WO1995023939A1

WO1995023939A1 - A valve for aerating sludge and alternatively, tapping sludge by manipulating a branch tube in a pipe line

Info

Publication number: WO1995023939A1
Application number: PCT/AU1995/000106
Authority: WO
Inventors: Razmik Mikaelian; Akira Chiba
Original assignee: Dutek Wastewater Purification Pty. Ltd.
Priority date: 1994-03-04
Filing date: 1995-03-06
Publication date: 1995-09-08
Also published as: AUPM425394A0

Abstract

A valve mechanism includes a first conduit (102), at least one tube device (108) extending within the first conduit, and a second conduit (104) intersecting with the first conduit at a junction (106). The tube device has a free end or jet/nozzle which can be located in a plurality of positions within the first and/or second conduits. For a flow of fluid F in the first conduit (102) past the junction (106), the first and second conduits can be arranged and the free end or nozzle can be manipulated e.g. by rotating or sliding, such that in one position, fluid in the tube device is drawn by Venturi or jet pump effect therefrom into the flow of fluid and, in a second position, such that fluid is caused to flow into the tube device (108).

Description

A valve for aerating sludge and alternatively, tapping sludge by manipulating a branch tube in a pipe line.

TECHNICAL FIELD

The present invention relates to a valve mechanism and apparatus employing such a valve mechanism. The present invention finds application in a large variety of fluid (gas and liquid) transfer applications, including the treatment of wastewater, (eg. oxygenating of sludges) . The invention will be in part described with reference to its use in wastewater treatment, but it is to be appreciated that the invention has much broader applications.

BACKGROUND ART Wastewater containing organic matter is treated by the proliferating of micro-organisms through the same, the micro-organisms decomposing the organic matter in the presence of oxygen. Such treatment is referred to as biological treatment, and an oxygenated sludge containing micro-organisms is referred to as an "activated sludge".

A number of apparatus types have been employed for the purpose of aerating wastewater sludge. Apparatus and techniques employed include: submersible pumps, which pump sludge to an environment (eg. surface of a tank) whereby the sludge is aerated; surface impeller-type aerators which are used to aerate the surface of waste treatment ponds; electrical air blowers for the blowing of air into sludge treatment tanks, etc.

The apparatus employed in the transfer of sludge to and from decomposition and/or sludge activation apparatus is either complex, costly, prone to failure or generally cumbersome. Many pump and impeller types fail or break down in the generally continuous modes of operational use found in waste water treatment, particularly in warm or hot climates.

In general, fluid transfer applications in industry could benefit from simple and better designed apparatus, which can facilitate the performance in a single unit of a number of functions (eg. wastewater treatment functions) and can minimise equipment failure and complexity.

DISCLOSURE OF THE INVENTION In a first aspect, the present invention provides a valve mechanism including: a first conduit means and one or more tube means extending into the first conduit means, the or each tube means having a free end which can be located in one or more positions within the first conduit means; wherein for a flow of fluid in the first conduit means, the or each free end can be adapted and/or positioned such that fluid in the or each tube means is drawn therefrom into the flow of fluid and, alternatively, such that fluid is caused to flow into the or each tube means.

Preferably the valve mechanism further includes a second conduit means, wherein the or each tube means extends within the second conduit means and into the first conduit means. Preferably, the position of the or each free end relative to the junction can be adjusted between a first position at which the fluid in the or each tube means is drawn therefrom into the flow of fluid and in which the fluid flows over and outside a predetermined length of the or each tube means, and a second position at which a portion of the flow of fluid is caused to flow into the or each tube means and in which the flow of fluid either: (a) bypasses the or each tube means and/or flows adjacent to the respective free end thereof; or (b) flows over and outside a shorter length of the or each tube means than in the first position.

In the first position, fluid present in the or each tube means can be caused to be drawn into the first conduit means by the flow of fluid over and outside the or each tube means. Thus, a different type of fluid can be introduced into the existing fluid flow in the first conduit means (eg. atmospheric gases such as air and oxygen can be introduced into an aqueous liquid flow) . This inducement can be entirely due to the existing flow of fluid through the first conduit means.

In the second position fluids at various stages of treatment (eg. such as activated sludge or treated sludge) can be transferred from the valve mechanism by changing various flow characteristics of the same.

The valve mechanism of the present invention can be incorporated with any number of different types of flow apparatus to provide a variety of different types of fluid flow, exchange and transfer options.

When the terms "conduit means" and "tube means" are employed, they are intended to cover respectively various conduits and tubes, pipes, ducts, passages, etc. of varying lengths, cross sectional areas, cross sectional shapes, thicknesses, etc.

