JPH0341769Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to bag filters, and is an improvement in the opening/closing structure of each damper that allows clean gas to flow into the discharge side and backwash air to flow into the filtration chamber. Regarding.

[Background technology and its problems]

Traditionally, boilers have been widely used in chemical factories, various machinery factories, etc., but since the exhaust gas from these boilers contains many ducts,
A filter is used to remove dust from the exhaust gas exhaust path. This type of filter has mechanical,
There are various types of filters that electrically remove dust, but among these, bug filters are widely used because they are relatively easy to maintain and inspect.

4 and 5 show the components of a conventional bug filter. The filtration chambers in these figures are actually multiple filters arranged in tandem in the horizontal direction to constitute the entire bag filter, but in order to avoid complication in the drawings, only one filtration chamber is shown and the other filtration chambers are not shown. is omitted.

In FIGS. 4 and 5, a filtration chamber 1 is formed in a substantially cylindrical shape, and a hopper 3 is provided in the lower part of the filtration chamber 1 with a partition wall 2 in between. A hole 4 is bored in a part of the partition wall 2, and the filtration chamber 1 and the hopper 3 are communicated through the hole 4.

A pipe 5 connected to an exhaust pipe of a boiler (not shown) is connected to the side wall of the hopper 3, and exhaust gas from the boiler flows into the hopper 3 through the pipe 5.

A filtration bag 6 constituted by a long bottomed bag made of cloth or paper is disposed in the filtration chamber 1, and the opening side of the bag 6 is perforated in the partition wall 2. It is connected to the hole 4 by an appropriate means, and its bottom side is suspended from a transverse member 7 that extends over the top of the filtration chamber 1, and exhaust gas flows into this bag 6 via the hopper 3. It's becoming like that. In addition, the bug 6 is
A plurality of filters are provided in the filtration chamber 1, and each opening side is connected to a hole 4 formed in the partition wall 2, and the bottom side is suspended from the transverse member 7.

At the upper end of the filtration chamber 1 is a chamber 11 connected to an exhaust duct 8 for discharging clean gas and a backwash duct 10 for supplying air for backwashing the bugs 6.
is defined.

A communication hole 15 for circulating clean gas to the duct 8 side is formed at the bottom of the chamber 11, and a valve seat 15A is formed at the periphery of the communication hole 15 on the clean gas discharge side, and An air cylinder 16 is provided above it. This air cylinder 16 includes a cylinder 17 and this cylinder 1.
7 and a piston rod 19 fixed to the piston 18, and a main damper 20 is attached to the tip of the piston rod 19. The cylinder 16 is driven to move forward and backward relative to the valve seat 15A, thereby opening and closing the communication hole 15.

A communication hole 22 for circulating backwashing air into the filter chamber 1 is formed at a position adjacent to the communication hole 15 at the bottom of the chamber 11, and a valve is provided at the periphery of the communication hole 22. A seat 22A is provided, and an air cylinder 23 is provided above the seat 22A. Like the air cylinder 16, this air cylinder 23 includes a cylinder 24, a piston 25, and a piston rod 26. At the tip of the piston rod 26, there is a backwash damper 2 that can move forward and backward with respect to the valve seat 22A.
7 is attached, and the communication hole 22 is opened and closed by this backwash damper 27.

When discharging clean gas in the conventional bag filter configured as described above, the main damper 20 on the clean gas discharge side is set to the open position and the communication hole 15 is opened, while the main damper 20 on the clean gas discharge side is set to the open position and the communication hole 15 is opened. The backwash damper 27 is set to the closed position and the communication hole 22 is blocked, and in this state, the exhaust gas from the boiler is removed by the bag 6, and the clean air after dust removal is discharged through the communication hole 15 and the duct 8. be done.

On the other hand, when backwashing is performed to remove dust attached to the bug 6, contrary to the above, the communication hole 15 on the clean gas discharge side is closed, and the communication hole 22 on the backwash air supply side is opened. In this state, air is supplied from an air supply device (not shown) into the filtration chamber 1 through the duct 10 and the communication hole 22, thereby causing the bag 6 to flap, shaking off the dust adhering to the bag 6, and causing it to enter the hopper 3. Supplementary information.

Although such conventional bag filters achieve dust removal and backwashing with a simple configuration, they have the following drawbacks.

That is, the entire bag filter is quite large, and the diameter and wall thickness of each damper 20, 27 are also formed considerably large.
As a result of the large weight of the main damper 7 itself, when a situation occurs in which the pressure of the operating air given to the air cylinder 16 fluctuates when discharging clean gas, the main damper 20 descends due to its own weight and closes the communication hole 15. The boiler's exhaust route will be blocked at this point, and the boiler will have to stop operating.

