KR20010060712A - Method and apparatus for remove dust in filtering machine - Google Patents

Abstract

PURPOSE: Provided are a method and an apparatus for cleaning a dust collector by collecting dust on the outside of a filter bag and dusting off the filter bag using backwash air, to increase a filtering speed and to reduce operating costs. CONSTITUTION: The method comprises the steps of: collecting dust and discharging cleaned gas to a stack(34); measuring the loss of pressure by a manometer(29), stopping the operation of an inhaling fan(21) according to the measured value and backwashing outside air into a dust-collecting room(11) by operating a backwashing fan(25); and cleaning dust attached on the outside of the filter bag(12). The apparatus includes the inhaling fan(21), the backwashing fan(25) and a controller(30) to control dampers(23,27) of backwashing lines(22,26), a dust-collecting hood(19), dampers(18a,19a) of a backwashing line(18), the inhaling fan(21) and the backwashing fan(25).

Description

Dust collection method and apparatus of dust collector {METHOD AND APPARATUS FOR REMOVE DUST IN FILTERING MACHINE}

The present invention provides a dust collecting method and apparatus for collecting dust on the outer surface of a filter bag made of a nonwoven fabric, and dust collecting dust attached to the filter bag as an external air backwashed by a backflow method to reduce the operating cost and increase the filtration speed. It is about.

In general, the filter dust collecting technology is a method of collecting the dust contained in the exhaust gas by using a filter cloth, and is widely used in the industry along with the electrostatic dust collecting technology, cleaning dust collecting technology.

Filtration and dust collection technology can be used in most industrial dust generation process, and representative industrial processes can be used in steel process, incineration process, cement process, combustion process, papermaking process and coke process.

In general, the bag filter may vary depending on the type of filter cloth, the method of installing the filter cloth in the bag, the method of dedusting the dust collected on the surface of the bag, and depending on the method of dust removal, the vibration cleaning (shake cleaning), reverse air cleaning, Shock-jet cleaning methods are known, among which counter-air and dust-free dust removal methods are widely used in the industry, and these methods have their characteristics.

That is, in the reverse airflow dedusting method, as shown in Fig. 1 (a) and (b), the dust containing gas is introduced into the unit dust collection chamber 31 by the suction force of the dust collecting fan 33 to attach dust to the filter cloth 32. After stopping for a certain time, the inflow of the impregnated gas into the dust collecting chamber 31 is stopped, and blows external air in a direction opposite to the inflow direction of the impregnated gas to dedust dust adhered to the surface of the filter cloth 32. The characteristic of this method is an internal filtration method in which dust is collected on the inner surface of the filter cloth 32, and the filter cloth uses a woven filter.

Reference numeral 34 denotes a stack from which dust-free gas is discharged, and 39 denotes a rotary valve.

In addition, the filter cloth 32 in the dust collecting chamber 31 is fixed at the same time as the upper and lower beams 35a, 35b, as shown in Fig. 1 (c), the upper portion is connected to the spring ring 36 The tension is adjusted and attached to the upper part of the dust collecting chamber 31. At this time, the lower part of the filter cloth 32 is open, and the upper part is blocked.

The reverse airflow dedusting method is characterized in that the whole dust collecting device is composed of several unit dust collecting chambers 31, and since the filtration speed is generally low, the flow rate of processing gas per unit area of the filter cloth 32 is small, so that the installation area of the whole dust collecting device is On the other hand, since it is a low energy dedusting method, the dedusting strength given to the filter cloth 32 is low, the service life of the filter cloth 32 is long, and the operating cost of the dust collector is low.

In addition, the impact air dedusting method is to dedust dust attached to the surface of the filter cloth by using high pressure compressed air (usually 3 to 7 atmospheres) through the injection nozzle, which is characterized by an outer filtration in which dust is collected on the outer surface of the filter cloth. Method, the filter bag uses a non-woven (felt).

The filter cloth in the dust collecting chamber has a bag cage installed therein to support the filter cloth, the lower part of the filter cloth is blocked, the upper part is open, and is connected to the dust collecting chamber upper part through the hardware support.

