EP0925838B1

EP0925838B1 - A method for cleaning a static precipitator and a device thereof

Info

Publication number: EP0925838B1
Application number: EP98123933A
Authority: EP
Inventors: Mei-Ling Huang
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-23
Filing date: 1998-12-16
Publication date: 2003-04-16
Anticipated expiration: 2018-12-16
Also published as: ZA9811753B; EP0925838A1; CN1220918A; CA2256220A1; CN1137001C; SG73589A1; MY132968A; NZ332848A; DE69813485D1; ATE237405T1; BR9806384A; CA2256220C

Abstract

A method for cleaning static precipitator and a device thereof. Hot air and steam are repeatedly filled into an oil-collecting sink of the static precipitator at different time or at the same time for heating and melting the oil dirt attaching to the static panels, making the oil dirt drop down into a collecting section. The static panels can be harmlessly cleaned up without disassembly or using any scraper. Hot air also serves to shorten the drying time for the static panels. <IMAGE>

Description

Background of the Invention

The present invention relates to a method for cleaning a static precipitator and a device thereof, in which hot air and steam are used to heat and melt the oil dirt attaching to the static panels, making the oil dirt drop down into a collecting section. Accordingly, the static panels are effectively and harmlessly cleaned up.
In a conventional static precipitator, the oil drops passing through the space between the static panels are ionized by way of high voltage discharging. The ionized oil drops are attracted to attach to the static panels. After a period of use, excess oil drop will accumulate on the surface of the static panels. This will deteriorate the attractive force of the static panels and may lead to short circuit of the static panels or even cause sparks.
Conventionally, the oil dirt accumulating on the static precipitator is cleared in such a manner that the static panels are detached and immerged in a detergent. Alternatively, a detergent is sprayed onto the static panels which are then washed and flushed by clean water. After totally dried, the static panels are installed back into the oil-collecting sink of the static precipitator. Such cleaning procedure is quite troublesome and time-consuming and much waste water will be produced, which is difficult to process. An improved measure has been developed, which employs a sprinkler in the oil-collecting sink to directly sprinkle a detergent and water onto the static panels and wash the same. Accordingly, it is no more necessary to detach the static panels and much labour and time are saved. However, still a great amount of waste water is produced. Moreover, it will be more difficult and time-consuming to dry the static panels in the oil-collecting sink.
Another improved measure has been developed to remove the oil dirt in such a manner that the static panels are circularly moved and in the moving path, a scraper is used to scrape off the oil dirt. In such measure, the static panels tend to deflect during moving. In addition, the static panels are subject to scraping of the scraper for a long time and are likely to damage. Also, such measure has complicated structure.
Furthermore, when maintained, the conventional devices must be stopped for operating and it often takes much time to complete the maintenance. Therefore, the operation of the static precipitator is often interrupted for a long time.
The prior art document DE 23 60 309 provides a method to clean a smoking gas by using a precipitator. For cleaning the precipitator a heating rod as heat source is mentioned or alternatively thereto a hot air or steam impinched pipe. The disadvantage of indirect heating is that high energy is necessary to reach temperatures which are sufficient to achieve a satisfying cleaning effect.
Prior art document DE 461 829 discloses the method for cleaning a precipitation electrode by hot air or hot gas.