This problem is not just a problem with the boiler, but also often requires the operation of related equipment to be stopped, and is a problem that cannot be ignored, especially in factories, as it reduces the overall operating rate.

[Purpose of invention]

An object of the present invention is to provide a bag filter that does not block the discharge path due to the weight of the damper itself even if the operating pressure of the air cylinder fluctuates, thereby avoiding a decrease in the operating rate.

[Means and actions for solving problems]

Therefore, in the present invention, a filtration bag is provided in the filtration chamber, and a discharge duct for discharging clean gas and a backwash duct for supplying air for backwashing the bag are provided adjacent to the filtration chamber. A main damper that opens and closes a communication hole between the filtration chamber and the discharge duct to allow clean gas to flow into the discharge side, and a main damper that opens and closes the communication hole between the filtration chamber and the backwash duct to allow backwash air to flow into the filtration chamber. In the bag filter, the main damper is provided below the valve seat on which the main damper is seated, and the backwash damper is configured to be driven by an air cylinder. It is characterized by being provided above the valve seat on which the washing damper is seated.

In other words, the present invention focuses on the fact that the boiler exhaust path is blocked due to the main damper's own weight and the operating pressure fluctuation of the air cylinder, and the exhaust path is blocked even if the main damper falls due to its own weight. This prevents unnecessary stoppage of the boiler, and also prevents the backwash air inflow path from being opened even if the backwash damper falls due to its own weight. This objective is achieved by preventing the flow of clean gas from being obstructed by the inflow of backwashing air.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Note that the same reference numerals are used for the same or substantially equivalent components as in the conventional example, and the description thereof will be omitted or simplified. Also,
The filtration chamber is similar to that shown in the conventional configuration,
One example will be illustrated and explained based on this.

1 and 2, a backwash duct 10 for supplying air for backwashing is connected to an air cylinder 16,
It is located between 23.

Further, the valve seat 15A on the side of the communication hole 15 for sending clean air to the exhaust duct 8 is provided below the periphery of the communication hole 15, and the main damper 20 that opens and closes the communication hole 15 is connected to the valve seat 15A. Lower side than 15A,
That is, the main damper 20 is provided on the side opposite to the discharge of clean air, thereby preventing the main damper 20 from blocking the communication hole 15 due to its own weight.

On the other hand, the valve seat 22A on the communication hole 22 side for sending backwash air to the filtration chamber 1 is provided above the periphery of the communication hole 22, and the backwash damper 27 that opens and closes the communication hole 22 is The backwash damper 27 is provided above the valve seat 22A, thereby preventing the backwash damper 27 from opening the communication hole 22 due to its own weight.

Next, a system for driving the air cylinders 16 and 23 will be explained with reference to FIG. In addition,
The drive system shown in FIG. 3 mainly shows an air cylinder 16 that drives a main damper 20 that allows clean air to flow into the exhaust side, and the other air cylinder 23 is partially omitted, but both air cylinders 16 and 23 are partially omitted. The cylinders 16 and 23 are driven on the same principle.

In FIG. 3, passages 31 and 32 are formed in the portions of the cylinder 17 above the upper limit position and below the lower limit position of the piston 18, respectively;
One ends of air pipes 34 and 35 are connected to these passages 31 and 32. These air pipes 34,
The other end of 35 is, for example, a 4-port 2-position solenoid valve 3.
6, respectively. This solenoid valve 36
is configured to switch the port position of the electromagnetic valve 36 in response to an electric signal given from the sequence control device 37 and alternately supply operating air to the air pipes 34 and 35, whereby the piston 18 is raised and lowered, The communication hole 15 is opened and closed by raising and lowering the main damper 20 attached to the piston rod 19.

A solenoid valve 38 provided separately from the solenoid valve 36 is connected to the sequence control device 37, and an air pipe 40 connected to the solenoid valve 38,
41 is connected to an unillustrated upper and lower passage of the other cylinder 24.

Note that a scale portion 43 is provided on the lower peripheral wall portion of the cylinder 17 along the axial direction of the cylinder 17, and a pointer 44 is provided on the piston rod 19.
is fixed, and by visually checking the position of the pointer 44 with respect to the scale portion 43, it is possible to confirm whether the main damper 20 is open or closed.

Next, the operation of the bug filter in this embodiment will be explained.

In the process of removing dust from exhaust gas from the boiler,
An electric signal given to the solenoid valve 36 by the sequence control device 37 causes the solenoid valve 36 to close the air pipe 34.
Switch the port to a position where operating air can be supplied to.

