JP3252092B2 - Bag filter type dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag filter type dust collecting apparatus for removing exhaust gas generated from, for example, a waste incinerator.

[0002]

2. Description of the Related Art For example, in a waste incineration plant, FIG.
As shown in the schematic system diagram in FIG. 1, in a refuse incinerator 1, exhaust gas generated at the time of refuse incineration is heat-exchanged from a refuse incinerator 1 by a heat exchanger 2 including a gas air heater for recovering residual heat, and then cooled. Slaked lime for adding the concentration of harmful gas therein to a specified value or less is added, sent to a bag filter type dust collector 3, dust-removed by a plurality of cylindrical filter cloths 4 attached to the dust collector 3, and passed through a flue 5 to a chimney 6 to the atmosphere. Reference numeral 7 denotes an exhaust gas suction fan provided in the middle of the flue 5.

When the exhaust gas is removed by the bag filter type dust collector 3, the temperature of the exhaust gas at the start of incineration in the refuse incinerator 1, that is, at the time of starting the furnace, is about 2 μm.
It is low around 0 ° C. When such low-temperature exhaust gas is sent to the bag filter type dust collector 3, dust moistened by moisture in the gas adheres to the filter cloth 4 of the dust collector 3 to cause clogging, so that the dust collecting function of the filter cloth 4 is deteriorated. Problems arise.

On the other hand, the temperature of the exhaust gas at the end of the incineration of the refuse incinerator 1 in which the fire is left, that is, at the time of igniting, is as high as 300 ° C. or more. When such high-temperature exhaust gas is sent to the bag filter type dust collector 3, there is a problem that the filter cloth 4 of the dust collector 3 is burned.

Therefore, in order to prevent the above-mentioned problem,
Conventionally, a branch duct 9 branching from the duct 8 and directly leading to the flue 5 without passing through the dust collector 3 is provided at the inlet duct 8 of the bag filter type dust collector 3 so that the waste incinerator 1 The exhaust gas discharged from is discharged directly into the atmosphere via the branch duct 9 without removing dust.

Further, in order to remove dust and the like attached to the outer surface of the gas air heater of the heat exchanger 2 for recovering residual heat, it is necessary to clean the outer surface of the gas air heater by jetting air as needed. Since the exhaust gas for cleaning has a low temperature, as described above, dust in the exhaust gas adheres to the filter cloth 4 of the dust collector 3 and causes clogging. Therefore, the exhaust gas does not pass through the dust collector 3 but directly passes through the branch duct 9 to the chimney. From 6 release to the atmosphere.

[0007]

As described above, exhaust gas containing dust discharged from a refuse incinerator or exhaust gas for cleaning a gas air heater is removed by a bag filter type dust collector at the time of starting up the furnace and igniting. If it is released into the atmosphere without it, it will pollute the air and cause pollution problems.

[0008] Accordingly, an object of the present invention is to solve the above-mentioned problems, and a pollution problem arises when exhaust gas containing dust discharged from a refuse incinerator or exhaust gas for cleaning a heat exchanger is discharged at the time of furnace startup and igniting. It is another object of the present invention to provide a bag filter type dust collecting apparatus capable of removing dust without lowering its function due to clogging and burning of a filter cloth of the bag filter type dust collector.

[0009]

According to the present invention, there is provided a clean room having a plurality of filter cloths attached to a lower surface for removing dust in exhaust gas discharged from an incinerator and subjected to heat exchange in a heat exchanger. A filter cloth chamber at the lower part of the cleaning chamber, an inlet duct for blowing dust-containing exhaust gas is connected to a lower part of the filter cloth chamber, and an exhaust duct for exhausting the dust-removed exhaust gas to the cleaning chamber. In a bag filter type dust collecting apparatus connected to an outlet duct provided with a suction fan in the middle thereof, the cleaning chamber is provided with a filter cloth for removing exhaust gas during a steady operation of the incinerator. A partition and a second cleaning chamber to which a filter cloth for removing exhaust gas during startup and incineration of the incinerator or exhaust gas for cleaning the heat exchanger and removing exhaust gas during steady-state operation are attached. Partitioned by The first clean room is connected to the outlet duct, the second clean room is connected to a second duct leading to the outlet duct, and the inlet duct is connected to the second clean room. And a temperature adjusting air supply duct for supplying air at a predetermined temperature for adjusting the temperature of the exhaust gas sent to the air conditioner.

[0010] A temperature controller is provided in the middle of the temperature control air supply duct, and controls the temperature of the exhaust gas when the incinerator is started and ignited and the exhaust gas for heat exchanger cleaning. It is adjusted by air of a predetermined temperature from the air supply duct.

