FI75743B - ANALIFICATION OF DIFFUSION AV GASER I VAETSKA. - Google Patents

Description

χ 75743

Apparatus for metered diffusion of gases into liquids Anordning för doserande diffusion av gaser i vätska

The invention relates to a device for diffusing gases in doses to liquids, the device consisting of a gas-filled, liquid-flushed diffuser, open at the bottom, which can be filled with a gas through a self-regulating pressure control valve connected to the diffuser .

Such diffusion devices are used, for example, in chemical technology and water purification. They usually include a liquid-flushed cylindrical diffuser that is filled with the desired gas through an inlet device. In this case, an interface is formed in the diffuser, through which the gas is diffused into the liquid.

A preferred embodiment of such devices is adapted for small-scale use in aquariums, where the dispensed enrichment of the aquarium water with carbon dioxide (CO2) is a particular problem. In addition to acting as a plant nutrient, carbon dioxide acts as a chemical equilibrium component in aquarium water in the bicarbonate-carbonic acid system, the optimal regulation of which is of great importance for the life of the aquarium. The need for free carbon dioxide is determined by the water volume of the aquarium, the number of plants, the quality and the intensity of the light that provides the connection, and the natural amount of carbon dioxide (carbonate hardness). CC> 2 “The supply control can be monitored by measuring the pH of the water.

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One known device for diffusing CC> 2 in aquariums comprises a diffusion cylinder mounted in a vertical position next to the inner wall of the aquarium by means of a suction cup system, for example two side-mounted suction cups. The upper end face of the diffusion cylinder is made into a diffusion membrane, through which the gas dissolves immediately in water. In addition, the film must be completely covered by water and preferably located about 4 cm below the surface of the water. The diffusion cylinder is filled near the membrane through a hose nipple formed in the cylinder shell. During the filling phase, the CO 2 overpressure displaces the water in the diffusion cylinder.

In addition, a bottom opening is made in the end face opposite to the membrane, through which the water in the pressure equilibrium flows back during the gradual diffusion loss of CC> 2. To monitor the liquid level, the diffusion cylinderÖ is made of glass or transparent plastic. Filling is done in batches manually via a control valve in which a CC> 2 cartridge is placed. Such a diffusion cylinder must be filled with CO2 at least once a day.

There are several disadvantages to such a diffusion device. First, the size of the diffusion membrane is determined by the structure, so that the diffusion rate can only be adjusted in parallel by accurately connecting several diffusion cylinders according to the actual CO2 demand. Adapting to changing CO2 needs requires costly and disruptive changes to the aquarium. Second, according to the basic information of the present invention, the diffusion phenomenon is most complete at high pressure, which loads the gas-liquid boundary layer. However, in said known embodiment, the diffusion membrane is located close to the surface of the water, i.e. in the region of the lowest water pressure. Measurements in a known diffusion cylinder gave the surprising result that at least CO2 diffusion does not occur on the membrane, but on a pressure-stabilized gas-water layer at the bottom of the gas column. Finally, manual filling of a diffusion device according to the state of the art always requires the attention of the person operating the device. However, such use for commercial breeding or cultivation aquariums as well as decorative aquariums in commercial apartments and restaurants is hardly a prerequisite. Manual filling of the diffusion cylinder always causes large fluctuations in the liquid surface as well as occasional irregularities which adversely affect the invariance of the CO2 ~ diffusion rate.

It is an object of the present invention to provide a device of the type initially described which is convenient, easy to maintain and easily adjustable and in which the amount of diffusion can be varied without extensive reconstruction and thus to adapt the device to dynamically changing needs.

According to the invention, this object is achieved in that the pressure control valve closes on the inlet pressure side by means of a miniature valve which is operated by a pressure spring-loaded an axially movable sponge-shaped pressure member on a resilient, plate-shaped diaphragm that tightly encloses the control pressure range of the pressure control valve.

Preferred embodiments of the device according to the invention are defined in the subclaims.

