WO1997046803A1

WO1997046803A1 - Reverse-osmosis pumping system

Info

Publication number: WO1997046803A1
Application number: PCT/EP1997/002468
Authority: WO
Inventors: Rosario Umberto Occhipinti
Original assignee: Telme S.P.A.
Priority date: 1996-06-06
Filing date: 1997-05-14
Publication date: 1997-12-11
Also published as: IT240722Y1; ITMI960423V0; ITMI960423U1; AU2898197A

Abstract

A reverse-osmosis pumping system with a piston-cylinder arrangement (12) having a reciprocating working piston (35) actuatable from outside by means of a piston rod (11). The compression chamber (13) remote from the piston rod (11) is connected via an intake valve (14) to a solution inlet (15) and via a pressure valve (16) to a reverse-osmosis module (18), in which the solution is conveyed under high pressure to an osmosis diaphragm (36) which allows pure liquid to flow through and delivers it to a pure liquid outlet (19). The correspondingly concentrated, still pressurised solution conveyed via a solution discharge line (28) to a valve arrangement (20) which connects the solution discharge aperture (28) to the piston rod chamber (31) of the piston-cylinder arrangement (12) on the pressure stroke, but closes it on the intake stroke and connects the piston rod chamber (31) to a discharge line (30) instead. In order to ensure the reversal of the valve arrangement (20), the latter comprises a support (21) reciprocating in a valve cylinder (22) which bears a valve piston (24) providing a seal in the valve cylinder (22), which separates a valve discharge chamber (29) connected to a discharge line (30) for concentrated solution from a valve pressure chamber (27) connected to the solution discharge line (28), the support (21) bearing a control piston (23) at one end.

Description

Reverse osmosis pumping device

The present invention relates to a reverse osmosis pump device according to the preamble of claim 1.

Such a reverse osmosis pumping device is known from US Pat. No. 4,124,488. In this known pump device, the valve arrangement has two valve pistons, one of which opens or closes the solution outlet line of the reverse osmosis module and the other opens or closes the discharge line connected to the piston rod chamber depending on the position of the working piston. The movement of the two valve pistons is coupled via a piston rod connecting the two pistons so that the drain line is closed when the solution outlet line is open and vice versa. The reversing of the two valve pistons takes place via a control piston arranged between the two valve pistons, which is pressurized by the working piston during the pressure stroke via a branch line.

The disadvantage of this known device is that two valve pistons must be provided, which must also be precisely coordinated. Another disadvantage is that the reversal of the valve arrangement between the pressure position and the drain position, in particular the return to the drain position, does not take place with sufficient reliability.

The invention is therefore based on the object of providing a reverse osmosis pumping device of the type mentioned at the outset, in which a safe means with simple means Reversal and in particular a safe return of the valve assembly to the drain position is guaranteed. In addition, the construction effort is to be reduced and the reliability of the device is to be increased.

This object is solved by the characterizing features of claim 1.

The idea of the invention essentially consists in providing a single valve piston, by means of which it is possible to switch between the pressure position and the outflow position of the valve arrangement, the changeover being effected by the pressure generated by the working piston, and to provide means for the suction stroke of the working piston to exert a compressive force on the supporting body of the valve arrangement in the direction of the outflow position and thereby to ensure the return of the valve arrangement to the outflow position. In connection with the pressure control chamber, which is connected to the pressure chamber of the piston-cylinder arrangement and which reverses the valve arrangement into the pressure position during the pressure stroke of the working piston, an automatic reversal of the valve arrangement between the pressure position and the valve is thus cleverly and simply Drain position guaranteed.

The support body of the valve arrangement is preferably acted upon by a restoring element, in particular in the form of a compression spring, which exerts a constantly acting force on the support body in the direction of the outflow position of the valve piston. According to one embodiment of the invention, the compression spring is guided on a continuation of the support body on the side of the valve piston facing away from the control piston and clamped between an outer collar present on the continuation and the adjacent end of the valve cylinder. The pressure increases during the suction stroke of the working piston dismantled in the pressure control chamber of the valve arrangement, so that the compression spring can move the valve carrier back into the drain position. The force of the compression spring is dimensioned such that it can be overcome during the pressure stroke of the working piston by the force exerted on the control piston of the valve arrangement. This results in a simple and safe automatic reversal between the pressure position and the drain position of the valve arrangement.