SUMMARY OF THE INVENTION

It is primary object of the present invention to provide a method for cleaning precipitator and a device thereof, in which hot air is filled into the oil-collecting sink through a hot air filling pipe for heating and melting the oil dirt attaching to the static panels, making the oil dirt drop down into a collecting section so as to clean up the static panels.
It is a further object of the present invention to provide the above method and device, in which steam is further filled into the oil-collecting sink through a steam filling pipe to further clean up the oil dirt remaining on the static panels.
It is still a further object of the present invention to provide the above method and device, in which sealing devices are disposed near two ends of the oil-collecting sink for sealing the air inlet and air outlet of the oil-collecting sink during heating procedure so as to maintain a high temperature therein.
It is still a further object of the present invention to provide the above method and device, in which the inner side of the front end of the oil-collecting sink is disposed with a flow-guiding filtering screen near the air inlet. The filtering screen serves to filter the coarse pollutant particles entrained by the air. The filtering screen also serves to make the air evenly flow through the static panels to enhance the oil-cleaning effect. An activated carbon filter device is installed in the rear end of the oil-collecting sink. The air flow which is free from the oil drops can further pass through the activated carbon filter device to be filtered from the odor and gas pollutant and then exhausted so as to ensure the quality of the exhausted air.
It is still a further object of the present invention to provide the above method and device, in which a fire device is mounted outside the oil-collecting sink. A thermosensor of the fire device serves to detect the temperature and in the case of abnormal temperature, the thermosensor is able to activate the fire device and the sealing device at the same time to isolate the air and inject a fire-extinguishing material into the oil-collecting sink to extinguish the fire. The sealing device can be a movable door. During the cleaning operation or maintenance of the static precipitator, the movable door is turned to close the air passage of the static precipitator. At this time, the air is guided and exhausted by a bypass. Therefore, the static precipitator can continuously exhaust the oil drop at the same time when maintaining the internal equipments in the oil-collecting sink without interruption of the operation of the static precipitator.
The present invention can be best understood through the following description and accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1: is a flow chart of the oil dirt-cleaning operation of the present invention;
Fig. 2: is a sectional view showing the structure of the cleaning device of the present invention;
Fig. 3: is a view according to Fig. 2, in which the cleaning device is used with sealing devices;
Fig. 4: is a sectional view of another embodiment of the cleaning device of the present invention; and
Fig. 5: is a view according to Fig. 4, seen by another angle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to Fig 1 which shows the flow chart of the present invention. The oil dirt cleaning procedure of the present invention includes the following steps: In step 11 " if it is necessary to seal the oil-collecting sink ", according to the peripheral equipments and actual requirements, it is judged whether it is necessary to seal the oil-collecting sink. If so, step 12 " sealing oil-collecting sink " is performed. If no, then step 13 " filling in hot air " is performed. The hot air is filled in to heat the static panels to make the oil dirt attaching to the surfaces thereof thermally melt and separate therefrom and drop down so as to achieve a preliminary cleaning effect. Then, in step 14 " filling in steam ", steam is used to further heat and melt the oil dirt remaining on the static panels so as to achieve a further cleaning effect. Then, in step 15 " if it is necessary to repeat cleaning ", it is judged whether it is necessary to repeat the cleaning operation. If so, the steps 13, 14 are repeated. Otherwise, step 16 " filling in hot air to dry static panels " is performed so as to shorten the drying time. According to the above procedure, the cleaning operation of the static panels is completed. Alternatively, in the procedure, the filling of hot air and steam can be performed simultaneously to shorten cleaning time and enhance the cleaning effect.
Fig. 2 shows the entire structure of the present invention, which includes an oil-collecting sink 2, static panels 3, hot air filling pipe 4 and steam filling pipe 5. Two ends of the oil-collecting sink 2 are respectively disposed with an air inlet 211 and an air outlet 212. A middle section of the oil-collecting sink 2 is disposed with a recessed collecting section 22. The bottom of the collecting section 22 is disposed with an oil draining pipe 221 communicating with outer side. The static panels 3 are parallelly arranged in the oil-collecting sink 2. The hot air filling pipe 4 and the steam-filling pipe 5 are disposed on one side of the oil-collecting sink 2 adjacent to the air inlet 211. A fire device 6 is additionally mounted outside the oil-collecting sink 2 with a nozzle 61 extending into the oil-collecting sink 2.
After a period of use and when it is necessary to clean up the oil dirt accumulating on the surfaces of the static panels 3, the hot air is filled in through the hot air filling pipe 4 to heat the static panels 3 and melt the oil dirt on the surfaces thereof. The molten oil dirt then gradually drops down into the collecting section 22 of the oil-collecting sink 2 and drained out from the draining pipe 221. After a period of time by which the hot air is filled in, the steam is filled in through the steam-filling pipe 5 to more quickly clean up the oil dirt remaining on the static panels 3 and achieve a further cleaning effect. The hot air and steam are repeatedly filled into the oil-collecting sink 2 so as to quickly and harmlessly clean up the static panels 3. The hot air and steam can be simultaneously filled into the oil-collecting sink to enhance the cleaning effect.
In the case of abnormal temperature in the oil-collecting sink 2 ( for example, the oil dirt on the surfaces of the static panels 3 is burned due to discharging sparks ), a thermosensor of the fire device 6 can detect the temperature to in time activate the fire device 6, making the nozzle 61 inject in fire-extinguishing material for avoiding fire.
Please refer to Fig. 3. Two sealing devices 23 can be disposed on two sides of the oil-collecting sink 2 adjacent to the air inlet and air outlet 211, 212. In the case that the static panels 3 are cleaned or the fire device 6 operates in an emergency ( for example, the oil dirt burns in the oil-collecting sink 2 or at the static panels 3 ), the sealing devices 23 serve to seal the air inlet and outlet 211, 212 to enhance the cleaning or fire-extinguishing effect and protect other relevant equipments from being damaged and ensure safety of personnel and properties.
Please refer to Figs. 4 and 5. In order to achieve a filtering effect and purify the exhausted air, the inner side of the front end of the oil-collecting sink is disposed with a flow-guiding filtering screen 7 near the air inlet 211. The filtering screen 7 serves to preliminarily filter the coarse pollutant particles in the air so as to prevent the internal static panels 3 from being contaminated by such pollutant particles. The filtering screen 7 also serves to even the airflow so as to even and enhance the filtering effect. In addition, an activated carbon filter device 8 is installed in the rear end of the oil-collecting sink 2 near the air outlet 212. The air flow which is free from the oil drops can further pass through the activated carbon filter device 8 to be filtered from the odor and gas pollutant so as to purify the exhausted air.
At least one side of the oil-collecting sink 2 is formed with an openable door which can be opened for taking out or maintaining the above filtering screen 7, static panels 3, activated carbon filter device 8 and other relevant equipments disposed in the oil-collecting sink 2.
As shown in Figs. 4 and 5, the sealing device 23 can be a movable door 24 which can be turned from a lateral side to inner side. The outer side of the movable door 24 is disposed with a bypass 9, whereby when the movable door 24 is turned inward, the air passage of the static precipitator is just closed. At this time, the bypass 9 serves as an air passage. Therefore, the static precipitator can continuously exhaust the oil drop at the same time when taking, disassembling or maintaining the internal equipments in the oil-collecting sink 2. After the maintenance is completed, the movable door 24 is restored to its home position, permitting the oil drops to pass through the air passage in which the static panels 2, filtering screen 7 and activated carbon filter device 8 are located. Therefore, the air exhaustion operation is not interrupted to meet the requirements of actual use.
It should be noted that the above description and accompanying drawings are only used to illustrate some embodiments of the present invention not intended to limit the scope thereof. Modifications of the embodiments are possible within the scope of the appended claims.

