WO2007141339A1

WO2007141339A1 - Process and apparatus for the enrichment of a liquid stream with a gas

Info

Publication number: WO2007141339A1
Application number: PCT/EP2007/055673
Authority: WO
Inventors: Uwe Sonnenrein; Carsten Brockmann
Original assignee: Balda Solutions Deutschland Gmbh
Priority date: 2006-06-09
Filing date: 2007-06-08
Publication date: 2007-12-13
Also published as: EP1926548B1; ATE457825T1; DE502007002849D1; EP1926548A1; LU91249B1

Abstract

The invention relates to an apparatus for the enrichment of a liquid stream with a gas. It comprises a flow mixer (28) having a connection for the liquid stream (12), a connection for the gas (14) and a withdrawal connection for the enriched liquid stream (16). It further comprises a differential pressure regulator (50) for regulating the gas pressure as a function of liquid pressure, such that the pressure difference between the liquid stream and the gas fed in is substantially constant. The apparatus achieves constant gas enrichment of the liquid and enables a nice head to be achieved.

Description

METHOD AND DEVICE FOR ENRICHING A LIQUID FLOW WITH ONE GAS

Technical area

The present invention relates generally to a method and apparatus for the enrichment of a liquid stream with a gas. It relates in particular to a method and apparatus for the enrichment of a drinking water stream with carbon dioxide. When in connection with the present invention of a carbonation of a liquid is mentioned, so it is generally meant the enrichment of the liquid with a gas. The enrichment of a liquid, in particular water, with gaseous carbon dioxide is to be regarded as a comprehensive special case of the generally understood formulation.

State of the art

Devices for the enrichment of drinking water with carbon dioxide (also referred to as carbonation of drinking water) have long been known. In most of these devices, the carbonation of the drinking water takes place in a reservoir, usually referred to as Karbonatorkessel. Carbonator boilers are equipped with sensors that are regularly serviced and replaced. Furthermore, there are usually several solenoid valves available. The maintenance costs during the service life are often higher than the initial costs. In addition, there are often hygiene problems due to the number of components in the water supply and the reservoir itself due to the low flow.

Recently, however, devices have also been developed to enrich tap water in a continuous process with carbon dioxide in private households or restaurants. In this continuous process, the carbonization takes place in a continuous mixer, which is connected directly to the drinking water pipe. Compared to conventional devices with reservoir, the continuous carbonation without reservoir has the advantage of being much more compact, less expensive and also more hygienic. A disadvantage of Durchlaufkarbonisierung, however, is that it is very expensive to achieve a perfect and uniform carbonization in pressure fluctuations in the drinking water pipe. As a rule, venturi and water jet nozzles have hitherto been used as mixing systems. Here, the transition of the gas into the water takes place only after mixing in the tapping line. The required long dispensing lines cause hygiene problems and are usually subject to extensive cleaning and maintenance.

An apparatus for the enrichment of drinking water with carbon dioxide in the continuous process is e.g. in WO 2004/024306. In this document proposes to keep constant the pressure in the continuous mixer by means of a spill valve in the dispensing line and an additional pressure stabilizer in the continuous mixer itself. In the gas supply line, a flow rate valve is further arranged, which is to keep constant the amount of gas fed into the continuous mixer per unit time. Furthermore, the control includes a solenoid valve in the water connection and solenoid valve in the gas connection of the continuous mixer. Both solenoids are closed if a pressure switch in the bleed line detects a pressure increase beyond the working pressure. This is a relatively complex control technology whose coordination is also relatively complicated.

PCT / DE01 / 04128 is generally concerned with a feed component for a tubular continuous mixer with sieve inserts. As far as understandable, this document also seems to suggest to regulate the feed pressure of the gas in the continuous mixer depending on the water pressure. For this purpose, a relatively complicated pressure regulating valve for the gas is presented. In practice, however, has shown that such a regulation of the feed pressure of the gas as a function of the water pressure, with strong water pressure fluctuations or small tap quantities but still does not ensure satisfactory carbonization.

Object of the invention

Object of the present invention is to provide a method for enriching a To provide liquid flow with a gas which avoids the aforementioned problems. Another object of the invention is to provide a device for enriching a liquid flow with a gas, which avoids the aforementioned problems.

