JP3334932B2 - Dust collection device and dust collection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collector for filtering dust contained in a gas such as a gas discharged from various plants.
The present invention relates to an apparatus and a dust collection method , and more particularly to a gas processing technique for reducing damage to specific members of an apparatus due to a high-temperature gas.

[0002]

2. Description of the Related Art As is well known, steel, electric power, ceramics, metallurgy,
High-temperature gas generated in the chemical field contains dust. As means for removing this, see, for example,
A dust collector as disclosed in Japanese Patent No. 31811 has been proposed. Here, there is a conventional dust collector, for example, one using a filter element for filtering particulate dust from exhaust gas such as flue gas in a factory. Depending on the gas or the substance to be filtered, the filter element may be a fiber filter, carbon fiber filter, felt filter,
Paper filters, plastic filters, metal filters and the like are used.

[0003] Each of the above filters is used properly in terms of heat resistance and corrosion resistance. For example, the working temperature of the fiber filter, felt filter, paper filter, and plastic filter is about 150 ° C or less, and the working temperature of the glass fiber filter is about 150 ° C or less. The temperature is up to about 250 ° C., and the operating temperature of the metal fiber filter is up to about 500 ° C. Metal fiber filters cannot withstand gases containing hydrochloric acid or sulfuric acid. For this reason, when collecting high-temperature gas, the temperature of the gas is lowered with dilution air, and the filter is used or wet processing is applied. The ceramic filter can be used at a gas temperature of about 1000 ° C., and has an advantage that the purified gas after dust removal can be reused as a heat source. Further, since it is a dry type, there is no need for water treatment or sludge treatment.

[0004] In particular, in a device using a filter capable of filtering a high-temperature gas such as a ceramic filter, when the high-temperature gas is rapidly aspirated or when the gas temperature rises or falls rapidly, the filter element or the filter is used. The member to which the element is fixed and the container (can) containing the element may be damaged. Therefore, as disclosed in JP-A-63-62520,
A dust collector provided with a cooling pipe for flowing a cooling fluid through a container body has been proposed. In general, in a dust collector that treats a high-temperature gas, one of the major factors of its ability is to have an ability to cope with a rapid change in gas temperature. In other words, the fact that this dust collector is a facility capable of collecting gas having a rapid temperature change without any problem means that the dust collector does not limit the operation mode of the factory, and its applicable range Will be wide.

[0005]

By the way, in the dust collector, a top plate is fixed to the inside of the container, in other words, a top plate is fixed to the flow path of the gaseous body. Some have a fixed structure. This dust collector basically has a structure in which the top plate is used as a holding and fixing means of the filter element, and the filter element can be relatively easily removed from the top plate, or by blowing air or the like into the filter element. Since it is excellent in terms of maintenance, such as being able to be cleaned while the filter element is mounted, there are many expectations among many types of dust collectors. However, if there is a sudden suction of a high-temperature gas or a sudden rise or fall in the gas temperature during operation, a difference occurs in the temperature distribution in the top plate, causing internal distortion, cracking and leakage of the top plate, and furthermore, the top plate. There has been a problem that the filter element is also damaged with the breakage of the filter element. For this reason, an object of the present invention regardless of the temperature of the hot gas, the dust collector and the dust collection side can avoid damage to the top plate fixed holding the filter element
Is to provide a law .

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to collect dust.
So as to define the interior of the container body for primary and secondary sides.
The filter element is fixed by the top plate fixed to the inner wall of the container.
It is held and fixed, and the gas supplied from the primary side is
Contained in the gas by passing through the filter element
In the dust collector in which the dust is filtered,
On the gas discharge side of the filter element, the gas on the secondary side is
A flow is formed to temporarily form a flow along the top plate.
Flow means is provided, and the temperature of the top plate is controlled by the temperature of the gas.
Dust collector characterized by averaging the degree over the entire area
Is achieved by placing Further, the rectifying means is provided with the filter.
Is provided so as to substantially face the gas exhaust hole of the filter element.
Plate or the gas on the secondary side is the outer periphery of the top plate
To the outer peripheral side of the top plate to flow toward
Can be configured as multiple gas outlets
Things.