The or each tube means can be fixedly or slidably mounted at a predetermined position in the first (or second) conduit means.

Thus, in one arrangement preferably the or each tube means extends from either a wall of the first conduit means or a first end of the second conduit means when present, and the or each tube means is slidably mounted at either the wall or the first end respectively for displacement between the first and second positions. The use of slidably mounted tube means facilitates rapid change of flow path and flow conditions within the valve mechanism with relatively low wear and long life of components.

The or each tube means can be slidably mounted within a sealing means which is adapted to prevent fluid from escaping at the mounting.

Employing a sealing means provides a continuous seal during sliding to prevent loss of fluid from the valve mechanism. Typically the sealing means is selected to be of sufficient strength and resilience such that after the or each tube means is slid to an operational position, it is maintained there by the sealing means.

Preferably when the conduit device includes two or more tube means they are either:

(a) positioned next to each other; or

(b) positioned successively one within the other; and wherein the free end of each of which is independently positionable between and/or at the first and second positions. With this arrangement different flow directions within adjacent tube means can be provided to induce turbulence, mixing, etc in the flow of fluid in the valve mechanism. In arrangement (b) of the second position, a constriction to flow can be placed in the first conduit means downstream of the or each free end to cause, at a given flow rate of fluid, at least a portion of the flow of fluid to flow into the or each tube means. The constriction to flow can be caused by a second valve mechanism, similar to that as set forth above. In this way a series of valve mechanisms can be employed to achieve a wide variety of flow regimes. Alternatively, flow constriction can be achieved through conduit means narrowing, variation in conduit direction, and changes to flow criteria such as pump speed, flow rate, fluid pressure, exit fluid levels etc.

In a second aspect the present invention provides apparatus for displacement and/or mixing of fluid comprising: at least one valve mechanism as set forth above; tank means for storing a fluid to be displaced and/or mixed; and pump means for pumping at least a portion of the fluid in the tank means into the first conduit means of the at least one valve mechanism; wherein at least one first conduit means is arranged for selectively returning at least some of the fluid therein to the tank means as return fluid. Preferably, in a first mode of use of apparatus employing a first valve mechanism only, the free end of the or each tube means is adjusted to be in the first position and the pump means is then activated to pump fluid at a given flow rate into the first conduit means such that fluid present in the or each tube means is drawn into the second conduit means and thence into the tank means with the return fluid. Thus, using the valve mechanism as disclosed above in the present apparatus, fluids can be introduced via the valve mechanism (eg. gases such as air, oxygen, liquids etc.) and into the tank means to facilitate whatever treatment or reaction process is taking place in the tank means. In this regard, it should be appreciated that whilst the invention in part is being described with reference to its treatment of wastewater sludges, it could be applied to and used in any other environment where the mixture of fluids is required (eg. in applied chemical reactions, liquid-liquid processes (eg. separation), liquid-gas applications etc.)

Preferably a second mode of use of the apparatus of the invention comprises adjusting the free end of the or each tube means to the second position and then activating the pump means to pump fluid at a given flow rate into the first conduit means to cause at least a portion of the fluid to be transferred into the or each tube means, with the remainder being returned to the tank means as return fluid. Thus, fluid can be removed from the tank means, e.g treated fluid or reacted fluid etc.

The apparatus can employ a second valve mechanism as set forth above, itself operable in both the first and second modes of use. Further valve mechanisms as set forth above can additionally be employed in series with the apparatus and thus a wide variety of flow criteria can be achieved with the valve mechanism and apparatus of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic plan elevation illustrating one embodiment of apparatus according to the present invention;

Figure 2 is a side elevation of the apparatus of Figure 1 taken along the line A - A;

Figures 3 and 4 show cross sectional elevations of two different types of preferred valve mechanisms according to the present invention;

Figure 5 is a cross sectional elevation of a portion of the apparatus in Figure 2 (encapsulated in circle E in Figure 2) detailing a combination of two preferred valve mechanisms according to the present invention; and

Figures 6 to 17 show cross sectional elevations of alternative valve mechanisms according to the present invention.

MODE FOR CARRYING OUT THE INVENTION

Referring to Figures 1 and 2, tank means in the form of vessel 10 is provided for holding a feedstock 12 (e.g a sludge, or other liquid or fluid to be treated) . Two valve mechanisms in series in the form of a valve system

14 is provided at the tank means and receives a portion of the feedstock as a fluid via conduit 15 from a pump means in the form of pump 16 (eg. submersible-type) . The level of fluid in the tank is indicated as W.L. Feedstock can also be introduced to vessel 10 from another source via pipe 22, the flow through which can be regulated by regulating valve 24. The same pipe can also be used to pump fluid from the vessel (as will be explained herebelow) . Fluid can be pumped from the vessel through auxiliary line 26, this line having a control valve 28, the opening of which enables at least a portion of fluid flowing through the valve system to be removed from the vessel 10.

