CN109939480B

CN109939480B - Back flush filter

Info

Publication number: CN109939480B
Application number: CN201810213233.8A
Authority: CN
Inventors: W.赫金
Original assignee: Hans Sasserath GmbH and Co KG
Current assignee: Hans Sasserath GmbH and Co KG
Priority date: 2017-12-20
Filing date: 2018-03-08
Publication date: 2021-09-14
Anticipated expiration: 2038-03-08
Also published as: CN109939480A; DE202017107783U1

Abstract

The invention relates to a backflush filter, in particular a backflush filter for filtering drinking or non-drinking water, which backflush filter can be switched from an operating position in which water is guided from an inlet through the filter to an outlet into a backflush position in which water can be guided from the inlet in the opposite direction through the filter to an outlet for backflushing, comprising: a housing (12, 20) with an inlet portion (14) and an outlet portion (16); a filter cup (30) arranged at the housing (12, 20) with a closable discharge; a substantially cylindrically configured filter element (44) which is guided axially movably between a first stop and a second stop.

Description

Back flush filter

Technical Field

The invention relates to a backflush filter for filtering drinking or non-drinking water, which backflush filter can be switched from an operating position in which water is guided from an inlet through the filter to an outlet into a backflush position in which water can be guided from the inlet in the opposite direction through the filter to an outlet for backflushing, comprising:

a backflush filter for filtering drinking or non-drinking water, the backflush filter being switchable from an operating position in which water is directed from an inlet portion through the filter to an outlet portion, into a backflush position in which water is directed from the inlet portion in the opposite direction through the filter to an outlet portion, for backflushing, the backflush filter comprising:

(a) a housing with an inlet and an outlet;

(b) a filter cup disposed at the housing, the filter cup having a closable drain;

(c) a substantially cylindrically configured filter element which is guided axially movably between a first stop and a second stop and which is arranged in the filter cup in such a way that an annular space which can be connected to the inlet is formed between the filter element and the filter cup and the filter element is closed off at the bottom;

(d) an annular projection on the outside of the filter element, which cooperates with a shoulder on the inner wall of the filter cup in such a way that

(i) A first connection from the entry to the outer annular space being open in a first position of the filter element and blocked in a second position of the filter element (blockier); and

(ii) a second connection from the access point to the interior of the filter element is blocked in the first position of the filter element and is open in the second position of the filter element.

Background

Water filters are used to filter potable or non-potable water. In this case, dirt particles become trapped in the filter material. Over time, the filter material is incorporated. Less or no water at all then passes through the filter. That is to say that the filter needs to be cleaned or renewed regularly. There are filters with filter material that is completely replaced. In the case of backwashing the filter, the flow through the filter material is periodically reversed. The dirt particles in the filter material are then entrained by the flow and the backwash water is removed via a drain.

EP 1688170B 1 by the applicant discloses a backflush filter in which two filters are arranged. The first filter is used for filtering the water in the operating position and the second filter is used for filtering the water arranged for backwashing.

DE 102009003343 a1 by the applicant discloses a filter assembly with a backflush filter arranged in a filter cup. The filter has a drain at the end below the filter cup, which drain is closed with a bulb (Kugelhahn). When the ball is open, a pressure difference occurs, by means of which the filter assembly is moved hydraulically into the backflush position. The assembly requires a plurality of annular spaces which can only be realized with a large diameter of the filter cup.

DE 202016103116U 1, DE 202009013661U 1, CN 106178647 a and CN 102485309 a disclose different backflush filters. The backwash water is conducted through the channel in the axial direction downwards. In this case, an increased flow speed is achieved in the region of the filter element, at which dirt is detached. The filter element or the channel must be rotated by hand in order to sweep the entire angular range of the filter element. The channel gives rise to a large diameter of the assembly. Automatic or semi-automatic backwashing is not possible or only possible with great expenditure by means of the assembly.

EP 3213803 a1 discloses a hydraulically actuatable filter assembly with a propeller (Impeller) inside the filter element and a ball for closing the discharge. The filter assembly includes a plurality of coaxial annular spaces. The filter assembly is of complex construction, has a large number of structural components and has large dimensions.

Disclosure of Invention

The object of the invention is to provide an elongated, simple-to-construct backflushing filter which can be moved hydraulically from an operating position into a backflushing position.

