Mobile sludge recovery and filtration system

Abstract

The present invention provides a mobile sludge recovery and filtration system that can move to each machine tool and recover and filter sludge with a particle size distribution, including fine sludge, from a tank. [Solution] A mobile sludge recovery and filtration device comprising a mobile cart 6, a pump 9 mounted on the mobile cart 6, at least one suction-side filter unit 7, 8 mounted on the mobile cart 6 and disposed on the suction side of the pump 9, and at least one discharge-side filter unit 11 mounted on the mobile cart 6 and disposed on the discharge side of the pump 9, wherein at least one suction-side filter unit 7, 8 is equipped with a surface filtration type filter element 7e, and at least one discharge-side filter unit 11 is equipped with a deep filtration type filter element 11c.

Description

Technical Field

[0001] The present invention relates to a movable sludge recovery and filtration device that sucks, recovers, separates, and filters fine sludge mixed in a coolant tank of a machine tool together with the coolant liquid, and returns the clarified liquid after filtration to the same coolant tank for reuse.

Background Art

[0002] In the coolant tank of a machine tool, sludge such as cutting chips, grinding chips, or abrasive powder of the workpiece carried in by the coolant liquid accumulates, and eventually induces clogging of the circulating coolant liquid during workpiece processing, causing problems in processing quality. Therefore, in order to remove these sludges, a sediment sludge scraping conveyor, a drum filter, and a solid-liquid separation device such as a cyclone, a filter, or a magnetic separator with a magnetic rotating rotor are provided at the upper part of the tank to recover floating fine sludge in the liquid and clarify the liquid. Measures have been taken so that the clarified coolant liquid passes through these devices and is reused in the machine tool body.

[0003] However, even with the above-mentioned devices, there is still floating fine sludge that cannot be completely recovered, and it gradually settles and accumulates in the tank over time. Therefore, it is regularly suction-cleaned by a vacuum truck and replaced with new coolant liquid.

[0004] One reason why suspended fine sludge cannot be completely recovered is that drum filters and scraping conveyors are suitable for recovering sludge with larger particle sizes (millimeters), but unsuitable for fine sludge. Cyclones are relatively inexpensive and compact, and have many examples of adoption, but theoretically, their collection and separation efficiency decreases when dealing with low-density, micron-sized fine sludge or viscous liquids. Consequently, coolant liquid mixed with unseparated fine sludge is returned to the machine tool. At the same time, from a practical standpoint, it has been pointed out that the sludge collected from the bottom of the cyclone is difficult to handle when discharged due to its liquid-mixed state. Magnetic separators, of course, only collect magnetic sludge and are undeniably unsuitable for sludge made of non-magnetic metals or non-metallic materials.

[0005] In recent years, the need for precision machining has increased, and consequently, the sludge generated during machining has become finer, leading to an increase in the proportion of fine sludge flowing into the coolant tank. Therefore, strengthening the coolant filtration system to recover and remove fine sludge approximately a few microns in size helps maintain the clarity of the coolant, which in turn helps resolve coolant clogging problems during workpiece machining and reduces replacement costs by extending the coolant's lifespan.

[0006] In recent years, in particular, machine tools have shifted from a centralized coolant system that bundles multiple machines together to individual coolant management where each machine tool uses a different type of coolant, in response to the need for multi-product production. As a result, existing machine tool users have come to desire a mobile sludge recovery device that can move to each target machine tool to collect and remove sludge from the tank and filter the liquid in order to maintain liquid cleanliness. Specific examples of such devices are shown in, for example, Patent Documents 1 to 3.

[0007] Patent Document 1 presents a recovery device with a simple structure in which a cylindrical wire mesh filter is provided on the pump suction side on a mobile trolley, the sludge liquid sucked from inside the tank is separated by the filter, the sludge is captured inside the filter, and the filtered liquid is returned to the tank.

[0008] Patent Document 2 discloses a series of circulating recovery and filtration devices in which a suction pump is installed on a mobile trolley, the suctioned sludge liquid from the pump is supplied to a cyclone, which is referred to here as a centrifuge, the supernatant liquid from the cyclone is passed through a tank equipped with magnetic adsorption magnet rods, and then sent to a filtration separation tank. The filtered liquid is then returned to the original tank by a pressure pump, also located on the mobile trolley.

