GB2394910A

GB2394910A - Static tubular aerator with freely rotating turbines or paddles

Info

Publication number: GB2394910A
Application number: GB0225968A
Authority: GB
Inventors: John Sydney Franklin
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-11-07
Filing date: 2002-11-07
Publication date: 2004-05-12
Also published as: GB0225968D0

Abstract

A static tubular aerator is fitted with groups of turbines or fan like paddles 4a-d with bearings and peripheral shells attached to the turbines/paddles. The turbines/paddles which can be mounted on supports 5, 5a can freely rotate under the action of a rising column of air or gas which comes from perforated gas pipe 3 in water or other liquid which enters via opening 6a-d. The aerator is housed in a vertical free standing submerged tube 1 and converts large bubbles of low pressure air or gas into fine ones through the rotating action of the turbines/paddles for aeration or treatment of water or other liquids. The shells on the turbines may be vertical (Figs 1-2) and hence parallel with housing 1 or slanted (Figs 3-4).

Description

23949 1 0

STATIC TUBULAR AERATOR

The aeration of liquids is a well known process and is used for many purposes. Air, or a gas, is introduced into a body of water or a fluid in a number of different ways including, for example, simple sparge pipes producing large bubbles using low pressure air, a variety of fine bubble devices using high pressure air, surface aerators using powerful motors to rotate either horizontally or vertically disposed machinery and tubular aerators some of which use coarse bubbles and need heavy sub- surface foundations. An attempt was made in America to combine the advantages of coarse bubble aeration with the efficiency of fine bubbles using a tubular device with low pressure air fed into a vertical tube in which there are turbines or paddles free to rotate on individual supports under the influence of a rising column of air and water created in the tube by the well known "air lift" principle. The turbines did not have bearings l or protection against blockage by suspended solids and had large clearance spaces all round them. Later an attempt was made to overcome the blockage problem by locating the turbines in a tube within the the outer tube but there was no provision for liquid to enter the inner tube so that the twbines did not revolve with sufficient speed to produce adequate small bubbles making the process little better than a simple sparge pipe.

The present invention utilises freely rotating turbines or paddles with radial blades at an angle to the axis, each turbine having a peripheral wall or shell and appropriate bearings, mounted in a group or groups within a vertical tube equipped with a simple base enabling the wit to be free standing in a body of water or other liquid. The integral shells of the twbines may be parallel or inclined at an appropriate angle to the to the turbine axis so as to control and direct the flow of air, or other gas, bubbles and water, or other liquid, within the tubular housing. The bearings ensure free rotation without vibration of the twbines enabling them to be set close together which in combination with the mounting arrangements gives a good shearing action and produces many fine air, or gas, bubbles from coarse ones introduced into the Unit at low pressure through a perforated pipe located below the twbines. Water, or other liquid, enters the housing through appropriately configured apertures in the housing wall and an upward flow of water, or other liquid, is created by the density change within the unit causing the turbines to rotate. Thorough mixing within the unit and in the rising turbulent stream of air and water encourages good oxygen transfer fwther enhanced by the surface boil effect above the unit. Appropriately configured the wit can safely handle suspended or semi-bouyant solids such as hairs, leaves, pieces of plastic and the like.

An embodiment by way of example only of the equipment according to the present invention will now be described with reference to the accompanying drawings numbers, 1, 2, 3 and 4 in which, Drawing Number 1 shows the tubular housing 1, with simple base 2 and perforated air inlet pipe 3, with two groups of turbines with shells parallel to the axis 4a, mounted one above and one below the support ring 5 and vertical oval liquid inlets 6a in the tubular housing.

Drawing Number 2 shows the tubular housing 1, with simple base 2, perforated air inlet pipe 3, and two groups of turbines with shells parallel to the axis 4b mounted in pairs above the supports 5 and circular liquid inlets 6b in the tubular housing Drawing Number 3 shows the tubular housing 1, with simple base 2, perforated air inlet pipe 3 and a single group of turbines 4c with angled shells having a larger diameter at the bottom than the top mounted on a common support S and horizontally disposed oval liquid inlets 6c in the tubular housing.

