Stainless steel bright annealing horizontal furnace and use method

Abstract

The invention provides a stainless steel bright annealing horizontal furnace and a using method, the stainless steel bright annealing horizontal furnace comprises a furnace body, a preheating muffle and a heating muffle, the preheating muffle and the heating muffle are arranged in the furnace body at intervals along the moving direction of strip steel, carbon sleeve rollers are arranged in the preheating muffle and the heating muffle, furnace shells are arranged outside the preheating muffle and the heating muffle, the preheating muffle is of a double-layer furnace pipe structure, and the heating muffle is of a single-layer furnace pipe structure. A smoke outlet is formed in the side, close to the furnace end, of the double-layer furnace pipe, the double-layer furnace pipe is communicated with a smoke exhaust fan outside the furnace body through a smoke exhaust pipeline, the smoke flowing direction is opposite to the strip steel moving direction, through structural optimization, smoke is fully used for preheating the strip steel, fuel is saved, the production cost is reduced, meanwhile, smoke is discharged smoothly, and the reasonable working furnace pressure of the furnace body is guaranteed.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of a stainless steel bright annealing furnace, in particular to a stainless steel bright annealing horizontal furnace and a use method. BACKGROUND

[0002] With the continuous development of the national economy, the consumption of stainless steel in China will gradually move towards the middle and high end, thus driving the high-quality development of the stainless steel industry. In the future, the proportion of low-end stainless steel products in the stainless steel market in China will continue to decrease, and the proportion of high-quality and high-performance stainless steel will continue to increase. The stainless steel BA (Bright Annealing) plate, that is, the stainless steel bright annealing plate, as a high-tech and high-value product, has better corrosion resistance, decoration, cleanliness and human safety, and is deeply loved by consumers. At present, the product is mainly concentrated in many private enterprises, and the production line has small output, large quantity, low equipment configuration and low automation degree, which is inconsistent with the development route of the national industrial scale, capacity centralization and production line intelligentization.

[0003] Based on the above status, it is urgent to update and replace this type of production line, and a high-yield large-scale stainless steel bright annealing furnace is used to replace the existing low-yield furnace group. The high-yield annealing furnace must first solve the problem of high energy consumption. SUMMARY

[0004] The technical problem to be solved by the application is to provide a stainless steel bright annealing horizontal furnace and a use method to adapt to a production line with large output, high product quality and low energy consumption.

[0005] The embodiment of the application is implemented as follows: The embodiment of the application provides a stainless steel bright annealing horizontal furnace, characterized in that the furnace body is internally provided with preheating muffle and heating muffle which are arranged at intervals along the moving direction of the strip steel, the preheating muffle and the heating muffle are both provided with carbon sleeve rollers, and the outside of each is provided with a furnace shell; the preheating muffle has a double-layer furnace shell structure, the heating muffle has a single-layer furnace shell structure, one side of the double-layer furnace shell close to the furnace head is provided with a smoke exhaust port, the smoke exhaust port is connected with a smoke exhaust fan outside the furnace body through a smoke exhaust pipeline, and the smoke flow direction is opposite to the moving direction of the strip steel.

[0006] In some optional embodiments, the heating muffle is a plurality of muffle, and the heating muffle and the preheating muffle and adjacent heating muffle are all connected and provided with a smoke passage structure.

[0007] In some optional embodiments, the double-layer furnace shell structure of the preheating muffle comprises an inner furnace shell and an outer furnace shell which are sleeved, and forms a smoke flow cavity, and a plurality of guide plates are arranged at intervals in the smoke flow cavity to form a spiral flow channel.

[0008] In some alternative embodiments, the tail end of the preheating muffle extends into the furnace shell of the first heating muffle, the inner furnace shell of the preheating muffle is welded to communicate with the first heating muffle, and the flue gas passage of the first heating muffle is the flue gas flow cavity of the preheating muffle.

[0009] In some alternative embodiments, the connecting part between the bottom plate and the two side plates of the outer furnace shell of the double-layer furnace shell of the preheating muffle is paved with a drag-reducing block, and the working surface of the drag-reducing block is concave arc-shaped structure, which is smoothly connected with the bottom plate and the two side plates.

[0010] In some alternative embodiments, the adjacent heating muffles are connected through connecting flanges, and the flue gas passage structure is a brick-laid passage arranged at the bottom of the furnace shell of the two heating muffles.

[0011] In some alternative embodiments, the adjacent heating muffles are welded to communicate with each other, and the flue gas passage structure is a flue gas pipeline sleeved on the welding part of the two heating muffles, and the two ports of the flue gas pipeline extend into the furnace shells of the two heating muffles, respectively.

[0012] In some alternative embodiments, the distance between the adjacent two baffles decreases along the flue gas flow direction.

[0013] In some alternative embodiments, the bottom surface of the inner furnace shell is uniformly and spacedly welded with fixed fins.

