Method for regenerating a dust collector and its metal filter

Abstract

[Problem] To provide a dust collector and a regeneration method for a metal filter of the dust collector, whereby the metal filter can be easily regenerated while attached to the dust collector. [Solution] This dust collector 1 includes a metal filter 6 including metal fibers. The dust collector is configured by partitioning, with a dividing wall 3, the interior of a body 2 into a dust collection chamber S1 and a purifying gas chamber S2, and attaching the metal filter 6 that is open to the purification gas chamber S1 to the dividing wall 3. The dust collector includes a regeneration means for regenerating the metal filter 6 while the metal filter 6 is attached to the dividing wall 3. Here, the regeneration means comprises: a heat medium supplying means such as a steam generator 20 or a heat storing device 30; and an overheating means constituted by a power supply device 40. Further, this regeneration method for the metal filter 6 includes heating the metal filter 6 to a temperature at which the metal fibers included in the metal filter 6 thermally expand and gaps between the metal fibers widen, with the metal filter 6 being attached to the dividing wall 3 of the dust collector 1.

Description

[Technical Field]

[0001] The present invention relates to a dust collector for removing foreign matter such as dust contained in gas and a method for regenerating a metal filter thereof. [Background Art]

[0002] For example, various gases discharged from blast furnaces, electric furnaces, waste treatment furnaces and the like contain foreign matter such as dust, and such foreign matter is removed by a dust collector.

[0003] As the above-mentioned dust collector, one using an external filtration type bag filter is generally used (see, for example, Patent Document 1). In this type of dust collector, gas flows from the outside to the inside of a bottomed cylindrical (bag-shaped) bag filter, whereby foreign matter contained in the gas is removed (collected). Therefore, as dust collection progresses, foreign matter adheres to the outer peripheral surface of the bag filter, increasing the ventilation resistance (pressure loss) of gas passing through the bag filter, which causes a problem that the purification capacity of the dust collector decreases.

[0004] Therefore, backwashing is performed in which high-pressure compressed air is instantaneously injected into each bag filter to periodically shake off and remove foreign matter adhering to the bag filter.

[0005] However, since bag filters are generally made of cloth (nonwoven fabric), even if backwashing is performed periodically, the performance of the bag filter cannot be recovered after long-term use. A bag filter with reduced performance must eventually be discarded and replaced with a new one, which causes a problem of great economic loss.

[0006] Therefore, Patent Document 2 proposes a circulation type filter regeneration mechanism that regenerates a nonwoven fabric filter by heating the nonwoven fabric filter in the process of circulating it wound around a driving roller and a driven roller, reducing the viscosity of oil mist contained in the nonwoven fabric filter to improve its fluidity, and blowing compressed air onto the nonwoven fabric filter to blow off the oil mist.

[0007] Furthermore, Patent Document 3 proposes a method for cleaning metal fiber filters used in forming thermoplastic resin films. Specifically, this cleaning method involves steam heating the metal fiber filter, immersing the metal fiber filter in an acid or alkali, and ultrasonic cleaning the metal fiber filter to remove resin degradation products contained in the metal filter. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2008-296128 [Patent Document 2] Japanese Patent Publication No. 2008-068152 [Patent Document 3] Japanese Patent Publication No. 2019-013890 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, the circulating filter regeneration mechanism proposed in Patent Document 2 primarily separates and removes oil mist contained in the nonwoven fabric filter installed in the air purification device. Because a complex mechanism is incorporated into the nonwoven fabric filter, there is a problem that the entire device becomes large and expensive in devices equipped with a large number of nonwoven fabric filters.

[0010] Furthermore, the metal filter cleaning method proposed in Patent Document 3 requires multiple steps, including chemical treatment, and its application is limited to the formation of thermoplastic resin films. In addition, it is not possible to regenerate the metal filter while it is still attached to the device, which presents a problem as it requires a lot of effort and time for regeneration.