As conduit 15 approaches the valve system 14, it divides into two conduits, namely conduits 30 and 32.

Conduit 30 re-enters the vessel, and the flow through conduit 30 is controlled by control valve 34. Conduit 30 terminates at outlets or diffusers 35 which re-introduce feedstock to the vessel that has previously circulated through the pump 16, conduit 15 and conduit 30 (eg. for the purpose of introducing turbulence to the feedstock) . The amount of feedstock that passes through conduit 32 is regulated by control valve 36 prior to entering the valve system 14.

The valve system 14 includes a first tube means in the form of pipe 38 which slidably extends into a second conduit means and a first conduit means in the form of part of conduit 32 (as herebelow explained in Figure 5) . Pipe 38 includes a valve means in the form of a flow regulating control valve 40 for regulating fluid flow thereinto and thereout. Furthermore a second tube means in the form of pipe 22 slidably extends into a continuation of conduit 32 (as herebelow explained in Figure 5) . Conduit 32 then divides into two further conduits, namely, line 26 (being primarily an exit line from the valve system) and conduit 42. Flow into conduit 42 is regulated by control valve 44, and conduit 42 subsequently terminates in the vessel at diffuser or outlet 46. Thus, there are two major flow loops in the valve system, namely first flow loop 16, 15, 30, 35 (eg. a turbulence loop) and second flow loop 16, 15, 32, 42, 46 (eg. an aeration loop) . As will be appreciated, a large variety of flow regimes can be effected to feedstock and/or other fluid flowing through the valve system by the opening and closing of the various regulating and control valves, by varying pump speed, feedstock and fluid pressure, line pressure, piping direction, tank fluid level etc. A more detailed explanation of how various flow control regimes can be achieved is provided below with reference to the description of Figure 5 (relating to the valve system within the sectional view bounded by circle E) and with reference to figures 4 to 15.

Figures 3 and 4 show schematically two preferred and alternative valve mechanisms. In Figure 3, a valve mechanism in the form of valve 100 has a first conduit means in the form of bent pipe 102. A second conduit means in the form of pipe extension 104 intersects with the bent pipe 102 at a junction shown by the imaginary dotted line 106. Tube means in the form of tube 108 is slidably mounted to pipe extension 104 at a sealing means in the form of seal-bearing 110. Alternatively, the tube 108 can be fixedly mounted to pipe extension 104 to provide a permanent (or fixed) flow profile through valve 100. This latter arrangement may be used when a fixed setting of known performance is required by the end user of valve 100.

A free end in the form of remote open end 112 of tube 108 has a bevelled face formed thereat. The position of the open end 112 within bent pipe 102 and pipe extension 104 can be varied by sliding tube 108 within its seal-bearing 110. Alternatively, the position of the free end may be varied by employing an extendible/contractible tube 108 (eg. having telescopically arranged sections) which can be adjusted to adjust the free end position. Also, when a bevelled (or different type of end face other than square) is employed at the free end, a changing of flow characteristics in tube 108 in certain positions can be achieved by rotating the tube about its longitudinal axis (see arrows R) .

Such sliding and rotational movements can be manually or automatically regulated, and can be computer or electronically controlled to suit the particular flow regimes in which valve 100 is employed. In addition, tube 108 is fitted with a flow control valve 114 which can be completely or partially closed or opened as appropriate.

Throughout this description and in the drawings, the following flow designations will be employed. "I" will be used to designate incoming flow through tubes such as tube 108. "0" will be used to denote outgoing flow through tubes such as tube 108; "F" will be used to designate incoming flow to pipes such as bent pipe 102; and "E" will be used to designate outgoing or exiting flow from pipes such as bent pipe 102.

In Figure 3, bent pipe 102 has an upstream section 116 with respect to fluid entering valve 100 and a downstream section 118 with respect to fluid leaving valve 100. When fluid F is caused to flow into upstream section 116, and tube 108 is in the position shown in Figure 3, the fluid circulates and passes around the outside of tube 108, flowing past the end 112 and into downstream section 118 exiting the valve 100 at E. Because of the positioning of open end 112 in the downstream section 118 of bent pipe 102, and the flow of fluid over and outside a length of tube 108, a suction or negative pressure is induced in the vicinity of the open end 112 and thus any fluid (eg. gas) in tube 108 is introduced into and mixes with fluid in the downstream section 118, exiting at E. (However, if flow control valve 114 is closed, then this phenomenon does not occur.) Figure 4 shows a similar configuration of valve 100 to that as shown in Figure 3, but the remote open end 112' has a square rather than bevelled end face. As indicated above, by changing the shape of the open end, different flow criteria with respect to the inducement of fluid flow from tube 108 result and thus the positioning of the tube end in the valve in order to induce flow is changed.

