JPS6233511A - Centrifugal self-cleaning filter apparatus - Google Patents

Abstract

PURPOSE:To improve the filtration efficiency of the titled apparatus and to prevent the rediffusion of foreign matter mixed in a liq. to be filtered into the liq. by providing a cylindrical filter of specified structure which is submerged in the liq. to be filtered and used, a rotor, a means for rotating the rotor, a sealing member and a dust collecting means. CONSTITUTION:A cylindrical filter A is connected to a pump, the filter A is submerged in a liq. to be filtered, the pump is started, rotors 3 and 4 are rotated, sealing members 14, 15, 17 and 18 are pressed on a rotating shaft part to seal the shaft, the pressure is maintained thereafter and filtration proceeds. Meanwhile, the filtrate present in the region between a blade 5 and the inner peripheral surface of the filter A is passed through the mesh of a filter medium 2 and again pushed back to the filter vessel 30 along with the rotation and due to the blade 5 which is embedded in the peripheral edge part of the rotors 3 and 4 at a specified setting angle. Consequently, the self cleaning of the filter A is performed. Moreover, the rediffusion of foreign matter mixed in the liq. to be filtered and which has been released from the surface of the filter medium 2 into the liq. is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a centrifugal self-cleaning filter device that can automatically remove mixed foreign matter in a fluid that tends to deposit on the surface of a filter medium during a filtration operation. .

[Prior Art] It is common practice in all industrial fields to simultaneously transport fluid and remove foreign matter mixed in the fluid by interposing a dust removal filter in the flow path of the fluid being pumped using a pump. It is widely practiced. This type of filter consists of a filter cloth wrapped around the outer circumferential surface of a rotating drum, a filter material stretched over a frame, or a short cylindrical wire mesh filter element with one end sealed. Those with a cartridge-type mounting base joined together have been used.

[Problems to be Solved by the Invention] In the conventional dust removal filter as described above, the smaller the particle size of the foreign matter mixed in the fluid to be filtered, the finer the filter medium is required. If there are many cases, il in a short period of time! Since foreign matter accumulates on the surface of the U and the filtration ability is significantly reduced, the cleaning operation of the filter must be repeated frequently, which involves a tremendous waste of time and labor, and is one of the causes of reduced productivity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a so-called self-cleaning filter that can be applied to a fluid source and is equipped with a mechanism for automatically removing foreign substances in a liquid to be filtered that tend to deposit on the surface of a filter medium during filtration work. .

[Means for Solving the Problems] In order to achieve the above object, the centrifugal self-cleaning filter device of the present invention has a filter medium attached to the peripheral wall surface of the hollow cylinder, and a cylinder shaft that communicates with the suction port of the pump. A cylindrical filter provided with a means, and a plurality of blades that rotate in contact with the inner circumferential surface of the cylindrical filter and have an angle to the inner circumferential surface in the direction of rotation. a rotary body, a rotating means for the rotary body, a sealing member provided on the cylindrical shaft portion for insulating the inner space of the cylindrical filter from outside air, and peeling from the surface of the filter medium by centrifugal force. and a dust collection means for preventing foreign matter mixed in the filtered liquid from being re-diffused into the liquid, and the cylindrical filter is used by being immersed in the filtered liquid. .

[Operation and Effects of the Invention] The communication means provided on the cylindrical shaft of the cylindrical filter is connected to the suction port of the pump via piping, and the filter is immersed in the liquid to be filtered to start the pump and at the same time, the rotating body is started. When it is rotated, the pressure inside the cylindrical filter is instantly reduced by the suction force of the pump, so the sealing member is pressed against the rotating shaft due to the pressure difference between the inside and outside of the cylindrical filter, and the shaft sealing state is maintained. From then on, this pressure difference is maintained and filtration progresses. On the other hand, as the blades, which are installed at a specific angle on the periphery of the rotating body, rotate along the inner circumferential surface of the cylindrical filter. The filtrate existing in the area sandwiched between the blade and the inner peripheral surface of the cylindrical filter is subjected to compressive force and centrifugal force by the blade, so it can be handled through the mesh of the filter medium and pushed back into the filtration tank. It will be done. At this time, the foreign matter in the liquid to be filtered that has been adsorbed by the mesh is pushed out from the mesh and falls off, allowing the filter to perform its self-cleaning action.

Therefore, the inconvenience of having to frequently wash the filter medium in order to remove the clogging of the filter medium that rapidly occurs during filtration operation, which is the case with conventional filtration devices, is eliminated, and the filtration efficiency is significantly improved.

