JP2005169326A - Filter washing apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter washing method for effectively washing a filter element. <P>SOLUTION: The filter washing apparatus comprises a washing liquid transport part (including a washing tool 8, a washing liquid pressure gauge 9, a check valve 10, a washing liquid pipe 12, and a washing liquid pump 13) for transporting a washing liquid from a downstream side to a filter element (2); a first buffer tank (20) for stagnating the washing liquid and a pressurized gas; and a second buffer tank (21) for stagnating a pressurized gas having a pressure higher than that of the washing liquid. Pressure is intermittently applied to the first buffer tank (20) by the pressurized gas in the second buffer tank (21), so that the washing liquid in the first buffer tank (20) is intermittently force fitted to the washing liquid washing the filter element (2), as a result, the pressure of the washing liquid washing the filter element (2) can intermittently be increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a filter cleaning device, and more particularly to a filter element cleaning device that removes dust by filtering dust-containing gas through a porous filter.

  2. Description of the Related Art Porous (porous) filters that remove dust by filtering porous gas using porous ceramic or metal are used. An overview of the porous filter in operation is described with reference to FIG.

A plurality of filter elements 2 are installed on the filter tube plate 5 in the pressure vessel 1. The filter element 2 has a cylindrical shape (hollow cylindrical shape, conical shape, box shape), and is attached to a hole of the filter tube plate 5 so that a gap is formed between the filter tube plate 5 and the gas so as not to bypass.
The filter element 2 is made of a porous material typified by ceramic or metal, and dust is filtered and removed when dust-containing gas passes through the holes.

During operation, the dust-containing gas is injected from the dust-containing gas inlet nozzle 3, and the dust-containing gas is removed through the filter element 2 and is discharged from the clean gas outlet nozzle 4 as a clean gas. At this time, dust adheres to the outer surface of the filter element.
When a porous filter is used for a long time, the adhering dust increases, the hole becomes clogged, and the pressure loss increases, so it is necessary to clean the filter element regularly.

During operation, a method of backwashing with a high-pressure inert gas or the like from the downstream (clean) side of the filter element 2 may be used. However, the cleaning of the filter element 2 for fundamentally restoring the capacity of the increase in pressure loss due to clogging over time during operation is performed when the operation is stopped.
As a typical cleaning method, there are a method of opening the manhole 6, removing the filter element 2, cleaning with a water jet outside the pressure vessel 1, and cleaning with a cleaning liquid. Depending on the adhered substance, a cleaning solution for removing the adhered substance is used.

  Since removing the filter element 2 requires labor, a method of cleaning without removing the filter element 2 may be employed. A conventional method for cleaning without removing the filter element 2 is shown in FIG. A cleaning jig 8 is attached to the upper part of the filter element 2 and the cleaning liquid is caused to flow from the downstream (clean) side of the filter in the normal operation by the cleaning liquid pump 13, thereby removing the dirt on the filter element 2. The cleaning liquid after cleaning is discharged from the drain nozzle 7 to the drain tank.

As the cleaning liquid, it is preferable to use a liquid that has a higher density and viscosity than gas and has a cleaning effect.
An invention relating to a cleaning liquid is disclosed in Patent Document 1.
JP-A-5-309221

A method for improving the cleaning power in combination with a high-pressure gas is disclosed in Patent Document 2.
Patent Document 3 discloses a method in which cleaning water and compressed air are supplied simultaneously to generate a jet water flow for cleaning.
JP-A-5-285354 Japanese Patent Publication No. 7-63569

Usually, the total flow rate of the cleaning liquid is not controlled or determined by the discharge flow rate of the cleaning liquid pump used. In this case, the pressure applied to the filter element 2 decreases with a decrease in dirt.
In a state where the pressure is reduced, the pressure applied to the dirt clogging the pores is small, and the flow rate of the cleaning liquid in the pores of the filter element 2 is also reduced, so that the cleaning efficiency is lowered.
Further, in the case of normal cleaning, there is no sudden fluctuation in the pressure of the cleaning liquid.

In order to increase the cleaning efficiency, it is desirable to increase the pressure of the cleaning liquid.
In order to maintain the cleaning liquid pressure high even if a part of the dirt is removed, the cleaning liquid pump 13 having a sufficient capacity is required. However, increasing the capacity of the cleaning liquid pump 13 increases equipment and installation costs.