In Figure 4, the open end 112' has been re- positioned (ie. by sliding tube 108 up in the drawing configuration) so that it lies substantially within pipe extension 104 (ie. behind junction 106) . In this position fluid F in the bent pipe 102 does not flow outside and over pipe 108, but rather flows adjacent to the end 112' . The fluid F thus tends to induce a positive pressure at the open end 112'. This results in an outgoing flow of fluid indicated by arrow 0 in tube 108 (and assuming that flow control valve 114 is opened) . Thus, a portion of the fluid F leaves the valve 100 via tube 108, with the remainder of the fluid exiting the valve from downstream section 118 at E.

Now referring to Figure 5, it will be seen how the valve system 14 is a combination of two preferred valve mechanisms in series. (The valve system 14 defines the generally looped upper portion of conduit 32. ) Figures 6 and 7 show two variations of this combination of valve mechanisms. It should be noted that any number of configurations are possible within the broader context of the flow criteria described herein.

In Figures 5 to 7, the loop section has distinct sections, namely, first angle section 50, straight section 52 and second angle section 54.

In each of Figures 5 through 7, a first valve mechanism has a first conduit means in the form of first angle section 50 and straight section 52, a second conduit means in the form of extension portion 56, and a tube means in the form of pipe 38.

A second valve mechanism in Figures 5 to 7 includes a first conduit means in the form of second angle section 54 and conduit continuation 32', a second conduit means in the form of second extension portion 62 and a tube means in the form of pipe 22.

First angle section 50 intersects with straight section 52 at first inlet 55, and straight section 52 intersects with second angle section 54 at second inlet 61. Fluid F (eg. feedstock 12) flowing in the looped portion of conduit 32 essentially changes direction five times providing useful back-pressure effects. The extension portion 56 extends outwardly from straight section 52 and has a sealing means in the form of a flexible ring or disc seal 58 arranged therein. Pipe 38 is typically mounted for sliding within ring or disc seal 58 in forward and reverse directions, (indicated by arrow R in Figure 5) . The seal can be formed of any suitable material (eg polymeric or natural rubber) and is preferably of sufficient resilience to maintain pipe 38 (and pipe 22) in each of its positions at the operational pressures and flow rates of the apparatus. Alternatively, (as indicated above), the seal can be an end into which pipe 38 is fastened, fixed etc. (eg. by welding, friction fit, adhesive, etc.). The end 60 of pipe 38 has a bevelled face formed thereon. This enhances both fluid inducement (ie. suction) and release from pipe 38 into second angle section 54. However, because of the unique configuration of the apparatus, progressive rotation of pipe 38 about its longitudinal axis from the position shown in Figures 5 and 6 may progressively decrease the flow I of fluid therein, until in some circumstances fluid actually flows out of pipe 38, 38' (ie. in direction 0) .

The second extension portion 62 extends outwardly from the conduit 32' and has a flexible ring or disc seal 64 arranged therein. In a similar manner as above, pipe 22 is typically slidably mounted in the seal 64 for sliding therein in forward and rearward directions (ie. see pipe 22 forward position in Figures 6 and 7) . It should be appreciated that the valve system can comprise a plurality of such pipe sliding mechanisms arranged in series depending on the particular application in which the valve system is employed. For the apparatus of Figures 1 and 2, the double pipe sliding, double valve mechanism configuration has been advantageously employed.

Figure 6 shows a modified version of Figure 5 in which conduit 32" enters above straight section 52' (ie. the valve system is not loop-shaped) . However, a similar piping arrangement as for Figure 5 is employed with pipe 38'. In Figure 6, pipe 22 is shown extended forwardly, such that the remote end 66 extends beyond second inlet 61 (a similar view is shown in Figure 7) . In Figure 7, the end 60 of pipe 38 is shown withdrawn beyond the intersection of straight section 52 and second angle section 54 (ie. as indicated by dotted line 70) .

Figure 8 shows an alternative valve system to that of Figures 5 to 7 in which conduit 32 is curved throughout the valve system. In Figure 8, first, straight and second sections 50, 52 and 54 , are replaced by corresponding sections of this curve, namely, 50", 52" and 54" respectively. In Figure 8, pipe 22 is shown in a withdrawn position with the remote end 66 substantially out of the flow path of feedstock and the end 60 of pipe 38 is shown in an extended position, (the significance of this is explained below) . The operation of the valve system in Figure 8 is substantially the same as for the system shown in Figures 5 to 7.