[0007] The object of the present invention is to provide a dust collection device according to claim 1.
The dust collection method is characterized by collecting dust using a device.
Achieved.

[0008]

SUMMARY OF] According to the dust collector and the dust collection method, the secondary side of the gas filtered by the filter element in the vicinity of the top plate, (the outer peripheral side of the top plate) flow rate of the gas is small region
The temperature difference between the central region and the outer peripheral region of the top plate can be reduced. Thereby, deformation and breakage can be avoided by suppressing internal distortion of the top plate .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dust collecting method according to the present invention and a dust collecting apparatus to which the method is applied will be described below with reference to FIGS.
FIG. 1 is a schematic internal side view of a main part of a dust collector according to the present invention, FIG. 2 is a schematic cross-sectional view of a portion along line AA in FIG. 1, and FIG. 3 is a filter element. FIG. 4 is a schematic internal side view of a main part of a dust collector according to another embodiment of the present invention, and FIGS. 5 and 6 are temperature characteristics showing changes in temperature distribution. FIG. First, a configuration of a main part of the dust collecting apparatus 1 will be described. The container body 2 is defined by a top plate 11 in a primary region 3A for storing a high-temperature gas before filtering and a secondary region 3B through which the filtered gas passes. This top plate 11 is fixed to the inner wall of the container 2. A blow port 4 for blowing high-temperature gas is formed in a lower slope portion of the container body 2, and a discharge port 5 for discharging clean gas after dust collection is formed at an upper end.
Are formed. Further, the lower part of the container body 2 is formed in a funnel shape, and a dust discharge port 6 for discharging collected dust and the like is provided at the lowermost end so as to be able to be closed. In this embodiment, the high-temperature gas is a general term for gases having a temperature of several tens of degrees C or more regardless of the type of gas.

A number of filter elements 12 are appropriately fixed between the top plate 11 and the lower supporting portion 40 via a spring 33 or the like, and the high-temperature gas G supplied to the primary side from the lower blowing port 4 is provided. And the filtered gas flows from the discharge hole 17 of each filter element to the secondary side. In addition,
The support portion 40 is appropriately configured in a lattice shape or the like so as not to obstruct the flow of the gas G supplied from below as much as possible. An injection nozzle 13 is disposed above the filter element 12 so as to face the discharge hole 17.
Are provided. The operation of the current plate 14 will be described later in detail together with the description of the dust collection method.

Next, the container body 2 will be described with reference to a section taken along the line AA. In this embodiment, the container body 2 is formed in a rectangular shape as shown in FIG. And the lower side (primary side) of the top plate 11
Are provided with a plurality of filter elements 12 at desired intervals (intervals P1 and P2).
A configuration in which, for example, an injection nozzle 13 having a structure in which holes are formed at predetermined intervals in, for example, a pipe-shaped pipe is disposed above the discharge hole 17, and a rectangular straightening plate 14 as illustrated is disposed between the injection nozzles 13. It is. Further, a predetermined gap L is formed between the container body 2 and the current plate 11, and the gas discharged from the discharge hole 17 flows through the gap L to the upper discharge port 5. The spray nozzle 13 blows out air or a suitable gas from the discharge nozzles 17 into the discharge holes 17 to blow off dust attached to the outside of the filter element 12 to clean the filter element. Although not shown in each figure, the injection nozzle 13 is provided with a pipe for supplying gas.

The filter element 1 applied to this embodiment
Numeral 2 is, for example, a cylindrical shape as shown in FIG. 3, and is sandwiched between a discharge pipe 21 fixed to the top plate 11 and a lower holding portion 30. The discharge pipe 21 fixed to the top plate 11 has, for example, seal members 2 above and below a flange 22.
3 and 24. The holding portion 30 provided on the support portion 40 has a flange 31, a seal member 32 is provided on the upper surface side of the flange 31, and a compression spring 33 is provided on the lower side. With such a configuration, a large number of filter elements 12 can be easily attached and detached, and the maintenance property is good. Further, as the filter element 12, a ceramic filter having excellent heat resistance is suitable, but a filter using metal fibers can also be used. Since the high-temperature gas G has a high temperature of, for example, 500 ° C. as shown in the temperature characteristic diagram, the container body 2 and the top plate 1
1. The material of the current plate 14 is made of a material having excellent heat resistance. Further, a door that can be opened and closed for maintenance is provided on the side of the container body 2.