[Example] The structure of the present invention will be specifically described below based on the example shown in the attached drawings.

In the explanatory diagrams of the first embodiment of the device according to the present invention shown in FIGS. 1 to 4, A is a cylindrical filter, and 1 is a casing of the cylindrical filter A, which has a closed inner space. If we consider ill material to be a semi-airtight material, it is a flat cylindrical body made of metal or synthetic resin. Reference numeral 1a denotes a group of vertically elongated slits provided at regular intervals on the peripheral wall surface of the filter casing 1, and the filter medium 2 is stretched across the slit-like openings. The filter medium 2 is a band-like body made of filter cloth or various mesh wire gauze, and is wrapped around the outer peripheral surface of the cylindrical filter. 3 and 4 are rotary bodies disposed in the inner space of the casing 1 of the cylindrical filter A, in contact with the top and bottom surfaces thereof, respectively; 7 is a rotating shaft of the disc-shaped rotary body 3; It is a hollow cylindrical body, and is fitted through a bearing 10 into a bearing cylinder 13 that serves as a means for communicating with a pump suction port formed in the cylinder shaft portion of the top wall surface of the casing 1 . Reference numeral 8 denotes a rotating shaft of the rotating body 4, which is also disk-shaped, and is fitted through a bearing ball 9 into a recessed seat provided in the cylindrical shaft portion of the bottom wall surface of the casing 1.

Reference numeral 5 denotes a plurality of blades that are attached to the opposing peripheral edges of the pair of upper and lower rotating bodies 3 and 4 so that the rack crosses over the blades, and has an arc shape in the width direction as shown in FIG. It forms a band-shaped plate, and its both ends are fixed to the rotating bodies 3 and 4 by bolts 6, respectively. Reference numeral 11 denotes a rotary boot for rotating the rotating shaft 7.

Reference numeral 12 denotes one end portion of a pipe inserted into the hollow rotating shaft 7 of the rotary body 3 and connected to the suction port of the pump. A flange-shaped portion 12a is formed. 20 is a bearing for supporting the pipe 12 within the hollow rotating shaft γ. Reference numerals 14 and 15 indicate a first opening for blocking the air gap communicating with the atmosphere between the hollow rotating shaft 7 and the pump pipe 12 inserted into the inner space of the casing 1. Seal members 17 and 18 are second sealing members for blocking the air gap between the bearing sleeve 13 and the rotating shaft 7 inserted into the inner space, which is in communication with the atmosphere, from the inner space of the casing 1. These two seal members are understood from FIG. 3, which is a partial view of the lower end and vicinity of the rotating shaft 1, and FIG. 4, which is a sectional view taken along line (B)-(B) of FIG. The outer seal member 15 (18) has the same structure as the inner seal member 14 (17), which has a structure in which two semi-cylindrical bodies made of rubber elastic material are combined to form a short cylinder. and are fitted together coaxially and with some distance between them so that their abutting points are angled at 90° from each other in the circumferential direction. 16 and 19
are retaining rings for fixing the first and second seal members, respectively.

The seal members 14 and 15 and 17 and 18 are both made of urethane rubber, fluorine rubber, etc., which have excellent elasticity and mechanical strength, especially wear resistance, and are normally shaped to form a vertical cylindrical wall surface. However, when the suction horn of the pump is applied into the casing 1 through the piping 12, the filter medium 2
Due to the ventilation resistance, the inner space of the casing 1 becomes depressurized with respect to the atmospheric pressure, and the seal members 14 and 15 are pushed by the atmospheric pressure and their inner diameters are expanded, so that the outer peripheral surface becomes the peripheral edge of the flange-shaped portion 12a of the pipe 12. By being pressed toward the inner circumferential surface of the rising portion 12b, it functions as a sealing member as described above. Similarly, seal members 17 and 18
The outer circumferential surface of the rotating body 3 fulfills its role by being pressed against the inner circumferential surface of the annular projection 3a formed on the top surface of the rotating body 3 by atmospheric pressure. 30 is a filtration tank incorporating a cylindrical filter A therein, and is provided with an inlet 30a and an outlet 30b for the liquid to be filtered.