Referring back to Figure 5 the operation of the valve system will now be explained. Pipe 38 is positioned such that end 60 extends beyond dotted line

(or junction) 70. When feedstock 12 is pumped into the valve system, it is caused to flow by first angle section 50 and straight section 52 in a direction generally towards pipe end 60, and in an annular flow path, (being the space between the internal surface of straight section 52 and the external surface of pipe 38) . As the flowing feedstock passes the end of pipe 38, it induces a suction or negative pressure in the vicinity of the pipe end, and thus in pipe 38, causing a fluid 72 to be drawn into the tube 38 (as indicated) and thence into the general flow of feedstock 12. The fluid 72 could be any desired type of fluid (eg. air or oxygen for wastewater treatment, such as aerobic decomposition) , or a feedstock from a different source, or from the vessel 10 itself (especially where turbulence is required in the fluid) . Alternatively, it could be another liquid (eg. a catalyst for a reaction, or a reaction component etc) .

In Figure 5, pipe 22 is withdrawn such that remote end 66 is behind second inlet 61. At normal wastewater submersible pump pressures and flow rates, as feedstock flows under pressure into second angle section 54 and thence on into conduit 32', fluid tends to be forced into the region adjacent the remote end 66 of pipe 22 causing a positive pressure thereat. Thus a stream 74 of feedstock flows out of pipe 22, with the remainder of the feedstock continuing on in conduit 32' . In some configurations, for a fixed or given position of the end of the pipe 38 (or sliding tube) , at a first low flow rate fluid may flow into or be drawn out of the pipe, whilst at a second relatively higher flow rate fluid may flow in a respective opposite direction. Thus fluid flow rate and/or pressure variation may, in some circumstances be used to change flow directions in the apparatus.

It should be appreciated that flow in pipe 38 and pipe 22 can be controlled respectively by control valve 40 and regulating valve 24 to reduce, increase or stop flow altogether in the pipes respectively. As indicated above, flow regimes can also be varied by varying pump and line pressure, fluid flow rates and tank fluid level Referring to Figures 6 and 7, it will be seen that pipe 22 is advanced such that it extends past inlet 61. In this position, the feedstock 12 under pressure passes through the annular space between the interior surface of conduit 32' and the exterior surface of pipe 22 and tends to induce a suction or negative pressure at the remote end 66 of pipe 22. Thus, fluid 76 is drawn into the flowing feedstock 12 and continues on in the conduit 32 ' . Fluid 76 can be a second (optionally different) fluid such as feedstock, a gas such as air, oxygen, nitrogen etc, or any other type of reacting or non-reacting fluid media (eg. particulate flowable solid material in a gas) desired to be introduced.

In Figure 7, it will be seen that pipe 38 has been withdrawn such that end 60 (in Figure 7 now shown as a straight edge) lies wholly within straight section 52. At a predetermined inlet pressure, feedstock 12 under back pressure tends to slow down somewhat relatively as it enters second angle section 54 and conduit 32 ' with its associated valve arrangement. This is in part due to the change in direction of the feedstock, but can also be due to flow restrictions induced in conduit 32' (such as the second valve mechanism, pipe 22, conduit narrowing, baffling, pump and line pressure variation, flow rate variation, tank level control etc) .

At a predetermined withdrawn position of pipe 38 a positive pressure occurs at end 60 and thus feedstock tends to flow into pipe 38 exiting as stream 80. The predetermined position of end 60 would move closer to seal 58 with increases in feedstock flow rates, line and pump pressures etc. Stream 80 could be a feedstock off¬ take or could be fed back into the vessel 10 (especially when turbulence is being introduced to the feedstock. Alternatively stream 80 can be passed on to further treatment processes.

Similar principles also apply to Figure 8, however a smoother flow transition through conduit 32 occurs because the conduit is continuously curved through the valve system.

Referring to Figure 9 two further embodiments of a valve mechanism in the form of valve 120 are shown. Where relevant, like reference numerals to those employed in Figures 3 and 4 are used to denote similar or like parts. Valve 120 includes a first conduit means in the form of straight pipe 122. A second conduit means in the form of pipe extension 104 intersects straight pipe 122 at junction 106 (shown as an imaginary dotted line) .

In Figure 9, tube 108 includes a bent open end portion 124, which when positioned as shown in Figure 9 results in a fluid flow inducement in pipe 108 as indicated at I. Pipe 108 can be slidingly withdrawn into pipe extension 104 to reverse the direction of fluid flow therein, or alternatively can be rotated so that the angle open end 124 faces incoming fluid F so that a portion of this fluid may pass out of pipe 108.

