Annealing pool for heat treatment of pig iron castings

Abstract

The utility model discloses an annealing pool for heat treatment of pig iron castings, and belongs to the technical field of heat treatment annealing. An annealing pool for heat treatment of pig iron castings comprises an outer cavity and an electric heater and further comprises a first protective door, a protective bin is arranged on the side face of the first protective door, a second protective door is arranged in the protective bin, a heat preservation layer is arranged in the outer cavity, an inner cavity is formed in the heat preservation layer, and a cooling air inlet is formed in the upper portion of the inner cavity. And the electric heater is mounted in the inner cavity. In order to solve the problems that the atmosphere is difficult to uniformly distribute in the whole inner cavity, so that partial area of the surface of a casting is overheated or does not reach the required heat treatment temperature, and the performance of the casting is uneven, nitrogen is injected into the inner cavity, meanwhile, a fan sucks away air in the inner cavity, and when the nitrogen content reaches a set value, the fan below the inner cavity is started; and the nitrogen is forced to flow in the sealed inner cavity, so that the purpose of uniform atmosphere is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat treatment annealing, in particular to an annealing pool for heat treatment of pig iron castings. Background Art

[0002] Annealing is a method to solve the defects of pig iron castings. Annealing refers to the process of heating and cooling to rearrange the internal structure of the casting, reduce defects, and improve the strength and toughness of the casting.

[0003] A Chinese patent with publication number CN218115505U discloses a casting annealing treatment device, which drives a rotating rod to rotate by turning on a motor. When the rotating rod rotates, it drives a fixed rotating cage to rotate, so that the casting inside the fixed rotating cage is continuously in a rotating state to perform uniform heat treatment, thereby avoiding the problem of quality reduction of the casting due to uneven heating during the annealing process.

[0004] In the above patent, the atmosphere is difficult to be evenly distributed in the entire inner cavity, which causes some areas on the surface of the casting to be overheated or fail to reach the required heat treatment temperature, resulting in uneven casting performance. Utility Model Content

[0005] The utility model aims to provide an annealing pool for heat treatment of pig iron castings, wherein a heat-insulating layer is arranged inside an outer cavity, an inner cavity is arranged inside the heat-insulating layer, a protective door and a protective chamber are arranged on one side of the inner cavity, and when the protective door is closed, the protective chamber is in a sealed state, so that the inner cavity is in a sealed state, and nitrogen is injected into the inner cavity through a nitrogen inlet, and at the same time, a fan draws air in the inner cavity from a circulating air outlet, and when the nitrogen content in the inner cavity reaches a set value, the circulating air outlet is closed and the fan under the inner cavity is started, so that the nitrogen is forced to flow in the inner cavity, and finally the purpose of uniform nitrogen atmosphere is achieved, and the problems in the prior art can be solved.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an annealing pool for heat treatment of pig iron castings, comprising an outer cavity and an electric heater, and also comprising a first protective door, a protective bin is arranged on the side of the first protective door, a second protective door is arranged inside the protective bin, a thermal insulation layer is arranged inside the outer cavity, an inner cavity is arranged inside the thermal insulation layer, a cooling air inlet is arranged above the inner cavity, a cooling air duct is arranged at one end of the cooling air inlet, a nitrogen inlet is arranged at one end of the outer cavity, a circulating air outlet is arranged at the other end of the outer cavity, a circulating air inlet is arranged below the outer cavity, a plurality of circulating air ducts are arranged on the surface of the circulating air inlet, the circulating air duct is connected to the interior of the inner cavity, a fan is arranged inside the circulating air duct, and the electric heater is installed inside the inner cavity.

[0007] Preferably, the outer cavity, the insulation layer and the inner cavity are all hollow cylindrical structures.

[0008] Preferably, the first protective door is connected to the protective chamber by a hinge, an insulation layer is provided inside the second protective door, and handles are provided on the sides of the first protective door and the second protective door.

[0009] Preferably, the protective chamber is in a sealed state after being closed, and an inert gas pipeline is externally connected to the protective chamber.

[0010] Preferably, the nitrogen inlet is communicated with the interior of the inner cavity, a nitrogen bin is provided at one end of the nitrogen inlet, and a heating coil is provided inside the nitrogen bin.

[0011] Preferably, the circulating air outlet is communicated with the interior of the inner cavity, and one end of the circulating air outlet is connected to the fan.

[0012] Preferably, a cast iron casting is provided inside the inner cavity, a placement platform is provided below the cast iron casting, a roller is provided below the placement platform, a track is provided below the roller, and a grille is provided below the track.

[0013] Preferably, the track extends from the inside of the inner cavity to the inside of the protective compartment, and the second protective door is connected to the track via a slider.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. The utility model optimizes the space required for heating during annealing operation and reduces energy waste by designing the outer cavity, the insulation layer and the inner cavity as hollow cylindrical structures. Compared with the traditional cubic structure with the same length and width, a protective door and a protective chamber are provided on one side of the inner cavity. When the protective door is closed, the protective chamber is sealed, so that the inner cavity is in a sealed state. When inert gas is filled into the protective chamber, the protective chamber can play a heat-insulating function, which helps to reduce the heat diffusion in the inner cavity.

