JP3064144B2 - Dust remover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing dust-containing gas discharged from a combustion facility, a steel plant, a cement plant, a chemical plant, or the like using fossil fuel such as coal.

[0002]

2. Description of the Related Art FIG.
It is sectional drawing which shows an example of the conventional dust removal apparatus which removes the dust in a high temperature gas. In this conventional dust removing apparatus, a plurality of porous ceramic tubes 01 are arranged along the flow direction of a dust-containing gas. That is, each porous ceramic tube 0
Numerals 1 are arranged along the flow direction of the dust-containing gas in a can body 02 arranged substantially vertically. And this can 02
The dust-containing gas that has flowed into the can body 02 from the dust-containing gas inlet 03 at the top of the tube flows into each of the porous ceramic tubes 01 and is removed in the process of passing from the inside to the outside through the tube walls, and the clean gas is removed. And flows out from the clean gas outlet 04. on the other hand,
The dust removed from the gas is guided to the dust hopper 05 below the can 02 and discharged. The upper and lower ends of each porous ceramic tube 01 are supported by tube sheets (partition plates) 06, respectively.

In the conventional dust removing apparatus shown in FIG. 7, dust may adhere and accumulate on the inner surface of the ceramic tube 01 for filtration. By injecting high-pressure backwash air intermittently from the outer peripheral side, the attached dust is separated from the inner surface and dropped downward.

[0004] However, if backwashing is performed simultaneously over the entire range, a disturbance is given to the downstream side using the clean gas due to its pressure fluctuation or temperature fluctuation.
There is a problem in that the ratio of the separated dust in the entire portion to be backwashed trapped on the dust-containing gas side and re-adsorbed in the next filtration step increases.

FIG. 8 is a cross-sectional view of another example of a conventional dust removing device using a porous ceramic tube for removing dust in a high-temperature gas. In this dust removing device, a plurality of porous ceramic tubes 012 having both ends open are disposed substantially vertically inside a can body 011 in two stages, and the upper and lower ends thereof are supported by tube sheets 013, respectively. The interior of the can body 011 is partitioned into an upper space 015 communicating with an upper dust-containing gas inlet 014, a central space 017 communicating with a clean gas outlet pipe 016 in an intermediate portion, and a lower space 019 communicating with a lower dust hopper 018. ing. The dust-containing gas 020 such as a boiler combustion gas is removed while passing from the inside to the outside of each ceramic tube 012, and flows from each clean gas outlet tube 016 to the clean gas tube 21.

Further, in order to remove dust adhering to the ceramic tube 012, high-pressure air for back washing is supplied from a compressed air source 02.
2, the gas is intermittently supplied through a backwash valve 023 and an air pipe 024, and is injected from a nozzle 025 through a clean gas outlet pipe 016 into a central space 017 of a can body 011.

In the conventional dust removing apparatus shown in FIG. 8, however, the plurality of ceramic tubes 012 are constituted only by open ends, and the clean gas from which dust has been removed is drawn out horizontally through the ceramic tube wall. 9 (A to D) at the lowermost portion (outlet) D of each ceramic tube.
As shown in FIGS. 8A to 8D, there is no downward gas flow, the dust separated and dropped at the upper part of the ceramic tube is stagnated, and the ash treatment device located downstream of the dust hopper 018 (Not shown). In an extreme case, there is a concern that the ceramic tube may be blocked by dust. Furthermore, if abnormal combustion occurs in an upstream boiler or the like and dust containing unburned material stalls at the lowermost end of the ceramic tube, a post-burning phenomenon or the like may occur when the backwash air is supplied.

Therefore, as a conventional example which solves these problems, there is one disclosed in Japanese Patent Publication No. 3-24251. In this conventional example, as shown in FIG. 10, in order to secure a gas flow at the lowermost end portion of a ceramic tube 012, a lower space 019 of a can body 11 is moved from an upper space 01 to a lower space 01.
5, a dust-containing gas circulation line 046 is provided, and a circulation pump 047 is provided in this line. Note that FIG.
In FIG. 8, the same portions as those shown in FIG. 8 are denoted by the same reference numerals, and duplicate description will be omitted.

However, the conventional example shown in FIG. 10 has the following problems. That is, there is no circulating pump capable of withstanding a high-temperature gas of 850 ° C., and practical use is difficult. Further, even if it can be put to practical use, the efficiency of the dust removing device itself is reduced by circulating the gas.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and does not give a disturbance due to a pressure fluctuation or a temperature fluctuation to a downstream side of using a clean gas, so that a circulation line and a circulation It is an object of the present invention to provide a dust removing device that does not require a special device such as a pump, secures a dust-containing gas flow near the lowermost end of a ceramic tube, and reduces dust accumulation on the inner surface of the ceramic tube.