In Figure 10, pipe 108 is shown with a conventional open end 126 which has been substantially withdrawn into pipe extension 104 to cause fluid to exit valve 120 as stream 0.

Referring to Figures 11 and 12, further variations of valve 100 are now shown. In Figure 11, first and second tube means in the form of small tube 130 and large tube 132 are shown. The small tube 130 is concentrically aligned within large tube 132 and is independently slidable therewithin. Similarly, the large tube 132 is independently slidable within seal-bearing 110. Small tube 130 has a respective flow control valve 134 associated therewith, whereas large tube 132 has a respective flow control valve 136 associated therewith. The flow control valve 136 can also function as a seal- bearing to small tube 132 to maintain its concentric alignment within the large tube and also to prevent fluid escaping from the valve 100 in the annular space between the small and large tubes.

As can be seen in Figure 11, the end 138 of the large tube 132 is substantially withdrawn into pipe extension 104, whereas the end of the small tube 130 is positioned well into bent pipe 102. Thus, for fluid F flowing in bent pipe 102, a positive pressure is induced at large tube end 138 causing fluid to flow out through this tube (indicated by 0) , whereas fluid flows over and outside small tube 130, inducing a fluid inflow in this tube (indicated by I) to mix with fluid in downstream section 118.

In Figure 12, a similar configuration in principal to that of Figure 11 is shown. Two tube means in the form of adjacent tubes 140, 142 are shown. The tubes have respective flow control valves 144, 146 associated therewith, and each tube can be independently slidingly displaced within seal-bearing 110. In this regard, it can be seen that remote open end 148 of tube 140 is withdrawn into pipe extension 104, whereas remote open end 150 of tube 142 is positioned well into bent pipe 102. Thus, an outgoing flow of fluid F occurs in pipe 140 (indicated by 0) whereas an induced inflow through pipe 142 (indicated by arrow I) occurs in pipe 142. Referring to Figure 13, there is shown a valve mechanism in the form of valve 155, which has a first conduit means in the form of curved pipe 160 and bent pipe section 162. Tube 108 has a bevelled open end 164, the bevel being cut such that fluid leaving tube 108 travels substantially in the same direction as fluid in downstream section 118.

In the position of tube 108 in Figure 13, fluid F flows over and outside a substantial portion of tube 108, thus inducing (or drawing) any fluid therein and into the stream of fluid E exiting the valve.

Referring to Figures 14 and 15, two variations on the configuration of Figure 13 are shown. In effect, two separate valves 155 and 165 are arranged in series, with the first conduit means of the first valve continuing as the first conduit means of the second valve. (These valves could also be used with the apparatus of Figures 1 and 2) . In Figure 14, a second pipe extension 104' is provided and intersects with bent pipe section 162 at junction 106'. The second pipe extension includes a similar configuration to the first pipe extension, including tube 108' slidingly mounted in seal-bearing 110'. Tube 108' is shown such that its remote bevelled end is withdrawn into pipe extension 104' so that fluid flowing through curved pipe 160 and bent pipe section 162 causes a positive pressure at the end resulting in an outflow of fluid 0 in pipe 108'. On the other hand, pipe 108 of the first pipe extension 104 is in the same position as in Figure 13 and thus fluid is drawn therefrom by the general flow of fluid F through the valve 155 and thence valve 165.

Figure 15 shows a substantially similar arrangement to that of Figure 14, however, the end of tube 108' has been advanced into bent pipe section 162 so that fluid is drawn from both pipes 108, 108' into the general fluid stream F to mix and exit at E. Tubes 108 and 108' can each be mounted in their seal-bearings 110, 110' such that when the tubes are advanced, the ends of each tube thereof do not engage, bump or interact. However, the open ends of each tube can be positioned adjacent to each other, and this can be particularly advantageous when mixing two fluid streams for example, or when, imparting turbulence etc. to the flow of fluid.

Referring to Figures 16 and 17, modified valve mechanisms 100' each include a first conduit means only, in the form of bent pipe 102 and straight pipe 102' respectively. Neither of the valves employ a second conduit means and, in both cases, tubes 108,108' are either slidably or fixedly mounted to bent pipe/straight pipe 102,102' via a wall mounting/seal 110. When the tubes 108,108' are fixedly mounted at 110, for both the configurations shown in Figures 16 and 17, a flow of fluid I will be induced in both tubes, mixing with fluid F in downstream section 118 and exiting at E. In Figure 16, however, tube 108 could be withdrawn (ie. slid upwardly in the drawing) so that its free end 112 is substantially aligned with seal 110. In such a position, a portion of the fluid F may be caused to flow out of the valve via tube 108.

