CN220194177U - Self-flushing filtering device - Google Patents

Abstract

The utility model relates to a self-flushing filter device comprising: the tank body is provided with an inner wall defining a first channel extending along the vertical direction, a sewage outlet is arranged on the inner wall, and the sewage outlet comprises an inner peripheral wall; the filter screen plate is rotatably arranged in the first channel and comprises a top surface and a bottom surface, the top surface and the inner wall define a first cavity, and the bottom surface and the inner wall define a second cavity; the valve plate is rotatably arranged on the inner wall and comprises a step, and the step is provided with an outer peripheral wall; the self-flushing filtering device comprises a valve plate, a first chamber, a second chamber, a filter screen, a self-flushing filtering device, a valve plate, a first chamber and a drain outlet, wherein the outer peripheral wall is connected with the inner peripheral wall when the self-flushing filtering device is in a filtering state, the valve plate cuts off the second chamber and the drain outlet, the filter screen is abutted to the valve plate when the self-flushing filtering device is in a flushing state, the outer peripheral wall is not connected with the inner peripheral wall, and the first chamber is communicated with the drain outlet. The self-flushing filter device provided by the utility model can automatically flush the filter screen plate when the filter screen plate is blocked, and has low equipment manufacturing and maintenance cost.

Description

Self-flushing filtering device

Technical Field

The utility model relates to the field of environmental protection, in particular to a self-flushing filtering device.

Background

The self-cleaning filter is a precise device which directly intercepts impurities in water by utilizing a filter screen, removes suspended matters and particulate matters in water, reduces turbidity, purifies water quality, reduces system dirt, bacteria and algae, rust and the like, so as to purify water quality and protect other equipment of the system, water enters the self-cleaning filter body from a water inlet, and the system can automatically identify the deposition degree of the impurities due to the design of intellectualization (PLC and PAC), so that the signal of a sewage disposal valve is automatically and fully discharged.

Currently, automatic filters are mainly siphoned back flushing or water pump flushing. The siphon backflushing is that the inner layer impurities of a fine filter screen of the automatic flushing filter device are gradually accumulated, a pressure difference is gradually formed between the inner side and the outer side, a control valve is opened to control the sewage to be discharged after the pressure difference reaches a preset value, and a filter with the flow of 300m3/h is taken as an example: the back flushing flow is 35-40 m3/h, the back flushing time is 7-15 seconds, the back flushing water amount is 80-160L, the water source is wasted, in addition, the flushing by using a water pump also needs to be controlled, the flushing is complicated, the self-flushing filtering and water pump equipment has high cost, and periodic overhauling and maintenance are needed.

Disclosure of Invention

In view of the above, the present utility model aims to solve at least one of the technical problems in the related art to some extent.

To this end, an object of the present utility model is to propose a self-flushing filter device comprising: the tank body (10), the tank body (10) is provided with an inner wall (11) defining a first channel (103) extending along the vertical direction, a drain outlet (13) is arranged on the inner wall (11), and the drain outlet (13) comprises an inner peripheral wall (131); -a filter screen (20), the filter screen (20) being rotatably arranged within the first channel (103), the filter screen (20) comprising a top surface (21) and a bottom surface (22), the top surface (21) and the inner wall (11) defining a first chamber, the bottom surface and the inner wall defining a second chamber; and a valve plate (40), the valve plate (40) being rotatably provided on the inner wall (11), the valve plate (40) including a step (401), the step (401) having an outer peripheral wall (401 a); wherein, from washing filter equipment (100) when filtering the state, peripheral wall (401 a) with inner wall (131) are connected, valve plate (40) cut off second cavity (102) and drain (13), when washing the state, filter screen board (20) butt in valve plate (40), peripheral wall (401 a) not with inner wall (131) are connected, first cavity (101) with drain (13) switch on.

