

Description

Technical Field

[0001] The utility model relates to the stainless steel casting industry, in particular to a temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces. Background Art

[0002] At present, the cooling process for long-axis high-alloy steel workpieces mostly adopts natural cooling treatment with high-temperature pit furnaces. Long-axis workpieces are long and cool down slowly. Some workpieces cannot meet the cooling process requirements through natural cooling in high-temperature pit furnaces. Therefore, it is urgent to design a special temperature-controlled cooling furnace. Utility Model Content

[0003] The purpose of this utility model is to design a heat treatment temperature-controlled cooling furnace for long-axis alloy workpieces based on the characteristics of cooling long-axis workpieces, which is used to solve the above-mentioned problems and make its cooling requirements meet its cooling process.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces, comprising a long cylindrical furnace body, the furnace body consisting of a furnace bottom and a furnace shell, the furnace bottom is provided with an exhaust hole plate, the workpiece to be processed is vertically hoisted in the furnace body and placed on the exhaust hole plate, three exhaust pipes arranged in a herringbone shape are provided at the center of the exhaust hole plate, the exhaust pipes are all located in the workpiece to be processed, the middle and lower parts of the furnace body are provided with a group of annular spiral air inlet pipes, the air outlet of the spiral air inlet pipe is located in the furnace body and is opened along the tangential direction of the furnace body, the air inlet pipe of the spiral air inlet pipe is provided with a high-pressure variable frequency fan, and a group of thermocouples are inserted in the upper, middle and lower parts of the furnace shell of the furnace body. After the thermocouple is inserted, its front end is close to the surface of the workpiece to be processed.

[0005] Preferably, it further includes a high-temperature flue gas exhaust duct, one end of which is arranged at the bottom of the furnace body and connected to three exhaust pipes, and the other end extends to the ground. The high-temperature flue gas exhaust duct is provided with a high-temperature induced draft fan and an electric actuator for controlling the start and stop of the high-temperature induced draft fan.

[0006] Preferably, the furnace lining of the furnace shell is an insulation layer, the insulation layer is assembled using aluminum silicate fiber insulation modules, and a resistance belt is hung on the inner wall of the insulation layer.

[0007] Preferably, the furnace lining of the furnace bottom is composed of an upper lightweight insulation layer and a lower high-strength refractory layer, the high-strength refractory layer is built with high-strength high-alumina refractory bricks, and the lightweight insulation layer is composed of lightweight refractory bricks, aluminum silicate fibers and asbestos boards from bottom to top.

[0008] Preferably, a temperature controller is further included, the thermocouple is electrically connected to the temperature controller, and the temperature controller performs frequency control on the high-voltage variable-frequency fan.

[0009] Preferably, the top of the furnace shell is a furnace opening, and a furnace cover that can rotate and rise and fall is installed on the furnace opening.

[0010] Preferably, an anti-collision ring is provided at the upper, middle and lower parts of the furnace body respectively. The anti-collision ring is prefabricated into a refractory brick shape using high-strength castable and is divided into 24 equal parts in the circumferential direction.

[0011] Compared with the existing technology, the advantages of the present invention are as follows: the furnace body of the present invention is designed for long-axis alloy workpieces, and two sets of upper and lower spiral air inlet pipes are used for two-stage cold air cooling during cooling, which can quickly cool down the upper and lower sections of the long-axis workpiece. During the cooling process, the furnace temperature is detected and controlled by thermocouples and temperature controllers, and the frequency control of the high-voltage variable frequency fan is used to make the upper and lower sections of the workpiece basically consistent in temperature during the cooling process, achieving synchronous cooling to meet various process requirements. When the air is introduced, a spiral air intake method is used to evenly cool the surface of the workpiece. In conjunction with the exhaust of the high-temperature induced draft fan, the exhaust direction of the spiral air inlet pipe spirally rises along the outer surface of the workpiece, then enters the inner tube of the workpiece from the top of the workpiece, and finally is discharged from the exhaust pipe on the exhaust plate, thereby achieving synchronous cooling of the inside and outside of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0013] Figure 2 It is a top view of the utility model.

