JP6664847B2 - Control device and control method of compressed air injection operation in dust collector - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a control device and a control method of a compressed air injection operation in a dust collector used for treating exhaust gas discharged from various industrial devices.

Exhaust gas discharged from various industrial devices, particularly exhaust gas discharged from a device involving combustion, contains gaseous substances such as HCl and SOx and other reactive substances in addition to dust.
Since these substances are harmful to the human body, it is required to remove them from the exhaust gas, and many exhaust gas treatment apparatuses have been put to practical use.

  One of them is to introduce an exhaust gas into a treatment chamber in which a cylindrical filter cloth is disposed, and to react a harmful gas component contained in the exhaust gas with a neutralizing agent on the surface of the cylindrical filter cloth to obtain a neutralizing reactant. A dust collector has been proposed and practically used to remove from exhaust gas together with dust and the like by forming the dust.

  By the way, in the above dust collector, the neutralizing reactant formed on the surface of the filter cloth is deposited on the surface of the filter cloth together with the dust and the like, and this deposit increases the ventilation resistance of the filter cloth and lowers the processing capacity of the dust collector. Therefore, it is necessary to remove the sediment trapped on the surface of the filter cloth every predetermined time or when the airflow resistance increases.

  On the other hand, in the technical field of dust collectors, as shown in FIG. 6, a venturi tube 11A is disposed at the opening of the filter cloth 1 as a wiping mechanism for wiping off the sediment trapped on the surface of the filter cloth. A type in which compressed air of 0.2 to 0.6 MPa is supplied from a nozzle 3 formed of a flat hole provided in an injector pipe 2 to the inside of a filter cloth 1 via a venturi tube 11A is widely used (for example, And Patent Documents 1 and 2.)

  An air supply unit 4 for supplying compressed air to the injector pipe 2 includes a branch pipe 41 for storing compressed air supplied from a compressor (not shown), and a full-body type pulse valve 42 connected to the branch pipe 41. The compressed air stored in the branch pipe 41 is supplied to the injector pipe 2 connected to the pulse valve 42 via the pulse valve 42.

JP-A-8-299732 JP-A-11-244634

By the way, the above-mentioned general-purpose payment mechanism has the following problems.
In the case of a system in which compressed air is supplied from the nozzle 3 having a flat hole provided in the injector pipe 2 to the inside of the filter cloth 1 via the venturi tube 11A, the compressed air flows through the Venturi tube 11A having a narrow flow path. In order to generate a pressure loss when passing through the filter cloth and to reduce the rate of pressure rise in the filter cloth due to the compressed air, high-pressure compressed air of 0.2 to 0.6 MPa is required.
The compressed air ejected from the nozzle 3 having a flat hole provided in the injector pipe 2 diffuses rapidly once, is rectified when passing through the venturi pipe 11A, and becomes a laminar flow state. In addition, a problem that the deposits cannot be evenly removed easily occurs.
The full-body type pulse valve 42 that is easily available and easy to assemble has a large internal pressure loss and a low response speed, and thus tends to cause a problem that deposits cannot be evenly removed.

  In view of the problems of the above-mentioned conventional general-purpose wiping mechanism, the applicant of the present application first used a relatively low-pressure compressed air to provide a filter cloth capable of uniformly wiping the sediment. An exhaust gas treatment device used was proposed (Japanese Patent Application No. 2015-69304).

  The present invention provides a technique of the exhaust gas treatment apparatus capable of solving the problems of the conventional general-purpose sweeping mechanism, that is, using a relatively low-pressure compressed air to evenly remove the sediment. In addition, it is possible to obtain the effect of improving the operation efficiency of the dust collector, the effect of promoting the neutralization reaction, the effect of reducing the amount of the neutralizing agent used, the effect of saving energy, and the effect of improving the durability of the filter cloth. It is an object of the present invention to provide a control device and a control method for a compressed air injection operation in a dust collector.

  In order to achieve the above object, a control device for a compressed air injection operation in a dust collector of the present invention reacts a harmful gas component contained in exhaust gas with a neutralizing agent on the surface of a cylindrical filter cloth to neutralize a reactant. And removing the neutralizing reactant present on the surface of the filter cloth by pulsating compressed air into the opening of the filter cloth while removing the neutralized reactant from the exhaust gas by forming the filter cloth. In the control device for the air injection operation, the control device may set a differential pressure value of the filter cloth, which is a trigger of the compressed air injection operation, based on a concentration of a harmful gas component contained in the exhaust gas. A differential pressure value change setting means is provided which changes and sets the reference differential pressure value in the range of the reference concentration of the gas component to a differential pressure value different from the reference differential pressure value.

  In this case, the differential pressure value change setting means changes and sets the differential pressure value of the filter cloth, which triggers the compressed air injection operation, to a first differential pressure value higher than the reference differential pressure value. Can be provided.

  Further, the differential pressure value change setting means has a function of changing and setting a differential pressure value of the filter cloth, which is a trigger of a compressed air injection operation, to a second differential pressure value lower than the reference differential pressure value. You can be.

  Further, the method for controlling the compressed air injection operation in the dust collector according to the present invention comprises reacting a harmful gas component contained in the exhaust gas with a neutralizing agent on the surface of the cylindrical filter cloth to form a neutralizing reactant. In addition to removing from the exhaust gas, the compressed air injection operation in the dust collector to blow off the neutralized reactant present on the surface of the filter cloth by pulsating the compressed air to the opening of the filter cloth. In the control method, when the concentration of the harmful gas component contained in the exhaust gas becomes higher than a preset reference concentration range of the harmful gas component, the difference between the filter cloth that triggers the injection operation of the compressed air. The pressure value may be set higher than a preset reference differential pressure value in the range of the reference concentration.

  In this case, when the concentration of the harmful gas component becomes higher than the reference concentration range, the amount of the neutralizing agent supplied to the surface of the filter cloth can be kept unchanged.

  Further, the method for controlling the compressed air injection operation in the dust collector according to the present invention comprises reacting a harmful gas component contained in the exhaust gas with a neutralizing agent on the surface of the cylindrical filter cloth to form a neutralizing reactant. In addition to removing from the exhaust gas, the compressed air injection operation in the dust collector to blow off the neutralized reactant present on the surface of the filter cloth by pulsating the compressed air to the opening of the filter cloth. In the control method, when the concentration of the harmful gas component contained in the exhaust gas becomes lower than the preset reference concentration range of the harmful gas component, the difference in the filter cloth that triggers the compressed air injection operation is determined. The pressure value is set to be lower than a preset reference differential pressure value in the range of the reference concentration.

  In this case, when the concentration of the harmful gas component becomes lower than the range of the reference concentration, the amount of the neutralizing agent supplied to the surface of the filter cloth can be reduced.

  According to the control device and the control method of the compressed air injection operation in the dust collector of the present invention, the harmful gas component contained in the exhaust gas is reacted with the neutralizing agent on the surface of the cylindrical filter cloth to form a neutralizing reactant. By removing the neutralized reactant present on the surface of the filter cloth by injecting compressed air into the opening of the filter cloth in a pulsed manner, The compressed air supplied to the filter cloth can be introduced from the opening of the cylindrical filter cloth into the filter cloth without causing a pressure loss, and the pressure rising speed in the filter cloth is maintained up to the tip of the filter cloth. For example, by using compressed air (0.1 MPa <P <0.2 MPa) set at a relatively low pressure P, the sediment trapped on the surface of the filter cloth can be evenly removed.