According to a further embodiment of the invention, the working piston is formed in two parts, with two partial pistons which can be actuated by the piston rod and form part of the pressure chamber-side end face of the working piston and which are displaceably guided in the actuating direction between two end positions and sealed against one another. The first partial piston is preferably designed as part of the piston rod, which is arranged with its one end in a central recess of the second partial piston, the first partial piston formed by the piston rod and the central recess of the second partial piston being designed so as to be reciprocally stepped in such a way that together they form the stops for the relative end positions of the two pistons to each other. This configuration has the advantage that when the piston rod is actuated in the pressure stroke direction, only one piston with a small cross-sectional area and only then the entire piston must be moved. The initial force to be exerted is therefore less. This configuration is therefore particularly suitable for manual operation. However, it can also be used in conjunction with a mechanical drive for the working piston.

Another advantage is that the movement of the small piston, for which only a smaller force has to be applied, is already used to reverse the valve actuation. Order leads. For this purpose, the smaller piston is dimensioned such that the change in volume of the pressure chamber when it is displaced relative to the larger partial piston essentially corresponds to the volume of the pressure control chamber of the valve arrangement. After reversing the valve arrangement by applying a small force, the pressure chamber communicates with the piston rod chamber of the working piston and supports the further pressure stroke.

According to a further embodiment of the invention, the outer collar of the valve carrier can also be sealingly guided in the valve cylinder and form a second control piston, which on the one hand, together with the valve piston, delimits the valve outflow space and on the other hand, with the adjacent end of the valve cylinder, delimits a second pressure control space, which is connected via a pressure control line communicates with the piston rod chamber. This second pressure control chamber, which is connected to the piston rod chamber, supports the return of the valve carrier caused by the compression spring during the suction stroke to the drain position, in that the valve carrier is acted upon by the pressure prevailing in the piston rod chamber in the direction of its drain position.

In order to bring about a rapid reversal between the pressure position and the drain position of the valve arrangement, an outlet line connected to the inlet and outlet-side end of the pressure chamber of the piston-cylinder arrangement can also be provided according to one embodiment, in which a discharge line depending on the position of the Working piston opening and closing shut-off valve is provided. The shut-off valve opens at the end of the pressure stroke and thus leads to a sudden drop in pressure in the pressure chamber, which facilitates and accelerates the return of the valve arrangement to the drain position. A particularly skillful control of the shut-off valve is specified in claim 11.

Embodiments of the invention are shown in the drawing and are described below. It shows, each in a schematic representation

1 shows a first embodiment of the invention at the beginning of the pressure stroke,

2 shows the exemplary embodiment of FIG. 1 at the beginning of the suction stroke,

3 shows a second embodiment at the beginning of the pressure stroke,

4 the embodiment of FIG. 3 at the beginning of the suction stroke,

5 shows a third embodiment at the beginning of the pressure stroke,

6 shows the embodiment of FIG. 5 at the beginning of the suction stroke,

7 shows a fourth embodiment at the beginning of the pressure stroke,

8 the embodiment of FIG. 7 at the beginning of the suction stroke,

Fig. 9 shows a fifth embodiment at the beginning of the pressure stroke, and Fig. 10 shows the embodiment of Fig. 9 at the beginning of the suction stroke.

According to FIG. 1, a working piston 35 is axially displaceably arranged in the cylinder housing 43 of a piston-cylinder arrangement 12 and has a piston rod 11 projecting outwards through a sealed bore 45 of the cylinder housing 43, which optionally with the interposition of a lever transmission, not shown, of Manual, but possibly also by a motor arrangement in the pressure stroke direction D (Fig. 1) and in the drain direction A (Fig. 2).

A suction valve 14 connected to a solution inlet 15 and a pressure valve 16 connected to an inflow line 17 are arranged on the bottom 46 of the cylinder housing 43 facing away from the piston rod 11. When the working piston 35 moves in the discharge direction A (FIG. 2), the suction valve 14 opens and sucks a solution through the solution inlet 15, e.g. Salt water, which is then directed upon subsequent actuation of the working piston 35 in the pressure build-up direction D (FIG. 1) through the then opening pressure valve 16 via the inflow line 17 to a reverse osmosis module 18 in which there is an only schematically indicated osmosis membrane 36. Due to the high pressure generated by the working piston 35 in the pressure chamber 13, pure liquid is forced through the osmosis membrane 36 and emerges from a clean liquid outlet 19 of the reverse osmosis module 18.

