JPH0557010B2 - - Google Patents

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 collection device called a bag filter, which has a large number of bugs installed 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 a dust source to a bag inside the dust collector body (housing) to filter and collect dust. Many of them are of the backwash type, which removes the dust by timely injection of pulsed air to make the bugs appear again.

By the way, in such conventional dust collectors, when the dust collected by bugs is removed by backwashing pulse air injection in the dust collector body, dust-containing air is introduced into the dust collector body from the introduction duct by suction from the fan on the exhaust duct side. , the jetting direction of the backwashing pulsed air is completely opposite to the dust-containing air flow, so even if high-pressure pulsed air is jetted, the dust collected by bugs cannot be removed. In addition to being inefficient, the dust once separated from the bugs is pushed back by the dust-containing air, making it difficult for the dust to settle in the lower hopper, causing it to re-adhere to the bugs.

Therefore, a damper is installed in the middle of the exhaust duct, and when the dust collected in the dust collector is removed, the damper is closed to stop the suction action on the exhaust duct, and this causes the dust-laden air to be sucked into the dust collector from the introduction duct. Some attempts have been made to increase the effect of dust removal by backwashing pulsed air by preventing electrical conduction, but in such cases, the damper, which was closed when dust was removed, is fully opened when the dust is removed. When dust collection is restarted, the suction pressure on the exhaust duct side suddenly acts inside the dust collector body, so the dust-containing air from the introduction duct is conducted vigorously to the bag, and as a result, the above-mentioned pulse injection There has been a problem in that dust blows through the filter cloth layer, such as non-woven fabric, of the opened bag and exits from the clean side to the exhaust duct, resulting in a significant increase in the amount of dust on the exhaust side. In addition, dust penetrates deep into the filter cloth layer of the bag, causing rapid clogging, and the pressure drop resistance of the bag quickly increases, and the dust removal effect of the next backwash pulse air is significantly reduced. There was a problem.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The dust collected by the bugs is efficiently removed by backwashing pulsed air injection, and at the end of the removal, dust collection is resumed after avoiding rapid conduction of the dust-containing air flow to the bag filter cloth layer. This prevents clogging caused by blowing through to the exhaust side or biting deep into the filter cloth layer, reducing the amount of dust coming out on the exhaust side, improving the bug regeneration effect, and reducing the bag pressure. It is useful for energy saving and cost saving by reducing losses, and it is also an excellent method because it can conduct the dust that is partially blown up when dust is removed to other compartments and re-collect it without exhausting it to the outside. Dust collection effect can be obtained.

The purpose of this invention is to provide a dust collection method and device.

[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 collection source to the bag through an introduction duct from the dirty side of each divided compartment of the dust collector main body. The dust in the air is collected by filtration, and the purified air is exhausted from the clean side of each compartment to the outside via an exhaust duct by a suction fan, and the dust collected in the bugs is removed from each compartment as needed. By shifting the timing and injecting pulsed air into the bug from the upper end side, it is removed by blowing it off to the bottom of the dust collector body, and the dust collection operation continues in compartments other than the compartment where the dust collected by the bug is being brushed off. In the dust collection method, when dust collected by bugs is removed by jetting pulsed air in each compartment of the dust collector main body, the off-line dapan between the clean side of the compartment and the exhaust duct is closed, and Part of the dust that flies up on the clean side of the compartment is sucked out via the return duct and introduced into the dirty side of the other compartment for re-collection, so that the dust can be exhausted from the compartment when dust collection is resumed later. To prevent dust from flowing into the duct, and when the bug collection dust is finished being removed, the suction of dust from the compartment to the return duct is stopped, and the off-line damper is slightly opened to allow the dust to blow through to the exhaust side. Preliminary dust collection is performed while avoiding rapid conduction of dust-containing air to the bag filter cloth layer in order to prevent clogging due to digging deep into the filter cloth layer, and then the off-line damper is fully opened to prevent clogging in the compartment. This feature is characterized by restarting dust collection.

