Dust collector

Abstract

It reduces energy consumption compared to conventional technologies. [Solution] The dust collector includes a first fan for passing introduced dust-laden air through a filter and discharging it to the outside, and a second fan for supplying gas to the filter in the opposite direction to the direction of passage of the dust-laden air to remove dust adhering to the filter. The second fan operates while the first fan is operating, and when gas is not supplied to the filter, it is driven with less driving force than when gas is supplied. Since the second fan is driven with less driving force when gas is not supplied to the filter than when gas is supplied, energy consumption can be reduced compared to conventional technology in which the filter is driven with the same driving force as when gas is supplied, even when gas is not supplied.

Description

Technical Field

[0001] The technology of the present disclosure relates to a dust collector.

Background Art

[0002] Patent Document 1 discloses a dust collector including a dust collection chamber to which dust-containing air from a furnace is supplied, a plurality of rooms each provided with a plurality of filter cloths in the dust collection chamber, a filtration fan for attracting the dust-containing air so as to discharge it to the outside through each filter cloth of the dust collection chamber and each room, and a reverse washing fan for sequentially supplying air to each room in a direction opposite to the attracting direction in order to drop the dust attached to each filter cloth of each room.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the dust collector of Patent Document 1, the time for supplying air to each room by the reverse washing fan is a predetermined short time. However, the reverse washing fan operates continuously while the filtration fan is operating. That is, the reverse washing fan operates not to drop the dust attached to the filter cloth except for the above-mentioned predetermined short time, but simply operates. Therefore, the energy consumption of the reverse washing fan is unnecessarily high.

[0005] The technology of the present disclosure aims to provide a dust collector capable of reducing the energy consumption compared to the prior art.

Means for Solving the Problems

[0006] To achieve the above objective, a first aspect of the technology of the present disclosure is a dust collector comprising: a first fan for discharging introduced dust-laden air through a filter to the outside; and a second fan for supplying gas to the filter in the opposite direction to the direction of passage of the dust-laden air in order to remove dust adhering to the filter, wherein the second fan operates while the first fan is operating, and is driven with less driving force when gas is not supplied to the filter than when gas is supplied. [Effects of the Invention]

[0007] In a first aspect of the technology of this disclosure, the second fan is driven with less driving force when no gas is supplied to the filter than when gas is supplied, thus reducing energy consumption compared to the conventional technology in which the fan is driven with the same driving force as when gas is supplied, even when no gas is supplied to the filter. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of an example of a dust collector 10 according to the first embodiment. [Figure 2] Figure 2 is a block diagram of an example of the electrical system of the dust collector 10. [Figure 3] Figure 3 is graph G1, which shows an example of the relationship between the rotational speed V1 of the filtration fan motor 46 and the supply speed of dust-containing air. [Figure 4] Figure 4 is graph G2, which shows an example of the relationship between the rotational speed V2 of the backwash fan motor 42 and the rotational speed V1 of the filtration fan motor 46. [Figure 5] Figure 5 is graph G3, which shows an example of the relationship between the change in rotational speed ΔV2 of the backwash fan motor 42 and the pressure difference (differential pressure) before and after the dust-containing air passes through filters 16F11 to 16F32. [Figure 6] Figure 6 shows an example of the processing performed by each functional unit of the CPU 52 (damper control unit 52A, input unit 52B, motor drive unit 52C, variable processing unit 52D, and determination unit 52E). [Figure 7]Figure 7 is a flowchart showing an example of a dust collection program 56P executed by the CPU 52. [Figure 8] Figure 8 is a schematic diagram of an example of a dust collector 10 according to the second embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the technology of this disclosure will be described below with reference to the drawings.

[0010] [First Embodiment] (composition) Figure 1 is a schematic diagram of an example of a dust collector 10 according to the first embodiment. For the sake of explanation, the upper side of Figure 1 will be referred to as "upper (or upward)" and the lower side as "lower (or downward)".

[0011] As shown in Figure 1, the dust collector 10 comprises a chamber to be introduced 12 and multiple chambers.

[0012] Dust-laden air from the electric furnace 100 (see also Figure 2) is cooled by a cooling device (not shown) and then introduced into the introduction chamber 12 via the introduction pipe 11. The introduction chamber 12 is provided with an exhaust section (not shown) at its lower part for discharging dust.