According to the utility model, the rotatable filter screen plate (20) is arranged in the tank body (10), suspended matters and particles in sewage are filtered by the filter screen plate (20), after sundries block the filter holes, the water injection quantity is larger than the water outlet quantity, a large amount of water is accumulated above the filter screen plate (20), the gravity born by the filter screen plate (20) is gradually increased to drive the filter screen plate (20) to rotate, the valve plate (40) is touched and opened in the rotation process of the filter screen plate (20), at the moment, the sewage drain (13) is communicated with the first chamber (103), the water on the filter screen plate (20) is discharged from the sewage drain (13), the sundries blocked in the filter holes are washed by water flow, the filter holes are turned on again, the filter screen plate (20) is restored to the initial position, and the device continues to filter the sewage until the sundries block the filter Kong Bingchong again, and the washing step is repeated.

Compared with the traditional self-flushing filter device, the self-flushing filter device provided by the utility model has the advantages that the self-weight of water flow accumulated on the filter screen plate (20) after the filter screen (20) plate is blocked drives the filter screen plate (20) to rotate and opens the valve plate (40) to flush the self-filtering holes, the device is ingenious in conception, simple in structure, low in manufacturing and maintenance cost and less in flushing water consumption, and water resources are saved.

In some embodiments, the inner wall (11) comprises a protruding portion (12) protruding along the horizontal direction, the protruding portion (12) comprises a curved surface section (121), the curved surface section (121) is provided with a top end (121 a) and a bottom end (121 b), the top end (121 a) is provided with a limiting block (14), the drain outlet (13) is arranged at the bottom end (121 b), the filter screen plate (20) is hinged with the inner wall (11) on the opposite side of the protruding portion (12), in the filtering state, the filter screen plate (20) is abutted to the limiting block (14), and the protruding portion is arranged to divide a first cavity () and a second cavity while realizing rotation of the filter screen plate (20), so that the filter screen plate is simple in structure and convenient to implement.

In some embodiments, the protrusion (12) further comprises a support section (122) extending in a horizontal direction and having a right end (122 ca), the right end (122 ca) is connected with the bottom end (121 b), the valve plate (40) is hinged on the support section (122), and the support section (122) is provided to hinge the valve plate (40), so that the valve plate (40) is advantageously arranged on a path of rotation of the filter screen plate (20), and the valve plate is opened when the filter screen plate (20) rotates.

In some embodiments, the support section (122) includes a first section (122 a), a second section (122 b) and a third section (122 c) that are sequentially connected, the third section (122 c) is connected with the bottom end (121 b), the first section (122 a) and the third section (122 c) are horizontally arranged, the second section (122 b) is obliquely arranged, the valve plate (40) is hinged on the third section (122 c), in the flushing state, the second section (122 b) is attached to and supports the valve plate (40), the structure of the support section (122) is further thinned, the corresponding structure matched with the valve plate (40) in the support section (122) is obliquely arranged, the travel of the valve plate (40) is limited, the valve plate (40) can be ensured to be completely opened, and the oblique arrangement is also beneficial to restoring the valve plate (40) to the position originally connected with the drain outlet (13).

In some embodiments, the filter screen comprises a first elastic piece (30), wherein two ends of the first elastic piece (30) are respectively connected with the tank body (10) and the filter screen plate (20), the elastic piece is connected with the filter screen plate and the tank body, the structure is simple, implementation is facilitated, connection is reliable, and economic cost is low.

In some embodiments, the tank body (10) further comprises a supporting portion (15) protruding towards the central portion of the first channel (103), the supporting portion (15) is located above the hinge of the filter screen plate (20) and the tank body (10), one end of the first elastic piece (30) is connected with the filter screen plate (20), the other end of the first elastic piece is connected with the supporting portion (15), the supporting portion (15) is arranged, the elastic piece (30) can be vertically arranged, the pulling force direction acting on the filter screen plate (20) is changed, pulling of the elastic piece (30) is facilitated, and the sensitivity and reliability of the device are improved.