  Then, the control device sets the differential pressure value of the filter cloth, which triggers the injection operation of the compressed air, to a predetermined reference concentration range of the harmful gas component based on the concentration of the harmful gas component contained in the exhaust gas. And a differential pressure value change setting means for changing and setting the reference differential pressure value to a differential pressure value different from the reference differential pressure value, wherein the concentration of the harmful gas component contained in the exhaust gas is set in advance. If the harmful gas component becomes higher than the reference concentration range, the differential pressure value of the filter cloth, which is a trigger of the compressed air injection operation, is set to a predetermined reference differential pressure value in the reference concentration range. By setting it higher than that, it is possible to prevent the interval of the compressed air injection operation from becoming shorter due to the rising gradient of the differential pressure value of the filter cloth due to the increase in the concentration of the harmful gas component. The effect of improving the operation efficiency of the dust collector , It can be obtained neutralization reaction acceleration effect, a reduction effect and filter cloth durability improvement effect of the amount of neutralizing agent.

  In this case, when the concentration of the harmful gas component becomes higher than the range of the reference concentration, the amount of the neutralizing agent supplied to the surface of the filter cloth is not changed, thereby further neutralizing. The effect of reducing the use amount of the agent can be obtained.

  On the other hand, when the concentration of the harmful gas component contained in the exhaust gas becomes lower than the preset reference concentration range of the harmful gas component, the differential pressure value of the filter cloth which triggers the injection operation of the compressed air. Is set lower than the preset reference differential pressure value in the range of the reference concentration, thereby increasing the gradient of the differential pressure value of the filter cloth due to the decrease in the concentration of the harmful gas component. By suppressing the interval of the compressed air injection operation from becoming extremely long due to the decrease, the neutralization reaction promoting effect and the energy saving effect can be obtained.

  In this case, when the concentration of the harmful gas component is lower than the range of the reference concentration, the amount of the neutralizing agent supplied to the surface of the filter cloth is reduced to further neutralize the filter cloth. The effect of reducing the use amount of the agent can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of one embodiment of a dust collector to which the present invention is applied, (a) is an overall view, and (b) is a cross-sectional view of an injector pipe. It is explanatory drawing of the air supply part of the same dust collector, (a) is sectional drawing which shows the state in which the pulse valve was closed, (b) is sectional drawing which shows the state in which the pulse valve was opened. It is explanatory drawing of the compressed air flow path connected from an injector pipe to a nozzle. FIGS. 4A and 4B are explanatory diagrams of a mechanism for removing the sediment trapped on the surface of the filter cloth. FIG. 4A shows the case of a conventional dust collector, and FIG. 4B shows the case of the dust collector of the present invention. It is a flowchart which shows one Example of the control method of the injection operation of the compressed air in the dust collector of this invention. It is explanatory drawing of the conventional dust collector, (a) is an overall view, (b) is sectional drawing of an injector pipe.

  Hereinafter, embodiments of a control device and a control method of a compressed air injection operation in a dust collector of the present invention will be described with reference to the drawings.

  1 and 2 show one embodiment of a dust collector to which the present invention is applied.

  This dust collector introduces exhaust gas discharged from various industrial equipment such as a refuse incinerator into a processing chamber 5 in which a cylindrical filter cloth 1 is disposed, and removes harmful gas components such as HCl and SOx contained in the exhaust gas. By reacting with the neutralizing agent on the surface of the cylindrical filter cloth 1 to form a neutralizing reactant, it is removed from the exhaust gas together with dust and the like.

  More specifically, the dust collector includes a cylindrical filter cloth 1 disposed in a processing chamber 5 into which exhaust gas is introduced (for example, disposed in a matrix), and a neutralizing agent applied to the surface of the filter cloth 1. For example, compressed air (0.1 MPa <P) set at a relatively low pressure P is introduced into a neutralizing agent introducing section (not shown) for supplying a neutralizing agent for attachment and an opening 11 of the cylindrical filter cloth 1. <0.2 MPa) from the nozzle 3 provided in the injector pipe 2 by directly injecting and supplying in a pulsed manner so that the deposit containing the neutralizing reactant trapped on the surface of the filter cloth 1 is wiped off. The air supply unit 4 is provided.