These objects are achieved by a method according to claim 1 and by a device according to claim 9. Advantageous embodiments are described in the subclaims.

General description of the invention

In the method according to the invention, the liquid stream is passed through a continuous mixer, the gas is fed into this continuous mixer, so that it mixes with the liquid stream, wherein the feed pressure of the gas is controlled so that the pressure difference between the liquid stream and the gas fed in is substantially constant ,

According to an important aspect of the present invention, the flow rate of the liquid flow is kept constant by a flow rate regulator largely independent of fluctuations in the fluid pressure.

A device according to the invention for implementing this method comprises: a continuous mixer, with

a) a connection for the liquid flow, b) a connection for the gas and c) an extraction connection for the enriched liquid flow;

and a gas pressure regulator for regulating the gas pressure as a function of the liquid pressure (eg in the domestic water network or in pressure fluctuations caused by a booster pump (carbonator pump)) such that the pressure difference between the liquid flow and the injected gas is substantially constant. According to an important aspect of the present invention, this device further comprises a downstream flow rate regulator (ie downstream of the continuous mixer) for keeping constant the flow rate of the liquid flow per unit time largely independent of pressure fluctuations in its inlet, ie both in the feed line of the liquid to be enriched with a gas , as well as the output side of the continuous mixer.

By combining a:

a) keeping constant the pressure difference between the liquid stream (primarily drinking water) and the fed gas (mainly carbon dioxide) via a regulation of the gas feed pressure, and b) keeping constant the flow rate of the liquid stream by means of a flow regulator downstream of the continuous mixer,

can be achieved without great control effort a very uniform and independent of pressure fluctuations Gasanreichung, the arrangement is largely maintenance-free and hygienic due to their flow rate and water flow. In particular, results for the gas enriched liquid a very uniform Zapfbild.

Even with strong pressure fluctuations in the liquid flow, especially during short tapping operations, the gas enrichment works optimally without any readjustment. The device is particularly suitable for household use. Especially because of its unproblematic operating and maintenance characteristics.

The result of the gas enrichment can in this case via the differential pressure between the liquid flow and the injected gas and / or the flow rate of the liquid flow and / or the properties of the continuous mixer, in particular the variation of the gap width in a flow mixer described below with nozzle chamber (eg according to the teaching of WO 2004/024306 Al) are influenced or firmly regulated. In a preferred development, the invention thus relates to a method for enriching a liquid with a gas, wherein the degree of enrichment is variable. A preferred flow rate regulator comprises a throttle body arranged in a flow area of the flow rate regulator such that it reduces the flow area if the pressure in the liquid flowing therethrough increases and increases as the pressure in the liquid flowing through it decreases. Such a flow regulator does not need separate sensors and power supply. It can easily be installed in a tap pipe or a tap. A fixed or adjustable flow regulator can be used. With an adjustable flow regulator, it is also possible to influence the gas enrichment result by adjusting the flow rate.

It has already been mentioned above that the result of the gas enrichment, ie the degree of carbonation, also via an adjustability of the differential pressure between the liquid flow and the injected gas and / or the properties of the continuous mixer, in particular the variation of the gap width in a flow mixer with nozzle chamber described below (For example, according to the teaching of WO 2004/024 306 Al) can be influenced. This is particularly advantageous over prior known prior art carbonators in which variation of the degree of carbonation is achieved by simply mixing non-carbonated water with carbonated water in a variable mixing ratio. This is usually done by using a controller with solenoid valves, depending on the setting of the carbon dioxide different amounts of still water from a parallel line to the carbonated water in the outlet can get. This is preferably done via a controller with timing. The number of cycles determines the carbon dioxide content in the drink. It is therefore necessary for carbonators of this type, a high technical complexity, which is associated with a high maintenance. The complex construction and the required maintenance inevitably brings with it cost disadvantages. On the other hand, there are hygienic disadvantages, since there is a risk that the network of non-carbonated water (still water) is exposed to high risk of contamination via the tap. The carbonator according to the present invention, however, does not have such an additional supply line for still water, so that the disadvantage of increased technical complexity is basically avoided. Furthermore, practically all the water that is in disuse of the carbonator according to the invention in the lines, carbonized and thus has a significantly reduced tendency to nucleation.