Drawing Number 4 shows a larger tubular housing la with simple base 2a, perforated air inlet pipe 3a and a single group of turbines with angled outer shells having a larger diameter at the top than the bottom and extended upwards beyond the bottom of the turbine above 4d all mounted on a single support Sa and with vertical slot type liquid inlets 6d in the tubular housing.

The units shown on all the drawings numbers 1, 2, 3 and 4 are designed to use low pressure air, or a gas, for treatment of liquids, for example aeration of water, in ponds, tanks, lagoons or any other containment. The units are designed to be free standing on an integral base obviating the need for under water work or foundations.

Air, or a gas, at low pressure just in excess of that required to overcome static head and pipe line losses is admitted into the static tubular unit by a perforated pipe 3 or other suitable means.

Above the air (gas) inlet pipe there are mounted freely rotating turbines arranged so that each rotates in the opposite direction to the adjacent one. The turbines have angled radial blades with sharp edges so that air (or gas) bubbles passing upwards in the water (liquid) stream are sheared into smaller ones at each interface of the turbines and/or the venturi type supports, 5 and 5a.

Referring to Drawings I. 2. 3 and 4 the outer shell I and 1 a is a single vertically orientated tube equipped with a simple base 2 and 2a, that can be of concrete by way of example only, securely attached to the main tube. making a free standing unit that can be installed into a pond or other body of water or liquid from the surface without the need for sub-surface work.

Air, or a gas, is admitted into the tubular shell 1 and la through a perforated pipe 3 and 3a or other device located beneath the turbines 4a, b, c and d. Water, or other liquid, enters the tubular shell 1 and la at an appropriate height through one or more openings 6a, b, c and d of predetermined shape, size and location.

Turbines 4a, b, c and d mounted above the air(gas) inlet pipe in various combinations including pairs, Drawings 1 and 2 or in a single stack, Drawings 3 and 4. The turbines are supported on a venturi type ring with radial arms and a central boss, 5.

Referring to Drawing Number 4 the outer shell is similar to that on Drawings Numbers 1, 2 and 3 being a slightly larger diameter vertically orientated tube la equipped with simple base 2a, air (gas) inlet pipe 3a and fluid openings 6d. The openings may be circular horizontally or vertically extended the latter being the preferred option in this example. Within the outer shell and above the air (gas) inlet pipe are mounted on a single axle three, or more, freely rotating turbine 6d each having an integral outer shell or skirt with the upper edge of larger diameter than the lower and extended upwards in a conical fashion above the top edge of the turbine blades and the lower edge of the turbine above. The turbines are of smaller diameter than the tubular shell to provide a clear annular space 7 between turbine periphery and the inside wall of the tubular shell la. Suspended solids are then able to rise preferentially in the annular space and avoid passing through the turbine allowing clear water (liquid) to rise through the turbines causing them to rotate and shear air (gas) bubbles as required. A clearance space or circular aperture 8, is provided at each turbine interface around the upper peripheral edge so that a proportion of the rising liquid and gas mixture is able to enter and rise in the annular space 7 between turbines and shell wall to effectively create a good rising column of water (liquid) and air (gas) in that area to promote the flotation of suspended solids.

Claims

1. An improved system and method of dispersing a gas into a liquid, in particular but not confined to, the aeration of water for treatment or purification purposes comprising freely rotating turbines or paddles fitted with bearings and having an integral peripheral shell supported and horizontally disposed within a vertical tube fitted with a suitable base and having appropriate openings for liquid access, a perforated gas inlet pipe, the whole unit being submerged and free standing in a body of water.

2 Tubular aerators as claimed in I above to combine the advantages of coarse bubble equipment with the efficiency of fine bubble aeration equipment using only low pressure air or gas for aeration, deaeration, treatment, destratification of Liquids and other purposes.

