JP3128261B2 - Backwashing device for hot gas duster and method for backwashing hot gas duster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention art INDUSTRIAL relates backwash process of the hot gas dust removal dexterity backwashing device and hot gas dust collector.

[0002]

2. Description of the Related Art Japanese Patent Publication Nos. 60-9843 and 63-4.
No. 0567 discloses a gas dust remover capable of continuously removing dust from a high-temperature gas. In these gas dust removers, a compressed gas is injected to generate a backwash gas flow, and the backwash gas flow is gas-discharged. A backwashing operation of regenerating a filter by sending it into a clean gas space of a dust remover and removing dust collected on the filter is performed intermittently.

[0003] That is, during the backwashing operation, the gas pressure on the clean gas space side of the dust remover temporarily increases, and the backwash gas flow flows in the filter wall in the opposite direction to the normal dust removal operation. As a result, the dust collected and accumulated on the filter surface is peeled off and dropped, and the filter is regenerated. This backwashing operation is sequentially repeated for the divided filter groups or dust removal chambers, and during this time, the dust collection operation is continuously performed in the other filter groups or dust removal chambers.

FIG. 3 shows an example of the configuration of a conventional backwashing apparatus in which a backwashing apparatus is attached to a gas duster of this type.
In the figure, 1 is a filter pipe (made of ceramics), 2 is a gas dust remover, 3 is a dust removal chamber, 4 is an ejector, 5 is a collecting pipe,
Reference numeral 6 denotes a compressed gas outlet, 9 denotes a compressed gas supply source (air compressor), 10 denotes a dust-containing gas inlet, 11 denotes a branch of a pipe, 13 denotes a hopper, 14 denotes a clean gas outlet, 15 denotes a dust cutoff valve, and 16 Is a high response speed valve.

In this case, the ejection of the compressed gas from the compressed gas outlet increases the backwashing effect, reduces the amount of backwash gas used, and minimizes the thermal shock applied to the ceramic filter tube. Various ideas have been elaborated. For example,
In order to increase the effect of backwashing, it is necessary to generate a high backwash gas pressure in a short time of 0.1 to 0.3 seconds, and to quickly raise the backwash gas pressure and shut off the compressed gas, Attach a high response speed valve to each compressed gas outlet, install a cylinder of compressed gas not too far from the backwashing device, use the ejector effect to filter and clean the outlet piping from the dust remover A method has been adopted in which a gas is swirled into a backwash gas stream, and at the same time, the temperature difference between the backwash gas stream and the dust-containing gas to be filtered is reduced.

However, the high response speed valve is not only expensive at least ten times the price of a general low response speed valve, but also has a small amount of compressed gas leakage even when the gas supply is shut off. The problem is that the consumption of compressed gas increases. The low response speed valve opens and closes quickly and the backwash gas pressure rises a little slower.Even when it closes, a considerable amount of compressed gas flows out by the time it closes completely, and the filter gas is exhausted by excessively flowing compressed gas. The filter tube is cooled, and there is a problem that the filter tube is damaged by a large thermal shock when the next operation proceeds to the dust removal operation.

Further, the high response speed valve is relatively defective.Ease
In the event of a leak due to failure, cool compressed gas
Normally uses compressed air) but flows out from the compressed gas outlet.
Continue to waste compressed gas and filter tube
Excessively cool the filter tube before moving to the dust removal operation.
Undesirable phenomena such as giving a large thermal shock
I have.

At present, dust removers of this type which can be used at a high temperature are used only for dust removal of exhaust gas when incinerating combustible waste contaminated with radioactive materials, but they are abundant. A gas that is indispensable for power generation using a pressurized fluidized bed combustion (PFBC) boiler, a next-generation low-pollution and high-efficiency power generation method that is currently being developed with the aim of using certain coal as an energy source One of the most promising candidates for dust removers is this type of gas remover,
(International Energy Agency) and the US Department of Energy (DO
E) by the trial Kemp programs have been conducted.