FIG. 5 is a configuration diagram of a filtration system illustrating how to use the above-mentioned embodiment device, and 21 is a continuously variable speed motor or continuously variable transmission for rotating the rotating bodies 3 and 4 connected to the output shaft. 22 is a V-belt, 23 is a motor control box, 40 is a filtration pump, 31 is a liquid to be filtered, 32
is a discharge port pipe of the pump 40, 33 is a storage tank for filtered liquid,
34 is a pre-tank of the filtration tank 30, 35, 37 and 36
are piping and a liquid pump that connect the filtration tank 30 and the pre-tank 34.

Next, the operation of the above embodiment device will be explained.

Set up the apparatus as illustrated in FIG.
With the discharge valve (not shown in this figure) installed at the discharge port of the pump 40 in a closed state, the motor for driving the pump 40 is started, and at the same time, the continuously variable speed motor 21 for rotating the rotors 3 and 4 is started. Start at low speed. If the inside of the cylindrical filter A is not filled with filtrate and the mesh of the filter medium 2 is extremely fine, the inner space of the cylindrical filter A is filled with the filtrate in advance.

The ability of the filter medium 2 to remove foreign substances from the liquid to be filtered is improved when the foreign substances are deposited to some extent on the mesh of the filter medium 2 and the mesh is narrowed, so some amount of foreign substance deposition is rather preferable. After starting the device, the control device of the motor 21 is operated to direct the rotating bodies 3 and 4 in the direction shown by the arrow (c) in FIG. 2 and gradually increase the rotation speed. Since the blade 5 is installed in the section so as to be close to the inner circumferential surface of the casing 1 of the cylindrical filter, and at an installation angle that approaches the inner circumferential surface asymptotically,
Among the filtrate sucked into the casing 1 by the suction force of the pump 40, the filtrate existing in the wedge-shaped gap formed between the blade 5 and the inner wall surface of the casing 1 is indicated by an arrow (d). As the fluid is forced into this wedge-shaped gap, the fluid pressure increases.
Eventually, it is pushed out from the mesh of the filter medium 2 toward the outside of the casing 1, as indicated by the arrow. At this time, the foreign matter that was stuck in the mesh is also pushed out and falls out, so that the filter performs a self-cleaning action. If the rotation speed of the rotating body 3 increases further, the blade 5
Since the centrifugal force generated on the surface of the liquid is added to the pressing force of the liquid, the self-cleaning effect is further enhanced.

However, as mentioned above, it is desirable to allow some of the foreign matter to settle on the surface of the filter medium 2 to increase the foreign matter removal ability;
On the other hand, there is also a demand for more efficient filtration work, so while checking the amount of foreign matter remaining in the filtered liquid,
The amount of filtrate sucked into the casing 1 of the cylindrical filter and the amount discharged from the pump 40 are balanced by adjusting the rotation speed of the pump 40 and at the same time changing the opening degree of the discharge valve. If the discharge valve is opened too much, the filtrate cannot be replenished into the casing 1, and the pump 40 will idle.

After the optimum rotation speed of the rotating body 3 has been determined based on the balance between the filtration effect and the discharge amount, the operating state of the device is fixed at this determined rotation speed and the discharge valve opening as long as it is operated under the same conditions. If this is done, it is possible to continue stable filtration work without causing the inconvenience that foreign matter in the liquid to be filtered gradually accumulates on the surface of the filter medium 2 and the filtration efficiency decreases over time.

Next, using a test device having the configuration shown in the above example, some comparisons were made of changes over time in the filtration capacity (discharge amount) of the device when the rotating body 3 was rotated and when it was not rotated. The results of this experiment will be explained with reference to Table 1, which is a list of each experimental condition, and Figures 10 to 13, which are graphs showing the correlation between pump discharge amount and operating time obtained for each of these experiments. . In each graph, measured values from experiments conducted five times under the same conditions are plotted, and the distribution area of this plot is defined as a band-shaped diagonal area (A) to (
It was displayed as follows.

In Fig. 10, which shows the experimental results of No. 1 in Table 1, when the rotating body 3 was not rotated, the discharge amount continued to decrease immediately after the device was activated, as seen in the band graph (b). It decreased by half after about 4 minutes, and by 1/1 after 8 minutes.
The rotation speed of rotating body 3 is 200 rpm while the rotation speed has decreased to about 0.
When rotated at m, as shown in graph (A), there was no noticeable drop in the discharge amount even after 10 minutes, and the outstanding filtration performance of the device of the present invention can be clearly seen.