In some embodiments, the device further comprises a second elastic member (50), one end of the second elastic member (50) is connected to a part below the drain outlet (13) of the tank body (10), the other end of the second elastic member is connected with the valve plate (40), and the elastic member (50) is connected with the valve plate (40) and the tank body (10), so that implementation is facilitated, connection is reliable, and manufacturing cost is low.

In some embodiments, the valve plate (40) includes a radially inwardly recessed notch (402) to facilitate interengagement with the filter screen plate during rotation of the filter screen plate and opening the valve plate to communicate the drain with the first chamber.

In some embodiments, the hinge between the inner wall (11) and the filter screen plate (20) protrudes outwards and defines a fourth chamber (104), the filter screen plate (20) and the inner wall (11) are hinged in the fourth chamber (104), and the hinge between the inner wall (11) and the filter screen plate (20) protrudes outwards, so that the filter screen plate (20) and the inner wall (11) are mutually attached, and the water leakage amount at the hinge is reduced.

In some embodiments, the device further comprises a purified water outlet (16) arranged at the bottom of the tank body (10), and the purified water outlet (16) is used for discharging filtered purified water.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

Additional features and advantages of the utility model are described in the following description, which explains the utility model in more detail based on embodiments with reference to the drawings.

Fig. 1 is a schematic view showing a structure of a self-flushing filtration device in a filtration state according to an embodiment of the present utility model.

Fig. 2 is a schematic view of a self-flushing filtration device according to an embodiment of the present utility model in a flushing state.

Fig. 3 is an enlarged view of the portion a.

Fig. 4 is an enlarged view of the C portion.

Reference numerals illustrate:

100-self-flushing the filter device;

10-a tank body, 101-a water storage chamber, 102-a clean water chamber, 103-a vertical channel, 104-a hinge chamber, 11-an inner wall, 12-a protruding part, 121-a curved surface section, 121 a-a top end, 121 b-a bottom end, 122-a supporting section, 122 a-a horizontal section, 122 b-an inclined section, 122 c-a horizontal section, 122 ca-a right end, 13-a drain outlet, 131-an inner peripheral wall, 14-a limit clip, 15-a supporting part and 16-a clean water outlet;

20-a filter screen plate, 21-a top surface and 22-a bottom surface;

30-an elastic member;

40-valve plate, 401-step, 401a peripheral wall, 402-notch;

50-an elastic member;

Detailed Description

Preferred embodiments of the present utility model will be described below with reference to the accompanying drawings. It should be noted that the terms "upper", "lower", "left", "right", "front", "rear" and the like are used herein for illustrative purposes only and are not limiting of the present utility model.

As shown in fig. 1, an embodiment of the present utility model provides a self-flushing filtration device 100. The self-flushing filtration device 100 includes: a tank 10, the tank 10 having an inner wall 11 defining a vertical passage 103 (as an example of a first passage) extending in a vertical direction, the inner wall 11 being provided with a drain 13 communicating with an outside of the tank and a purified water outlet 16 provided at a bottom of the tank 10, water with suspended matter being injected into the vertical passage 103 from above the tank 10, the drain 13 having an inner peripheral wall 131;

a filter screen 20, wherein a plurality of filter holes are formed on the filter screen 20, the filter screen 20 is rotatably arranged in the first channel 103 and comprises a top surface 21 and a bottom surface 22, the top surface 21 and the inner wall 11 define a water storage chamber 101 (as an example of a first chamber), the bottom surface 22 and the inner wall 11 define a clear water chamber 102 (as an example of a second chamber), water flow with suspended matters flows into the clear water chamber 102 from the filter holes after being injected into the vertical channel 103, and the suspended matters are filtered and blocked on the top surface 21 by the filter screen 20; and a valve plate 40, the valve plate 40 being rotatably provided on the inner wall 11, the valve plate 40 including a step 401, the step 401 having an outer peripheral wall 401a.