Next, a dust collection method will be described. In the following description, the high-temperature gas before dust collection is G, and the high-temperature gas after dust collection is g. The high-temperature gas G is supplied from the blowing port 4 to the container 2.
Inside, that is, into the gas passage 3. At this time, it may be sent while pressurizing at a predetermined pressure. The hot gas G is shown in FIG.
As shown in (1), the filter member 23 passes through the entire surface of the outer peripheral surface of the filter 12, and at this time, for example, particulate dust contained in the high-temperature gas G is filtered. Therefore, the hot gas g is filtered and clean.
Are discharged to the upper part of the top plate 11 from the discharge holes 17 of the upper surface.

The high-temperature gas g is discharged from the discharge holes 17 to the upper portion of the top plate 11 and then diffuses laterally along the top plate 11 against the rectifying plate 14. Accordingly, the high-temperature gas g discharged from each filter element 12 flows in the outer circumferential direction of the current plate 14 and then flows upward. As a result, the high-temperature gas g also flows toward the outer peripheral edge of the top plate 11, so that the outer peripheral portion of the top plate 11 is also heated by the high-temperature gas g similarly to the central portion. That is, the outer peripheral edge of the top plate 11 located near the side wall of the container body 2 in which the gas flow is relatively stagnant and is easily affected by the temperature of the outside air has a high temperature gas g.
And the temperature of the entire top plate is averaged over the entire area.

Next, the dust collecting apparatus shown in FIGS. 1 to 3 was operated to perform a dust collecting process. The temperature distribution of the top plate 11 at this time will be described with reference to FIGS. The Y axis of the temperature characteristic shown in FIG. 5 indicates the temperature, the X axis indicates the distance from the center of the top plate 11 to the inner side surface of the container 2, and the center line O indicates the center of the top plate 11. In the example, it corresponds to the center of the current plate 14. The size of the container 2 is 17
50mm square, the material is SS400 and the inner surface is 10mm
A heat insulating material of about 0 mm is provided. The top plate 11 is made of SUS304 and has a thickness of 25 mm. On the top plate,
400 filter elements are arranged at equal intervals. The distance L0 between the outermost filter element and the side wall of the container 2 is 305 mm, and the value 875 mm described at both ends of the X axis is the distance from the center of the top plate 11 to the inner surface of the container 2. Further, the distance L between the current plate 14 and the inner surface of the container body 2 is 255 mm, and the current plate 14 and the top plate 11
Was set to 100 mm. Processing air volume is 64m ³ /
min. The rate of temperature rise is 300 ° C./h.
Under the conditions described above, dust collection processing was performed when the high-temperature gas G was 500 ° C. As a result, as shown by the temperature distribution characteristic ta in FIG. 5, with respect to the temperature distribution of the present embodiment, when the temperature of the central portion of the top plate 11 was 500 ° C., the peripheral portion was about 350 ° C. The temperature gradient in the outer peripheral area of the top plate 11 was 5 ° C./cm, which was a good result. On the other hand, as a comparative example, a dust collector having the same structure except that the current plate 14 was not provided was used. The conditions were the same as the above conditions. In the case of this comparative example, the temperature distribution was extremely low at the outer peripheral edge of the top plate 11 as shown by the temperature distribution characteristic tb, and was approximately 120 ° C. in the peripheral portion of the top plate 11. In this case, the temperature gradient was as high as 11 ° C./cm. In this comparative example, troubles such as deformation of the top plate and generation of cracks occurred.