Claims

A method for cleaning a static precipitator, comprising the steps of:

filling in hot air to heat static panels (3) to make oil dirt attaching to the surfaces thereof thermally melt and separate therefrom and drop down; and

filling in steam to further heat and melt the oil dirt remaining on the static panels (3) so as to achieve a further cleaning effect.
A method as claimed in claim 1, wherein prior to filling in the hot air, an air inlet (211) and an air outlet (212) of an oil-collecting sink (2) are sealed.
A method as claimed in claim 1, wherein after the steam is filled in, it is judged whether it is necessary to repeat the cleaning operation, if so, the steps of filling in hot air and filling in steam being repeated.
A method as claimed in claim 1, wherein after the static panels (3) are completely cleaned, hot air is further filled in to dry the static panels (3) so as to shorten the drying time thereof.
A method as claimed in claim 1, wherein the steps of filling in hot air and filling in steam are simultaneously performed.
A static precipitator provided with a cleaning device comprising:

an oil-collecting sink (2) two ends of which are respectively disposed with an air inlet (211) and an air outlet (212), the oil-collecting sink (2) being further disposed with an oil draining pipe (221) communicating with outer side;

multiple static panels (3) parallelly arranged in the oil-collecting sink (2), each two adjacent static panels being charged with reverse high DC voltage;

and further characterized in that the cleaning device comprises additionally

at least one hot air filling pipe (4) disposed at one end of the oil-collecting sink (2) near the air inlet (211), whereby hot air is filled into the oil-collecting sink (2) through the hot air filling pipe (4) for heating and melting the oil dirt attached to the static panels (3), the molten oil dirt then dropping down; and

at least one steam filling pipe (5) beside the hot air filling pipe (4), whereby steam is filled into the oil-collecting sink (2) through the steam filling pipe (5) to further clean up the oil dirt remaining on the static panels (3).
A device as claimed in claim 6, wherein a flow-guiding filtering screen (7) is disposed in the front end of the oil-collecting sink (2) near the air inlet (211).
A device as claimed in claim 6 or 7, wherein an activated carbon filter device (8) is disposed in the rear end of the oil-collecting sink (2) near the air outlet (212).
A device as claimed in anyone of the claims 6 to 8, wherein a bottom of the oil-collecting sink (2) is disposed with a recessed collecting section (22) under the static panels (3) for collecting the molten oil dirt dropping thereinto.
A device as claimed in anyone of the claims 6 to 9, wherein a fire device (6) is mounted outside the oil-collecting sink (2) with a nozzle (61) extending into the oil-collecting sink (2), a thermosensor of the fire device (6) serving to detect the temperature, in the case of abnormal temperature, the thermosensor being able to in time activate the fire device (6), making the nozzle (61) inject fire-extinguishing material into the oil-collecting sink (2).
A device as claimed on anyone of the claims 6 to 10, wherein sealing devices (23) are disposed near two ends of the oil-collecting sink (2) for sealing the air inlet (211) and air outlet (212) as necessary.
A device as claimed in anyone of the claims 6 to 11, wherein two ends of the oil-collecting sink (2) are disposed with a bypass (9), whereby when the air inlet (211) and air outlet (212) are sealed by the sealing devices (23), the bypass is opened, serving as an air passage.