The self-flushing filter device 100 includes a filtering state in which the outer peripheral wall 401a is connected with the inner peripheral wall 131, the valve plate 40 blocks the clean water chamber 102 and the sewage outlet 13, and a flushing state in which the filter screen plate 20 is abutted to the valve plate 40 after rotating by gravity of accumulated water which cannot flow into the clean water chamber 102 after blocking the filter holes, and the outer peripheral wall 401a is not connected with the inner peripheral wall 131, and the water storage chamber 101 is communicated with the sewage outlet 13. When suspended matters in the water flow are filtered by the filter screen plate 20, suspended matters are intercepted on the top surface 21 and in the filter holes, the filter holes of the filter screen plate 20 are gradually blocked along with the increase of the suspended matters, the water passing efficiency of the filter screen plate 20 is gradually reduced until the water injection amount is larger than the water filtering amount of the filter screen plate, the accumulated water amount above the filter screen plate is gradually increased, the water in the water storage chamber 101 and the suspended matters on the top surface 21 are downwards pressed by the filter screen plate 20 under the action of gravity, the self-flushing filter device 100 is changed into a flushing state from the filtering state, the filter screen plate 20 is abutted to the valve plate 40 in the downwards moving process and drives the valve plate 40 to block the drain hole 13 from the filtering state to rotate to an open position, the water storage chamber 101 is communicated with the drain hole 13, the water in the water storage chamber 101 flows to the outside of the tank body 10 from the drain hole, the suspended matters accumulated on the top surface 21 also flows to the outside of the tank body under the flushing of the water flow, the suspended matters on the filter screen plate 21 are repeatedly conducted after the filter holes are completely flushed, and the water flow smoothly flows into the clean water chamber 102 from the water storage chamber 101.

As shown in fig. 1, the inner wall 11 includes a protruding portion 12, the protruding portion 12 includes a curved surface section 121, a cross section of the curved surface section 121 in a vertical direction is generally an arc, when the filter screen plate 20 rotates from a filtering state to a flushing state, the filter screen plate 20 is clung to the arc, a diameter of the arc is a distance from a hinge point of the filter screen plate and the inner wall to one end of the filter screen plate contacting the arc, a round point of the arc is a hinge point of the filter screen plate and the inner wall, and a limiting clip 14 is disposed on a top end 121a of the curved surface section 121, and the limiting clip 14 is used for limiting a position of the filter screen plate 20.

As shown in fig. 1, 2, 3 and 4, the protrusion 12 further includes a support section 122, the support section 122 extends in a horizontal direction and has a right end 122ca, the right end 122ca is connected to the bottom end 121b, the valve plate 40 is hinged to the support section 122, and in the filtering state, an outer circumferential wall 401a of the valve plate 40 is connected to an inner circumferential wall 131 of the drain 13, and the valve plate 40 seals the drain 13.

The support section 122 includes a horizontal section 122a (as a first section example), an inclined section 122b (as a second section example) and a horizontal section 122c (as a third section example) which are sequentially connected, the horizontal section 122c has a right end 122ca, the right end 122ca is connected with the bottom end 121b, the horizontal section 122a and the horizontal section 122c are horizontally arranged, the inclined section 122b is obliquely arranged, the valve plate is hinged on the horizontal section 122c, and in the flushing state, the inclined section 122b is attached to and supports the valve plate 40.

As shown in fig. 1 and 2, the self-flushing filter device 100 further includes an elastic member 30 (as an example of a first elastic member), one end of the elastic member 30 is connected to the tank 10, and the other end is connected to the filter screen plate 20, in this embodiment, the elastic member 30 applies an upward tensile force to the filter screen plate 20, the filter screen plate has a tendency to move upward under the action of the elastic member, after moving to the top end of the curved surface section 121, the filter screen plate is blocked by the limiting card 14 from continuing to move upward, the top surface and the bottom surface respectively define a water storage chamber and a clean water chamber with the inner wall, and the water storage chamber and the clean water chamber are communicated through the filter holes on the filter screen plate.