[0009] Patent Document 3 proposes a coolant cleaning device in which a pump on a mobile trolley sucks up the settled sludge in the tank and simultaneously returns it to the tank, loosening and diffusing the settled sludge. Then, the sludge liquid is supplied to a magnetic separator of the magnetic rotating rotor type on the mobile trolley, where the sludge is captured and separated, and the clarified liquid is returned to the tank. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] International Publication No. WO2013 / 021410A1 [Patent Document 2] Japanese Patent Publication No. 2010-253619 [Patent Document 3] Registered Utility Model Publication No. 3037122 [Patent Document 4] Japanese Patent Publication No. 2022-132669 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] According to the mobile sludge recovery devices described in Patent Documents 1 to 3, it is possible to move to each machine tool to recover and remove sludge from the tank and then filter it. However, the particle size of the sludge varies greatly depending on the type of machine tool. Conventional mobile sludge recovery devices have the problem that fine sludge, which has been increasing in proportion in recent years, passes through the filter element and returns to the tank.

[0012] Patent Document 4 discloses a filtration device that uses a deep-filtration type filter element to filter coolant and lubricating oil used in machine tools. This filtration device can recover fine sludge of approximately 10 μm or less. However, since it is a stationary filtration device, it is not suitable for moving to each machine tool to collect and remove fine sludge from the tank.

[0013] This invention has been made in view of the above problems, and aims to provide a mobile sludge recovery and filtration device that can move to each machine tool and recover and filter sludge containing fine sludge from a tank. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides a mobile sludge recovery and filtration device for sucking and recovering sludge settled on the bottom of a tank or suspended in a liquid together with the liquid, collecting and separating the sludge from the sludge-containing liquid, and returning the treated liquid to the tank for reuse, comprising: a mobile trolley; a pump mounted on the mobile trolley; at least one suction-side filter unit mounted on the mobile trolley and disposed on the suction side of the pump; and at least one discharge-side filter unit mounted on the mobile trolley and disposed on the discharge side of the pump, wherein the at least one suction-side filter unit is equipped with a surface filtration type filter element, and the at least one discharge-side filter unit is equipped with a deep filtration type filter element. [Effects of the Invention]

[0015] According to the present invention, sludge containing fine sludge can be collected and filtered from the tank by moving to each machine tool. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic side view of a mobile sludge recovery and filtration apparatus according to the first embodiment of the present invention. [Figure 2]This is a pneumatic circuit diagram for pump drive of a mobile sludge recovery and filtration device according to an embodiment of the present invention. [Figure 3] This is a schematic side view of a mobile sludge recovery and filtration device according to a second embodiment of the present invention.

Embodiments for Carrying out the Invention

[0017] Hereinafter, a mobile sludge recovery and filtration device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the mobile sludge recovery and filtration device of the present invention can be embodied in various forms and is not limited to the embodiments described in the specification. This embodiment is provided with the intention of enabling those skilled in the art to fully understand the invention by sufficiently disclosing the specification. (First Embodiment)

[0018] As shown in FIG. 1, the sludge recovery and filtration device according to the first embodiment of the present invention includes a mobile cart 6, a pump 9 mounted on the mobile cart 6, at least one suction-side filter unit 7, 8 mounted on the mobile cart 6 and disposed on the suction side of the pump 9, and at least one discharge-side filter unit 11 mounted on the mobile cart 6 and disposed on the discharge side of the pump 9. The mobile cart 6 includes a frame 6a and casters 6b.

[0019] The at least one suction-side filter unit 7, 8 includes a first suction-side filter unit 7 and a second suction-side filter unit 8. The first suction-side filter unit 7 and the second suction-side filter unit 8 are arranged in series such that a liquid containing sludge (hereinafter referred to as sludge liquid) passes through the second suction-side filter unit 8 after passing through the first suction-side filter unit 7.

[0020] Inside the tank 1, two suction parts 2 and 3 are provided. One of the suction parts 2 and 3 is a suction pipe 2 for manually sucking the sediment sludge 5a deposited on the bottom surface of the tank 1, and the other is a sediment float suction unit 3 that settles near the bottom surface of the tank 1 and automatically sucks the sludge 5b floating in the sludge liquid.

[0021] The suction pipe 2 is a resin cylindrical pipe and is mainly used to suck and recover the sediment sludge 5a deposited on the bottom of the tank 1. The operator holds the suction pipe 2 and moves it, and sucks while breaking up the solidified sediment sludge 5a with the suction pipe 2. The tip port of the suction pipe 2 is cut obliquely so that it is easy to break up the sediment sludge 5a and easy to perform the suction operation. A cock 2a is provided as a flow rate adjustment valve in the suction path (the path including the hose 2c) from the suction pipe 2. The operator adjusts the opening degree of the cock 2a at hand of the suction pipe 2 and manually controls the suction flow rate.