  An object of the present invention is to provide a filter cleaning method for effectively cleaning a filter element.

  Hereinafter, means for solving the problem will be described using the numbers and symbols used in [Best Mode for Carrying Out the Invention]. These numbers and symbols are added to clarify the correspondence between the description of [Claims] and the description of [Best Mode for Carrying Out the Invention]. It should not be used to interpret the technical scope of the invention described in “

  The filter cleaning apparatus according to the present invention intermittently increases the pressure of the cleaning liquid that is continuously passed through the filter element (2) to be cleaned.

  The filter cleaning device intermittently raises the pressure of the cleaning liquid using pressurized gas.

The filter cleaning apparatus according to the present invention includes a cleaning liquid transfer section that continuously transfers the cleaning liquid from the downstream side to the filter element (2), and a pressurizing section that pressurizes the cleaning liquid intermittently with pressurized gas.
The cleaning liquid transfer unit includes a cleaning jig (8), a cleaning liquid pressure gauge (9), a check valve (10), a cleaning liquid pipe (12), and a cleaning liquid pump (13). The pressurizing unit includes a first buffer tank (20), a second buffer tank (21), a compressor (22), a first valve (23), a second valve (24), a third valve (25), and a pressurized gas. It includes a pressure gauge (26), an arithmetic unit (27), and a level gauge (28) (of the first buffer tank).

The filter cleaning apparatus according to the present invention includes a cleaning liquid transfer unit (cleaning jig 8, cleaning liquid pressure gauge 9, check valve 10, cleaning liquid pipe 12, cleaning liquid pump, and the like that continuously transfers the cleaning liquid from the downstream side to the filter element (2). 13), a first buffer tank (20) in which a cleaning liquid and a pressurized gas are stored, and a second buffer tank (21) in which a pressurized gas having a pressure higher than that of the cleaning liquid is stored.
The pressurized gas in the second buffer tank (21) applies pressure to the first buffer tank (20) intermittently, and the cleaning liquid in the first buffer tank (20) is cleaned with the cleaning liquid for cleaning the filter element (2). The pressure of the cleaning liquid for cleaning the filter element (2) is intermittently increased by press-fitting into the filter intermittently.

  The filter element that is cleaned by the filter cleaning device is a porous filter element that is installed in a filter that filters out dust in the dust-containing gas and removes the dust.

  The filter cleaning method of the present invention intermittently increases the pressure of the cleaning liquid that is continuously passed through the filter element (2) to be cleaned.

  In the filter cleaning method, the pressure of the cleaning liquid is intermittently increased by the pressurized gas.

  The present invention can provide a filter cleaning method for effectively cleaning a filter element.

Embodiments of a porous filter cleaning device according to the present invention will be described below with reference to the accompanying drawings.
The porous filter of this embodiment is installed upstream of the gas turbine in the process of supplying combustible gas generated by gasifying coal to the gas turbine in the coal gasification combined power generation apparatus, and removes dust in the combustible gas. However, the present invention is not limited to this type.

An overview of the porous filter cleaning of the present invention will be described with reference to FIG.
The porous filter cleaning method of the present invention improves the cleaning performance by intermittently changing the pressure of the cleaning liquid applied to the filter element for cleaning with pressurized gas.

  The porous filter includes a pressure vessel 1, a filter element 2, a dust-containing gas inlet nozzle 3, a clean gas outlet nozzle 4, a filter tube plate 5, a manhole 6, and a drain nozzle 7.

  The pressure vessel 1 is a container for the outer shell of a porous filter, and is manufactured to withstand internal pressure. FIG. 1 shows a vertical pressure vessel in which the upper head portion has a flat hemispherical shape, the barrel portion has a cylindrical shape, and the lower head portion has a conical shape facing downward. The shape is not limited.

  The filter element 2 is made of a porous material typified by ceramic or metal, and has a cylindrical shape (including a hollow cylindrical shape, a box shape, and a conical shape). The filter element 2 is attached to the hole of the filter tube plate 5 with the opening portion at the top so that a gap is formed between the filter element 2 and the dust-containing gas. When the dust-containing gas passes from the outside to the inside of the filter element 2 through the pores, the dust is filtered and removed.

