JPH1190141A - Dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically shake off the dust deposited on a bag filter. SOLUTION: When a switching valve is operated, gas does not flow into a dust hopper into which the gas has been flowing, and the gas flows into another dust hopper into which the gas has not been introduced. Consequently, the pressure in the bag filter 49 at the inlet opening 46 corresponding to the dust hopper into which the gas does not flow is lowered, hence the bag filter 49 is rapidly contracted, and the dust depositing on the inner face of the bag filter 49 is shaken off. Meanwhile, the bag filter 49 at the inlet opening 46 corresponding to the dust hopper into which the gas flows is rapidly expanded, the dust depositing on the inner face of the bag filter 49 is shaken off, the gas instantaneously stemmed by the bag filter 49 is introduced between the outer face of a riser cylinder 60 and the inner face of the bag filter 49, and the dust is entrained by the generating current and smoothly discharged into the dust hopper through a gap 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collector for removing dust generated when a granular material such as a synthetic resin raw material is dried or transported by a gas flow.

[0002]

2. Description of the Related Art Conventionally, the following types of dust collectors are known. That is, a dust collecting chamber having an outlet on a wall other than the bottom wall and having at least one inlet opening on the bottom wall, a filter holding frame provided at an edge of the inlet opening and projecting upward, A flexible bag-shaped filter having a bottom portion opened on the filter holding frame, a fixing tool for closely fixing a lower peripheral edge of the bag-shaped filter to an edge of an inlet opening, and an introduction port provided on the bottom wall. Have one
One having two dust hoppers and an on-off valve provided at a dust outlet at the lower end of the dust hopper is known. The dust collector is provided with a vibration generator for applying mechanical vibration to the bag-shaped filter in the dust-collecting chamber as a device for shaking off dust attached to the inner surface of the bag-shaped filter, or on the inner surface of the bag-shaped filter. A cleaning nozzle for ejecting gas is installed in a dust hopper.

[0003]

Disadvantages of the prior art The conventional dust collector has the following disadvantages. That is, the vibration generating device provided in the dust collection chamber has many failures, and when the cleaning air is blown out from the cleaning nozzle, the cleaning air enters the gas circulation path including the dust collector, and the inside of the gas circulation path. There is a drawback that the state of the gas changes and is often undesirable.

[0004]

The present invention employs the following means to solve the above-mentioned drawbacks. The invention according to claim 1 has a dust collecting chamber having an outlet on a wall other than the bottom wall and having at least two inlet openings on the bottom wall, and a bottom portion whose lower peripheral edge is closely fixed to an edge of the inlet opening. An open flexible bag filter, at least two dust hoppers having an inlet provided on the bottom wall in opposition to at least one inlet opening, and a valve for opening and closing the inlet, And an on-off valve provided at a dust outlet at the lower end of the dust hopper.

[0005]

The first aspect of the present invention has the following functions. If the inlet of one dust hopper is closed, the bag-shaped filter at the inlet opening corresponding to the dust hopper is deflated and the dust attached to the inner surface of the bag-shaped filter is shaken off. The dust attached to the bag-shaped filter can be automatically shaken off by a simple operation of closing the mouth without changing the gas state in the gas circulation path including the dust collector. It can be operated continuously.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. The pre-drying hopper dryer 1 has a granular material inlet 2 at the top, and a granular material outlet 3 that can be opened and closed by an on-off valve 4 at a lower portion. The granular material inlet 2 is connected to a granular material storage tank (not shown) or the like. Further, the hopper dryer 1 for preliminary drying has a gas inlet 6 at the body and a gas outlet 7 at the top. A conduit 10 having a gas outlet 9 at the lower end at the gas inlet 6
Is connected.