[0022] The sediment float suction unit 3 sinks to the surface of the sediment sludge 5a but stands on its own by the buoyancy of the float 3a, and the suction part 3b is always held in an upward-facing state. The buoyancy of the float 3a overcomes the total self-weight of the sediment float suction unit 3 and the nearby hose 3c connected thereto, but is not enough to float to the liquid surface. The sediment float suction unit 3 waits for the floating fine sludge 5b slowly sinking in the sludge liquid and efficiently sucks and recovers it. The sediment float suction unit 3 does not require manual operation and can be left in the sludge liquid. An upper cover cock 7d is provided as a flow rate adjustment valve in the suction path (including the hose 3c) from the sediment float suction unit 3.

[0023] There are two methods for suction recovery of sludge in tank 1. The method using suction pipe 2 is as described above. The method using the sedimentation float suction unit 3 involves an operator quickly recovering most of the settled sludge 5a using suction pipe 2, followed by unattended operation to recover suspended fine sludge 5b for a relatively long period of time. This is often done to maintain the clarity of the coolant liquid 4 in tank 1. In this case, the manual cock 2a of suction pipe 2 is closed. It is also acceptable to use suction recovery using both suction pipe 2 and the sedimentation float suction unit 3 simultaneously.

[0024] The casings 7b, 8b and top covers 7a, 8a of the first and second suction-side filter units 7, 8 mounted on the mobile trolley 6 are identical in structure. The roughly cylindrical casings 7b, 8b are fixed to the mobile trolley 6. Detachable top covers 7a, 8a are attached to the top of the casings 7b, 8b. Ring-shaped receiving seats 7c, 8c are fixed to the upper inner surface of the casings 7b, 8b.

[0025] The casing 7b holds the upper flange of a substantially cylindrical filter element 7e, which has a bottom. The top cover 7a is provided with a sludge liquid inlet via hose 2c and a sludge liquid inlet via hose 3c. A cock 7d is provided at the sludge liquid inlet via hose 3c, allowing the flow rate from the sedimentation float suction unit 3 to be adjusted.

[0026] The casing 8b holds the substantially cylindrical filter element 8e, which has a bottom, by receiving its upper flange. The top cover 8a is provided with a sludge liquid inlet via the hose 7g, as well as a cock 8d for air intake. When replacing the filter cloth bag filter 8e2, which will be described later, open this cock 8d.

[0027] Filter elements 7e and 8e are surface filtration types, and wire mesh filters, perforated metal filters, and filter cloth bag filters can be used as appropriate, taking into account the required filtration accuracy. If both filter elements 7e and 8e are wire mesh filters, and filter element 8e has a larger mesh size than filter element 7e, the opening of filter element 8e will be smaller than that of filter element 7e, allowing filter element 8e to capture finer sludge than filter element 7e. For capturing machine tool coolant sludge, mesh sizes #20 to #200 are generally used, and by using two wire mesh filters with different mesh sizes, it is possible to recover sludge down to approximately 50 to 100 μm. Wire mesh filters can be reused repeatedly.

[0028] In this embodiment, the focus is on capturing and separating fine sludge suspended in the sludge liquid and filtering the sludge liquid; therefore, the use of a filter cloth bag filter 8e2 as the filter element 8e is assumed. As shown in the figure, a perforated metal filter 8e1 is used in combination with the filter cloth bag filter 8e2 as the outer casing. This perforated metal filter 8e1 is not used for filtering purposes. Because the captured sludge accumulates inside the filter cloth bag filter 8e2 due to the suction negative pressure of the pump 9, without the perforated metal filter 8e1, the filter cloth bag filter 8e2 itself would expand, making it impossible to remove even if the top lid 8a is opened. There are various materials and nominal filtration sizes for the filter cloth bag filter 8e2, but in this embodiment, for practical purposes, a filter cloth bag filter 8e2 suitable for recovering sludge of 10 to 50 μm is used. Depending on the material, if the filter cloth bag filter 8e2 is made of synthetic fiber, it can be washed and reused several times, although this is troublesome.