[0011] The present invention has been made in view of the above problems, and its object is to provide a dust collector and a method for regenerating the metal filter thereof that can be easily regenerated while the metal filter remains attached to the dust collector. [Means for solving the problem]

[0012] To achieve the above objective, the dust collector according to the present invention is equipped with a metal filter containing metal fibers, the interior of the main body is divided into a dust collection chamber and a purified gas chamber by a partition wall, the metal filter is attached to the partition wall, and is characterized by being equipped with a regeneration means for regenerating the metal filter while it remains attached to the partition wall.

[0013] Here, the regeneration means includes a heating means for heating the metal filter to a temperature at which the metal fibers contained in the metal filter expand due to heat and widen the gaps between the metal fibers, and the heating means is composed of a heat transfer medium supply means for supplying a heat transfer medium into the metal filter. In this case, the heat transfer medium is high-temperature, high-pressure steam, and the heat transfer medium supply means may include a vertically movable spray nozzle for spraying the high-temperature, high-pressure steam into the metal filter. Furthermore, the heating means may also include a drying means for drying the metal filter after it has been heated by the high-temperature, high-pressure steam by blowing pulsed air or dry air onto it.

[0014] Furthermore, the heat transfer medium supplied into the metal filter by the heat transfer medium supply means is high-temperature air, and the dust collector may also be equipped with a heat storage device that heats the air using the stored heat.

[0015] Furthermore, the heating means may consist of a power supply device that energizes a conductive metal retainer incorporated within the metal filter to generate heat in the retainer.

[0016] The present invention provides a method for regenerating a metal filter, characterized in that, while the metal filter is attached to the partition wall of a dust collector, the metal filter is heated to a temperature at which the metal fibers contained in the metal filter expand due to thermal expansion, thereby widening the gaps between the metal fibers. [Effects of the Invention]

[0017] According to the present invention, while the metal filter remains attached to the partition wall of the dust collector, the metal filter is heated by a heating means (heat transfer medium supply means or power supply device) to a temperature at which the metal fibers contained in the metal filter expand due to thermal expansion, thereby widening the gaps between the metal fibers. This effectively separates and removes foreign matter that has entered the gaps between the metal fibers, and allows the metal filter, whose performance has deteriorated due to the adhesion of foreign matter, to be regenerated and reused.

[0018] Therefore, there is no need to discard metal filters with degraded performance as in the past, preventing waste of resources and environmental pollution. Furthermore, since the metal filters are regenerated while still attached to the dust collector, there is no need to remove the metal filters from the dust collector during regeneration, allowing for simple and quick regeneration. In addition, the regeneration mechanism is relatively simple, consisting of heating means such as a heat transfer medium supply and a power supply, thus avoiding the need to increase the size and cost of the dust collector. [Brief explanation of the drawing]

[0019] [Figure 1] This is a longitudinal cross-sectional view showing the state of the dust collector according to the present invention during normal operation (dust collection). [Figure 2] This is an enlarged detailed cross-sectional view of section A in Figure 1. [Figure 3] This is a longitudinal cross-sectional view showing the state of the dust collector according to the present invention during backwashing. [Figure 4] This is a longitudinal cross-sectional view of the metal filter portion of a dust collector, illustrating a method for regenerating a metal filter according to Embodiment 1 of the present invention. [Figure 5] (a) is a front view of the injection nozzle, (b) is a cross-sectional view of (a) along line BB, and (c) is a cross-sectional view of (a) along line CC. [Figure 6] It is a longitudinal sectional view of a metal filter portion of a dust collector showing a method for regenerating a metal filter according to Embodiment 2 of the present invention. [Figure 7] It is a longitudinal sectional view of a metal filter portion of a dust collector showing a method for regenerating a metal filter according to Embodiment 3 of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0020] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0021] [Dust collector] First, the configuration of a dust collector according to the present invention will be described below with reference to FIGS. 1 to 3.