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The device according to the invention has abandoned an expensive diffusion membrane, which, moreover, in the biologically active environment of the aquarium is constantly exposed to the harmful effects caused by suspended particles and flora and must be cleaned regularly. The design of the diffuser according to the invention makes it possible to determine the size of the effective diffusion interface between the gas and the liquid, taking into account the average control gas pressure. The diffusion interface is thus adjustable thanks to the pre-setting of the average gas pressure, and the gas pressure can be automatically compensated by means of a pressure control or pressure reduction valve in the vicinity of the preselected average. In addition, the shape of the diffuser can be varied within wide limits, depending on the desired setting range. After the adjustment has taken place, the desired pressure can be kept constant for a long time with minor adjustment movements. The automation according to the invention for self-filling the diffuser allows for the first time a pressure adjustment with an accuracy of ± 10 mb. The diffuser thus constructed can be placed on the bottom of the aquarium so that the gas outlet is located in the vicinity of the bottom. The advantage of this is that C (? 2 is introduced into the root region of the plants, which has a beneficial effect on growth.

The invention will be described in more detail below with reference to the drawings of an embodiment, in which Fig. 1 shows a section of a diffuser according to the invention and Fig. 2 shows a larger axial section of a very advantageous pressure control valve connected in front of the diffuser.

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The diffusion theory 1 is an open hollow body at its lower end. Its design is adapted to the desired change in the effective diffusion surface affected by the set control gas pressure. Figure 1 shows an embodiment with a conically downwardly expanding outer shape, and thus in which the increase in the control pressure changes according to the size of the diffusion surface. The diffuser 1 is preferably placed under the bottom of a liquid tank, for example an aquarium (not shown).

In the illustrated embodiment, the conical part 2 of the diffuser 1 is associated with a cylindrical edge part 3 through which large-area openings 4 are pierced. Through these openings 4, the inner part of the diffuser 1 communicates with the surrounding liquid. The upper edge 5 of the openings 4 limits the highest liquid surface of the diffuser 1 with the gas. The jacket surface between the openings 4 between the openings 4 forms a row of legs 6 which ensure a sufficient distance between the bottom of the liquid tank (not shown) and the highest liquid surface of the diffuser 1 and thus an unobstructed liquid exchange. Instead of the openings 4 in the cylindrical edge part 3, notches, support nozzles, etc. (not shown) can be made in the lower edge of the diffuser 1.

The conical shape shown facilitates the attachment or anchoring of the diffuser 1 to the bottom of the tank for use in aquariums. In this simple way, the diffuser 1 can be tilted between the stones arranged on the side and thus at the same time covered. In support of the heavy material, the proximal edge portion 3 of the bottom of the diffuser 1 may be provided with a rotating or discontinuous flange-like protrusion 7. Alternatively or in addition, other protrusions 7 'may be formed on the outer casing of the diffuser 1 and the upper edge of the diffuser 1 may be formed as a support surface. According to the embodiment, the lower edge of the diffuser is closed by a removably fitted or glued lid 8 ', so that the heavy material can also be placed inside the diffuser 1.

A connection 9 is made on the upper side of the diffuser 1, which conveys the gas inlet inside the diffuser 1. A hose 6 75743 (not shown) leading to the outlet side of the pressure control valve is pushed onto this connection socket 9. The diffuser 1 is preferably made in one piece from glass or transparent or translucent plastic.

The operating parts of the pressure control valve 10 (Fig. 2) are mounted in the valve housing 11. This is an open-ended, axially-symmetrical shaped part with a through-diameter, stepped axial bore 12. The housing 11 is formed by a base cylinder 13 and an associated conically tapered part 14 which in turn becomes cylindrical into a relatively small diameter housing extension 15. The axial bore 12 in this housing extension 15 is constricted approximately midway in height by a radial constriction 16 which divides the interior of the housing extension 15 into two chambers 17 and 18 of approximately equal size at the free end of the housing extension 15 the outer chamber 17 has a spring-loaded miniature valve 19 which is affected by the gas pressure on the inlet side. In contrast, the inner chamber 18 falls within the control pressure range of the pressure control valve 10. The control movement of all parts of this pressure control valve 10 takes place in the axial direction of the housing 11.