Since this method uses high dust extraction energy using compressed air, the filtration speed can be increased and the dust collector main body can be made small. On the other hand, the operation cost of the dust collector increases due to the use of high pressure compressed air, and the length of the filter cloth is increased. When it was enlarged, there was a problem in that the dust was not properly made since the dust removal force did not reach the lower end of the filter cloth.

Therefore, the conventional backflow dedusting type filter precipitator using the nonwoven fabric uses internal filtration and low pressure air at the time of dedusting, so that the filtration rate cannot be increased.

In addition, the impact air dedusting type can increase the filtration speed, which can reduce the size of the dust collecting device than the backflow dedusting type on the basis of the same exhaust gas throughput, but the operation cost of the equipment is excessive due to the use of high pressure compressed air. will be.

Therefore, the present invention has been devised in view of such a conventional problem, and its object is to provide a high speed of filtering dust contained in the dust-containing gas, and to collect dust attached to the filter cloth as low pressure external air, so that dust collection equipment The present invention aims to provide a dust extraction method that can reduce the operating cost of the dust collector.

In addition, another object of the present invention is to filter the dust contained in the dust containing gas is high, the dust attached to the filter cloth as a low pressure external air can be dedusted to reduce the operating cost of the dust collection equipment, It is intended to provide a dust collector of a dust collector that can reduce an installation space.

Figure 1 (a) (b) (c) is a schematic diagram showing a dust collector of a general reverse air flow type,

Figure 2 is a perspective view showing a dust collector of the dust collector according to the present invention,

3 is a schematic view showing a dust extraction apparatus of the dust collector according to the present invention;

Figure 4 is a graph showing the results of the experiment to perform the dust-collecting, dust-dusting operation continuously using the dust collector of the dust collector according to the present invention

* Explanation of symbols for the main parts of the drawings *

11 .... Dust collection room 12 .... Filter cloth

17 .... Dust outlet 19 .... Dust collection hood

21 .... suction fan ?? 22 .... suction line

23,27 .... Damper 25 .... Backwash Fan

26 .... Backwash Line 29 .... Differential Pressure Gauge

30 .... Controller 34 .... Stack

As a technical configuration for achieving the above object, the present invention,

In the method for collecting dust in dust-containing gas and dedusting,

A dust collecting step of attaching dust in the dust-containing gas introduced into the dust collecting chamber by the suction force of the suction fan to the outer surface of the filter cloth and collecting the dust-filtered clean gas into the stack;

The pressure loss in the dust collecting chamber caused by the dust attached to the filter bag is measured as a differential pressure gauge, the driving of the suction fan is stopped based on the measured value of the differential pressure gauge, and the reverse washing fan is operated to enter the dust collecting chamber. A backwashing step of backwashing the external air; And,

It is provided by a dust extraction method of a dust collector; comprising a dust-removing step of dropping and removing the dust attached to the outer surface of the filter bag to the lower by the backwash air forcibly introduced into the dust chamber.

In addition, as a technical configuration for achieving the above object, the present invention,

In the dust collecting equipment which removes the dust in the dust containing the dust collection hood which the dust-containing gas is input from the dust generating source, the dust chamber which has a plurality of filter bags built-in, and the dust discharge port which exhausted dust is discharged,

Equipped with a suction line installed on one side of the dust collecting chamber so as to generate a suction force to suck the dust containing gas into the dust collecting chamber through the dust collection hood and to discharge the filtered gas to the outside while passing through the filter bag. Losing dust collecting fan;

A backwash fan provided in a backwash line installed on the other outer surface of the dust collecting chamber to supply external air into the dust collecting chamber so that dust attached to the filter bag can be dropped; And,

Receiving the measured value of the differential pressure gauge for measuring the pressure loss in the dust collecting chamber to control the opening degree of the damper installed in the suction, backwash line, the dust collection hood, the opening degree of the damper installed in the backwash exhaust line, and the starting of the suction fan and backwash fan. By providing a dust collector of the dust collector, characterized in that it comprises a controller.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a perspective view showing a dust collector of the dust collector according to the present invention, Figure 3 is a schematic diagram showing a dust collector of the dust collector according to the present invention.

