DE2223460A1 - Aeration diffuser - of modular construction for aerating polluted lakes,rivers etc - Google Patents

Abstract

Diffusion of a gas into a relatively large vol. of liq. partic. diffusion of air or O2 into polluted lakes or rivers deficient in dissolved O2, by delivering the gas into the liq. via a small aperture, to form a small bubble which is driven into the mass of liq. before its formation is complete by a flow of liq. past the aperture at a speed which is pref. less than that of the liq. past the aperture.

Description

Method and device for gas diffusion in a liquid ========================================= == ~ =================== The invention relates to a method and a device for gas diffusion in a liquid, especially on the diffusion of small gas bubbles in a Liquid, e.g. for reactivating polluted lakes and rivers by blowing in of air or oxygen in the contaminated water.

The invention is therefore based on the object of soiled To regenerate water and to create a device for this.

According to the invention, a device for gas diffusion in a Liquid created, which is characterized by a channel with at least a small opening in part of its side wall, a device for generating it a gas flow through the small opening and into the channel to to form a small gas bubble at the opening, as well as by a device for Creating a flow of fluid through the channel to keep the bladder from shear off or cut off the opening.

According to the invention there is also a device for gas diffusion created in a liquid that is labeled through a Housing defining an elongated outlet opening, a device for generating a liquid flow through the elongated outlet opening in one Direction perpendicular to its longitudinal axis, a device that is a number smaller Opening along a longitudinally extending lateral part of the elongated Contains outlet opening and through a device for generating a gas flow through the series of small openings and into the outlet opening to small Forming bubbles, which from the longitudinally extending lateral part of the elongated outlet opening are sheared off by the liquid flow, which extends through the elongated outlet opening to thereby the To promote gas diffusion in a body of liquid outside the outlet opening.

According to the invention there is also a device for gas diffusion in a relatively large body of liquid or a relatively large amount of liquid provided, which is characterized by a housing arrangement which has a plurality limited parallel slots, a device for generating a liquid flow away from the housing assembly through the slots into the body of liquid into it, at a first rate, a device that has a multitude of small openings along at least a lateral part of each slot limited and a device for generating a gas flow with a second Speed through the small openings into the slots form a series of small gas bubbles at each small opening, the first Speed is greater than the second speed to allow the liquid flow in all slits shear or separate the bubbles and the same from the small ones Openings can be transported away before the next subsequent bubbles to the small openings are formed, thereby allowing gas diffusion in the body of liquid or is conveyed in the amount of liquid.

According to the invention there is also a method for gas diffusion into a relatively large body of liquid or a relatively large amount of liquid specified in, at de; the gas through at least one opening into the liquid is introduced to form a bubble at this opening, the bubble in front their complete formation by a liquid flow that occurs at the opening runs past, washed into the body of liquid or into the amount of liquid will.

The invention will now be explained in detail with reference to the accompanying figures described, all of which emerge from the description and the figures Contribute details or features to the solution of the problem within the meaning of the invention can and were included in the application with the will to be patented. 1 shows an oblique view of the diffuser device, which shows a number of units or modular elements constructed in accordance with the invention are; FIG. 2 is an enlarged partial sectional view taken along line 2-2 of FIG. 1 showing the relationship between the gas distribution devices or rails, one Water storage chamber and a number of outlet slots in one of the diffuser units illustrates; 3 is an enlarged side view taken along line 3-3 of FIG Fig. 2, the capillary tubes for the formation of gas bubbles-along the opposite Represents sides of an outlet slot; 4 is an enlarged partial view of a Part of a capillary tube shown in Figures 3 and 5 is a sectional view showing the construction represents a modified embodiment of the diffuser device.

Although the diffuser device 10 (Fig. 1) comes in many different Environments can be used, is in Fig. 1, the diffuser device on the Bottom or bottom 12 of a lake or a large amount 14 of polluted water shown. The polluted or polluted water has a lack of oxygen, and this hinders the normal regeneration processes that are required, to maintain fish life and proper sanitation in lake 14. By dissolving oxygen in the water, the natural processes of water purification become accelerated. U.S. Patent 3,505,213 entitled "Method and Apparatus for purifying a natural amount of water "is a method and an apparatus to support or supplement the natural water purification process Introduction of oxygen into the water described. Although it can be stated that that the diffuser device 10 can advantageously be used to reduce the absorption of oxygen (or other gases, e.g. air) through bodies of water or amounts of water to promote, it should be noted, however, that the diffuser device 10 is also used for this purpose can increase the absorption of other gases by other amounts of liquid support.

