Multi-section type steel belt furnace

Abstract

The utility model provides a multi-section type steel belt furnace which comprises a tunnel type furnace body, a steel belt and supporting rollers arranged at the two ends of the steel belt respectively, an upper steel belt carrying materials runs in the tunnel type furnace body and outside the tunnel type furnace body, a lower steel belt not carrying the materials runs below the outside of the tunnel type furnace body, and the supporting rollers are arranged at the two ends of the tunnel type furnace body. A feeding section is arranged in front of the tunnel type furnace body, a cooling section and a discharging section are arranged behind the tunnel type furnace body, and the device is characterized in that the tunnel type furnace body is sequentially provided with a dry hydrogen deoxidation section with a steam exhaust pipe and a hydrogen supply pipe, and a wet hydrogen decarbonization section with an exhaust pipe, a water adding pipe and a nitrogen purging pipe from the feeding end to the discharging end. The problem of mutual influence caused by synchronous deoxidation and decarbonization is fundamentally solved, the raw materials are effectively promoted to complete dry hydrogen deoxidation and wet hydrogen decarbonization processes, the decarbonization rate and deoxidation rate are remarkably increased, the product quality and stability are improved, and large-scale, continuous and low-cost production of fine reduction of iron powder is achieved.

Description

Technical Field

[0001] The utility model relates to a multi-stage steel belt furnace, belonging to the technical field of design and application of main equipment of a steel belt type annealing furnace for powder metallurgy. Background Art

[0002] In terms of the current market, it is required to obtain iron-based powder metallurgy products with good quality and stability at a relatively low price, which can enhance the market competitiveness of products. Using the Panxi vanadium-titanium magnetite resources with rich resources, low price and containing a variety of alloying elements, through catalytic reduction, grinding and separation, drying, and fine reduction in a steel belt furnace, large-scale production of microalloyed iron powder with excellent performance is an important way for enterprises to participate in market competition. However, when the existing microalloyed iron powder raw materials are reduced and sintered in a steel belt furnace, the deoxidation and decarburization will affect each other because they are carried out simultaneously, and the fine reduction atmosphere will be damaged due to the complex gas composition after reduction, ultimately resulting in low decarburization rate and dehydrogenation rate of iron powder and unstable quality. Therefore, it is necessary to innovate the structure on the basis of the existing steel belt type fine reduction furnace for the reduction iron powder raw materials with high carbon content and high hydrogen content, make full use of the principle of "dry hydrogen deoxidation and wet hydrogen decarburization", significantly improve the decarburization rate and dehydrogenation rate, and provide reliable technical support for improving product quality and enhancing product competitiveness. Content of the Utility Model

[0003] In order to eliminate the problems in the production process of microalloyed iron powder, such as the mutual influence between deoxidation and decarburization during the reduction and sintering of raw materials in a traditional steel belt furnace, and the easy destruction of the fine reduction atmosphere due to the complex gas composition after reduction, ultimately resulting in low decarburization rate and dehydrogenation rate of iron powder and unstable product quality, the utility model provides a multi-stage steel belt furnace with a simple structure, in which the two main processes of deoxidation and decarburization are separated or carried out step by step, and the operation is simple.

[0004] The utility model is completed through the following technical solutions: a multi-stage steel belt furnace, including a tunnel furnace body, a steel belt, and support rollers respectively arranged at both ends of the steel belt. Among them, the upper steel belt carrying materials runs in the tunnel furnace body and outside the tunnel furnace body, and the lower steel belt without materials runs below the outside of the tunnel furnace body. An inlet section is arranged in front of the tunnel furnace body, and a cooling section and an outlet section are arranged behind it. Its characteristic is that the tunnel furnace body is sequentially provided with a dry hydrogen deoxidation section with an exhaust pipe and a hydrogen supply pipe, and a wet hydrogen decarburization section with an exhaust pipe, a water supply pipe and a nitrogen purging pipe from the inlet end to the outlet end. So that after the microalloyed iron powder enters the tunnel furnace body with the steel belt through the inlet section, it first independently completes dry hydrogen deoxidation, and then independently completes wet hydrogen decarburization, effectively solving the mutual influence of simultaneous deoxidation and decarburization, and the problem that it is difficult to improve the decarburization rate and dehydrogenation rate due to complex and disordered gas atmosphere after reduction.

[0005] The support rollers at both ends of the steel strip are respectively located outside the feeding section and the discharging section. Among them, the support roller located outside the feeding section is a movable roller for adjusting the tension of the steel strip, and the support roller located outside the discharging section is a driving roller, whose roller shaft is connected to a power machine, so that the driving roller and the movable roller can rotate under the drive of the power machine, and then drive the steel strip to move, enabling the materials on it to complete fine reduction reactions such as deoxidation and decarburization during the movement.