[0029] The pump 9 mounted on the mobile trolley 6 is compressed air driven, and the compressed air system will be described later. In any case, the suction pressure of the pump 9 draws the sludge liquid in the tank 1 through the suction pipe 2 and the sedimentation float suction unit 3, flows into the first suction-side filter unit 7 for filtration, then flows again into the second suction-side filter unit 8 for filtration, is pressurized by the pump 9, and enters the liquid direction switching valve 10 (three-way valve). Reference numeral 9a is the suction port of the pump 9, and reference numeral 9b is the discharge port of the pump 9. Reference numeral 10c is the hose. At this stage, fine sludge of a few microns or less that could not be captured by the second filter element 8e is mixed into the sludge liquid. If a more clarified filtrate is required, the liquid direction switching valve 10 directs it to the discharge-side filter unit 11 via hose 10c. Otherwise, the liquid direction switching valve 10 returns it to the tank 1 via tank return hose 10b.

[0030] The discharge-side filter unit 11 has its top cover 11a fixed to the mobile trolley 6, and its casing 11b is screw-on and detachable from the top cover 11a. A deep-filtration type filter element, a wound cylindrical cartridge filter element 11c, is inserted into the casing 11b. During use, fine sludge is captured from the outer circumference of the filter element 11c towards the inside, and the clarified coolant liquid 4 is returned to the tank 1 via the tank return hose 11d from inside the cylindrical part of the filter element 11c. As the deep-filtration type filter element 11c captures sludge particles, clogging progresses, and as the filtration resistance pressure increases, a blockage phenomenon occurs, preventing the sludge liquid to be filtered from passing through the filter element 11c, requiring replacement. Although a filter element 11c that is clogged with sludge can be washed and reused, it is often discarded from a cost perspective.

[0031] As described in this embodiment, by making maximum use of the suction pressure of the pump 9 and performing a two-stage separation filtration using surface filtration type suction-side filter units 7 and 8 as a preliminary step to the discharge-side filter unit 11, the filtration load on the discharge-side filter unit 11 is reduced, which in turn extends the time until blockage occurs and reduces the frequency of replacement of the filter element 11c.

[0032] Furthermore, within the limits of the physical space available on the mobile trolley 6, if the number of discharge-side filter units 11 is increased, specifically by connecting a total of two units in parallel for practical purposes, a reduction in the filtration load per unit and a reduction in the frequency of replacement can be expected.

[0033] The sludge captured and collected in the filter elements 7e and 8e of the first and second suction-side filter units 7 and 8 needs to be removed and discharged as appropriate. However, according to this embodiment, the sludge can be dewatered using the following simple method, avoiding problems such as leakage and flooding of the surrounding area during removal. With the first top cover 7a removed and the second top cover 8a attached, the pump 9 is operated for several minutes. The suction air from the outside passes through the sludge layer in the first filter element 7e to dewater it, and then passes through the sludge layer in the second filter element 8e to dewater it as well. The air pressurized via the pump 9 also has the effect of pushing out the sludge liquid remaining in the third filter element 11c, which eliminates the need for a drain cock for replacing the third filter element 11c.

[0034] In the compressed air circuit diagram shown in Figure 2, the compressed air used to drive the pump 9 is maintained at a constant pressure by the air regulator 12, and therefore the pump's suction fluid flow rate is proportional to the supplied compressed air flow rate. When a large suction fluid flow rate is desired, such as during manual suction operation using the suction pipe 2 in Figure 1, the compressed air direction switching valve 14 is switched to allow the compressed air to pass through the manual operation circuit 14a, which has no intermediate valves or other restrictors. On the other hand, when using automatic suction operation with the sedimentation float suction unit 3, a very large suction fluid flow rate is not required. Therefore, the compressed air direction switching valve 14 is switched to send compressed air to the pump from the automatic operation circuit 14b, which has a needle valve 15 with a pre-restricted opening. Thus, to supply the pump 9 with a compressed air flow rate suitable for manual suction and automatic suction, there are separate circuits 14a and 14b that supply air via different routes, and one can be selected with a simple switching operation. Reference numeral 13 denotes the main valve.

[0035] The configuration of the mobile sludge recovery and filtration apparatus of this embodiment has been described above. The mobile sludge recovery and filtration apparatus of this embodiment provides the following effects. The system includes at least one suction-side filter unit 7,8 mounted on a mobile trolley 6 and positioned on the suction side of the pump 9, and at least one discharge-side filter unit 11 mounted on the mobile trolley 6 and positioned on the discharge side of the pump 9. Since at least one suction-side filter unit 7,8 is equipped with surface filtration type filter elements 7e,8e, and at least one discharge-side filter unit 11 is equipped with a deep filtration type filter element 11c, the system can be moved for each machine tool to collect and filter sludge containing fine sludge from the tank 1.

