JP3297229B2 - Backwashing device for dust remover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backwashing device applied to a gas remover such as a gasifier or a pressurized fluidized bed combustion furnace.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional backwashing device for a dust remover. In FIG. 4, a cylindrical filter element 2 is built in a dust remover main body 1. The dust-containing gas 3 supplied from the pressurized fluidized bed combustion furnace (not shown) flows into the filter element 2, the dust is filtered on the inner surface of the filter element 2, and the pressure regulating valve 5 is supplied from the outlet pipe 4 connected to the outer surface. The gas is supplied to the gas turbine 6 via the gas turbine 6.

[0003] The dust adhering to the inner surface of the filter element 2 grows as the operation is continued and grows.
Since the pressure loss on the inner and outer surfaces increases, the differential pressure between the inner and outer surfaces is
Monitoring and periodically backwash the filter element 2
Dust removal.

[0004] The backwash line 8 is provided with a backwash nozzle 9 and a backwash valve 10 in the middle of the outlet pipe 4, and the backwash valve 10 is linked with the differential pressure gauge 7. That is, when the differential pressure of the filter element 2 increases, the backwash valve 10 is opened for about 0.3 to 0.5 seconds to generate a differential pressure in the reverse direction on the filter element 2 to remove dust. Since the dust that has been removed accumulates in the hopper at the lower portion of the main body 1, the dust is periodically discharged from the blowdown lines 14 a and 14 b to the outside of the dust remover 1.

[0005] The air source for backwashing is air from the compressor 11, which is depressurized by a pressure reducing valve 18 to adjust the pressure of the backwashing chamber 13 and then supplied as backwashing air.

[0006]

FIG. 5 shows a change with time of the filter element differential pressure during the operation of the dust remover provided with the above-mentioned backwashing device. Backwashing of filter element 2 is backwash valve 10
It is implemented by opening and closing. At the time of backwashing, compressed air is blown at a pressure of about three times the internal pressure (absolute pressure) of the filter element from the direction opposite to the gas flow at the time of dust removal to drop dust adhering to the inner surface of the filter element. In that case, the filter element differential pressure instantaneously swings to the minus side, causing a peak pressure loss during backwashing.

[0007] When the operation is settled (internal pressure and temperature settling), a result is obtained in which the backwash pressure is constant and the backwash peak pressure loss is stable. Even if it is constant, the viscosity and density of the backwash air change with temperature and are not constant, so that the peak pressure loss is not stabilized and the target peak pressure loss is not obtained.

[0008] Therefore, if the peak pressure loss is not obtained, the backwashing efficiency decreases, so that the backwashing time must be changed every time the backwashing is performed in order to obtain the desired backwashing effect. In order to avoid this, in the process of raising the temperature of the dust-containing gas, it is necessary to adjust the pressure reducing valve each time to set the backwash pressure.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dust-removing device for a dust-removing device having a filter element, in which the peak pressure loss during the back-flushing is kept constant and stable back-flushing is performed. .

[0010]

According to the present invention, in order to solve the above-mentioned problems, a pressure regulating valve is provided in place of a pressure reducing valve conventionally provided between a compressor and a backwashing chamber to freely control the pressure in the backwashing chamber. Control.

The backwashing device according to the present invention has a structure in which together with the pressure regulating valve, an internal temperature measuring means of the filter element and a control means for adjusting the pressure regulating valve based on the temperature measured by the internal temperature measuring means are provided. adopt. The pressure control of the pressure regulating valve is set in the control means in advance so that the pressure is adjusted according to the internal temperature of the filter element.

[0012]

The backwashing device for a dust remover according to the present invention employs the above-described structure. In the process of completing the pressure increase and increasing the internal temperature, each temperature of the filter element measured by the internal temperature measuring means is measured. The pressure control valve is controlled so as to give a backwash pressure according to the viscosity and density of the backwash gas in the above.

That is, for example, the control means is preset to change the backwash gas pressure in accordance with the internal temperature of the filter element as shown in FIG. 3 and automatically controls the pressure regulating valve. Thus, the peak pressure loss during backwashing is kept constant and stable backwashing is performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A backwashing device for a dust remover according to the present invention will be specifically described below with reference to an embodiment shown in FIG.
In the following embodiments, the same components as those of the conventional apparatus shown in FIG. 4 are denoted by the same reference numerals for the sake of simplicity. FIG. 1 is a system diagram of a backwashing device for a dust remover, similarly to FIG. The structure of the main body and the flow system of the dust-containing gas are the same as in the prior art shown in FIG.

In FIG. 1, a pressure regulating valve 12 for controlling the pressure in the backwash chamber 13 is provided between the compressor 11 and the backwash chamber 13. A thermocouple 15 is attached to the inner surface of the filter element 2 to detect the internal temperature of the filter element 2 and to detect the temperature of the computer 1.
7 can be instructed.

According to the temperature measured by the thermocouple 15, the computer 17 adjusts the pressure so that the backwash gas pressure (pressure gauge 16) considering the viscosity and density of the backwash gas is obtained in the backwash chamber 13 as shown in FIG. Control the valve 12. That is, while the internal temperature of the filter element 2 is low, a low backwash gas pressure is set, and as the temperature increases, the gas pressure also increases,
Thereafter, the gas pressure is also kept constant while being kept at the steady temperature.

Since the viscosity and density of the backwash gas decrease as the temperature increases, the backwashing operation efficiency deteriorates and the backwash gas pressure must be set high. As described above, according to the backwashing device for a dust remover shown in FIG. 1, stable backwashing is performed while maintaining a constant peak pressure loss during backwashing of the filter element.

[0018]

As described above in detail, according to the backwashing apparatus for a dust remover of the present invention, when backwashing is performed in the process of raising the temperature of the filter element, the backwash pressure is adjusted by the temperature. The peak pressure loss at the time of backwash can be adjusted to the target value. Therefore, a stable backwashing effect can be obtained even in the backwashing process as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a system diagram of a dust remover having a backwashing device for a dust remover according to an embodiment of the present invention.

FIG. 2 is a diagram showing a temporal change of a differential pressure in a filter element when backwashing is performed by the backwashing apparatus of the present invention.

FIG. 3 is a diagram showing a relationship between a filter element internal temperature and a backwash gas pressure.

FIG. 4 is a system diagram of a conventional dust remover provided with a backwashing device for a dust remover.

FIG. 5 is a diagram showing a change over time of a differential pressure in a filter element when backwashing is performed by a conventional backwashing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deduster main body 2 Filter element 3 Dust-containing gas 4 Outlet piping 5 Pressure control valve 6 Gas turbine 7 Differential pressure gauge 8 Backwash line 9 Backwash nozzle 10 Backwash valve 11 Compressor 12 Pressure control valve 13 Backwash chamber 14a, 14b Blowdown line 15 Thermocouple 16 Pressure gauge 17 Computer (control means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-223238 (JP, A) JP-A-6-294510 (JP, A) JP-A-57-30520 (JP, A) JP-A-6-294 190229 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 46/00-46/54

Claims (1)

(57) [Claims] A backwashing apparatus for a dust remover for intermittently supplying backwash air from a backwash chamber to a dust remover having a filter element to remove dust from the filter element.
A reverser for a dust remover, comprising: an internal temperature measuring means of the filter element, a pressure adjusting valve of the backwash chamber, and a control means for adjusting the pressure adjusting valve based on a temperature measured by the internal temperature measuring means. Washing equipment.