In addition, in order to accomplish the same purpose as described above, the dust collector of the present invention has an interior divided into a plurality of compartments, and a bug that filters and collects dust in the dust-containing air in each compartment. Built-in dust collector body,
There is an introduction duct that introduces dust-containing air from a dust source into the dirty side of each compartment of the dust collector, and a bug inside each compartment that filters and collects dust to transport purified air into the compartment. The exhaust duct and suction fan exhaust the air from the clean side to the outside, and the dust collected in the bag is blown to the bottom of the dust collector body by injecting pulsed air from the upper end into the bag at different timings for each compartment. In a dust collector equipped with a backwash pulse air supply mechanism that removes air by dropping, an off-line damper is provided at the connection between the clean side and the exhaust duct in each compartment of the dust collector main body, and A return duct with a return fan for sucking out dust from the clean side and conducting it to the dust-containing air introduction duct, and a return dan that individually disconnects communication between the return duct and each compartment are provided, and a pulse is generated for each compartment. When blowing off bug-collected dust by air injection, the off-line damper of the relevant compartment is closed and the return damper is opened, and when the bug-collected dust has been removed, the return damper of the relevant compartment is closed and the offline damper is operated for a predetermined period of time. The damper is characterized by being configured with a damper opening/closing control mechanism that opens the damper slightly and then fully opens it.

[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 inside 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,
Further, a hopper 3 is provided at the lower part of the dirty side B of each of the compartments 1a to 1d.
The dust collector body 1 has the same number of vertically long bottomed cylindrical bugs 4 that are fixed with their upper end openings fitted into the respective mounting holes of the partition plate 2 in each of the compartments 1a to 1d of the dust collector body 1 as dust collectors. It is provided in a state where it hangs down to the side B side. Each of these bags 4 is made of filter cloth such as non-woven fabric.

In the figure, reference numeral 5 denotes 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 introduces air containing dust into the dust collector body 1 through branched inlet ducts 5a, 5b, 5c, and 5d, respectively. It is connected to the lower hopper 3 of the dirty side B of each of the compartments 1a to 1d. Reference numeral 6 in the figure is an exhaust duct that sucks and exhausts the purified air from the dust collector main body 1 to the outside, and this exhaust duct has branched outlet ducts 6a, 6b, 6c, and 6d, respectively, to each section of the dust collector main body 1. They are individually connected to the upper clean side A of the compartments 1a to 1d. 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 these dampers 7a to 7d are operated by a damper opening/closing control mechanism consisting of a drive cylinder, a positioner, a controller, etc. (not shown). controlled,
They can be opened and closed individually or held slightly open, such as half-open.
Note that the distal end side of the exhaust duct 6 is connected to an exhaust pipe 9 via a suction fan 8.

In the figure, reference numeral 10 denotes a backwash pulse air supply mechanism disposed on the upper part of the dust collector main body 1, which supplies air to each of the compartments 1a through a header 11 that stores high-pressure air and a diaphragm valve 12 that opens and closes in an electrical sequence. It consists of a pulse supply pipe 13 extending into each upper clean side A of ~1d,
A pulse air jet nozzle is formed in each pulse supply pipe 13 so as to face the upper end opening of each bag 4 .

In addition, 14 in the figure refers to dust that is partly blown up inside the bag due to being hit by high-pressure pulsed air when the collected dust of the bug 4 is removed from each of the compartments 1a to 1d of the dust collector main body 1. This is a return duct that draws suction from the clean side A side of the chamber and returns it to the dirty side B of the other compartment where dust collection is being performed, and this is carried out via connecting ducts 14a, 14b, 14c, and 14d, each of which has one end branched. It is connected to the upper clean side A of each compartment 1a to 1d of the dust collector main body 1, and the other end is connected to the introduction duct 5 via the return fan 15. Also, each connection duct 1 of this regression duct 14
Return dampers 16a, 1 are installed between 4a and 14d.
6b, 16c, and 16d are provided, and are configured to be opened and closed individually by an opening/closing control mechanism (not shown).