In the above-described power generation system, coal powder and limestone powder are charged into a pressurized fluidized bed combustion boiler, and during combustion, sulfur in the coal is combined with lime to be captured, and combustion is reduced by 8%.
Since the process proceeds at a relatively low temperature of about 50 ° C., generation of NO _X is small. At the same time when power generation by steam from the boiler, except for dust pressurized combustion gas of about 10-15 atmospheres,
Since the power generated by the gas turbine is generated by using the combustion gas obtained by filtering the dust, a high power generation efficiency can be obtained, so that the application is widespread, and improvement of this type of dust remover is desired.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a backwashing device for a gas duster and a method of backwashing the gas duster which can avoid the above-mentioned problems.

[0011]

The present invention SUMMARY OF] has been made to solve the problems described above, the hot gas dust dexterity backwash device of the present invention, the hot gas dust collector of ceramic fill <br/> data A backwashing device for regenerating a ceramic filter tube by removing dust collected on a tube surface by a backwash gas flow generated by injecting a compressed gas, comprising: a compressed gas supply source; An upstream valve that is a low response speed valve, a gas reservoir space,
A downstream valve, which is a high response speed valve, and a compressed gas jet port provided in a clean gas flow path from which filtered gas flows out are sequentially connected by a pipe.

[0012] <br/> high temperature dust-containing gas dedusting dexterity backwash equipment of the present invention, the downstream valve is a high response speed valve.

In another preferred embodiment of the backwashing device for a high-temperature dust-containing gas dust remover according to the present invention, a branch portion of a pipe is provided downstream of one upstream valve, and the downstream portion is connected to a plurality of downstream valves. I have.

In another preferred embodiment of the backwashing apparatus for a high-temperature dust-containing gas dust remover according to the present invention, the capacity of the gas storage space is a capacity for storing the compressed gas used for one backwashing.

In the backwashing device for a high-temperature dust-containing gas dust remover according to the present invention, two valves, a downstream valve and an upstream valve, are connected to a pipe connected to the compressed gas outlet, and a gas reservoir space is provided between the two valves. provided, opening and closing time is upstream valve are the least about 0.7 second low response speed valve, moreover use fast high response speed valve opening and closing time than the low response speed valve on the downstream side valve to a high response speed valve even if a little leak, substantially,
Leakage of compressed gas can be avoided by closing the upstream valve (low response speed valve).

That is, in the backwashing operation, first, the upstream side valve, which is a low response speed valve, is opened to open a gas storage space (a small-capacity cylinder or a large-sized pipe is used as a space having a required volume). The compressed gas necessary for one backwashing of the dust removal chamber is stored, and the upstream valve is closed, and then the downstream valve is opened.

In this case, when the downstream valve is a high response speed valve, preferably a high response speed valve whose opening and closing operation time is about 0.2 seconds or less, the gas pressure of the backwash gas flow rises rapidly,
Since the compressed gas stored in the gas storage space is released in a short time, no leak occurs unlike the case where only one high response speed valve is used.

Even if the high response speed valve fails,
By making it possible to exchange the valve in a short time and easily, it is possible to replace the failed downstream valve with the upstream valve closed while the dust collector is in use.

Next, when the downstream valve is a low response speed valve, the valve is operated in the same manner. First, the upstream valve is opened to store the compressed gas used for one backwash in the gas storage space. ,
After closing the upstream valve, open the downstream valve. In this case, the rise of the backwash gas pressure is not as rapid as when the high response speed valve is opened .

The ejection of the compressed gas from the compressed gas ejection port is as follows:
Following to the compressed gas which has been stored in the gas reservoir Me space is released, and then rapidly stopped.

[0021] When using only a low response speed valve as the valve is carried out an operation to close the Koben that has released the required time compressed gas, time is somewhat required for this closing operation, during which time a compressed gas low gas It will continue to flow under pressure. Compressed gas flowing in the low gas pressure is intended not necessary for backwashing addition to wasted compressed gas, in the case of dust from the hot dust containing gas, over-the ceramic filter tubes This causes cooling, and when returning to the dust collection operation after the backwashing operation, a large thermal shock may be applied to the ceramic filter tube to cause damage.