[0007] A preliminary drying device 13 is connected to connect the gas outlet 7 and the gas inlet 6. The predrying device 13 includes a known cyclone 15 connected to the gas outlet 7 via a conduit 14, and an outside air inlet 1 connected to the cyclone 15 via a gas exchanger 72 and the conduit 14.
7, a gas circulation blower 18 connected to the chamber 16 via a conduit 14, and a heating unit having a heater (not shown) connected to the gas circulation blower 18 via a conduit 14. And the heating chamber 1
9 is connected to the gas inlet 6 via a conduit 14. The opening area of the outside air inlet 17 of the chamber 16 can be adjusted by a shutter (not shown) or the like. A filter (not shown) is housed in the chamber 16 so as to cover the outlet of the chamber 16. A filter (not shown) is provided in the heating chamber 19 so as to cover the outlet of the heating chamber 19.
Is stored.

As shown in FIG. 6, the gas exchanger 72 includes a conduit 73 connected to the outlet of the cyclone 15, an adjusting cylinder 74 which can move up and down and can be fixed at a desired position on the conduit 73. A taper cylinder 76 which is located above the adjusting cylinder 74 and is connected to the conduit 14 on the chamber 16 side so as to form an outside air opening 75 between the adjusting cylinder 74 and a downwardly opened tapered cylinder 76. Have. With such a configuration, a part of the gas discharged from the cyclone 15 can be discharged to the outside air, and a predetermined amount of the outside air can be introduced into the tapered cylinder 76 and the conduit 14 from the outside air opening 75.

The main drying hopper dryer 21 includes:
It has a granular material inlet 22 at the top and a cutting device 24 at the bottom.
The powder material outlet 23 having the following. The granular material inlet 22 is connected to the granular material outlet 3 of the preliminary drying hopper dryer 1. The powder outlet 23 is connected to a hopper such as an injection molding machine (not shown) via a conduit. The granular material in the pre-drying hopper dryer 1 is guided into the main drying hopper dryer 21 by opening the on-off valve 4. The main drying hopper dryer 21 has a gas inlet 26 at the body and a gas outlet 27 at the top. A conduit 30 having a gas outlet 29 at the lower end is connected to the gas inlet 26.

A main drying device 33 having no outside air opening is connected to connect the gas outlet 27 and the gas inlet 26. The main drying device 33 includes a gas outlet 27.
, A dust collector 35 connected to the dust collector 35 via a conduit 34, a gas circulating blower 38 connected to the dust collector 35, and a heater connected to the gas circulating blower 38 via a conduit 34. Heating chamber 39 (not shown)
3 connecting the dust collector 35 and the gas circulation blower 38
4 and a dehumidifier 41 connected in parallel via a conduit 36.

The dust collector 35 has an outlet 45 on a wall other than the bottom wall 44, for example, a side wall, and the bottom wall 44 has at least two outlets.
, Specifically a dust collection chamber 47 having eight inlet openings 46
A filter holding frame 48 provided at the edge of the inlet opening 46 and protruding upward, a flexible filter 49 having a bottom opened loosely over the filter holding frame 48, A fixing device 50 for closely fixing the lower peripheral edge of the filter 49 to an edge of the inlet opening 46, for example, a rising edge 62, and at least one, specifically, four inlet openings 46 provided on the bottom wall 44. In addition, at least two, specifically two dust hoppers 53 having an inlet 52, and each dust hopper 53
And an on-off valve 55 provided at the dust discharge port 54 at the lower end of the opening.

A conduit 34 is connected to each of the inlets 52, and the upstream side of these conduits 34 is connected to each of two outlets of a switching valve 57. One inlet of the switching valve 57 is connected to the main drying line via the conduit 34. Hopper dryer 2
One gas outlet 27 is connected. The switching valve 57
Is such that the inlet 52 of one dust hopper 53 is closed and the inlet 52 of the other dust hopper 53 is opened. The switching valve 57 operates so as to change the state every predetermined time. A rising cylinder 60 is formed via a required number of connecting pieces 59 so as to form a gap 58 between the edge of the entrance opening 46 and the edge.
Is provided on the bottom wall 44, and the upper end of the rising cylinder 60 is narrowed. The fixing device 50 includes a band 63 having an annular shape.
And a fastening / connecting tool 64 having bolts and nuts. The structure of the fixture 50 for fixing the lower peripheral edge of the bag-shaped filter 49 is arbitrary.

