JPH0446804Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a dust collector, and more specifically, to a structure that reduces the degree of increase in pressure loss in a bag filter type dust collector of the air jet type. .

[Background of the idea]

As shown in FIG. 4, for example, a conventionally known bag filter type dust collector divides the inside of the device outer casing 1 into upper and downstream air chambers 4 and 5 by means of a shielding wall 2 and bag filters 3a, 3b, and 3c. The dust-containing airflow introduced into the upstream air chamber 4 in the outer casing 1 from the upstream side is guided to the downstream air chamber 5 through the bag filter 3, the dust is filtered through the bag filter 3, and excess air is removed by a suction blower (not shown). ) to the exhaust side, and each bag filter 3a,
3b, 3c are provided with pipes 6, 6, . . . having nozzles that apply an air jet to blow off dust attached to the cloth. In addition, 7 is an introduction pipe for dust-containing airflow, 8 is a discharge pipe for excess air,
Reference numeral 9 represents a solenoid valve for supplying air jet, and reference numeral 10 represents a rotary valve for discharging dust sifted from the bag filter to the outside of the housing. In such a bag filter type dust collector, in order to reduce as much as possible the problem of gradually increasing pressure loss due to clogging with dust, it is essential to blow off the dust attached to the cloth by the action of the air jet described above. It is said that
For example, three bug filters 3a as shown in FIG.
In the dust collectors 3b and 3c, as shown in the time chart of FIG. 5, the air jet is applied intermittently by shifting the phase between the bag filters. By the way, considering the state in which an air jet acts in such a bag filter type dust collector, for example, when an air jet acts on the central bag filter 3b in FIG. The dust falls due to its own weight, but since the airflow from the upstream air chamber 4 to the downstream air chamber 5 continues to flow, firstly, the acting force of the jet air is reduced, and secondly, the dust once separated from the cloth is It has been pointed out that the dust tends to adhere to the original cloth again, making it difficult to remove dust from the cloth bag filter, that is, to obtain a sufficient cloth cleaning effect.

Further, depending on the distance between adjacent bag filters, there is a problem in that dust brushed off from one bag filter may adhere to the neighboring bag filter 3a or 3c.

[Purpose of invention]

The present invention has been developed in view of the above points, and its purpose is to brush off the dust adhering to the bag filter as efficiently as possible, and to increase the collection rate of the dust released from the bag filter. A dust collector is provided.

Another purpose of the present invention is to efficiently separate and collect the dust from the bag filter, thereby extending the continuous operation time, extending the replacement interval of the bag filter, and reducing costs. It is in.

[Summary of the idea]

The feature of the dust collector according to the present invention, which was made to achieve the above-mentioned object, is to pass dust-containing airflow from the outside to the inside of a plurality of cylindrical bag filters with open tops arranged in a row to remove dust. A dust collector which filters the dust and is provided with an air jet nozzle facing the upper end opening of each bag filter to blow air into the bag filter, and blows an intermittent air jet for removing dust at staggered times for each bag filter. , a shielding wall extending between and shielding each of the bag filters arranged in a row; and a shielding wall that blocks the airflow passing through each bag filter and flowing upward from the upper end opening from the airflow passing through the other bag filters. A path separated by a wall and a merging path in which these independent paths are merged on the downstream side of the air flow are provided, and each is provided so that the air flow from each of these independent paths to the merging path can be blocked. a normally open type shutoff valve, and a normally closed type atmosphere introduction valve that is opened so as to introduce the atmosphere into the cylinder of the shut off bag filter in synchronization with the path cutoff by these shutoff valves; The structure includes a control means for closing the normally open shutoff valve and opening the normally closed atmosphere inlet valve in conjunction with the air jet blowing to the corresponding bag filter.

The independent path for each bag filter provided in the configuration of the present invention is realized by making the downstream air chamber an independent air chamber that corresponds one-to-one to each bag filter. It becomes possible to temporarily stop the flow of dust-containing air that is constantly passed through the filter, and effectively prevent the dust that has been sieved off from re-adhering. Furthermore, inside the upstream air chamber facing the bag filter,
By blocking each bag filter with a shielding wall, there is an advantage that it is possible to effectively prevent dust sifted from one bag filter from adhering to an adjacent bag filter.

[Example of idea]

The present invention will be described below based on embodiments shown in the drawings.

The embodiment shown in FIG. 1 is different from the conventional example shown in FIG. The air chambers 5a, 5b, 5c, and each independent downstream air chamber 5a,
A switching valve device 12 that switches and connects 5b and 5c between the exhaust pipe 7 side that sucks and discharges excess air and the atmosphere.
a, 12b, and 12c (therefore, this switching valve device has the two functions of a path cutoff valve and an atmospheric air introduction valve), and the upstream air chamber 4 has respective bag filters 3a, 3b, 3c
The difference is that the state of airflow around each bag filter is made independent by a shielding wall 13 between the bag filters, and the other configurations are generally the same as the case of FIG. In other words, 1 is the outer casing of the device, 2 is a shielding wall, and 6 is a pipe 7 having an air jet nozzle.
8 is the introduction pipe for dust-containing air flow, 8 is the discharge pipe for excess air, 9 is
is a solenoid valve, and 10 is a rotary valve. Second
The figure shows the action timing of the air jet provided in the dust collector with the above structure and the switching valve device 12.
This is a time chart showing an example of the operation timing of a to 12c in relation to each other. Each switching valve device communicates the downstream air chamber with the exhaust pipe 8 side when opened, and communicates the downstream air chamber with the atmosphere when closed. It's becoming like that. Here, the reason why the downstream air chamber is communicated with the atmosphere is that the air sucked in by the ventilate effect during air jet action is introduced from the atmosphere, so that sufficient cleaning air is provided, and this allows the air jet to filter out the bag filter. This is to make the dust removal effect even more effective.