Dust collection method of the dust collector according to the present invention is composed of a dust collection step, backwashing step and dust removal step to increase the filtration rate of the dust containing gas, and reduce the installation operating cost, the dust collecting step of filtering the dust contained in the dust containing gas By operating the suction fan 21 of the suction line 22 connected to the truth 11, the dust-containing gas is sucked into the dust collecting chamber 11 from the dust generating source through the dust collecting hood 19, and into the dust collecting chamber 11. The suctioned dust gas passes through the filter bag 12 and the dust is attached to the filter bag 12, and the clean gas from which the dust is removed is the suction line 22 and the suction fan 21 in which the damper 23 is opened. Exhaust the clean gas to the outside while passing through.

In addition, the backwashing step is to supply low-pressure external air into the dust collecting chamber 11, and the dust collecting chamber 11 is relatively increased as the amount of dust attached to the outer surface of the filter bag 12 increases. The controller 30 which receives the measured value of the differential pressure gauge 29 and compares it with the set value when the measured value becomes more than the set value based on the measured value of the differential pressure gauge 29 which measures the pressure loss in the. Stop the driving of the suction fan 21, cut off the damper 23 of the suction line 22, and then open the damper 27 installed in the backwash line 26, and backwash fan 25 To operate to supply external air into the dust collecting chamber (11).

Continuously, the dust exhausting step supplies dust backing to the outer surface of the filter bag 12 by supplying external back air forced into the dust collecting chamber 10 to the open upper portion of the filter bag 12. ? Clear and discharge the dust collected in a certain amount collected in the dust outlet 17 to the outside.

On the other hand, the dust collector of the dust collector according to the present invention, as shown in Figure 3, the dust collection hood 19, the dust collecting gas is introduced from the dust generating source, the dust collecting chamber 11 containing a plurality of filter bags 12 and , Equipped with a dust discharge port 17 through which dust is discharged and provided in a dust collecting chamber 11 for removing dust in the dust containing gas, comprising a suction fan 21, a backwash fan 25, a controller 30, and the like. do.

That is, the suction fan 21 generates a suction force to suck the dust gas from the dust generation source through the dust collection hood 19 into the dust chamber 10, and cleans the filter while passing through the filter cloth 12. It is installed on the outer surface of one side of the dust collecting chamber 11 to discharge the gas to the outside, the damper 23 is mounted to the suction line 22 is installed.

In this case, the filter bag 12 is a non-woven fabric which is provided with a plurality of upper supports 15, such as a bagcage or a retainer, the upper part of which is open and the lower part of which is closed so that dust is attached to the outer surface. It consists of.

In addition, the reverse washing fan 25, which is operated opposite to the suction fan 21, may supply the external backwashing air capable of dropping dust attached to the filter bag 12 into the dust collecting chamber 11. It is installed on the other outer surface of 11), and is attached to the back washing line 26 provided with the damper 27.

In addition, the controller 30 which controls the start of the suction fan 21 and the backwash fan 25 frequently receives a pressure loss in the dust collecting chamber 11 which is raised as dust is collected in the filter bag 12. The detection stage is electrically connected to the differential pressure gauge 29 disposed at the upper and lower portions of the filter bag 12 so as to receive the measured value of the differential pressure gauge 29 according to the measured value of the differential pressure gauge 29. The opening degree of the dampers 23 and 27 installed in the suction and backwashing lines 22 and 26 is controlled, and the opening degree of the damper 19a and 18a provided in the dust collecting hood 19 and the backwashing line 18 is controlled. On the other hand, while controlling the operation of the suction fan 21 for generating a suction force to enable the dust collection in the dust collecting chamber 11, and the reverse washing fan 25 for supplying the backwash air from the outside.

In FIG. 3, reference numeral 7 denotes a dust injector, and 8 denotes a compressed air line.

The operation of the present invention having the configuration as described above will be described.