That is, the required opening / closing performance could not be obtained with the valve configuration including only the low response speed valve .

When the high-temperature gas dust remover includes a plurality of dust removal chambers, the backwashing is usually performed for each dust removal chamber sequentially.
It is made as to do. At this time, a dedicated compressed gas ejection port is provided for each dust removal chamber.
When such a dust remover is backwashed, in the present invention, only one upstream valve can be used in common. That is, a branch portion of a pipe is provided downstream of the upstream valve, and the downstream valve and the compressed gas ejection port are connected to the respective branched pipes. In this case, the gas storage spaces provided between the two valves are all used as a common space, so that one gas storage space can be shared.

Moreover, backwashing device of this configuration, it is possible to reduce the number of valves to be used, there is an advantage that smaller number of valves for opening and closing operations.

It is preferable to store the compressed gas required for one backwash in the gas storage space. In this case, it is possible to minimize the amount of the compressed gas used, and thus, the gas storage space is provided. The capacity of the compressor can be reduced and less energy is consumed for the backwash operation.

If the backwashing device is not effective, the pressure of the compressed gas used for backwashing is increased or the supply amount of the compressed gas is increased. It is also possible to increase / decrease the capacity of the gas reservoir space by opening / closing a separately provided valve by connecting a separately provided valve to a pipe between the upstream valve and the downstream valve, for example. In the above description, when opening the downstream valve has been described as performing the upstream valve from fully closed, it is also possible before the upstream valve is completely closed starts opening the downstream valve, the If even rather by by operating the valve so as not to flow unnecessarily compressed gas, it does not effect the aforementioned lost.

Even if the filter tube incorporated in the dust remover is a filter tube made of cordierite-based or silicon carbide-based ceramics having a low coefficient of thermal expansion and high thermal shock resistance, a large thermal shock Is repeatedly applied, the filter tube may be damaged. The backwashing device of the present <br/> invention to use the hot dust-containing gas as backwash device dedusting device for dedusting a readily be configured to use less compressed air, the valve has failed Leakage at the time can also be prevented, and as a result, thermal shock applied to the filter tube can be minimized.

The method for backwashing a high-temperature gas dust remover according to the present invention comprises, in order from the upstream, a compressed gas supply source, an upstream valve as a low response speed valve, a gas reservoir space, and a downstream side as a high response speed valve. state in which the valve, filtered gas and the compressed gas ejection port provided in the clean gas flow path for flowing out, the hot gas dust removal dexterity backwash device configured to be connected by piping, downstream valve is closed Backwash gas generated by opening the upstream valve and injecting the compressed gas into the gas storage space, closing the upstream valve, then opening the downstream valve and ejecting the compressed gas from the compressed gas outlet The flow is sent to a clean gas space of a high-temperature gas dust remover, and dust collected on the ceramic filter tube is removed to regenerate the ceramic filter tube .

[0029] Also in this backwash method, although the downstream valve with high response <br/> answer rate valve, and the effect in this case is the same as that of the backwash device described above.

The gas storage space preferably has a capacity for storing the compressed gas necessary for one backwashing operation. The backwashing device includes a plurality of compressed gas injection ports and a plurality of downstream valves. In both cases, the same number of upstream valves are connected and piped in parallel, and the case where a pipe branch is provided downstream of one upstream valve and connected to a plurality of downstream valves The advantages and disadvantages are as described above.

The case has been described utilizing the ejector effect as the compressed gas jets on than, ejector does not necessarily require a like gas dust collector of small capacity.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a backwashing device for a high-temperature gas dust remover according to the present invention will be described in detail with reference to the drawings of the embodiments, but the present invention is not limited to these embodiments.
FIG. 1 shows a backwashing apparatus having a typical configuration according to the present invention.
This is an example in which the apparatus is attached to a high-temperature gas dust remover 2 having two dust removal chambers 3.