According to the invention, the object is achieved with a backflushing filter of the type mentioned at the outset, which is characterized in that,

(e) the filter element is provided with a seal at the end on the bottom side, and

(f) the inner wall of the filter cup is contoured such that

(i) A seal at the bottom-side end of the filter element in the first position bears sealingly against an inner wall of the filter cup and closes the annular space; and

(ii) in the second position, an intermediate space is formed between the sealing element and the inner wall portion of the filter cup, through which intermediate space water and possibly dirt particles can pass from the outer annular space to the discharge.

In the first position, that is to say in the operating position, the bottom region between the bottom of the filter element and the cup bottom is completely separated hydraulically from the annular space surrounding the filter element. That is to say that the pressure drop at the time of opening the discharge acts completely on the bottom of the filter element and pulls the filter element downward (zieht) into the backflush position. This is the second position. In this position, the filter cup has a slightly larger inner diameter, so that an intermediate space arises between the seal and the inner wall section of the filter cup. The filter cup can, for example, have a slot, slit or outward bow. The water and, if possible, dirt particles can then flow directly from the annular space surrounding the filter element to the open drain. No additional rings, adapters or spacers are required in the present invention.

Preferably, the filter element has a first filter section and a second filter section and an annular projection on the outside of the filter element between the first filter section and the second filter section for separating the outer annular space from a region outside the first filter section, wherein the annular projection interacts with a shoulder on an inner wall of the filter cup in such a way that the annular projection interacts with the shoulder on the inner wall of the filter cup in such a way that the first filter section and the second filter section are separated by the annular projection

(a) A connection from the access to the outer annular space is open in a first position of the filter element and is blocked in a second position of the filter element; and

(b) the connection from the inlet to the region surrounding the first filter section is blocked in the first position of the filter element and is open in the second position of the filter element.

A filter element with two filter sections makes it possible to completely clean the water even during backwashing. In the first position, that is to say in the operating position, the water flows from the inlet into the outer annular space and from there through the second filter section inwards. In the second position, that is to say in the back-flushing position, the annular projection rests on a shoulder on the inner wall of the filter cup. The connection to the outer annular space is then interrupted in the region of the second filter segment. The water flows inwardly through the first filter section. The water then flows outwardly from the interior space of the filter into the annular space. In this case, this section of the filter element is backwashed. The division into two filter sections achieves that all water is filtered and can thus also be used at the outlet. That is, the water supply need not be interrupted for backwashing. At any time, filtered water is available for use.

Preferably, the bottom of the filter element is loaded in the direction of the first position of the filter element with the spring force of a spring. This ensures that the filter element moves back into the operating position after the end of the backwashing.

In a particularly preferred embodiment of the invention, it is provided that the closable housing opening is arranged coaxially with respect to the filter cup and with respect to the filter element on the upper side of the housing. A pressure reducing cartridge (druckmineraptron), for example, can be inserted into the opening. However, it is also possible to introduce a handling device into the filter, by means of which the handling of the filter is carried out by hand.

Preferably, a bulb or other cut-off is provided at the discharge. A sudden pressure loss can be produced in the bottom region of the filter cup by means of a ball head or a comparable stop, with which a force is produced which is sufficient to move the filter element from the operating position into the backflushing position also against the force of a spring.

In a particularly preferred embodiment, an impeller with a reduced flow diameter is arranged inside the filter element, by means of which impeller the water can be guided in the backflush position in such a way that the water flows through the filter element in the operating position counter to the (entgegen) flow direction at an increased flow speed. The higher flow rate enables better detachment of the sessile (festsitzende) dirt particles from the filter element. At the same amount of water, the impeller induces a higher flow velocity through a reduction in the flow cross section or through pulsation (sometimes called impingement).

Preferably, the pusher is rotatably supported about a guide rod. By rotating the propeller, the water jet can be directed in succession to different angular ranges of the filter element.

Preferably, the guide rod and the pusher remain immovable in the axial direction. Only the filter element with the valve closing body then moves. The guide rod forms a guide for the propeller that is fixed in the axial direction. The pusher can be secured (sometimes referred to as a stop) in its axial position, for example by a safety ring.

The filter element is preferably closed by a base and the base has a receptacle for the guide rod. The bottom can be molded onto the filter element or screwed, inserted or clipped onto the filter element from below. The receptacle can be screwed or inserted into an opening in the base or molded to the base.

