DEVICE FOR BLOWING A GAS INTO A LIQUID

Abstract: This invention relates to a device for supplying a gas, preferably air, to a liquid intended to be purified by means of a biological treatment. The device is comprising a plurality of distribution tubes (5) which radially like arms are connected to a central rotatable tube (2) which is closed at its upper end. The radially arranged distribution tubes are provided with holes or nozzles (7) directed in the horizontal plane perpen­ dicular to the distribution tubes and the distribution tubes are also connected to floating means which will float on the sur­ face of the liquid treated and keep the distribution tubes at a fixed level underneath the level of the liquid surface. The rotatable tube connected to said distribution tubes is telescop­ ically journalled on a stationary tube 1 which is connected to a source of pressurized gas. When pressurized gas from the stationary tube 1 is supplied to the distribution tubes the gas will escape through said holes or nozzles in the form of fine jets and the gas will be mixed with the liquid at the same time as the action- and reaction forces from the gas jets will give the device a rotating movement.

Description: Device for #loig a gas into a liquid The purpose and main characteristics of the invention: The purpose of the invention is to bring about a device by means of which the supplying and blowing in gas can be carried out under a maximum of surface area, and that the level or the liquid can be permitted to fluctuate from a certain minimum depth to an optional maximum depth in the reservoir without changing the capacity of the gas supply. The problem has been solved by means of the invention which is relating to a device comprising a plurality of distribution tubes radially projecting from a central tube which is rotatable around its longitudinal axis, each of said distribution tubes beeing provided with a plurality of gas outlets. The invention is characterized by that the said gas outlets are arranged to direct a flow of gas in the horizontal plane and that the gas outlets are arranged in such a way that they are cooperating in order to give the device a rotating movement and that the said distribution tubes and/or the central tube are connected to floating means which are arranged to define the position of the said distribution tubes in relation to the surface level of the liquid. An embodyment of the invention will in the following be described with reference to the enclosed schematic drawing in which fig. 1 is showing a part of a cross section through the device and fig. 2 is showing a part of a view seen from above. Description of an embodyont of the invention: In the drawing the inner stationary central tube is designated with 1 and the other moveable arid rotatable tube wlth 2. The other tube 2 is at its lower end provided with a sealing designated by 3. The floating means which are attached to the tube 2 are designated with 4. The distribution tubes designated by 5 are by means of the fasten ing devices 6 attached to the floating means 4. The outlets for the gas in the distribution tubes 5 are designated by 7. Supports inbetween the floating means 4 and trie distribution tubes are designated by a and 9 respectively. Permitted fluctuation for the level of the liquid has been designated by A. As earlier mentioned one or more of the devices in accordance ijith the invention are placed in a reservoir, a tank or a da containing a liquid which is intended to be treated uith gas, for instance air whereby the gas with even distribution is brought into contact it the liquid. From a source of pressurized gas, not shown here, the gas intended for the treatment is conveyed to a stationary tube 2 which tube is supporting and guiding the device. The stationary central tube 1 is carrying a rotatable tube 2 which is closed at its upper end and which is telescopically arranged over the stationary central tube 1. By means of a sealed or tight slide bearing 6 the rotatable central tube 2 is journalled for rotating as well as sliding movement along the stationary tube 1. Owing to the fact that the stationary central tube 1 at its upper end in communicating with the inside of the rotatable central tube 2 this will be filled with the said gas intended for supplying to the liquid. As the said radially arranged distribution tubes 5 are communicating with the rotatable tube 2 the gas will be introduced into the distribution tubes 5 and be pressed out through the gas outlets in the form of holes or nozzles 7 in the distribution tubes 5 which holes are directed for a gas flow mainly in the horizontal plane. As the holes or nozzles 7 are arranged to give the jets of outflowing gas a direction which is perpendicular to the axis of the distribution tubes 5 the outflowing gas will by means of a combined action- and reaction force on the distribution tubes 5 turn the device around the central tube 1. This action on the distribution tubes will of course be amplified if all the holes or nozzles 7 in all the distribution tubes 5 are arranged to cooperate. Due to the force action on the liquid from the outfiowing gas the liquid will be given a rotating movement in opposite direction compared with the movement of distribution tubes 5. This movement of the liquid will promote the admixture of gas and prolonge the time during which the liquid will stay in the reservoir in the case the liquid continously is supplied to and removed from the reservoir. In order to make it possible for the device to function when the level of the liquid in the reservoir is fluctuating and always to work against a constant counterpressure from the liquid the blowing in of the gas has to be performed at a constant depth under the level of the liquid. This is attained by the help of floating means 4 which are connected to the rotatable tube 2 and/or the distribution tubes 5. Said floating means 4 which in order to prevent unbalance ought to be evenly distributed around the rotatable central tube 2 can as shown be arranged parallel with the distribution tubes 5 i.e. radially. The floating neana 4 can however also be arranged tangentially which has the advantage that the resistance against the movement along the surface of the liquid will be decreased (especially in the case the floating moans 4 are given the form of circular segments). A further advantage is that the floating means 4 or more correct parts connected to the floating means 4 can form supports 8, 9 which will mecanically stabilize the distribution tubes 5. The maximally permitted variation of the level for the liquid surface is determined by the length of the stationary central tube 1 and the length of the rotatable tube 2. The liquid volume in the reservoir which is directly treated with gas is determined by the length of the distribution tubes 5. It has been found that an effective gas treatment can be achieved in a cheap, simple and safe way by means of the device in accordance with the invention.

Claims: C L A I r: S 1. Device for supplying and mixing gas, preferrably air, to a liquid, comprising a plurality of distribution tubes (5) radially projecting from a central tube (2) which is rotatable around its longitudinal axis, each of said distribution tubes (5) beeing provided with a plurality of gas outlets (7) characterized in that the said gas outlets (7) are arranged to direct a flow of gas in the horizontal plane and that the gas outlets (7) are arranged in such a way that they are cooperating in order to give the device a rotating movement and that the said distribution tubes (5) and/ or the rotatablfcentral tube (2) are connected to floating means (4) which are arranged to define the position of the said distribution tubes (5) in relation to the surface level of the liquid. 2. Device in accordance with claim 1 characterized in that the outlets (7) of the distribution tubes (5) are directed in tangential direction to the said roating movement given to the device by the means of the dis charging gas. 3. Device in accordance with claim 1 characterized in that the said rotatable tube (2) is telescopically arranged around and radially as well as longitudinally journalled on a fixed central tube (1) which is connec ted to a source of pressurized gas, preferrably air, and that said fixed central tube (1) communicates with the rotatable tube (2) as well as the radial distribu tion tubes (5). 4. Device in accordance with claim 1 characterized in that the distribution tubes (5) as well as the floating means (4) are evenly distributed around the rotatable central tube (2).

Inventors: GUNNARSSON, ROLF
Applicants: PURAC AB
Application year: 1984
Main classification: C02F7
IPC codes: B01F5, C02F7, B01F3, C02F3