[0011]

The dust removing device of the present invention takes the following measures.

(1) Dust-containing gas is disposed almost vertically and the upper part is
The upper pipe is placed inside the can body, the lower part of which is connected to the dust hopper at the inlet.
Has a plate and a lower tube plate and a plurality of porous ceramic bodies cylindrical filter element and the O <br/> Ri constructed filter element group mounted between them, the fill
Between the upper tube sheet and the lower tube sheet of the
From the upper tube sheet to the lower tube sheet into a clean gas chamber formed and containing a clean gas passing through the cylindrical filter element.
And the cylindrical filter element is divided into a plurality of groups to divide the clean gas chamber into a plurality of chambers, and each of the divided chambers has a common clean gas through an independent outlet pipe. Connected to the mother pipe and
A backwash device for each group of the cylindrical filter elements is provided immediately before the outlet pipe joins the clean gas mother pipe.

(2) In the dust removal apparatus of the above (1), the operation time period and the operation frequency of the backwashing device for each filter element group are made different at least.

(3) An upper pipe is provided in a can body which is disposed substantially vertically and has an upper portion connected to a dust-containing gas inlet and a lower portion connected to a dust hopper.
Plate and lower tube sheet and multiple perforations mounted between them
With a cylindrical ceramic filter element
One composed filter element groups Ri, or the full
The filter element group is transferred from the upper tube sheet to the lower tube sheet.
Multiple by dividing by the inner cylinder bulkhead provided
A dust filter for backwashing the filter element group with backwash air, wherein a honeycomb type filter element made of a porous ceramic body is attached to a lower surface of the lower tube sheet; Ha said honeycomb <br/> filter element is provided for accommodating the cleaning gas filtration
Characterized in that communicates with the clean gas chamber for honeycomb type filter element clean gas chamber for accommodating the filtered clean gas cylindrical Fi <br/> Luther elements of the filter elements belonging to the mounting site.

[0015]

In the present invention of the above (1), the clean gas chamber is
A cylindrical inner cylinder partition wall extending from the upper tube sheet to the lower tube sheet is provided.
Divided into multiple chambers by a cylindrical filter
One element without dividing the element in the height direction
And is divided into a plurality of groups consisting of the inner tube unit and the outer tube bundle in a circle just before the confluence of the respective chambers clean gas main pipe of the outlet tube
It is connected to the clean gas main pipe by an independent outlet pipe provided with a backwashing device for each group of cylindrical filter elements . As a result, the filter element groups in the inner tube group and the outer tube group can be backwashed independently, and when dust removal (filtration) is performed in one of the chambers, the backwash is performed in another chamber. it is possible to perform simultaneously cleaning variations in gas pressure and temperature are significantly scaled down, and their confinement of the dust to the dust-containing gas side is prevented.

In the present invention of (2), since at least one of the operation time period and the operation frequency of the backwashing device is made different, the fluctuation of the clean gas pressure and the temperature and the dust-containing gas The accumulation of dust on the side is more effectively reduced and prevented.

In the present invention (3), the dust-containing gas
Is a cylindrical filter element made of a porous ceramic body
The gas flows into the element from the upper end of the filter, flows downward while being filtered, and the gas flow rate decreases toward the lower end.
Hani the lower surface attached porous ceramic body of the tube plate
Dust is removed and filtered by a cam type filter element.
Thereby, even in the lowermost end of the cylindrical filter element flows downward dust containing gas is ensured, the moth
The flow of dust promotes the discharge of dust to the dust hopper,
Adhesion of dust near the lower end of cylindrical filter element
Concerns about the occurrence of defects due to growth, stagnation of dust, etc. are eliminated. Also attached to the lower surface of the lower tube sheet
Honeycomb filter element that contains the clean gas filtered by the selected honeycomb filter element
Use clean gas chamber is in communication with the clean gas chamber of the cylindrical filter <br/> over elements belonging to the mounting part, it becomes that the backwashing is carried out simultaneously with the cylindrical filter element group, another reverse Dust can be effectively removed without providing a washing device .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. In the first embodiment, as shown in FIG.
A single filter element composed of a plurality of cylindrical porous ceramics filter elements in a can body 1 installed substantially vertically, having a dust-containing gas inlet 2 at the top and a dust hopper 3 at the bottom connected Groups are provided. The filter element group includes a plurality of cylindrical filter elements 4 made of a porous ceramic body fixed or gripped by an upper tube sheet 6, a lower tube sheet 7 and two intermediate tube sheets 8, as shown in FIG. of there inner cylinder partition wall 5, the inner cylinder partition wall 5, as shown in FIG. 3, a plurality of cylindrical filter element 4 in cross-section of the filter element groups
With the outer cylindrical filter element 4A and the inner cylinder
It is divided into two tube groups with the mold filter element 4B. At the same time, the inner cylinder partition wall 5, the cylindrical upper tube sheet 6 on the outside of the filter element 4, the lower tube plate 7, the intermediate tube plate 8 and consists of the can body 1 a cylindrical filter element 4
The clean gas chamber on the secondary side is also divided into two.