3 Tubular aerators as claimed above to utilise the natural "air lift" principle to cause adjacent turbines or paddles mounted within a vertical tube to rotate in such a manner as to shear rising gas bubbles into smaller ones

4 Tubular aerators as claimed above whereby contra- rotating turbines or paddles successively produce smaller and smaller bubbles thereby increasing the efficiency of the process.

5 Tubular aerators as claimed above with freely rotating turbines or paddles fitted with appropriate wear and vibration defeating bearings to give prolonged life, smooth and fast rotation for a substantial gas bubble shearing capacity.

6 Tubular aerators as claimed above in which contra- rotating turbines or paddles may be mounted in pairs one above and one below a venturi type support or adjacent to each other between two supports or as a single stack on one spindle.

7 Tubular aerators as claimed above fitted with freely rotating turbines or paddles manufactured with an integral peripheral shell that may be parallel to the axis or at an angle in a conical fashion with the upper diameter being smaller than the lower so as to direct the flow of air and water inwards and overcome any tendency of the angled radial turbine blades to disperse gas. bubbles to the periphery.

\ s 8 Tubular aerators as claimed above fitted with freely rotating turbine or paddles manufactured with an integral peripheral shell of a conical nature such that the upper edge has a diameter greater than the lower and is extended above the angled radial blades and the base of an adjacent turbine mounted above so as to provide a good upward flow of gas and liquid in an annular space around the turbines for the free passage of suspended or semi-bouyant solids 9 A method of effectively dispersing air or a gas in water or a liquid being substantially as hereinbefore described with reference to the accompanying representations. 10 Any feature or novelty, taken singly or in combination of the embodiments of the invention hereinbefore described with reference to the accompanying representations.

Amendments to the claims have been filed as follows 1. An improved tubular aerator system for dispersing a gas into a liquid, in particular but not confined to, the aeration of water for treatment or purification purposes comprising freely rotating turbines or paddles with radial blades at an angle to the axis, each having a peripheral wall or shell and appropriate bearings the turbines being supported and horizontally disposed within a vertical tube fitted with a suitable base and having appropriate openings for liquid access and a perforated gas inlet pipe.

2. Tubular aerators as claimed in 1 above to combine the advantages of coarse bubble equipment with the efficiency of fine bubble aeration equipment using only low pressure air or gas for aeration, deaeration, treatment, destratification of Liquids and other purposes 3..Tubular aerators as claimed above to utilise the natural "air lift" principle to cause adjacent turbines or paddles mounted within a vertical tube to rotate in such a manner as to shear rising gas bubbles into smaller ones 4. Tubular aerators as claimed above whereby contra- rotating turbines or paddles successively produce smaller and smaller bubbles thereby increasing the efficiency of the process.

5. Tubular aerators as claimed above with freely rotating turbines or paddles fitted with appropriate wear and vibration defeating bearings to give prolonged life, smooth and fast rotation for a substantial gas bubble shearing capacity 6. Tubular aerators as claimed above in which contrarotating turbines or paddles may be mounted in pairs one above and one below a venturi type support or adjacent to each other between two supports or as a single stack on one spindle.

7. Tubular aerators as claimed above fitted with freely rotating turbines or paddles manufactured with an integral peripheral shell that may be parallel to the axis or at an angle in a conical fashion with the upper diameter being smaller than the lower so as to direct the flow of air and water inwards and overcome any tendency of the angled radial turbine blades to disperse gas. bubbles to the periphery.

8. Tubular aerators as claimed above fitted with freely rotating turbine or paddles manufactured with an integral peripheral shell of a conical nature such that the upper edge has a diameter greater than the lower and is extended above the angled radial blades and the base of an adjacent turbine mounted above so as to provide a good upward flow of gas and liquid in an annular space around the turbines for the free passage of suspended or semi-bouyant solids i