The diffuser device 10 includes numerous units or modular elements 18, which have parallel outlet openings or slots 20, from which one Mixture of water and small oxygen bubbles 22 (Fig. 2) enters the lake 14, to oxygenate the lake. These small oxygen bubbles 22 become distributed in a relatively large area of the lake 14 and slowly rise against the Surface of the lake. The bubbles should be as small as practically possible is to get maximum adsorption before the bubbles hit the water surface reach. If an oxygen bubble is relatively large, it rises quickly to the water surface and escapes into the atmosphere before the oxygen in the bladder from which water can be absorbed. If, on the other hand, the oxygen bubbles are relatively small, they slowly rise towards the surface of a body of water, so that there is more time for the oxygen to be absorbed.

In addition, smaller bubbles have relatively larger surface values per Oxygen unit in the bubbles, reducing the absorption of the gas by the Surfaces of the bubbles is supported. When the bubbles 22 rise, the Oxygen in the bubbles is absorbed by the deoxygenated water of the lake. There the oxygen bubbles 22 rise slowly and are quite small, being a have relatively large surface area per unit of oxygen contained in the bubbles practically all oxygen is absorbed when the small bubbles are slow climb up against the surface of lake 14. On the other hand, if the bubbles were relatively large, so they would rise quickly against the surface of the lake, leaving not enough time would be present to absorb the oxygen. This could lead to a gushing out or cause the oxygen to escape into the atmosphere. The escape of oxygen into the atmosphere naturally increases the costs that are incurred to achieve the desired oxygen content in the water of lake 14, and also this can cause a security problem.

The module elements or units 18 are through a main gas line 24 (Fig. 1) connected to a common source of oxygen under pressure. The main gas line 24 is through gas distribution rails 28 in each unit 18 Supply lines 30 connected. In addition, each unit 18 is through. a common Pipeline 32 fed with pressurized water on which the diffuser units 18 are fastened by a base plate 34. A pump 33 shown schematically may be associated with the pipeline 32 to draw water from the lake 14 and to drive through the pipe 32. To prevent solids from getting into the pump or reach the bus bars 28, a suitable filter may be provided.

So when the diffuser devices 18 are in use, to oxygenate the lake 14, the diffuser devices are through the gas line 24 continuously with gaseous oxygen and through the water line 32 continuously fed with water. Although the gas line 24 and the water pipe 32 in Fig. 1 is shown lying on the bottom 12 of the lake, If necessary, they can also be hung or otherwise above the bottom of the lake being held.

The modular elements 18 of the diffuser device can be extremely fine or create small bubbles that are distributed or dispersed in lake 14. the Bubbles 22 are formed on either side of the slots 20 through the gas distribution devices or rails 29 (see FIGS. 2 and 3) are limited. The small bubbles 22 become consequently formed in straight rows or series 42 and 44 (Fig. 3), the along the entire length of the opposing, longitudinally extending sides 46 and 48 of the slots 20 extend parallel to one another. These bubbles are going through Washed away water, which in a continuous flow from a chamber 49 (Fig. 2) flows through the slots 20 into the lake. The bubbles are washed away before they are fully trained. The water chamber 49 stands through channels (not shown) which extend through mounting plate 34 (Fig. i) are in fluid communication with the water pipe 32.

The flow of water from the slots 20 carries the bubbles over a relatively long distance into the lake. This leads to the formation of a "gas mist" or a cloud of bubbles extending a considerable distance from the Diffuser device 10 extends outwardly.

The bubbles 22 are at the open ends 54 of capillary tubes 58 which extend from the gas chambers 60 against the sides 46 and 48 of the slots 20 extend (see. Figures 2, 3 and 4!). All vertically arranged gas chambers 60 are in fluid communication with gas line 24 so that one is pressurized drawing continuous flow of gas from line 24 through one of the supply tubes 30 (Fig. 1) flows into each gas chamber 60. The gas also flows out of the chambers 60 by rows 62 and 64 (FIG. 3) of parallel capillary tubes 58 to the opposite sides 46 and 48 of the slots 20.