  Here, "directly" injecting and supplying the compressed air means that the filter cloth in the open state is used without using the venturi tube 11A disposed in the opening 11 of the filter cloth 1 in the conventional general-purpose sweeping mechanism. This means that injection and supply are performed without interposing an object in one opening 11.

In this case, as shown in FIG. 3A, the compressed air flow path 31 connected from the injector pipe 2 to the nozzle 3 may have a uniform cross-sectional area, but FIG. As shown in the drawing, by giving a radius R or by giving a chamfer C as shown in FIG. 3 (c), the shape is gradually reduced from the injector pipe 2 side toward the tip end side of the nozzle 3. Is preferable.
Thereby, the compressed air is straightened from the nozzle 3 and jetted out, so that the straightness is high, and the pressure rising speed in the filter cloth 1 is maintained up to the tip of the filter cloth 1, so that the compressed air is captured on the surface of the filter cloth 1. The deposited sediment can be washed off evenly.

In particular, the nozzle 3 provided in the injector pipe 2 is oriented such that the cross-sectional area of the compressed air flow path 31 connecting the injector pipe 2 to the nozzle 3 is directed from the injector pipe 2 side to the tip side of the nozzle 3 as shown in FIG. In the present embodiment, as shown in FIG. 1 (b), the opening is formed so as to have a shape rising gradually around the opening hole.
Thereby, it is possible to provide the nozzle 3 which has a small loss and is excellent in function, more specifically, the nozzle 3 which can jet the compressed air in a rectified state.

  In order to evenly remove the sediment trapped on the surface of the filter cloth 1, when the nozzle 3 which is jetted in a state where the compressed air is rectified is used, the nozzle 3 and the opening of the filter cloth 1 are used. The distance H to the portion 11 is set to be about 0.5 to 2.5 times the diameter D of the opening 11 of the filter cloth 1, and preferably about 1.0 to 2.0 times.

  If the distance H is smaller than 0.5, which is the diameter D of the opening 11 of the filter cloth 1, the deposit on the upper part of the filter cloth 1 tends to remain without being wiped off. If it is larger than twice, the sediment at the lower part of the filter cloth 1 tends to remain without being wiped off.

When a plurality of nozzles 3 are provided in series on the injector pipe 2, the cross-sectional area of the compressed air flow path 31 connected from the injector pipe 2 to the nozzle 3 is set closer to the distal end than the nozzle 3 on the base end side of the injector pipe 2. Nozzles 3 are sequentially formed smaller.
As a result, variations in the amount of compressed air ejected from each of the plurality of nozzles 3 arranged in series with the injector pipe 2 (when the compressed air is supplied in a pulsed manner to the injector pipe 2 whose tip is closed, the injector Since the internal pressure (static pressure) of the pipe 2 rises from the distal end toward the proximal end, the amount of compressed air ejected from each of the nozzles 3 varies.) The sediment trapped on the surface of the filter cloth 1 corresponding to the nozzle 3 can be evenly removed.

The air supply unit 4 includes a branch pipe 41 for storing compressed air supplied from a compressor (not shown), and an insert-type pulse valve 42 mounted in the branch pipe 41. The stored compressed air is supplied to the injector pipe 2 connected to the pulse valve 42.
Thereby, the internal pressure loss of the pulse valve can be reduced, the response speed can be increased, and the sediment trapped on the surface of the filter cloth 1 can be evenly removed.

Here, a diaphragm valve shown in FIG. 2 is used as the pulse valve 42.
In this diaphragm valve, an opening 41b is formed in a housing of a branch pipe 41, a diaphragm 43 is attached to an outer surface of the housing so as to close the opening 41b, and a valve body 44 is provided in the diaphragm 43. I do. On the other hand, the injector pipe 2 is disposed such that the valve seat 2 a formed at the base end of the injector pipe 2 opens in the casing 41 c of the branch pipe 41.
As a result, the valve seat abutment surface 44a of the valve body 44 disposed on the diaphragm 43 and the valve seat 2a are arranged to face each other.