[0006] Above the steel strip in the feeding section, there is a distributor, and behind the distributor, there is an igniter, whose ignition port height is 1.5 m, so that the materials can be distributed on the steel strip through the distributor, and then the coke in the materials can be burned through the igniter, thereby completing fine reduction reactions such as sintering, deoxidation, and decarburization of the materials.

[0007] In the middle and rear part of the dry hydrogen deoxidation section, there is an exhaust pipe with a flared lower end, the height of the exhaust pipe is 1.5 m, and a stop valve is installed on the exhaust pipe. The stop valve is normally closed and is used to discharge the gas in the reaction process in a timely manner to prepare for dry hydrogen deoxidation.

[0008] At the tail of the dry hydrogen deoxidation section, there is a hydrogen supply pipe with a flared lower end. A control valve, a pressure gauge, and a flow meter are installed on the hydrogen supply pipe. The flared lower end of the hydrogen supply pipe is located above the materials on the steel strip, so that after the hydrogen enters the furnace, it can flow under the action of a certain pressure and the suction force of the igniter and the exhaust pipe. While taking away the water vapor generated by the drying and deoxidation reactions, the dry hydrogen deoxidation reaction is completed through the participation of hydrogen in combustion.

[0009] At the tail of the dry hydrogen deoxidation section, a cotton felt is provided for sealing, which is used to prevent the gas and vapor in the section from escaping from the section tail.

[0010] At the head of the wet hydrogen decarburization section, there is an exhaust pipe, which is used to discharge the gas in the reaction process in a timely manner.

[0011] In the front part of the wet hydrogen decarburization section, there is a water addition pipe with a flared lower end. The flared opening is 2 - 3 cm away from the surface of the steel strip. An electric valve, a pressure gauge, and a flow meter are installed on the water addition pipe, so as to add water in a timely manner to complete wet hydrogen decarburization.

[0012] At the tail of the wet hydrogen decarburization section, there is a nitrogen purge pipe with a flared lower end. The flared opening is 2 - 3 cm away from the surface of the steel strip. The nitrogen consumption in the pipe ≤ 80 m 3 / h, so that after the purge nitrogen enters the furnace, it can flow under the action of a certain pressure and the suction force of the exhaust pipe, and then take away the hydrocarbon mixed gas generated by the evaporation of the water added to the furnace by the water addition pipe and the decarburization reaction. At the same time, under the protection of nitrogen, the materials are prevented from being gasified.

[0013] At the tail of the wet hydrogen decarburization section, a cotton felt is provided for sealing, which is used to prevent the gas and vapor in the section from escaping from the section tail.

[0014] The cooling section is respectively set as an air-cooling area at the front and a water-cooling area at the rear. The air-cooling area is in direct contact with air to complete air cooling. The water-cooling area is provided with circulating cooling water pipes, and the steel strip is cooled through the circulating cooling water pipes, thereby cooling the materials on the steel strip.

[0015] Above the steel strip in the discharging section, there is a dust collection hood, and below there is a cleaning and discharging brush. The dust collection hood is connected to a dust collector through a pipeline, which is used to clean the materials after fine reduction, and the dust generated during the cleaning process is collected by the dust collection hood and then sent to the dust collector to complete dust removal, preventing dust from polluting the production workshop.

[0016] Further, the dry hydrogen deoxidation section is composed of two heating zones, with a designed power of 900 KW.

[0017] Further, the wet hydrogen decarburization section is composed of seven heating zones, with a designed power of 850 KW, and the length of each heating zone is 1.7 meters.

[0018] Further, the cooling section is composed of five cooling zones, and the length of each cooling zone is 2.0 meters; among them: there are two air-cooling zones and three water-cooling zones, and the water supply pressure of the water-cooling zone is 0.20 - 0.30 MPa, the diameter of the water pipe is 3 cm, and the cooling water flow rate ≤ 10 m 3 / h, and the cooling water can be recycled.

[0019] Further, three dust collection hoods are provided, and the air extraction power of each dust collection hood is 10 KW.

[0020] The utility model has the following advantages and effects: By adopting the above technical scheme, the two main processes of deoxidation and decarburization of the raw materials in the multi-stage steel strip furnace are separated or carried out step by step, fundamentally solving the mutual influence caused by the simultaneous deoxidation and decarburization, effectively promoting the raw materials to complete the processes of dry hydrogen deoxidation and wet hydrogen decarburization, and eliminating the phenomenon that the carbon and oxygen contents of the raw materials increase due to the disorder of the reduction atmosphere during the reduction process, significantly improving the decarburization rate and deoxidation rate of the fine reduction of iron powder, improving the product quality and stability, realizing the large-scale, continuous and low-cost production of the fine reduction of iron powder, and providing a reliable technical support for obtaining high-quality microalloyed iron powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the utility model;

[0022] Figure 2 is Figure 1 the schematic structural diagram of the dry hydrogen deoxidation section in

[0023] Figure 3 is Figure 1 the schematic structural diagram of the wet hydrogen decarburization section in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The present utility model will be further described below in conjunction with the accompanying drawings. However, it is not limited in any way. Any transformation or improvement based on the teachings of the present utility model falls within the protection scope of the present utility model.