It is preferable that the switching of the switching valve device from the normally open state to the closed state is performed slightly earlier than when the air jet is activated, and that the normally open state is returned to after a certain period of time t ₂ continues after the air jet is activated. It is best to do this by temporarily stopping the air flow when dust is being removed during the air jet action relative to a steady state, and ensuring a time _t3 for the dust to fall into the pool at the bottom. The timing of opening → closing → opening of these switching valve devices is appropriately selected depending on the design of the dust collector, etc., and its operation is controlled by a control device (not shown).

Considering the situation in which the air jet is currently being applied to the bag filter 12b in the center of FIG. communicated with the atmosphere. Therefore, the steady airflow that was flowing from the upstream air chamber 4 to the downstream air chamber 5b with respect to the bag filter 3b is stopped, and when the air jet acts in this state, the bag filter 3
The dust adhering to b is brushed off. Due to the presence of the shielding wall 13, this dust is prevented from adhering to the adjacent bag filters 3a and 3c, and due to the stoppage of the steady airflow, the dust is removed from the bag filter 3.
Since there is no chance of re-adhesion to the rotary valve 10, the dust that has been brushed off settles without any problem, is deposited in the reservoir 14, and is discharged to the outside from the rotary valve 10. By sequentially performing such dust removal on each bag filter with a temporal phase shift, the bag filters can be effectively cleaned.

Figure 3 shows the changes in filter pressure loss measured when a series of continuous dust removal operations were performed under the same conditions for the embodiment of the present invention shown in Figure 1 and the conventional example shown in Figure 4. The results show that the degree of clogging of the so-called bag filter is reduced to about 1/2 compared to the conventional example.

[Effect of idea]

As described above, in the bag filter type dust collector of the present invention, sufficient cleaning air is provided by removing the dust adhering to the bag filter by the air jet action and introducing atmospheric air by the Benliulli effect during the air jet action. Combined with this effect, the dust removal effect due to the air jet effect is performed even more effectively, and the degree of increase in pressure loss over time is greatly reduced, thus reducing the need for periodic filter replacement. Because the frequency is reduced, the continuous operation of the dust collector and the continuous operation rate of equipment that requires dust collection are improved, and the wear and tear of the bag filters used is also reduced, resulting in cost reduction. The profits are huge.

[Brief explanation of the drawing]

FIGS. 1A, 1B, and 1C show an outline of a dust collector that is an embodiment of the present invention, in which A is a longitudinal cross-sectional view, B is a side cross-sectional view, and C is a plan view. FIG. 2 is a time chart for explaining the operation of the apparatus shown in FIG. 1, and FIG. 3 is a diagram illustrating the increase in pressure loss of the bag filter in comparison with a conventional example. FIGS. 4A, 4B, and 4C are diagrams showing the conventional apparatus corresponding to FIGS. 1A, 2B, and 1C, and FIG. 5 is a time chart for explaining the operation of the apparatus shown in FIG. 1...outer casing, 2...shielding wall, 3a, 3b, 3c...
...Bag filter, 4...Upstream air chamber, 5, 5a, 5
b, 5c...downstream air chamber, 6...nozzle, 7...introduction pipe, 8...discharge pipe, 9...ventilate, 10
...Rotary valve, 12...Switching valve device, 1
3...Blocking wall, 14...Dust pool.

Claims (1)

[Claims for Utility Model Registration] Dust-containing airflow is passed from the outside to the inside of a plurality of cylindrical bag filters with an opening at the top arranged in a row to filter dust, and the bag filter is placed opposite to the opening at the top of each bag filter. In a dust collector that is provided with an air jet nozzle that blows air inside the dust collector, and blows an intermittent air jet for removing dust at different times for each bag filter, the dust collector is installed between each of the bag filters arranged in a row. The airflow that has passed through each bag filter and has flowed upward from the upper end opening is made independent from the airflow that has passed through other bag filters by the shielding wall, and these independent paths are used for air flow. In addition to providing a merging path that merges on the downstream side of the A normally-closed atmosphere inlet valve is provided, which is opened in synchronization with the shutoff so that the atmosphere can be introduced into the cylinder of the shut-off bag filter, and the normally-opened shutoff valve is closed and the normally-closed atmosphere inlet valve is opened. 1. A dust collector comprising a control means for opening a valve in conjunction with the above-mentioned air jet to a corresponding bag filter.