As a result of repeating the above test, when the characteristic line (temperature change characteristic) shown in FIG. 5 is equal to or higher than the temperature distribution characteristic tc, that is, when the temperature gradient has a temperature distribution larger than this line tc, Troubles associated with deformation and damage of the top plate 11 frequently occurred. The temperature gradient of tc determined here was 9 ° C./cm. When the temperature gradient was smaller than the above, the trouble caused by the non-uniform temperature distribution of the top plate 11 could be greatly reduced.

Next, the temperature characteristics when the temperature of the high-temperature gas G is changed will be described with reference to a graph in which the temperature characteristics are also shown (the case where the gas temperature is 500 ° C. and 300 ° C.). The temperature distribution characteristic ta shown in FIG. 6 is a case where the gas temperature is 500 ° C., and is the same as that shown in FIG.
4 is good when the temperature gradient is 5 ° C / cm,
The temperature gradient when the current plate 14 is not provided is 11 ° C / cm.
Has also become. The temperature around the top plate 11 is controlled by the rectifying plate 14.
There is a difference of 230 ° C. between when and is not provided. Further, the temperature distribution characteristic tr shown in FIG. 6 is a temperature distribution characteristic when the temperature of the high-temperature gas G is set to 300 ° C. in the apparatus structure shown in this embodiment, and the temperature gradient is 1.6 ° C. /
cm. The temperature distribution characteristic ts is a temperature distribution characteristic when the temperature of the high-temperature gas G is set to 300 ° C. in a conventional structure (a structure without a current plate), and the temperature gradient is 5.9 °.
C / cm. In the temperature distribution characteristic tr, the top plate 11
Are averaged over a wide range, and the temperature gradient is small. The temperature of the peripheral portion of the top plate 11 depends on whether the current plate 14 is provided or not.
There is a 70 ° C difference. As described above, the hot gas G
Is 500 ° C. and the temperature distribution characteristic tr at 300 ° C. has a difference in the temperature gradient, but the temperature distribution of the top plate 11 is the temperature of the outer periphery of the top plate irrespective of the temperature of the hot gas G Are raised and averaged, and the temperature gradient tends to be small. Therefore, it can be understood that the structure shown in this embodiment is effective as a means for reducing the deformation and damage of the top plate 11 irrespective of the temperature of the high-temperature gas G. This is a dust collector capable of withstanding a sudden temperature change such as a gas temperature change of 300 ° C./h or more, and prevents the top plate and the filter element from being damaged regardless of the high temperature gas temperature change. This can contribute to increasing the production capacity of plants that emit gas.

After the dust collection process for the high-temperature gas G is completed, the high-pressure gas is ejected from the injection nozzle 13 into the discharge pipe 21 constituting the filter element 12 in the dust collection device 1 in this embodiment. As a result, the gas flows from the inside to the outside of the filter and blows out the dust remaining on the filter to the outside of the filter, contrary to the dust collection process. The blown-out dust is collected at the dust discharge port 6 by the funnel-shaped inclined portion at the lower part of the container body 2, and is discharged by opening the duct discharge port 6. The dust discharging operation is performed based on, for example, the amount of the high-temperature gas G collected or the operating time.

The mounting structure of the rectifying plate 14 is not particularly limited. In the case shown in FIGS. 1 to 3, the injection nozzles 13 and the plurality of rectifying plates 14 are alternately arranged in a substantially horizontal direction. The structure is fixed to the nozzle.
Further, the straightening plate 14 may be fixed to the top plate 11 or the container 2 via a suitable spacer or bracket, for example. Alternatively, for example, the current plate 14 may have a single-plate structure. In this case, the injection nozzle 13 may be fixed to the lower surface of the rectifying plate 14. In consideration of the piping of the injection nozzle 13, the single-type rectifying plate 14 is disposed below the injection nozzle 13. On the other hand, a structure having an opening that allows passage of the jet flow from the jet nozzle 13 may be simple.

