APPARATUS FOR DISSOLVING GASES IN LIQUIDS

Abstract: The invention relates to an apparatus for dissolving gases in liquids, comprising a chamber (1) which is open on one side and whose opening faces downwards in the operating position. The chamber (1) has at its upper end in the operating position at least one liquid admission port which opens into the chamber, whereby an additional element (3) is arranged in the chamber (1) such that there is a gap (8) between the additional element (3) and the chamber (1). Liquid introduced through the admission port rotatingly flows through the gap and along the chamber wall such that a gas bubble located under the additional element (3) cannot escape upwards through said gap (8) but is held in its position by said rotational flow.

Description: APPARATUS FOR DISSOLVING GASES IN LIQUIDS Field of invention The invention relates to a novel apparatus for dissolving gases in liquids, particularly an apparatus for continuously enriching aquarium water with C0 2 gas. Background of the invention Various types of gas diffusion devices for gassing aquarium water have been known from prior art. They include porous discharge devices through which the gas is introduced di¬ rectly into the liquid. The disadvantage thereof is, however, that these discharge devices only have a short gas/liquid contact time, i.e. the time of contact is only as long as it takes for the gas bubble to rise from the discharge device to the surface where the remaining gas contained in the bubbles is given off to the atmosphere. DE-A-31 17 797 describes an apparatus for the carbonation of aquarium water, which comprises an enrichment column. The column is provided with a contact and swirl chamber upwardly confined by a partition wall having a through-hole for the gas passage and a throughflow swirl pipe socket. Immediately below the partition wall the C0 2 gas bubbling up from the gas feed pipe connected at the bottom is collected. The aquarium water flowing through the enrichment column is swirled while it passes through the swirl pipe socket, getting into contact with the C0 2 gas collecting below the partition wall. In this type of device, too, the residence time of the gas is relatively short. Systems have been developed which partially overcome these problems. European Patent EP-B1-0103685 refers to a supply device for enriching aquarium water with C0 2 gas, said device comprising several vessels which may be arranged one above the other. When introducing C0 2 gas into the bottom vessel the C0 2 gas overflowing through an overflow pipe can be collected in the vessel above in the manner of a pneumatic trough. Gas exchange takes place at the gas/water boundary surface in each of the units. The last-mentioned patent refers to collecting chambers open at the bottom which are arranged underneath the liquid level. In the chambers, i.e. in each unit, a gas bubble collects from which the gas diffuses into the liquid. Utilization of gas in this case is improved due to the long residence time of the gas bubbles. However, absolute diffusivity is limited in said apparatus, as little or no water flows around the gas bubbles. A specific flow would flush the bubbles out of the collecting chambers, however. It is an object of this invention to provide an apparatus for dissolving gases which has a large gas/liquid diffusion surface and which is of small construction, and wherein the liquid advantageously flows around a gas bubble without washing it away. This object is accomplished by the apparatus as defined in independent claim 1. Further preferred configurations, aspects and details of the apparatus according to the invention can be seen from the dependent claims, drawings and preferred embodiments. Summary of the Invention According to a first aspect, the invention relates to an apparatus for dissolving gases in liquids, particularly for continuously enriching aquarium water with C0 2 gas. comprising a preferably cylindrical chamber which is open on one side, with the opening facing downwards in the operating position. The chamber has at least one liquid admission port, preferably a nozzle, in its upward end portion while in the operating position. The admission port opens into said chamber tangentially to the (cylinder) wall, and an additional element, preferably a plate-like element, is centrically arranged in said chamber such that there is a gap between said additional element and the chamber. Through said gap, preferably an annular gap, the liquid supplied through the admission port flows rotatingly along the chamber so that a gas bubble located underneath the additional plate¬ like element cannot escape upwards through the gap but is held in its position by said rotational flow. According to a second aspect, the invention relates to an apparatus for dissolving gases in liquids, particularly for continuously enriching aquarium water with C0 2 gas, comprising a preferably cylindrical chamber which is open on one side, the opening facing downwards in the operating position, wherein said chamber has at least one liquid ad¬ mission port in its end portion which faces upwards in the