[0013] The electric furnace 100 is not the only option; for example, it could be an incinerator, steelmaking electric furnace, sintering furnace, or crushing equipment installed in an industrial facility such as a processing facility for industrial waste or household waste, or an iron and steel production facility.

[0014] Each of the multiple chambers is equipped with at least one filter (e.g., a filter cloth). Figure 1 shows three chambers, specifically the first chamber 14R1 to the third chamber 14R3. The first chamber 14R1 is equipped with two filters 16F11 and 16F12. The second chamber 14R2 is equipped with two filters 16F21 and 16F22. The third chamber 14R3 is equipped with two filters 16F31 and 36F12. Note that the number of chambers and the number of filters in each chamber are not limited to these.

[0015] Above the first chamber 14R1, there are provided a first filtration pipe 18T1 provided with a first filtration damper (i.e., a flow control valve) 32A1 and a first backwash pipe 24H1 provided with a first backwash damper 34A1.

[0016] Above the second chamber 14R2, there are provided a second filtration pipe 18T2 provided with a second filtration damper 32A2 and a second backwash pipe 24H2 provided with a second backwash damper 34A2.

[0017] Above the third chamber 14R3, there are provided a third filtration pipe 18T3 provided with a third filtration damper 32A3 and a third backwash pipe 24H3 provided with a third backwash damper 34A3.

[0018] One end of each of the first filtration pipes 18T1 to 18T3 is connected to the first chamber 14R1, and the other end is connected to the induction pipe 20.

[0019] The induction pipe 20 is connected to a filtration fan 44 for discharging the dust-containing air introduced into the introduction chamber 12 to the outside through the discharge pipe 22 after passing through each of the filters 16F11 to 16F32 in each of the chambers 14R1 to 14R3. The filtration fan 44 includes a filtration fan motor 46. The filtration fan 44 is an example of the "first fan" of the technology of the present disclosure.

[0020] One end of each of the first backwash pipes 24H1 to 24H3 is connected to each of the first filtration pipes 18T1 to 18T3, and the other end is connected to the backwash pipe 26. The backwash pipe 26 is connected to the air discharge end of the backwash fan 40. The backwash fan 40 is a fan for supplying a gas (e.g., air) for removing the dust adhering to each of the filters 16F11 to 16F32 to each of the filters 16F11 to 16F32 in a direction opposite to the passing direction of the dust-containing air.

[0021] Backwashing refers to supplying a gas to each filter 16F11-16F32 in the opposite direction to the direction of passage of the dust-laden air, in order to remove the dust adhering to each filter 16F11-16F32.

[0022] The air intake end of the backwash fan 40 is connected to the induction pipe 20 via an introduction pipe 28. In this way, the cleaned air supplied to the induction pipe 20 via filters 16F11 to 16F32 is taken in by the backwash fan 40 via the introduction pipe 28, and the taken-in cleaned air is supplied to each of the filters 16F11 to 16F32. The backwash fan 40 is equipped with a backwash fan motor 42. As will be described in detail later, the backwash fan 40 operates when the filtration fan 44 is in operation, and when gas is not supplied to each of the filters 16F11 to 16F32, it is driven with a smaller driving force than when gas is supplied, specifically, it stops. The backwash fan is an example of the "second fan" of the technology of this disclosure.

[0023] The dust collector 10 is equipped with a differential pressure sensor 48. One end of the differential pressure sensor 48 is connected to the inlet pipe 11, and the other end is connected to the induction pipe 20. The differential pressure sensor 48 is a sensor that detects the difference in pressure (differential pressure) before and after the dust-containing air passes through the filters 16F11 to 16F32. Specifically, the differential pressure sensor 48 takes in the pressure of the dust-containing air in the inlet pipe 11 from one end and the pressure of the cleaned air in the induction pipe 20 after it has passed through each filter 16F11 to 16F32 from the other end. The differential pressure sensor 48 detects the difference (differential pressure) between these pressures. The differential pressure detected by the differential pressure sensor 48 indicates the degree to which dust is easily removed from each filter 16F11 to 16F32.

