JPS63291615A - Dust collector - Google Patents

Abstract

PURPOSE:To make it possible to blow down a layer of dust deposited efficiently, by providing an air jet nozzle for blowing down dust captured and deposited on a front surface of a filter-material layer wherein granular or block material is filled between supporting members. CONSTITUTION:A filter-material layer 5 in which granular or block material 2 having a diameter of 0.5-10mm are filled between supporting members 3, 4 is provided in the body of a dust collector 1. In front of the filter-material layer 5 a dust blow down nozzle 6 for blowing down dust captured and deposited on the layer 5 is provided. Further, on the back surface of the filter- material layer 5 a back-washing nozzle 7 is provided to cause air for back- washing the filter-material layer to flow therethrough, so that, in the case of back-washing of the filter-material layer, dust captured and deposited is blown down efficiently by jetting air from the nozzles 6, 7.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fixed leaf dust device having a filter layer in which agglomerates are filled between cylindrical or flat supports. It is suitable for dust collection equipment for power generation equipment, fluidized bed boilers, blast furnaces, electric furnaces, glass melting furnaces, nuclear power generation equipment, etc.

[Conventional technology]

Conventionally, as a dry type dust collector for high temperature and high pressure,
Bag filter using m-cloth or non-woven fabric, JP-A-59
BACKGROUND OF THE INVENTION A dust collector having a ceramic filter and a moving bed of a 0-grain agglomerate filter material as shown in Japanese Patent No. 225721 is known.

[Problem that the invention seeks to solve]

However, bag filters using SUS woven fabric or non-woven fabric (■) have drawbacks such as poor corrosion resistance and are expensive materials, and ceramic filters (■) have limited backwashing ability and are difficult to backwash. Disadvantages include the need for high-pressure fluid, the use of very expensive materials, and the possibility of cracking due to thermal shock depending on the material. In addition, the moving bed dust collection device (3) requires a lock hopper or the like to handle moving particles, and has many mechanical drive parts, making the device complicated.

The present invention has been made in view of the above points, and an object of the present invention is to provide a dust collection device that has a simple structure and can obtain high dust collection performance.

c.Means and effects for solving the problems] No. 1 of the present application
The dust collecting device of the invention will be described with reference to the drawings, in which the fixed dust collecting device has a filter layer 5 in which granular material is filled between cylindrical or flat supports 3 and 4. A dust removal nozzle 6 for blowing off the dust collected and accumulated on the front surface of the filter medium layer is installed between the support body and the dust accumulation layer using the 0.5 to 10 dragon particles 2 as the filter medium. It is characterized by being provided so that it is injected.

When dust accumulates in front of the filter layer and the pressure loss of the filter layer increases, high-pressure fluid such as nitrogen, inert gas, or air is injected from the dust removal nozzle 6 to blow off the dust and remove the filter layer. The pressure loss is adjusted.

The particle size of the granular material is 0.5~lOw, preferably 0°8~
If the particle size of the 0-grain agglomerates (3 dragons) is less than 0.5 m, the pressure loss in the filter layer will increase, and the flowering size of the support must be made finer, reducing the porosity of the support. In order to prevent this from decreasing, the manufacturing of the support becomes complicated and the strength of the support becomes low, which is not desirable. Also, if the particle size of the agglomerates exceeds 100, the dust collection efficiency will decrease. , is not preferable when obtaining high dust collection efficiency.

The dust collecting device of the second invention of the present application is a fixed dust collecting device having a filter layer 5 in which agglomerates are filled between cylindrical or flat supports 3.4, the particle size is 0.5 to 10 m. The granular material 2 is used as a filter material, and a dust removal nozzle 6 is installed to blow off the dust collected and deposited on the front surface of the filter material layer so that an air flow is injected between the support and the dust accumulation layer. Further, a backwash nozzle 7 is provided for flowing backwash gas into the filter layer from the gas downstream side of the filter layer to the upstream side.