[0025] The multi-stage steel belt furnace provided by the present utility model includes a tunnel furnace body 5, a steel belt 2, and support rollers 1 and 13 respectively arranged at both ends of the steel belt 2. Among them, the upper steel belt carrying materials runs inside and outside the tunnel furnace body 5, and the lower steel belt without materials runs below the outside of the tunnel furnace body 5. An inlet section 18 is provided in front of the tunnel furnace body 5, and a cooling section 15 and an outlet section 19 are provided at the rear. The tunnel furnace body 5 is sequentially arranged from the inlet end to the outlet end: a dry hydrogen deoxidation section 17 with an exhaust pipe 6 and a hydrogen supply pipe 7, and a wet hydrogen decarburization section 16 with an exhaust pipe, a water supply pipe 9, and a nitrogen purging pipe 10;

[0026] The support rollers at both ends of the steel belt 2 are respectively located outside the inlet section 18 and the outlet section 19. Among them, the support roller located outside the inlet section 18 is a movable roller 1 for adjusting the tension of the steel belt 2, and the support roller located outside the outlet section 19 is a driving roller 13, whose roller shaft is connected to a power machine, so that under the drive of the power machine, the driving roller 13 and the movable roller rotate, thereby driving the steel belt 2 to move, enabling the materials on it to complete fine reduction reactions such as deoxidation and decarburization during the movement;

[0027] A distributor 3 is provided above the steel belt 2 in the inlet section 18, and an igniter 4 is provided behind the distributor 3, and the height of its ignition port is 1.5 m;

[0028] The dry hydrogen deoxidation section 17 consists of two heating zones, with a designed power of 900 KW. Among them, in the middle of the second heating zone, an exhaust pipe 6 with a flared lower end is provided, and the height of the exhaust pipe 6 is 1.5 m. A stop valve is provided on the exhaust pipe 6, and the stop valve is normally closed, which is used to timely discharge the gas during the reaction and prepare for dry hydrogen deoxidation;

[0029] At the tail of the second heating zone of the dry hydrogen deoxidation section 17, a hydrogen supply pipe 7 with a flared lower end is provided. A control valve, a pressure gauge, and a flow meter are provided on the hydrogen supply pipe 7. The flared lower end of the hydrogen supply pipe 7 is located above the steel belt materials, so that after hydrogen enters the furnace, it flows under the action of a certain pressure and the suction of the igniter 4 and the exhaust pipe 6, and while taking away the water vapor generated by the drying and deoxidation reactions, the dry hydrogen deoxidation reaction is completed by the participation of hydrogen in combustion;

[0030] A cotton felt 8 is provided at the tail of the dry hydrogen deoxidation section 17 for sealing, which is used to prevent the gas and vapor in the section from escaping from the section tail;

[0031] The wet hydrogen decarburization section 16 consists of seven heating zones with a designed power of 850 KW. The length of each heating zone is 1.7 meters. Among them: an exhaust pipe is provided at the head for timely discharging of the gas during the reaction process; a water adding pipe 9 with a flared mouth at the lower end is provided in the middle, and the flared mouth is 2 - 3 cm away from the surface of the steel strip 2. An electric valve, a pressure gauge, and a flow meter are provided on the water adding pipe 9 for timely water addition to complete wet hydrogen decarburization; a nitrogen purging device 10 with a flared mouth at the lower end is provided at the tail, and the flared mouth is 2 - 3 cm away from the surface of the steel strip. The nitrogen consumption in the pipe is ≤ 80 m 3 / h. After the purging nitrogen enters the furnace, it flows under the action of a certain pressure and the suction force of the exhaust pipe, thereby carrying away the mixed gas of carbon oxides generated after the evaporation of the water added to the furnace by the water adding pipe and the decarburization reaction. At the same time, the material is prevented from being gasified under the protection of nitrogen;

[0032] A cotton felt is arranged at the tail of the wet hydrogen decarburization section 16 for sealing to prevent the gas and vapor in the section from escaping from the tail of the section;

[0033] The cooling section 15 consists of five cooling zones, and the length of each cooling zone is 2.0 meters. Among them: there are two air cooling zones that directly contact with the air to complete air cooling; there are three water cooling zones, and each water cooling zone is provided with a set of circulating cooling water pipes. The water supply pressure of the water cooling zone is 0.20 - 0.30 MPa, the pipe diameter is 3 cm, and the cooling water flow is ≤ 10 m 3 / h. The cooling water can be recycled for cooling the material on the steel strip;

[0034] Above the steel strip 2 of the discharging section 19, a dust hood 12 is provided, and a cleaning brush 14 is provided below. The dust hood 12 is connected to the dust collector through a pipeline. Three dust hoods 12 are provided, and the air extraction power of each dust hood is 10 KW. It is used for cleaning the material after fine reduction, and the dust generated during the cleaning process is collected by the dust hood and sent to the dust collector to complete dust removal, preventing dust from polluting the production workshop.

