DE20217081U1 - Distribution unit for the permeate from a reverse osmosis membrane, for the supply of purest water to a dialysis apparatus, has a secondary ring channel at the primary channel, to prevent contamination - Google Patents

Abstract

The supply system for the delivery of the purest water to a dialysis apparatus, together with a reverse osmosis unit, has at least one secondary ring channel with its upstream section (5) concentric within the primary channel (1) to distribute the permeate from the reverse osmosis membrane. The secondary ring channel has a connection section outside the primary channel, and its downstream end (8) opens into the primary channel. The upstream section of the secondary ring channel is a straight section, from the curve (4) of the primary channel between its two straight and parallel sections (3), which can contain a throttle (10).

Description

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Manfred Völker VK 02855 GM

63825 Blankenhain

Ultrapure water supply system for dialysis machines

The invention relates to an ultrapure water supply system for at least one, preferably several dialysis machines of a dialysis station, with a reverse osmosis device (RO device) that supplies ultrapure water or permeate to a permeate distribution system that has a primary line and at least one secondary ring line branching off from it, forming a bypass, to which the at least one dialysis machine is connected. The permeate flow is divided in the permeate inlet by the secondary ring line, with one part flowing further through the primary line - preferably a ring line - and the other part through the secondary ring line.

The ultrapure water supply using reverse osmosis offers great advantages, as membrane filtration filters out almost all inorganic particles, colloids and germs as well as endotoxins and salts from the raw water. A major problem with membrane filtration using reverse osmosis is that if the flow rate is too low and especially if the permeate in the permeate distribution system is at a standstill, impurities can form that lead to biofilm growth and germination in the permeate. This occurs in particular when there is no or insufficient flow through branches and dead spaces in the permeate distribution system and when the dialysis plant is down, which can be estimated at around 6,000 hours per year.

The present invention is based on the object of further developing an ultrapure water supply system of the type in question in such a way that contamination in the permeate is avoided as far as possible without significantly increasing the operating costs.

This object is achieved according to a first aspect of the present invention by the features of claim 1.

According to a second aspect of the present invention, this object is solved by the features of claim 9.

Advantageous embodiments of the invention are characterized in the dependent claims.

According to the first aspect of the present invention, the at least one secondary ring line is arranged with its upstream end section within the primary line and then exits from the primary line through the wall of the primary line, the associated dialysis machine being connected to the section of the secondary ring line running outside the primary line. The secondary ring line then flows back into the primary line with its downstream end section.

During dialysis, a permeate flow constantly flows through the primary line. Since the secondary ring line, which connects the extraction point of the dialysis machine with the primary line, is arranged with its upstream end section, i.e. the inlet area, within the primary line, the permeate flows into the secondary ring line without forming dead spaces, so that even when the permeate is intermittently extracted by the dialysis machine, there is always sufficient flow through it, so that germination of the permeate fed to the dialysis machine is safely avoided. The secondary ring line flows back into the primary line with its downstream end section.

It is preferred that the upstream end section of the secondary ring line is arranged concentrically in the primary line, i.e. in the central region in which the permeate flows fastest.

It is also advantageously proposed that the upstream end section of the secondary ring line runs in a straight line and exits from the primary line in the area of a bend in the primary line. This also keeps the flow resistance in the secondary ring line as small as possible. If the primary line runs in a straight line, the secondary ring line exits the primary line with a curved section.

In further detail, it is proposed that the secondary ring main rejoins the primary line in the area where its upstream end section is located within the primary line. The downstream end of the secondary ring main can be flush with the wall of the primary line, i.e. the secondary ring main does not protrude into the interior of the primary line.

In an alternative embodiment, the secondary ring line flows back into the primary line downstream of its exit from the primary line. Here too, the entry can be made as a flush connection to the wall of the primary line, or - which is preferred here - the secondary ring line extends with its downstream end section into the primary line. The arrangement can be such that the central longitudinal axis of the secondary ring line either coincides with the central longitudinal axis of the primary line or is aligned with it. The secondary ring line can also flow into the primary line off-center or at a right angle.

The inventive pipe-in-pipe arrangement of the inlet area of the secondary ring line in the primary line ensures that the secondary ring line - just like the primary line - is constantly flushed by a permeate flow without dead space during dialysis operation, so that no contamination can form in the lines.

According to a second aspect of the present invention, it is provided that in the primary line of the permeate distribution system a container with a

UV lamps and a circulation pump are installed. This makes it possible to expose the permeate content in the container to UV radiation and to circulate it at least temporarily during the considerable downtimes of the dialysis operation. This means that, with an appropriate design of the system and sufficient duration of exposure, the permeate can receive a radiation dose that is equivalent to disinfection. Since the circulation of the permeate takes place through a specially designed pump installed in the permeate line, a high flow rate of the permeate can be achieved with a relatively low pump output. Compared to hot cleaning, this process offers considerable cost advantages, with the additional equipment and energy expenditure being considerably lower.