Any of the free ends of the various tube means can be altered and configured as suitable. For example, the free ends can be provided with a plurality of perforations adjacent thereto to improve fluid release from the tube. The perforations can be in the form of one or more laser angle cuts formed in the tube. As indicated above, slanted or bevelled cuts can be formed at the free end and circular or other type cuts may also be employed where appropriate.

The first and second conduit means may take many forms and configurations and may be straight, bent or curved, or formed from a plurality of different types of straight, bent and curved sections depending on the application in which the valve mechanisms are employed.

For example the valve mechanism can be employed in a tubular-type reactor vessel, in which a reaction commences at intake into the reactor and proceeds to various stages whilst flowing through the reactor and then is completed when exiting the reactor. The various valve arrangements can be used to either add different reactants at different stages or to extract various components or fractions at different stages.

Many different types of flow configurations can be achieved by employing the fixed and sliding pipe-conduit and valve configurations described above. Apparatus described herein can be used in the treatment of wastewater for the introduction of air into feedstock, the introduction of feedstock into the vessel, the transfer of feedstock from the vessel, the transfer of sludge (ie. that has accumulated on the base of the vessel) etc.. The valve configurations can be used in chemical reactors for the mixing of fluids or in any other industrial situation where it is required to bleed or remove part or all of a stream, or to mix two or more fluid streams together, or to introduce turbulence to fluid streams etc..

The various valve configurations provide a structurally and mechanically sound way of ensuring proper direction of the travel of one or more fluid streams, as optimum positioning of the fixed and/or sliding' pipe-conduit arrangement can be determined and this can be very easily reproduced and re-established after, for example, a position change of the apparatus for different flow regimes. In the treatment of wastewater, the apparatus described above provides a very effective way of transferring fluids from process to process and introducing fluids into the process, without the use of existing complex, cumbersome or expensive devices. Thus, there is little or no need for air blowers, expensive pumping apparatus, surface impellers, complex or costly transfer pumps etc when apparatus as described is employed.

Whilst the invention has been described with reference to a number of preferred embodiments it should appreciated that the invention can be embodied in many other forms.

Claims

1. A valve mechanism including: a first conduit means and one or more tube means extending into the first conduit means, the or each tube means having a free end which can be located in one or more positions within the first conduit means; wherein for a flow of fluid in the first conduit means, the or each free end can be adapted and/or positioned such that fluid in the or each tube means is drawn therefrom into the flow of fluid and, alternatively, such that fluid is caused to flow into the or each tube means.

2. A valve mechanism as claimed in claim 1, further including a second conduit means, wherein the or each tube means extends within the second conduit means and into the first conduit means.

3. A valve mechanism as claimed in claim 1 or claim 2, wherein the position of the or each free end can be adjusted between a first position at which the fluid in the or each tube means is drawn therefrom into the flow of flui^'d and in which the fluid flows over and outside a predetermined length of the or each tube means, and a second position at which a portion of the flow of fluid is caused to flow into the or each tube means and in which the flow of fluid either:

(a) bypasses the or each tube means and/or flows adjacent to the respective free end thereof; or

(b) flows over and outside a shorter length of the or each tube means than in the first position.

4. A valve mechanism as claimed in claim 3, wherein the or each tube means extends from either a wall of the first conduit means or a first end of the second conduit means when present, and the or each tube means is slidably mounted at either the wall or the first end respectively for displacement between the first and second positions.

5. A valve mechanism as claimed in claim 4, wherein the or each tube means is slidably mounted at the wall or the first end respectively within a sealing means which is adapted to prevent fluid from escaping at the mounting.

6. A valve mechanism as claimed in any one of claims 3 to 5 that includes two or more tube means that are either:

(a) positioned next to each other; or

(b) positioned successively one within the other; and wherein the free end of each of which is independently positionable between and/or at the first and second positions.

7. A valve mechanism as claimed in any one of claims 3 to 5, wherein in arrangement (b) of the second position a constriction to flow is placed in the first conduit means downstream of the position of the or each free end to cause, at a given flow rate of fluid, at least a portion of the flow of fluid to flow into the or each tube means.

8. A valve mechanism as claimed in claim 7, wherein the constriction to flow is caused by a second valve mechanism of the same arrangement as that defined in any one of claims 1 to 6, wherein in use, the first conduit means of the first valve mechanism joins the first conduit means of the second valve mechanism such that any fluid not flowing out of the first valve mechanism via the or each tube means flows into the second valve mechanism.

9. A valve mechanism as claimed in claim 7, wherein the constriction to flow is caused by bending, narrowing or arranging a flow impediment in the first conduit means downstream of the or each free end.