In a further embodiment of the invention, it is provided that the guide rod is held axially immovably with its upper end in a receptacle in the threaded spindle. This ensures that the guide rod is securely held not only at the upper end but also at the lower end.

Preferably, the impeller has a nozzle slit which produces a long, narrow, elongate (langgestereckten) beam. The nozzle slot is elongated differently from a rotationally symmetrical nozzle and tapers only in one direction. The nozzle slot can extend from top to bottom completely or partially over the height of the filter element. In particular, the impeller can have two opposing nozzle slots. The lateral forces generated by the beam are then compensated.

In a particularly preferred embodiment of the invention, it is provided that the nozzle slots are arranged offset in the axial direction. In this way, the lateral forces are compensated for at maximum flow velocities, since only one nozzle slot is always associated with each height range.

In a particularly preferred embodiment of the invention, it is provided that the nozzle slot is directed at an acute angle to the inside of the filter element. The impeller is then hydraulically driven to rotate.

The design of the invention is the subject of other claims. Embodiments are explained in more detail below with reference to the attached figures.

Definition of

In the present description and in the claims that follow, all concepts have the meaning familiar to the person skilled in the art, which are set forth in the specialist literature, standards, in particular DIN EN 806-1 and DIN EN 1717, and in particular dictionary-type, such as www.Wikipedia.de, www.wissen.de or www.techniklexikon.net, competitors, research institutes, universities and associations, such as the german gas and water industry association of the registered association or the german engineer association, for example. In particular, the concepts used do not have the reverse meaning as would occur to one skilled in the art from the above disclosure.

In addition, the following meanings for the concepts used are based here:

a cut-off portion: are each type of mechanism that completely or partially occludes fluid flow. Typical shut-offs are bulbs or valves.

Accessories: are structural components for terminating, adjusting or influencing a material flow (Stoffstr) for installation in or at a pipeline or other fluid-handling equipment. The fitting can be constructed in one piece or in multiple pieces and is mounted at a location in or at the pipeline. Accessories such as, and not critical: coupling device, coupling accessory, main stop accessory, maintenance accessory, throttle accessory, get material position, get material accessory, evacuation accessory, insurance accessory, safety accessory and timing accessory.

A discharge unit: is an opening in the housing on the discharge side, from which opening a material flow can flow out. The opening can be connected in particular to a line or a further fitting or can be opened to the environment (frei zur atmosphh ä re hin).

Axial direction: is the direction of the axis of rotation of a completely or partially rotationally symmetrical structural component, such as, for example, a tube or an elongated housing. For structural components without rotational symmetry, this is the main flow direction in the structural component section.

A passage: is a connection which realizes a material flow.

An entry section: is an opening at the inlet side in the housing, into which inlet part a material flow can flow. The opening can in particular be coupled to a pipeline or another fitting or be open to the environment.

A filter: is a mechanism by which solid material from a fluid stream is retained.

A housing: outward restraints for materials, structural components, instruments and gauges. The housing can be designed as a single piece or as multiple pieces from a plurality of connected housing parts and made of one or more materials (materialies).

A handle: outwardly projecting structural members for manual retention or movement.

Radial: perpendicular to the axial direction.

Tube: a hollow body consisting of a cylindrical section. Typically as a pipeline.

Backwashing: through the flow element or filter material in the opposite direction and discharges the flushing medium outwards.

Backwashing the filter: a filter cleaned by backwashing.

Shoulder: transition of sections of different diameter or thickness.

Taking over: an edge or transition piece at the opening.

Drawings

Fig. 1 is a cross-section through a backflush filter assembly with a filter and an auxiliary filter for filtering the backflush water in the operating position.

Fig. 2 corresponds to the illustration in fig. 1 in the backflush position.

Fig. 3 is a cross-section through the assembly from fig. 1 along section line D-D.

Fig. 4 is a cut-away, perspective illustration of a portion of the filter assembly from fig. 2.

Fig. 5 is a side perspective illustration of a pusher for insertion into the filter assembly from fig. 1 and 2.

Fig. 6 is a perspective illustration from obliquely above of a pusher for insertion into the filter assembly from fig. 1 and 2.

Fig. 7 is a side view of the propeller from fig. 5 and 6.

Fig. 8 is a sectional illustration along a vertical sectional plane of the propeller from fig. 5 and 6.