[0016] 2. The utility model is provided with a nitrogen bin at one end of the nitrogen inlet, and a heating coil is provided inside the nitrogen bin. When the heating coil is energized, the nitrogen in the nitrogen bin is heated, and the heated nitrogen is then filled into the inner cavity, thereby avoiding the situation where a temperature difference between the nitrogen and the inner cavity affects the annealing effect; at the same time, the nitrogen inlet injects nitrogen into the inner cavity, and at the same time, the fan draws the air in the inner cavity from the circulating air outlet. When the nitrogen content in the inner cavity reaches a set value, the circulating air outlet is closed and the fan under the inner cavity is started, forcing the nitrogen to flow in the sealed inner cavity, and finally achieving the purpose of uniform nitrogen atmosphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the overall front view of the utility model;

[0018] Figure 2 It is an overall cross-sectional view of the utility model;

[0019] Figure 3 This is a schematic diagram of the cooling air duct structure of the utility model;

[0020] Figure 4 It is a schematic diagram of the placement platform structure of the utility model.

[0021] In the figure: 1, outer cavity; 101, insulation layer; 102, inner cavity; 2, first protective door; 201, protective chamber; 202, second protective door; 203, handle; 3, cooling air inlet; 301, cooling air duct; 4, nitrogen inlet; 401, nitrogen chamber; 402, heating coil; 5, circulating air outlet; 501, fan; 6, circulating air inlet; 601, circulating air duct; 602, fan; 7, electric heater; 8, track; 801, grille; 9, placement platform; 901, roller; 10, pig iron casting. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In order to solve the problem that the atmosphere is difficult to be evenly distributed throughout the inner cavity, which causes some areas of the casting surface to overheat or fail to reach the required heat treatment temperature, resulting in uneven casting performance, please refer to Figure 1-4 , an embodiment provided by the utility model:

[0024] An annealing pool for heat treatment of pig iron castings comprises an outer cavity 1 and an electric heater 7, and also comprises a first protective door 2, a protective chamber 201 is arranged on the side of the first protective door 2, a second protective door 202 is arranged inside the protective chamber 201, a thermal insulation layer 101 is arranged inside the outer cavity 1, an inner cavity 102 is arranged inside the thermal insulation layer 101, a cooling air inlet 3 is arranged above the inner cavity 102, a cooling air duct 301 is arranged at one end of the cooling air inlet 3, a nitrogen inlet 4 is arranged at one end of the outer cavity 1, a circulating air outlet 5 is arranged at the other end of the outer cavity 1, a circulating air inlet 6 is arranged below the outer cavity 1, a plurality of circulating air ducts 601 are arranged on the surface of the circulating air inlet 6, the circulating air duct 601 is communicated with the interior of the inner cavity 102, a fan 602 is arranged inside the circulating air duct 601, and an electric heater 7 is installed inside the inner cavity 102.

[0025] A pig iron casting 10 is arranged inside the inner cavity 102, a placing platform 9 is arranged below the pig iron casting 10, a roller 901 is arranged below the placing platform 9, a track 8 is arranged below the roller 901, a grid 801 is arranged below the track 8, and the track 8 extends from the inside of the inner cavity 102 to the inside of the protective bin 201. The roller 901 can slide on the track 8, thereby driving the placing platform 9 to move, making it convenient for the staff to place the pig iron casting 10 into the inner cavity 102.

[0026] The outer cavity 1, the insulation layer 101 and the inner cavity 102 are all hollow cylindrical structures. Compared with the traditional cube structure with the same length and width, the required heating space during the annealing operation is optimized, and the energy waste is further reduced; a first protective door 2 is arranged on one side of the inner cavity, and the first protective door 2 is connected to the protective chamber 201 by a hinge, and the interior of the second protective door 202 is provided with an insulation layer 101, and the sides of the first protective door 2 and the second protective door 202 are both provided with handles 203, and the second protective door 202 is connected to the track 8 by a slider. When the first protective door 2 and the second protective door 202 are closed, the protective chamber 201 is in a sealed state, and the external pipe of the protective chamber 201 is filled with inert gas to allow the protective chamber 201 to have a heat-insulating function, which helps to reduce the heat diffusion in the inner cavity 102 and further improve the energy utilization rate.

[0027] The nitrogen inlet 4 is connected to the interior of the inner cavity 102, and a nitrogen bin 401 is provided at one end of the nitrogen inlet 4. A heating coil 402 is provided inside the nitrogen bin 401. When the heating coil 402 is energized, the nitrogen in the nitrogen bin 401 is heated, and the heated nitrogen is then filled into the inner cavity 102, thereby avoiding the temperature difference between the nitrogen and the inner cavity 102, thereby affecting the annealing effect; the circulating air outlet 5 is connected to the interior of the inner cavity 102, and one end of the circulating air outlet 5 is connected to the fan 501. The nitrogen inlet 4 injects nitrogen into the inner cavity 102, and the fan 501 draws air from the inner cavity 102 from the circulating air outlet 5. When the nitrogen content in the inner cavity 102 reaches a set value, the circulating air outlet 5 is closed and the fan 602 under the inner cavity is started, forcing the nitrogen to flow in the sealed inner cavity 102, and finally achieving the purpose of uniform nitrogen atmosphere, further avoiding the situation where the annealing effect is not ideal due to uneven atmosphere.