10. A valve mechanism as claimed in claim 1 or claim 2, wherein the or each tube means is fixedly mounted at a wall of the first conduit means, or is fixedly mounted at a first end of the second conduit means when present.

11. A valve mechanism as claimed in any one of the preceding claims, wherein said adaptation of the or each free end can include: (i) a straight cut; (ii) a bevel cut; (iii) a bend in the or each tube means; and/or (iv) one or more perforations adjacent to the free end.

12. A valve mechanism as claimed in any one of the preceding claims, wherein the or each tube means has a longitudinal axis around which the or each tube means can be rotated.

13. A valve mechanism as claimed in claim 2, wherein the first conduit means intersects the second conduit means at a junction such that an acute angle is subtended between the second conduit means and that portion of the first conduit means that in use is upstream of the junction.

14. A valve mechanism as claimed in claim 13, wherein the acute angle is approximately 45°.

15. A valve mechanism as claimed in claim 2, wherein the first and second conduit means and the or each tube means are tubular members.

16. A valve mechanism as claimed in claim 15, wherein the or each tube means is generally concentrically disposed within the second conduit means.

17. A valve mechanism as claimed in any one of the preceding claims wherein the first conduit means is:

(a) straight; (b) curved;

(c) comprised of distinct straight and/or curved portions.

18. A valve mechanism as claimed in any one of the preceding claims, wherein the or each tube means has a respective valve means located externally to the valve mechanism for regulating the flow of any fluid in the or each tube means.

19. Apparatus for displacement and/or mixing of fluid comprising: at least one valve mechanism as defined in any one of the preceding claims; tank means for storing a fluid to be displaced and/or mixed; and pump means for pumping at least a portion of the fluid in the tank means into the first conduit means of the at least one valve mechanism; wherein at least one first conduit means is arranged for selectively returning at least some of the fluid therein to the tank means as return fluid.

20. Apparatus as claimed in claim 19 having a first valve mechanism only, wherein in a first mode of use, the free end of the or each tube means is adjusted to be in the first position and the pump means is then activated to pump fluid at a given flow rate into the first conduit means such that fluid present in the or each tube means is drawn into the first conduit means and thence into the tank means with the return fluid.

21. Apparatus as claimed in claim 20, wherein a second mode of use comprises adjusting the free end of the or each tube means to the second position and then activating the pump means to pump fluid at a given flow rate into the first conduit means to cause at least a portion of the fluid to be transferred into the or each tube means, with the remainder being returned to the tank means as return fluid.

22. Apparatus as claimed in claim 20 or claim 21, including a second valve mechanism as set forth in claim 8, the second valve mechanism being as defined in any one of claims 1 to 18, wherein: when the first valve mechanism is in the first mode of use, the fluid which would otherwise be returned to the tank means is directed into the upstream portion of the first conduit means of the second valve mechanism; and when the first valve mechanism is in the second mode of use, that portion of the fluid not being pumped into the or each tube means and which would otherwise be returned to the tank means is directed into the upstream portion of the first conduit means of the second valve mechanism; and wherein the downstream portion of the first conduit means of the second valve mechanism is arranged in either mode of use to selectively return any fluid therein to the tank means as return fluid.

23. Apparatus as claimed in claim 22, wherein the second valve mechanism has first and second modes of use as defined in any one of claims 20 to 22.

24. Apparatus as claimed in claim 23, including one or more further valve mechanisms, the or each further valve mechanism being as defined in any one of claims 1 to 16 and the or each further valve mechanism being arranged in flow series with a preceding valve mechanism, such that in use, the downstream portion of the first conduit means of the preceding valve mechanism is in fluid communication with the upstream portion of the first conduit means of that valve mechanism, and wherein the downstream portion of the first conduit means of the final valve mechanism in the series is arranged for selectively returning any fluid therein to the tank means, and with the or each of the further valve mechanisms having first and second modes of use as defined in any one of claims 20 to 23 respectively.

25. Apparatus as claimed in any one of claims 20 to 24, wherein ^'the tank and pump means are adapted for pumping fluid in the form of a liquid, and wherein the or each tube means is adapted for transporting fluid in the form of a gas in the first mode of use and in the form of a liquid in the second mode of use.

26. Apparatus as claimed in claim 25, wherein in use the liquid is a sludge fed to the tank means for aeration, and the gas is air or oxygen, such that with at least one of the or each valve mechanisms in the first mode of use, the sludge is aerated, whilst with at least one of the or each valve mechanisms in the second mode of use, at least a portion of the sludge is pumped out of the tank means and/or is recirculated back into the tank means.