  Then, by displacing the valve body 44 via the diaphragm 43, the valve closing state (FIG. 2A) where the valve seat contact surface 44a of the valve body 44 and the valve seat 2a abut, and the valve body 44 By switching to the valve opening state (FIG. 2B) in which the gap flow path 44b is formed between the valve seat contact surface 44a and the valve seat 2a, the gap flow between the branch pipe 41 and the injector pipe 2 is changed. The sediment trapped on the surface of the filter cloth 1 is intermittently communicated by the passage 44b, and the sediment trapped on the surface of the filter cloth 1 is wiped off by the pressure gas ejected from the nozzle 3 provided on the injector pipe 2.

  In the diaphragm valve constituting the pulse valve 42, when the valve body 44 is in the open state, the valve seat contact surface 44a of the valve body 44 is the same as the inner surface 41a of the housing of the branch pipe 41 having the opening 41b. It is located in the plane or on the valve seat 2a side.

  The valve body 44 is moved by the displacement of the diaphragm 43, and the moving distance of the valve body 44 from the closed state to the open state is substantially constant depending on the size of the pulse valve 42.

  Therefore, when the valve body 44 is in the valve-open state, the valve seat abutment surface 44a of the valve body 44 is in the same plane as the inner surface 41a of the housing of the branch pipe 41 having the opening 41b or more than the valve seat. The means for positioning the valve body 44 on the side 2a is not particularly limited, but it is preferable to make the height dimension (movement direction dimension) of the valve body 44 large. .

  Although not shown, the outer surface of the branch pipe 41 is counterbored along the opening 41b of the branch pipe 41, and the entire pulse valve 42 is disposed close to the inner surface 41a of the branch pipe 41. When the valve body 44 is in the open state, the valve seat abutment surface 44a of the valve body 44 is in the same plane as the inner surface 41a of the casing of the branch pipe 41 having the opening 41b or is larger than the valve seat 2a. It may be located on the side.

  When the valve body 44 is in the valve-open state, the valve seat contact surface 44a of the valve body 44 is located closer to the valve seat 2a than the inner surface 41a of the housing of the branch pipe 41 having the opening 41b. When the compressed air in the branch pipe 41 flows toward the injector pipe 2, the contraction does not occur, but the compressed air hits the outer surface of the valve body 44, and the valve seat contact surface 44 a forms the branch having the opening 41 b formed therein. The supply efficiency of the compressed air is slightly lower than when the pipe 41 is located in the same plane as the inner surface 41a of the housing of the pipe 41. Therefore, when the valve body 44 is in the open state, the valve seat contact surface of the valve body 44 is opened. It is particularly preferable that 44a is located in the same plane as the inner surface 41a of the casing of the branch pipe 41 in which the opening 41b is formed.

  Thus, when the valve body 44 is in the valve-open state, the compressed air flow does not pass through the opening 41b formed in the casing of the branch pipe 41, so that the compressed air flow contracts. Therefore, the compressed air smoothly flows from the branch pipe 41 into the injector pipe 2 and the supply amount of the compressed air supplied to the injector pipe 2 does not decrease.

  When the diaphragm valve opens, a large amount of compressed air instantaneously flows into the injector pipe 2, and the compressed air is filtered from each of the plurality of nozzles 3 provided in series with the injector pipe 2. By spraying into the filter cloth 1 through the opening 11, the sediment trapped on the surface of the filter cloth 1 can be wiped off.

When the pulse valve 42 opens a bleed hole 43a at an appropriate position of the diaphragm 43 and closes the pulse valve 42, the compressed air in the branch pipe 41 is introduced into the valve chamber 46 through the bleed hole 43a. Thus, the pressure in the valve chamber 46 quickly becomes equal to the pressure in the casing 41c of the branch pipe 41.
By making the bleed hole 43a as small as possible, the opening operation of the pulse valve 42 can be accelerated.

  By the way, a neutralizing agent introduction unit (not shown) for supplying a neutralizing agent for attaching the neutralizing agent to the surface of the filter cloth 1 is provided in a pre-process in which the exhaust gas is introduced into the processing chamber 5 or when the exhaust gas is supplied to the processing chamber 5. At the position where the gas is introduced into the exhaust gas, a neutralizing agent such as slaked lime is added to the exhaust gas (or air during idle operation), and the exhaust gas (air) to which the neutralizing agent is added is introduced into the processing chamber 5 and filtered. By filtering with the cloth 1, a neutralizing agent can be attached to the surface of the filter cloth 1.

  In this dust collector, compressed air is provided directly to an opening 11 of a cylindrical filter cloth 1 from a nozzle 3 provided in an injector pipe 2, that is, to a opening 11 of the filter cloth 1 in a conventional general-purpose cleaning mechanism. Including the neutralizing reactant trapped on the surface of the filter cloth 1 by supplying in a pulsed manner without using the venturi tube 11A and without interposing an object in the opening 11 of the filter cloth 1 in an open state. By providing the air supply unit 4 for removing the sediment, the compressed air supplied in a pulsed manner from the nozzle 3 generates a pressure loss in the filter cloth 1 from the opening 11 of the filter cloth 1 in an open state. Since the pressure rise rate in the filter cloth 1 is maintained up to the tip of the filter cloth 1, for example, compressed air set at a relatively low pressure P (0.1 MPa <P <0.2 MPa) According to the table of filter cloth 1 It can be dropped equally pay captured deposits.

  The mechanism for removing the sediment trapped on the surface of the filter cloth 1 is schematically shown. In the case of a conventional dust collector, as shown in FIG. 1 is generally consumed in the upper part and the middle part, and the sediment deposited in the lower part cannot be removed. On the other hand, in the case of the dust collector of the present invention, as shown in FIG. The compressed air thus reached reaches the lower portion of the filter cloth 1, and the accumulated deposits can be evenly removed.

  By the way, the timing at which the sediment trapped on the surface of the filter cloth 1 is removed, that is, the timing at which the compressed air injection operation is performed, is based on a method in which timer operation is performed periodically and a method in which the differential pressure value of the filter cloth 1 is different. A method of sensing (as a trigger) that a preset differential pressure value has been reached is generally adopted.

  Among them, the method of performing regular operation by the timer operation has an advantage that the control of the injection operation of the compressed air can be easily performed, but when the concentration of the harmful gas component contained in the exhaust gas fluctuates, for example, When the concentration of the harmful gas component increases, the neutralization reaction tends to be incomplete.On the other hand, when the concentration of the harmful gas component decreases, the neutralizing agent is washed off in an unreacted state. However, there is a problem that the neutralizing agent is wasted.

  Further, the method of detecting (as a trigger) that the differential pressure value of the filter cloth 1 has reached a preset reference differential pressure value requires removing the sediment trapped on the surface of the filter cloth 1. On the other hand, when the concentration of the harmful gas component contained in the exhaust gas fluctuates, for example, when the concentration of the harmful gas component increases, the differential pressure value of the filter cloth 1 increases accordingly. There is a problem that the interval of the compressed air injection operation is shortened due to the increase of the gradient, and the operation efficiency of the dust collector is reduced. On the other hand, when the concentration of the harmful gas component is reduced, the differential pressure value of the filter cloth 1 is reduced. As a result, the interval between the operations of injecting the compressed air becomes extremely long due to the decrease in the rising gradient, and the neutralization reaction tends to be incomplete.