[0024] The degree to which dust easily falls from each filter 16F11 to 16F32 is not limited to the differential pressure detected by the differential pressure sensor 48. For example, it may be the type of dust (e.g., type according to particle size) from the information obtained from the electric furnace 100, or the weight of the dust accumulated in the introduction chamber 12, obtained from the weight sensor installed in the introduction chamber 12.

[0025] Figure 2 is a block diagram of an example of the electrical system of a dust collector 10. As shown in Figure 2, the dust collector 10 includes a computer 50. The computer 50 includes a CPU 52, RAM 54, NVM 56, and input / output (I / O) ports 58. The CPU 52, RAM 54, NVM 56, and input / output (I / O) ports 58 are connected to each other via a bus 60 so that they can communicate with one another.

[0026] The input / output (I / O) port 58 is connected to the first to third filtration dampers 32A1 to 32A3, the electric furnace 100, the differential pressure sensor 48, the backwash fan motor 42, the filtration fan motor 46, and the first to third backwash dampers 34A1 to 34A3.

[0027] RAM54 is memory that temporarily stores information and is used as work memory by the CPU52. Examples of RAM54 include DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory).

[0028] The NVM (Non-volatile memory) 56 is a non-temporary storage medium, and the dust collection program 56P (see Figure 7) is stored in the NVM 56.

[0029] The functional unit of the CPU 52 includes a damper control unit 52A, a intake unit 52B, a motor drive unit 52C, a variable processing unit 52D, and a decision unit 52E. The CPU 52 reads the dust collection processing program 56P from the NVM 56 and performs dust collection processing by executing the read dust collection processing program 56P on the RAM 54. The CPU 52 functions as the damper control unit 52A, intake unit 52B, motor drive unit 52C, variable processing unit 52D, and decision unit 52E according to the dust collection processing program 56P executed on the RAM 506.

[0030] Figure 3 is graph G1, which shows an example of the relationship between the rotational speed V1 (i.e., driving force) of the filtration fan motor 46 and the supply speed of dust-laden air. As the supply speed of dust-laden air increases, the rotational speed V1 of the filtration fan motor 46 also increases. This is because increasing the rotational speed V1 of the filtration fan motor 46 in accordance with the increasing supply speed of dust-laden air allows for appropriate cleaning of the dust-laden air according to the amount of dust-laden air supplied.

[0031] Figure 4 is graph G2, which shows an example of the relationship between the rotational speed V2 (i.e., driving force) of the backwash fan motor 42 and the rotational speed V1 of the filtration fan motor 46. As the rotational speed V1 of the filtration fan motor 46 increases, the rotational speed V2 of the backwash fan motor 42 also increases. As the rotational speed V1 of the filtration fan motor 46 increases, the amount of dust-laden air introduced into the intake chamber 12 increases, and the amount of dust adhering to the filters 16F11 to 16F32 increases. When the amount of dust adhering to the filters 16F11 to 16F32 increases, it becomes more difficult for the dust to fall off the filters 16F11 to 16F32. Therefore, as it becomes more difficult for dust to fall off the filters 16F11 to 16F32, increasing the rotational speed V2 of the backwash fan motor 42 makes it easier for the dust adhering to the filters 16F11 to 16F32 to fall off.

[0032] As described above, the filtration fan 44 draws cleaned air from each of the first to third chambers 14R1 to 14R3 into the induction pipe 20 (see Figure 1). The air intake end of the backwash fan 40 is connected to the induction pipe 20 via the introduction pipe 28. Therefore, unless the rotational speed of the backwash fan motor 42 is increased in accordance with the rotational speed of the filtration fan motor 46, the backwash fan 40 cannot take in the cleaned air drawn into the induction pipe 20. Thus, in this embodiment, the rotational speed of the backwash fan motor 42 is increased in accordance with the rotational speed of the filtration fan motor 46.

[0033] Figure 5 is graph G3, which shows an example of the relationship between the change in rotational speed ΔV2 of the backwash fan motor 42 and the pressure difference (differential pressure) before and after the dust-containing air passes through filters 16F11 to 16F32. As the differential pressure becomes larger than a predetermined reference differential pressure P, the change in ΔV2 increases positively. This allows the rotational speed of the backwash fan motor 42 to be increased. As the differential pressure becomes smaller than the differential pressure P, the change in ΔV2 increases negatively. This allows the rotational speed of the backwash fan motor 42 to be decreased.

[0034] The graphs G1 to G3 described above are stored in NVM56 as a data table. Note that NVM56 is not limited to storing graphs G1 to G3 as a data table; they may also be stored as a map or a relational expression.

[0035] Figure 6 shows an example of the processing performed by each functional unit of the CPU 52 (damper control unit 52A, input unit 52B, motor drive unit 52C, variable processing unit 52D, and determination unit 52E).

[0036] When cleaning dust-laden air, the damper control unit 52A opens each of the first filtration dampers 32A1 to the third filtration dampers 32A3 and closes each of the first backwash dampers 34A1 to the third backwash dampers 34A3. When backwashing each chamber, the damper control unit 52A closes each of the first filtration dampers 32A1 to the third filtration dampers 32A3 and opens each of the first backwash dampers 34A1 to the third backwash dampers 34A3 for each chamber.

[0037] The intake unit 52B takes in the supply rate of dust-containing air from the electric furnace 100 and the differential pressure before and after filtration from the differential pressure sensor 48.

[0038] When cleaning dusty air, the motor drive unit 52C drives the filtration fan motor 46 based on the supply rate of dusty air from the electric furnace 100. When backwashing each chamber, the motor drive unit 52C drives the backwash fan motor 42 based on the filtration fan motor 46 and the differential pressure.

[0039] The variable processing unit 52D identifies each room so that it can perform backwashing for each room.

[0040] The determination unit 52E determines whether or not the dust adhering to each filter 16F11 to 16F32 in all rooms (i.e., the first room 14R1 to the third room 14R3) has been removed. If the determination unit 52E determines that the dust adhering to each filter 16F11 to 16F32 in all rooms has been removed, the motor drive unit 52C stops the backwash fan motor 42.

[0041] (action) Figure 7 is a flowchart showing an example of a dust collection program 56P executed by the CPU 52. The dust collection program 56P starts when a start button (not shown) is operated. By executing the dust collection program 56P, the CPU 52 performs the dust collection process and the dust collection method.

[0042] In step 102, the damper control unit 52A opens each of the first filtration dampers 32A1 to the third filtration damper 32A3 and closes each of the first backwash dampers 34A1 to the third backwash damper 34A3.

[0043] In step 104, the intake unit 52B takes in dust-laden air from the electric furnace 100.

[0044] In step 106, the intake unit 52B receives the differential pressure before and after filtration from the differential pressure sensor 48. Alternatively, instead of the differential pressure as described above, the type of dust (for example, a type corresponding to the particle size) from the information obtained from the electric furnace 100, or the weight of the dust accumulated in the intake chamber 12, obtained from a weight sensor installed in the intake chamber 12, may also be used.

[0045] In step 108, the motor drive unit 52C drives the filtration fan motor 46 and drives the backwash fan motor 42. The motor drive unit 52C controls the backwash fan motor 42 so that its driving force (rotational speed V2) is adjusted based on the driving force (rotational speed V1) of the filtration fan motor 46.

[0046] Specifically, the motor drive unit 52C extracts the rotational speed V1 of the filtration fan motor 46 corresponding to the supply speed K of dust-containing air from the electric furnace 100 from the data table of graph G1 (see Figure 3), which shows the relationship between the rotational speed V1 of the filtration fan motor 46 and the supply speed of dust-containing air, and drives the filtration fan motor 46 to rotate at the extracted rotational speed V1k.

[0047] As described above, the first to third filtration dampers 32A1 to 32A3 are open, and the first to third backwash dampers 34A1 to 34A3 are closed. Therefore, when the filtration fan motor 46 is driven, the dust-laden air introduced from the electric furnace 100 into the chamber 12 via the introduction pipe 11 passes through the filters 16F11 to 16F32 in the first to third chambers 14R1 to 34R3. The purified air is then discharged to the outside via the first to third filtration pipes 18T1 to 38T3, the induction pipe 20, and the discharge pipe 22.

[0048] The motor drive unit 52C extracts the rotational speed V2k of the backwash fan motor 42, which corresponds to the rotational speed V1k of the filtration fan motor 46, from the data table of graph G2 (see Figure 4), which shows the relationship between the rotational speed V2 of the backwash fan motor 42 and the rotational speed V1 of the filtration fan motor 46. The motor drive unit 52C also extracts the change in rotational speed ΔV2p0 of the backwash fan motor 42, which corresponds to the acquired differential pressure P0, from the data table of graph G3 (see Figure 5), which shows the relationship between the change in rotational speed ΔV2 of the backwash fan motor 42 and the pressure difference (differential pressure) before and after the dust-containing air passes through filters 16F11~16F32.

[0049] The motor drive unit 52C calculates the rotational speed V2kp0 of the backwash fan motor 42 from the rotational speed V2k and the change amount ΔV2p0 (V2kp0 = V2k + ΔV2p0).

[0050] The motor drive unit 52C drives the backwash fan motor 42 so that it rotates at a rotational speed V2kp0.

[0051] In step 110, the variable processing unit 52D initializes the variable r, which identifies the room, to 0 (r←0). Note that r=1, 2, and 3 identify the first room 14R1, the second room 14R2, and the third room 14R3.

[0052] In step 112, the variable processing unit 52D increments the variable r by 1 (r ← r + 1).

[0053] In step 114, the damper control unit 52A closes the filtration damper for room r, identified by the variable r. In step 116, the damper control unit 52A opens the backwash damper for room r.

[0054] For example, when the variable r=1, the first filtration damper 32A1 in the first chamber 14R1 is closed and the first backwash damper 34A1 is opened. As the backwash fan motor 42 is driven as described above, gas for removing dust adhering to the filters 16F11 and 16F12 of the first chamber 14R1 is supplied to each filter 16F11 and 16F12 in the opposite direction to the direction in which dusty air passes through each filter 16F11 and 16F12 (backwashing). This makes it possible to remove dust adhering to the filters 16F11 and 16F12 of the first chamber 14R1.

[0055] In step 118, the determination unit 52E determines whether the backwash time has elapsed since the backwash damper for room r was opened. If it is not determined that the backwash time has elapsed, the determination is repeated until it is determined that the backwash time has elapsed. If it is determined that the backwash time has elapsed, the dust collection process proceeds to step 120. The backwash time is a predetermined time during which dust attached to the filter of room r is expected to fall off, for example, 1 minute. The backwash time is not limited to 1 minute, and may be 1 minute 30 seconds, 2 minutes, etc.

[0056] In step 120, the damper control unit 52A opens the filtration damper for room r. In step 122, the damper control unit 52A closes the backwash damper for room r. This allows dusty air to pass through each filter in room r.

[0057] In step 124, the determination unit 52E determines whether the dust attached to each filter 16F11 to 16F32 in all rooms (i.e., the first room 14R1 to the third room 14R3) has been removed by determining whether the variable r is equal to the total number of rooms R0 (r=R0).

[0058] If the variable r is not determined to be equal to the total number of rooms R0, it means there are still filters in rooms where dust has not yet been collected, so the dust collection process returns to step 112 and the above process (steps 112-124) is repeated.

[0059] If the variable r is determined to be equal to the total number of rooms R0, it can be determined that the dust attached to each filter 16F11 to 16F32 in all rooms (i.e., the first room 14R1 to the third room 14R3) has been removed. In this case, the dust collection process proceeds to step 126.

[0060] In step 126, the motor drive unit 52C stops the backwash fan motor 42. The motor drive unit 52C is not limited to stopping the backwash fan motor 42; it may also drive the backwash fan motor 42 at a non-zero speed that is slower than the rotational speed V2kp0.

[0061] In step 128, the determination unit 52E determines whether the dust collection process has ended by determining whether or not an exit button (not shown) has been operated. If it is determined that the dust collection process has not ended, the dust collection process proceeds to step 130.

[0062] In step 130, the determination unit 52E determines whether a predetermined time has elapsed since the backwash fan motor 42 was stopped. If it is determined that the predetermined time has not elapsed, the determination is repeated until it is determined that the predetermined time has elapsed.

[0063] If it is determined that the predetermined time has elapsed, the dust collection process returns to step 104 and the above process (steps 104-128, 130) is repeated.

[0064] The predetermined time is, for example, 57 minutes. As a result, every 60 minutes, each filter 16F11 to 16F32 in the first chamber 14R1 to the third chamber 14R3 is backwashed for 1 minute (backwash time). As described above, the backwash fan motor 42 is stopped in step 126. Therefore, no power is supplied to the backwash fan motor 42 during the predetermined time.

[0065] If the dust collection process is deemed complete in step 128, the process proceeds to step 132.

[0066] In step 132, the motor drive unit 52C stops the filtration fan motor 46. When the process in step 132 is completed, the execution of the dust collection program 56P (dust collection process and dust collection method) is completed.

[0067] (effect) When gas is not supplied to each filter 16F11 to 16F32, the backwash fan motor 42 is driven with less force than when gas is supplied, specifically, it stops. Therefore, this embodiment can reduce energy consumption compared to conventional technology, which drives the backwash fan motor with the same force as when gas is supplied, even when gas is not supplied to each filter 16F11 to 16F32.

[0068] By the way, the ease with which dust particles attached to each filter 16F11~16F32 fall off changes depending on the driving force of the filtration fan motor 46 (for example, if the driving force of the filtration fan motor 46 increases, the pressure of dust adsorption onto the filter increases, making it more difficult for the dust to fall off the filter). Therefore, the backwash fan motor 42 adjusts its driving force based on the driving force of the filtration fan motor 46 (for example, if the driving force of the filtration fan motor 46 is high, the backwash fan motor 42 adjusts its driving force). (The driving force of the fan motor 42 is also increased), and the backwash fan motor 42 can be driven according to how easily the dust falls. Therefore, in this embodiment, when the dust falls easily (i.e., when the driving force of the filtration fan motor 46 is small), the backwash fan motor 42 is driven with a smaller driving force, so energy consumption can be reduced.

[0069] [Second Embodiment] A second embodiment will now be described. The configuration and operation of the second embodiment are substantially the same as those of the first embodiment, so only the main differences will be described.

[0070] Figure 8 is a schematic diagram of an example of a dust collector 10 according to the second embodiment. In the backwash fan 40 of the first embodiment described above (see Figure 1), washed air is drawn in from the induction pipe 20 via the inlet pipe 28.

[0071] In contrast, in the dust collector 10H of the second embodiment (see Figure 8), the backwash fan 40 receives cleaned air from the discharge pipe 22 via the inlet pipe 28H.

[0072] In the second embodiment, the relationship between the rotational speed V2 of the backwash fan motor 42 and the rotational speed V1 of the filtration fan motor 46 differs from that of the first embodiment, with the rotational speed V1 of the filtration fan motor 46 increasing and the rotational speed V2 of the backwash fan motor 42 decreasing.

[0073] In the first embodiment, the air intake end of the backwash fan 40 is connected to the induction pipe 20 via the introduction pipe 28. Therefore, unless the rotational speed of the backwash fan motor 42 is increased in accordance with the rotational speed of the filtration fan motor 46, the backwash fan 40 cannot take in the cleaned air induced in the induction pipe 20. In contrast, in the second embodiment, the backwash fan 40 receives cleaned air from the discharge pipe 22 via the inlet pipe 28H along the direction of air travel. Therefore, as the rotational speed of the filtration fan motor 46 increases, more cleaned air is drawn into the backwash fan 40 from the discharge pipe 22. Accordingly, in the second embodiment, as the rotational speed V1 of the filtration fan motor 46 increases, the rotational speed V2 of the backwash fan motor 42 is reduced. This makes it possible to further reduce energy consumption.

[0074] In the first embodiment (see Figure 1), one end is connected to the inlet pipe 11 and the other end is connected to the induction pipe 20, and a differential pressure sensor 48 is provided to detect the difference in pressure (differential pressure) before and after the dust-containing air passes through the filters 16F11 to 16F32.

[0075] In contrast, the second embodiment (see Figure 8) differs in that it is equipped with differential pressure sensors 48H1 to 48H3 that detect the difference (differential pressure) between the pressure of the dust-containing air (inlet pipe 11) introduced into the chamber 12 and the pressure of the air after filters 16F11 to 16F32 in each of the first to third chambers 14R1 to 14R3.

[0076] The differential pressure detected by differential pressure sensors 48H1 to 48H3 indicates the degree to which dust easily falls through the filters installed in the room.