The tank body 10 is to the supporting part 15 that vertical passageway 103 outstanding is used for supporting the elastic component 30, and supporting part 15 sets up in the top of the pin joint of filter screen plate 20 and inner wall 11, and the other end of elastic component 30 sets up on supporting part 15, and the filter screen plate can be pulled along vertical direction to the elastic component 30, sets up so, and efficiency is higher when exerting the pulling force to the filter screen plate.

The self-flushing filter device further comprises an elastic member 50 (as an example of a second elastic member), one end of the elastic member 50 is connected with the bottom end 121b, the other end of the elastic member is connected with the valve plate 40, in this embodiment, the elastic member 50 applies a rightward pulling force to the valve plate 40, in a filtering state, the valve plate 40 is tightly connected with the drain 13 under the action of the pulling force of the elastic member 50, so as to realize blocking of the drain, further, the vertical channel 103 and the drain 13 are blocked, in a flushing state, accumulated water on the filter screen plate presses the filter screen plate against the valve plate under the action of gravity, the valve plate 40 is driven to overcome the pulling force of the elastic member 50, the valve plate 40 is lapped on the inclined section 122b, the water storage chamber 101 is communicated with the drain 13, and water flow and sundries in the vertical channel 103 can flow out of the drain 13.

As shown in fig. 3 and 4, in order to increase the tightness when the valve plate 40 is connected to the drain 13, the valve plate 40 protrudes outward beyond the step 401, and in the filtering state, the outer peripheral wall 401a of the step 401 is bonded to the inner peripheral wall 131 of the drain 13, thereby increasing the tightness when the valve plate is connected to the drain. The valve plate 40 is further provided with a notch 402 recessed inward along the radial direction of the valve plate, and the notch 402 receives the distal end of the filter screen plate when the filter screen plate 20 moves from the filtering state to the flushing state, so that the filter screen plate is facilitated to press down and open the valve plate.

As shown in fig. 1 and 2, the hinge portion between the inner wall 11 and the screen 20 protrudes outwards and defines a hinge chamber 104 (as an example of a fourth chamber), the screen 20 and the inner wall 11 are hinged in the hinge chamber 104, and the inner wall 11 protrudes outwards at the hinge portion between the inner wall 11 and the screen 20, so that the outer edge of the screen 20 except the hinge portion is attached to the inner wall 11, and the water leakage amount at the hinge portion is reduced.

Therefore, according to the self-flushing filtering device provided by the embodiment of the utility model, sewage is injected into the vertical channel from the upper part of the tank body, suspended matters and particulate matters in the water body are intercepted in the water storage chamber after the sewage is filtered by the filter screen plate, and filtered clean water flows out from the clean water outlet. As the debris on the filter screen plate top surface increases, the filtration pore is blocked gradually, the water passing efficiency of filter screen plate also reduces gradually, the water passing amount of filter screen plate also can reduce, after the filtration pore is blocked to a certain extent, the water filling amount in the jar body is greater than the water passing amount of filter screen plate, the water level in the vertical passageway will rise gradually, the gravity of the water that the filter screen plate bore also increases gradually, after the gravity that the filter screen plate bore is greater than the pulling force of elastic component 30, the filter screen plate that articulates on the inner wall takes place to rotate after overcoming the pulling force of elastic component 30 under the effect of gravity, until the filter screen plate butt on the valve plate, and overcome the pulling force of elastic component 50 and open the valve plate, drain and water storage room switch on this moment, the water flow in the water storage room flows out fast from the drain, the debris that blocks up the filter pore on the filter screen plate is washed out and flows to jar body outside along with the water flow, the gravity that the filter screen plate bore reduces and returns gradually under the pulling force of elastic component 30, after the filter screen plate bore is washed, can be recovered to initial state after the filter screen plate and the filter device resumes the filter state, the injection state from the filter device, the filter screen plate is recovered from the filter device has suspended solid and the filter material to pass through the filter screen plate, the filter screen plate is washed out from the water inlet repeatedly, the water passing through the filter screen plate has the filter particles and the filter medium volume is washed out from the top surface after the filter screen plate is washed out from the top surface is repeatedly.