  During operation, the dust-containing gas is injected from the dust-containing gas inlet nozzle 3, and the clean gas filtered by the filter element 2 is discharged from the clean gas outlet nozzle 4.

  The filter tube plate 5 is a plate having a body cross-sectional shape installed so as to divide the inside of the pressure vessel 1 horizontally. A space between the filter tube plate 5 and the inner wall of the pressure vessel 1 is sealed by welding or packing. The filter tube plate 5 is provided with a hole for attaching the filter element 2. The filter tube plate 5 is installed so as to withstand the weight of the filter element 2 or the pressure difference generated in the filter element 2.

The manhole 6 is an opening for allowing a person to enter the tank for maintenance while the porous filter is stopped, or for carrying the cleaning jig 8 and the cleaning liquid pipe 12 into the porous filter. The removed filter element may be carried out / in from the manhole 6. The manhole 6 is closed with a manhole cover during operation.
In FIG. 1, the manhole 6 is attached to the top of the head, but is not limited to the top as long as it is above the filter tube plate 5.

  The drain nozzle 7 is a nozzle for discharging the cleaning liquid (drain liquid) after cleaning. The drain nozzle 7 is usually installed at the lowermost part of the pressure vessel 1.

  The porous filter cleaning device includes a cleaning jig 8, a cleaning liquid pressure gauge 9, a check valve 10, a cleaning liquid pipe 12, a cleaning liquid pump 13, a first buffer tank 20, a second buffer tank 21, a compressor 22, a first valve 23, a first 2 valves 24, a third valve 25, a pressurized gas pressure gauge 26, a computing device 27, and a level gauge 28 (of the first buffer tank).

The cleaning liquid pump 13 and the cleaning jig 8 are connected by a cleaning liquid pipe 12. A check valve 10 is installed on the cleaning liquid pipe 12. The cleaning liquid pipe 12 between the check valve 10 and the cleaning jig 8 is branched and connected to the lower nozzle of the first buffer tank 20.
The upper nozzle of the first buffer tank 20 and the second buffer tank 21 are connected by a pressurized pipe L1. The 1st valve | bulb 23 is installed on the pressurization piping L1. The pressurization piping L1 between the first valve 23 and the first buffer tank 20 is branched, and the second valve 24 is installed. One of the second valves 24 is opened to the atmosphere. The first valve 23 and the second buffer tank 21 are branched and a third valve 25 is installed. One of the third valves 25 is opened to the atmosphere. A pressurized gas pressure gauge 26 is installed in the second buffer tank 21 or the pressurized pipe L <b> 1 between the first valve 23 and the second buffer tank 21. The 2nd buffer tank 21 and the compressor 22 are installed by the pressurization piping L2.

The cleaning jig 8 is a jig for connecting the cleaning liquid pipe 12 and the filter element 2. The cleaning jig 8 is installed so that the cleaning liquid flows from the downstream side (clean side / inside) to the filter element 2. The cleaning jig 8 is attached so that the cleaning liquid does not leak from between the filter element 2 or the filter tube plate 5 even when a predetermined pressure is applied. The cleaning jig 8 may have a shape that covers all the filter elements 2 or a shape that allows the cleaning liquid to flow through a plurality of or one filter element 2. In the case of a shape in which the cleaning liquid is allowed to flow through the plurality of filter elements 2, the connection portion of the cleaning jig 8 with the filter element 2 may be branched so as to be connected to each filter element 2, or can be supplied to the plurality of filter elements 2. Shape may be sufficient.
The number of filter elements 2 to be cleaned at a time is related to the capacity of the cleaning liquid pump 13, the pressure to be cleaned, and the size of the filter element 2.

  The cleaning liquid pressure gauge 9 is installed on the cleaning liquid pipe 12 between the check valve 10 and the cleaning jig 8, detects the pressure of the cleaning liquid pressed into the filter element 2, and transmits the detection result to the arithmetic device 27.