The second and third experiments used paper valves, which are much more likely to clog the filter medium 2 than the iron powder used as the foreign material in the first experiment, so the effect of the self-cleaning action of the filter medium 2 was evaluated. As is clear from Fig. 11 and Fig. 12, respectively, graphs (C) and (D) and (E) and (E) when the rotating body 3 is rotated and when it is not rotated have extremely large changes over time. The slopes of the downward curves are different.

The fourth experiment was conducted under the same test conditions as the third experiment, except for the rotation speed of the rotating body 3 and the discharge amount, in order to determine the correlation between the rotation speed and the filtration performance. As shown in Fig. 13, which summarizes the test results, when the rotation speed of the rotating body 3 is aoorpm, no noticeable decrease in filtration capacity is observed even after 10 minutes as seen in graph A, and 40
Graph B at 0 rpm is not much different from graph A. After 5 minutes of reaching graph D at ioorpm, the filtration performance drops to around 80% of what it was at the start of operation. It is shown that there is no comparison with the graph (g) when the rotation speed is zero. Of course, the optimum rotational speed of the rotating body 3 varies depending on the filtration conditions, but if several experimental results are taken into consideration, it is concluded that a very effective self-cleaning effect of the filter medium is produced in the range of 200 to 400 rpm. be understood. Of course, if the rotation speed is increased beyond that, it is expected that the performance will improve somewhat.

In the device of the first embodiment described above, there is no means for removing foreign matter mixed in the liquid to be filtered, which is peeled off from the surface of the filter medium and gradually accumulated in the filtration tank. A second embodiment of the apparatus equipped with a dust collecting means for removing foreign matter will be described with reference to FIGS. 6 to 9.

Reference numeral 50 denotes a dust collection case for preventing foreign matter in the liquid to be filtered removed from the surface of the filter medium 2 by the self-cleaning action of the rotary filter A from re-diffusion into the filter tank 30. It has the shape of an open cylindrical container, and on its inner peripheral surface are four liquid flow guide members 51 in the shape of screw blades having an arc length slightly shorter than the circumference 174.
are mounted diagonally downward at equal intervals in the circumferential direction.

The rotating body 1 is placed in a dust collection case 50 in a state surrounded by these liquid flow guide members 51, and a plurality of bottom holes 50a are provided on the bottom wall surface of the case 50 to discharge foreign matter that accumulates. It is being 50b is a flange-shaped portion formed on the outer circumferential surface of the case 50, and is a flange-shaped portion formed on the outer peripheral surface of the case 50, and is
It is fixed to the bottom plate 30d using bolts 53 while being engaged with the edge of the fitting hole of the case 50 drilled in the center of the case 50.

Reference numeral 55 denotes a rotary lid body fitted onto the hollow rotary shaft 7 so as to cover the open top surface of the dust collection case 50,
To prevent foreign matter accumulating in a dust collection case from flying upward. This rotary lid has an extremely flat inverted funnel shape, and its conical surface has many slits 5 in the radial direction.
5a is provided. As shown in FIG. 8, both side walls a of the slit 55a in the longitudinal direction are sloped upward in the direction of rotation of the rotary lid 55, so that as the lid 55 rotates, The liquid to be filtered, which is located outside the dust collection case 50 and in front of this slit 55a, will be collided with the slope a, and the liquid that has received the collision energy will turn into a downward flow along the slope. The dust is allowed to flow into the dust collection case 50. Therefore, due to the function of the slit-shaped opening 55a having such a liquid flow guide function, the filtration foreign matter that has gradually accumulated inside the case 50 floats up with the movement of the liquid, and is prevented from coming out of the dust collecting case 50. This prevents the inconvenience of leaking out and diffusing into the filtered liquid again.

Of the liquid to be filtered once sucked into the case 50, the member 2
The excess amount that has not passed through the mesh passes through the gap between the top periphery of the case 50 and the outer periphery of the rotary lid 55 and is returned to the free space within the filtration tank 30, but is accompanied by this reflux. The amount of foreign matter involved is small.

55 is a cylinder for mounting the rotary lid 55, and 56 is a mounting bolt.

Reference numeral 60 denotes a casing of a vertical screw conveyor for guiding foreign matter contained in the liquid to be filtered, which is peeled off from the surface of the filter medium 2 of the rotary filter A by centrifugal force and gradually accumulated in the dust collection case 50, to the outside of the device. It is. 61 is a built-in vertical screw, 62 is a screw 610
The rotating shaft, 63 and 64 are the upper ball bearing and lower bearing of the rotating shaft 62, respectively, 65 is a bolt for fixing the screw 61 to the rotating shaft 62, and 66 is the casing 60.
61 is a hollow bolt for suppressing and fixing the sealing material 66, and 69 is a base on which a driving motor for the screw 61 is mounted. The casing 60 has seven flange-shaped portions provided at its upper end that are coupled to the bottom surface of the dust collection case 50 with fixing bolts 68.

