CN112981030B

CN112981030B - Reduction shaft furnace

Info

Publication number: CN112981030B
Application number: CN202110201193.7A
Authority: CN
Inventors: 李菊艳
Original assignee: Wisdri Engineering and Research Incorporation Ltd
Current assignee: Wisdri Engineering and Research Incorporation Ltd
Priority date: 2021-02-23
Filing date: 2021-02-23
Publication date: 2022-10-14
Anticipated expiration: 2041-02-23
Also published as: CN112981030A

Abstract

The invention relates to a reduction shaft furnace, which comprises a furnace body, wherein the top of the furnace body is provided with a feeding device, the bottom of the furnace body is provided with a discharging device, the furnace body comprises a reduction section, a buffer section and a cooling section which are sequentially arranged from top to bottom, the reduction section is internally divided into a plurality of heating chambers and a plurality of reduction chambers by heat-conducting partition walls, and the cooling section is internally divided into a plurality of cooling chambers by cooling partition walls; the buffer section is a hollow section, each reduction chamber and each cooling chamber are communicated with the buffer section, and a coal gas outlet is formed in the buffer section. The furnace body is designed to comprise a reduction section, a buffer section and a cooling section which are sequentially arranged from top to bottom, wherein the flow area of furnace burden limited by the buffer section is larger than that in the reduction section, and coal gas generated in a reduction chamber easily flows into the buffer section in a relatively low-pressure environment, so that the coal gas is conveniently led out from a coal gas outlet on the buffer section. The invention avoids the condition that each reduction chamber needs to be provided with a gas outlet pipe, and the furnace body has simple structure and is easy to produce, manage and maintain.

Description

Reduction shaft furnace

Technical Field

The invention belongs to the technical field of metallurgical equipment, and particularly relates to a reduction shaft furnace which can be used for treating wastes containing valuable metals.

Background

A large amount of dust and sludge can be generated in the steel production, and the generation amount is about 10 percent of the steel yield generally; these dusts/sludges contain a large amount of Zn element in addition to Fe, and some dusts have a very fine particle size, and are called difficult-to-utilize dusts/sludges or zinc-containing dusts/sludges.

The reduction process for producing reduced iron using these dusts/sludges is extensive, and among them, the reduction method for reducing these dusts/sludges in reduction furnaces such as a shaft reduction furnace, a rotary hearth furnace, and a rotary kiln reduction furnace is widely used.

Patent CN109385534A discloses a method for treating dust containing zinc and alkali metal halide, which comprises feeding a reducing agent and dust containing iron oxide, zinc and alkali metal halide into a vertical reduction chamber, heating the vertical reduction chamber by a flame-proof heating method, and allowing the dust containing iron oxide, zinc and alkali metal halide to undergo a reduction reaction under the condition of isolating air; and the exhaust gas of the vertical reduction chamber enters a lead-rain condenser to recover crude zinc. The method realizes the purpose of separating zinc, iron oxide and alkali metal halide, and avoids the phenomenon that zinc oxide, halogen, alkali metal and the like are condensed together into secondary dust. However, in this method, the gas generated in each reduction chamber needs to be led out at high temperature, so that each reduction chamber needs to be provided with a gas leading-out pipe, and the reduction furnace has the problems of complicated structure, bad working environment of the leading-out pipe, difficult maintenance, increased equipment cost and the like.

Patent CN107904347A discloses a coal-based direct reduction shaft furnace and a reduction method, which comprises a furnace body, a preheating section is arranged above the outside of the furnace body, a material distribution mechanism, a combustion chamber and a cooling section are sequentially arranged in the furnace body from top to bottom, the reduction section is arranged in the combustion chamber in a penetrating manner, the preheating section is coaxially arranged with the reduction section through the material distribution mechanism, a discharge hole of the material distribution mechanism is communicated with a feed hole of the reduction section, a discharge hole of the reduction section is communicated with a feed hole of the cooling section, a heat source introducing port is arranged at the lower part of the preheating section, a high-temperature waste gas outlet is arranged at the upper part of the combustion chamber, and the high-temperature waste gas outlet is connected with the heat source introducing port of the preheating section through a waste gas discharge pipeline. However, the reduction furnace and the reduction method need to arrange the material distribution mechanism between the upper part and the lower part of each reduction chamber, so that the material distribution mechanisms are more, and the material distribution mechanisms operate at high temperature, and the problems of high equipment requirement, investment increase, difficult maintenance and the like exist.

Disclosure of Invention

The present invention relates to a reduction shaft furnace which solves at least some of the drawbacks of the prior art.