The self-flushing filter device can automatically flush the filter plate, has low equipment manufacturing and maintenance cost and small water consumption, and can solve the problems of high equipment cost, water waste, need of using control elements, high equipment manufacturing and maintenance cost and inconvenient operation of the existing self-flushing filter device.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature. In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model.

In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, one skilled in the art can combine and combine the different embodiments or examples described in this specification.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the utility model.

Claims (10)

1. A self-flushing filtration device comprising:

the tank body (10), the tank body (10) is provided with an inner wall (11) defining a first channel (103) extending along the vertical direction, a drain outlet (13) is arranged on the inner wall (11), and the drain outlet (13) comprises an inner peripheral wall (131);

-a filter screen (20), the filter screen (20) being rotatably arranged within the first channel (103), the filter screen (20) comprising a top surface (21) and a bottom surface (22), the top surface (21) and the inner wall (11) defining a first chamber (101) and the bottom surface and the inner wall defining a second chamber (102); and

A valve plate (40), the valve plate (40) being rotatably provided on the inner wall (11), the valve plate (40) including a step (401), the step (401) having an outer peripheral wall (401 a);

wherein, from washing filter equipment (100) when filtering the state, peripheral wall (401 a) with inner wall (131) are connected, valve plate (40) cut off second cavity (102) and drain (13), when washing the state, filter screen board (20) butt in valve plate (40), peripheral wall (401 a) not with inner wall (131) are connected, first cavity (101) with drain (13) switch on.

2. Self-flushing filtration device according to claim 1, characterized in that the inner wall (11) comprises a protruding part (12) protruding in the horizontal direction, the protruding part (12) comprises a curved section (121), the curved section (121) has a top end (121 a) and a bottom end (121 b), the top end (121 a) is provided with a stopper (14), the drain outlet (13) is provided at the bottom end (121 b), the filter screen (20) is hinged to the inner wall (11) on the opposite side of the protruding part (12), and in the filter state, the filter screen (20) is abutted against the stopper (14).

3. The self-flushing filtration device according to claim 2, characterized in that the projection (12) further comprises a support section (122) extending in a horizontal direction and having a right end (122 ca), the right end (122 ca) being connected to the bottom end (121 b), the valve plate (40) being hinged on the support section (122).

4. A self-flushing filtration device according to claim 3, wherein the support section (122) comprises a first section (122 a), a second section (122 b) and a third section (122 c) connected in sequence, the third section (122 c) is connected to the bottom end (121 b), the first section (122 a) and the third section (122 c) are horizontally arranged, the second section (122 b) is obliquely arranged, the valve plate (40) is hinged to the third section (122 c), and in the flushing state, the second section (122 b) is attached to and supports the valve plate (40).

5. The self-flushing filtration device according to claim 4, comprising a first elastic member (30), wherein two ends of the first elastic member (30) are respectively connected to the tank (10) and the filter screen plate (20).

6. Self-flushing filtration device according to claim 5, characterized in that the tank (10) further comprises a support (15) protruding towards the central part of the first channel (103), the support (15) being located above the hinge of the screen (20) and the tank (10), the first elastic element (30) being connected at one end to the screen (20) and at the other end to the support (15).

7. The self-flushing filtration device of claim 6, further comprising a second elastic member (50), wherein one end of the second elastic member (50) is connected to a portion below the drain outlet (13) of the tank body (10), and the other end is connected to the valve plate (40).

8. The self-flushing filtration device of claim 2 wherein the valve plate (40) includes a radially inwardly recessed notch (402).

9. Self-flushing filtration device according to claim 2, characterized in that the hinge of the inner wall (11) with the screen (20) protrudes outwards and defines a fourth chamber (104), the screen (20) being hinged with the inner wall (11) within the fourth chamber (104).

10. The self-flushing filtration device of claim 2 further comprising a clean water outlet (16) disposed at the bottom of the tank (10).