[0036] Since it is equipped with a first suction-side filter unit 7 and a second suction-side filter unit 8 arranged in series, it can recover coarse and medium-sized sludge.

[0037] Since the filter element 7e of the first suction-side filter unit 7 is a wire mesh filter, and the filter element 8e of the second suction-side filter unit 8 is a wire mesh filter or a filter cloth bag filter 8e2 with a finer mesh opening than the wire mesh filter of the first suction-side filter unit 7, it is possible to recover coarse and medium-sized sludge, for example, 50-100 μm or 10-100 μm.

[0038] Since a suction tube 2 and a sedimentation float suction unit 3 are provided, after an operator has recovered most of the settled sludge 5a using the suction tube 2 in a short time, the suspended fine sludge 5b can be recovered unattended using the sedimentation float suction unit 3.

[0039] Since flow control valves 2a and 7d are provided in both the suction path from the suction tube 2 and the suction path from the sedimentation float suction unit 3, the flow rate of the sludge liquid being aspirated can be adjusted.

[0040] If a highly clarified filtrate is required, the liquid direction switching valve 10 can direct the sludge liquid to the discharge-side filter unit 11; otherwise, the liquid direction switching valve 10 can return the sludge liquid to the tank 1.

[0041] The compressed air circuit for driving the pump is equipped with a compressed air direction switching valve 14 that selects either a manual operation circuit 14a or an automatic operation circuit 14b with pre-adjusted valve openings, thus eliminating the need to adjust the opening of the needle valve 15 during automatic operation. (Second Embodiment)

[0042] Figure 3 shows a schematic side view of a sludge recovery and filtration device according to a second embodiment of the present invention. The sludge recovery and filtration device according to the second embodiment, like the sludge recovery and filtration device according to the first embodiment, comprises a mobile trolley 6, a pump 9 mounted on the mobile trolley 6, suction-side filter units 7 and 8 mounted on the mobile trolley 6 and disposed on the suction side of the pump 9, and a discharge-side filter unit 11 mounted on the mobile trolley 6 and disposed on the discharge side of the pump 9. The configurations of the mobile trolley 6, pump 9, suction-side filter units 7 and 8, and discharge-side filter unit 11 are the same as those of the sludge recovery and filtration device according to the first embodiment, so the same reference numerals are used and their descriptions are omitted.

[0043] In the sludge recovery filtration apparatus according to the second embodiment, an ultrafine bubble generator 16 is provided downstream of the discharge-side filter unit 11. Although Figure 3 shows an example where the ultrafine bubble generator 16 is separated from the mobile trolley 6, in reality it is placed on or fixed to the mobile trolley 6. One-touch couplers are attached to both ends of the ultrafine bubble generator 16 for one-touch connection to the hose 11d.

[0044] When pressurized liquid from pump 9 is supplied to ultrafine bubble generator 16 via discharge-side filter unit 11, the ultrafine bubble generator 16 generates ultrafine bubbles (hereinafter referred to as UFB) in the liquid. UFB is a designation for fine bubbles with a diameter of 1 μm or less, and is defined in ISO20480-1 and JIS B8741-1:2019. The method by which the ultrafine bubble generator 16 generates UFB may be a high-speed swirling liquid flow method, a pressurized dissolution method, an ultrasonic cavitation method, etc.

[0045] The sludge recovery filtration apparatus according to the second embodiment provides the following functions and effects. The UFB generated by the ultrafine bubble generator 16 is supplied to tank 1 along with the liquid. Then, it circulates again through the circulation system (suction-side filter units 7, 8, pump 9, discharge-side filter unit 11, tank 1).

[0046] UFB is said to improve penetration (cooling performance) and cleaning effect when added to a liquid. By circulating a liquid containing UFB through a machine tool and using it as a coolant for grinding, cutting, etc., it is possible to improve the dimensional accuracy of the workpiece and extend the life of the tool. If the coolant tank of a machine tool is divided into a dirty tank and a clean tank, and the coolant from the clean tank is returned to the machine tool, a sludge recovery filtration system is used to filter the coolant from the clean tank, and UFB is added to the coolant from the clean tank.

[0047] The ultrafine bubble generator 16 is supplied with treated liquid from which fine sludge has been removed by the discharge-side filter unit 11. This prevents the ultrafine bubble generator 16 from becoming clogged.