Two clean gas outlet pipes 9A are provided at the same height as the two intermediate tube plates 8 and open to the side wall of the can body 1. The clean gas outlet pipes 9A are located outside the can body 1. The clean gas chamber formed outside the inner cylinder partition wall 5 is connected to the clean gas mother pipe 19 via the clean gas outlet pipe 9A. A clean outlet pipe 9B concentrically opening into the inner cylinder partition wall 5 in each of the clean gas outlet pipes 9A.
The clean gas outlet pipe 9B is connected to a gas mother pipe 19, and a clean gas chamber formed inside the inner cylinder partition wall 5 is connected to the clean gas outlet pipe 9B via the clean gas outlet pipe 9B.
9 is connected. As described above, the clean gas outlet pipes 9A and 9B that lead each of the divided clean gas chambers to the clean gas main pipe 19 are configured as concentric double pipes, and are connected until they are connected to the clean gas main pipe 19. , Are independent of each other.

At a position immediately before connection to the clean gas mother pipe 19, a backwashing device 15A for the outer tube group and a backwashing device 15B for the inner tube group are installed in the respective clean gas outlet tubes 9A and 9B. In addition, backwash control valves 14A and 14B and backwash nozzles 16A and 16B are provided respectively, and backwash air is supplied from a common high pressure air source 18 via an air pipe 17.

Reference numeral 10 denotes a manhole provided in the can body 1 and the dust hopper 3, reference numeral 11 denotes a manhole provided in the inner cylinder partition wall 5, and a cylindrical filter element 4 corresponds to FIG.
As shown in the figure, a walkway 13 is formed in this portion of the intermediate tube sheet 8 and the lower tube sheet 7 without being disposed over an appropriate width in the diametric direction from the manhole 11 to the clean gas outlet pipe 9B.

In this embodiment, the can 1
The dust-containing gas that has flowed into the filter element enters the cylindrical filter element 4, flows from the inside toward the outside, removes dust, and stores the clean gas in each of the clean gas chambers divided by the inner cylinder partition wall 5. The clean gas flows into the common clean gas mother pipe 19 via the clean gas outlet pipes 9A and 9B and is sent to downstream equipment. On the other hand, the dust captured in each cylindrical filter element 4 falls and is stored in the dust hopper 3.

Further, the backwashing devices 15A and 15B of the clean gas outlet pipes 9A and 9B are operated to operate the backwash nozzle 1
By blowing backwash air from 6A and 16B, backwashing of the outer cylindrical filter element 4A and the inner cylindrical filter element 4B is performed independently.

In this embodiment, as described above, the inner cylindrical partition wall 5
The clean gas chamber is divided into two parts, and each of the divided clean gas chambers is provided with a backwashing device 15A, 15A provided before the junction of the independent gas outlet pipes 9A, 9B to the clean gas mother pipe 19.
Since the backwashing can be independently performed by B, the backwashing devices 15A and 15B are operated after setting the time zone and frequency appropriately, and dust is removed in one clean gas chamber and the other is cleaned in the other clean gas chamber. By performing backwashing, fluctuations in clean gas pressure and fluctuations in temperature can be greatly reduced. Also,
By performing dust removal in one clean gas chamber, even when backwashing is performed in the other clean gas chamber, the behavior of dust on the dust-containing gas side can be reduced.

Note that the division of the filter element group
From two tubes consisting of an inner tube group and an outer tube group of the embodiment to three or more
If it increases , the fluctuation of the gas pressure and temperature of the clean gas can be further reduced, and the behavior of the dust on the dust-containing gas side can be stabilized.