  Then, the control device for the compressed air injection operation sends a differential pressure value of the filter cloth 1 that triggers the compressed air injection operation to a preset harmful gas component based on the concentration of the harmful gas component contained in the exhaust gas. And a differential pressure value change setting means for changing and setting the reference differential pressure value in the range of the reference concentration and a differential pressure value different from the reference differential pressure value.

  Here, the concentration of the harmful gas component contained in the exhaust gas is determined by measuring the concentration of the harmful gas component contained in the exhaust gas before being introduced into the processing chamber 5 by a harmful gas component measurement device (not shown). Alternatively, the concentration of the harmful gas component contained in the exhaust gas after being processed in the processing chamber 5 may be measured.

  Then, as shown in FIG. 5, when the concentration of the harmful gas component contained in the exhaust gas is within the range of a preset reference concentration of the harmful gas component, as shown in FIG. The differential pressure value of the filter cloth 1, which triggers the injection operation, is set to a preset reference differential pressure value in the range of the reference concentration (in this embodiment, the reference differential pressure value is specifically 1.0 kpa. Although it is set, it can be set to an appropriate value according to the dust collector.)

When the concentration of the harmful gas component contained in the exhaust gas becomes higher than a predetermined reference concentration range of the harmful gas component, the differential pressure value of the filter cloth 1 which triggers the compressed air injection operation. Is set to a first differential pressure value higher than a preset reference differential pressure value in the range of the reference concentration (in the present embodiment, the first differential pressure value is specifically set to 1.2 kpa). However, it can be set to an appropriate value according to the dust collector.)
This suppresses the interval of the compressed air injection operation from being shortened due to the increase in the gradient of the differential pressure value of the filter cloth 1 caused by the increase in the concentration of the harmful gas component, thereby reducing the operating efficiency of the dust collector. An effect of improving, an effect of accelerating the neutralization reaction, an effect of reducing the amount of the neutralizing agent used and an effect of improving the durability of the filter cloth 1 can be obtained.

Here, when the concentration of the harmful gas component becomes higher than the range of the reference concentration, it is preferable not to change the amount of the neutralizing agent supplied to the surface of the filter cloth 1.
Thereby, the effect of further reducing the amount of the neutralizing agent used can be obtained.

On the other hand, when the concentration of the harmful gas component contained in the exhaust gas becomes lower than a preset reference concentration range of the harmful gas component, the differential pressure value of the filter cloth 1 which triggers the compressed air injection operation. Is set to a second differential pressure value lower than a preset reference differential pressure value in the range of the reference concentration (in this embodiment, the second differential pressure value is specifically set to 0.8 kpa. However, it can be set to an appropriate value according to the dust collector.)
This prevents the interval of the compressed air injection operation from becoming extremely long due to the decrease in the rising gradient of the differential pressure value of the filter cloth 1 caused by the decrease in the concentration of the harmful gas component, thereby preventing the neutralization reaction. A promoting effect and an energy saving effect can be obtained.

Here, when the concentration of the harmful gas component becomes lower than the range of the reference concentration, it is preferable to reduce the amount of the neutralizing agent supplied to the surface of the filter cloth 1.
Thereby, the effect of further reducing the amount of the neutralizing agent used can be obtained.

  Note that only one of the first differential pressure value and the second differential pressure value is set as a differential pressure value different from the reference differential pressure value set by the differential pressure value change setting means of the control device of the compressed air injection operation. It can also be done.

  As described above, the control device and the control method of the compressed air injection operation in the dust collector according to the present invention have been described based on the embodiments. However, the present invention is not limited to the configuration described in the above-described embodiments. The configuration can be appropriately changed without departing from the scope.

  ADVANTAGE OF THE INVENTION The control apparatus and control method of the injection operation of the compressed air in the dust collector of the present invention can use a relatively low-pressure compressed air to evenly remove the sediment and improve the operation efficiency of the dust collector. Exhaust gas discharged from various industrial equipment, especially because it has the property of obtaining the effect of promoting the sum reaction, the effect of reducing the amount of the neutralizing agent used, the effect of saving energy and the effect of improving the durability of the filter cloth The present invention can be suitably used for a dust collector for neutralizing exhaust gas discharged from a device involving combustion with a neutralizing agent.