[0048] Even if the ultrafine bubble generator 16 becomes clogged, the pump 9 is pneumatically driven, so the flow rate of the pump 9 will naturally decrease and it will stop. The pressure of the ultrafine bubble generator 16 will never exceed the pneumatic pressure of the pump 9, thus enabling fail-safe operation for both the ultrafine bubble generator 16 and the pump 9.

[0049] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of its essence. For example, the number of suction-side filter units may be one or three or more. Either a suction tube or a sedimentation float suction unit may be provided in the tank. The pump may be an electric pump. [Industrial applicability]

[0050] Beyond filtering machine tool coolants, this technology efficiently recovers fine foreign matter from liquids, purifying them and contributing to improved quality in other industries by purifying liquids in circulation tanks between manufacturing processes. [Explanation of Symbols]

[0051] 1... Tank 2...Suction tube 2a... Cock (flow control valve) 2c...Hose 3…Sinking float suction unit 3c...Hose 4…Coolant fluid (liquid) 5a, 5b... Sludge 6… Mobile cart 7…First suction side filter unit 7a... Detachable top cover 7d... Cock (flow control valve) 7e... Surface filtration type filter element 8…Second suction side filter unit 8e... Surface filtration type filter element 8e2…Cloth bag filter 9... Pump 10… Liquid direction switching valve 11…Discharge side filter unit 11c... Deep filtration type filter element 14… Compressed air directional switching valve 14a... Circuit for manual operation 14b...Automatic driving circuit 16…Ultrafine bubble generator

Claims

1. A mobile sludge recovery and filtration device for collecting sludge settled at the bottom of a tank or suspended in a liquid by suction along with the liquid, collecting and separating the sludge from the sludge-containing liquid, and returning the treated liquid to the tank for reuse, Mobile cart and A pump mounted on the aforementioned mobile trolley, At least one suction-side filter unit mounted on the aforementioned mobile trolley and disposed on the suction side of the pump, The system comprises at least one discharge-side filter unit mounted on the mobile trolley and disposed on the discharge side of the pump, The at least one suction-side filter unit comprises a surface filtration type filter element, A mobile sludge recovery filtration device in which at least one discharge-side filter unit is equipped with a deep-filtration type filter element.

2. The at least one suction-side filter unit comprises a first suction-side filter unit and a second suction-side filter unit, The mobile sludge recovery and filtration apparatus according to claim 1, characterized in that the first suction-side filter unit and the second suction-side filter unit are arranged in series such that a liquid containing sludge passes through the first suction-side filter unit and then through the second suction-side filter unit.

3. The filter element of the first suction-side filter unit is a wire mesh filter. The mobile sludge recovery filtration apparatus according to claim 2, characterized in that the filter element of the second suction-side filter unit is a wire mesh filter or a filter cloth bag filter with a finer mesh opening than the wire mesh filter.

4. A mobile sludge recovery and filtration apparatus according to any one of claims 1 to 3, characterized by comprising a suction pipe for manually sucking up sludge settled on the bottom of the tank, and a settling float suction unit that settles and stands on its own near the bottom of the tank, automatically sucking up sludge suspended in the liquid.

5. The at least one suction-side filter unit has a removable top cover having an inlet from the suction tube and an inlet from the sedimentation float suction unit. The mobile sludge recovery and filtration apparatus according to claim 4, characterized in that flow rate control valves are provided in both the intermediate suction path from the suction pipe and the intermediate suction path from the sedimentation float suction unit.

6. The mobile sludge recovery and filtration apparatus according to any one of claims 1 to 3, characterized in that a liquid direction switching valve is provided to select whether to send the liquid filtered by the at least one suction-side filter unit to the at least one discharge-side filter unit for further precision filtration or to return it to the tank after pressurizing the liquid with the pump, and then sending it to the at least one discharge-side filter unit for further precision filtration or returning it to the tank.

7. The mobile sludge recovery and filtration apparatus according to any one of claims 1 to 3, characterized in that the compressed air circuit for driving the pump is provided with a compressed air direction switching valve that selects either a manual operation circuit or an automatic operation circuit with a pre-adjusted valve opening.

8. The mobile sludge recovery and filtration apparatus according to any one of claims 1 to 3, characterized in that an ultrafine bubble generator is provided downstream of at least one discharge-side filter unit.

9. The mobile sludge recovery and filtration apparatus according to claim 8, characterized in that the pump is a compressed air-driven pump.

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