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 into each compartment 1 of the dust collector main body 1 via each branch inlet duct 5a to 5d.
It is introduced into the lower dirty side B within a 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 sent from the upper clean side A in each compartment 1a to 1d to each outlet duct 6a.
~6d into the exhaust duct 6 and the exhaust pipe 9
Exhaust the air from outside.

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 loss resistance detector of the bag, etc. during the operation, the above-mentioned compartment 1a
-1d is selected arbitrarily or according to the arrangement order, and the operation of brushing off the bug collecting dust in the selected compartment is performed. For example, when performing an operation to remove the bug collecting dust from the second compartment 1b from the left as shown in FIG. The high pressure air (approximately 2 to 7 kg/cm ² G) stored in the chamber 11 is fed under pressure to the pulse supply tube 13, and the pulsed air is supplied from each nozzle into each bag 4 of the compartment 1b at the upper end of the tube 13. Spray more. At this time, the damper opening/closing control mechanism is operated by electrically interlocking with a signal from the timer or detector or the like or the start of operation of the pulse air supply mechanism 10, and the exhaust duct 6 connected to the compartment 1b is activated. The off-line damper 7b of the outlet duct 6b is closed, and the inlet of the inlet duct 5 into the compartment 1b is closed so that a strong suction action from the exhaust duct 6 side does not act on the compartment 1b. The dust-containing air flow from the duct 5b is stopped. In this state, by intermittently injecting the high-pressure pulsed air into the bag 4, the pulsed air hits the bag 4 strongly from the inside without causing a pressure drop, thereby removing the bug-collected dust. Efficiently brush it off to the outside dirty side B,
It is caused to settle and accumulate at the lower end of the lower hopper 3. Incidentally, the dust accumulated in the lower hopper 3 is removed to the outside in a timely manner. Also, while the bug collection dust is being removed from one of the compartments 1b, other compartments 1b are
a, 1c, 1d, each offline damper 6
a, 6b, 6c, and 6d are kept open, and dust-containing air is sucked and introduced from the introduction duct 5 to continue the filtration and dust collection operation.

Also, when removing the bug collecting dust mentioned above,
By injecting high-pressure pulsed air, the bag 4 is intermittently hit strongly from the inside, but at this time, some of the dust attached to the filter cloth of the bag 4 is blown out to the outside due to the large energy of the pulsed air. Instead, the bugs fly up and scatter inside the bug 4, and float on the clean side A in the compartment 1b. If this remains as it is and the off-line damper 7b is opened to resume dust collection as described later, the floating dust will be sucked into the exhaust duct 6 and come out. Therefore, among the return dampers 16a to 16d, which are all closed during normal dust collection operation, only the return damper 16b of the connecting duct 14b connected to the selected compartment 1b is changed to the closed state of the offline damper 6b. After a short delay, the opening/closing mechanism opens and the return fan 15 is operated. With this, the dust that is partially blown up inside the bug 4 during the dust removal of the bugs in the compartment 1b is drawn out from the clean side A to the return duct 14 by moderate suction, and is sent to the introduction duct 5. Then, other compartments 1a, 1c, 1d which are in dust collection operation together with dust-containing air.
The dust is returned to the dirty side B and collected again.

Therefore, when the regeneration is completed by brushing off the collected dust of the bugs 4 in the compartment 1b, the operation of the backwash pulse air supply mechanism 10 is stopped, and then the return damper 16b is closed by the opening/closing mechanism, and the offline The damper 7b is opened by the damper opening/closing control mechanism. At this time, the off-line damper 7b is not fully opened all at once, but is controlled to be 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 1b is not suddenly increased, but is given a little at first, and the dust-containing air from the introduction duct 5 side is slowly sucked and introduced, thereby immediately after regeneration. While avoiding rapid conduction of dust-containing air to the filter cloth layer of the bag 4 with its openings, and preventing dust from blowing through to the clean side A or penetrating deep into the filter cloth layer, The bug 4
Adhere dust appropriately to the surface of the filter cloth. After preliminary dust collection in this way, the offline damper 7b
Fully open to create normal dust collection condition.