A single straight line or series of small gas bubbles is drawn along it each side 4, 6 and 48 of the slot 20 at the open ends 54 of the capillary tubes 58 trained. The open ends 54 of the capillary tubes 58 are along the sides 46 and 48 of the slot 20 closely spaced to accommodate the volume of water to keep to a minimum that one is required to distribute the gas bubbles 22 in the lake 14 required. Though only a single line or row of evenly spaced ones Capillary tubes 58 on either side of the slot 20 in the illustrated diffuser device a plurality of parallel lines or rows of capillary tubes can also be provided be arranged one behind the other on each side of the slot 20.

The open ends 54 of the capillary tubes 58 must have a small diameter exhibit when small bubbles as gas flows from the ends of the capillary tubes should be trained away. To the formation of the small gas bubbles as well as the To facilitate manufacture of the diffuser device 10, the capillary tubes are made 58 made of fiberglass tubing with cylindrical inner channels that have a diameter from 0.00025 to 0.00050 inches (0.0064 to 0.0128 mm). This straight forward Fiberglass pipes are relatively light in a parallel relationship to one another and in a perpendicular position with respect to the longitudinal axis of the slot 20 in FIG Embed support rails 66. This embedding of the capillary tubes 58 takes place by that one only positions the pipes in the desired position and a suitable one Allow sealing material to flow around the pipes. When the sealing material solidified, it connects the capillary tubes 58 in a sealed manner to one another, forms the rails 66 and prevent fluid flow around the tubes.

The small open ends 54 of the fiberglass tubes 58 allow Formation of vein-like small bubbles, i.e. 3lasen'in one Size range that is less than 0.004 inches (0.10 mm) in diameter. try in fact have shown that bubbles with a diameter in the range of 0.008 to 0.0010 inches (0.20 to 0.025 mm). As the capillary tubes 58 relatively thin and closely spaced over the entire lungs of the slot 20 Arranged from one another, there can be a large number of bubbles with a small diameter along sides 46 and 48 of slot 20 are formed. Although the Openings 54 made by drilling holes in or through the rails 66 can be that one made the rails from porous sintered metal has it was found that the capillary tubes 58 bubbles at a speed and of a uniform size that cannot be achieved with other designs will.

To transfer the small individual bubbles 22 from the capillary tube openings 54 to promote the lake 14, each bubble 22 is from a capillary tube opening 54, at which it arises, transported away from the opening before the formation of the next bubble. This is achieved by having a flow of water at a relatively high speed passed through the narrow slot 20 and gas at a slightly slower speed is passed to the open ends 54 of the capillary tubes 58. This causes a shear or separation process by which the bubbles are flushed away from the sapillary tubes.

Due to the difference in the flow velocities of the water and gas there is a sufficient amount of time in which each bubble 22 is removed from the Side of the slot 20 and separated from its associated capillary opening 54 can be carried away by the water flow before the next bubble is formed will. The slot 20 has a relatively small width to accommodate the flow volume of the fast flowing water through the slot to a minimum.

As mentioned above, the following applies: The smaller the bubble size is, the more effective the adsorption becomes. The illustrated diffuser device, which produces extremely small bubbles, therefore forms an effective or powerful one and safe system, which is due to the large amount of absorption before the bubbles reach or penetrate the surface of the lake.

As explained above, the following applies: The smaller the bubble diameter the slower the bubble rises.

The following also applies: the smaller the bubble, the higher it is the rate of absorption. For example, it has been found that a Bladder, when released in 10 feet (300 cm) of water, is the diameter of the bladder Must not exceed 0.007 in. (0.18 mm). A bubble this size has one Rate of climb of about 3 cm per second5 which means that the bladder 100 Meandering required to ascend a distance of 10 feet (300 cm). This same ~ bubble takes about 100 seconds to fully dissolve. These values indicate that to achieve 100% consumption of oxygen in a water depth of 10 feet (300 cm) the bubbles cannot be larger than 0.007 inches (0.18 mm).

Similar examples can also be found for other depths.

Because the bubble size that is needed to generate the necessary buoyancy needs, which overcomes the surface tension, which in turn attaches the bladder to the Capillary tube is larger than 0.02 in. (0.5 mm) in diameter it proved impossible to produce uniform bubbles of one diameter which is less than 0.02 in. (0.5 mm) by simply passing gas through a thin capillary tube can flow.

The 0.00025 inch (0.0064 mm), on the other hand, provide an extremely thin, straight, uniform gas passage hole. This uniform Create capillary openings due to their Forming uniform small bubbles. In addition, a saving is achieved on pumped water by making sure that all of the pumped water is across is passed over the bubble shear surface. This is due in part to the fact due to the fact that the diffuser is provided with a water slot that covers the entire Pumped water inevitably directs over the bubble shear surface.

In the device shown in Figures 1 to 4, the row of capillary tubes 58 arranged along both longitudinally extending sides of a slot 20 so that that a series of gas bubbles formed on opposite sides of the slot will. This supports effective mixing of the gas bubbles with the water while this flows through the slot 20 into the lake 14. The device shown in FIG is largely in the same way as the device according to the figures 1 to 4 and works accordingly. The diffuser device 70 of FIG However, FIG. 5 has a single row 72 of capillary tubes 74 running along it one side 76 of a slot 78 are arranged. The gas bubbles are therefore generated only along side 76 of slot 78. The side 80 of the slot 78 is not interrupted by capillary tube openings. Oxygen or another Gas is from a gas line (not shown) through a channel 82 into a vertical Chamber 84 is in fluid communication with the open ends of the capillary tubes 74 stands. The other ends of the capillary tubes 74 are along side 76 of the slot 78 arranged. A chamber 88 is through a channel 90 with no water pipe (not shown) connected so that pressurized water from the chamber 88 through-the Slot 78 flows past the open ends of the capillary tubes 74 and the gas bubbles shears or separates from the capillary tubes as soon as the bubbles form kick off.

It should be noted that the diffuser devices 10 and 70 are both elongated Openings or slots 20 and 78 having a width or gap width that During manufacture the diffuser devices easily adjusted can be made to the desired ratio between the width of the slits flowing water flow and the gas bubbles establish on the side of the slots be formed.

During operation of the diffuser devices 10 and 72 are on the open ends of the capillary tubes along the side walls of the slots Formed gas bubbles. Once the bubbles have formed, they will be removed from the sidewalls of the slots sheared off by a flow of water flowing through the Slots through into the lake from which the gas is to be absorbed. The speed of the water flowing through the slots is greater than the speed of the gas flowing through capillary tubes 58 and 74, so that each bubble of its associated capillary tube through the water flow passing through the slot is led away before the next gas bubble is generated on the capillary tube. These Gas bubbles are relatively small and rise so slowly that they move away from the diffuser be washed away over a relatively long distance into the lake. The relative low rate of rise of the gas bubbles and the fact that they have a relatively large distance away from the diffuser to be flushed to the outside, favors the absorption of the gas in the water # and reduces the gushing out of the gas into the atmosphere.

The diffuser device 10 can be used for wastewater treatment, for fermentation processes and other methods can be used in which a gas is introduced into a quantity of liquid is to diffuse into it.

Claims (18)