Fig. 9 is a sectional illustration along a horizontal sectional plane of the impeller from fig. 5 and 6.

Fig. 10 illustrates the assembly with the built-in pressure reducer in the operating position from fig. 1.

Fig. 11 illustrates the assembly with backwash robot in the backwash position from fig. 1.

Fig. 12 is a general view from the perspective of the assembly of fig. 11.

Fig. 13 is a perspective illustration of the filter element.

Fig. 14 shows the assembly from fig. 1, in which the filter is separated from the coupling fitting.

Figure 15 shows a backflush filter assembly according to the prior art, in which the filter is separated from the coupling fitting.

Fig. 16 is a horizontal section along the sectional plane B-B in fig. 1.

Fig. 17 is a horizontal section along the sectional plane F-F in fig. 2.

Fig. 18 is an exploded illustration of the entire assembly shown in fig. 1.

Detailed Description

Fig. 1 and 2 illustrate a filter assembly, generally indicated at 10. The assembly 10 is used to filter potable or non-potable water. The assembly 10 has a coupling fitting 12 with a housing 20 of a known type of construction. The coupling fitting 12 has an inlet 14 and a coaxial outlet 16, by means of which the coupling fitting can be fitted in a pipeline (not shown). In the present embodiment, the inlet coupling 14 is aligned with the outlet coupling 16. However, it is also possible to use a flange, in the case of which the annular channel is arranged coaxially around the central channel. The coupling fitting 12 can be inserted directly into the line (not shown) via the coaxial inlet 14 and outlet 16. In the present exemplary embodiment, a threaded part 18 with a nut 22 is provided for this purpose.

The housing 20 has a downwardly projecting, external coupling socket 26 with an internal thread. The housing 20 forms a downwardly projecting housing opening in the region of the coupling stub 26. An adapter 28 is screwed into the internal thread of the connecting stub 26, and a filter cup 30 made of transparent plastic is screwed into the adapter 28. It is understood that the filter cup 30 can be produced from other materials as well. Coaxially with respect to the outer coupling socket 26, the housing 20 forms an inner coupling socket 32 with a tube 74 inserted into the downwardly projecting housing opening. For this purpose, a wall 31 is provided on the inlet side as far as the housing opening, which separates the housing interior from the inlet 14 above the inner connecting piece and connects it to the outlet 16. The inner coupling stub 32 has a smaller diameter than the outer coupling stub 26 and is arranged substantially coaxially.

The wall 31 is slightly offset relative to the outer connecting stub 26, so that an annular region 34 between the inner connecting stub 32 and the outer connecting stub 26 is connected to the inlet 14. The inner space 38 of the inner connecting piece 32 is connected to the outlet 16.

A substantially cylindrical filter element 44 made of plastic is guided axially movably into the filter cup 30 in the manner described below. The filter element 44 is shown in isolation in fig. 13. The filter element 44 has four vertical supports 54. The support 54 has a triangular cross-section, as can be seen well in cross-section D-D in fig. 3. Between the support elements 54, annular sections 64 are molded one on top of the other. The annular sections 64 lie closely one above the other and form a small intermediate space. The screen 124 is pulled up (aufgezogen) onto the thus formed, cylindrical filter element 44. This can be seen in fig. 3. The ring section 64 and the sieve 124 together with the support 54 trap dirt particles in the water, while the water can flow inwards through the intermediate space and the sieve 124.

The filter element 44 has two filter sections in the axial direction, with an annular section 64 and, respectively, special screen components: a first, smaller filter portion 68, which is arranged in the upper region in the illustration, and a second, larger filter portion 66, which is arranged in the lower region in the illustration. This can be seen well in fig. 1, 2 and 13. The upper first filter section 68 forms an auxiliary filter. The lower second filter section 66 forms the main filter. Between the

filter sections

66 and 68 is a region 70 without intermediate spaces. In said area 70, an annular projection 72 is molded on the outside. Above the upper filter section 68, a further annular projection 42 is provided. The annular projection 42 has an annular groove with a seal 40. The seal 40 is embodied in the present embodiment as a groove ring.

The sealing element 40 seals the annular space 46 formed between the support 54 of the filter element 44 and the inner connecting stub 32 upwards. The annular space 46 can be seen in fig. 3. That is, no water can flow outwardly past the filter element 44 and upwardly into the drain region 38. The lower, free end of the tube 74 of the inner connecting stub 32 forms a stop for the movement of the filter element 44 (if the filter element is stopped by the annular projection at the connecting stub 32).