operating position. The admission port opens into said cham¬ ber tangentially to the (cylinder) wall, and an additional element, preferably plate-like, forms the top cover such that there is a gap between the chamber and the cover. Liquid flows rotatingly through the admission port along the chamber wall so that a gas bubble located underneath the cover cannot escape upwards but is held in its position by said rotational flow. According to a third aspect, the invention relates to an apparatus for dissolving gases in liquids, particularly for continuously enriching aquarium water with C0 2 gas, comprising a preferably cylindrical chamber which is open on one side, the opening facing downwards in the operating position, wherein said chamber has at least one liquid ad¬ mission port in its end portion facing upwards in the oper¬ ating position. The admission port opens into said chamber tangentially to the (cylinder) wall, and an additional element, preferably a plate-like element, is centrically arranged in said chamber such that there is a gap between the element and the chamber. Through said annular gap the liquid supplied through the admission port flows rotatingly along the chamber so that a gas bubble located underneath the plate-like element cannot escape upwards through the annular gap but is held in its position by said rotational flow. Preferably one vent pipe opens into the chamber. The vent pipe has an open end which is disposed above the lower edge of said chamber and a second end which is connected with the admission channel such that at the connecting point there is a screen in the admission channel which generates a low pressure in the vent pipe caused by the water flow. According to a fourth aspect, the invention relates to an apparatus for dissolving gases in liquids, particularly for continuously enriching aquarium water with C0 2 gas, comprising a preferably cylindrical chamber which is open on one side, the opening facing downwards in the operating position. The chamber has at least one liquid admission port in its end portion facing upwards in the operating position, said admission port opening into said chamber tangentially to the cylinder wall. An additional element, preferably a plate-like element, is centrically arranged in said chamber such that there is a gap between said element and the chamber. The liquid supplied through the admission port flows through said annular gap and rotatingly along the chamber so that a gas bubble located underneath the plate-like element cannot escape upwards through the annular gap but is held in its position by said rotational flow. Around the chamber there is provided another, preferably cylindrical housing member open at the bottom, which communicates with the admission channel through an opening such that at the place of the opening there is a screen in the admission channel which generates a low pressure in the gap between the chamber and the housing member, said low pressure being caused by the water flow. The present invention refers to a substantially improved apparatus for dissolving gases in liquids, specifically for the carbonation of aquarium water. In particular, the appa- ratus is adapted to continuously enrich aquarium water with C0 2 gas. The apparatus comprises a chamber which is open on one side, the opening facing downwards in the operating position. The chamber may be of any suitable shape, cylindrical chambers being particularly preferred. Liquid admission ports open into the chamber preferably tangentially to the chamber wall. The chamber has at its upper end in the operating position a top cover preferably including at least one connecting piece and at least one admission channel as well as at least one liquid admission port, e.g. one or several nozzles opening into said chamber. The cover may also be divided so as to facilitate manufacture and maintenance. In said chamber, an additional element whose diameter is somewhat smaller than the inner diameter of the chamber is arranged such that there is a gap between the chamber wall and the additional element. In preferred embodiments, the chamber is cylindrically shaped and the central element is plate-like. The annular gap is formed between said plate¬ like element and said cylindrical chamber through which gap the liquid supplied through the admission port rotatingly flows along the chamber wall. Preferred embodiments comprise a downwardly projecting en¬ largement on the lower edge of the additional element. In further preferred embodiments, the plate-like element is conically shaped, for instance. In still further preferred embodiments the additional element is held centrically in the chamber by a gas-supplying element. It is particularly preferred that said additional element does not touch the inner wall of the chamber. The gas-supplying arrangement may be a pipe portion. The additional element and the gas-supplying element may be composed of one or several parts, preferably two parts. The gas can be passed underneath the additional element via a gas-supplying pipe connection and the gas-supplying pipe portion. The liquid to be gassed is introduced in the ad- mission channel via a connecting piece and from there flows through the admission port(s) rotatingly along the chamber wall. When the whole surface of said additional element is com- pletely covered with gas from below, additionally supplied gas is prevented from rising by the water flowing downward through the gap. The circulating flow permits the formation of a large gas bubble which closely abuts the chamber wall and is kept stably in its position by the water film (rotational flow) circulating between the chamber wall and the gas bubble. In the case of an open water tank, for instance, further gases, mainly nitrogen and oxygen, are dissolved in the water. When the apparatus according to the invention is used in an open water tank, said further gases dissolved in water diffuse into said gas bubble until the partial pressure ratio of said gases in the gas bubble corresponds to the partial pressure ratio of the air. Hence, even if the supplied C0 2 gas is continuously dissolved in the water, the gas bubble will increase as long as C0 2 is supplied until the gas bubble finally reaches the lower edge of the chamber. In order to prevent the gas mixture emerging underneath the edge of the chamber from rising upwards in large bubbles, various preferred solutions are presented in the following preferred embodiments. The apparatus is preferably arranged within a liquid container underneath the liquid level. It may be attached to the inner wall of the container by holding means, such as suction cups or screw clips, for instance. In particularly preferred embodiments, the chambers are made of plastics, preferably transparent plastics. The individual components are also preferably made of plastics, especially transparent plastics. Brief description of the drawings Fig. 1 is a side view of the apparatus according to the present invention comprising a centrically arranged (cone- shaped) plate-like element. Fig. 2 is a top view of the apparatus of Fig. 1. Fig. 3 is a partially sectional three-dimensional represen- tation of a preferred embodiment of the apparatus of the present invention comprising a plate-like element serving as top cover. Fig. 4 is a side view of another embodiment of the present invention comprising a vent pipe. Fig. 5 is a top view of the embodiment of Fig. 4. Fig. 6 is a side view of another embodiment of the present invention comprising an additional cylindrical housing mem¬ ber. Fig. 7 is a top view of the embodiment of Fig. 6. Description of the preferred embodiments Fig. 1 shows a preferred apparatus for the carbonation of aquarium water. The apparatus according to the invention comprises a chamber 1 which is of a cylindrical shape and open on one side, the opening of which faces downward in the operating position. At the top end in the operating position there is a cover 12. One or several nozzles 2 are tangentially arranged in said cover 12, through which nozzles 2 the water or some other liquid to be gassed is supplied and a circulating flow is generated. The nozzles 2 are connected to a suitable circulation pump (not shown) via a connecting piece 7. The liquid to be gassed is introduced in the ad¬ mission channel 14 via the connecting piece 7 and is passed to the nozzles 2. The chamber 1 contains a plate-like ele¬ ment 3, which is arranged centrically therein. The diameter of said plate-like element 3 is somewhat smaller than the inner diameter of the chamber so that there is an annular gap 8 between the plate-like element 3 and the chamber 1. The plate-like element 3 does not touch the inner wall of the chamber 1. In the preferred embodiment shown in Fig. 1, an enlargement 4 projects downwards from the outer edge of said plate-like element 3. The plate-like element 3 is held by a pipe portion 5 such that it does not touch the inner wall of the chamber 1. C0 2 or some other gas is continuously passed through said pipe portion 5 under the element 3. The enlargement 4 facilitates the accumulation of gas bubbles under the plate-like element 3, without said bubbles escaping immediately upwards over the edge of the plate. According to Fig. 1 the plate-like element is conically shaped. The gas is introduced via a gas-supplying pipe connection 6 which opens directly into the pipe portion 5. When the entire surface of the plate-like element 3 is completely covered with the supplied gas from below, additionally supplied gas is prevented from rising through the annular gap 8 by water flowing downwards through the annular gap 8, said water having been fed into the annular gap 8 through the nozzles 2. Hence, a large gas bubble 9 can form under the plate-like element 3 on account of the circulating flow, which bubble closely abuts the chamber wall 1' and is held in its position by the water film circulating between the chamber 1 and the gas bubble 9. The water film and the lower side of the gas bubble form the exchange surface around which the liquid flows and through which the gas diffuses into the water (or any other liquid to be gassed) . The large water/gas exchange surface is a particular advantage of the apparatus according to the invention. When the apparatus