[0014] A use method of a stainless steel bright annealing horizontal furnace, characterized in that the method comprises the following specific contents. The flue gas generated by the burner passes through the single-layer heating muffle in sequence from the tail end of the annealing furnace, enters the flue gas flow cavity of the double-layer preheating muffle, and spirally advances along the baffles, the strip steel enters the annealing furnace from the head end, is preheated and heated in the preheating muffle, and then enters the subsequent heating muffles in sequence, is heated by the combustion of the burner, and is heated by the heated heating muffle through radiation heat transfer, and the flue gas is finally discharged through the exhaust gas pipeline.

[0015] The application has the following beneficial effects: 1. The stainless steel bright annealing horizontal furnace and the use method provided by the application can quickly draw the flue gas generated by the combustion in each heating muffle from the tail end to the exhaust port of the preheating muffle at the head end without increasing the power of the exhaust gas fan, and then the flue gas is discharged to the chimney through the exhaust gas fan, so that the whole annealing furnace works under reasonable furnace pressure; 2. The double-layer preheating muffle adopts a double-layer furnace shell structure, the strip steel entering the furnace is preheated by the flue gas waste heat, the shapes of the inner and outer furnace shells are optimally designed, the flue gas baffles, the heat exchange strengthening fins, and the drag-reducing blocks are arranged, the strip steel can be preheated from room temperature to above 300 DEG C, and a large amount of fuel gas is saved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those of ordinary skill in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0017] Figure 1 A connection diagram of the preheating muffle and the heating muffle of the embodiment of the present application; Figure 2 A bottom view of the heating muffle of the embodiment of the present application; Figure 3 A side view of the heating muffle of the embodiment of the present application; Figure 4 A connection diagram of the preheating muffle and the heating muffle of the embodiment of the present application; Figure 5 A connection diagram of two adjacent sets of heating muffles of the embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art on the basis of the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0020] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0021] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, the terms "first", "second" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0022] The features and performances of the present application are further described in detail below in combination with embodiments.

[0023] As shown in Figure 1 , the present embodiment proposes a stainless steel bright annealing horizontal furnace, which comprises a furnace body 1, a preheating muffle 3 and a heating muffle 4 are arranged in the furnace body along the moving direction of the strip steel 2, carbon sleeve rollers 5 are arranged in the preheating muffle and the heating muffle, and outer furnace shells 6 are arranged outside the preheating muffle and the heating muffle, the preheating muffle has a double-layer furnace shell structure, the heating muffle has a single-layer furnace shell structure, the double-layer furnace shell is provided with a smoke exhaust port on the side close to the furnace head, and the smoke exhaust port is connected in communication with a smoke exhaust fan 8 (see Figure 5 ) outside the furnace body through a smoke exhaust pipeline 7, and the smoke flow direction is opposite to the moving direction of the strip steel.

[0024] The open flame burners installed on the heating section furnace body are distributed above and below the single-layer heating muffle, and the single-layer muffle is heated by the combustion of the burners. The heated muffle heats the continuously running strip steel in the muffle through radiation heat transfer, thereby achieving the purpose of annealing. The smoke exhaust fan sucks the high-temperature smoke in the furnace, and the smoke flows from the furnace tail to the furnace head, enters the preheating muffle, and preheats the strip steel just entering the furnace, which can preheat the strip steel from room temperature to above 300℃, thereby saving a large amount of fuel gas.

[0025] According to the production of the bright annealing line, one or more sets of single-layer heating muffle can be connected with the double-layer preheating muffle. Taking the multiple sets of heating muffle as an example, the heating muffle and the preheating muffle, and the adjacent heating muffle are connected in communication, and are provided with a smoke passage structure.

[0026] Further, the preheating muffle and the heating muffle are both provided with an installation pipe 9 (see Figure 2 ) of the graphite carbon sleeve roller, a water jacket is designed on the installation pipe to reduce the temperature of the sleeve pipe, thereby improving the support strength of the sleeve pipe.

[0027] The preheating muffle and the heating muffle are both provided with a strip passing auxiliary device 10 before and after the installation of the graphite carbon sleeve roller. When the strip is first passed, the auxiliary device can hold up the strip steel wire, and the strip steel can be smoothly passed through each muffle.

[0028] Embodiment 1 As Figure 2 , Figure 3 shown in the present embodiment, the double-layer furnace body structure of the preheating muffle includes an inner furnace body 301 and an outer furnace body 302, which are sleeved inside and outside to form a flue gas flow cavity. A plurality of guide plates 303 are arranged in the flue gas flow cavity to form a spiral flow channel. High-temperature flue gas enters the flue gas flow cavity and flows along the spiral flow channel to the flue gas outlet. The flue gas rotates around the furnace body, increasing the flow distance and improving the heat exchange efficiency.

[0029] Further, the spacing between the two adjacent guide plates decreases along the flue gas flow direction, preferably by 10 mm. The fins 304 are uniformly and spacedly welded on the bottom surface of the inner furnace body to increase the contact area between the flue gas and the inner furnace body, so that more heat is transferred to the inner furnace body, further strengthening the heat exchange and improving the heat exchange effect.

[0030] Further, a drag-reducing block 305 is laid at the connection between the bottom plate and the two side plates of the outer furnace body of the double-layer furnace body of the preheating muffle. The working surface of the drag-reducing block is an inner concave arc structure, which smoothly transitions between the bottom plate and the two side plates. According to the principle of gas dynamics, the along-path resistance of the gas is reduced, and the load of the flue gas fan is reduced.