In this way, after bug regeneration and dust collection in one compartment 1b are resumed, 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 performed. resume. 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, it is possible to efficiently blow off the bug-collected dust by jetting the backwash pulse air, and at the same time, when the dust-containing dust is finished being removed, the dust-containing airflow is suddenly conducted to the bag filter cloth layer. It is possible to restart dust collection after avoiding dust, which prevents clogging due to dust blowing through to the exhaust side or biting deep into the filter layer, reducing the amount of dust coming out on the exhaust side, and improving bug regeneration effects. In turn, it helps to save energy and reduce costs by reducing the pressure loss of bugs, and the dust that flies up when dust is removed from the bugs is not discharged outside and can be transferred to other compartments. This is an extremely excellent dust collection method and device that enables effective dust collection.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
The figure is a schematic configuration diagram of the entire apparatus, and FIG. 2 is a time chart of the operation of brushing off the bug-collected dust by an off-line damper and backwash pulse air. 1... Dust collector main body, 1a to 1c... Compartment 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~ 6d... Outlet duct, 7a to 7d... Offline damper, 8... Suction fan, 9... Exhaust pipe, 10... Backwash pulse supply mechanism, 11... Header, 12... Diaphragm valve, 13... Pulse supply tube, 14...
Return duct, 14a to 14d...branch connection duct, 15...return fan, 16...return damper.

Claims (1)

[Scope of Claims] 1. Dust-containing air from a dust source is conducted through an introduction duct to the bag from the dirty side in each of the plurality of compartments of the dust collector main body, and the dust in the air is filtered and collected. The air thus purified is exhausted from the clean side of each compartment to the outside via an exhaust duct by a suction fan, and the dust collected in the bug is returned to the bag at different times at different times for each compartment. In the dust collection method described above, the dust is removed by injecting pulsed air from the upper end side to the bottom of the dust collector body, and the dust collection operation is continued in a compartment other than the compartment where the dust is being removed. When removing bug-collected dust by jetting pulsed air from each compartment of the dust collector, close the off-line damper between the clean side of the compartment and the exhaust duct, and close the off-line damper between the clean side of the compartment. The dust that flies up is sucked out through the return duct and introduced to the dirty side in another compartment, and when the bug-collected dust is removed, the suction of dust from the compartment to the return duct is stopped, and an offline damper is activated. A dust collection method characterized in that the off-line damper is opened slightly to perform preliminary dust collection, and then the off-line damper is fully opened to restart dust collection in the compartment. 2. A dust collector body whose interior is divided into a plurality of compartments and each compartment has a built-in bug that filters and collects dust in the dust-containing air, and a dust source is located on the dirty side of each compartment of the dust collector body. an introduction duct that introduces dust-containing air from the air, an exhaust duct and a suction fan that exhaust air purified by filtering and collecting dust by bugs in each compartment to the outside from the clean side of the compartment; It is equipped with a backwashing pulse air supply mechanism that removes the dust collected in the bag by blowing it off to the lower part of the dust collector body by injecting pulsed air into the bag from the upper end side at different timings for each compartment. In the dust collector, an off-line damper is provided at the connection between the clean side in each compartment of the dust collector body and the exhaust duct, and the dust is sucked out from the clean side in each compartment and conducted to the dust-containing air introduction duct. A return duct with a return fan is installed to separate the return duct and each compartment, and a return damper is installed to individually cut off communication between the return duct and each compartment. A tamper opening/closing control mechanism is provided which closes the off-line damper and opens a return damper, and closes the return damper of the compartment when the bug-collected dust has been removed and keeps the off-line damper slightly open for a predetermined period of time before fully opening it. A dust collector characterized by comprising: