JP2005058903A - Filter apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter apparatus not interrupting filtration, having relatively high filtering precision and not causing a problem such as the lowering of filtering efficiency or the like. <P>SOLUTION: This filter apparatus is constituted so that an accumulation layer of a granular filter aid is formed on the surface of a filter plate and a liquid is filtered by the accumulation layer and equipped with a hollow filter unit 1 having the filter plate 17 provided at least on a part of the surface thereof and a filter tank 2 storing a liquid to be filtered and housing the filter unit 1. The filter unit 1 is housed in the filter tank 2 so as to turn the surface of the filter plate 17 laterally and the filter aid is supplied to the vicinity of the surface of the filter plate 17 while the liquid in the filter unit 1 is sucked by a suction pump 3 and air bubbles left in the filter tank are sucked from the upper part of the filter unit 1. By this constitution, a problem such as the lowering of filtering efficiency or the like is eliminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a filtration device that removes foreign substances existing in a liquid such as a cutting liquid used in, for example, a grinding machine, a lathe, a machining center, and the like.

  Conventionally, as a cutting fluid filtration device used in a machine tool such as a grinding machine or a lathe, for example, the one shown in FIG. 6 has been used. This apparatus uses diatomaceous earth as a filter medium, forms the diatomaceous earth precoat layer on the outer peripheral surface of the filter tube 51, and allows the cutting fluid to permeate through the precoat layer for filtration.

  That is, this apparatus includes a dirty tank 53 for storing dirty liquid discharged from a machine tool, a filter tube 51 in which a diatomaceous earth precoat layer is formed, and a filter chamber 52 for filtering the dirty liquid, and the filter And a clean tank 54 for storing the clean liquid filtered in the chamber 52. Further, a diatomaceous earth supply feeder 56 is provided, and a slurry tank 57 for generating a diatomaceous earth slurry is provided. In FIG. 4, 58 is a recovery tank for temporarily storing used diatomaceous earth together with dirty liquid, 59 is a liquid and solid substance separated from the mixed liquid of used diatomaceous earth and dirty liquid collected in the recovery tank to remove diatomaceous earth and the like. It is a separator that liquefies.

  The filtration device is used as follows. That is, first, diatomaceous earth in the diatomaceous earth supply feeder 56 is put into the slurry tank 57 and mixed with the clean liquid to generate a slurry. This slurry is introduced into the filter chamber 52 by the slurry pump 60, returned to the slurry tank 57, and circulated. At this time, a diatomaceous earth precoat layer 61 is formed on the outer periphery of the filter tube 51 in the filter chamber 52, as shown in FIG. In FIG. 7, 62 is a punch hole formed in a large number on the peripheral wall of the filter tube 51, and 63 is a metal mesh wound around the outer periphery of the filter tube 51.

  Next, after the precoat layer 61 is generated, the slurry pump 60 is stopped and the filter pump 55 is operated. Then, the dirty liquid in the dirty tank 53 is introduced into the filter chamber 52 so that the lower space of the filter chamber 52 is pressurized, filtered through the precoat layer 61 formed in the filter tube 51, and filtered clean. Liquid is sent from the filter chamber 52 to the clean tank 54. At this time, the foreign matter in the dirty liquid is captured by the precoat layer 61, and the pressure in the lower space of the filter chamber 52 gradually increases as the precoat layer 61 becomes clogged.

  When the pressure in the lower space of the filter chamber 52 reaches a predetermined value, the dump valve 64 at the lower part of the filter chamber 52 is opened, the air valve 65 at the upper part of the filter chamber 52 is opened, and compressed air is introduced from the upper part of the filter chamber 52. The clean liquid in the upper part of the chamber 52 is caused to flow backward to collect diatomaceous earth (precoat layer 61) mixed with foreign substances in the recovery tank 58 together with the dirty liquid, and temporarily stored.

  Then, after the slurry in the slurry tank 57 is circulated again to form the diatomaceous earth precoat layer 61 on the filter tube 51, the cycle of filtering the dirty liquid by operating the filter pump 55 is repeated. The slurry of the used diatomaceous earth and dirty liquid in the recovery tank 58 is separated from the diatomaceous earth and foreign matter and dirty liquid by the separator 59, and the diatomaceous earth and the like are drained and discharged to the waste box 66. It is collected in the dirty tank 53.

Here, the prior art which the applicant grasps | ascertains about the above filtration apparatuses is shown.
Japanese utility model 3-38120 microfilm Japanese Utility Model No. 61-102215 microfilm Japanese Patent Laid-Open No. 61-61606

  However, although the filtration apparatus has a relatively high filtration accuracy, it requires a precoat cycle for forming the precoat layer 61 on the filter tube 51 in order to filter the dirty liquid with the precoat layer 61 of diatomaceous earth. Since this precoat cycle is performed while pressurizing the lower space of the filter chamber 52 with the slurry pump 60, it takes a considerable time to form the precoat layer 61. During this time, the filtration is interrupted and clean fluid is supplied to the machine tool. There is a problem that it cannot be sent. In addition, a precoat circulation device for circulating the slurry is required to form the precoat layer 61, which increases the size of the device itself and increases the installation space, and increases the cost.

  Therefore, an apparatus for forming the precoat layer 61 by sucking the internal space of the filter chamber 52 has been devised (Patent Document 1).

  However, in the apparatus for forming the precoat layer 61 by sucking the internal space of the filter chamber 52, bubbles 67 remain in the filter chamber 52 as shown by the chain line in FIG. May reduce efficiency. That is, if bubbles 67 remain in the filter chamber 52 and stick to the inner wall of the filter chamber 52, the liquid flows in a region without the bubbles 67, and filtration is not performed in the region where the bubbles 67 are stuck. If it will be in such a state, the filtration area will be reduced significantly and it will cause the filtration efficiency to fall significantly. Further, since the liquid flow does not occur in the portion where the bubbles 67 are stuck to the inner wall of the filter chamber 52, the precoat layer 61 is not well formed in the region, or the precoat layer 61 formed with great effort is not provided with a pump or the like. There was a problem of peeling off due to a slight vibration.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a filtration apparatus in which filtration is not interrupted, filtration accuracy is relatively high, and problems such as reduction in filtration efficiency do not occur.

  In order to achieve the above object, the filtration device of the present invention is a filtration device for forming a particulate filter aid deposition layer on a plate surface of a filter plate, and filtering the liquid with the deposition layer, at least on the surface A hollow filter unit provided with a filter plate in a part thereof, and a filtration tank in which a liquid to be filtered is stored and a filter unit is accommodated, and the filter unit has a plate surface of the filter plate facing sideways. The filter tank is accommodated in the filtration tank, and the filter aid is supplied to the vicinity of the plate surface of the filter plate by the aid supply means, and the liquid in the filter unit is sucked by the suction pump and remains inside from the upper part of the filter unit. The gist of the invention is that the air bubbles are sucked by the gas suction means.

  That is, in the filtration device of the present invention, the filter unit is accommodated in the filtration tank so that the plate surface of the filter plate faces sideways, and the auxiliary agent supplying means supplies the filter aid to the vicinity of the plate surface of the filter plate, The liquid in the filter unit is configured to be sucked by a suction pump. Therefore, due to the negative pressure in the filter unit generated by the suction pump, the filter aid supplied from the auxiliary agent supply means to the vicinity of the plate surface of the filter plate is sucked to the plate surface of the filter plate and quickly forms a deposited layer. Thus, the filtration interruption time associated with the formation of the deposited layer is significantly shortened, and the filtration efficiency is prevented from being lowered. Therefore, the filtration is hardly interrupted as in the prior art, and high filtration accuracy by the filter aid can be ensured. Furthermore, since the filter plate is accommodated in the filtration tank so that the plate surface faces sideways, the deposited layer of the filter aid that has been used can be easily peeled off from the plate surface of the filter plate and dropped. The filtration interruption time can be greatly reduced.

  Further, the filtration device of the present invention is configured to suck the air bubbles remaining inside from the upper part of the filter unit by the gas suction means, and the air bubbles remaining in the filter unit are sucked and removed. In addition, there is almost no reduction in filtration efficiency due to the action of bubbles remaining in the filter unit. In addition, there is almost no trouble that the deposited layer of the filter aid is not formed well due to the influence of bubbles remaining in the filter unit, or the deposited layer formed is peeled off, so that stable filtration accuracy is maintained. Will be able to.

  In the filtration device of the present invention, the gas suction means is an ejector device provided in a pump communication path to which a suction pump for sucking the liquid in the filter unit is connected, and the ejector device and the upper part of the filter unit are bubbles. When connected by a discharge path, the liquid flow in the pump communication path generated by the pump that sucks the liquid in the filter unit is used to generate a negative pressure in the bubble discharge path by the ejector device. Air bubbles can be removed by suction. Thus, since the negative pressure is generated using the flow of the liquid obtained by the suction pump, it is not necessary to separately provide power for sucking bubbles, and the equipment is simplified and the energy efficiency is improved.

  In the filtration device of the present invention, the downstream side of the pump communication path is a clean liquid supply line, and the clean liquid is supplied to the pump communication path when the negative pressure in the filter unit reaches a predetermined value. By removing the negative pressure in the filter unit and peeling off the used filter aid from the plate surface of the filter plate, at the same time, when the clean liquid is supplied to the supply line, When the filter layer becomes clogged and the negative pressure in the filter unit reaches a predetermined value, the negative pressure in the filter unit is released and the used filter aid is removed from the filter plate. At the same time as peeling from the plate surface, clean liquid is supplied to the supply line. In general, with this type of filtration device, when the filter aid is peeled off, the negative pressure in the filter unit is released and the filtration is temporarily interrupted, but at that time, clean liquid is supplied to the supply line simultaneously with the release of the negative pressure. By doing so, the clean liquid can be supplied to the equipment using the clean liquid such as a machine tool while the filter aid is being peeled off, so that the supply of the clean liquid is not interrupted at all.

  In the filtration device of the present invention, the negative pressure in the filter unit is released when the negative pressure in the filter unit reaches a predetermined value, and the filter unit is swung by the unit swinging means. When the filter aid is allowed to drop from the plate surface of the filter plate, the filter is automatically filtered when the accumulated layer of filter aid becomes clogged and the negative pressure in the filter unit reaches a predetermined value. The negative pressure in the unit is released, and the filter unit is automatically rocked by the unit rocking means. Then, the release of the negative pressure in the filter unit and the swinging of the filter unit are performed simultaneously, and the used filter aid from the filter plate of the filter unit housed in the filter tank so that the plate surface of the filter plate faces sideways. The deposited layer easily peels off and falls, and it takes no time to remove the deposited layer, and the interruption time of the filtration accompanying the peeling of the deposited layer is very short.

  In the filtration apparatus of the present invention, when a plurality of filter units are provided, and the plurality of filter units are configured to release the negative pressure in the filter units substantially simultaneously, the filtration efficiency corresponding to the plurality of filter units is achieved. Can be ensured, and adverse effects on the lifetime of the deposited layer can be prevented.

  That is, since the filtration is not performed while the negative pressure in the filter unit is released and the filter aid is peeled off, in order not to interrupt the supply of the clean liquid while peeling the filter aid, Conventionally, a plurality of filter units are alternately or sequentially released from negative pressure, and the filter aid is peeled off so that the entire apparatus does not stop filtration. As described above, when the plurality of filter units are alternately or sequentially peeled off, the plurality of filter units are stopped in order, so that the entire apparatus obtains a filtration efficiency corresponding to the number of filter units. I could not. In addition, the used filter aid is sucked into the filter unit adjacent to the filter unit from which the filter aid is peeled off to shorten the life of the deposited layer, or vibration is transmitted to the adjacent filter unit and the deposited layer is peeled off. It was a factor.

  In the present invention, as described above, the clean liquid is supplied to the supply line simultaneously with the release of the negative pressure, so that the clean liquid is supplied to the clean liquid use equipment such as a machine tool while the filter aid is being peeled off. Since the supply of clean liquid is not interrupted at all, it becomes possible to release negative pressure from multiple filter units at the same time, and it is possible to ensure the filtration efficiency corresponding to the multiple filter units and to adjoin them. An adverse effect on the deposited layer of the filter unit can be prevented.

  In the filtration device of the present invention, when the filter aid is mainly composed of cellulose fibers, the filter aid is easily bridged on the network and the filter aids are easily entangled with each other, and is deposited very quickly on the plate surface of the filter plate. A layer is formed. Therefore, the filtration accuracy is improved.

  Next, the best mode for carrying out the present invention will be described in detail.

  FIG. 1 shows an embodiment of the filtration device of the present invention. This includes a hollow filter unit 1, a filtration tank 2 in which the filter unit 1 is stored and a dirty tank is stored, a suction pump 3 that sucks the liquid in the filter unit 1, and the above And a slurry tank 4 for storing a slurry of filter aid supplied to the periphery of the filter unit 1. And the deposit layer of a granular filter aid is formed in the surface of the said filter unit 1, and a liquid is filtered with the said deposit layer.

  More specifically, a plurality (two in this example) of filter units 1 are accommodated in the filtration tank 2, and dirty liquid such as grinding liquid discharged from the machine tool is introduced into the filtration tank 2 by the introduction line 11. It has been introduced. In addition, a discharge conveyor 12 for discharging the used filter aid removed from the filter unit 1 is provided at the bottom of the filtration tank 2. The discharge conveyor 12 is laid under the filter units 1 arranged side by side, receives the used filter aid peeled off from each filter unit 1, and discharges it to the outside of the filter tank 2. Yes.

  As shown in FIG. 2, the filter unit 1 has a plurality of (eight in this example) thin box-like filter panels 5 radially on a peripheral wall of a cylindrical body 7 so that the inside communicates with each other. It is arranged and configured. The filter plates 17 on both sides of each filter panel 5 are provided with a number of punch holes 6 and covered with a metal mesh 8. The filter unit 1 is accommodated in the filtration tank 2 so that the plate surface of the filter plate 17 faces sideways (that is, the filter plate 17 itself is in the vertical direction). In addition, although the filter panel 5 was attached to the surrounding wall of the cylindrical body 7, you may connect filter panel 5 radially by planar view, without using the cylindrical body 7. FIG.

  In the upper part of the filter unit 1 (returning to FIG. 1), a slurry supply pipe 15 communicated with the slurry tank 4 via the slurry pump 14 is provided. The slurry tank 4 is provided with a flow switch 23, and when the liquid level is lowered, the electromagnetic on-off valve 24 is opened to replenish clean liquid from the supply line 13, and the filter aid stored in the auxiliary tank 25 is also provided. The agent is replenished by the feeder 26 in such an amount that an appropriate blending amount is obtained. By doing so, an appropriate blending amount of slurry is always supplied.

  As shown in FIG. 3, the slurry supply pipe 15 has a quadrangular annular shape and is disposed on the upper side of the filter unit 1. A supply pipe 16 branched from the slurry supply pipe 15 is suspended between the filter plates 17 of the filter panel 5 arranged radially. The tip opening of the supply pipe 16, that is, the slurry supply opening is located near the center of the plate surface of the filter plate 17. That is, the supply pipe 16 and the supply opening are arranged near the approximate center of the V-shaped filter panel 5. A slurry of filter aid is supplied from the supply pipe 16 to the vicinity of the filter plate 17.

  The inside of the cylindrical body 7 of the filter unit 1 communicates with the suction pump 3 via the pump communication path 9 and sucks the liquid in the hollow filter unit 1. By the suction, the inside of the filter unit 1 is made negative pressure, and the filter aid is sucked to the plate surface (on the surface of the metal mesh 8) of the filter plate 17 of the filter panel 5 to form a deposited layer. Dirty liquid is allowed to pass through and foreign matter is filtered. The clean liquid sucked and filtered by the suction pump 3 is supplied to the machine tool through the supply line 13.

  Thus, the filter unit 1 is accommodated in the filtration tank 2 so that the plate surface of the filter plate 17 faces sideways, and the filter aid is supplied to the vicinity of the plate surface of the filter plate 17, and Since the liquid is sucked by the suction pump 3, the filter aid supplied to the vicinity of the plate surface of the filter plate 17 by the negative pressure in the filter unit 1 generated by the suction pump 3 is It is attracted to the plate surface and quickly forms a deposited layer. Therefore, the filtration is hardly interrupted as in the prior art, and high filtration accuracy by the filter aid can be ensured. Further, since the filter plate 17 is accommodated in the filtration tank so that the plate surface faces sideways, the deposited layer of the used filter aid easily peels off from the plate surface of the filter plate 17 and falls. The interruption time of filtration accompanying peeling can be greatly shortened.

  Here, the pump communication passage 9 is connected to the lower side of the filter unit 1 and sucks the liquid inside from the lower side of the filter unit. By doing in this way, a liquid will be attracted | sucked by interaction with the attraction | suction force of a pump, and gravity, and energy efficiency will improve.

  On the other hand, a break tank 20 for releasing the negative pressure in the pump communication path 9 and the filter unit 1 by supplying clean liquid to the pump communication path 9 via the electromagnetic on-off valve 19 to the filtration device. Is provided. The break tank 20 and the pump communication passage 9 are connected via a break passage 29. The break tank 20 is provided with a flow switch 21. When the liquid level drops, the electromagnetic on-off valve 22 of the clean liquid replenishment path 33 is opened to replenish clean liquid from the supply line 13. .

  Alternatively, the flow switch 21 may not be provided in the break tank 20, and the electromagnetic opening / closing valve 22 may not be provided in the clean liquid replenishment path 33. In this case, the break tank 20 is always replenished with the clean liquid from the clean liquid replenishment path 33, and the overflowed clean liquid is circulated into the filtration tank 2 from the circulation flow path 34. Even in this case, the liquid in the filtration tank 2 is always sucked and filtered by the suction pump 3 and supplied to the machine tool or the like as a clean liquid, so that the filtration tank 2 does not overflow. Moreover, equipment such as the electromagnetic on-off valve 22 and the flow switch 21 can be omitted, which is advantageous in terms of equipment cost and maintenance cost.

  A downstream side of the pump communication path 9 is a supply line 13 for supplying clean liquid to equipment using clean liquid such as machine tools. The pump communication path 9 is provided with a pressure sensor 18 for detecting a pressure change in the pump communication path 9. And when the deposit of the filter aid formed in the filter panel 5 is clogged and the negative pressure in the pump communication path 9 and the filter unit 1 reaches a predetermined value, the electromagnetic on-off valve 19 is opened. It has become.

  Further, the break tank 20 is provided on the upper side of the filtration tank 2, and when the electromagnetic on-off valve 22 is opened, the clean liquid flows into the pump communication path 9 by gravity through the break path 29. Then, when the negative pressure in the filter unit 1 reaches a predetermined value, a clean liquid is supplied to the pump communication passage 9 to release the negative pressure in the filter unit 1 and to replace the used filter aid. At the same time as the separation from the plate surface of the filter plate 17, the clean liquid is supplied to the supply line 13.

  By doing so, when the filtration progresses and the deposited layer of the filter aid becomes clogged and the negative pressure in the filter unit 1 reaches a predetermined value, the negative pressure in the filter unit 1 is released. At the same time when the used filter aid is peeled off from the plate surface of the filter plate 17, the clean liquid is supplied to the supply line 13. Normally, in this type of filtration device, when the filter aid is peeled off, the negative pressure in the filter unit 1 is released and the filtration is temporarily interrupted. Since the clean liquid can be supplied to the equipment using the clean liquid such as a machine tool while the filter aid is being peeled off, the supply of the clean liquid is not interrupted at all.

  On the other hand, an air cylinder 10 which is a unit swinging unit of the present invention is attached to the upper part of the filter unit 1 so that the filter unit 1 can swing up and down. When the deposited layer of the filter aid formed on the filter panel 5 is clogged and the pressure sensor 18 detects that the negative pressure in the pump communication path 9 and the filter unit 1 has reached a predetermined value, the electromagnetic on-off valve The valve 19 is opened to release the negative pressure in the filter unit 1, and at the same time, the air cylinder 10 is operated to swing the filter unit 1.

  By doing so, when the deposited layer of the filter aid is clogged and the negative pressure in the filter unit 1 reaches a predetermined value, the negative pressure in the filter unit 1 is automatically released and automatically Accordingly, the filter unit 1 is swung. Then, the release of the negative pressure in the filter unit 1 and the swinging of the filter unit 1 are performed simultaneously, and the filter plate 17 is used from the filter plate 17 of the filter unit 1 accommodated in the filtration tank so that the plate surface of the filter plate 17 faces sideways. The deposited layer of the filter aid already peels off and falls, and it takes no time to remove the deposited layer, and the interruption time of filtration accompanying the separation of the deposited layer is very short.

  Further, as shown in FIG. 4, a bubble discharge passage 28 for discharging air in the air pool generated in the filter unit 1 is connected to the upper portion of the filter unit 1 (in this example, the upper end portion of the cylindrical body 7). Has been. The bubble discharge path 28 is connected to an ejector device 27 as a gas suction means provided in the pump communication path 9.

  For example, as shown in FIG. 5, the ejector device 27 has a T-shaped flow path, and the clean liquid sucked from the filter unit 1 through the pump communication path 9 passes through the illustrated vertical flow path 30. It flows and is supplied to the machine tool etc. from the supply line 13, and the bubble discharge path 28 is connected to the branch path 31 branched in the illustrated horizontal direction. A tapered cylinder 32 is provided in the vicinity of the branch path 31 in the flow path 30 through which the clean liquid flows, which is a flow speed improving member that increases the flow speed of the clean liquid. Then, when the clean liquid passes through the cylindrical body 32, the flow velocity is increased, and the liquid flow applies a negative pressure in the branch path 31 and sucks the bubbles in the filter unit 1 from the bubble discharge path 28. Yes.

  As described above, since the air bubbles remaining inside the filter unit 1 are sucked and removed, the filtration efficiency is hardly lowered by the air bubbles remaining in the filter unit 1 as in the prior art. . In addition, there is almost no trouble that the deposited layer of the filter aid is not formed well due to the influence of bubbles remaining in the filter unit 1 or that the deposited layer is peeled off, so that stable filtration accuracy is maintained. Will be able to.

  The gas suction means is an ejector device 27 provided in the pump communication passage 9 to which a suction pump for sucking the liquid in the filter unit 1 is connected. The ejector device 27 and the upper portion of the filter unit 1 discharge bubbles. Since the connection is made through the passage 28, a negative pressure is applied to the bubble discharge passage 28 by the ejector device 27 using the liquid flow in the pump communication passage 9 generated by the suction pump 3 that sucks the liquid in the filter unit 1. The bubble can be sucked and removed by this negative pressure. As described above, since the negative pressure is generated using the flow of the liquid obtained by the suction pump 3, it is not necessary to separately provide power for sucking the bubbles, the equipment is simplified, and the energy efficiency is improved.

  Further, a pump communication path 9 is connected to the lower side of the filter unit 1, and a bubble discharge path 28 is connected to the upper side, which is the opposite side of the pump communication path 9. Therefore, the negative pressure generated by the ejector device 27 generated in the bubble discharge path 28 is not significantly affected by the suction force of the suction pump 3, and the bubbles staying in the upper part of the filter unit 1 can be sucked and discharged effectively. It can be done.

  The filtration device having the above configuration is operated as follows, for example.

  That is, first, the dirty liquid discharged from the machine tool or the like is introduced into the filtration tank 2 from the introduction line 11, and the filtration tank 2 is filled with the dirty liquid until the filter unit 1 is hidden under the liquid surface. On the other hand, in the slurry tank 4, a clean liquid and a filter aid are mixed at a predetermined mixing ratio in advance to generate a slurry.

  Here, the filter aid is not particularly limited as long as it is substantially powdery, and various kinds of filters can be used. For example, various materials such as diatomaceous earth, cellulose fiber, zeolite, activated carbon, silica gel, glass fiber, and ceramic fiber can be used. Among these, in particular, cellulose fibers are preferably used because they easily bridge on the mesh and easily entangle the filter aids, and a deposited layer is formed on the plate surface of the filter plate 17 very quickly. In the present invention, the “powdered shape” may be anything that can be mixed with a liquid to form a slurry, and the microscopic shape exhibits various shapes such as a fibrous shape, a lump shape, and a flake shape. It is intended to include things.

  Next, the slurry pump 14 is operated to supply the slurry in the slurry tank 4 to the vicinity of the filter plate 17 of the filter panel 5, and the suction pump 3 is operated to bring the inside of the filter unit 1 to a negative pressure. By this suction, the filter aid supplied as slurry is sucked together with the liquid into the punch holes 6 of the filter plate 17 and is deposited on the plate surface of the filter plate 17 (on the surface of the metal mesh 8). As described above, the filter aid supplied in the vicinity of the filter plate 17 is sucked and deposited by the negative pressure, so that the deposited layer is formed very quickly, and the interruption time of filtration accompanying the formation of the deposited layer is greatly shortened. At the same time, the reduction in filtration efficiency is prevented.

  When a deposited layer is formed to some extent, the supply of slurry is stopped and the operation of the suction pump 3 is continued. By this suction, the dirty liquid in the filtration tank 2 passes through the filter aid accumulation tank and is filtered. The filtered clean liquid is supplied from a supply line 13 to a machine tool or the like. In this way, filtration is continued continuously.

  Here, if foreign matter accumulates in the accumulation layer of the filter aid due to filtration and clogging occurs, the negative pressure in the filter unit 1 and the pump communication passage 9 increases. When the clogging progresses and the negative pressure reaches a predetermined value, the increase in the negative pressure is detected by the pressure sensor 18, and the electromagnetic on-off valve 19 is opened to release the negative pressure in the filter unit 1. At the same time, the air cylinder 10 is operated to swing the filter unit 1 up and down, whereby the accumulated layer of used filter aid is peeled off from the filter panel 5 and dropped onto the discharge conveyor 12. At this time, since the filter plate 17 on which the deposition layer of the filter aid is formed faces sideways, the used filter aid is easily peeled off and dropped, so that the filtration interruption time associated with the separation of the deposit layer is reduced. While greatly shortening, it prevents a decrease in filtration efficiency.

  Next, the slurry pump 14 is operated to supply the slurry in the slurry tank 4 to the vicinity of the filter plate 17 of the filter panel 5, thereby depositing a filter aid on the filter panel 5 to form a deposited layer, and repeated filtration I do. When forming this deposited layer, as described above, the filter aid supplied in the vicinity of the filter plate 17 is sucked and deposited by negative pressure, so that the deposited layer is formed very quickly. The interruption time of the accompanying filtration is significantly shortened, and a decrease in filtration efficiency is prevented.

  The used filter aid peeled off from the filter plate 17 falls on the discharge conveyor laid on the lower side of the filter unit 1 and operates the discharge conveyor 12 that has received the filter aid. The used filter aid on 12 is discharged from the filter tank 2.

  Here, the plurality of filter units 1 can release the negative pressure in the filter unit 1 substantially simultaneously and can be shaken to peel off the filter aids of the plurality of filter units 1 at the same time. By doing so, the filtration efficiency commensurate with the plurality of filter units 1 can be secured, and adverse effects on the lifetime of the deposited layer can be prevented.

  That is, since the filtration is not performed while the negative pressure in the filter unit 1 is released and the filter aid is peeled off, in order not to interrupt the supply of the clean liquid while peeling the filter aid. Conventionally, it has been necessary to release the filter aid by alternately or sequentially releasing the plurality of filter units 1 so as not to stop the filtration as a whole apparatus. As described above, when the plurality of filter units 1 are alternately or sequentially peeled off, the plurality of filter units 1 are stopped in order, so that the entire apparatus has a filtration efficiency corresponding to the number of filter units 1. Could not get. In addition, the used filter aid is sucked into the filter unit 1 adjacent to the filter unit 1 from which the filter aid is peeled off to shorten the life of the deposited layer, or vibration is transmitted to the adjacent filter unit 1 for deposition. It was a factor that peeled off.

  Therefore, as described above, by supplying the clean liquid to the supply line 13 simultaneously with the release of the negative pressure, the clean liquid is supplied to the clean liquid using equipment such as a machine tool while the filter aid is being peeled off. Since the supply of the clean liquid is not interrupted at all, the filter aids of the plurality of filter units 1 can be peeled and removed at the same time, and the filtration efficiency corresponding to the plurality of filter units 1 can be ensured. It is possible to prevent an adverse effect on the deposited layer of the adjacent filter unit 1. That is, if there are two filter units 1, it is possible to operate by always contributing to filtration with the filter area of two units.

  As described above, according to the filtration device, the filter aid supplied from the slurry tank 4 is sucked to the plate surface of the filter plate 17 of the filter panel 5 by the negative pressure in the filter unit 1 generated by the suction pump 3. Therefore, the deposited layer can be formed quickly, and the filtration is hardly interrupted as in the prior art. In addition, a high filtration accuracy with a removal rate of foreign matters of 10 μm or more being 95% or more could be secured.

  Further, since the filter unit 1 is provided with radial filter panels 5 having filter plates 17 on both sides on the peripheral wall of the cylindrical body 7, the effective area of the filter on which the filter aid is deposited is increased. Increases filtration efficiency.

  In the above embodiment, the shape of the filter unit 1 is exemplified by eight filter panels 5 arranged radially on the peripheral wall of the cylindrical body 7, but is not limited to this, and the filter panel 1 The number of 5 may be 7 or less, or 9 or more. Moreover, the cylindrical thing in which the surrounding wall became the filter board 17 may be sufficient, and the box-like thing in which the surrounding wall became the filter board 17 may be sufficient.

  Alternatively, the filtration tank 2 may be partitioned into a plurality by the filter plate 17, and one of the chambers may be sucked by the suction pump 3. Further, the number of filter units 1 is not limited to two, and may be one or three or more. Furthermore, in the said Example, although the bubble in a filter unit was attracted | sucked by the ejector apparatus 7, it is not limited to this, Various apparatuses are applicable if it can generate a negative pressure.

  The filtration device of the present invention is not only for filtering the cutting fluid of machine tools, but as the liquid to be filtered, various coolants such as rolling mills, boiler condensate, plating solution, beverages such as beer and fruit juice, etc. It is possible to apply to any liquid.

It is a block diagram which shows the filtration apparatus of one Example of this invention. It is a figure which shows a filter unit, (a) is a cross-sectional view, (b) is a front view. It is a figure which shows the periphery structure of a filter unit, (a) is a top view, (b) is a front view. It is AA sectional drawing of a filter unit, and a figure which shows the periphery structure. It is a figure which shows the structure of an ejector apparatus. It is a block diagram which shows the conventional filtration apparatus. It is sectional drawing which shows the inside of the filter chamber of the said filtration apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter unit 2 Filtration tank 3 Suction pump 4 Slurry tank 5 Filter panel 6 Punch hole 7 Cylindrical body 8 Metal mesh 9 Pump communication path 10 Air cylinder 11 Introduction line 12 Discharge conveyor 13 Supply line 14 Slurry pump 15 Slurry supply piping 16 Supply Pipe 17 Filter plate 18 Pressure sensor 19 Electromagnetic switching valve 20 Break tank 21 Flow switch 22 Electromagnetic switching valve 23 Flow switch 24 Electromagnetic switching valve 25 Auxiliary tank 26 Feeder 27 Ejector device 28 Bubble discharge path 29 Break path 30 Flow path 31 Branch path 32 Cylinder 33 Clean liquid replenishment path 34 Ring flow path 51 Filter tube 52 Filter chamber 53 Dirty tank 54 Clean tank 55 Filter pump 56 Diatomaceous earth supply feeder 57 Slurry tank 58 recovery tank 59 separator 60 slurry pump 61 precoat layer 62 punch holes 63 a metal mesh 64 dump valve 65 Valve 66 reject bin 67 bubbles

Claims (5)

  A filtration device for forming a particulate filter aid accumulation layer on a plate surface of a filter plate, and filtering the liquid with the accumulation layer, wherein the filter unit is a hollow filter unit provided with a filter plate on at least a part of the surface. A filter tank in which the liquid to be filtered is stored and the filter unit is accommodated, and the filter unit is accommodated in the filter tank so that the plate surface of the filter plate faces sideways, The filter aid is supplied to the vicinity of the plate surface, the liquid in the filter unit is sucked by the suction pump, and the air bubbles remaining inside from the upper part of the filter unit are sucked by the gas suction means. A filtration device characterized by that.   The gas suction means is an ejector device provided in a pump communication path to which a suction pump for sucking liquid in the filter unit is connected, and the ejector device and the upper part of the filter unit are connected by a bubble discharge path. The filtration device according to claim 1.   The downstream side of the pump communication path is a clean liquid supply line. When the negative pressure in the filter unit reaches a predetermined value, the clean liquid is supplied to the pump communication path, thereby The filtration apparatus according to claim 1 or 2, wherein the pressure is released and the used filter aid is separated from the plate surface of the filter plate, and at the same time, the clean liquid is supplied to the supply line.   When the negative pressure in the filter unit reaches a predetermined value, the negative pressure in the filter unit is released, and the filter unit is swung by the unit swinging means so that the used filter aid is removed from the filter plate. The filtration device according to claim 3, wherein the filtration device is adapted to drop from the plate surface. The filtration apparatus according to claim 3 or 4, comprising a plurality of filter units, wherein the plurality of filter units are configured to release negative pressure in the filter units substantially simultaneously.

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