  The check valve 10 is installed on the cleaning liquid pipe 12 and prevents the cleaning liquid from flowing back to the cleaning liquid pump 13. In the present invention, since the cleaning liquid is pressurized with gas, it is possible to prevent the cleaning liquid pump 13 from being pressurized from the discharge side.

  The cleaning liquid pipe 12 is a pipe that connects the cleaning liquid pump 13 and the cleaning jig 8 to transfer the cleaning liquid. A cleaning liquid pressure gauge 9 and a check valve 10 are installed in the middle of the cleaning liquid pipe 12. Further, a pipe connected to the lower nozzle of the first buffer tank 20 branches downstream of the check valve 10.

  The cleaning liquid pump 13 is a pump for press-fitting the cleaning liquid into the filter element 2. As long as the cleaning liquid can be injected at a target pressure, the pump is not limited to a pump, and a cleaning liquid tank installed at a high place can also be used.

The first buffer tank 20 is a pressure vessel having a certain capacity. The lower nozzle of the first buffer tank 20 is connected to the cleaning liquid pipe 12 downstream of the check valve 10. An upper nozzle of the first buffer tank 20 is connected to the second buffer tank 21 by a pressurized gas pipe L 1, and a first valve 23 is installed between the first buffer tank 20 and the second buffer tank 21.
A level meter 28 is installed in the first buffer tank 20 and transmits level information to the arithmetic unit 27.
In the first buffer tank 20, the cleaning liquid and the pressurized gas are balanced with the first valve 23 closed. By opening the first valve 23, the first buffer tank 20 is pressurized by the pressure of the pressurized gas in the second buffer tank 21. At this time, the cleaning liquid in the first buffer tank is pushed out, and the cleaning liquid applied to the filter element 2 is pressurized.

  The second buffer tank 21 is a pressure vessel having a certain capacity. The second buffer tank 21 stores the pressurized gas from the compressor 22 and pressurizes the first buffer tank 20 by opening the first valve 23.

  The compressor 22 pressurizes the gas and transfers it to the second buffer tank 21. The gas may be air or an insoluble gas in a cleaning liquid such as an inert gas. The cylinder is not limited to the compressor 22 as long as pressure can be applied.

  The first valve 23 is a control valve and is installed between the first buffer tank 20 and the second buffer tank 21. When the first valve 23 is opened, the first buffer tank 20 is pressurized with the pressure of the second buffer tank 21. The opening and closing of the first valve 23 is controlled by the arithmetic unit 27 according to the value of the level meter 28, the value of the cleaning liquid pressure gauge 9, or a predetermined time.

The second valve 24 is a control valve for adjusting the pressure of the first buffer tank 20, and is installed between the atmosphere and the first buffer tank 20. In FIG. 1, the pressurized gas pipe L1 between the first buffer tank 20 and the first valve 23 is branched, and the second valve 24 is installed. The second valve 24 is controlled by the arithmetic unit 27.
When the first valve 23 is closed and the cleaning liquid level of the first buffer tank 20 is lowered below a predetermined value, the second valve 24 is opened to adjust the cleaning liquid level of the first buffer tank 20 and the first valve 23 is opened. The gas in the buffer tank 20 is vented. When the level of the cleaning liquid in the first buffer tank 20 rises to a predetermined level, the second valve is closed.

  The third valve 25 is a control valve for adjusting the pressure of the second buffer tank 21, and is installed between the atmosphere and the second buffer tank 21. In FIG. 1, the pressurized gas pipe L1 between the second buffer tank 21 and the first valve 23 is branched, and a third valve 25 is installed. In order to adjust the pressure of the second buffer tank 21, it is opened and closed by the value of the pressurized gas pressure gauge 26. The pressure in the second buffer tank 21 is determined so that the pressure is not applied to the filter element 2 when the first valve 1 is opened. The third valve 25 may be a spring-type pressure regulating valve that discharges pressurized gas to the atmosphere when the pressure exceeds a certain level.

  The pressurized gas pressure gauge 26 measures the pressure of the second buffer tank 21 with a pressure gauge. The measurement result of the pressurized gas pressure gauge 26 is used for controlling the third valve 25.