[0028] After the pig iron casting 10 is heated, it needs to be cooled at a certain cooling speed per unit time until the pig iron casting 10 drops to the required temperature and then taken out from the inner cavity to continue cooling. Natural cooling by turning off the electric heater 7 cannot meet the demand. At this time, the cold air is controlled to be filled into the cooling air duct inlet 301 from the cooling air inlet 3, and then evenly filled into the inner cavity 102 from the cooling air duct inlet 301, so as to control the cooling speed of the pig iron casting 10; when the pig iron casting 10 is taken out, a large amount of nitrogen is contained in the inner cavity that needs to be recovered. At this time, the fan 501 is started to extract the nitrogen in the inner cavity 102 from the circulating air outlet 5, and the circulating air duct 601 and the fan 602 are opened to further increase the recovery rate of the nitrogen.

[0029] Working principle: By setting a heat preservation layer 101 inside the outer cavity 1, setting an inner cavity 102 inside the heat preservation layer 101, and setting a protective door and a protective chamber 201 on one side of the inner cavity 102, when the protective door is closed, the protective chamber 201 is in a sealed state, so that the inner cavity 102 is in a sealed state, at this time, nitrogen is injected into the inner cavity 102 through the nitrogen inlet 4, and at the same time, the fan 501 extracts the air in the inner cavity 102 from the circulating air outlet 5. When the nitrogen content in the inner cavity 102 reaches the set value, the circulating air outlet 5 is closed and the fan 602 under the inner cavity 102 is started, forcing the nitrogen to enter the inner cavity 102. The nitrogen gas flows in the cavity 102, and finally a uniform nitrogen atmosphere is achieved; when the pig iron casting 10 is heated, the cold air is controlled to be filled into the cooling air duct inlet 301 from the cooling air inlet 3, and then evenly filled into the inner cavity 102 from the cooling air duct inlet 301, so that the cooling speed of the pig iron casting 10 can be controlled. When the pig iron casting 10 is cooled to the required temperature, a large amount of nitrogen in the inner cavity needs to be recovered. At this time, the fan 501 is started to extract the nitrogen in the inner cavity 102 from the circulating air outlet 5. When the nitrogen concentration in the inner cavity is lower than the set value, the pig iron casting 10 can be taken out to complete the annealing.

[0030] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

Claims

1. An annealing pool for heat treatment of pig iron castings, comprising an outer chamber (1) and an electric heater (7), characterized in that; The invention also comprises a first protective door (2), a protective chamber (201) is arranged on the side of the first protective door (2), a second protective door (202) is arranged inside the protective chamber (201), a heat-insulating layer (101) is arranged inside the outer chamber (1), an inner chamber (102) is arranged inside the heat-insulating layer (101), a cooling air inlet (3) is arranged above the inner chamber (102), a cooling air duct (301) is arranged at one end of the cooling air inlet (3), a nitrogen inlet (4) is arranged at one end of the outer chamber (1), a circulating air outlet (5) is arranged at the other end of the outer chamber (1), a circulating air inlet (6) is arranged below the outer chamber (1), a plurality of circulating air ducts (601) are arranged on the surface of the circulating air inlet (6), the circulating air duct (601) is connected to the inside of the inner chamber (102), a fan (602) is arranged inside the circulating air duct (601), and the electric heater (7) is installed inside the inner chamber (102).

2. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: The outer cavity (1), the thermal insulation layer (101) and the inner cavity (102) are all hollow cylindrical structures.

3. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: The first protective door (2) is connected to the protective chamber (201) via a hinge, a heat-insulating layer (101) is provided inside the second protective door (202), and handles (203) are provided on the sides of the first protective door (2) and the second protective door (202).

4. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: The protection chamber (201) is in a sealed state after being closed, and the protection chamber (201) is externally connected to an inert gas pipeline.

5. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: The nitrogen inlet (4) is in communication with the interior of the inner cavity (102), a nitrogen chamber (401) is disposed at one end of the nitrogen inlet (4), and a heating coil (402) is disposed inside the nitrogen chamber (401).

6. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: The circulating air outlet (5) is in communication with the interior of the inner cavity (102), and one end of the circulating air outlet (5) is connected to the fan (501).

7. The annealing pool for heat treatment of pig iron castings according to claim 1, characterized in that: A pig iron casting (10) is arranged inside the inner cavity (102), a placement platform (9) is arranged below the pig iron casting (10), a roller (901) is arranged below the placement platform (9), a track (8) is arranged below the roller (901), and a grid (801) is arranged below the track (8).

8. The annealing pool for heat treatment of pig iron castings according to claim 7, characterized in that: The track (8) extends from the interior of the inner cavity (102) to the interior of the protective chamber (201), and the second protective door (202) is connected to the track (8) via a slider.

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