When dust accumulates on the front surface of the filter layer, high-pressure fluid is jetted from the dust removal nozzle 6 to remove the dust, and backwashing gas is flowed from the backwashing nozzle 7 at the same frequency or less frequently. Backwash the filter media layer.

The dust collecting device of the third invention of the present application is a fixed dust collecting device having a filter layer 5 in which granular material is filled between cylindrical or flat supports 3 and 4, in which an intermediate support is provided between the supports. A body 8 is provided, and the gas inlet side is filled with granular agglomerates 10 having a fine particle size of 0.5 to 1Q mm, and coarse particles 10 of a particle size of 3 to 15 mm are filled in the gas outlet side. A dust blowing nozzle 6 for blowing off the dust collected and accumulated on the front surface of the filter medium layer is provided so that an air flow is injected between the support and the dust accumulation layer. It is characterized by

The particle size of the fine agglomerates filled into the gas inlet side via the intermediate support 8 is 0.5 to 5 mm, preferably 0.8 to 3 mm.
Let it be u. Further, the particle size of the coarse granular agglomerates to be filled on the gas outlet side via the intermediate support is 3 to 1511, preferably 3.
If the particle size of the 9-grain agglomerate is less than 3 mm, the dust collection efficiency is high, but the pressure loss in the filter layer becomes large, so it is necessary to increase the gas pressure of the backwash nozzle. be. In addition, if the particle size of the granular material exceeds 15 tm,
Dust collection efficiency deteriorates, and the filter layer filled with fine particles no longer serves as an aid.

Dust collection is mainly carried out in the fine packing layer, and the coarse packing layer is used to assist the fine packing layer and to increase the strength of the support.

Further, the dust collection device according to the fourth invention of the main rules is a fixed dust collection device having a filter layer 5 in which granular material is filled between cylindrical or flat supports 3 and 4, in which there is an intermediate part between the supports. A support 8 is provided, and through this intermediate support, the gas inlet side is filled with granular agglomerates 10 having a particle size of 0.5 to 10 days, and the gas outlet side is filled with coarse particles 10 having a particle size of 3 to 15 m. A dust removal nozzle 6 for blowing off the dust collected and deposited on the front surface of the filter medium layer is filled with granular material 11 having the same diameter as the filter material layer, and the airflow is injected between the support and the dust pile Ml. Further, a backwash nozzle 7 is provided for flowing backwash gas into the filter layer from the gas downstream side of the filter layer to the upstream side.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, unless there is a specific description, the materials, shapes, relative positions, etc. of the components described in this example are not intended to limit the scope of the present invention to these, but are merely illustrative. Just an example.

FIG. 1 is a schematic diagram of a dust collection device of the present invention.

Reference numeral 1 denotes a device main body, and a filter material layer 5 in which particles 2 having a particle size of 0.5 to 5 particles are filled between supports 3 and 4 is provided in the device main body 1 to constitute a fixed leaf dust device. ing.

As the granular material serving as the filter medium, natural or artificially granulated or processed granular material such as silica sand, ore, metal, metal oxide, granulated slag, and ceramic balls is used. The filter medium particle size is determined in the range of 0.5 to 51 based on parameters such as dust concentration, dust particle size distribution, and collection efficiency.

As the support, a wire mesh, punched metal, porous ceramic, etc. are used, and different supports may be combined on the front and rear surfaces of the filter material packed layer.

A dust removal nozzle 6 is provided on the front surface (gas upstream side) of the filter layer 5 to remove dust collected and deposited on the front surface. Basically, this nozzle 6 is installed parallel to the dust layer surface so that the airflow is injected between the support and the dust accumulation layer at right angles to the gas flow direction, but it is installed at a certain angle with the dust layer. May be attached.

Furthermore, a backwash nozzle 7 is attached so that gas for backwashing the filter medium layer can flow from the rear surface (gas downstream side) of the filter medium M5 in an upstream direction parallel to the gas flow.