After UV irradiation of the contents of the permeate distribution system, a flushing process without UV irradiation should be carried out before the next supply of permeate to the dialysis machines is started in order to eliminate the UV-treated organic substance. For this purpose, the entire ring line contents should be eliminated.

The ultrapure water areas of the reverse osmosis device are also advantageously included in this UV cleaning process.

By inserting the additional circulation pump and the container with UV radiation device into the permeate ring line, it is possible to carry out permeate circulation with UV radiation during downtimes of the reverse osmosis device and dialysis operation, which effectively prevents biofilm growth and germination in the permeate. The energy and cost expenditure associated with this is very low.

Further details of the invention emerge from the following description and from the drawings.

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Figure 1 shows a longitudinal section through part of a primary line of the permeate

Distribution system with integrated secondary ring main;

Figure 2 shows a perspective arrangement of the line part according to Figure 1,

Figure 3

up to 6 alternative arrangements of secondary ring lines and

Figure 7 is a flow diagram of the ultrapure water supply system according to the invention.

attachment.

Reference is first made to Figures 1 and 2. The part of a primary line 1 shown contains two straight, parallel pipe sections 2, 3, between which there is a semicircular section 4. The permeate flows into the section 3 on the left in the figure and flows out of the section 2 on the right in the figure.

The upstream end section 5 of a secondary ring line 6 is arranged within the inlet section 3 - concentrically to it. The straight upstream end section 5 exits through the wall of the primary line 1 in the area of the semicircular section 4. Shortly after the exit, the upstream end section 5, which was arranged vertically until then, changes into a horizontal, essentially U-shaped section 7 after a corresponding bend, with the changes in direction being rounded so that the flow resistance remains low. The essentially U-shaped section 7 of the secondary ring line 6 finally leads back into the primary line 1 at a further bend with the downstream end section 8, in that the downstream end section 8 passes through the wall of the primary line 1 in the area of the semicircular section 4. The end of the downstream end section 8 only protrudes a short distance into the interior of the primary line 1.

The arrangement is such that the central longitudinal axes of the upstream end section 5 and the downstream end section 8 of the secondary

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Primary line 6 coincides with the central longitudinal axes of the straight sections 2, 3 of the ring line 1.

The secondary ring line 6 contains a coupling 9 approximately in the middle of the essentially U-shaped section for connecting a dialysis machine which is supplied with permeate from the secondary ring line 6. The primary line 1 can be provided with a throttle 10.

In the arrangement according to Figure 3, the upstream end section 5 of the secondary ring line 6 is again arranged concentrically within the straight inlet section 3 of the primary line 1, as is also the case with the embodiment according to Figure 4. In Figure 3, the downstream end section 8 re-enters the primary line 1 in an area in which the section 5 is still located within the primary line 1. The downstream end section 8 of the secondary line 6 opens vertically into the primary line 1 and ends flush with its pipe wall. The embodiment according to Figure 4 differs from the embodiment shown in Figure 1 in that the downstream end section 8 opens into the primary line 1 in such a way that the central longitudinal axis of the downstream end section 8 is offset from the central longitudinal axis of the straight section 2 of the primary line 1.

In the embodiments shown in Figures 5 and 6, the primary line runs in a straight line. The upstream end section 5 of the secondary line 6 also runs in a straight line within the primary line 1, before the secondary ring line 6 then exits laterally from the primary line 1 in a curved section 11. The downstream end section 8 opens into the wall of the primary line 1 at a right angle to the longitudinal extension of the primary line 1 and ends flush with it. Figure 5 shows, as does Figure 6, that the upstream end section 5 and the downstream end section of the secondary ring line 6 are provided with connection points 12 for the

connecting section (not shown) which is provided with a coupling (not shown) for connecting a dialysis machine.

While in the embodiment according to Figure 5 the downstream end section 8 of the secondary ring line 6 opens into the primary line 1 in a region in which the upstream end section 5 is still located within the primary line, the downstream end section 8 in the embodiment according to Figure 6 leads back to the primary line 1 downstream of the exit point of the upstream end section 5.

The flow diagram of the ultrapure water supply system according to the invention shown in Figure 7 contains a raw water inlet 12, from which the raw water is fed to a feed tank 13. A subsequent high-pressure pump 14 feeds the water in the feed tank 13 to an RO membrane 15, from which the permeate formed by the membrane filtration passes into the permeate ring line 1. The permeate flows through a permeate check valve 16, a permeate feed valve 17 and another permeate check valve 18.

The non-filtered part of the water fed to the membrane 15, the concentrate, is either fed back to the feed tank 13 after passing through a concentrate throttle 19, or is discharged as waste water, as the flow diagram shows.

The permeate is fed through the permeate feed line 20 to the extraction points of the dialysis machines 21, with the permeate not extracted flowing into the permeate return line 22. A pressure vessel 23 with a UV burner and a circulation pump 24 are integrated into the permeate return line 22.

