JPS6253722A - Method and apparatus for collecting dust - Google Patents

Abstract

PURPOSE:To reduce dust content in the discharge air, by sending back dusts which pass through to the clean side of a section to the dirty side of other sections during shaking off dusts collected on a bag by means of injection of pulse air at each section of the main body of a dust collector. CONSTITUTION:By means of a suction draft fan 8 the dust-laden air is passed through an introducing duct 5 to the dirty side B in each of the sections 1a-1d of the main body of a dust collector 1, while the dust is collected through the filter cloth of bags 4. When the pressure loss of the bags increases, dust is shaken off at each section, selecting at random any one of the sections 1a-1d or selecting sections in the order of arrangement thereof. For example, in the case of shaking off in the section 1b, an off-line damper 7b of a discharge duct 6b is closed and introduction of the dust-laden air is stopped. And a backflow fan 11 is actuated, with only a backflow damper 12b of a connecting duct 10b opened, while high-pressure air being injected through the nozzles of a pulse charge pipe 16. Dust which swirls up partially in the clean side A is led through a backflow duct 10 into other sections being under operation of dust collecting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dust collection method and apparatus for collecting dust from dust-containing air such as exhaust gas generated from various processing equipment such as a factory.

[Technical background of the invention and its problems]

Generally, in order to collect dust from the above-mentioned dust-containing air, a dust collecting device called a bag filter, which is equipped with a large number of bugs inside the device, is often used. In particular, it is a suction type that uses the suction action of a fan installed on the clean air exhaust side to conduct dust-laden air from the dust source to the bag inside the dust collector body (housing) to filter and collect dust. Many of them are of the backwash type, in which the dust is removed by jetting pulsed air at appropriate times to regenerate the bugs.

By the way, in such conventional dust collectors, when the dust collected by the bugs is removed by backwashing pulsed air jetted inside the dust collector body, the bugs are intermittently hit strongly from the inside by the jetting of high-pressure pulsed air. Because the energy of the pulsed air is large, some of the dust attached to the filter cloth layer of the bag is not blown out to the outside (dirty side side) and is scattered inside the bag. If the dust is suspended on the clean side and dust collection is restarted, the floating dust will be sucked into the exhaust duct and come out to the outside, resulting in an increase in the amount of dust on the exhaust side.

(Purpose of the Invention) This invention has been made in view of the above circumstances, and when the bug-collected dust is blown off by backwash pulse air injection in each compartment, the dust that blows from the bugs in the compartment to the clean side side is removed. A dust collection method and its method that can return dust to the dirty side of another compartment without directly exhausting it to the outside through an exhaust duct, thereby reducing the amount of dust coming out to the exhaust side. The purpose is to provide equipment.

[Summary of the invention]

In order to achieve the above object, the dust collection method of the present invention conducts dust-containing air from a dust source through an introduction duct from the dirty side to the clean side in each compartment of the dust collector main body. The dust in the air is filtered and collected by the bug, and the purified air is exhausted to the outside from the clean side of each compartment via the exhaust duct by a suction fan. By injecting pulsed air from the upper end of each compartment, the dust is removed by blowing it off to the bottom of the dust collector body. At the same time, the off-line damper between the compartments is closed, and the dust blowing to the clean side of the compartment is sucked out to the return duct and introduced directly or via the introduction duct to the dirty side of the other compartment for reprocessing. This is what I did.

In addition, in order to achieve the same purpose as described above, the dust collector of the present invention includes a dust collector main body divided into a plurality of compartments each containing a bug that filters and collects dust in dust-containing air, and An introduction duct introduces dust-containing air from a dust source into the dirty side of each compartment, and air that is purified by filtering and collecting dust by bugs in each compartment is exhausted to the outside from the clean side. an exhaust duct and a suction fan, and a backwashing pulse air supply mechanism that removes the dust collected by bugs in each compartment by jetting pulse air from the upper end of each compartment to the lower part of the dust collector body. In the dust collector, an off-line damper is provided at the connection between the clean side side of each compartment and the exhaust duct, and when the dust collected by bugs is removed by jetting pulsed air in each compartment, A damper opening/closing control mechanism is provided to close an off-line damper between the compartment and the exhaust duct, and the air on the clean side in the compartment is sucked out and released into other compartments either directly or through the introduction duct. Dirty
It has a configuration in which a return duct and a return fan are installed on the side.

[Embodiments of the invention]

An embodiment of this invention will be described below.

First, for convenience of explanation, the structure of the dust collector of the present invention will be described first with reference to FIG.
The interior of each of the compartments 1a to 1d is further divided into an upper clean side A and a lower dirty side B by a partition plate 2 with a large number of mounting holes located near the upper end. Hoppers 3 are provided at the bottom of the dirty side B of 1d.

The bugs 4, each having a vertically long bottomed cylindrical shape with the same number of holes as the number of holes, are fixed to each mounting hole of the partition plate 2 in each of the compartments 1a to ld of the dust collector main body 1, with the upper end fitting in each mounting hole. It is provided so as to hang down on the side of the side B. Each of these bags 4 is made of filter cloth such as non-woven fabric.