[0022] FIG. 1 is a longitudinal sectional view showing the state of the dust collector according to the present invention during normal operation (during dust collection), FIG. 2 is an enlarged detailed sectional view of part A in FIG. 1, and FIG. 3 is a longitudinal sectional view showing the state of the same dust collector during backwashing.

[0023] The dust collector 1 according to the present invention includes a closed container-shaped main body (housing) 2, and the interior of the main body 2 is partitioned by a horizontal partition wall 3 into a lower dust collection chamber S1 and an upper purified gas chamber S2. Here, the volume of the dust collection chamber S1 is set to be larger than the volume of the purified gas chamber S2, the lower portion of the main body 2 is formed in a funnel shape tapering downward, and a rotary valve 4 is provided at a foreign matter discharge port 2a opened at the lower end of the main body 2. Further, a gas inflow pipe 5 is connected to an intermediate height position on a side portion of the main body 2, one end of the gas inflow pipe 5 is connected to a blast furnace, an electric furnace, a waste treatment furnace or the like (not shown) that discharges gas, and the other end is connected to the main body 2 of the dust collector 1 as described above and opens into the dust collection chamber S1 in the main body 2.

[0024] Furthermore, the dust collection chamber S1 within the main body 2 houses multiple bottomed cylindrical (bag-shaped) metal filters 6 with their lower ends closed. Each metal filter 6 is suspended vertically, with its upper end supported by a partition wall 3. Inside, as shown in Figure 2, a cylindrical frame-shaped (cage-shaped) retainer 7 is incorporated from above to maintain the shape of the metal filter 6. The metal filters 6 are manufactured by embedding metal fibers (short fibers), such as stainless steel (SUS), titanium, or aluminum, into a base material such as nylon felt or polyester felt using needle punching. The retainer 7 is made of a conductive metal with relatively high electrical resistance, such as stainless steel (SUS), iron, or aluminum.

[0025] On the other hand, a gas outlet pipe 8 is connected to the side of the purified gas chamber S2 formed in the upper part of the main body 2. One end of this gas outlet pipe 8 opens into the purified gas chamber S2, and the other end is connected to a suction fan 9.

[0026] Incidentally, the dust collector 1 according to the present invention is provided with a backwashing device 10 for periodically brushing off and removing foreign matter such as dust adhering to the outer surface of each metal filter 6 using high-pressure compressed air. This backwashing device 10 consists of a compressed air supply source 11 such as a compressor installed outside the main body 2 and an injector pipe 12 extending from the compressed air supply source 11.

[0027] The injector pipe 12 is introduced into a purified gas chamber S2 formed in the upper part of the main body 2 and extends horizontally within the purified gas chamber S2. An on / off valve 13 is provided between the main body 2 and the compressed air supply source 11 of the injector pipe 12. Air nozzles 16 are attached to multiple locations on the portion of the injector pipe 12 inserted into the main body 2 (positions facing the upper end opening 6a of each metal filter 6), and these nozzles open toward the upper end opening 6a of each metal filter 6. In this embodiment, the injector pipe 12 is made of SGP pipe (carbon steel pipe for piping), SUS pipe (stainless steel pipe), etc.

[0028] Furthermore, in the dust collector 1 according to the present invention, if the purification performance of the metal filter 6 deteriorates due to clogging caused by the adhesion of foreign matter, the foreign matter is removed by backwashing as described later. However, if the purification performance of the metal filter 6 deteriorates due to prolonged use and does not recover even with backwashing, a regeneration means is provided to regenerate the metal filter 6 without discarding it, while it remains attached to the dust collector 1 (partition 3). This regeneration means is composed of a heating means, as will be explained in each embodiment of the regeneration method described later. This heating means consists of a steam generator 20 (see Figure 4), a heat storage device 30 (see Figure 6), and a power supply device 40 (see Figure 7), which serve as heat transfer medium supply means for supplying a heat transfer medium (high-temperature, high-pressure steam or high-temperature air) into the metal filter 6. Details of these will be described later.