[0077] In the second embodiment, when backwashing is performed in each of the first to third rooms 14R1 to 14R3, the differential pressure corresponding to each room is taken in, the change in the rotational speed of the backwash fan motor 42 is extracted from the data table of graph G3 shown in Figure 5, and the rotational speed V2 of the backwash fan motor 42 is adjusted for each room.

[0078] In this way, the backwash fan motor 42 is driven in each room according to the degree to which dust easily falls from the filter installed in that room, so the backwash fan motor 42 can be driven more precisely in each room.

[0079] [Note] Based on the above disclosures, the following addendum is proposed.

[0080] (Note 1) A first fan is used to pass the introduced dust-laden air through a filter and expel it to the outside. A second fan for supplying a gas to the filter in the opposite direction to the direction of passage of the dust-containing air, for removing dust adhering to the filter, A dust collector equipped with, The second fan operates while the first fan is operating, and when no gas is supplied to the filter, it is driven with a smaller driving force than when gas is supplied. Dust collector.

[0081] Specifically, the dust collector includes a control unit that controls the second fan so that it operates when the first fan is running, and when no gas is supplied to the filter, it operates with less driving force than when gas is supplied.

[0082] The motor drive unit 52C is an example of a "control unit" in the technology of this disclosure.

[0083] According to the invention described in Appendix 1, when the second fan is not supplied with gas to the filter, it is driven with a smaller driving force than when gas is supplied. Therefore, energy consumption can be reduced compared to the conventional technology, which drives the filter with the same driving force as when gas is supplied, even when gas is not supplied.

[0084] (Note 2) The second fan adjusts its driving force based on the driving force of the first fan. The dust collector described in Appendix 1.

[0085] As described above, the control unit controls the second fan so that its driving force is adjusted based on the driving force of the first fan.

[0086] According to the invention described in Appendix 2, the ease with which dust adheres to the filter falls changes depending on the driving force of the first fan. Therefore, by adjusting the driving force of the second fan based on the driving force of the first fan, the second fan can be driven according to the ease with which the dust falls. Thus, if the ease with which the dust falls is high, the second fan can be driven with a smaller driving force, thereby reducing energy consumption.

[0087] (Note 3) The second fan adjusts its driving force according to the degree to which the dust falls from the filter. The dust collector described in Appendix 1 or Appendix 2.

[0088] As described above, the control unit controls the second fan so that its driving force is adjusted according to the degree to which the dust falls from the filter.

[0089] According to the invention described in Appendix 3, the second fan adjusts its driving force according to the degree to which the dust falls from the filter. Therefore, if the dust falls easily, the second fan is driven with a smaller driving force, thus reducing energy consumption.

[0090] (Note 4) Multiple rooms are provided, each equipped with at least one of the aforementioned filters. The gas supply is carried out for each room. The second fan is driven in each room according to the degree to which dust falls easily from the filter provided in that room. A dust collector as described in any one of the items in Appendix 1 to Appendix 3.

[0091] As described above, the control unit controls the second fan to be driven in accordance with the degree to which dust falls from the filter provided in each room.

[0092] According to the invention described in Appendix 4, the second fan is driven in accordance with the degree to which dust falls from the filter provided in each room, so that the second fan can be driven more precisely in each room. [Explanation of symbols]

[0093] 10 Dust collector 44 Filtration fan 40 Backwash Fan 52 CPU 52C Motor Drive Unit Rooms 14R1-14R3 16F11~16F32 Filter 100 electric furnaces

Claims

1. A first fan is used to pass the introduced dust-laden air through a filter and discharge it to the outside. A second fan for supplying gas to the filter in the opposite direction to the passage direction of the dust-containing air, for removing dust adhering to the filter, A dust collector equipped with, The second fan operates while the first fan is operating, and when no gas is supplied to the filter, it is driven with a smaller driving force than when gas is supplied. Dust collector.

2. The second fan adjusts its driving force based on the driving force of the first fan. The dust collector according to claim 1.

3. The second fan adjusts its driving force according to the degree to which the dust falls from the filter. The dust collector according to claim 1.

4. Multiple rooms are provided, each equipped with at least one of the aforementioned filters. The gas supply is carried out for each room. The second fan is driven in each room according to the degree to which dust falls easily from the filter provided in that room. The dust collector according to claim 1.

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