The correspondingly concentrated solution enters from the reverse osmosis module 18 into a solution outlet line 28, which opens at a valve pressure chamber 27 of a valve arrangement 20, which consists of a valve cylinder 22 and one therein arranged support body 21, on which at one end a control piston 23 and in the middle a valve piston 24 are arranged so that they are axially displaceable radially sealing within the valve cylinder 22. On the side of the valve piston 24 facing away from the control piston 23, the support body 21 has a continuation 51 with an outer collar 25 which serves as an abutment for a compression spring 37 which is guided on the continuation 51 of the support body 21 and on the other hand on the adjacent one End of the Ventil¬ cylinder 22 is supported. The compression spring 37 is biased towards the spring abutment 25.

The pressure chamber 13 of the piston-cylinder arrangement 12 is connected via a line 26 to the pressure control chamber 47 adjoining the control piston 23. The valve pressure chamber 27 extends between the control piston 23 and the valve piston 24 and is in flow connection with the solution outlet line 28 in every axial position of the support body 21.

On the side of the valve piston 24 facing away from the control piston 23 there is a valve drain chamber 29 in the valve cylinder 22, which is in flow connection with a drain line 30 in each axial position of the support body 21.

Between the piston rod chamber 31 of the piston-cylinder arrangement 12, which is located on the side of the working piston 35 facing away from the pressure chamber 13 in the cylinder housing 43, and the valve cylinder 22, a line 32 extends which opens in the region of the valve piston 24 in such a way that it is connected to the valve pressure chamber 27 in the position of the carrier body 21 shown in FIG. 1 and to the valve drain chamber 29 in the other extreme position of the carrier body 21 shown in FIG. 2. As can be seen in FIG. 1, the working piston 35 is designed in two parts. For this purpose, the piston rod 11 is guided through a central recess 56 of the working piston 35 and forms with its end on the pressure chamber side a first partial piston 54 which is surrounded by a second partial piston 55. At its end on the pressure chamber side, the piston rod 11 has a first outer collar 59 and a second outer collar 60, offset from the other end of the piston rod 11, the outer circumference of which is adapted to a corresponding expansion of the central recess 56 of the second partial piston 55 is. Likewise, the area of the piston rod 11 located between the two outer collars 59 and 60 is adapted to the corresponding area of the recess 56. In this area, an annular seal 61 is provided between the piston rod 11 and the second partial piston 55.

The distance between the two outer collars 59 and 60 and the length of the two extensions of the central recess 56 in the second partial piston 55 are dimensioned such that the first outer collar 59 of the piston rod 11 in one end position is flush with the end 53 of the working piston 35 on the pressure chamber side, and that the volume increase of the pressure chamber 13 by moving the first partial piston 54 into its other end position corresponds approximately to the volume of the pressure control chamber 47 of the valve arrangement 20. The stepped recess 56, together with the two outer collars 59 and 60 of the piston rod 11, thus forms the two end stops 57 and 58 for the relative movement of the piston rod 11 to the working piston 35.

The operation of the reverse osmosis pump device described is as follows:

If the piston rod 11 is actuated from the position at the end of a pressure stroke in the outflow direction A, it shifts first the first partial piston 54 relative to the second partial piston 55 and releases a volume in the pressure chamber 13 which corresponds to the volume of the pressure control chamber 47. Supported by the compression spring 37, the valve carrier 21 is thereby moved into its drain position shown in FIG. 2, in which the piston rod space 31 is connected to the drain line 30 via the line 32 and the valve drain space 29. If the piston rod 11 is actuated further in the drainage direction A, the suction valve 14 opens and the solution to be treated, for example sea water, is sucked into the pressure chamber 13 through the liquid inlet 15. The concentrated solution located in the piston rod space 31 is at the same time discharged to the outside largely without force.

As soon as the working piston 35 has reached the end position shown in FIG. 1, a compressive force D is exerted on the piston rod 11 and the working piston 35 is moved to the left in FIG. 1, again with a first relative movement of the first partial piston 54 to the second Partial piston 55 takes place, by means of which the suction valve 14 is closed and the valve carrier 21 is moved into the right end position shown in FIG. 1 against the force of the compression spring 37, in which the valve pressure chamber 27 is connected to the piston rod chamber 31 via the line 32. Now, with further movement of the working piston 35, the pressure valve 16 is opened, and the solution now located in the pressure chamber 13 is directed through the inflow line 17 into the reverse osmosis module 18, where some of the pure liquid flows through the osmosis membrane 36 to the Pure liquid outlet 19 reaches while concentrated solution is pressed into the solution outlet line 28 and via the valve pressure chamber 27 and the line 32 into the piston rod chamber 31. This creates a pressure in the piston rod space 31 that supports the movement of the working piston 35 in the direction D. The build-up of the pressure required for the entry of the reverse osmosis results from the fact that the volume released on the piston rod side of the working piston 35 is smaller than the volume of solution displaced in the pressure chamber 13. In the pressure build-up phase, the osmosis membrane 36 acts as a compensation and pressure-maintaining element due to its elasticity. As soon as the osmosis pressure is reached, an amount of pure solution corresponding to the volume difference between the piston rod space 31 and the pressure space 13 passes through the osmosis membrane 36, so that the final pressure is limited by itself.

In the exemplary embodiment according to FIGS. 3 to 10, the same reference numbers denote corresponding components as in the exemplary embodiment described above.

The embodiment of FIGS. 3 and 4 corresponds to the first embodiment with the difference that in this second embodiment a shut-off valve 38 is provided in each case in the region of the piston rod bore 45, which is defined by a discharge space 52 and a transverse channel 41 in between two seals 48 and 49 the piston rod 11 is formed, which is connected to an essentially axial drain channel 40 in the piston rod 11. The outlet channel 40 of the piston rod 11 is connected to an outlet 39 via a further transverse channel 42 of the piston rod 11.

The outlet space 52 between the two seals 48 and 49, on the other hand, is in flow connection via an outlet line 44 to the front end of the pressure space 13 of the piston-cylinder arrangement 12.

In the pressure stroke end position of the working piston 35 shown in FIG. 4, the valve 38 is opened in that the transverse channel 41 connects to the outlet space 52 between the seals 48, 49 connected and the cross channel 42 is connected to an outlet 39 under atmospheric pressure. In this way, the high pressure present in the pressure chamber 13 can be quickly reduced.

When the working piston 35 is in the other extreme position (FIG. 3), the circumferential surface of the piston rod 11 closes the valve 38, so that the pressure built up in the discharge line 44 and the discharge space 52 between the seals 48, 49 is maintained during the pressure stroke. The connecting channel 40 and the transverse channels 41, 42 are located in this position outside the cylinder housing 43.

3 and 4, this second variant is shown with only one-piece piston. Basically, a two-part piston is also considered here.

The function of the embodiment according to FIGS. 3 and 4 is as follows:

4, the valve 38 opens at the end of a pressure stroke, so that the pressure in the pressure chamber 13 is reduced via the outlet 39. As a result, the pressure control chamber 47 is depressurized, and the compression spring 37 can now switch the support body 21 with the control piston 23 and the valve piston 24 via the outer collar 25 from the pressure position shown in FIG. 3 to the drain position shown in FIG. 4. After this has been done, the working piston 35 is moved in the direction of arrow A in FIG. 4, solution, for example sea water, being sucked into the pressure chamber 13 via the suction valve 14, via the liquid inlet 15. The valve 38 closes and the concentrated solution located in the piston rod chamber 31 is pressed into the drain line 30 via the line 32 and the valve drain chamber 29. Finally, the piston 35 reaches the right one, which is shown in FIG. 3 End position.

If the direction of action of the piston rod 11 is subsequently reversed, i.e. If the piston rod 11 is now acted on in the direction of arrow D in FIG. 3, pressure is generated in the pressure chamber 13 and pressure is built up in the pressure control chamber 47 via the line 26, as a result of which the support body 21 compresses the compression spring 37 back into that of FIG. 3 apparent print position is reversed. Solution can now be pressed from the pressure space 13 into the reverse osmosis module 18 via the inflow line 17.