In a particularly simple and reliable embodiment of the throttle body of the flow regulator is an elastically deformable body which is deformable by the pressure acting on it.

In a particularly proven embodiment of the throttle body is an O-ring which is arranged in the passage to a central control body with longitudinal grooves such that it is deformable by the pressure difference between the water inlet side and water outlet side and pressed into the longitudinal grooves of the control body.

With increasing flow pressure (ie increasing flow rate), the O-ring thus reduces the flow cross section of the longitudinal grooves of the control body. With decreasing flow pressure (ie decreasing flow rate), the O-ring resumes its original shape, whereby the flow cross-section of the longitudinal grooves of the control body increases again. In particular, such an adjustable flow rate regulator - as well as a differently constructed variable or fixed flow rate regulator - can be advantageously produced cost-effectively in plastic injection molding technology. With an adjustable flow regulator downstream of the flow mixer, with relatively little change in the amount of liters flowing through, a very different carbonating performance can be achieved, ranging from still water through "medium" (medium carbonation) to "classic" (strong carbonation) and infinitely individually adjustable.

A preferred embodiment of the continuous mixer comprises a nozzle body and an adjoining mixing chamber. The nozzle body has a nozzle ring gap and a gas injection nozzle arranged centrally with respect to the nozzle ring gap, wherein the connection for the liquid flow with the nozzle ring gap and the connection for the gas is connected to the gas injection nozzle. With such a continuous mixer, to the structure of which more details can be found in WO 2004/024306 A1, very good carbonization results can be achieved with relatively low pressure loss.

The width of the nozzle ring gap is advantageously selectable or adjustable, so that one can influence the pressure of the liquid flow in the mixing chamber and thus the degree of carbonation by choosing or adjusting the nozzle ring gap.

In an alternative embodiment of the continuous mixer this has a constant nozzle ring gap. The degree of carbonation may then be e.g. via a variable flow rate regulator - as mentioned above - be varied. A continuous mixer with a constant nozzle ring gap can be advantageously produced in plastic injection molding technology and thus allows the realization of relevant cost advantages.

In combination with a variable flow rate regulator, which can also be produced in plastic injection molding technology, infinitely adjustable carbonization results can be achieved at the lowest cost price.

Finally, the differential pressure valve disposed in the inlet of the continuous mixer, i. the gas pressure regulator for regulating the gas pressure as a function of the liquid pressure, be created in plastic injection molding technology, which leads to a further reduction of production costs.

Finally, it should be noted that due to the not too high pressures, which in carrying out the method according to the invention, e.g. occur in a device according to the invention, even the liquid or gas-carrying lines can be made completely or partially of plastic, especially in plastic injection molding technology can be created.

Be as many of the components as possible:

a) differential pressure valve b) Continuous mixer c) (fixed or variable) flow regulator (downstream of the continuous mixer) or (fixed or variable) restrictor d) Liquid or gas pipes e) Connectors

implemented in plastic, so on the one hand, a very high integration of multiple components in a component is possible, on the other hand, connection problems at connection points between individual components and lines can be minimized. By way of example, an integration of differential pressure valve and continuous mixer in one component may be mentioned here, alternatively also of continuous mixer and flow rate regulator or variable throttle, in particular including the required connecting lines.

Furthermore, it is also possible to run the continuous mixer and the flow regulator or the throttle as a fixed - ie non-adjustable - parts, and to design the differential pressure regulator variable. In this embodiment, a user can adjust the degree of carbonation by varying the differential pressure between the liquid and the gas fed in.

Finally, any combination of fixed / variable differential pressure regulators, continuous mixers, chokes, and / or flow rate controllers may also be used.