The computing device 27 controls the opening and closing of the first valve 23 and the second valve 24 based on the detection values of the cleaning liquid pressure gauge 9 and the level gauge 28.
The arithmetic unit 27 closes the first valve 23 when the value of the cleaning liquid pressure gauge 9 has increased to a predetermined value or when the value of the level gauge 28 has decreased to a predetermined value, and the value of the cleaning liquid pressure gauge 9 has a predetermined value. The first valve 23 is opened when the pressure drops to the lower limit. The opening and closing of the first valve 23 may be adjusted with time.
Further, when the first valve 23 is closed and the level of the cleaning liquid in the level meter 28 is lowered to a predetermined level, the arithmetic unit 27 opens the second valve in order to raise the liquid level to the predetermined level. .

  The level meter 28 measures the level of the cleaning liquid in the first buffer tank 20. When the first buffer tank 20 is pressurized, the liquid level is adjusted so that the pressurized gas does not enter the cleaning liquid flowing in the filter element 2. There is no particular problem even if the pressurized gas flows into the cleaning liquid and the filter element 2.

  The drainage tank 15 is a container for storing the drainage discharged from the porous filter.

(Description of operation)
Next, the operation of the porous filter cleaning device of the present invention will be described.

The cleaning liquid is continuously pumped to the filter element 2 by the cleaning liquid pump 13.
At this time, the first valve 23 is intermittently opened and closed, so that the pressure of the second buffer tank 21 is applied to the first buffer tank 20, the cleaning liquid in the first buffer tank is pushed out, and the pressure of the cleaning liquid is increased. Rise. If the pressure of the cleaning liquid pressure gauge 9 increases to a predetermined value, or if the liquid level of the first buffer tank 20 decreases to a predetermined value, the first valve 23 is closed by the arithmetic unit 27. Alternatively, the first valve 23 is closed at a predetermined time.

At this time, the pressure applied to the filter element 2 rapidly increases and decreases gently when the first valve 23 is opened as shown in the upper diagram of FIG.
Thus, when the pressure applied to the filter element 2 changes, when the pressure increases, the pressure is applied to the dirt of the filter element 2 and the pressure increases rapidly, and the dirt is peeled off by the impact. As shown in the lower diagram of FIG. 2, when the pressure increases, the contamination coefficient of the filter element 2 rapidly decreases.

  When the first valve 23 is closed, the pressurized gas is again stored in the second buffer tank 21 from the compressor 22. The pressure of the second buffer tank 21 is adjusted by the pressurized gas pressure gauge 26 and the third valve 25 so that an appropriate pressure is applied to the cleaning liquid when the first valve 23 is opened. Specifically, the appropriate pressure is determined by the allowable pressure of the filter element 2 and the like.

  If the liquid level of the first buffer tank 20 is lower than the predetermined value when the first valve 23 is closed, the second valve 24 is opened by the control unit 27 and the pressurized gas in the first buffer tank 20 is changed. Released into the atmosphere, the level of cleaning liquid rises.

A suitable pressure gas is stored in the second buffer tank 21, and the first valve 23 is opened again in a state where the liquid level of the first buffer tank 20 reaches a predetermined value.
The above steps are repeated.

  As described above, the pressure of the cleaning liquid can be changed by opening and closing the first valve 23. By repeatedly opening and closing the first valve 23, the cleaning effect is improved.

  In the above porous filter device, since the cleaning liquid is pressurized with a pressurized gas in addition to the pressurization of the cleaning liquid pump 13, the capacity of the cleaning liquid pump 13 can be reduced.

  Further, since gas is used for pressurizing the cleaning liquid, each buffer tank can be made small, and unnecessary impacts can be absorbed.

In the above porous filter cleaning apparatus, the pressure of the cleaning liquid applied to the filter element 2 rises intermittently.
Usually, the pressure of the cleaning liquid is not controlled at the time of cleaning, and cleaning may be continued in a state where the pressure is reduced to a pressure that is not effective for cleaning.
Specifically, in the method of continuously flowing the cleaning water, the pressure of the filter element 2 is high at the start of cleaning with a lot of dirt, so the pressure of the cleaning liquid is high. The pressure loss of the filter element 2 decreases, and the pressure applied to the filter element 2 decreases. Even if cleaning is continued as it is, the flow rate concentrates on the part where the dirt is removed, and the pressure is reduced. Therefore, the pressure applied to the dirt clogged in the pores of the filter element 2 is lowered. The speed of the cleaning liquid passing through becomes slower. For this reason, the cleaning effect decreases.