First, in the dust collecting chamber 11, the damper 27 of the backwash line 26 is closed, and the damper 23 is opened in the initial state in which the damper 18a of the backwash line 18 is closed. When the suction fan 21 of the suction line 22 is activated to generate the suction pressure in the dust collecting chamber 11, the dust-containing gas is collected from the dust generating source through the dust collecting hood 19 in which the damper 19a is opened. (11) is forced to flow into.

In addition, the dust-containing gas introduced into the dust collecting chamber 11 is sucked upward through the filter bag 12 mounted on the upper support 15 so that the upper part is opened inside the dust collecting chamber 11 and the lower part is sealed. While the dust is attached to the outer surface of the filter bag 12 made of a non-woven fabric, the dust is filtered clean air is discharged to the outside through the stack 34 through the suction line 22, the suction fan 21.

Here, during the dust collecting operation in which dust of the dust-containing gas is filtered in the filter bag 12 of the dust collecting chamber 11, the differential pressure gauge 29 is provided at the upper and lower portions of the filter bag 12 for a predetermined time interval. Pressure loss is measured, and the measured value of the pressure loss is transmitted to the controller 30, and when the measured value is more than the set value in the controller 30, it is excessive of the amount of dust attached to the filter bag 12. Since it can be determined that further dust collection is difficult, backwashing air is injected into the dust collecting chamber 11 to perform backwashing.

That is, the pressure loss in the dust collecting chamber 11, which had a pressure loss of 150 mmAq or less in the normal dust collecting operation, was excessively collected in the filter bag 12, and the pressure loss in the dust collecting chamber 11 was measured. When the value is 200 to 300 mmAq or more, since the air volume due to the desired suction force is not generated, the start of the suction fan 21 is stopped, and the damper 23 and the dust collection hood 19 of the suction line 22 are stopped. While the damper 19a is closed, the backwash fan 25 is operated while the damper 27 of the backwashing line 27 and the damper 18a of the backwashing line 18 are opened to operate the low pressure external air. Feed into the truth (11).

Subsequently, when the low pressure backwashing outside air is supplied into the dust collecting chamber 11, the dust attached to the outer surface of the filter bag 12 is eliminated and removed downward by the backwashed outside air, and the removed dust is discharged to the dust outlet. The collected dust is discharged to the outside by an open rotary valve, and the backwashing air passing through this to remove the dust attached to the outer surface of the filter bag passes through the backwashing line 18 having the damper 18a opened. Through the stack 35 is exhausted to the outside.

Here, the greater the backwashing amount of the backwashing fan 25 used for dedusting is advantageous for the work of dedusting dust attached to the filter bag 12, but the operating cost required for dedusting increases, so that It is preferable to set smaller than the amount of dust collection winds.

<Example>

Nine filter bags 12 are mounted in the dust collecting chamber 11, and the maximum amount of dust collecting air of the dust collecting fan 21 is 40 m ³ / min, and the maximum amount of back washing air of the back washing fan 25 is 30 m ³ / min. The dust used in the experiment was used by sampling the dust collected in the actual filter dust collector of the sintering plant, the experiment was carried out under the following experimental conditions.

-Filter bag specification

1) Filter bag type: Non-woven fabric, 2) Filter bag size: Diameter 150mm, 3) Length 3000mm, 4) Total filtration area 12.7 ² ,

-Dust collection test condition

1) Air collection volume: 19m ³ / min 2) Filtration speed: 1.5m / min 3) Inlet gas temperature: 26 ℃ 4) Inlet concentration: 10g / Nm ³ 5) Dust type: Sintered dust 6) Dust characteristics: Average particle size 29.2 ㎛, true specific gravity 3.3g / cm ³ 7) backwash flow rate 8.4m ³ / min 8) back washing time: 60 seconds

The most important factor in the performance of bag filter is the dust removal performance, and the criterion for determining the dust removal performance is the pressure loss. The standard of the management of the pressure loss during operation of the conventional filter dust collector is 150mmAq or less, if the pressure loss is 200 to 300mmAq or more, the desired air volume does not come out to replace the filter bag (12).