Particular advantages of the method according to the invention and of the device are obtained when the pressure difference between the fed-in gas and the liquid is set to approximately zero. In this way, the formation of gas bubbles in the flow mixer downstream lines / components can be reliably prevented, whereby a very homogeneous Zapfbild is guaranteed. This is possible, for example, with the continuous mixer with fixed nozzle chamber and annular gap described in the following exemplary embodiment. Furthermore, an operation with a substantially vanishing differential pressure with a continuous mixer according to WO 2005/105 279 Al, whose teaching as well as the teaching of WO 2004/024 306 Al by this reference is completely added to the teaching of this application. It should be noted, however, that an operation of the device and an embodiment of the method are possible even at a non-zero pressure difference. The gas pressure can generally be both above and below the pressure of the liquid, depending on the continuous mixer used. In particular, the use of a continuous mixer according to the teaching of WO 2004/024 306 Al allows the setting of a gas pressure which is also below the pressure of the liquid. In this case, a particularly efficient gas enrichment with the smallest bubble formation can be achieved.

A device according to the invention is particularly suitable for the carbonation of drinking water. In this case, the connection for the liquid flow is then normally connected to a drinking water line or to a storage tank and a downstream booster pump. The connection for the gas is connected via the differential pressure regulator with a carbon dioxide bottle and the dispensing connection via the flow regulator with a nozzle.

Brief description of the figures

Further details and advantages of the invention can be found in the following detailed description of possible embodiments of the invention with reference to the accompanying Figure 1, which shows a simplified circuit diagram of a device according to the invention for the enrichment of a liquid flow with a gas.

Description of one or more embodiments of the invention

The apparatus 10 shown in FIG. 1 has been developed in particular for the carbonation of drinking water in a continuous process at the end consumer or in restaurants. It comprises a water-side connection 12, a gas-side connection 14 and a dispensing connection 16. The water-side connection 12 is connected to a drinking water line 18 via a drinking water filter 12, a backflow preventer 14 and a shut-off valve 16. The gas-side connection 14 is connected via a shut-off valve 20 to a carbon dioxide container 22. closed, wherein the reference numeral 24 denotes a gas-side safety valve. The dispensing connection 16 is equipped with a tap 26.

The actual carbonization, i. Enrichment of the drinking water with carbon dioxide is preferably carried out in a tubular continuous mixer 28 with a nozzle head 30, a mixing chamber 32 and a settling chamber 34. The nozzle head 30 is advantageously designed as described in WO 2004/024 306 A1. Accordingly, it comprises a nozzle ring gap 36, which communicates with the water-side connection 12 via a water supply line 38, and gas injection nozzle 40, which is arranged in a central core 41 and communicates with the gas-side connection 14 via a gas supply line 42. The width of the nozzle ring gap 36 can be adjusted advantageously, in the mixing chamber 32, the centrally injected gas mixes extremely efficiently with the surrounding water flow to a water-gas mixture. This mixture then advantageously flows via micro-sieves 44 into the settling chamber 34. The micro-sieves 44 ensure a more homogeneous bubble formation in the liquid stream. The size of the gas bubbles in the water flow can also be controlled via the mesh size of the micro-sieves 44.

In contrast to the embodiment of the continuous mixer described in WO 2004/024306, the embodiment of the continuous mixer 20 shown in FIG. 1 has no pressure stabilizer at the outlet of the settling chamber 34. Rather, the gas-water mixture opens via a discharge opening 46 of the settling chamber 34 directly to a bleed line 48.

In the gas supply line 42, a pressure control valve 50 and a backflow preventer 52 are arranged. The pressure control valve 50 regulates the pressure difference between the gas in the gas supply line 42 and the water in the water supply line 38 to a constant setpoint, which may be zero in particular. For this purpose, an actuator 54 (piston or diaphragm) of the pressure regulating valve 50 is acted upon by the water pressure in the water supply line 38 and the gas pressure in the gas supply line 42. If the difference between the gas and water pressure exceeds a predetermined setpoint, the gas flow in the gas supply line 42 is throttled via a gas valve 56 connected to the actuator 54. If the difference between gas and water pressure falls below the predetermined setpoint value, then the gas valve 56 becomes opened again accordingly. A constant desired value for the pressure difference can be predefined via a spring means 58, for example. By selecting the bias of the spring means 58, one can adjust the predetermined setpoint for the pressure difference; wherein, depending on the arrangement of the spring means 58, the gas pressure may be higher or lower than the water pressure.