[0029] Next, the operation of the dust collector 1 configured as described above will be explained below for both normal operation (dust collection) and backwashing. 1) Operation during normal operation (dust collection): During normal operation of the dust collector 1 (dust collection), as shown in Figure 1, the rotary valve 4 located at the lower end of the main body 2 is closed, and the backwashing device 10 is stopped (non-operating). When the suction fan 9 is driven to rotate in this state, both the dust collection chamber S1 and the purified gas chamber S2 inside the main body 2 become negative pressure, and gas discharged from a waste treatment furnace (not shown) is drawn in by this negative pressure and flows into the dust collection chamber S1 inside the main body 2 from the gas inlet pipe 5, as indicated by the arrow in Figure 1.

[0030] As described above, the gas flowing into the dust collection chamber S2 passes through multiple metal filters 6, and foreign matter such as dust contained in it is collected by each metal filter 6 and adheres to the outer surface of each metal filter 6. Then, the gas, purified by the removal of foreign matter by the metal filters 6, is discharged into the purified gas chamber S2 from the upper end opening 6a of each metal filter 6, as shown by the arrows in Figure 1, flows out of the main body 2 through the gas outlet pipe 8, is sucked in by the suction fan 9 and sent to a processing device (not shown).

[0031] As the dust collection process described above is repeated, foreign matter such as dust gradually adheres to and accumulates on the outer surface of each metal filter 6, increasing the airflow resistance of the gas passing through each metal filter 6. When the airflow resistance of the gas passing through each metal filter 6 reaches a predetermined value, as detected by a pressure gauge (not shown), or after a predetermined time has elapsed, the backwashing device 10 is activated and each metal filter 6 is backwashed with compressed air.

[0032] Next, the operation of the dust collector 1 during this backwashing process will be explained below with reference to Figure 3. 2) Action during backwashing: Figure 3 is a vertical cross-sectional view showing the state of the dust collector 1 according to the present invention during backwashing. Backwashing of each metal filter 6 is performed as follows by driving the backwashing device 10. That is, when a compressed air supply source 11, such as a compressor (not shown), is driven and the on / off valve 13 is opened, high-pressure compressed air discharged from the compressed air supply source 11 flows through the injector pipe 12 in the direction of the arrow shown, and is instantaneously injected from each air nozzle 14 toward the upper end opening 6a of each metal filter 6. As a result, foreign matter adhering to the outer surface of each metal filter 6 is blown off and removed by the compressed air. Then, the foreign matter such as dust blown off from the outer surface of each metal filter 6 falls into the dust collection chamber S2 as shown by the arrow in Figure 3, is collected at the bottom of the main body 2, and is discharged to the outside of the main body 2 from the foreign matter discharge port 2a when the rotary valve 4 opens and is recovered.

[0033] The backwashing described above restores the purification performance of the metal filter 6 to some extent. However, if the purification performance of the metal filter 6 is not restored even after this backwashing, the metal filter 6 is regenerated by the regeneration means as described above. The regeneration of the metal filter 6 is performed when the differential pressure inside and outside the metal filter 6 exceeds a predetermined value (for example, 1.5 kPa), or periodically (for example, every three years).

[0034] [How to regenerate metal filters] The present invention provides a method for regenerating a metal filter 6, characterized by heating the metal filter 6 to a temperature at which the metal fibers contained in the metal filter 6 expand due to heat, thereby widening the gaps between the metal fibers, while the metal filter 6 remains attached to the dust collector 1 (partition 3). The method for regenerating the metal filter 6 will be described below in accordance with each embodiment.

[0035] <Embodiment 1> Figure 4 is a longitudinal cross-sectional view of the metal filter portion of a dust collector showing a metal filter regeneration method according to Embodiment 1 of the present invention, Figure 5(a) is a front view of the spray nozzle, Figure 5(b) is a cross-sectional view of Figure 5(a) along line BB, and Figure 5(c) is a cross-sectional view of Figure 5(a) along line CC.

[0036] In this embodiment, the heating means is comprised of a heat transfer medium supply means, and the heat transfer medium supply means is comprised of a steam generator 20 that supplies high-temperature, high-pressure steam as a heat transfer medium into the metal filter 6.

[0037] A pipe 21 extends from the steam generator 20, and when regenerating the metal filter 6, as shown in Figure 4, the tip of the pipe 21 is inserted from above into the metal filter 6 (retainer 7) while the metal filter 6 remains attached to the partition wall 3. Here, a spray nozzle 22 for spraying high-temperature, high-pressure steam into the surrounding area is attached to the tip of the pipe 21.

[0038] The details of the configuration of the injection nozzle 22 are shown in Figure 5. This injection nozzle 22 is constructed by connecting and integrating two upper and lower discs 22A and 22B with a cylindrical side wall 22C. The tip of the pipe 21 is inserted into and fixed to the center of the upper disc 22A, and multiple (eight in the illustrated example) circular injection holes 22a are provided in the side wall 22C at equal angular pitches (45° pitches) in the circumferential direction. In this embodiment, the number of injection holes 22a is set to eight, but the number of injection holes 22a can be any number as long as there are multiple.

[0039] As shown in Figure 4, the pipe 21, along with the injection nozzle 22 attached to its tip, is inserted into the metal filter 6 (retainer 7) from above. By manually or automatically moving the pipe 21 and injection nozzle 22 up and down inside the metal filter 6 as indicated by the arrows in Figure 4, high-temperature, high-pressure steam generated in the steam generator 20 is supplied to the pipe 21. As a result, high-temperature, high-pressure steam is ejected outwards from multiple injection holes 22a opening in the injection nozzle 22 inserted into the metal filter 6. The metal filter 6 is uniformly heated along its entire length in both the circumferential and vertical directions by the high-temperature, high-pressure steam blown onto its inner circumference. When the metal filter 6 is heated in this way by the high-temperature, high-pressure steam, the metal fibers contained in the metal filter 6 expand due to the heat, widening the gaps between the metal fibers. This effectively separates any deposits that have entered and adhered to the gaps between the metal fibers, and the separated deposits are blown away and removed by the high-temperature, high-pressure steam passing through the metal filter 6. Therefore, the metal filter 6, whose purification performance has deteriorated due to the accumulation of deposits, is regenerated, and this regenerated metal filter 6 is used again.

[0040] Therefore, there is no need to dispose of the metal filter 6 when its purification performance has deteriorated, as in the past, thus preventing waste of resources and environmental pollution. Furthermore, since the metal filter 6 is regenerated while still attached to the partition wall 3 of the dust collector 1, there is no need to remove the metal filter 6 from the dust collector 1 when regenerating it, allowing for easy and quick regeneration of the metal filter 6. In addition, the regeneration means is relatively simple, consisting of a steam generator 20, pipes 21, and spray nozzles 22, which are heat transfer medium supply means, thus avoiding an increase in the size and cost of the dust collector 1.

[0041] By the way, in this embodiment, if a drying means is provided to dry the metal filter 6, which has been moistened by blowing high-temperature, high-pressure steam, by blowing pulsed air or dry air, it is possible to prevent foreign matter from adhering to the metal filter 6.

[0042] Furthermore, the regeneration of the metal filters 6 by injecting high-temperature, high-pressure steam described above is performed for each individual metal filter 6.

[0043] <Embodiment 2> Next, a method for regenerating a metal filter according to Embodiment 2 of the present invention will be described below with reference to Figure 6.

[0044] Figure 6 is a longitudinal cross-sectional view of the metal filter portion of a dust collector showing a method for regenerating a metal filter according to Embodiment 2 of the present invention. In this figure, the same elements as those shown in Figure 4 are denoted by the same reference numerals, and further explanation of them will be omitted below.