In FIG. 1, the dust-containing gas entering the gas dust remover 2 from the dust-containing gas inlet 10 provided above the high-temperature gas dust remover 2 flows into the inside of the ceramic filter tube 1 from above, After being filtered by the filter pipe 1, it enters the clean gas space of the dust removal chamber 3, and is discharged from the clean gas outlet 14 through the collecting pipe 5. On the other hand , the dust is a filter tube 1 made of ceramics.
The dust is collected and deposited on the inner surface of the hopper, and a part of the deposited dust is spontaneously separated, falls, and moves to the hopper 13.

However, a lot of dust accumulates on the inner surface of the filter tube 1 one after another, and the accumulated dust gradually increases the ventilation pressure loss of the filter tube, eventually losing the filter function of the filter tube. The backwashing device is a device for removing the dust from the filter tube 1 and transferring it to the hopper 13, and at the same time, regenerating the filter function of the filter tube.

In the backwashing apparatus shown in FIG. 1, the ejector 4, the compressed gas outlet 6, the downstream valve 8, the gas storage space 12, and the upstream valve 7 correspond to each of the three dust removal chambers 3. 3 but respectively, are connected by piping in parallel, they are consolidated in further pipe into one compressed gas supply source 9, the upstream valve 7 is in the low-response rate valve, downstream valve
8 is a high response speed valve.

The backwashing operation is sequentially performed for each of the dust removal chambers 3, and during this time, the dust removal operation is continued in the other dust removal chambers 3.

First, the case where the first (for example, upper) dust removing chamber 3 is backwashed to regenerate the filter 1 therein will be described. All the downstream valves 8 and all the upstream valves 7
Starts from the closed state, and first, the upstream upstream valve 7
Is opened, and the compressed gas used for one backwash is introduced into the gas storage space 12 from the compressed gas supply source 9 (in most cases, compressed air such as a compressor is used).

Next, when the upstream valve 7 is closed and the downstream upper valve 8 is opened, the compressed gas stored in the gas storage space 12 is ejected from the compressed gas outlet 6 and the surrounding gas is discharged by the ejector. , A pulse flow of the backwash gas is formed, and is sent into the upper dust removal chamber 3. At this time, the backwash gas pressure in the clean gas space of the upper dust removal chamber 3 becomes higher than the gas pressure inside the filter tube 1, and the gas flows through the filter wall of the filter tube 1 in a direction opposite to that in a normal dust collection operation. The dust that has accumulated on the inner surface of the filter tube 1 is separated by the backwash gas flow, and falls into the hopper 13 in the filter tube 1 to regenerate the filter tube 1. When the gas stored in the gas storage space 12 has been discharged, the downstream valve 8 is closed.

When the dust accumulated in the hopper 13 has accumulated to a certain extent, the cutout valve 15 is opened and the dust is appropriately taken out. Next, the gas dust remover 2 is continuously used without interruption by performing the same backwashing operation on the second dust removal chamber 3 and the third dust removal chamber 3. Downstream valve 8 Ri high response speed valve der,
Since the low response speed valve is connected in series as the upstream valve 7, even if there is a leak which is a disadvantage of the high response speed valve, the leak is prevented if the low response speed valve of the upstream valve 7 is closed, Compressed gas is not wasted.

A low response speed valve is provided as the upstream valve 7.
Thereby, even when the high response speed valve of the downstream valve 8 fails, a large amount of the compressed gas flows into the dust removal chamber 3 due to the leak from the failed valve and wastefully consumes the compressed gas.
The filter tube 1 is excessively cooled by the flow of compressed gas, then when moving to dust removal operation, there is no and benzalkonium damage the filter tubes 1 gives greater thermal shock to the filter tube 1.

Since the gas pressure in the dust removal chamber is usually low,
For example, by inserting a blind plate downstream of the downstream valve 8, it is possible to replace the failed downstream valve 8 with the upstream valve 7 closed.