[0011]

FIG. 1 is a schematic system diagram showing one embodiment of the apparatus of the present invention. As shown in the drawing, in the apparatus of the present invention, a cleaning chamber 10 having a plurality of cylindrical filter cloths 4 attached to the lower surface, and a filter cloth chamber 11 below the cleaning chamber 10.
The clean room 10 in the bag filter type dust collector 3 comprising: a first clean room 10a in which a filter cloth 4 for removing dust-containing exhaust gas during normal operation is installed; and an exhaust gas during startup and incineration of an incinerator. Alternatively, a filter cloth 4 'for removing the exhaust gas for cleaning the heat exchanger and removing the exhaust gas during a steady operation.
Is partitioned by a partition wall 12 into a second cleaning room 10b to which the. The first clean room 10a has an area capable of removing the exhaust gas during a steady operation by the filter cloth 4 attached to the first clean room 10a.
The area of Ob is about 20% of the area of the first clean room 10a.

An outlet duct 13 leading to the flue 5 is connected to the first clean room 10a, and a second outlet duct 14 connected to the outlet duct 13 is connected to the second clean room 10b. A first damper 15 is provided on the outlet duct 13 upstream of a connection portion of the second outlet duct 14, and a second damper 16 is provided on the way of the second outlet duct 14.

An inlet duct 8 for blowing dust-containing exhaust gas is connected to a lower portion of the filter cloth chamber 11, and the inlet duct 8 has a predetermined temperature for adjusting the temperature of the dust-containing exhaust gas flowing therein. A temperature regulating air supply duct 17 for supplying air is connected. A blower 18 is provided in the temperature-controlled air supply duct 17, and a heater 19 and a third damper 20 as a temperature controller are provided in the duct 17. 21 is the entrance duct 9
, A blower 18, a heater 19, and a third damper 2 by a control circuit of the temperature sensor.
The operation of 0 is automatically controlled.

Next, the operation of the device of the present invention will be described. When starting up the incinerator, the first damper 15 of the outlet duct 13 is closed, and the second damper 16 of the second duct 14 is closed.
And third damper 20 of temperature-controlled air supply duct 17
Open. Then, the exhaust gas containing dust having a low temperature of about 20 ° C., which is sent into the filter cloth chamber 11 of the dust collector 3 from the inlet duct 8, is heated to about 100 ° C. by the heater 19 from the duct 17 for supplying temperature-regulated air. The air for heating is blown by the blower 18 to raise the temperature of the low-temperature dust-containing exhaust gas flowing in the inlet duct 8 to about 80 ° C.

The dust-containing exhaust gas that has been heated in this manner and blown into the filter cloth chamber 11 is opened by the second damper 16 provided in the second duct 14 connected to the second cleaning chamber 10b. As a result, the air is sucked by the second duct 14, the dust is removed only by the filter cloth 4 ′ attached to the lower surface of the second cleaning chamber 10 b, and the dust passes from the flue 5 through the second duct 14 and the outlet duct 13. It is discharged to the chimney 6.

Since the temperature of the exhaust gas for cleaning the heat exchanger is also low, the temperature of the exhaust gas is raised by the heated air blown from the temperature-controlling air supply duct 17 and the second duct 14 sucks the air. The dust is removed only by the filter cloth 4 'attached to the lower surface of the second clean room 10b.
Through the second duct 14 and the outlet duct 13, the flue 5
From the chimney 6.

On the other hand, when the incinerator is ignited, the exhaust gas containing dust having a temperature of 300 ° C. or more and sent into the filter cloth chamber 11 of the dust collector 3 is cooled from the temperature-controlled air supply duct 17 at room temperature. Air for use is blown by the blower 18 to lower the temperature of the dust-containing exhaust gas of 300 ° C. or higher flowing in the inlet duct 8 to about 200 ° C. or lower.

The dust-containing exhaust gas thus cooled and sent into the filter cloth chamber 11 is subjected to dust removal only by the filter cloth 4 'attached to the lower surface of the second cleaning chamber 10b in the same manner as described above. The air is discharged from the stack 5 to the chimney 6 through the second duct 14 and the outlet duct 18.

During the steady operation of the incinerator, the first damper 15 of the outlet duct 13 is opened, the second damper 16 of the second duct 14 is opened, and the temperature regulating air supply duct 17 is opened.
Of the third damper 20 is closed. As a result, the exhaust gas containing ducts at a temperature of about 200 ° C. or less discharged from the incinerator,
The filter cloth 4 sent from the inlet duct 8 into the filter cloth chamber 11 of the dust collector 3 and attached to the lower surface of the first cleaning chamber 10a and the filter cloth 4 'attached to the lower surface of the second cleaning chamber 10b.
Through the outlet duct 13 and the second duct 1
The air is discharged from a stack 5 to a chimney 6 through a stack 4.

Since the present invention is configured as described above, the dust-containing exhaust gas when the incinerator is started up and ignited is also discharged by the dust collector 3 into the atmosphere after being removed. Therefore, there is no possibility of polluting the air and causing a pollution problem.

The low-temperature exhaust gas generated when the incinerator is started is heated to about 80 ° C. or more by the heating air from the temperature-controlling air supply duct 17, and then the filter cloth chamber 11 is heated.
And the dust is removed by the filter cloth 4 'attached to the lower surface of the second cleaning chamber 10b, so that the dust rarely adheres to the filter cloth 4' and causes clogging. Even when clogging occurs, Since only the filter cloth 4 'in the second clean room 10b needs to be replaced, it is economical and the replacement work is easy.

The high-temperature exhaust gas generated at the time of incineration of the incinerator is cooled to about 200 ° C. or less by cooling air from a temperature-controlling air supply duct 17 and sent to the filter cloth chamber 11. (2) Since dust is removed by the filter cloth 4 'attached to the lower surface of the clean room 10b, the filter cloth 4' is hardly burned.
It is economical because only the filter cloth 4 'in the portion 0b needs to be replaced, and the replacement work is also easy.

The above-described opening and closing of the dampers 15, 16 and 20 during startup, incineration and steady operation of the incinerator, the exhaust gas suction fan 7 provided in the flue 5 and the supply of temperature-regulated air The operation of the blower 18 and the heater 19 provided in the duct 17 are all performed by the temperature sensor 2.
The control is automatically performed by the control circuit 1 and the functional control according to the state of the incinerator of the dust collector 3 is performed.

[0024]

As described above, according to the apparatus of the present invention, in a bag filter type dust collector for collecting dust-containing exhaust gas generated in a refuse incinerator or the like, at the time of furnace startup and igniting. Occasionally, dust-containing exhaust gas discharged from an incinerator or exhaust gas for cleaning a heat exchanger does not cause pollution problems, and the temperature of the exhaust gas is automatically and appropriately controlled to prevent the filter cloth of the dust collector from clogging. An industrially useful effect that can remove and discharge dust with high performance without causing burning is brought about.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram showing one embodiment of a dust collecting device of the present invention.

FIG. 2 is a schematic system diagram of a conventional dust collector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Garbage incinerator 2 Heat exchanger 3 Bag filter type dust collector 4, 4 'filter cloth 5 Chimney 6 Chimney 7 Exhaust gas suction fan 8 Inlet duct 9 Branch duct 10 Clean room 10a 1st clean room 10b 2nd clean room 11 filter Cloth room 12 Partition wall 13 Outlet duct 14 Second duct 15 First damper 16 Second damper 17 Duct for air supply for temperature adjustment 18 Blower 19 Heater 20 Third damper 21 Temperature sensor

Continuation of front page (72) Inventor Naoichi Kishi 61-1, Ono-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside NK Plant Construction Co., Ltd. (56) References JP-A-3-26313 (JP, A) JP-A-3-3- 87511 (JP, A) JP-A-4-141209 (JP, A) JP-A-6-79118 (JP, A) JP-A 8-266834 (JP, A) JP-A-5-76515 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 46/00-46/54

Claims (2)

(57) [Claims] 1. A clean room having a plurality of filter cloths attached to a lower surface thereof for removing dust in exhaust gas discharged from an incinerator and subjected to heat exchange in a heat exchanger, and a filter cloth at a lower part of the clean room. An inlet duct for blowing dust-containing exhaust gas is connected to the lower part of the filter cloth chamber, and the exhaust gas after dust removal is discharged to the clean room.
In a bag filter type dust collecting apparatus to which an outlet duct provided with a suction fan is connected in the middle thereof, the cleaning chamber is a first cleaning chamber to which a filter cloth for removing exhaust gas during steady operation of an incinerator is attached. And a second cleaning chamber to which a filter cloth for removing exhaust gas during startup and incineration of the incinerator or exhaust gas for purifying the heat exchanger and removing exhaust gas during steady-state operation is attached. The outlet duct is connected to the first clean room,
A second duct leading to the outlet duct is connected to the second clean room, and air at a predetermined temperature for adjusting the temperature of exhaust gas sent to the second clean room is supplied to the inlet duct. A bag filter type dust collecting device, wherein a duct for supplying temperature-regulated air is connected. 2. A temperature regulator is provided in the middle of the temperature-regulated air supply duct, and controls the temperature of the exhaust gas and the exhaust gas for heat exchanger cleaning when the incinerator is started and ignited. The dust collector according to claim 1, wherein the dust is adjusted by air at a predetermined temperature from a temperature-adjusting air supply duct.