The invention relates to a reduction shaft furnace, which comprises a furnace body, wherein the top of the furnace body is provided with a feeding device, the bottom of the furnace body is provided with a discharging device, the furnace body comprises a reduction section, a buffer section and a cooling section which are sequentially arranged from top to bottom, the reduction section is internally divided into a plurality of heating chambers and a plurality of reduction chambers by a heat-conducting partition wall, and the cooling section is internally divided into a plurality of cooling chambers by a cooling partition wall; the buffer section is a hollow section, each reduction chamber and each cooling chamber are communicated with the buffer section, and a coal gas outlet is formed in the buffer section.

In one embodiment, the heating chambers are arranged in line with the reduction chambers, and each adjacent two heating chambers are surrounded by one reduction chamber.

As one embodiment, the number of the reduction chambers is the same as that of the cooling chambers, and the cooling chambers are arranged in a one-to-one correspondence mode, and each cooling chamber is positioned right below the corresponding reduction chamber.

As an embodiment, the cooling chamber and the reduction chamber are both square chambers and have the same length and the same width.

In one embodiment, the cooling partition is a water-cooled partition.

As one embodiment, the furnace body further comprises a hollow charging section located above the reduction section, and the charging device is arranged at the top of the hollow charging section.

In one embodiment, the top of each of the reduction chambers is in the shape of a bell mouth with a wide top and a narrow bottom.

In one embodiment, the top of each cooling chamber is in a bell mouth shape with a wide top and a narrow bottom.

In one embodiment, the heating chamber has a heat exchange flue gas inlet and a heat exchange flue gas outlet.

In one embodiment, the furnace shell of the furnace body is a steel shell lined with a refractory material layer.

The invention has at least the following beneficial effects:

the reduction shaft furnace provided by the invention has the advantages that the furnace body is designed to comprise the reduction section, the buffer section and the cooling section which are sequentially arranged from top to bottom, the flow area of furnace burden limited by the buffer section is larger than that of the furnace burden in the reduction section and larger than that of the furnace burden in the cooling section, and on the premise of ensuring the downward smoothness of the furnace burden, coal gas generated in the reduction chamber can easily flow into the buffer section in a relatively low-pressure environment, so that the coal gas can be conveniently led out from a coal gas outlet on the buffer section. The invention avoids the condition that each reduction chamber needs to be provided with a coal gas eduction tube, and the furnace body has simple structure and is easy to produce, manage and maintain.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural view of a reduction shaft furnace according to an embodiment of the present invention;

fig. 2 isbase:Sub>A sectional view taken along linebase:Sub>A-base:Sub>A of fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the embodiment of the present invention provides a reduction shaft furnace, which comprises a furnace body, wherein a feeding device 11 is arranged at the top of the furnace body, a discharging device 51 is arranged at the bottom of the furnace body, the furnace body comprises a reduction section 2, a buffer section 3 and a cooling section 4 which are sequentially arranged from top to bottom, the reduction section 2 is divided into a plurality of heating chambers 21 and a plurality of reduction chambers 22 by a heat conducting partition wall 23, and the cooling section 4 is divided into a plurality of cooling chambers 42 by a cooling partition wall 41; the buffer section 3 is a hollow section, each reduction chamber 22 and each cooling chamber 42 are communicated with the buffer section 3, and a coal gas outlet 31 is formed in the buffer section 3.

The reduction shaft furnace described above is preferably used for the production of direct reduced iron, for example for the treatment of metallurgical charge materials such as zinc-containing dust/zinc-containing dust sludge.

The charging device 11 is used for charging reaction furnace materials into each reduction chamber 22; in one embodiment, as shown in fig. 1, the furnace body further comprises a hollow feeding section 1 positioned above the reduction section 2, and the feeding device 11 is arranged at the top of the hollow feeding section 1. Distributing materials into the hollow feeding section 1 through the feeding device 11, wherein furnace materials in the hollow feeding section 1 can uniformly enter each reduction chamber 22; the number of the feeding devices 11 can be determined according to the cross-sectional area of the hollow feeding section 1, the reaction efficiency in the reduction section 2 and other factors, and is preferably distributed by a plurality of feeding devices 11, as shown in fig. 1 and 2.

Obviously, it is necessary to avoid the charge material from entering into the heating chamber 21, therefore, the heating chamber 21 is isolated from the hollow charging section 1, the top of the heating chamber 21 is a closed end, and the heating chamber 21 and the reduction chamber 22 are in a separate state, and the heat in the heating chamber 21 is transferred to the charge material in the reduction chamber 22 through the heat conducting partition wall 23. Correspondingly, the heating chamber 21 is preferably a closed chamber formed by enclosing the two heat-conducting partition walls 23 and the furnace shell, a burner or a heat exchange medium pipe 211 can be arranged at the corresponding position of the furnace shell, and the heat exchange medium can be high-temperature gas or the like; in this embodiment, the heating chamber 21 has a heat exchange flue gas inlet and a heat exchange flue gas outlet, and the heat exchange flue gas is introduced into the heating chamber 21 as a heat source, and the heat exchange flue gas may be a byproduct high-temperature flue gas in the metallurgical industry, or a byproduct gas in the metallurgical industry may be combusted to generate the high-temperature flue gas.

Preferably, the furnace shell of the furnace body is a steel structure shell lined with a refractory material layer, the steel structure shell can ensure the structural strength and the operational reliability of the furnace body, the furnace shell has a long service life, and the refractory material layer can ensure the sealing performance of the furnace shell and has a heat preservation effect. The furnace shell can be a cuboid furnace shell or a cylindrical furnace shell; referring to fig. 1 and 2, in the present embodiment, a rectangular parallelepiped furnace casing is used.

In one embodiment, as shown in fig. 1, the heating chambers 21 are arranged in a line with the reduction chambers 22, wherein one reduction chamber 22 is enclosed between every two adjacent heating chambers 21. This solution is particularly suitable for structures using a cuboid furnace shell. Each heating chamber 21 can supply heat to two adjacent reducing chambers 22 respectively, namely, two heating chambers 21 of each reducing chamber 22 supply heat to the heating chambers, so that the temperature required by the reduction reaction, the heating efficiency of the furnace materials and the heating uniformity can be ensured.

Further preferably, as shown in fig. 1, the reducing chambers 22 and the cooling chambers 42 are arranged in the same number and in one-to-one correspondence, and each cooling chamber 42 is located right below the corresponding reducing chamber 22. The reduction chamber 22 defines an upper furnace charge channel running from top to bottom, the cooling chamber 42 also defines a lower furnace charge channel running from top to bottom, and the reduction chamber 22 is opposite to the cooling chamber 42 from top to bottom, so that furnace charges in the upper furnace charge channel can conveniently fall into the lower furnace charge channel, and the smoothness of descending of the furnace charges in the furnace body is ensured.

In the above-mentioned solution using a rectangular parallelepiped furnace shell and arranging each heating chamber 21 and each reducing chamber 22 in a straight line, it is known that the reducing chamber 22 is a square chamber, and then the cooling chamber 42 is also preferably a square chamber, and further preferably the cooling chamber 42 and the reducing chamber 22 have the same length and the same width, so that the furnace burden in each reducing chamber 22 can descend to each cooling chamber 42 below one to one, thereby reducing or avoiding the stagnation of the furnace burden in the buffer section 3, and simultaneously facilitating the structural design of the reduction shaft furnace. Accordingly, the width of the cooling partition 41 may be designed to be the same as the width of the heating chamber 21 (including the width of the corresponding both-side heat conductive partition 23).

The cooling section 4 is used for cooling the reduced charge, and in one embodiment, the charge is cooled to about 100 ℃. In the present embodiment, the cooling partition wall 41 is a water-cooled partition wall, for example, the cooling partition wall 41 is designed as a hollow partition wall, and cooling water flows through a cavity therein; the superheated/saturated steam generated in the cooling partition 41 can be utilized, for example, for steam power generation or for other steam users in the metallurgical industry.

Preferably, as shown in fig. 1, the top of each reduction chamber 22 is in a bell mouth shape with a wide top and a narrow bottom, so that the burden in the hollow feeding section 1 can enter the reduction chamber 22, and the downward smoothness of the burden in the furnace body can be improved.

Preferably, as shown in fig. 1, the top of each cooling chamber 42 is in a bell mouth shape with a wide top and a narrow bottom, so that the charging in the buffer section 3 can enter the cooling chamber 42, and the smoothness of the downward movement of the charging in the furnace body can also be improved.

The heat-conducting partition 23 and the cooling partition 41 may be made of highly heat-conducting refractory bricks, etc., which are conventional in the art and will not be described in detail herein.