However, it is also possible to use a pressure regulator with a fixed pressure differential setpoint. Furthermore, it is also possible to dispense entirely with the spring means, since spring products often have a large dispersion as a result of their manufacture, can fatigue prematurely or break, and can bring about hygienic disadvantages.

A special case in this case is a pressure regulator with a pressure regulating piston which has a C 1 transformation ratio of 1: 1 and no spring means for prescribing a pressure difference. Such a pressure regulator then ensures that the gas pressure in the gas supply line 42 is approximately equal to the water pressure in the water supply line 38. He also has hygienic advantages over such pressure regulators, which have spring means, since in these the spring means often comes into contact with liquid and thus may be a source of nucleation.

If you want to set a (dynamic) water pressure in the flow mixer 28, which is lower than the gas pressure in the flow mixer 28 in this pressure regulator, so you can, for example. reduce the width of the nozzle ring gap 36 or install an (adjustable) throttle valve (not shown) in the water supply line 38 between the pressure regulator 50 and the flow mixer 28. On the other hand, if the water pressure in the continuous mixer is to be higher than the gas pressure in the continuous mixer (this may for example be the case with a venturi mixer), e.g. Install a throttle means (not shown) in the gas line 42 between the pressure regulator 50 and the flow mixer 28. Such throttling means may e.g. Apertures and / or throttle valves.

By the reference numeral 52, a backflow preventer is shown, which ensures that no water penetrates into the gas supply line 42, for example, if the gas pressure in the gas supply line 42 falls below the water pressure in the flow mixer 28. The latter is the case, for example, if the gas container is largely empty. Of course, the puncture of the backflow preventer 52 can also be integrated with the pressure control valve 50. The latter also applies to the safety function of the safety valve 24 described above.

In the bleed line 48, downstream of the continuous mixer 28, a simple flow rate regulator 60 is arranged, the flow rate of the drinking water flow in the dispensing line largely independent of pressure fluctuations, e.g. keeps constant in the fresh water supply.

By combining a constant maintenance of the pressure difference between the gas in the gas supply line 42 and the water at the water supply 38 via a regulation of the gas supply pressure on the one hand with a constant flow rate in the bleed line 48 by means of a simple flow rate controller 60 on the other hand can be a very uniform and achieve stable set carbonation. If the flow rate regulator is adjustable, the degree of carbonation can also be selected by the user.

Even with strong pressure fluctuations in the drinking water pipe, especially during short tapping operations, the carbonation always works optimally without any readjustments.

Surprisingly, it has also been found that even with very simple flow rate regulators, as e.g. under the name "water saver" are used as standard inserts in sanitary fittings, amazingly good results can be achieved.

The results obtained were surprisingly even better than with elaborate water-side pressure controls, with which one has previously tried to regulate a constant water pressure and / or gas pressure in the continuous mixer. Such simple flow rate regulators are based, for example, on the functional principle that an O-ring is arranged around a central regulating body with longitudinal grooves in a through-passage in such a way that it is deformed by the pressure difference between the water inlet side and the water outlet side and into the longitudinal groove. len of the control body is pressed. With increasing flow pressure (ie increasing flow or liter volume), the O-ring thus reduces the free flow cross-section of the longitudinal grooves in the central control body. With decreasing flow pressure (ie decreasing flow or liter amount), the O-ring returns to its original shape, whereby the free flow cross-section of the longitudinal grooves increases again.

Such "water saver inserts" are not only extremely inexpensive, but also long-term proven as standard inserts in sanitary fittings.In addition, these inserts can be very easily installed in the tap line 48 or the nozzle 26. There are also adjustable flow regulator central control body with the longitudinal grooves, for example conical and adjustable relative to the O-ring.