Although the filter holding frame 48 is formed by assembling thin rods, it may be formed by a perforated plate made of metal or synthetic resin. The bag-shaped filter 49 is optional such as made of cloth. Below the dust discharge port 54 of the dust hopper 53, a dust box 66 whose upper surface is open faces. The dust box 66 can be connected to and separated from the dust hopper 53 by a known connecting tool (not shown).

The dehumidifying device 41 has a dehumidifier 69 and a gas circulation blower 70. Note that A and B in FIG.
To eliminate the conduit 34 between
Is unnecessary. A filter (not shown) is housed in the heating chamber 39 so as to cover the outlet of the heating chamber 39. The dust collecting chamber 47 has a top wall that can be freely removed for replacement of the bag-shaped filter 49 and the like, and this top wall can be freely connected to and separated from the side peripheral wall in a hermetically sealed state by a known connector (not shown). ing.

[0015]

Next, the operation of the embodiment of the present invention will be described. When the pre-drying hopper drier 1 is empty, a predetermined amount of the granular material is supplied to the pre-drying hopper dryer 1 from a granular material storage tank (not shown) after the on-off valve 4 is closed. Thereafter, preliminary drying is performed. That is, the gas heated in the heating chamber 19 enters the pre-drying hopper dryer 1 via the gas inlet 6 and the conduit 9 and rises through the space between the powders and granules. I do. Then, the ascending gas exits through the gas outlet 7. The wet gas discharged from the gas outlet 7 is
After dust is removed by cyclone 15, heating chamber 1
After being heated in 9, it again enters the pre-drying hopper dryer 1 through the gas inlet 6. A part of the wet gas discharged from the cyclone 15 is supplied to the outside air opening 75.
The outside air having a low humidity is discharged to the outside, and the outside air having a low humidity is introduced into the circulation path through the outside air opening 75 and the outside air intake 17. When the main drying hopper dryer 21 becomes empty, the on-off valve 4 opens, and the pre-dried powder is supplied from the pre-drying hopper dryer 1 to the main drying hopper dryer 21. Hopper dryer for preliminary drying 1
When is empty, the on-off valve 4 closes. Thereafter, main drying is performed. That is, the gas heated in the heating chamber 39 enters the main drying hopper dryer 21 through the gas inlet 26 and the conduit 29 and rises through the space between the granules, during which the granules are dried. I do. The humid gas discharged from the gas outlet 27 is dust-removed by the dust collector 35, dehumidified by the dehumidifier 69, and heated in the heating chamber 39. Go inside the dryer 21.
When the drying is completed, the granular material is discharged from the granular material outlet 23 by the cutting device 24.

The main drying hopper dryer 2
When a predetermined amount of the granular material is discharged from 1, the pre-dried granular material corresponding to the discharged amount is transferred from the predrying hopper dryer 1 to the main drying hopper dryer 2.
1 and discharged from the pre-drying hopper dryer 1 may be supplied to the pre-drying hopper dryer 1 from a powder storage tank (not shown).

In the dust collecting chamber 47, dust adhering to the bag-like filter 49 is shaken off and the dust is discharged from the dust hopper 53 as follows. When the switching valve 57 is switched, the gas stops flowing into the dust hopper 53 where the gas has flowed so far, while the gas flows into the dust hopper 53 where the gas has not flowed so far. As a result, the pressure inside the bag-shaped filter 49 at the inlet opening 46 corresponding to the dust hopper 53 where the gas has stopped flowing in is reduced, and the bag-shaped filter 49 is rapidly withered. The dust adhering to the filter is shaken off, while the bag-shaped filter 49 of the inlet opening 46 corresponding to the dust hopper 53 into which the gas has flowed in is inflated rapidly. The attached dust is shaken off, and the dust is generated by the gas instantaneously blocked by the bag-shaped filter 49 flowing between the outer surface of the rising cylinder 60 and the inner surface of the bag-shaped filter 49. On the dust hopper 53 through the gap 58 smoothly
Is discharged. When a predetermined amount of dust accumulates in the dust hopper 53, the on-off valve 55 is opened and the dust is discharged to the dust box 66.