of the invention is used in an open water tank, further gases dissolved in water, mainly nitrogen and oxygen, also diffuse into the gas bubble 9 until the partial pressure ratio of said further gases in the gas bubble corresponds to the partial pressure ratio of the gases in the air. For this reason, the gas bubble 9 also grows when the C0 2 gas is continuously dissolved in water, until the gas bubble 9 reaches the lower edge 11 of the chamber 1. In order to prevent the gas from emerging underneath the lower edge 11 of the chamber and rising upwards in large bubbles when the bubble grows larger, the preferred embodiment according to Fig. 1 incorporates a vent opening 10 in the chamber wall closely above the lower edge 11. As soon as the growing gas bubble reaches the vent opening 10, the excess gas can escape in small bubbles through said vent opening 10. A further vent opening 33 is shown in the cover (Fig. 1). Hence, uncontrolled fluctuations in the carbonation process is avoided. The apparatus can be attached to the walls of an aquarium by the holding means 15. Fig. 2 is a top view of the apparatus of Fig. 1, illustrat¬ ing the positions of the gas-supplying pipe connection 6, the nozzles 2, the connecting piece 7 and the admission channel 14. A further preferred embodiment is shown in Fig. 3. The embodiment of Fig. 3 comprises a preferably cylindrical chamber 1 defined by the lower edge 11 of the chamber and a vent opening 10 closely above the lower edge of the chamber. In contrast to the preferred embodiment according to Fig. 1, in this embodiment the gas is passed through the gas- supplying pipe connection 6 directly underneath the top cover 12 of the chamber 1, i.e. in this embodiment the function of the top cover 12 corresponds to the plate-like element 3. Hence, there is no plate-like element as in the embodiment illustrated in Fig. 1. Between the top cover 12 and the chamber 1 there is an annular gap 13 comparable to the annular gap 8 of Fig. 1. The water (or any other liquid) to be gassed is introduced through connecting pieces 7 and flows into one or several admission channels 14 which open tangentially into the an¬ nular gap 13 (indicated by arrows). In this embodiment, as in the previous embodiment, a gas bubble 9 forms under the cover 12, said bubble being separated from the chamber wall 1' merely by a circulating water film. As in the embodiment of Fig. 1, the vent opening 10 of this embodiment also serves to prevent the excess gas from escaping in large bubbles over the lower edge 11 of the chamber 1 when the bubble 9 grows larger and ensures that the gas escapes in small bubbles through the vent opening 10. The liquid to be gassed is supplied by means of supply pipe connecting pieces 7 e.g. via a circulation pump. The water passes through the supply pipe connecting pieces 7 into the admission channels 14 and to one or several nozzles 2 which are tangentially arranged. From there the liquid is fed into the annular gap 13. For circulating the water, a sufficiently high pressure has to be applied. The gas is passed through the gas-supplying pipe connection 6 directly under the top cover 12. The liquid flowing through the annular gap prevents the gas from entering said gap. The growing bubble 9 is thus also held stably under the top cover 12 by the circulating water flow. The preferred embodiment can be attached in the aquarium by holding means 15. A particular advantage of this embodiment resides in the fact that the plate-like element also forms the cover 12 of the chamber, which leads to easier handling of the chamber in cleaning operations. Another preferred embodiment is shown in Fig. 4. As com- pared to the embodiment of Fig. 1, this apparatus comprises additional features. It is provided with a vent element, namely a vent pipe 20. In a particularly preferred config¬ uration, said vent pipe 20 extends within the gas pipe por¬ tion 5. The upper end of the vent pipe 20 is connected to the admission channel 14 via a connecting element, i.e. a connecting pipe or tube 21. At the connecting point between the connecting element 21 and the admission channel 14 there is a screen 22 which generates a low pressure in the vent pipe 20 caused by the water flow. When the growing gas bubble 9 reaches the lower end 23 of the vent pipe 20, gas is sucked from the bubble 9 into the admission channel 14 due to the low pressure and is distributed in the form of fine bubbles in the supplied stream of water. The preferred embodiment preferably comprises an intermediate cover 25. The gas bubbles dispersed in the stream of water accumulate under said intermediate cover 25 after passing through the nozzles. When the gas bubble generated there has grown so large that it reaches the vent opening 24, fine gas bubbles can escape through the vent opening 24 into the atmosphere. A particular advantage of this embodiment resides in the fact that the excess gas escaping from the large gas bubble 9 is better utilized as it is again introduced via the con¬ necting element 21 into the admission channel 14; there and under the intermediate cover it again gets into contact with the liquid to