The filter element 44 is axially movable. Fig. 1 shows the filter element 44 in an upper position. This is the operating position. Fig. 2 shows the filter element 44 in the lower position. This is the backwash position. The filter cup 30 is slightly flared upward. The lower region 48 is designed to be slender on the outside and has a smaller diameter on the inside. Thereby forming a shoulder 50 at the inner wall portion of the filter cup 30. In the backflush position, the annular projection 72 rests against an inner wall of the filter cup 30 in the region of the shoulder 50. In this way the annular space 46 is separated into an upper annular space 58 and a lower annular space 56. This can be seen in fig. 2. The water is able to flow from the lower annular space 56 to the upper annular space 58 in the backwash position. In the operating position, the annular projection 72 is arranged above the shoulder 50. The annular space 46 is continuous. This can be seen in fig. 1.

A substantially tubular extension 45 is screwed into the lower end of the filter element 44 by means of an external thread 47 at the upper end. The bottom 52 is screwed into the lower end of the extension 45. For this purpose, a thread 60 is provided. The bottom 52 encloses the structural group of filter elements 44 and extensions 45. The spring 53 presses from below onto said bottom 52. For this purpose, the base 52 forms a downwardly open, annular receptacle 55 in which the upper end of the spring 53 is received. Thereby causing a force to be exerted upwardly on the structural group of filter element 44 and extension 45. The cup bottom 84 acts as a spring support.

When the annular projection 72 stops at the shoulder 50, the downward movement of the filter element 44 is limited by the annular projection 72. In the central axis, the bottom 52 forms a projection 76 which extends downwards in the axial direction. The projection 76 is provided with a likewise axial receptacle 80 which opens upwards and in which the guide rod 78 is received. In the present exemplary embodiment, the receptacle 80 is provided at the upper end with an additional edge, by means of which the length of the receptacle is increased.

The filter cup 30 forms a downwardly projecting ring 86 below the cup bottom 84. The ring 86 is provided with an external thread 88. A nut 90 is threaded onto the external threads 88. The transition ring 89 is held in its position by the nut 90, which is inserted with two seals 91 into the hollow space formed by the ring 86. The cup bottom 84 is provided with a passageway 92. The passage 92 is aligned with the intermediate opening of the transition ring 89. The insert 93 is screwed into the transition ring 89 from below by means of an external thread 95 and is sealed by means of a seal.

A ball 97 of a ball head is arranged in the insert 93. Furthermore, the ball head comprises a steering spindle 99, which is connected to the ball 97. Fig. 1 shows a hand-operated embodiment. In the present embodiment, a handle 101 is connected to the steering main shaft 99. Figures 11 and 12 show an embodiment with a back flush full automation. Here, a motor 110 is connected to the steering main shaft 99 instead of the handle 101. The motor 110 triggers a backwash, for example after a certain period of time has elapsed, in which the motor rotates the steering spindle 99.

The steering spindle 99 can be rotated manually or automatically about an axis horizontal in fig. 1 in the plane of the drawing. The ball 97 has a passage 103. In the operating position shown in fig. 1, the passage is in a horizontal direction. Then the bulb ends. By rotation of the ball 97, the passage is aligned with the passage 92. The backwash position is shown in figure 2. The discharge connection 105 is screwed into the insert 93. For example, a hose can be plugged onto the discharge connection 105. The assembly of the molded ring 86, nut 90, insert 93 and ball head is arranged in a plastic housing 107. The drain coupling 105 extends from the plastic housing 107. The plastic housing 107 can also be produced from any desired material instead of plastic. The plastic housing forms a lateral socket 109 through which the steering spindle and the handle extend. It is understood that every other cut-off unit can be used instead of a ball head.

In the operating position, the filter element 44 is in an upper position, which is shown in fig. 1. In this position, the bulb closes off the passage 92 in the cup bottom 84.