FIGS. 4 to 6 show a second embodiment of the present invention.
It will be explained by. This embodiment is obtained by further adding the configuration described below to the first embodiment, and the same parts in FIGS. 4 to 6 are denoted by the same reference numerals as in FIGS. 1 to 3. The description is omitted.

In this embodiment, a filter element 22 of a honeycomb type porous ceramic body is attached to the lower surface of the lower tube sheet 7. The filter Jer of the can body 1 as
Corridor in the lower tube plate 7 as inspection space placement group 13
The honeycomb-type filter element 22 is mounted directly below the walkway 13 because no cylindrical element is disposed in this portion. In this embodiment, since the clean gas chamber is divided into two by the inner cylinder partition wall 5, as shown in FIG. 5, four honeycomb filter elements 22 are installed in each clean gas chamber. The number of the honeycomb type filter elements 22 may be only two at the diagonal part, or may be other numbers.

As shown in FIG. 6, the ceramic body mounting portion 19 penetrates through the lower tube sheet 7 and is mounted on the lower tube sheet 7.
Filter elements 22 of the honeycomb type porous ceramic body is mounted on, Hani the honeycomb filter element 22 is provided with clean gas that has been filtered to suck dust containing gas from the lower part of the ceramic body mounting portion 19
It is housed in a clean gas chamber 20 for a cam type filter element , and this clean gas chamber 20 for a honeycomb type filter element belongs to a cylinder of a section (part) to which it belongs via a clean gas outlet 21 provided in a ceramic body mounting portion 19. It is connected to the clean gas chamber of the mold filter element group .

In this embodiment, similarly to the first embodiment, the dust-containing gas flowing into the can 1 enters the cylindrical filter element 4 of a porous ceramic body and flows from the inside to the outside. Although it becomes a clean gas, the dust-containing gas emitted from the lower end of the cylindrical filter element 4 is removed by the honeycomb-type porous ceramics filter element 22 to become a clean gas, and the honeycomb-type filter element
After passing through the clean gas chamber 20 for use , it flows into the clean gas chamber of the cylindrical filter element group of the section to which it belongs.

Further, the hitting the backwash, the honeycomb full <br/> I Luther element 22, high pressure air for backwash from the clean gas chamber of the filter element groups sections belonging is supplied, the filter element Backwashing takes place simultaneously with the group of cylindrical filter elements 4.

In this embodiment, the cylindrical filter element 4 made of a porous ceramic body of the filter element group is used.
The amount of gas at the outlet at the lower end is not equal to 0 but equal to the amount of filtered gas of the honeycomb filter element 22 . FIG. 9 shows an example of the gas flow velocity distribution of the conventional dust removing apparatus as described above. In the present embodiment, FIG.
The flow velocity at a point changes from 0 to a finite value, for example, about 0.5 m / s, and accordingly, the gas velocity is added to each upstream point by this difference. By increasing the flow rate of the dust-containing gas in the downward direction, the fall of the dust is urged, and the reliability and function of the dust removing device can be greatly improved during dust removal (filtration) and during backwashing. .

[0032]

As described above, according to the first and second aspects of the present invention, the clean gas chamber is moved from the upper tube sheet to the lower tube sheet.
By providing a cylindrical inner cylinder partition wall,
Divided into cylindrical filter elements in the height direction
The inner tube group and the outer tube group can be
Divided into several groups, each chamber being a clean gas
Immediately before the junction with the pipe, each of the cylindrical filter elements
Equipped with a backwash unit for the group, and a separate cleaning pipe
The inner tube group, outer tube group, etc.
Backwash the filter elements in each chamber independently
It can, also the working hours of the backwash device of the cylindrical filter element of the clean gas chamber, by varying the frequency, is carried out dust in either chamber (filtration)
Sometimes it is possible to backwash in another room, which is a problem
Clean gas pressure and temperature fluctuations and at the time of backwashing, which has been a, including
This has the effect of significantly improving the accumulation of dust on the dust gas side and the reattachment of dust accompanying simultaneous backwashing of the cylindrical filter element.