be gassed. Fig. 5 is a top view of the preferred embodiment of Fig. 4, comprising the connnecting piece 7, the admission channel 14, the vent pipe 20 connected to the admission channel 14 via a connecting element 21, and a screen 22 arranged in the transition part. The gas-supplying pipe connection 6 is also depicted. In another preferred embodiment according to Fig. 6, the cylindrical chamber 1 is surrounded by another housing member 30 which has an open bottom and is also of a cylindrical shape. According to further preferred embodiments, said housing member 30 may also have different suitable shapes. In the embodiment of Fig. 6, the lower edge 11 of the chamber 1 ends above the lower edge of said housing member 30. Accordingly, the growing gas bubble 9 first reaches the lower edge 11 of the chamber 1. The housing member 30 communicates with the admission channel 14 via an opening 31, a screen 22 being provided at the place of the opening 31 in the admission channel 14, said screen generating a low pressure caused by the stream of water in the gap 34 between the chamber 1 and the housing member 30. The liquid to be gassed is introduced into the admission channel 14 via the connecting piece 7, flows to the nozzles (not shown) and finally passes through the annular gap along the chamber wall. The gas is introduced through the gas-supplying pipe connection 6 and collects under the plate-like element 3. When the growing gas bubble 9 reaches the lower edge 11 of the chamber, the excess gas rises in the form of small bubbles 32 in the gap 34 between the chamber 1 and the housing 30. The rising bubbles 32 are sucked through the opening 31 due to the low pressure and are again passed into the admission channel 14. The liquid and the gas thus supplied again flow through the nozzles into the chamber, the gas preferably collecting under an intermediate cover 25. Upon reaching a vent opening 33, the excess gas can escape to the outside. This preferred embodiment has the particular advantage that the gas escaping from the large gas bubble 9 is excellently utilized in that under the intermediate cover 25 a gas/water exchange surface is formed again. The preferred embodiment is arranged in the vessel containing the liquid to be gassed by holding means 15. Fig. 7 is a top view of the preferred embodiment of Fig. 6. It illustrates the connecting piece 7 and the admission channel 14, the opening 31 and the screen 22 as well as the vent opening 33. In the middle the gas-supplying pipe con- nection 6 is depicted. Through the apparatus according to the present invention, the residence time of the gas in the water (or any other liquid in which the gas shall be dissolved) is increased. At the same time, the design of the apparatus helps to prevent gas bubbles from being flushed away by the stream of water. According to the invention, an advantageously large gas/liquid boundary surface is formed. On the one hand, the diffusion steps taking place at said boundary surface concern the dissolution of the supplied gas, e.g. C0 2 , in the liquid, e.g. water. On the other hand, further gases in the liquid which dissolve in the liquid when open vessels are used diffuse from the liquid into the gas bubble, which leads to an accumulation of "foreign gases" in the gas bubble. The gas escaping from the apparatus through the vent opening (10 in Figs. 1 and 3, 24 in Fig. 4, 33 in Fig. 1 and 6) thus contains a large amount of "foreign gas". Hence, the apparatus according to the invention permits both optimum utilization of the supplied gas and the cleaning of the circulated liquid from foreign gases. Due to the large gas/liquid boundary surface, both operations are highly effective. On account of the large gas/water boundary surface and thus the advantageously large gas exchange surface, the present invention makes it possible to use a relatively small apparatus. Another advantage resides in the fact that the apparatus according to the invention can easily be cleaned, e.g. from algae, because all parts have smooth surfaces and can easily be reached and handled. The apparatus according to the invention is particularly useful for carbonation in the case of large aquariums. C0 2 is required by water plants in the aquarium for photo synthesis. A C0 2 supply device according to Fig. 1 for aquariums of about 2000 1 may have the following dimensions, for instance: inner diameter of the chamber 1: approx. 45 mm diameter of the plate 3: approx. 42 mm total height: approx. 150 mm. The apparatus is advantageously mounted in a liquid container underneath the liquid level where it is attached to the inner wall of said liquid container with holding means, such as suction cups or screw clips. Many variations of the present invention will suggest themselves to those skilled in the art in the light of the above detailed description. Such obvious modifications and equivalent arrangements for such devices falling within the scope of the following claims should be considered to be part of the present invention. The above-mentioned preferred embodiments illustrate the invention. They are not intended to limit the claims in any manner.