Claims 1. Device for gas diffusion in a liquid, characterized through a channel (20j with at least one small opening (54) in part of it Side wall (46, 48), a device (24, 30, 33, 58) for generating a gas flow through the small opening into the canal to release a small gas bubble (22) to form at the opening (54) and a device (32, 49) for generating a Fluid flow through the channel (20) to the bladder from the opening (54) shear off. 2. Apparatus according to claim 1, characterized in that the opening (54) is one of a series of similar openings in part of the channel (20) and that the device for generating a gas flow through the opening is a gas flow effected through each opening and having a number of capillary tubes (58) of each of which opens into the channel (20) via a corresponding opening (54). 3. Apparatus according to claim 2, characterized by a further Number of capillary tubes (58), which have another row of small openings (54) along a second part of the channel opposite to one part of the channel is, open into the channel (20), so that gas bubbles (22) along the opposite Parts (46, 48) of the channel (20) are formed and sheared off from these when the liquid flows through the channel. 4. Apparatus according to claim 2 or 3, d a d u r c h g e k e n n z e i c h e t that the capillary tubes (58) have essentially straight longitudinal axes have, which run transversely to the direction of flow of the liquid through the channel (20). 5. Device according to one of claims 2 to 4, characterized by a wall (66) which at least partially delimits the channel (20), the capillary tubes (58) are arranged in the wall (66). 6. Device according to one of claims 2 to 5, d a d u r c h g e it is not indicated that the device (32, 49) for generating the liquid flow forms a flow of liquid through the channel (20) at a velocity which is greater than the speed of the gas flow through the capillary tubes (58), so that each bubble (22) has time to move through the flow of liquid from one of the small Offauagen (54) to be carried away before another blister attaches itself to it small opening forms 7. Device according to one or more of the preceding Claims, g e k e n n z e i c h n e t d u r c h a housing (28) which has an elongated Outlet opening (20) limited, a device (32, 49? For generating a liquid flow through the elongated outlet opening (20). through it in a direction perpendicular to its longitudinal axis,, a device, a series of small openings (54) along a longitudinal side Part (46, 48) of the elongated outlet opening (20) and limited by a device (24, 50, 33, 58) to create a gas flow through the rows of small openings through into the outlet opening (20) to form small bubbles (22) which from the longitudinally extending lateral portion (46, 48) of the elongated outlet opening (20) be sheared off by the liquid flow, which is caused by the elongated Outlet opening flows, thereby the gas diffusion in a quantity of liquid (14) to be favored outside the outlet opening (20). 8. Apparatus according to claim 7, characterized by a plurality of capillary tubes (58), each of which with one of the small openings (54) communicates and limits such a small opening. 9. Apparatus according to claim 7 or 8, characterized in that # that the device for generating the gas flow contains a chamber (60) which is shown in Fluid communication with a gas source means that the capillary tubes (58) are in fluid communication with the chamber (60) stand to take gas from the chamber to the corresponding longitudinally running lateral parts (46, 48) of the elongated outlet opening (20) respectively. 10. The device according to claim 8, g e k e n n z e i c h n e t d u r c h further capillary tubes (58), which with a further row of small openings (54) along a second longitudinally extending lateral part of the elongate Communicate outlet opening (20) and limit these small openings, the Device for generating the gas flow contains means to flow a gas through make the second row of small openings through it so that bubbles are formed, those of the second longitudinally extending lateral part of the elongated The outlet opening is sheared off by the fluid flow that is passed through the elongated outlet opening runs. 11. Device according to one or more of the preceding claims for gas diffusion in a relatively large amount of liquid, g e k e n n z e i c h n e t d u r c h housing means (28) having a number of parallel slots (20) limited a device for generating a liquid flow from the Housing device away through the slots into the amount of liquid a first speed, a device that has a number of small openings (54) bounded along at least one lateral portion of each slot and by a device (58) for generating a gas flow through the small openings into the slots at a second speed, to form a series of small gas bubbles at each small opening, the first speed is greater than the second speed to allow the liquid flow shear off the bubbles in all slits and shear them off from the small openings (54) can be carried away before the next subsequent bubbles adhere to the small Form openings, whereby the gas diffusion in the amount of liquid (14) is favored will. 12. The apparatus of claim 11, d a d u r c h g e k e n n z-e i c h n e t that the device that the numerous small openings (54) along delimiting at least one lateral part of each slot (20), a number of capillary tubes (58), the longitudinal axes of which are transverse to the longitudinal axes of the slots and which communicate with the slots via the openings. 13. The apparatus according to claim 12, characterized in that the Capillary tubes (58) have a generally circular cross-sectional shape and diameter between 0.00025 and 0.00050 inches (0.0064 to 0.0128 mm) such that each at the small openings (54) generated bubble (22) has a diameter which is less than 0.004 in. (0.10 mm). 14. Method of gas diffusion in a relatively large amount of liquid using the device according to claims 1 to 13, d a d u r c h g e it is not noted that the gas enters the liquid through at least one opening is introduced to form a bubble at the opening and that the bubble in front their complete formation by a flow of liquid flowing past the opening is flushed into the amount of liquid. 15. The method according to claim 14, characterized in that the Gas is fed to the opening along a capillary tube. 16. The method according to claim 15, d a d u r c h g e k e n n z e i c That is, the velocity of the gas along the capillary tube is slower as the velocity of the liquid flow passing the opening. 17. Device for gas diffusion in a relatively large amount of liquid as described in connection with Figures 1 to 4 of the drawings. 18. device for gas diffusion in a relatively large amount of liquid as described in connection with Figure 5 of the drawings.