70 is a dust collection case 50 by a vertical screw conveyor.
This is the casing of a horizontal screw conveyor for horizontally transporting foreign matter discharged from the bottom of the conveyor, 71 is a built-in horizontal screw, and 72- is a screw 71.
, 73 is a bearing cylinder, 74 is a bearing, 75 is a shaft seal packing, and 76 is a hollow bolt for pressing and fixing the packing 75. The foreign matter introduction lower Oa of the conveyor casing 70 is connected to the bottom discharge port of the vertical conveyor casing 60. 77 is a rubber hose or piping for extending the discharge port fitted to the discharge lower 0b of the horizontal conveyor casing.

FIG. 9 is a configuration diagram of a filtration system illustrating the usage of the second embodiment device, in which 80 is a driving motor for a vertical screw conveyor, 81 is an operation control box for the motor 80, and 82
is a shaft coupling. 90 is a drive motor for the horizontal slurry 1 conveyor, 91 is an operation control box for the motor 90, and 92 is a shaft joint. Other symbols are the same as those described above.

[Brief explanation of the drawing]

1 to 5 are explanatory diagrams of a first embodiment of the device according to the present invention, in which FIG. 1 is a side sectional view of the device, and FIG. 2 is a first embodiment of the device.
(A)-(A) sectional view in the figure, Figure 3 is a partial view of Figure 1,
FIG. 4 is a sectional view taken along line (b)-(b) of FIG. 1, and FIG. 5 is an illustrative view of the usage status of the apparatus. 6 to 9 are explanatory diagrams of the second embodiment device,
FIG. 6 is a side sectional view of the device, and FIG. 7 is a (E)-(
e) sectional view; FIG. 8 is a partial top view of the rotary lid body and a cross-sectional view thereof; FIG. 10 to 13 show actual experimental data for determining the relativity between the presence or absence of rotation of the rotating bodies 3 and 4 and the filtration capacity for a test device having almost the same structure as the device of the first embodiment. In the figure A...Tubular filter 1...Casing of the cylindrical filter 2...Filtering medium 3.4...Rotating body 5.
...Blade 7...Hollow rotating shaft (communication means) 14.
15.17.18 Seal member 30 Filtration tank 50 Dust collection case 55 Rotating lid body 60.
70...Conveyor casing 40...Pump

Claims (1)

[Scope of Claims] 1) A cylindrical filter in which a filter medium is attached to the peripheral wall surface of a hollow cylindrical body and a means for communicating with the suction port of the pump is provided in the cylindrical shaft portion; a rotating body having a plurality of blades installed therein, the blades rotating in the direction of rotation and having a mounting angle that widens towards the inner circumferential surface in the direction of rotation; a rotating means for the rotating body; A sealing member provided on the cylindrical shaft portion to isolate the empty space from outside air, and a sealing member provided on the cylindrical shaft portion to prevent foreign matter in the liquid to be filtered separated from the surface of the filter medium by centrifugal force from being re-diffused into the liquid. 1. A centrifugal self-cleaning filter device, comprising: a dust collecting means for filtration, wherein the cylindrical filter is used by being immersed in a liquid to be filtered. 2) The sealing member is made of a short cylindrical body made of rubber elastic material that is fitted into the bearing of the rotating shaft, and is pressed against the rotating shaft by expanding the diameter of the cylinder due to the pressure difference. 2. The centrifugal self-cleaning filter device according to claim 1, wherein the centrifugal self-cleaning filter device is configured such that the air gap is closed by closing the air gap. 3) The dust collection means includes a cylindrical dust collection case provided surrounding the cylindrical filter, and a cylindrical dust collection case that is fitted onto the rotating shaft of the rotating body so as to cover the top opening of the dust collection case. A rotary lid body and a conveyor for discharging the mixed foreign matter connected to a bottom opening of the dust collection case, and the rotary lid body is configured to cause the liquid to be filtered to flow into the dust collection case. of,
The centrifugal self-cleaning filter device according to claim 1 or 2, characterized in that the centrifugal self-cleaning filter device is provided with an opening having a liquid flow guiding function.