DESCRIPTION OF SYMBOLS 1 Filter cloth 11 Opening 2 Injector pipe 3 Nozzle 4 Air supply part 41 Branch pipe 42 Pulse valve 5 Processing chamber

Claims (6)

Thereby removed from the flue gas by forming a neutralizing reactant harmful gas components are reacted with a neutralizing agent at the surface of the filtration cloth contained in the exhaust gas, by injecting compressed air into the opening of the filter cloth In a control device for a compressed air jetting operation in a dust collector configured to sweep off the neutralizing reactant present on a surface of the filter cloth, the control device includes: a differential pressure of a filter cloth which triggers a compressed air jetting operation. The value, based on the concentration of the harmful gas component contained in the exhaust gas, a reference differential pressure value when the range of the preset reference concentration of the harmful gas component, and the range of the preset reference concentration of the harmful gas component if it becomes higher than the control device of the injection operation of the compressed air in the dust collector, characterized in that it comprises a differential pressure value change setting means for setting into a first differential pressure have higher than the reference pressure value . By removing harmful gas components contained in the exhaust gas from the exhaust gas by reacting with a neutralizing agent on the surface of the filter cloth to form a neutralizing reactant, and injecting compressed air into the opening of the filter cloth In a control device for a compressed air jetting operation in a dust collector configured to sweep off the neutralizing reactant present on a surface of the filter cloth, the control device includes: a differential pressure of a filter cloth which triggers a compressed air jetting operation. The value, based on the concentration of the harmful gas component contained in the exhaust gas, a reference differential pressure value when the range of the preset reference concentration of the harmful gas component, and the range of the preset reference concentration of the harmful gas component if it becomes lower than the control device of the injection operation of the compressed air in the dust collector, characterized in that it comprises a differential pressure value change setting means for setting the second differential pressure value have lower than the reference pressure value .   By removing harmful gas components contained in the exhaust gas from the exhaust gas by reacting with a neutralizing agent on the surface of the filter cloth to form a neutralizing reactant, and injecting compressed air into the opening of the filter cloth In the method for controlling the operation of injecting compressed air in a dust collector so as to sweep off the neutralizing reactant present on the surface of the filter cloth, the concentration of the harmful gas component contained in the exhaust gas may be a predetermined harmful gas component. If it is higher than the reference concentration range, the differential pressure value of the filter cloth that triggers the compressed air injection operation is set higher than the preset reference differential pressure value in the reference concentration range. A method for controlling a compressed air injection operation in a dust collector.   4. The method according to claim 3, wherein when the concentration of the harmful gas component is higher than the reference concentration range, the amount of the neutralizing agent supplied to the surface of the filter cloth is not changed. 5. A method for controlling a compressed air injection operation in a dust collector.   By removing harmful gas components contained in the exhaust gas from the exhaust gas by reacting with a neutralizing agent on the surface of the filter cloth to form a neutralizing reactant, and injecting compressed air into the opening of the filter cloth In the method for controlling the operation of injecting compressed air in a dust collector so as to sweep off the neutralizing reactant present on the surface of the filter cloth, the concentration of the harmful gas component contained in the exhaust gas may be a predetermined harmful gas component. If it is lower than the reference concentration range, the differential pressure value of the filter cloth which triggers the compressed air injection operation is set lower than the preset reference differential pressure value in the reference concentration range. A method for controlling a compressed air injection operation in a dust collector.   6. The method according to claim 5, wherein when the concentration of the harmful gas component is lower than the range of the reference concentration, the amount of the neutralizing agent supplied to the surface of the filter cloth is reduced. A method for controlling a compressed air injection operation in a dust collector.

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