The miniature valve 19 includes an open-ended, through-drilled sleeve 20 coaxially fitted to the outer chamber 17 of the housing extension 15. The sleeve 20 rests tightly on the end face of the housing extension 15 by a radially outwardly projecting flange 21. The seal is a circular braid ring 22 pushed onto the sleeve 20 against the flange 21, which is pressed conically at the end of the axial bore 12 of the housing 11. The compression or contact pressure is transmitted by a cap nut 23 slidably resting on the rear surface of the flange 21, which is threaded in the external thread of the housing extension 15.

The axial extension is made integral with the sleeve 20, and the sleeve 20, when in place, protrudes over the cap nut 23 and allows a hose (not shown) leading to a pressure source, for example a CO 2 cartridge, to be inserted. The inner diameter of the connecting groove 24 is reduced with respect to the sleeve 20. The contraction point 25 forms a support for a compression or compression spring 26 fitted inside the sleeve 20. This compression spring 26 acts on a valve end 27 which is guided inside the sleeve 20 and is axially movably mounted. In this case, the axial movement is limited by a step 28 in the wall of the sleeve 20. A compression spring 26 is pushed around a pin 29 formed in the valve end 27. Due to the biasing of the compression spring 26, the valve head 27 rests tightly on the sealing ring 30. As a result, the inlet pressure range of the pressure control valve is insulated from the control pressure part. The sealing ring 30 is mounted on a sealing seat on top of the constriction 16, which constriction separates the chambers 17, 18 of the housing extension 15. The inner dimension of the sealing ring 30 then corresponds approximately to the inner diameter of the constriction 16.

The valve head 27 is raised from the control pressure side of the pressure control valve from its sealing position. In addition, there is a pressure sponge, i.e. a sponge-shaped pressure part 31, the cylindrical shaft of which slides axially in the inner chamber 18 of the housing extension 15. A pusher 32 is arranged on the end face of the shaft. The pusher 32 rests freely against the valve end 27. The sponge-shaped pressure part 31 is freely on a resilient membrane 35 which seals the control pressure part of the pressure control valve 10. The membrane 35 is formed by a circular membrane plate, which is held on the one hand by its shoulder edge by means of a shoulder 36 against the inner wall of the housing 11 and on the other hand by a retaining ring 37.

The diaphragm 35 forms the bottom of the conical housing part IA and is approximately planar when the miniature valve 19 is closed. The pressure plate 33 of the pressure part 31 covers the central area of the membrane 35 and is movable in the axial direction inside the conical housing part delimiting the membrane. The clearance of the pressure part 3 then corresponds at least to the control stroke of the miniature valve 19.

The membrane 35 is pressure-sealed between the retaining ring 37 and the housing 11. The retaining ring 37 is a fitting corresponding to the inner dimension of the basic cylinder 13. It is fitted in place relative to the housing extension 15 3 75743 on the opposite side of the housing 11 coaxially to the base cylinder 13, pressed against the resilient membrane 35 and held in place in the sealing position by one or more fixing screws 38.

The outside air side of the membrane 35 is loaded by a piston 39 which covers the entire surface of the membrane 35. The piston 39 is spring-loaded and axially movably mounted. For this purpose, a spacer 40 is moved into the retaining ring 37, which is displaced from the bottom inwards relative to the support surface of the pressure control valve 10. This spacer 40 has a central, axial threaded bore 41 into which a setting sleeve 42 is screwed. This setting sleeve 42 holds and guides 43 with axial 1 clearance. An axial impermeable bore 44 is provided in the piston rod 43, to which a compression spring 45 is fitted which acts on the bottom of the setting sleeve 42. The screwed-in depth of the setting sleeve 42 thus determines the force with which the piston 39 is pressed against the diaphragm 35.

The chamber 46 formed by the intermediate base 40 of the jacket and the retaining ring 37 and the membrane 35 communicates with the outside air via the threads of the setting sleeve 42. In this way, the pressure equalization is adequately ensured.

A degassing opening is made in the side 11 of the housing 11 of the pressure control valve. In the embodiment shown, in addition, a bore 47 is made through the wall of the housing 11 at the control pressure range of the valve. Connected to this bore 47 from the outside is a hose nose 48 having a rotating annular groove for the sealing ring 49 in the lower wall and a retaining collar 50 at the top. The end of the hose plug 48 expanded into a knob is provided with a thread into which a reduction screw 52 is screwed from the outside. The gas flow comes out substantially through the threads of the reduction screw 52 and is thus strongly throttled. The reduction screw 52 may be provided with one or more threads perpendicular to the requirements, as required

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9 75743 to provide lower flow resistance.

The operation of the pressure control valve 10 according to the invention is characterized by a balance of forces at the valve head 27, which must be raised from its sealing seat against the pressure on the gas inlet side and the prestressing of the compression spring 26. In addition, the pressure-affected surface on the inlet side of the low-power valve head 27 must be as small as possible, and the operation of the valve head 27 must be as smooth as possible. The spring-loaded piston 39 transmits the required driving force via a resilient diaphragm 35 to a sponge-shaped pressure part 31 which acts on the valve head 27 by means of a pusher 32. Until the control pressure decreases below a given value determined by the spring tension of the piston 39, this driving force is equalized to the large diaphragm the valve head 27 remains in the sealing position. The entered value is preselected by the setting sleeve 42. After the valve head 27 has risen, a sufficient pressure rise must occur in the control pressure range to prevent the gas from entering again. For this purpose, the outflow of gas from the control pressure range is prevented by strong throttling.

Thanks to the possibility of adjusting the pressure in the low-pressure range tolenransse11a to 10 mb, precise control of the liquid surface of the diffuser according to the invention has been achieved. The design features of the pressure control valve are then the use of a low-friction miniature valve on the gas inlet side, the use of a resilient diaphragm in the control pressure range and a strong reduction of the gas flow at the outlet.

The pressure control valve according to the invention is made for inlet pressures between 100 mb and 2b. In the application example shown, the gas is led to the pressure control valve via a hose plug. Any necessary pressure reducer, throttle valves and / or expansion chambers (not shown) separately pre-connected to the pressure control valve may, of course, also be connected in one piece to the pressure relief valve.

Il

Claims (7)

1. Apparatus for dispensing gases in ratios to external surfaces, the device consisting of a gas refillable through an inlet device, of a liquid rinsed, down to open diffuser (1), which can be filled with gas through an automatically adjustable pressure control valve (10), which valve is connected by a hose to a coupling plug (9) arranged opposite to the part of the diffuser (1) which is opposite to its open part, characterized in that the pressure control valve (10) is closed on the inlet pressure side with a miniature valve. (19), which can be driven by means of a compression spring loaded against a sealing ring (30) axially movable, with a sliding member (32) provided. valve head (27) under the influence of the control pressure and an adjustable bias, whereby on the end of the valve head (27) is arranged parallel to the sliding member (32), therewith an axially movable sponge-shaped pressure part (31), which rests on a resilient , disc-shaped diaphragm (35), which tightly closes the pressure regulating region of the pressure regulator valve (10). 2. Apparatus according to claim 1, characterized in that the relative pressure side (31) of the sponge-shaped pressure portion (31) of the diaphragm (35) can be loaded by an axially movable piston (39) with a determined force. Device according to claim 1 or 2, characterized in that the valve head (27), the sponge-shaped pressure part (31) and the cowl (39) are movable in the direction of the axis of the pressure valve (10) surrounding the housing (11) and that the diaphragm (35) at its peripheral edge is secured to an ahsäts' <6) in the inner wall of the housing (11). Device according to claim 2 or 3, characterized in that a tiling ring (37) adapted to the housing (11) presses the diaphragm (35) tightly against the shoulder (36) and that an intermediate bottom (40) is provided with a center in the pouring ring (37). a threaded bore (41) in which an adjustable sleeve (42) can be screwed in to