With the continuous mixers of the type described above in FIG. 1, exceptionally good carbonization results were achieved with the combined differential pressure / flow rate control in extensive tests. However, it is to be understood that also with other continuous mixers, such as e.g. Venturi mixers or continuous mixers with sieve inserts, by combining a constant balance of the pressure difference between the gas in the gas supply line 42 and the water in the water supply 38 via a regulation of the gas supply pressure on the one hand with a constant water flow in the tap by means of a simple flow regulator 60 on the other hand, a significant improvement of the carbonation result can be achieved. The degree of carbonization (carbonization performance) is hereby set in an extremely simple manner, reliably and stably by the pressure difference between the gas and the water in the continuous mixer 28 and by the flow rate preset by the flow regulator 60.

In the continuous mixer 28, it is also possible to influence the carbonization via the adjustable width of the nozzle ring gap 36.

Claims

claims

A process for the enrichment of a liquid stream with a gas, wherein: a. the liquid stream is passed through a continuous mixer (28); the gas is fed to this continuous mixer (28) so that it mixes with the liquid stream; and b. the feed pressure of the gas is controlled such that the pressure difference between the liquid flow and the gas fed in is substantially constant,

characterized in that

c. the flow rate of the liquid or water stream is kept substantially independent of fluctuations in the water or liquid pressure.

2. The method according to claim 1, characterized in that the flow rate of the liquid flow through a downstream of the continuous mixer (28) arranged flow rate regulator (60) is kept constant.

3. The method according to claim 2, characterized in that the flow rate regulator (60) is adjustable.

4. The method according to claim 1, characterized in that the pressure difference between the liquid flow and the injected gas is adjustable.

5. The method according to claim 1, characterized in that the pressure difference between the liquid stream and the injected gas is substantially zero.

6. The method according to claim 1, characterized in that the flow rate of the liquid flow through an upstream of the Durchstr. run mixer (28) arranged throttle is kept constant.

7. The method according to claim 6, characterized in that the throttle is adjustable.

8. The method according to claim 1, characterized in that the liquid flow through a tubular continuous mixer (28) having a nozzle head (30), which has a nozzle ring gap (36) with variable gap width, is passed.

9. An apparatus for enriching a liquid stream with a gas, comprising: a. a continuous mixer (28) having a fluid flow port (12), a gas port (14), and an enriched fluid flow port (16); and b. a differential pressure regulator (50) for controlling the gas pressure in response to the fluid pressure such that the pressure difference between the fluid flow and the injected gas is substantially constant;

marked by

c. a flow regulator (60) for keeping constant the flow rate of the liquid flow largely independent of pressure fluctuations.

The apparatus of claim 9, wherein the flow regulator (60) is located downstream of the continuous mixer (28).

11. The apparatus of claim 9 or 10, wherein the flow rate regulator (60) comprises a throttle body, which is arranged in a flow area of the flow rate regulator such that it reduces the flow area, if the pressure in the liquid flowing through it increases and increases the same if the Pressure drops in the liquid flowing through it.

12. The apparatus of claim 11, wherein the throttle body is an elastically deformable body which is deformable by the differential pressure acting on it.

13. The apparatus of claim 12, wherein the Drosselköper is an O-ring which is arranged in the passage to a central control body with longitudinal grooves such that it is deformable by the pressure difference between the inlet and outlet side of the liquid flow and pressed into the longitudinal grooves of the control body ,

14. Device according to one of claims 9 to 13, wherein the continuous mixer (28) comprises a nozzle head (30) and an adjoining mixing chamber (32), and the nozzle head (30) has a nozzle ring gap (36) and a central to the nozzle ring gap (36 ), wherein the connection for the liquid flow (12) with the nozzle ring gap (36) and the connection for the gas (14) with the Gaseinblasdüse (40) is connected.

15. The apparatus of claim 14, wherein the width of the nozzle ring gap (36) is adjustable.

16. Device according to one of claims 9 to 15, wherein the differential pressure regulator (50) is fixed to a pressure difference of about zero.

17. Device according to one of claims 9 to 15, wherein the differential pressure regulator (50) and / or the flow rate regulator (60) are adjustable.

18. Device according to one of claims 9 to 17, wherein the connection for the liquid flow (12) with a drinking water line (18) and the connection for the gas (14) via the differential pressure regulator (50) are connected to a carbon dioxide bottle (22), and the dispensing connection (16) is connected to a dispensing valve (26) via the flow regulator (60).