Figure 4 is a graph showing the results of the experiment to perform the dust-collecting, dust-collecting operation continuously using the dust collector of the dust collector according to the present invention, when dust is dusted up to 120mmAq pressure loss in a given condition at a given backwash condition When exhaustion was carried out, the pressure loss was found to decrease to 20 to 30mmAq.

These results were very similar when five consecutive experiments were carried out, and it would be expected that similar trends would occur even if the dust collection and exhaustion experiments were carried out continuously.

It is remarkable in the above experimental conditions that the filtration rate of 1.5m / min at the time of dust collection is larger than the conventional method since the filtration rate of the dust collector is larger than 0.9 to 1.2m / min at the time of normal backflow dust extraction. It is showing that there is. Accordingly, the experimental results show that the dust collector having the dust extraction device of the present invention is superior to the conventional dust collector.

According to the present invention having the above-described configuration, the dust collection is made by the outer filtration, and the dust is removed by backwashing the low pressure external air, so that the filtration rate is larger than the conventional backflow dedusting based on the same exhaust gas treatment. Since it is possible to significantly reduce the installation space of the device, since the dust can be carried out as low pressure external air, the effect that the operating cost can be significantly lowered compared to the conventional impact air type.

Claims (5)

In the method for collecting dust in dust-containing gas and dedusting, The dust in the dust-containing gas introduced into the dust collecting chamber 11 by the suction force of the suction fan 21 is attached to the outer surface of the filter cloth 12 and is collected, and the dust is filtered and discharged to the stack 34. Dust collecting step; The pressure loss in the dust collecting chamber 11 generated by the dust attached to the filter bag 12 is measured as a differential pressure gauge 29, and the suction fan (based on the measured value of the differential pressure gauge 29) A backwashing step of stopping the driving of the 21 and operating the backwash fan 25 to backwash the outside air into the dust collecting chamber 11; And, And a dust removal step of dropping and removing the dust attached to the outer surface of the filter bag (12) by the back washing air forced into the dust collecting chamber (11) to remove the dust. Dust collecting hood 19 into which the dust-containing gas is introduced from the dust generating source, dust collecting chamber 11 having a plurality of filter bags 12 therein, and dust discharge port 17 through which the dust is discharged are provided, In the dust collection equipment to remove, The dust collecting chamber 11 generates a suction force capable of sucking the dust containing gas into the dust collecting chamber 11 through the dust collecting hood 19, and discharges the filtered gas to the outside while passing through the filter bag 12. A dust collecting fan 21 provided on the suction line 22 installed on one side of the outer surface; A backwashing fan provided on the backwashing line 26 provided on the other outer surface of the dust collecting chamber 11 to supply external air into the dust collecting chamber 11 so that dust attached to the filter bag 12 may be eliminated ( 25); And, Receiving the measured value of the differential pressure gauge 29 for measuring the pressure loss in the dust chamber 11, the opening degree of the dampers 23, 27 installed in the suction, backwash line 22, 26, dust collection hood 19 And a controller (30) for controlling the opening degree of the dampers (18a) and (19a) installed in the backwashing line (18) and the starting of the suction fan (21) and the backwashing fan (25). Dust removal device. The method of claim 2, The filter bag 12 is an upper support 15 such as a bagcage or a retainer, the upper part of which is open, and the lower part of the filter bag 12 is installed in a plurality of non-woven fabrics to which dust can be attached to the outer surface. Dust collector of the dust collector, characterized in that. The method of claim 2 Dust collecting device of the dust collector, characterized in that the backwashing air amount of the backwashing fan (25) is set smaller than the amount of dust collecting air of the dust collecting fan (21). The method of claim 2 When the value of the pressure loss measured in the dust collecting chamber 11 is 200 to 300 mmAq or more, the air flow due to the desired suction force is not generated. Therefore, starting of the suction fan 21 is stopped, and the suction line 22 is stopped. The damper 23 of the dust collector 19, the damper 19a of the dust collection hood 19 is closed, while the damper 27 of the backwash line 27 and the damper 18a of the backwash line 18 are opened. 25) to operate the dust collector of the dust collector, characterized in that for supplying low-pressure external air into the dust chamber (11).