The inner wall portion of the filter cup 30 bows outwardly above the cup bottom 84. Thereby, the annular arch 82 is formed. Above the arching 82, an annular projection 24 is moulded at the inner wall portion. The reduction of the inner diameter of the filter cup 30 is performed by the annular projection 24. An annular seal 36 is provided externally at the lower edge of the filter element 44. The annular seal 36 is held between an outer annular projection 37 and the bottom 52. In the operating position, the annular seal 36 is located at the level of the annular projection 24 when the filter element 44 is in the upper position. As a result, neither water nor dirt particles can pass by the annular seal 36 into the region directly in front of the cup bottom 84.

In the backflush position, the filter element 44 is in a lower position, which is shown in fig. 2. The seal 36 is then at the level of the arching 82. In this position, water can flow past the seal 36 via the arch 82.

The housing 20 at an upper end forms a passageway 98 outwardly. The passage 98 is arranged coaxially with respect to the filter element 44 and with respect to the guide rod 78 and is closed with a cover 96. A pressure-reducing cartridge 100 can be inserted into the passageway 98 as needed. This is shown in fig. 10. The discharge pressure can be adjusted by the decompression cylinder.

Fig. 3 is a cross-section along the sectional plane D-D in fig. 1. The guide rod 78 is arranged on the center axis. The tube 74 of the inner socket 32, which is fixed to the housing, holds the guide ring 62 by means of ribs. The upper end of the guide rod 78 is guided through the guide ring 62. The guide ring can be seen well in fig. 16. A securing ring 112 engages (greifen) in the annular groove in the guide rod 78 above and below the guide ring 62 and holds it in its axial position.

An impeller, generally indicated at 126, is disposed in the interior space of the lower filter section 66. The impeller 126 can be seen well in fig. 3 and 5 to 9. The pusher 126 has a tubular guide 128 on the inside, which extends in the axial direction around the central axis. The guide rod 78 is guided loosely through the guide portion 128. A coaxial outer collar 130 is connected to the tubular guide 128 via a radial web 132. In this embodiment, two opposing radial bridges 132 are provided. It is understood that one or more radial bridges 132 can also be provided. An annular space 134 is formed between the collar 130 and the tubular guide 128. Water flows in the annular space 134.

The collar 130 forms two opposing nozzle slots 136, offset by an angle of approximately 90 ° with respect to the radial webs 132. As can be seen in fig. 6, the nozzle slot 136 extends in the axial direction over approximately half the height of the impeller 126. In this case, one of the nozzle slots 136 is arranged in the upper region and one of the nozzle slots is arranged in the lower region. The nozzle slots 136 are directed at an acute angle toward the inside of the filter element 44 and the screen 124. That is to say, the water jet exiting from the opening of the longitudinal nozzle 136 during the backwashing has an elongated shape in the axial direction and strikes the filter element 44 and the sieve 124 obliquely. The water that is pressed through the nozzle slit 136 drives the impeller in a rotational movement about the central axis. That is, the water continuously hits different areas of the inside of the filter element. The securing rings 170 and 171 engage in associated circumferential grooves in the guide rod and secure the pusher 126 against axial movement. The pusher is held in its axial position.

The impeller 126 is designed such that the upper side of the nozzle slot 136 is closed. This can be seen in fig. 2. In contrast, the (achsnahe) region of the annular space 134 inside the impeller 126 near the axis remains open upward.

In the following, it is explained how the water flows through the fitting in the operating position shown in fig. 1. Here, the arrows illustrate the flow direction.

In the operating position shown in fig. 1, the filter element 44 is in the upper position. The ball head is closed. From the inlet 14, the water reaches the annular channel 34 in the housing 20 via the connection 106. This is illustrated by arrow 108. The annular channel 34 is connected to the inner space of the filter cup 30. This is illustrated by arrow 108. The filter element 44 is disposed in the interior space of the filter cup 30. An annular space 150 is formed between the filter cup 30 and the filter element 44. The water flows past the annular protrusion 72 in the direction of the arrow 146 into the annular space 150. The water flows from the annular space 150 into the filter element 44. Here, the water flows from the outside inwards through the filter section 66 below the filter element 44. This is illustrated by arrow 148. Dirt particles hang up on the filter element 44 on the outside in the lower filter section 66. The filtered water flows upwardly in the annular space 46 from the lower filtering section 66 and the upper filtering section 68 passing by the propeller 126 externally. This is illustrated by arrow 152. The water then flows through the interior space 38 of the housing in the direction of the arrow 154 to the drain 16. Where the water is available for additional use. Here, a pressure reducing valve 100 can be provided as required, as this is shown in fig. 10.