The pressure vessel 23 is provided with a vent valve 25 through which air entrained in the permeate return line 22 is discharged before the permeate reaches the pump 24.

During dialysis operation, the permeate is supplied by the reverse osmosis device (RO device) and fed back into the feed tank 13 via the permeate feed line 20, permeate return line 22, the UV lamp in the pressure vessel 23, the check valves 26, 27, 28 and 29. The flow rate in the permeate return line 22 depends on the consumption of the dialysis machines 21 and on the permeate output of the reverse osmosis device.

To increase the flow rate and improve the rinsing process, each rinsing process is preceded by a circulation through the permeate ring line when the RO device is not in operation. The RO device is not active during this time. Valves 30 and 17 are opened and pump 24 is switched on. To equalize the pressure, the container 23 is ventilated via valve 30. The duration of the circulation can be specified. The permeate is circulated at a guaranteed flow rate via the UV lamp in the container 23 to the connection point of the dialysis machines 21, so that the line routing is essentially free of dead space.

To improve the flushing of germs or their bridges or for initial flushing and flushing after disinfection, the following procedure is used: The circulation pump 24 stops. The RO device switches on and flushes a previously entered amount of water directly into the drain via the valve 31. The valve 31 then closes. The pump 14 is switched on for 5 seconds each time to also flush the pump connections. The flushing process ends once the target flush volume has been reached.

During flushing and supplying the dialysis machines with permeate, the fill level in the pressure vessel or tank 23 is kept at the N2 level. The vessel is under pressure.

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To equalize the pressure, the tank 23 is first depressurized during circulation by opening the valve 31 and then emptied to level N1 via the feed tank 13 by opening the valve 30 and simultaneously operating the pump 24. Emptying to level N1 is also possible via the valve 31 if the height conditions are observed. Circulation takes place when the valve 30 is open. By controlling the fill level of the tank 23 and the circulation pump 24, chemical disinfection of the ring line 1 can also be carried out without involving the RO device in such a way that disinfectant is sucked in via the pump 24 until the level N2 is reached in the tank 23.

Claims (12)

1. Ultrapure water supply system for at least one, preferably several dialysis machines of a dialysis station, with a reverse osmosis device (RO device) which supplies ultrapure water or permeate to a permeate distribution system which has a primary line and at least one secondary ring line branched off from it and forming a bypass, to which the at least one dialysis machine is connected, characterized in that
that the at least one secondary ring line ( 6 ) is arranged with its upstream end section ( 5 ) within the primary line ( 1 ),
that the secondary ring line ( 6 ) with a subsequent section ( 7 ) runs outside the primary line ( 1 ) and
that the secondary ring line ( 6 ) flows back into the primary line ( 1 ) with its downstream end section ( 8 ). 2. Ultrapure water supply system according to claim 1, characterized in that the upstream end section ( 5 ) of the secondary ring line ( 6 ) is arranged concentrically in the primary line ( 1 ). 3. Ultrapure water supply system according to claim 1 or 2, characterized in that the upstream end section ( 5 ) of the secondary ring line ( 6 ) runs in a straight line and emerges from the primary line ( 1 ) in the region of a bend ( 4 ) of the latter. 4. Ultrapure water supply system according to claim 1 or 2, characterized in that the upstream end section ( 5 ) of the secondary ring line ( 6 ) runs in a straight line and then exits the straight primary line ( 1 ) in an arc. 5. Ultrapure water supply system according to one of claims 1 to 4, characterized in that the secondary ring line ( 6 ) opens back into the primary line ( 1 ) in the region in which its upstream end section ( 5 ) is located within the primary line ( 1 ). 6. Ultrapure water supply system according to one of claims 1 to 4, characterized in that the secondary ring line ( 6 ) flows back into the primary line ( 1 ) downstream of its outlet from the latter. 7. Ultrapure water supply system according to claim 5 or 6, characterized in that the downstream end of the secondary ring line is flush with the wall of the primary line ( 1 ). 8. Ultrapure water supply system according to claim 5 or 6, characterized in that the secondary ring line ( 6 ) projects with its downstream end section ( 8 ) into the primary line ( 1 ). 9. Ultrapure water supply system for at least one, preferably several dialysis machines of a dialysis station, with a reverse osmosis device (RO device) which supplies ultrapure water or permeate to a permeate distribution system, characterized in that a container ( 22 ) with a UV lamp and a circulation pump ( 21 ) downstream thereof are inserted into the permeate line ( 18 , 20 ). 10. Ultrapure water supply system according to claim 9, characterized in that the circulation pump ( 21 ) is a high-flow pump. 11. Ultrapure water supply system according to claim 9 or 10, characterized in that the container ( 22 ) is provided with a ventilation valve. 12. Ultrapure water supply system according to one of claims 9 to 11, characterized in that the container ( 22 ) with the UV lamp and the circulation pump ( 21 ) are arranged downstream of the connection point of the at least one dialysis machine ( 19 ).