[0018]

[Modifications and the like] Modifications and the like will be described below. (1) The powders and granules include powders, granules, minute flakes, short fiber pieces and the like. (2) The number of dust hoppers 53 is not limited to two, but may be three or more. Further, in the embodiment, four inlet openings 46 correspond to one dust hopper 53, but it is sufficient that one dust hopper 53 has one inlet opening 46. (3) The dehumidifier 69 may be any device as long as it removes gas moisture. (4) The hopper dryer 1 for preliminary drying is provided at a position away from the hopper dryer 21 for main drying, and the granular material outlet 3 of the hopper dryer 1 for preliminary drying is connected to the granular material of the hopper dryer 21 for main drying via a conduit. Entrance 2
Needless to say, it may be connected to 2. (5) The switching valve 57 is eliminated, the conduits 34 having on-off valves are connected to the respective inlets 52, and the upstream sides of these conduits 34 are connected to connect to the gas outlet 27 of the hopper dryer 21 for main drying. The dust may be shaken off so that the valve is not closed at the same time and is closed at a predetermined time interval for a predetermined short time. When three or more dust hoppers 53 are provided, the switching valve 57
Alternatively, an on-off valve may be used in appropriate combination or without combination. Needless to say, the gas is supplied to at least one dust hopper 53 at any time during the operation of the main drying device 33. (6) Instead of the filter holding frame 48 for holding the bag-shaped filter 49, the upper part of the bag-shaped filter 49 may be hung by means of an elongating / retracting hanging tool such as a spring or a rubber, or a non-elongating cord or the like. It may be. Further, the bag-shaped filter 49 may not be held. (7) The rising cylinder 60 may not be provided.

[0019]

According to the present invention, the following effects can be obtained by the above configuration. According to the first aspect of the present invention, when the inlet of one dust hopper is closed, the bag-shaped filter at the inlet opening corresponding to the dust hopper is deflated, and dust adhering to the inner surface of the bag-shaped filter is shaken. As it is dropped, that is, the dust attached to the bag-shaped filter can be automatically shaken off without changing the state of the gas in the gas circulation path including the dust collector by a simple operation of closing the inlet port. Therefore, the dust collector can be operated continuously for a long time. According to the second aspect of the present invention, when the gas is introduced into the inlet after the dust has been shaken off, a large amount of gas rapidly flows upward through the rising cylinder. The bag-shaped filter is rapidly inflated and the gas instantaneously blocked by the bag-shaped filter flows between the outer surface of the rising cylinder and the inner surface of the bag-shaped filter, and the flow smoothly guides the dust to the dust hopper. I can do it.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a partially crushed dust collector.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is an enlarged sectional view of a portion C in FIG. 1;

[Explanation of symbols]

 35 Dust collector 44 Bottom wall 45 Outlet 46 Inlet opening 47 Dust collection chamber 48 Filter holding frame 49 Bag-shaped filter 50 Fixture 52 Inlet 53 Dust hopper 54 Dust outlet 55 Open / close valve 57 Switching valve

Claims (2)

[Claims] 1. A dust collecting chamber having an outlet on a wall other than the bottom wall and having at least two inlet openings on the bottom wall, and an opening on a bottom portion whose lower peripheral edge is closely fixed to an edge of the inlet opening. Flexible bag-shaped filter and at least one
A dust collector having at least two dust hoppers having inlets provided opposite to the two inlet openings, valves for opening and closing the inlets, and on-off valves provided at dust outlets at the lower end of each dust hopper. . 2. A rising cylinder is provided on a bottom wall via a connecting piece so as to form a gap between the entrance opening and an edge thereof, and an upper end of the rising cylinder is narrowed. The dust collector according to 1.