Fill the filter with high density to prevent it from lifting up during backwashing and causing a large amount of dust to be re-dispersed downstream. Avoid creating gaps near the bottom and top of the support 3.4, and provide flanged openings at the top and bottom of the filter layer so that the filter can be removed during periodic inspections.

In order to perform backwashing smoothly, a plurality of dust collectors are connected in parallel, or the inside of the dust collector is partitioned into a plurality of parts so that backwashing can be performed sequentially.

Next, the configuration of the filter layer 5, that is, the collection element, will be explained based on FIGS. 2 to 4. Figure 2 shows
Fig. 3 shows a flat collection element filled with agglomerates 2 having a particle size of 0°5 to 5 mm between flat supports 3.4. A cylindrical collection element filled with agglomerated yJ2 having a particle size of 0.5 to 5n is shown. In FIG. 4, a particle size of 0.0 mm is applied to the gas inlet side via an intermediate support 8 such as a wire mesh, punched metal, or porous ceramic.
The figure shows a cylindrical collection element filled with agglomerates 10 having a fine particle size of 5 to 51 fi and coarse agglomerates 11 having a particle size of 3 to 10 m on the gas outlet side. In the collection element shown in Fig. 4, collection is mainly carried out in the fine packing layer, and the coarse packing layer assists the collection of dust in the fine packing layer and strengthens the support (wire mesh with a large wire diameter). , thick punched metal plates can be used).

Note that a flat plate shape may be used instead of a cylindrical shape.

Next, examples of the mechanism for removing accumulated dust are shown in Figures 5 to 7.
This will be explained based on the diagram. FIG. 5 shows a mechanism for removing accumulated dust in a flat collecting element. The dust collection mechanism in the filter layer is as follows. That is, at the initial stage of gas flow, dust adheres to the surface of the filter material and is collected mainly due to inertia and collision effects. The collected dust fills the gaps between the filter media, and the collected dust mainly accumulates near the gas inlet of the filter media layer7! +2 is formed, dust is collected by this dust accumulation layer 12, and the dust accumulation layer grows on the gas upstream side.

When the dust accumulation layer becomes thick to a certain extent, the dust will peel off due to its own weight and fall down in clumps, but the dust removal nozzle 6 is operated so that the dust is peeled off in an accumulative manner and the pressure loss of the filter layer is kept below the set value. Install and periodically inject high-pressure fluid (nitrogen, inert gas, air, etc.). The dust removal nozzle 6 is attached downward from the top of the collection element near the support 3 on the front, but it may also be attached to the side of the support 3, and the nozzle spray direction is parallel to the support. may form a certain angle with the surface of the support.

FIG. 6 shows a dust removal nozzle 6a in a cylindrical collection element in which a gas containing gas is caused to flow from the inside of the cylinder to the outside. Further, FIG. 7 shows a dust removal nozzle 6b in a case where dust-containing gas is caused to flow from the outside to the inside of the cylinder in a cylindrical collection element.

Inside the filter media layer, there is less dust deposited on the front surface of the support on the upstream side, but if the amount gradually increases, it will move against the gas flow from the wake duct as shown in Figure 1. A high-speed airflow is passed in the direction of the filter, and the accumulated dust is caused to fall onto the main part of the filter material by the impact of the ventilation. In this case, as mentioned above, the filter layer and gas passage part are divided into multiple cefsilanes,
It is constructed so that backwashing is carried out sequentially, or it is constructed so that a plurality of dust collectors each having a filter layer are connected in parallel.

FIG. 8 shows a dust collector using a flat collection element. The basic arrangement is one-level difference row arrangement, but if very high dust collection properties are required, the collection elements are installed in two or three levels as shown in FIG. 1
3 is a gas inlet containing gas, 14 is a clean gas outlet, and 15 is a dust outlet.

Further, FIG. 9 shows a dust collection device using a cylindrical collection element. Basically, the dust-containing gas flows from the inside of the cylindrical collection element to the outside, but by making the clean gas outlet 14 the dust-containing gas inlet and the dust-containing gas outlet 13 the clean gas outlet, the cylindrical It is also possible to arrange the gas to flow from the outside to the inside of the collection element. Also, multiple cylinders may be arranged in parallel.