Claims: CLAIMS We claim: 1. An apparatus for dissolving gases in liquids, comprising a chamber having an upper end and a lower end an opening on one side, said opening facing downwards in the operating position, said chamber having at its upper end in the operating position at least one liquid admission port which opens into the chamber, wherein an additional element is arranged in said chamber such that there is a gap between said additional element and the chamber, through which gap the liquid introduced through the admission port rotatingly flows along the chamber wall such that a gas bubble located under the additional element cannot escape upwards through said gap but is held in its position by said rotational flow. 2. An apparatus according to claim 1, wherein said apparatus is applied for continuously enriching aquarium water with C0 2 gas. 3. The apparatus according to claim 1, wherein liquid is water. 4. The apparatus according to claim 1, wherein the gas to be dissolved is C0 2 gas. 5. The apparatus according to claim 1, wherein the chamber open on one side is a cylindrical chamber. 6. The apparatus according to claim 1, wherein the additional element is arranged centrically in said chamber. 7. The apparatus according to claim 1, wherein the additional element is a plate-like element. 8. The apparatus according to claim 7, wherein the gap is an annular gap. 9. The apparatus according to claim 1, wherein gas can be continuously supplied under the plate-like element through a gas supplying element. 10. The apparatus according to claim 9, wherein the gas supplying element is a gas supply pipe. 11. The apparatus according to claim 10, wherein the plate¬ like element is held centrically in the chamber by the gas supply pipe. 12. The apparatus according to claim 1, wherein a downwardly projecting enlargement is formed on the lower edge of the additional element. 13. The apparatus according to claim 1, wherein the plate¬ like element is conically shaped. 14. The apparatus according to claim 1, wherein gas can be continuously supplied under the plate-like element through a gas supplying arrangement, said plate-like element being held centrically in the chamber by said arrangement, and an enlargement projecting downwardly on the lower edge of the plate-like element. 15. The apparatus according to claim 14, wherein the plate¬ like element is conically shaped. 16. The apparatus according to claim 1, wherein at least one vent opening is arranged above the lower edge of the chamber. 17. The apparatus according to claim 1, wherein the additional element also forms the top cover of the chamber in such a manner that there is a gap between the chamber and the cover into which the liquid flows through said at least one admission port. 18. The apparatus according to claim 17, wherein the additional element is a plate-like element and the gap is an annular gap. 19. The apparatus according to claim 17, wherein at least one vent opening is arranged above the lower edge of the chamber. 20. The apparatus according to claim 1, wherein a vent pipe opens into the chamber, the open end of said vent pipe being above the lower edge of said chamber and the other end of said vent pipe being connected to the admission channel such that at said connecting point in the admission channel there is a screen which generates a low pressure caused by the water flow in the vent pipe. 21. The apparatus according to claim 17, wherein a vent pipe opens into the chamber, the open end of said vent pipe being above the lower edge of said chamber and the other end of said vent pipe being connected to the admission channel such that at said connecting point in the admission channel there is a screen which generates a low pressure caused by the water flow in the vent pipe. 22. The apparatus according to claim 21, wherein a vent opening is disposed underneath an intermediate cover of the chamber. 23. The apparatus according to claim 22, wherein the vent pipe extends within the gas pipe. 24. The apparatus according to claim 1, wherein another housing member which is open at the bottom is arranged around the chamber, said housing member communicating with the admission channel through an opening such that at the place of the opening in the admission channel there is a screen which generates a low pressure in the gap between the chamber and the housing member, said low pressure being caused by the flow of water. 25. The apparatus according to claim 24, wherein said other housing member is cylindrical. 26. The apparatus according to claim 17, wherein another housing member which is open at the bottom is arranged around the chamber, said housing member communicating with the admission channel through an opening such that at the place of the opening in the admission channel there is a screen which generates a low pressure in the gap between the chamber and the housing member, said low pressure being caused by the flow of water. 27. The apparatus according to claim 26, wherein said other housing member is cylindrical. 28. The apparatus according to claim 1, wherein a vent opening leads through the cover of the chamber into the surrounding liquid. 29. The apparatus according to claim 20, wherein a vent opening leads through the cover of the chamber into the surrounding liquid. 30. The apparatus according to claim 24, wherein a vent opening leads through the cover of the chamber into the surrounding liquid. 31. The apparatus according to claim 1, wherein the individual components are made of plastic. 32. The apparatus according to claim 31, wherein the plastic is transparent plastic. 