The pressure in the reverse osmosis module 18 is passed through the solution outlet line 28, the valve pressure chamber 27, the line 32 and the piston rod chamber 31 to the rear of the working piston 35, which in a desired manner supports the movement of the working piston 35 in addition to the application force D he follows.

The exemplary embodiments shown in FIGS. 5 to 8 differ from the first two exemplary embodiments in that the spring abutment 25 is designed as a second control piston 25 ', which, with the adjacent end of the valve cylinder 22, delimits a second pressure control chamber 33, which via a Pressure control line 34 is connected to the piston rod chamber 31. In the embodiment shown in FIGS. 9 and 10, only the compression spring 37 in the second pressure control chamber 33 is omitted compared to the variant in FIGS. 7 and 8. In principle, this is also possible in the variant of FIGS. 5 and 6.

The operation of these variants of the reverse osmosis pump device is as follows: If the working piston 35 is actuated from the position at the end of a pressure stroke in the discharge direction A, the suction valve 14 opens as shown in FIGS. 6, 8 and 10, and the solution to be treated, for example sea water, passes through the liquid inlet 15 into the pressure chamber 13 sucked in. Since pressure is generated in the piston rod chamber 31, a pressure is built up in the pressure control chamber 33 via the pressure control line 34, which, together with the compression spring 37, the support body 21 with the control pistons 23 and 25 and the valve piston 24 arranged thereon in FIG. 8 and 10 illustrated drain position, in which the piston rod space 31 is connected to the drain line 30 via the line 32 and the valve drain space 29. The concentrated solution located in the piston rod space 31 is then discharged to the outside largely without force.

As soon as the working piston 35 has reached the end position shown in FIGS. 5, 7 and 9, a pressure force D is exerted on the piston rod 11 and the working piston 35 is moved to the left in FIGS. 5, 7 and 9, whereby the suction valve 14 closes and pressure is built up via the pressure control line 26 in the first pressure control chamber 47, which, owing to the simultaneous pressure drop in the piston rod chamber 31, the support body 21 with the control pistons 23 and 25 and the valve piston 24, possibly against the force of the compression spring 37, into the pressure from FIG 5 shown pressure position, in which the valve pressure chamber 27 is connected via the line 32 to the piston rod chamber 31. Now, with further movement of the working piston 35, the pressure valve 16 can open and the solution now located in the pressure chamber 13 is now directed through the inflow line 17 into the reverse osmosis module 18, where part of the pure liquid reaches the clean liquid outlet 19 through the osmosis membrane 36 while concentrated solution in the solution outlet line 28 and via the valve pressure chamber 27 and the line 32 is pressed into the piston rod chamber 31. This creates a pressure in the piston rod space 31 that supports the movement of the working piston 35 in the direction D.

In all design variants, the valve arrangement 20 is reversed automatically and safely when the piston rod 11 is actuated accordingly.

The possibility of arranging the device according to the invention in a casing which is designed as a floating body is not shown. Such a configuration is particularly advantageous for devices for sea water desalination, which serves as an emergency device for people in distress.

Finally, it should also be pointed out that the working piston 35 can also be replaced by a pressure membrane which can be acted upon in both directions by a piston rod 11 similar to the working piston 35.

Claims

claims

Reverse osmosis pump device with a piston-cylinder arrangement (12) which can be actuated from the outside by means of a piston rod (11) and has a working piston (35) which can be pushed back and forth, the pressure chamber (13) of which faces away from the piston rod (11) via a suction valve ( 14) is connected to a solution inlet (15) and via a pressure valve (16) to a reverse osmosis module (18), in which the solution is passed under high pressure along an osmosis membrane (36), the pure liquid passes through and to a pure liquid outlet (19) and correspondingly concentrated, still pressurized solution via a solution outlet line (28) leads to a valve arrangement (20) which leads the solution outlet line (28) during the pressure stroke of the working piston (35) with the piston rod chamber (31) Piston-cylinder arrangement (12) connects, but closes during the suction stroke and instead connects the piston rod space (31) to a drain line (30), thereby characterized in that the valve arrangement (20) comprises a supporting body (21) which can be pushed back and forth in a valve cylinder (22) and which carries a valve piston (24) sealingly guided in the valve cylinder (22), said piston being connected to a drain line (30 ) for the concentrated solution connected valve drain chamber (29) from a valve pressure chamber (27) connected to the solution outlet line (28) that the support body (21) carries at one end a control piston (23) which is in the valve cylinder (22 ) is also sealingly guided and with the adjacent end of the valve cylinder (22) a pressure control chamber (47), which via a pressure control line (26) with the pressure chamber (13) of the piston-cylinder arrangement (12) is connected, and with the valve piston (24) limits the valve pressure chamber (27) that of the piston rod chamber