In the figure, 5 is an introduction duct that introduces dust-containing air from a dust source (not shown) into the dust collector main body 1, and this introduction duct 5 has branched inlet ducts t-5a, 5b, and 5c, respectively.
, 5d to the lower hopper 3 of the dirty side B of each of the compartments 1a to 1d. Also, 6 in the figure
is an exhaust duct for sucking and exhausting the purified air of the dust collector main body 1 to the outside, and this exhaust duct has branched outlet ducts Bat 6b, 6c, and 6d, respectively, and connects to the upper part of each compartment 1a to 1d of the dust collector main body 1. Individually connected to clean side A. Off-line dampers 7a, 7b, 7c, and 7d are provided in the middle of each outlet duct 6a to 6d of this exhaust duct 6, and the damper 7a
~7d are controlled by a damper opening/closing control mechanism consisting of a drive/cylinder, a positioner, a controller, etc. (not shown), and can be opened and closed individually or held in a slightly open state such as half-open. There is. Note that the distal end side of the exhaust duct 6 is connected to an exhaust pipe 9 via a suction fan 8.

In addition, 10 in the figure indicates each compartment 1a to 1 of the dust collector main body 1.
When the collected dust of bug 4 is brushed off every d, some of the dust that flies up inside the bag due to being hit by high-pressure pulsed air is sucked out from the clean side A side of the compartment and used for other dust collection operations. This is a return duct that returns to the dirty side B in the middle compartment, and one end of this returns to the upper clean side A of each compartment 1a to 1d of the dust collector main body 1 via branched connection ducts 10a, 10b, 10c, and 10d. The other end is connected to the introduction duct 5 via the return fan 11. Further, a damper 12a for return is provided in the middle of each connecting duct 10a to 10d of this return duct 10.

12 b, 12 c, 12 d are provided,
They are opened and closed by an opening/closing control mechanism (not shown).

In the figure, reference numeral 13 denotes a backwash pulse air supply mechanism disposed on the upper part of the dust collector main body 1, which supplies each of the compartments 1a through a header 14 that stores high-pressure air and a diaphragm valve 15 that opens and closes in an electrical sequence. A pulse supply pipe 16 extending into each upper clean side A of ~1d
A pulse air jet nozzle is formed in each pulse supply pipe 16 facing the upper end opening of each bag 4.

Next, the dust collection method of the present invention using the dust collection device configured as described above will be explained with reference to FIGS. 1 and 2. First, the suction fan 8 on the exhaust duct 6 side is operated, and its suction action Dust-containing air from the dust source is introduced from the duct 5 to the dust collector main body 1 via each branch inlet duct 5a to 5d.
is introduced into the lower dirty side B of each of the compartments 1a to 1d. Then, the dust-containing air is passed through the filter cloth of the bag 4 to filter and collect the dust. The clean air that has passed through each bag 4 is sucked into the exhaust duct 6 from the upper clean side A in each of the compartments 1a to 1d through each outlet duct 6a to 6d, and is exhausted to the outdoors through an exhaust pipe 9.

In this way, dust collection operation of the dust-containing air is performed, and when the time for dust removal comes by a timer or a pressure drop resistance detector of a bug during the operation, one of the compartments 1a to 1d is selected arbitrarily or according to the arrangement order. Then, the bug collecting dust inside the selected compartment is brushed off. For example, when performing an operation to remove the bug collecting dust in the second compartment lb from the left as shown in FIG. The off-line damper 7b of the outlet duct 6b of the exhaust duct 6 connected to the compartment 1b is closed as shown in FIG.
The dust-containing airflow from the inlet duct 5b of the introduction duct 5 into the compartment 1b is substantially stopped by preventing strong suction from the exhaust duct 6 side. On the other hand, among the return dampers 12a to 12d, which are all closed during normal dust collection operation, the return damper 1 of the connecting duct 10b connected to the selected compartment 1b
2b is opened by the opening/closing mechanism a little later than the opening of the off-line damper 6b, and the return fan 11 is operated.

In this state, the diaphragm valve 15 of the backwash pulse air supply mechanism 13 is opened and closed for a short period of time, and the high pressure air (approximately 9/C'dG in 2 to 1) stored in the header 14 is released into the pulse supply pipe 16. Pulse air is injected from each nozzle into each bag 4 in the compartment from its upper end opening. As a result, the pulsed air is blown out by strongly hitting the bug 4 from the inside without being hindered by the dust-containing airflow, and the bug-collected dust is efficiently brushed off to the outer dirty side B, and the air is blown out to the lower hopper. 3 Let it settle and accumulate at the lower end. In addition, some of the dust that flies up inside Bug 4 during dust removal is clean side A.
The air is drawn out by moderate suction into the return duct 10, and sent to the introduction duct 5, together with the dust-containing air, to the other compartment 1a during the dust collection operation.