33. The apparatus according to claim 20, wherein the individual components are made of plastic. 34. The apparatus according to claim 33, wherein the plastic is transparent plastic. 35. The apparatus according to claim 24, wherein the individual components are made of plastic. 36. The apparatus according to claim 35, wherein the plastic is transparent plastic. 37. The apparatus according to claim 1, wherein holding means are provided for fixing the apparatus in a liquid container. 38. The apparatus according to claim 20, wherein holding means are provided for fixing the apparatus in a liquid container. 39. The apparatus according to claim 24, wherein holding means are provided for fixing the apparatus in a liquid container. 40. An apparatus for continuously enriching aquarium water with C0 2 gas, comprising a cylindrical chamber having an upper end and a lower end and an opening on one side, said opening facing downwards in the operating position, said cylindrical chamber having at its upper end in the operating position at least one liquid admission port which opens into the chamber, wherein said admission port opening into said chamber tangentially to the cylinder wall and a plate-like conically shaped element with a downwardly projecting enlargement on the lower edge is arranged centrically in said chamber such that there is an annular gap between said plate-like element and the chamber, through which annular gap the liquid introduced through the admission port rotatingly flows along the chamber wall such that a gas bubble located under the plate-like element cannot escape upwards through said annular gap but is held in its position by said rotational flow and a vent opening is arranged above the lower edge of the chamber. 41. An apparatus for continuously enriching aquarium water with C0 gas, comprising a cylindrical chamber having an upper end and a lower end and an opening on one side, said opening facing downwards in the operating position, said cylindrical chamber having at its upper end in the operating position at least one liquid admission port which opens into the chamber, wherein said admission port opening into said chamber tangentially to the cylinder wall and a plate-like element forms the top cover of the cylindrical chamber in such a manner that there is an annular gap between said chamber and said cover through which annular gap the liquid introduced through the admission port rotatingly flows along the chamber wall such that a gas bubble located under the plate-like element cannot escape upwards through said annular gap but is held in its position by said rotational flow and a vent opening is arranged above the lower edge of the chamber. 42. An apparatus for continuously enriching aquarium water with C0 2 gas, comprising a cylindrical chamber having an upper end and a lower end and an opening on one side, said opening facing downwards in the operating position, said cylindrical chamber having at its upper end in the operating position at least one liquid admission port which opens into the chamber, wherein said admission port opening into said chamber tangentially to the cylinder wall and a plate-like conically shaped element with a downwardly projecting enlargement on the lower edge is arranged centrically in said chamber such that there is an annular gap between said plate-like element and the chamber, through which annular gap the liquid introduced through the admission port rotatingly flows along the chamber wall such that a gas bubble located under the plate-like element cannot escape upwards through said annular gap but is held in its position by said rotational flow and a vent pipe opens into said chamber the open end of said vent pipe being above the lower edge of said chamber and the other end of said vent pipe being connected to the admission channel such that at said connecting point in the admission channel there is a screen which generates a low pressure caused by the water flow in the vent pipe. 43. An apparatus for continuously enriching aquarium water with C0 2 gas, comprising a cylindrical chamber having an upper end and a lower end and an opening on one side, said opening facing downwards in the operating position, said cylindrical chamber having at its upper end in the operating position at least one liquid admission port which opens into the chamber, wherein said admission port opening into said chamber tangentially to the cylinder wall and a plate-like conically shaped element with a downwardly projecting enlargement on the lower edge is arranged centrically in said chamber such that there is an annular gap between said plate-like element and the chamber, through which annular gap the liquid introduced through the admission port rotatingly flows along the chamber wall such that a gas bubble located under the plate-like element cannot escape upwards through said annular gap but is held in its position by said rotational flow and another cylindrical housing member which is open at the bottom is arranged around the chamber said housing member communicating with the admis¬ sion channel through an opening such that at the place of the opening in the admission channel there is a screen which generates a low pressure in the gap between the chamber and the housing member, said low pressure being caused by the flow of water.

Inventors: GRIESINGER RALPH-EDGAR, RICHTER ARNO, GRIESINGER, RALPH-EDGAR, RICHTER, ARNO
Applicants: WARNER LAMBERT CO, WARNER-LAMBERT COMPANY
Application year: 1995
Main classification: A01K63
IPC codes: A01G7, A01K63, B01F1, B01F3