(31) a line (32) leads to the valve cylinder (22) and opens there in such a way that, depending on the position of the valve piston (24), it communicates either with the pressure chamber (27) or with the discharge chamber (29), and that means

(33, 34; 37) are provided which, during the suction stroke of the working piston (35), exert a force on the supporting body (21) of the valve arrangement (20) in the direction of the outflow position of the valve piston (24).

2. Reverse osmosis device according to claim 1, characterized in that the supporting body (21) is acted upon by a restoring element (37) which exerts a constantly acting force on the supporting body (21) in the direction of the drainage position of the valve piston (24).

3. Reverse osmosis device according to claim 2, characterized in that a compression spring (37) is provided as the restoring element.

4. Reverse osmosis device according to claim 3, characterized in that the support body (21) on the control piston (23) facing away from the valve piston (24) has a continuation (51) on which the compression spring (37) is guided, and on which an outer collar (25) is formed, on which the compression spring (37), which on the other hand is supported on the adjacent end of the valve cylinder (22), engages.

5. Reverse osmosis device according to one of the preceding claims, characterized in that the working piston (35) is constructed in two parts, with two partial pistons (54, 55) which can be actuated by the piston rod (11) and form part of the end face (53) of the working piston (35) on the pressure chamber side and which are in the actuating direction between two End positions are guided so as to be displaceable relative to one another and are sealed off from one another.

6. Reverse osmosis device according to claim 5, characterized in that the first partial piston (54) is arranged in a central recess (56) of the second partial piston (55), the first partial piston (54) and the central recess (56) of the second partial piston (55) are designed so as to be reciprocal to one another such that together they form the stops (57, 58) for the relative end positions of the two partial pistons (54, 55) to one another.

7. Reverse osmosis device according to claim 6, characterized in that the first partial piston (54) is designed as part of the piston rod (11).

8. Reverse osmosis device according to one of claims 5 to 7, characterized in that the change in volume of the pressure chamber (13) with rela¬ tive displacement of the first piston (54) to the second piston (55) substantially corresponds to the volume of the pressure control chamber (47).

9. reverse osmosis device according to one of claims 4 to 8, characterized in that the outer collar (25) is also sealingly guided in the valve cylinder (22) and forms a second control piston (25 ') which, on the one hand, together with the valve piston (24), the valve discharge chamber (29) and, on the other hand, with the adjacent end the valve cylinder (22) delimits a second pressure control chamber (33) which is connected to the piston rod chamber (31) via a pressure control line (34).

10. Reverse osmosis device according to one of the preceding claims, characterized in that an outlet line (44) is connected to the inlet and outlet-side end of the pressure chamber (13) of the piston-cylinder arrangement (12), in which a depending on the position of the working piston (35) opening and closing shut-off valve (38) is provided, the shut-off valve (38) opening at the end of the pressure stroke of the working piston (35).

11. Reverse osmosis device according to claim 10, characterized in that in the piston rod-side end of the cylinder housing (43) a plug (50) is inserted, in which a drain chamber (31) sealed against the piston rod (11) and the piston rod chamber (31) 52) into which the drain line (44) opens, and that the piston rod (11) has an essentially axially extending drain channel (40) which can be connected to a drain (39) and which is in the end of the pressure stroke position of the work ¬ piston (35) via a transverse channel (41) to the drain chamber (52) is connected.

12. Reverse osmosis device according to one of the preceding claims, characterized in that the device is used for the desalination of sea water.

13. Reverse osmosis device according to one of the preceding claims, characterized in that a device-receiving sleeve is provided, which is designed as a floating body.