[0045] In this embodiment, the heat transfer medium supply means, which serves as the heating means, is comprised of a heat storage device 30 that supplies high-temperature air as the heat transfer medium into the metal filter 6. The heat storage device 30 is equipped with a latent heat storage material that liquefies and stores heat at a temperature above its melting point. For example, it stores waste heat discharged from blast furnaces, electric furnaces, waste treatment furnaces, etc., and uses the stored heat to heat air and generate high-temperature air.

[0046] The high-temperature air generated by heating the air with the heat storage device 30 is supplied to the injection nozzle 22 via the pipe 21, similar to the first embodiment. When the pipe 21 and the injection nozzle 22 attached to its tip are manually moved up and down inside the metal filter 6 as shown by the arrows in Figure 6, high-temperature air is ejected outwards from the multiple injection holes 22a (see Figure 5) opening in the injection nozzle 22. As a result, the metal filter 6, to which the high-temperature air is blown on its inner circumference, is uniformly heated along its entire length in both the circumferential and vertical directions.

[0047] As described above, when the metal filter 6 is heated by high-temperature air, the metal fibers contained in the metal filter 6 expand due to the heat, widening the gaps between the metal fibers. This effectively separates any deposits that have become lodged in the gaps between the metal fibers, and the separated deposits are blown away and removed from the metal filter 6 by the high-temperature air passing through it. As a result, the metal filter 6, which had deteriorated in performance, is regenerated, and this regenerated metal filter 6 can continue to be used.

[0048] Therefore, with the regeneration method according to this embodiment, there is no need to discard the metal filter 6 with reduced performance as in the conventional method, thus preventing waste of resources and environmental pollution. In addition, the same effects as in Embodiment 1 can be obtained in this embodiment as well. In the regeneration method according to this embodiment, regeneration is performed on each metal filter 6 separately.

[0049] <Embodiment 3> Next, a method for regenerating a metal filter according to Embodiment 3 of the present invention will be described below with reference to Figure 7.

[0050] Figure 7 is a longitudinal cross-sectional view of the metal filter portion of a dust collector showing a method for regenerating a metal filter according to Embodiment 3 of the present invention. In this figure, the same elements as those shown in Figures 4 and 6 are denoted by the same reference numerals, and further explanation of them will be omitted below.

[0051] In this embodiment, the heating means is comprised of a power supply device 40 that energizes a conductive metal retainer 7 incorporated within a metal filter 6, thereby generating heat in the retainer 7. The retainer 7 is made of a conductive metal with high electrical resistance, such as stainless steel (SUS), iron, or aluminum.

[0052] In this embodiment, a low-voltage, high-current power supply unit 40 is used, and a power supply line 41 extending from the power supply unit 40 is inserted from above into the metal filter 6 and retainer 7. A weight 42 attached to the end (lower end) of this power supply line 41 is in contact with the lower end of the retainer 7. Here, since the weight 42 is made of a conductive metal such as iron, when this weight 42 comes into contact with the retainer 7, which is also made of a conductive metal, the weight 42 and the retainer 7 become electrically conductive, and the retainer 7 and the power supply unit 40 are electrically connected via the power supply line 41. The retainer 7 is also grounded via an earth wire 43. Alternatively, the weight 42 may be made of a magnet and magnetically attracted to the retainer 7.

[0053] When regenerating the metal filter 6 using the method according to this embodiment, as shown in Figure 7, the power supply unit 40 is electrically connected to the retainer 7 via the power supply line 41, and the retainer 7 is grounded via the ground wire 43. When power is supplied to the retainer 7 from the power supply unit 40 via the power supply line 41 in this state, the retainer 7 functions as an electric heater and generates heat. As a result, the metal filter 6 is uniformly heated from the inside in the circumferential and vertical directions by the retainer 7, and the metal fibers contained in the metal filter 6 expand due to the heat, widening the gaps between the metal fibers. As a result, deposits that have entered the gaps between the metal fibers of the metal filter 6 are effectively separated and removed, and the metal filter 6 whose performance has deteriorated due to deposits is regenerated, allowing the metal filter 6 to be used repeatedly.

[0054] Therefore, with the regeneration method according to this embodiment, just like in embodiments 1 and 2, there is no need to discard the metal filter 6 with reduced performance as in the conventional method, thus preventing waste of resources and environmental pollution. In addition, the same effects as in embodiments 1 and 2 can be obtained in this embodiment as well. In addition, in the regeneration method according to this embodiment, regeneration is performed on each metal filter 6 separately.

[0055] By the way, the above explanation described a steam generator 20 that supplies high-temperature, high-pressure steam into the metal filter 6 and a heat storage device 30 that supplies high-temperature air into the metal filter 6 as examples of heat transfer medium supply means. However, any other heat transfer medium other than high-temperature, high-pressure steam or high-temperature air can be used to supply any heat transfer medium into the metal filter 6.

[0056] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the technical idea described in the claims, specification, and drawings. [Explanation of Symbols]

[0057] 1. Dust collector 2 Main unit 3 Bulkhead 4 Rotary valves 5. Gas inlet pipe 6. Metal filter 6a Upper end opening of the metal filter 7 Retainer 8. Gas outlet pipe 9. Suction fan 10 Backwash device 11 Compressed air supply source 12 Injector pipes 13. On / off valve 14 Air nozzles 20. Steam generator (heat transfer medium supply means (heating means)) 21 pipes 22 Spray nozzles 30 Heat storage device (thermal medium supply means (heating means)) 40 Power supply device (heating means) 41 Power line 42 weights 43. Ground wire S1 Dust Collection Room S2 Gas Purification Chamber

Claims

1. A metal filter formed by implanting metal fibers into a base material by processing, The inside of the main unit is divided into a dust collection chamber and a purifying gas chamber by a partition wall. A dust collector comprising the aforementioned metal filter attached to the partition wall, The system includes a regeneration means for regenerating the metal filter while the metal filter remains attached to the partition wall, The regeneration means includes a heating means for heating the metal filter to a temperature at which the metal fibers contained in the metal filter expand due to heat and widen the gaps between the metal fibers. A dust collector characterized by the following features.

2. The metal filter has an upper end opening that communicates with the inside of the metal filter from the side of the purifying gas chamber and functions as a passage for the purifying gas, The regeneration means includes a pipe that is inserted into the metal filter through the upper end opening during the regeneration of the metal filter and removed from the upper end opening after the regeneration is complete. The dust collector according to feature 1.

3. The dust collector according to claim 1, characterized in that the heating means is comprised of a heat medium supply means for supplying a heat medium into the metal filter.

4. The dust collector according to claim 3, wherein the heat transfer medium is high-temperature, high-pressure steam, and the heat transfer medium supply means comprises a vertically movable spray nozzle that sprays the high-temperature, high-pressure steam into the metal filter.

5. The dust collector according to claim 4, further comprising a drying means for drying the metal filter, which has been heated by the aforementioned high-temperature, high-pressure steam, by blowing pulsed air or dry air onto it.

6. The dust collector according to claim 3, characterized in that the heat transfer medium is high-temperature air and the dust collector is equipped with a heat storage device that heats the air with the stored heat.

7. The dust collector according to claim 1, characterized in that the heating means is comprised of a power supply device that energizes a conductive metal retainer incorporated within the metal filter to generate heat in the retainer.

8. A method for regenerating the metal filter of a dust collector according to any one of claims 1 to 7, A method for regenerating a metal filter, characterized by heating the metal filter to a temperature at which the metal fibers contained in the metal filter expand due to heat, thereby widening the gaps between the metal fibers, while the metal filter remains attached to the partition wall.

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