[0042] When the downstream-side valve 8 is a low response speed valve, the rising speed of the backwash gas pressure rapid is not name as in the case of using the high response speed valve.

[0043] However, the low response speed valve is inexpensive and 1 or less is 10 minutes compared to the high response speed valve price, whereby the whole back washing apparatus as compared with the case of using the high response speed valve Ahn <br /> Ru can be formed in value.

FIG. 2 shows that the low response speed valve, which is the
In this example, the number of valves to be operated is reduced.
2 is connected to a plurality of downstream valves 8 at the downstream side of the pipe, and the operation method is the same as that of FIG.
The effect of adopting the configuration of FIG. 1 is almost the same as that of FIG. 1, but only when the compressed gas is stored in the gas storage space because the high response speed valve is used for the downstream valve 8. In addition, there is a little leakage of the compressed gas from all the high response speed valves, and it is difficult to replace the failed high response speed valve because it is necessary to stop all the backwashing operations when replacing the high response speed valve.

In FIG. 2, only one gas storage space 12 is provided upstream of the plurality of downstream valves 8, and each of the dust removal chambers 3 is provided.
Will function as a common gas reservoir space 12 when backwashing.

Test Example In order to examine the practical performance of the backwashing device for a gas duster and the backwashing method of the gas duster according to the present invention, a backwashing test was conducted using the following test device. The test apparatus has one dust chamber with a diameter of 2.3 m and 37 ceramic filter tubes (outer diameter 170 mm, inner diameter 140 mm, length 3) in one dust chamber.
00 mm), the effective filtration area of this dust removal chamber is 4.9 m ² , and the space volume on the clean gas side is 1.08 m ³ .

In this test apparatus, the internal pressure of the clean gas side space of the dust removal chamber was set to normal pressure, the conditions of the valve configuration and the presence or absence of the gas storage space were changed, and a compressed gas (air) supply source of 6 atm was used. Was sent to an ejector, air was ejected from a compressed gas ejection port to generate a backwash gas flow, which was injected into a dust removal chamber, and a backwash test was conducted in which the dust removal chamber was backwashed at 3 minute intervals.

The pipe of this test backwashing apparatus has an inner diameter of 4
A tank having an inner volume of 0.15 m ³ was connected to the pipe as a gas storage space. The ejector has an inner diameter of 120 mm for the constricted portion and an inner diameter of 240 m for the expanded portion.
m, length 1200 mm, compressed gas outlet 30 m
m.

All the valves are for 40 mm pipes, and the low response speed valve used is an open / close operation time of 0.7 seconds made by Kitamura Co., and the high response speed valve is made of Keihin Co., Ltd. The one having a time of 0.2 seconds was used. However, in this high response speed valve, the closed state and the open state
It is specified that there is a% leak.

In this backwashing device, the distance from the valve (the downstream valve when the downstream valve is provided) to the tip of the compressed gas outlet was 70 cm.

In the case of a backwashing apparatus using an upstream valve and a downstream valve in combination, the upstream valve is opened to store the compressed gas in the gas storage space, the upstream valve is closed, and then the downstream valve is opened. In the case of a single-valve backwashing device with a high response speed valve, the operation interval of closing → opening → closing is set to 0.3 seconds. The backwashing test was performed at room temperature with the operation interval of closing → opening → closing being 0.8 seconds. The pressure of the backwash gas stream was measured in the clean gas space of the dust removal chamber, and the results of the tests performed are summarized in Table 1.

[0052]

[Table 1]

As a result of the above test, the amount of the compressed gas used in one backwash operation was 0.53 N in the case of (1).
m ³ , 0.2 Nm ³ in the case of (2), and 0.2 Nm ³ in the case of (3).
2 nm ^3, was 0.3 Nm ³ in the case of (4). (1)
In the case of (1), it is clear that the compressed gas is consumed more by the amount of time for which the backwash gas pressure decreases. Assuming that the backwashing operation by the backwashing device is performed once every 10 minutes for each dust removal chamber, the backwashing operation of (3) and (4) is compared with that of the conventional backwashing device (2). It was found that the consumption of the compressed gas in the case can be reduced to about half.