Next, an example of a test conducted by the present inventors using the dust collector of the present invention (having a single filter layer in the form of a flat plate) using dust contained in coal gasification gas will be described.

Test example: 1 g/N+w of dust with a particle size of 2μ+w (50% average)
A high-temperature gas containing 3 was made and passed at a filtration speed of 0.05 m/s through a fixed bed filter material layer in which silica sand with a particle size of 0.9 (50% average) was filled between wire meshes. As a result, the dust concentration in the gas at the outlet of the filter medium layer was approximately 1 mg/Nta3.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

(11 High dust collection efficiency can be obtained with a fixed bed filtration material layer that uses agglomerated particles with a particle size of 0.5 to 5 m as a filtration material.

(2) The dust deposited layer can be efficiently removed by the dust removal nozzle.

(3) Even when a backwash nozzle is installed, dust re-scattering can be suppressed to the same level as a ceramic filter.

(4) There is no need for material handling like in mobile dust removal equipment using granular filter media, making the equipment simple.

(5+ VT The filter material can be easily replaced without disassembling the device itself, so maintenance is easy.

(6) If a natural product such as silica sand is used as a filter material, the material will be extremely cheap.

(7) Since it is a fixed bed, there is no wear of the support by the filter medium compared to the moving bed type.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the dust collection device of the present invention, and FIG.
4 to 4 are perspective views showing examples of collection elements used in the dust collection device of the present invention, and FIGS. 5 to 7 are perspective illustrations showing examples of the accumulated dust removal mechanism in the dust collection device of the present invention. 8 and 9 are partially cutaway perspective views showing an example of an assembled state of the dust collector of the present invention.

Claims (1)

[Scope of Claims] 1. In a fixed bed dust collector having a filter layer in which particulate matter is packed between cylindrical or flat supports, the particle size is 0.
．． A granular material with a size of 5 to 10 mm is used as a filter medium, and a dust removal nozzle is installed to blow off the dust collected and accumulated on the front surface of the filter medium layer, so that an air flow is injected between the support and the dust accumulation layer. A dust collection device characterized by being installed in. 2 In a fixed bed dust collector having a filter layer in which granular material is packed between cylindrical or flat supports, the particle size is 0.
．． A granular material with a size of 5 to 10 mm is used as a filter medium, and a dust removal nozzle is installed to blow off the dust collected and accumulated on the front surface of the filter medium layer, so that an air flow is injected between the support and the dust accumulation layer. 1. A dust collector, further comprising a backwash nozzle for flowing backwash gas into the filter layer from the gas downstream side of the filter layer to the upstream side. 3. In a fixed bed dust collector having a filter layer in which particulate matter is filled between cylindrical or flat supports, an intermediate support is provided between the supports, and the gas inlet side is provided through the intermediate support. is filled with fine agglomerates with a particle size of 0.5 to 10 mm, and the gas outlet side is filled with coarse agglomerates with a particle size of 3 to 15 mm, which are collected and deposited on the front of the filter layer 1. A dust collection device, comprising: a dust removal nozzle for blowing off accumulated dust such that an airflow is injected between a support and a dust accumulation layer. 4. In a fixed bed dust collection device having a filter layer in which agglomerates are filled between cylindrical or flat supports, an intermediate support is provided between the supports, and a gas inlet side is provided through the intermediate support. is filled with fine agglomerates with a particle size of 0.5 to 10 mm, and the gas outlet side is filled with coarse agglomerates with a particle size of 3 to 15 mm, which are collected and deposited on the front of the filter layer A dust removal nozzle for blowing off the dust accumulated is provided so that an air flow is injected between the support and the dust accumulation layer, and a dust removal nozzle is installed in the filter layer from the gas downstream side of the filter layer to the upstream direction. A dust collector characterized by being provided with a backwash nozzle for flowing backwash gas.