[0014] In the figure: 1. Furnace body; 11. Furnace shell; 12. Insulation layer; 13. Resistance belt; 2. Furnace bottom; 3. Furnace cover; 4. Exhaust plate; 5. Exhaust pipe; 6. High-temperature flue gas exhaust duct; 61. High-temperature induced draft fan; 62. Electric actuator; 7. Spiral air inlet pipe; 8. High-pressure variable frequency fan; 9. Thermocouple. DETAILED DESCRIPTION

[0015] Example: The utility model will be further described below, a temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces, see Figure 1 and Figure 2, including a long cylindrical furnace body 1, the furnace body 1 is located in the foundation pit, the furnace body 1 consists of a furnace bottom 2 and a furnace shell 11, the furnace bottom 2 is provided with an exhaust orifice plate 4, the workpiece to be processed is vertically hoisted in the furnace body 1 and placed on the exhaust orifice plate 4, three exhaust pipes 5 arranged in a triangular shape are provided at the center of the exhaust orifice plate 4, the exhaust pipes 5 are all located in the workpiece to be processed, the middle and lower parts of the furnace body 1 are provided with a group of annular spiral air inlet pipes 7, the air outlet of the spiral air inlet pipe 7 is located in the furnace body 1 and is opened along the tangential direction of the furnace body 1, and a high-pressure variable frequency fan 8 is provided on the air inlet pipe of the spiral air inlet pipe 7, and a group of thermocouples 9 are respectively inserted in the upper, middle and lower parts of the furnace shell 11 of the furnace body 1. After the thermocouple 9 is inserted, its front end is close to the surface of the workpiece to be processed. The furnace body 1 of the present invention is designed for long-axis alloy workpieces. When cooling, it uses two sets of upper and lower spiral air inlet pipes 7 to implement a two-stage cold air cooling method, which can quickly cool down the upper and lower sections of the long-axis workpiece. During the cooling process, the furnace temperature is detected and controlled by thermocouples 9 and temperature controllers. The high-voltage variable frequency fan 8 is used for frequency control to make the upper and lower sections of the workpiece have basically the same temperature during the cooling process, achieving synchronous cooling to meet various process requirements. When the air is introduced, a spiral air intake method is used to uniformly cool the surface of the workpiece. In conjunction with the exhaust of the high-temperature induced draft fan 61, the exhaust direction of the spiral air inlet pipe 7 spirals up along the outer surface of the workpiece, then enters the inner tube of the workpiece from the top of the workpiece, and finally is discharged from the exhaust pipe 5 on the exhaust plate 4, thereby achieving synchronous cooling of the inside and outside of the workpiece.

[0016] It also includes a high-temperature flue gas exhaust duct 6, one end of which is arranged at the bottom of the furnace body 1 and is connected to the three exhaust pipes 5, and the other end extends to the ground. The high-temperature flue gas exhaust duct 6 is provided with a high-temperature induced draft fan 61 and an electric actuator 62 for controlling the start and stop of the high-temperature induced draft fan 61. The high-temperature gas in the furnace body 1 is discharged through the high-temperature flue gas exhaust duct 6 to realize the cold air cooling circulation in the furnace body 1.

[0017] The furnace shell 11 is lined with a 160mm thick insulation layer 1212, which is used to insulate the furnace body 1 and isolate the temperature from the operator and external peripheral equipment. This insulation layer 1212 is assembled from aluminum silicate fiber insulation modules using a scientific and rational installation method. A 20mm thick fiber blanket is first laid flat on the surface of the furnace shell 11, followed by a 140mm fiber module. This staggered construction method employs two methods of flat stacking. This structure reduces the risk of thermal bridge short circuits. The combination of two methods of flat stacking provides excellent airtightness, and offers advantages such as durability, ease of maintenance, long service life, energy efficiency, light weight, and minimal temperature rise on the outer shell of the furnace body 1. A resistance strip 13 is attached to the inner wall of the insulation layer 1212. The resistance strip 13 converts electrical energy into thermal energy, raising the furnace interior to the desired heating temperature for heat treatment.

[0018] The furnace bottom 2's lining consists of an upper lightweight insulation layer 12 and a lower high-strength refractory layer. The high-strength refractory layer is constructed using high-strength, high-aluminum refractory bricks based on the material's load softening point. It exhibits both high-temperature mechanical strength, the ability to withstand furnace loads and thermal stresses, and the ability to maintain volume stability and adapt to thermal vibrations under high-temperature conditions. It also exhibits low thermal conductivity, low heat capacity, and low thermal expansion deformation, which reduces the heat flow rate and allows for a larger temperature gradient to be achieved by rationally determining the furnace wall thickness. The lightweight insulation layer 12 is composed, from bottom to top, of lightweight refractory bricks, aluminum silicate fiber, and asbestos board. To prevent insulation leakage, the inner surface of the furnace shell 11 is densely paved with asbestos board, and all joints are covered with water glass to ensure the longevity of the furnace bottom 2. To facilitate maintenance, all materials and bricks are standard. The quality of refractory products used in furnace construction meets the requirements of JBT4311.5-2002, and the refractory bricks at the furnace mouth meet the quality requirements of YB376-75 "Test Method for Thermal Shock Stability".