The discharging device 51 is used for discharging the cooled furnace burden to the outside of the furnace body; in one embodiment, as shown in fig. 1, the furnace body further comprises a hollow discharge section 5 below the cooling section 4, and the discharge device 51 is arranged at the bottom of the hollow discharge section 5. The furnace burden in each cooling chamber 42 enters the hollow discharging section 5 and is discharged by the discharging device 51; preferably, the hollow discharging section 5 is designed to be a bucket body with a wide upper part and a narrow lower part, so that the furnace burden can be conveniently emptied; the number of the discharging devices 51 can be determined according to the cross-sectional area of the hollow discharging section 5, the reaction efficiency in the reduction section 2 and other factors, and as shown in fig. 2, it is preferable to discharge by using a plurality of discharging devices 51.

It can be understood that the heat-conducting partition wall 23 extends from top to bottom to terminate at the top end of the buffering section 3, the cooling partition wall 41 extends downwards from the bottom end of the buffering section 3, and no other partition wall or other structural members are preferably arranged in the buffering section 3, i.e. the buffering section 3 defines a charge flow area which is the same as the inner ring cross-sectional area of the buffering section 3, and the buffering section 3 defines a charge flow area which is larger than the charge flow area in the reduction section 2 and larger than the charge flow area in the cooling section 4. Based on the design, the coal gas generated in the reduction chamber 22 can easily flow into the buffer section 3 in a relatively low-pressure environment, and the coal gas outlet 31 is arranged on the buffer section 3, so that the coal gas is conveniently led out. In addition, the buffer section 3 is positioned at the tail end of the reduction section 2, the furnace burden is not cooled, and the temperature of the coal gas is higher, so that the coal gas can be led out in a high-temperature coal gas mode, and the condensation and deposition of zinc vapor contained in the coal gas in a coal gas leading-out pipe can be avoided when materials containing zinc dust/zinc dust mud and the like are treated.

Furthermore, preferably, the top and the bottom of the buffer section 3 are respectively provided with a bearing structural member to ensure the structural strength and the rigidity of the furnace body; to the furnace body that adopts steel construction shell, this bearing structure spare also is the steel member.

It is further preferable that, as shown in fig. 1, a baffle plate 32 is provided at the gas outlet 31 to prevent the burden from blocking the gas outlet 31, and at the same time, since the baffle plate 32 can prevent the gas from horizontally passing through the gas outlet 31, the flow direction of the gas can be changed, thereby playing a certain role in gas dust removal. In one embodiment, the striker plate 32 is an L-shaped plate, and encloses with the furnace shell to form a slot cavity with an open bottom, the top plate surface of the striker plate 32 can be parallel to the horizontal plane, or the top plate can be designed to be arranged obliquely and the top end thereof is installed on the furnace shell.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a reduction shaft furnace, includes the furnace body, and the furnace body top is equipped with feeding device, and the furnace body bottom is equipped with discharge device, its characterized in that: the furnace body comprises a reduction section, a buffer section and a cooling section which are sequentially arranged from top to bottom, the reduction section is internally divided into a plurality of heating chambers and a plurality of reduction chambers by heat conduction partition walls, and the cooling section is internally divided into a plurality of cooling chambers by cooling partition walls; the buffer section is a hollow section, each reduction chamber and each cooling chamber are communicated with the buffer section, a coal gas outlet is formed in the buffer section, and the flow area of the furnace burden limited by the buffer section is larger than the flow area of the furnace burden in the reduction section and the flow area of the furnace burden in the cooling section.

2. The reduction shaft furnace of claim 1, wherein: the heating chambers and the reduction chambers are arranged in a straight line, wherein one reduction chamber is formed by enclosing between every two adjacent heating chambers.

3. The reduction shaft furnace of claim 1, wherein: the number of the reduction chambers is the same as that of the cooling chambers, and the reduction chambers and the cooling chambers are arranged in a one-to-one correspondence mode, and each cooling chamber is located right below the corresponding reduction chamber.

4. The reduction shaft furnace of claim 3, wherein: the cooling chamber and the reduction chamber are both square chambers and have the same length and the same width.

5. The reduction shaft furnace of claim 1, wherein: the cooling partition wall is a water-cooling partition wall.

6. The reduction shaft furnace of claim 1, wherein: the furnace body still including being located reduction section top's cavity adds the material section, feeding device locates the top of cavity adds the material section.

7. The reduction shaft furnace of claim 6, wherein: the top of each reduction chamber is in a bell mouth shape with a wide top and a narrow bottom.

8. The reduction shaft furnace of claim 1, wherein: the top of each cooling chamber is in a bell mouth shape with a wide top and a narrow bottom.

9. The reduction shaft furnace of claim 1, wherein: the heating chamber is provided with a heat exchange flue gas inlet and a heat exchange flue gas outlet.

10. The reduction shaft furnace of claim 1, wherein: the furnace shell of the furnace body is a steel structure shell lined with a refractory material layer.