The structure of the container body 2 is not limited to a square shape as in the present embodiment, but can be deformed as required, such as a cylindrical shape or a hexagonal shape. It can be changed appropriately according to the shape. In addition, although the straightening plate 14 shown in the drawing is simply a flat plate shape, a curved surface shape that appropriately changes the distance from the top plate 11 and a surface that is appropriately inclined due to the positional relationship with the discharge port 5 and the like are used. Structure may be provided. Further, the shape of the current plate 14 is, for example, inclined upward from the center to the outside (the distance from the top plate is gradually increased).
The shape may be a dished shape, in other words, a dish shape. The current plate 14 does not necessarily have a continuous structure, and may have a structure in which an opening or a notch is provided in the middle.

In the above-described embodiment, the discharge of the high-temperature gas g is performed by one discharge port 5, but the discharge port 5 on the secondary side is, for example, as shown in FIG. Thus, a configuration in which a plurality of outlets 5 are provided at a position close to the top plate 11 may be adopted. In this case, the flow of the high-temperature gas g along the top plate 11 can be created without the rectifying plate 14. The dust collector 1 shown in FIG. 4 has the same structure as that shown in FIG. 1 except that there is no current plate 14 and the configuration of the discharge port 5 is different. In this case, a configuration in which a rectifying plate 14 as shown in FIG. 1 may be provided. In a structure in which the position of the outlet 5 and the rectifying plate 14 are combined, the flow of the high-temperature gas is more effectively rectified. can do.

[0022]

As described above, the dust collecting device according to the present invention is provided.
Placement and dust collection method , on a top plate provided to close the gas passages such as high-temperature gas, provided a filter element that allows the hot gas to flow and filters dust in the high-temperature gas,
In addition, by rectifying the flow of the high-temperature gas filtered by the filter element so as to pass through a region of the top plate where the temperature is relatively low, the temperature distribution of the top plate due to the high-temperature gas is made uniform, and in particular, the temperature The temperature difference at the time can be suppressed. Therefore, the temperature of the top plate is such that the temperature difference between the central portion and the outer peripheral portion is small, and damage to the filter element fixed to the top plate and members related to the top plate as well as the top plate can be reduced. .

[Brief description of the drawings]

FIG. 1 is a schematic side view of a main part of a dust collector showing one embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a portion taken along line AA of the dust collecting device shown in FIG.

FIG. 3 is an enlarged side view of a main part of the dust collecting apparatus shown in FIG.

FIG. 4 is a schematic side view of a main part of a dust collector according to another embodiment of the present invention.

FIG. 5 is a temperature distribution characteristic diagram for comparing and explaining the temperature distribution.

FIG. 6 is a temperature distribution characteristic diagram showing temperature changes of high-temperature gases at different temperatures.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dust collection device 2 Container body 3A Primary side 3B Secondary side 4 Injection port 5 Discharge port 6 Dust discharge port 11 Top plate 12 Filter element 13 Injection nozzle 14 Straightening plate 15 Insertion hole 17 Discharge hole 21 Discharge pipe 22 Flange 23, 24 , 32 seal member 30 pressing part 33 compression spring 40 supporting part G hot gas before filtration g hot gas after filtration

Continuation of the front page (56) References JP-A-55-27018 (JP, A) JP-A-63-232817 (JP, A) JP-A-56-22622 (JP, A) , U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 46/02 B01D 46/24

Claims (4)

(57) [Claims] 1. A filter element is held and fixed by a top plate fixed to an inner wall of a container so as to define the inside of a container for dust collection into a primary side and a secondary side, and the filter element is supplied from the primary side. In the dust collection device in which the dust contained in the gas is filtered by passing the filtered gas through the filter element, on the gas discharge side of the filter element,
Rectifying means are provided for forming a temporarily along the flow the flow of gas in the secondary side with respect to the top plate, the temperature of the gas
A dust collecting apparatus for averaging the temperature of the top plate over the entire area . Wherein said rectifying means, the dust collecting apparatus according to claim 1, characterized in that it is constituted by a plate member provided so as to substantially face the gas discharge hole of the filter element. 3. The rectifying means is a plurality of gas outlets provided at positions offset on the outer peripheral side of the top plate so that the gas on the secondary side flows toward the outer peripheral side of the top plate. The dust collector according to claim 1, wherein: 4. Dust collection using the dust collection device according to claim 1.
A dust collection method .