[0035] By installing an exhaust pipe 6 and a hydrogen supply pipe 7 in the dry hydrogen deoxidation section 17, it is beneficial to timely discharge the water vapor generated after hydrogen reduction and deoxidation, and smoothly complete dry hydrogen deoxidation; by further installing a water adding pipe 9 and a nitrogen purging pipe 10 in the wet hydrogen decarburization section 16, the carbon content in the deoxidized iron powder can be removed to the required carbon content under wet conditions. The installed exhaust pipe is beneficial to timely discharge the carbon oxides generated after decarburization under the action of nitrogen purging, enabling the wet hydrogen decarburization to be smoothly completed during the fine reduction of reduced iron powder in the steel strip furnace, so as to solve the problem of product quality fluctuations caused by furnace atmosphere fluctuations and local uneven reduction. This not only facilitates the precise adjustment of operating parameters, but also further solves the problems in the prior art such as the need to intermittently stop the furnace and remove the volatiles generated by the reaction in the furnace, which affect the output and cost. It realizes stable gas flow distribution, stable reduction and sintering during the fine reduction of iron powder, significantly improves the deoxidation rate and decarburization rate, and obtains a high product qualification rate.

[0036] The utility model has the advantages of simple structure, easy fabrication, low material cost, reliable operation, complete functions, low construction cost, and long service life.

Claims

1. A multi-stage steel strip furnace, comprising a tunnel furnace body, a steel strip, and support rollers respectively arranged at both ends of the steel strip, wherein: The loaded upper steel belt runs in and outside the tunnel type furnace body, and the unloaded lower steel belt runs below the outside of the tunnel type furnace body. A feeding section is provided in front of the tunnel type furnace body, and a cooling section and a discharging section are provided in the rear. The tunnel type furnace body is characterized in that the following are arranged in sequence from the feeding end to the discharging end: a dry hydrogen deoxidation section with an exhaust pipe and a hydrogen supply pipe, and a wet hydrogen decarbonization section with an exhaust pipe, a water supply pipe and a nitrogen purge pipe.

2. The multi-stage steel strip furnace according to claim 1, characterized in that The support rollers at both ends of the steel belt are respectively located outside the feed section and the discharge section. The support roller outside the feed section is a movable roller for adjusting the tension of the steel belt, and the support roller outside the discharge section is an active roller, and its roller shaft is connected to the power machine.

3. The multi-stage steel strip furnace according to claim 1, characterized in that A distributor is arranged above the steel belt of the feeding section, and an igniter is arranged behind the distributor.

4. The multi-stage steel strip furnace according to claim 1, characterized in that An exhaust pipe with a bell-shaped lower end is provided at the middle and rear part of the dry hydrogen deoxidation section, and a stop valve is provided on the exhaust pipe; a hydrogen supply pipe with a bell-shaped lower end is provided at the tail of the dry hydrogen deoxidation section, and a control valve, a pressure gauge and a flow meter are provided on the hydrogen supply pipe, and the bell-shaped lower end of the hydrogen supply pipe is located above the steel strip material; a cotton felt is provided at the tail of the dry hydrogen deoxidation section.

5. The multi-stage steel strip furnace according to claim 1, characterized in that An exhaust pipe is provided at the head of the wet hydrogen decarbonization section; a water supply pipe with a bell-shaped lower end is provided at the front of the wet hydrogen decarbonization section, and an electric valve, a pressure gauge and a flow meter are provided on the water supply pipe; a nitrogen purge pipe with a bell-shaped lower end is provided at the tail of the wet hydrogen decarbonization section; and cotton felt is arranged at the tail of the wet hydrogen decarbonization section.

6. The multi-stage steel belt furnace according to claim 1, characterized in that The cooling sections are respectively configured as a front air cooling zone and a rear water cooling zone. The air cooling zone is directly in contact with air to complete air cooling, and the water cooling zone is provided with a circulating cooling water pipe.

7. The multi-stage steel belt furnace according to claim 1, characterized in that A dust collecting hood is provided above the steel belt of the discharging section and a cleaning brush is provided below the steel belt. The dust collecting hood is connected to the dust collector through a pipeline.

Images