The air supplied into the cylinder 17 from the air pipe 34 pushes down the piston 18 and the piston rod 19, which causes the main damper 20
is lowered to the open position and the communication hole 15 is opened.

In this state, the exhaust gas from the boiler is
The clean air that flows into the bag 6 through the hole 4 of the partition wall 2 and is dust-removed by the bag 6 is discharged from the duct 8 through the communication hole 15. At this time, the sequence control device 37 controls the backwash damper 2
7 closes the communication hole 22.
The solenoid valve 38 that is to supply operating air to the air is controlled.

When the clean gas is discharged for a predetermined period of time and the bag 6 is backwashed, the sequence control device 37
gives an electric signal to each electromagnetic valve 36, 38 so that the open/close state of the dampers 20, 27 is reversed from the above,
As a result, the main damper 20 on the clean gas discharge side is placed in the closed position and closes the communication hole 15, while the other backwash damper 27 is placed in the open position and closes the communication hole 22.
is opened, and in this state, operating air supplied from the backwash duct 10 provided between the air cylinders 16 and 23 is supplied into the filtration chamber 1 through the communication hole 22, causing the bag 6 to flap and removing the bag. The dust adhering to the inside of the hopper 6 is shaken off, and this dust is collected inside the hopper 3.

According to this embodiment as described above, there are the following effects.

That is, in conventional bag filters, the main damper that allows clean gas to flow into the discharge side duct is provided on the clean gas discharge side, that is, above the valve seat. seat 1
Since the main damper 20 is provided on the lower side of 5A, that is, on the side opposite to the discharge of clean gas, even if the operating pressure supplied to the air pipe 34 decreases when discharging clean gas, the damper There is no blockage of the communication hole 15 due to the dead weight of the boiler 20, which eliminates the conventional problem of stopping the operation of the boiler and related equipment, thereby avoiding a decrease in the operating rate of the entire factory, etc. can.

In addition, since the backwash damper 27 is provided above the valve seat 22A, even if the operating pressure supplied to the air pipe 40 during discharge of clean gas decreases, the damper 27's own weight will reliably close the communication hole 22. Because you can
Backwash air, atmosphere, etc. do not flow in from the backwash duct 10. Therefore, the flow of exhaust gas is not obstructed by backwashing air, etc., and the suction blower used to discharge clean gas becomes overloaded and has to be stopped due to poor gas flow. This eliminates the possibility of this happening, thereby increasing safety and preventing a decrease in the operating rate.

That is, according to this embodiment, the main damper 20 that opens and closes the communication hole 15, which should be always open during normal operation, is provided below the valve seat 15A, while the main damper 20 is opened only during backwashing and should be always closed during normal operation. By providing the backwash damper 27 that opens and closes the communication hole 22 above the valve seat 22A, each damper 20,
Even if the air pressure of the air cylinders 16 and 23 that move the air cylinders 27 fluctuate, the normal operating state can be maintained, and a decrease in the operating rate can be avoided.

In addition, when installing the main damper 20 below the valve seat 15A, it can be easily handled by changing the operation air supply cycle to the air pipes 34 and 35, but there is a problem in that equipment costs rise compared to conventional devices. Nor.

[Effect of idea]

According to the present invention as described above, even if the operating pressure of the air cylinder fluctuates, the dead weight of the damper does not block the clean air discharge path, thereby providing a bug filter that can avoid a decrease in the operating rate. There is an effect that it can be done.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the clean gas discharge state of the bag filter according to the present invention, FIG. 2 is a front view showing the same backwash state, and FIG. 3 is a schematic configuration diagram of the system for driving the air cylinder. Figures 4 and 5
The figures are front views of a conventional bag filter, with FIG. 4 showing a clean gas discharge state and FIG. 5 showing a backwashing state. 1...filtration chamber, 3...hopper, 6...bug, 8
...Discharge duct, 10...Backwash duct, 15,2
2...Communication hole, 15A, 22A...Valve seat, 16...
...Air cylinder, 20...Main damper, 27...Backwash damper.

Claims (1)

[Scope of utility model registration request] A filtration bag is installed in the filtration chamber, and
A discharge duct for discharging clean gas and a backwash duct for supplying air for backwashing bugs are provided adjacent to the filtration chamber, and a communication hole between the filtration chamber and the discharge duct is opened and closed to discharge the clean gas. A main damper that allows air to flow into the filtration chamber, and a backwash damper that opens and closes a communication hole between the filtration chamber and the backwash duct to allow backwash air to flow into the filtration chamber are driven by an air cylinder. In the configured bag filter, the main damper is provided below the valve seat on which the main damper is seated,
A bag filter characterized in that the backwash damper is provided above a valve seat on which the backwash damper is seated.