Further, by using a high response speed valve as the downstream valve and using a low response speed valve as the upstream valve, leakage of the compressed gas could be almost eliminated. Also, it was confirmed that when a highly reliable low response speed valve was used for both the upstream side valve and the downstream side valve, the rising speed of the backwash gas pressure was low . The backwashing device, if the high gas pressure in the dust chamber of the dust collector also can perform backwashing in the same manner by relatively high compression gas pressure and the temperature of the dust containing gas is high order, can be carried out since the amount of compressed gas used is small, the backwash operation without excessively cooling the filter tubes.

[0055]

In the backwashing apparatus for a high-temperature dust remover according to the present invention, the waste of the compressed gas due to the leak of the high response speed valve for supplying the compressed gas to the compressed gas ejection port or the leak when the high response speed valve fails. and thermal shock damage problems due to subcooling of the filter tube is resolved, in a more preferred embodiment thereof, the exchange can and <br/> ing when a high response speed valve has failed.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a high-temperature gas dust remover to which a backwash apparatus as a typical example of the present invention is attached.

FIG. 2 shows a backwash apparatus according to another embodiment of the present invention.
The schematic sectional drawing of a high-temperature gas dust remover.

FIG. 3 is a schematic cross-sectional view of a high-temperature gas dust remover equipped with a conventional backwashing device.

[Explanation of symbols]

1: Filter tube 2: High-temperature gas dust remover 3: Dust removal chamber 4: Ejector 5: Collecting pipe 6: Compressed gas jet port 7: Upstream valve 8: Downstream valve 9: Compressed gas supply source (air compressor) 10: Dust-containing gas inlet 11: Branch of piping 12: Gas reservoir space 13: Hopper 14: Clean gas outlet 15: Dust extraction valve 16: High response speed valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Toriyama 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Asahi Glass Co., Ltd. (72) Inventor Tatsuya Yoshioka 6-15-1, Ginza, Chuo-ku, Tokyo Power development shares In-company (72) Inventor Hideki Goto 6-15-1, Ginza, Chuo-ku, Tokyo Power Supply Development Co., Ltd. (72) Inventor Tetsuya Kunitaka 6-15-1, Ginza, Chuo-ku, Tokyo Power Supply Development Co., Ltd. ( 56) References JP-A-60-64614 (JP, A) JP-A-61-268331 (JP, A) JP-A-61-268330 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) B01D 46/00-46/54

Claims (2)

(57) [Claims] 1. A ceramic filter for a high-temperature gas dust remover.
A backwashing device for regenerating a ceramic filter tube by removing dust collected on a tube surface by a backwash gas flow generated by injecting a compressed gas, comprising: a compressed gas supply source; An upstream valve that is a low response speed valve, a gas reservoir space,
A high- temperature gas characterized in that a downstream valve that is a high response speed valve and a compressed gas jet port provided in a clean gas flow path from which filtered gas flows out are sequentially connected by a pipe. Backwashing device for dust remover. 2. In order from the upstream, a compressed gas supply source, an upstream valve as a low response speed valve, a gas storage space, and a high response speed
And the downstream valve is a valve, and filtered compressed gas port where the gas is provided in the clean gas flow path for flowing out, the hot gas dust removal dexterity backwash device configured to be connected by piping, downstream Opening the upstream valve with the valve closed, injecting compressed gas into the gas reservoir space, and then closing the upstream valve, then opening the downstream valve and causing compressed gas to be ejected from the compressed gas outlet. the tightening backwash gas stream, play ceramic full <br/> filter tube dislodge dust collected on the ceramic fill <br/> data pipe on by feeding a clean gas space of the hot gas dust collector Backwashing method of a high-temperature gas duster.