[0019] The system also includes a temperature controller, to which the thermocouple 9 is electrically connected, and which performs frequency conversion control on the high-voltage variable-frequency blower 8. The temperature controller uses an SRS3 instrument with a process curve, and the instrument directly controls the inverter speed of the high-voltage variable-frequency blower 8, thereby controlling the cooling rate.

[0020] The top of the furnace shell 11 is the furnace mouth. Since the temperature of the workpiece is high, it is inconvenient for workers to approach. A furnace cover 3 that can rotate and rise and fall is installed on the furnace mouth. The furnace cover 3 is driven by a furnace door lifting motor. When the workpiece is placed in, the furnace door is closed by the furnace door lifting motor.

[0021] To prevent long-axis workpieces from swinging too much during hoisting, three anti-collision rings are set in the extension direction of the furnace body 1, located at the upper, middle and lower parts of the furnace body 1 respectively. The anti-collision rings are used to prevent long-axis workpieces from colliding with the heating elements in the furnace when entering and exiting the furnace, thereby protecting the service life of the heating elements. The anti-collision rings are prefabricated into refractory bricks using high-strength castables and are divided into 24 equal parts in the circumferential direction. If one of them is damaged, it can be replaced separately, facilitating subsequent maintenance. The diameter of the effective working space of the furnace is Ф1600mm, the inner diameter of the furnace is Ф1900mm, and the inner diameter of the anti-collision ring is Ф1750mm, ensuring that the workpiece does not collide with the furnace wall.

[0022] The utility model is a special equipment which can be used for the cooling process of long shaft high alloy steel. It is used in conjunction with a high temperature pit furnace. Before cooling the workpiece, it is first cooled at high temperature in the high temperature pit furnace. When natural cooling cannot meet the requirements of the cooling process, the workpiece is transferred to the cooling and heat preservation barrel of the utility model for forced cooling to meet the requirements of the cooling process.

[0023] The above is a detailed introduction to a temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, based on the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. Changes and improvements to the present invention will be possible without exceeding the concept and scope specified in the appended claims. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces, characterized by: It includes a long cylindrical furnace body, which consists of a furnace bottom and a furnace shell. The furnace bottom is provided with an exhaust hole plate. The workpiece to be processed is vertically hoisted in the furnace body and placed on the exhaust hole plate. Three exhaust pipes arranged in a herringbone shape are provided at the center of the exhaust hole plate. The exhaust pipes are all located in the workpiece to be processed. A group of annular spiral air inlet pipes are provided in the middle and lower parts of the furnace body. The air outlet of the spiral air inlet pipe is located in the furnace body and is opened along the tangential direction of the furnace body. A high-pressure variable frequency fan is provided on the air inlet pipe of the spiral air inlet pipe. A group of thermocouples are respectively inserted in the upper, middle and lower parts of the furnace shell of the furnace body. After the thermocouples are inserted, their front ends are tightly attached to the surface of the workpiece to be processed.

2. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: It also includes a high-temperature flue gas exhaust duct, one end of which is arranged at the bottom of the furnace body and connected to three exhaust pipes, and the other end extends to the ground. The high-temperature flue gas exhaust duct is provided with a high-temperature induced draft fan and an electric actuator for controlling the start and stop of the high-temperature induced draft fan.

3. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: The furnace lining of the furnace shell is a thermal insulation layer, which is assembled from aluminum silicate fiber thermal insulation modules. A resistance belt is hung on the inner wall of the thermal insulation layer.

4. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: The furnace lining consists of an upper lightweight insulation layer and a lower high-strength refractory layer. The high-strength refractory layer is built with high-strength high-aluminum refractory bricks. The lightweight insulation layer consists of lightweight refractory bricks, aluminum silicate fibers and asbestos boards from bottom to top.

5. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: It also includes a temperature controller, the thermocouple is connected to the temperature controller via an electrical signal, and the temperature controller performs frequency conversion control on the high-voltage variable frequency fan.

6. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: The top of the furnace shell is a furnace opening, and a rotatable and liftable furnace cover is installed on the furnace opening.

7. The temperature-controlled cooling furnace for heat treatment of long-axis alloy workpieces according to claim 1, characterized in that: An anti-collision ring is respectively provided at the upper, middle and lower parts of the furnace body. The anti-collision ring is prefabricated into a refractory brick shape using high-strength castable material and is divided into 24 equal parts in the circumferential direction.

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