Over time, the filter incorporates dirt particles. Thereafter, the filter must be backwashed. The backwash position is shown in figure 2. To reach the backwash position, the handle 101 and hence the ball 97 are rotated. As described above, the bulb opens with this rotation. Thereby opening the passage 92 in the cup bottom 84 of the filter cup 30. The water flows out downwards.

The area below the seal 36 at the bottom 52 is hydraulically separated from the area above the bottom. A force is exerted downward on the bottom 52 and the filter element 44 against the spring force of the spring 53 by a sudden pressure drop below the bottom 52. The structural group of filter element 44, tubular extension 45 and base 52 is moved downwards until annular projection 72 comes to rest on shoulder 50. The backwash position thus reached is shown in fig. 2.

In the backwash position, the region 58 above the annular projection 72 is separated from the region 56 below the annular projection 72. The water is no longer able to flow into the annular space 150 surrounding the lower filter section 66. The water flows inwardly through the upper filter section 68 in the direction of the arrows 156. The water flows from top to bottom through the upper open portion of the impeller 126 into an annular space 134 inside the impeller 126. From there, the water is pressed through the lower filter portion 66 and the associated screen 124 from the inside to the outside via the nozzle slot 136. In this case, dirt particles adhering to the outside are dragged away together. The increased flow velocity caused by the impeller 126 achieves that even the immobilized particles are detached. The impeller 126 is set in rotation by the flow being obliquely centered (auftrifft). That is, the entire angular range is swept and backwashed. The division into two nozzle slots avoids lateral forces.

The seal 40 does not allow the flow of unfiltered water upwards. Accordingly, the backwash water flows downwardly through the now open passage 92. The seal 36 interacts with the annular projection 24 and the arching 82. In the operating position, the seal 36 bears against the annular projection 24. Thereby completely separating the area below the seal from the area above the seal. In the back-flushing position, the seal 36 is at the level of the arching 82. Then water can flow down past the seal. The opening of the ball causes a sudden pressure drop which causes a force which acts completely on the filter element 44. The filter element is thus moved down into the backflushing position not by hand, but hydraulically after opening. This allows for semi-automatic handling as shown in fig. 1 and 2 and fully automatic handling as shown in fig. 11 and 12. The use of the propeller 126 makes the assembly slimmer and of smaller diameter with the same filter area (Filterfl ä che). Fewer structural components are required.

The assembly is configured such that water can flow from the inlet 14 to the outlet 16 even in the backwash position. That is, the water is available regardless of whether it is just back flushed or not. The (gezapfte) water taken off at the outlet 16 is also filtered during back flushing by the auxiliary filter 68.

The current assemblies include known structural types of coupling fittings that have been used in a number of backflush filters. An example of such a coupling fitting is shown in fig. 14. By using the tube 74 and the adapter 28, it is possible to use the filter assembly described above with the same coupling fitting 12. The filter assembly to be manually actuated can thus be replaced in a particularly simple manner by a semiautomatic or fully automatic backflush filter assembly, as is illustrated in fig. 15. For this, the installation does not have to be restarted (aufgebrochen).

The embodiments explained above are intended to illustrate the invention claimed in the claims. Features disclosed in connection with other features can generally also be used individually or in combination with other features which are explicitly or implicitly disclosed in the embodiments herein or in the drawings. Dimensions and sizes are merely exemplary. Suitable ranges are derived from his expert knowledge to the expert in the field and therefore do not need to be explained in more detail here. The disclosure of a particular design of a feature does not imply that the invention should be limited to this particular design. Rather, such a feature can be realized by numerous other designs familiar to those skilled in the art. The invention can therefore be implemented not only in the form of the illustrated design, but also in all designs covered by the scope of protection of the appended claims. Thus, for example, it is possible to vary the coupling fitting and its connection to the housing in various ways without departing from the inventive concept.

The terms "upper", "lower", "right" and "left" refer only to the attached drawings. It is understood that the claimed device can assume other orientations as well. The concept of "comprising" and "including" means that additional, unrecited members can be provided. All features which fall under the notion of "substantially", "mostly" and "mainly" have, for the most part (mehrheilich), a property or content, that is to say more than all the other mentioned components or properties of the feature, that is to say more than 50% in the case of two components, for example.