According to a third aspect of the present invention, an upper tube sheet, a lower tube sheet and a space between them are provided in a can body having a substantially vertical arrangement, an upper portion connected to a dust-containing gas inlet and a lower portion connected to a dust hopper.
Filter et constituted by a cylindrical <br/> filter element of a plurality of porous ceramic material which is attached to
One Remento group, or before the same filter element groups
Inner cylinder bulkhead provided from upper tube sheet to lower tube sheet
In the dust removing apparatus having a plurality of groups by dividing the filter element group and back-washing the filter element group with back-washing air, the dust-containing gas is supplied from an upper end of a cylindrical filter element of a porous ceramic body. Filter inside the element
While flowing downward, and the gas flow velocity decreases toward the lower end.
Although it is lowered, the porous ceramic body
Honeycomb filter element is installed
So dust is included in the honeycomb filter element
The gas is removed and filtered to form a cylindrical filter.
Even at the bottom of the element, a downward dust-containing gas flow
This gas flow ensures that dust is discharged to the dust hopper.
Is promoted, near the lower end of the cylindrical filter element
Failure due to dust growth on dust, stagnation of dust, etc.
Concerns can be resolved. In addition , the lower tube sheet
Filtered by the attached honeycomb filter element
Honeycomb filter element for storing clean gas
The clean gas chamber for components is a cylindrical type belonging to the installation site.
It communicates with the clean gas chamber of the filter element group,
The backwash is performed simultaneously with the cylindrical filter element group
And remove dust without installing a separate backwashing device.
It can be done effectively. Furthermore, since there is no need for a dust-containing gas circulating device, particularly a circulating pump that withstands a high temperature of about 850 ° C., as in the related art, the dust removing device can be simplified, and a decrease in efficiency due to circulation can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall side view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a detailed sectional view of a main part of the embodiment.

FIG. 4 is a schematic sectional view of a second embodiment of the present invention.

FIG. 5 is a sectional view taken along the line BB of FIG. 4;

FIG. 6 is a detailed sectional view of a portion of a lower tube sheet of the embodiment.

FIG. 7 is a sectional view of an example of a conventional dust removing device.

FIG. 8 is a sectional view of another example of the conventional dust removing device.

9 is a view showing a gas flow velocity distribution inside a ceramic tube of the dust removing apparatus shown in FIG.

FIG. 10 is a sectional view of still another example of the conventional dust removing device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 can 2 dust-containing gas inlet 3 dust hopper 4 cylindrical filter element 5 inner cylinder partition 6 upper tube sheet 7 lower tube sheet 8 intermediate tube sheet 9A, 9B clean gas outlet pipe 14A, 14B backwash control valve 15A, 15B reverse washing device 16A, 16B backwash nozzles 17 air tube 18 source of high pressure air 19 cleaning gas main pipe 19 Qing ceramics body mounting portion 20 honeycomb filter element <br/> Kiyoshi gas chamber 21 clean gas outlet 22 honeycomb full I Luther element

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisataka Urata 1-1, Akunouramachi, Nagasaki-shi Inside Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Tetsuya Fujino 1-1-1, Akunouramachi, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. (56) References JP-A-4-326916 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 46/00-46/54 B01D 39/20

Claims (3)

(57) [Claims] 1. A dust-containing gas inlet disposed substantially vertically and having an upper portion.
In the can body, the lower part of which is connected to the dust hopper,
Have constructed filter element group by the cylindrical filter element of the lower tube plate and a plurality of porous ceramic material mounted therebetween, the filter
An element group is formed between the upper tube sheet and the lower tube sheet.
From the upper tube sheet to the lower tube sheet into the clean gas chamber containing the clean gas passing through the cylindrical filter element.
Min the clean gas chamber into a plurality of chambers and provided with a barrel inner cylinder partition wall to partition the said cylindrical filter element into a plurality of groups
It was split, wherein each of the divided chambers are connected to a common clean gas main pipe by independent outlet pipe, and each of the cylindrical filter just before the confluence into the clean gas main pipe of said outlet tube A dust removing device comprising a backwash device for each group of elements. 2. The dust removing device according to claim 1, wherein at least one of the operation time period and the operation frequency of the backwashing device for each filter element group is different. 3. A can body, which is arranged substantially vertically and has an upper portion connected to a dust-containing gas inlet and a lower portion connected to a dust hopper, and
Lower tube sheet and multiple porous cells attached between them
Composed of Lamix cylindrical filter element
One filter element group to be made, or the same fill
The filter element group extends from the upper tube sheet to the lower tube sheet.
Group by dividing by inner cylinder bulkhead provided
As has, in filtration apparatus for backwashing the filter element groups by backwash air, fitted with a honeycomb filter element of a porous ceramic body to a lower surface of the lower tube plate, the honeycomb disposed in the lower tube plate Hanika that holds the clean gas filtered by the filter element
A dust removing device, wherein a clean gas chamber for a filter element of a cylindrical type is communicated with a clean gas chamber for storing clean gas filtered by a cylindrical filter element of the filter element group belonging to the mounting portion.