The dust is returned to the dirty side B of lc and ld and collected again. Incidentally, the dust accumulated in the lower hopper 3 is removed to the outside in a timely manner. In addition, while the bug collection dust is being removed from one compartment 1b, the other compartments 1a and 1b are
c, ld are respective offline dampers 6a, 6c, 6d
Since the duct remains open, the returned dust is sucked in together with the dust-containing air from the introduction duct to continue the filtration and dust collection operation.

Therefore, the dust that partially flies up inward from the filter cloth layer of the bag 4 in the compartment lb and floats on the clean side A is not left as it is, and is passed through the return duct 10 to the other compartment during the dust collection operation. 1a.

While returning to the dirty side B of lc and ld to collect dust again, the bug-collected dust in the compartment lb is brushed off. In this way, when the dust collected by the bugs is completely removed, the operation of the backwash pulse air supply mechanism 13 is stopped.
Thereafter, when the return damper 12b is closed by the opening/closing mechanism, the off-line damper 7b is opened by the damper opening/closing control mechanism to resume dust collection in the compartment 1b.

When dust collection is resumed, the off-line damper 7b is not fully opened all at once, but is kept slightly open, such as half-open, as shown in FIG. 2, to perform preliminary dust collection for several seconds. In other words, the suction effect from the exhaust duct 6 side into the compartment lb is not increased rapidly, but is given a little at first.
Dust-containing air is slowly sucked and introduced from the introduction duct 5 side, thereby avoiding rapid conduction of the dust-containing air to the filter cloth layer of the opened bag 4 immediately after regeneration, and the dust is transferred to the clean side A.
The dust is properly attached to the surface of the filter cloth of the bag 4 while preventing the dust from blowing through or penetrating deeply into the filter cloth layer. After preliminarily collecting dust in this manner, the off-line damper 7b is fully opened to bring about a normal dust collection state.

In this way, after bug regeneration and dust collection restart in one compartment 1b, bug regeneration in the next selected compartment is performed in the same manner as above, and when the regeneration is completed, preliminary dust collection is performed in the same manner as above, and then dust collection is restarted. do. In this way, efficient dust collection operation of dust-containing air is carried out continuously for a long period of time without causing high pressure loss in the bag while regenerating the bag in each compartment.

〔Effect of the invention〕

Since this invention is made as described above, when the bug-collected dust is removed by backwashing pulsed air injection in each compartment, the dust blown from the bugs in the compartment to the clean side is directly passed to the outside through the exhaust duct. This is an extremely excellent dust collection method and apparatus that can return the dust to the dirty side of another compartment without exhausting the air to the outside, thereby reducing the amount of dust coming out to the exhaust side.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a schematic diagram of the entire device, and Fig. 2 is a diagram showing the off-line damper, return damper, and backwashing pulsed air dust removal operation. It is a time chart figure. 1...Dust collector main body, 1a~IC...Division room, 2...
・Partition plate, A...Clean side, B...Dirty side, 3...Lower hopper, 4...Bug, 5
...Introduction duct, 5a...Inlet duct, 6.
...Exhaust duct, 6a to 6d...Outlet duct, 7a to 7d...Offline damper, 8...Suction fan, 9...Exhaust tube, 10...Return duct, 10a
~10d...Branch connection duct, 11...Returning fan, 12a-12d...Returning damper, 13...
Backwash pulse supply mechanism, 14... Header, 15... Diaphragm valve, 16... Pulse supply pipe.

Claims (2)

[Claims] (1) Dust-containing air from a dust source is conducted from the dirty side to the clean side in each compartment of the dust collector body through an introduction duct, and the dust in the air is filtered and collected by a bug; The purified air is exhausted to the outside from the clean side of each compartment by a suction fan via an exhaust duct, and the dust collected in the bugs is removed by injecting pulsed air from the top side of each compartment at appropriate times. In the dust collection method in which the dust is removed by blowing it into the lower part of the dust collector body, when the dust collected by bugs is removed by jetting pulsed air in each compartment, the off-line damper between the compartment and the exhaust duct is closed, and A dust collection method characterized in that air on the clean side of the compartment is sucked into a return duct and introduced into the dirty side of another compartment either directly or via an introduction duct. (2) The main body of the dust collector is divided into multiple compartments each containing a bug that filters and collects dust in the dust-containing air, and the dust-containing air from the dust source is placed on the dirty side of each compartment of the main body of the dust collector. An exhaust duct and suction fan that exhausts purified air from the clean side to the outside by filtering and collecting dust by bugs in each compartment, and an exhaust duct and suction fan to exhaust dust from the clean side to the outside, and dust collected by bugs in each compartment. In a dust collector equipped with a backwash pulse air supply mechanism that blows off dust to the lower part of the dust collector main body and removes the dust by injecting pulse air from the upper end side of each compartment in a timely manner, it is possible to clean each compartment. An off-line damper is provided at each connection between the side and the exhaust duct, and a damper that closes the off-line damper between the relevant compartment and the exhaust duct when dust collected by bugs is removed by jetting pulsed air in each compartment. An opening/closing control mechanism is provided, and a return duct and a return fan are provided to suck and draw air from the clean side of the compartment and introduce it directly or through an introduction duct to the dirty side of another compartment. A dust collector characterized by: