JPH0657289B2 - Operating method of filtration dust collection type exhaust gas treatment equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for treating combustion exhaust gas containing hydrogen chloride gas using a filter dust collecting type exhaust gas treatment apparatus equipped with a reverse air flow fan, and more specifically, , A new operating method for preventing clogging of a filter cloth with CaCl _{2 produced} by Tikatsu.

[Prior art and its problems] When a combustion exhaust gas containing HCl gas is treated using a filter dust collecting type exhaust gas treatment apparatus such as a bag filter,
Ca (OH) ₂ is added as a desalting agent to the exhaust gas on the upstream side. However, CaCl ₂ generated by the reaction between HCl and Ca (OH) ₂ exhibits remarkable deliquescent properties, especially at low temperatures, so that there is a problem that CaCl ₂ adheres to the filter cloth at low temperatures and causes clogging of the filter cloth. is there.

In view of the above situation, it is an object of the present invention to provide a method for preventing the deliquescent of CaCl ₂ from clogging the filter cloth, thereby operating the exhaust gas treatment device without any trouble.

[Means for Solving Problems] In order to achieve the above-mentioned object, a method for operating a filtration dust collection type exhaust gas treatment apparatus of the present invention uses a filtration dust collection type exhaust gas treatment apparatus equipped with a reverse air flow fan to remove hydrogen chloride gas. When treating the combustion exhaust gas containing it, the exhaust gas in the equipment is replaced with air by using the backflow fan when the operation of the treatment equipment is stopped or during preparation, and a heater is installed in the equipment to circulate the warm air by the heater. This is characterized by heating the filter cloth.

The temperature of the circulating hot air in the device is preferably maintained at 100 to 150 ° C. so that the deliquescent of CaCl ₂ is effectively prevented.

Air replacement of exhaust gas and circulation of warm air in the device
Preferably, the dust collection processing direction of the flow direction of the circulating warm air in a part of the plurality of rooms in the device is left as it is, and the flow direction of the circulating warm air in the remaining rooms is set to the dust collection processing direction. Instead of the reverse direction, the induction fan is stopped and the reverse airflow fan is operated. Also, the opening and closing of a damper that changes the flow direction of the circulating hot air is controlled by a timer or by detecting pressure loss or the like. In this way, the heating of the filter cloth and the dust adhering to the filter cloth are uniformly removed in all the rooms.

[Operation] In the operating method according to the present invention, when the exhaust gas treatment device is stopped or is prepared, the exhaust gas in the device is replaced with air by using the reverse air flow fan, and a heater is installed in the device to control the temperature by the heater. Since the air is circulated, the filter cloth is heated by the circulating hot air, and as a result, the deliquescent of CaCl ₂ is prevented and the filter cloth is not clogged.

[Examples] Next, the present invention will be described in detail with reference to the illustrated examples.

In the attached drawings, the bag filter body (1) is divided into four chambers (2), (3), (4) and (5), and a filter cloth (12) is stretched in each corner chamber. Also, each room (2) (3) (4) (5)
Process gas passages (2a) (3a) (4a) (5a) and reverse air flow passages (2b) (3b) (4b) (5b) are provided at the top of each. The process gas passages (2a) (3a) (4a) (5a) each have a dust collecting damper (6).
And a reverse airflow damper (7) is attached to each of the reverse airflow passages (2b), (3b), (4b), and (5b). Then, the processing gas passages (2a) (3a) (4a) (5a) are connected to the inlet end branch portion (8a) of the processing gas conduit (8), respectively, and
(2b), (3b), (4b), and (5b) are connected to the inlet end branch portion (9a) of the reverse airflow conduit (9), respectively. The processing gas conduit (8) is provided with an induction fan (10) for drawing the processing gas from the processing gas passage. Further, the reverse airflow conduit (9) is provided with a reverse airflow fan (11) that sends an airflow to the reverse airflow passage in order to scavenge the dust adhering to the filter cloth (12). The process gas conduit (8) is also connected to the inlet side of the backflow fan (11). In each room (2) (3) (4) (5), a heater is provided on the downstream side of the filter cloth (12) and below the reverse airflow passages (2b) (3b) (4b) (5b).
(13) is provided.

In the bag filter with the above configuration, during normal dust collection operation, all dust collection dampers (6) are opened and all reverse airflow dampers (7) are closed to stop and attract the reverse airflow fan (11). By operating the fan (10), dust collection processing of exhaust gas is performed.

Also, when the bag filter is stopped or prepared,
The direction of gas flow in the room (2) and the room (4) among the rooms (2), (3), (4) and (5) is maintained as the dust collection processing direction, and the room (3) and the room (5) are maintained. The flow direction of is changed to the opposite direction of the dust collection processing direction. That is, dampers for dust collection in room (2) and room (4)
(6) is opened as it is, and both the dust collecting dampers (6) of the room (3) and the room (5) are closed, and the reverse air flow dampers ((2) and (4)) 7) Keep it closed,
At the same time, open the backflow dampers (7) in the room (3) and room (5). Then, the attraction fan (10) is stopped and the reverse airflow fan (11) is operated. As a result, the exhaust gas in the bag filter main body (1) is replaced with air and the heater (1
The hot air having a temperature of 100 to 150 ° C. generated by 3) is circulated in the bag filter body (1). Thus, the circulating warm air heats the filter cloth (12), and CaC
The deliquescent of l ₂ is prevented, and the risk of clogging of the filter cloth is eliminated.

Next, the open / closed state of each dust collecting damper (6) and reverse airflow damper (7) is reversed to the above state, and the flow direction of the circulating hot air in the room (2) and the room (4) is changed to the reverse flow direction. , And the room
The flow direction of circulating hot air in (3) and the room (5) is changed to the dust collection processing direction. The opening / closing of the dampers 6 and 7 is controlled by a timer or by detecting pressure loss or the like. In this way, the heating of the filter cloth (12) and the dust adhering to the filter cloth (12) are uniformly removed in all the rooms (2) (3) (4) (5).

[Advantages of the Invention] In the operating method according to the present invention, the exhaust gas in the device is replaced with air by using the reverse airflow fan when the exhaust gas treatment device is stopped or prepared, and the heater is installed in the device. since circulating hot air, circulating hot air the filter cloth is allowed to warm by to prevent the the result of CaCl ₂ deliquescence arises, reliably prevent the filter cloth by deliquescence of CaCl ₂ is causing clogging Therefore, the exhaust gas treatment device can be operated without any trouble.

[Brief description of drawings]

The drawing is a cutaway front view of a bag filter showing an embodiment of the present invention. (1) …… Bug filter body, (2) (3) (4) (5) …… Room, (6)
…… Dust collection damper, (7) …… Backflow air damper, (8) …… Process gas conduit, (9) …… Backflow air conduit, (10) …… Induction fan, (11) …… Backflow air Fan, (12) …… filter cloth, (13) …… heater.

Claims (1)

[Claims] 1. When treating a combustion exhaust gas containing hydrogen chloride gas by using a filter dust collecting type exhaust gas treatment apparatus equipped with a reverse air flow fan, the reverse air flow fan is utilized at the time of shutdown or preparation of the treatment apparatus. A method for operating a filter dust collecting type exhaust gas treatment apparatus, characterized in that the exhaust gas in the apparatus is replaced with air, and a heater is installed in the apparatus and warm air is circulated by the heater to heat the filter cloth. .