[0031] Embodiment 2 In the present embodiment, the large-scale stainless steel bright annealing horizontal furnace narrow strip production line has an annual output of ≥60,000 tons, and the annealing furnace is usually configured with one set of double-layer preheating muffle and three sets of single-layer heating muffle.

[0032] The tail end of the preheating muffle extends into the furnace shell of the first heating muffle, and the inner furnace body of the preheating muffle is connected in communication with the first heating muffle by welding. The flue gas passage of the first heating muffle is the flue gas flow cavity of the preheating muffle (see Figure 4 ).

[0033] As Figure 5 shown, the connection structure between the two adjacent sets of heating muffle can be divided into two cases: 1. The two sets of heating muffle are connected through a connecting flange 11, and the flue gas passage structure is a brick-laid passage 12 arranged at the bottom of the furnace shell of the two heating muffle. The high-temperature flue gas flows through the brick-laid passage. The connecting flange is made of the same material as the muffle, and a water jacket, an inlet pipe, and an exhaust valve are arranged on the flange. Only during the heating period of the muffle, water is supplied for cooling, to improve the strength of the flange. After the temperature stabilizes, the exhaust valve is opened, and the inlet pipe is closed, to reduce the heat taken away by the cooling water and improve the heating efficiency of the annealing furnace.

[0034] 2. The two sets of heating muffle can also be connected by welding. The flue gas passage structure is a flue gas pipe 13 sleeved on the welding joint of the two heating muffle. The two ends of the flue gas pipe extend into the furnace shell of the two heating muffle, and the high-temperature flue gas flows through the flue gas pipe.

Claims

1. A horizontal furnace for bright annealing of stainless steel, characterized in that, The furnace includes a furnace body, in which preheating muffles and heating muffles are arranged at intervals along the direction of strip movement. Both the preheating muffles and heating muffles are equipped with carbon rollers inside and a furnace shell on the outside. The preheating muffles have a double-layer furnace shell structure, while the heating muffles have a single-layer furnace shell structure. The double-layer furnace shells have a flue gas outlet on the side near the furnace head, which is connected to the flue gas fan outside the furnace body through a flue gas pipe. The flue gas flow direction is opposite to the direction of strip movement.

2. The horizontal furnace for bright annealing of stainless steel according to claim 1, characterized in that, The heating muffles are multiple, and the heating muffles are connected to each other and to adjacent heating muffles, and are provided with flue gas passage structures.

3. A horizontal furnace for bright annealing stainless steel according to claim 2, characterized in that, The preheating muffle's double-layer furnace structure includes an inner furnace and an outer furnace, forming a flue gas flow cavity. Multiple guide plates are spaced apart within the flue gas flow cavity to form a spiral flow channel.

4. A horizontal furnace for bright annealing of stainless steel according to claim 3, characterized in that, The tail end of the preheating muffle extends into the furnace shell of the first heating muffle, and the inner furnace liner of the preheating muffle is welded and connected to the first heating muffle. The flue gas passage between the first heating muffle and the preheating muffle is the flue gas flow cavity of the preheating muffle.

5. A horizontal furnace for bright annealing stainless steel according to claim 4, characterized in that, The bottom plate and the two side plates of the double-layer furnace liner of the preheating muffle are provided with drag-reducing blocks. The working surface of the drag-reducing blocks has an inwardly concave arc structure and a smooth transition between the bottom plate and the two side plates.

6. A horizontal furnace for bright annealing of stainless steel according to claim 4 or 5, characterized in that, The adjacent heating muffles are connected by connecting flanges, and the flue gas passage structure is a brick-built passage set at the bottom of the furnace shell of the two heating muffles.

7. A horizontal furnace for bright annealing of stainless steel according to claim 4 or 5, characterized in that, The adjacent heating muffles are welded together. The flue gas passage structure is a flue gas pipe that is sleeved on the welded joint of the two heating muffles. The two ends of the flue gas pipe extend into the furnace shell of the two heating muffles respectively.

8. A horizontal furnace for bright annealing of stainless steel according to claim 3 or 5, characterized in that, The spacing between two adjacent guide vanes decreases along the direction of flue gas flow.

9. A horizontal furnace for bright annealing stainless steel according to claim 8, characterized in that, The inner furnace liner has fins welded and fixed at even intervals on its bottom surface.

10. A method of using a horizontal furnace for bright annealing stainless steel as described in claim 5, characterized in that, Includes the following specific content: The flue gas generated by the burner passes sequentially from the tail of the annealing furnace through a single-layer heating muffle and then enters the flue gas flow cavity of a double-layer preheating muffle. The flue gas moves spirally along the guide plate. The strip steel enters the annealing furnace from the furnace head, is preheated by the preheating muffle, and then sequentially enters the subsequent heating muffles. The heating muffles are heated by combustion in the burner. The heated muffles then heat the continuously running strip steel through radiative heat transfer. Finally, the flue gas is discharged through the exhaust pipe.

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