Claims

1. A backflush filter for filtering drinking or non-drinking water, the backflush filter being transitionable from an operating position in which water is directed from an inlet portion through the filter to an outlet portion, to a backflush position in which water is directed from the inlet portion in an opposite direction through the filter to an outlet portion, for backflushing, the backflush filter comprising:

(a) a housing (12, 20) having an inlet portion (14) and an outlet portion (16);

(b) a filter cup (30) arranged at the housing (12, 20), the filter cup having a closable discharge;

(c) a substantially cylindrically configured filter element (44) which is guided axially movably between a first stop and a second stop and which is arranged in the filter cup (30) such that an annular space (150) which can be connected to the inlet is formed between the filter element (44) and the filter cup (30) and the filter element is closed off at the bottom;

(d) an annular projection (72) on the outside of the filter element (44), which cooperates with a shoulder on the inner wall of the filter cup in such a way that the annular projection and the shoulder cooperate with one another in such a way that the shoulder on the inner wall of the filter cup is formed in a manner that the annular projection and the shoulder on the inner wall of the filter cup are mutually offset in relation to one another

(i) A first connection from the inlet to an outer annular space (150) is open in a first position of the filter element (44) and is blocked in a second position of the filter element; and

(ii) a second connection from the access point to the interior of the filter element is blocked in the first position of the filter element (44) and is open in the second position of the filter element (44);

it is characterized in that the preparation method is characterized in that,

(e) the filter element (44) is provided with a seal (36) at the end on the bottom side,

(f) the inner wall of the filter cup (30) is profiled in such a way that

(i) A sealing element (36) at the bottom-side end of the filter element (44) rests in a sealing manner in the first position against an inner wall of the filter cup (30) and closes the annular space (150); and

(ii) in the second position, an intermediate space (82) is formed between the sealing element (36) and an inner wall section of the filter cup (30), through which the water and possibly dirt particles can pass from the outer annular space (150) to the discharge.

2. The backflushing filter according to claim 1, characterized in that the filter element (44) has a first filter section (68) and a second filter section (66) and an annular projection (72) on the outside of the filter element (44) between the first filter section (68) and the second filter section (66) for separating the outer annular space (150) from a region outside the first filter section (68), wherein the annular projection cooperates with a shoulder on an inner wall of the filter cup in such a way that the shoulder interacts with a shoulder on the inner wall of the filter cup

(a) The connection from the inlet to the outer annular space (150) is open in a first position of the filter element (44) and is blocked in a second position of the filter element; and

(b) the connection from the inlet to the region surrounding the first filter section (68) is blocked in the first position of the filter element (44) and is open in the second position of the filter element (44).

3. The backflush filter according to claim 1 or 2, characterized in that the bottom (52) of the filter element is loaded in the direction of the first position of the filter element (44) with the spring force of a spring.

4. The backflush filter according to claim 1 or 2, characterized by a closable housing opening which is arranged coaxially with respect to the filter cup (30) and with respect to the filter element (44) on the upper side of the housing (20).

5. The backflushing filter according to claim 1 or 2, characterized in that a propeller (126) having a reduced flow diameter is provided inside the filter element (44), by means of which propeller the water can be guided in the backflushing position in such a way that the water flows through the filter element (44) in the operating position counter to the flow direction at an increased flow speed.

6. The backflush filter according to claim 5, characterized in that the impeller (126) is rotatably supported about a guide rod (78).

7. The backflush filter according to claim 6, characterized in that the guide rod (78) and the impeller (126) remain immovable in the axial direction.

8. The backflush filter according to claim 7, characterized in that the bottom (52) has a receptacle (84) for the guide rod (78).

9. The backflush filter of claim 8, wherein a bulb or other shut-off is provided at the drain.

10. The backflush filter according to one of claims 6 to 9, characterized in that the guide rod (78) is held axially immovably with the upper end in a receptacle in the adapter (74).

11. The backflushing filter according to claim 5, characterized in that the impeller (126) has nozzle slots (136) which produce an elongated, elongate jet.

12. The backflush filter of claim 11, wherein the impeller (126) has two opposing nozzle slots (136).

13. The backflush filter according to claim 12, characterized in that the nozzle slots (136) are arranged offset in the axial direction.

14. The backflush filter according to any one of claims 11 to 13, characterized in that the nozzle slots (136) are directed at an acute angle towards the inside of the filter element (44).