The filter cleaning apparatus of the present invention increases the cleaning liquid pressure that has a correlation with the pressure of the cleaning liquid applied to the pores of the filter element 2 and the flow rate of the cleaning liquid passing through the pores. Further, intermittently changing the pressure can be expected to have a detergency due to the shock.
Furthermore, since the pressure pressurized by the pressurized gas is applied, the capacity of the cleaning liquid pump can be reduced as compared with the case of using only the cleaning liquid pump.

In the above embodiment, a porous filter for removing dust from combustion gas of a coal gasification combined power generation device is illustrated as a porous filter using the porous filter cleaning device of the present invention. This porous filter is a large-scale device in which hundreds of elements having a diameter of several tens of centimeters and a length of several meters are incorporated. For this reason, it is economically expensive to take out the element in the apparatus from the filter every time it is cleaned. Therefore, an effective cleaning method with the above elements installed has an economic effect. large.
In addition, the method of cleaning by intermittently pressurizing the cleaning liquid has a larger cleaning effect than the case of continuously pressurizing, and is effective in removing difficult dirt and shortening the cleaning time.

In the above-described embodiment, the porous filter for removing dust from the combustion gas of the coal gasification combined power generation device is exemplified as the porous filter using the porous filter cleaning device of the present invention. However, the porous filter is not limited to this type of porous filter. Any filter can be used as long as it uses a filter element and a filter medium that can withstand a constant backwash pressure.
Specifically, the present invention can be applied to a dust removal filter for pressurized fluidized bed, a candle type porous filter for dust removal, and the like.

  Furthermore, the method of cleaning the filter element 2 by changing the pressure of the cleaning liquid according to the present invention can be applied even when the filter element 2 is removed from the porous filter body for cleaning.

It is a schematic diagram of Embodiment 1 of the porous filter washing | cleaning of this invention. It is a graph which shows the relationship between the pressure applied to a filter element, and a dirt coefficient. It is an outline figure at the time of operation of a porous filter. It is an outline figure of washing of the conventional porous filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Filter element 3 Dust-containing gas inlet nozzle 4 Clean gas outlet nozzle 5 Filter tube plate 6 Manhole 7 Drain nozzle 8 Cleaning jig 9 Cleaning liquid pressure gauge 10 Check valve 12 Cleaning liquid piping 13 Cleaning liquid pump 15 Drain 20 Buffer tank 21 Second buffer tank 22 Compressor 23 First valve 24 Second valve 25 Third valve 26 Pressurized gas pressure gauge 27 Computing device 28 (first buffer tank) Level meter

Claims (7)

The pressure of the cleaning liquid that is continuously flowed to the filter element to be cleaned is intermittently increased.
Filter cleaning device. Increasing the pressure of the cleaning liquid intermittently with pressurized gas,
The filter cleaning apparatus according to claim 1. A cleaning liquid transfer section for continuously transferring the cleaning liquid from the downstream side to the filter element;
A pressurizing unit that intermittently pressurizes the cleaning liquid with gas;
Comprising
Filter cleaning device. A cleaning liquid transfer section for continuously transferring the cleaning liquid from the downstream side to the filter element; a first buffer tank in which the cleaning liquid and pressurized gas are stored;
A second buffer tank in which the pressurized gas having a pressure higher than that of the cleaning liquid is stored;
Comprising
Intermittently pressurizing the first buffer tank with the pressurized gas in the second buffer tank, and intermittently press-fitting the cleaning liquid in the first buffer tank into the cleaning liquid for cleaning the filter element; And intermittently increasing the pressure of the cleaning liquid for cleaning the filter element,
Filter cleaning device. The filter element is a porous filter element that is installed in a filter that removes dust by filtering dust-containing gas dust.
The filter cleaning apparatus according to claim 1. The pressure of the cleaning solution that is continuously flowed to the filter element to be cleaned is intermittently increased.
Filter cleaning method. Increasing the pressure of the cleaning liquid intermittently with pressurized gas,
The filter cleaning method according to claim 6.

Images