GB1561084A - Hydraulic turbines - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO HYDRAULIC TURBINES (71) We, RANKEL TURBINES LIMITED, a British Company of Rockbourne Mews, 56a, Rockbourne Road, Forest Hill, London, S.E.23. do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to hydraulic turbines.

In our British Patent Application No.

1409093 we describe and claim a hydraulic turbine for driving a compressor for refrigeration equipment comprising one or more bladed turbine rotors mounted on a shaft rotatably mounted in a housing, a plurality of nozzles spaced around the or each turbine rotor arranged to direct tangential jets of fluid at the blades of the or each turbine rotor, and means for varying the number of nozzles which are operational.

We have now realised that a hydraulic turbine as described in the aforesaid British Patent Application is suitable for other usages in addition to being suitable for the driving of a compressor for refrigeration equipment. Such a hydraulic turbine could be used, for example, to drive a compressor for equipment other than refrigeration equipment. Its possible usage need not however, be limited to the driving of compressors and in general terms it is suitable for driving rotary equipment at high speeds and as a further example of its possible use it may be used to drive an air fan. It is applicable, inter alia, to equipment for movement of air or other gases, providing suction e.g. for vacuum cleaning and the conveying of solid particulate materials.

According to the invention a rotary gas moving equipment has a rotary gas moving member driven by a hydraulic turbine comprising one or more bladed turbine rotors mounted on a shaft rotatably mounted in a housing, a plurality of nozzles spaced around the or each turbine rotor, arranged to direct tangential jets of hydraulic fluid at the blades of the or each turbine rotor, these nozzles urging the rotor in a common direction, and on-off control means for varying the number of nozzles which are in operation.

Preferably the means for varying the number of nozzles which are operational comprises means for selectively terminating the flow of hydraulic fluid through the nozzles by solenoid operated valves adapted to open and close the nozzles or the feed pipes thereto. The variation of the number of nozzles which are operational enables a variation in the power output of the turbine to be obtained whilst the hydraulic supply pressure remains substantially constant. The selection of the number of nozzles which are operational may be manual or may be made automatically by a mechanism which senses the power input requirements of the equipment driven by the turbine.In the case of a radial flow compressor, for example, which is required to rotate at a substantially constant speed but to have a variable throughput, the variation in throughput may be accompanied by a variation in the attitude of swirl vanes in the axial inlet thereto, and the mechanism which varies the attitude of the swirl vanes can be arranged to act to select the number of nozzles operating which is appropriate to the throughout of the compressor.

Preferably the or each turbine rotor has four or six nozzles spaced therearound.

Where the turbine has a plurality of turbine rotors we prefer to leave a space between rotors which is equal to at least one and a half times the axial width of a rotor.

The hydraulic fluid is preferably supplied to the turbine by an electrically driven gear pump and conveniently the turbine housing is secured to the hydraulic fluid reservoir and has suitably disposed holes in its housing whereby hydraulic fluid may drain by gravity back into the reservoir.

The invention will now be described, by way of example, with reference to the accom panying drawings in which: Figure 1 is a vertical cross-section through the compressor and hydraulic turbine drive unit with a hydraulic turbine according to the invention, Figure 2 is a cross-section along the line A-A of Figure 1, Figure 3 is an axial view of a turbine wheel.

Figure 4 is a cross-section along the line B-B of Figure 3, Figure 5 is a cross-section through a turbine blade along the line C-C of Figure 4, Figure 6 is an axial view of an alternative wheel, Figure 7 is a cross-section along the line D-D of Figure 6, Figure 8 is an axial view of a further alternative turbine wheel, Figure 9 is a radial view of the turbine wheel shown in Figure 8, Figure 10 is a diagrammatic representation of a compressor and hydraulic fluid supply, Figure 11 is a diagrammatic representation of the co-operative operation of a hydraulic turbine nozzle control circuit and variable attitude swirl vanes in the compressor inlet, Figure 12 is a cross-section through the compressor inlet along the line E-E of Figure 11; Figure 13 shows a modification and Figure 14 shows the application of the turbine to a conveying apparatus.

Referring firstly to Figures 1 and 2, the housing of the compressor and hydraulic turbine drive unit is comprised by a turbine casing 1, a bearing housing 3, a compressor base plate 4 and compressor casing 5. The base plate 4 and bearing housing 3 are secured to the cover plate 2 by screws 6 (only one of which is shown) and the compressor casing 5 is secured to the compressor base plate 4 by screws 7 and washers 8.

A shaft 9 is vertically disposed in the housing and is rotatably mounted in bearings 10 carried by the bearing housing 3. A compressor rotor 11 is mounted on the uppermost end of the shaft 9 and is secured in position by a nut 12 screwed on the end of the shaft. The compressor rotor 11 is rotatable within the compressor chamber 13 which has an axial inlet 14, provided with adjustable guide vanes 15, and a tangential outlet 16.

The lowermost end of the shaft 9 carries two impulse hydraulic turbine wheels 17 which are axially separated by a spacer 18 and are se cured to the shaft by a nut 19 screwed on the end of the shaft 9. The turbine wheels are rotatable in the turbine chamber 20 and each has four associated tangential hydraulic feed nozzles 21 which are located at equal circum ferential spacings in the wall of the turbine casing 1, as can be seen most clearly in Figure 2. The base of the casing 1 is provided with an aperture 22 through which hydraulic fluid may drain from the turbine chamber 20 for return to a hydraulic fluid reservoir. The hydraulic feed pipe to each nozzle is provided with a solenoid operated valve, not shown, which allows the selective cut-out of the nozzles in response to the power output required for the compressor as hereinafter described.

The bearings 10 are lubricated through passages 23 formed in the bearing housing 3 with hydraulic fluid which is bled from the main hydraulic fluid supply line to the nozzles 21.

Hydraulic fluid drains from the bearing housing 3 into the turbine chamber 20 through aperture 24 in the cover plate 2. A deflection plate 25 is mounted between the bearing housing 3 and the compressor base plate 4 and acts to deflect lubricant discharged from the bearings 10 away from the oil seal 26 carried by hardened steel sleeve 32 which prevents ingress of the lubricant into the compressor chamber 13.

The configuration of the turbine wheel 17 can be seen in Figures 3, 4, and 5 from which it will be seen that each turbine blade 33 has two cup-like depressions 34 formed in the face thereof. An alternative turbine wheel shown in Figures 6 and 7 is basically the same as the turbine wheel 17 but differs in that each turbine blade 36 is inclined in the direction of rotation.

A still further alternative turbine blade shown in Figures 8 and 9 is of a different basic confIgura- tion in that the blades 35 are formed by the serrated circumference of the turbine wheel and each blade 36 is provided with a single trough-shape depression 37. It should be understood that the above described alternative turbine wheel configuration are described purely by way of example and other configurations may be used.

The compressor and hydraulic turbine drive unit is preferably mounted directly on to a hydraulic fluid reservoir tank 27, as shown in Figure 10. A hydraulic pump 28 driven by an electric motor 29 draws hydraulic fluid through filter 30 from the tank 27 and delivers it through a pressure regulating valve 31 to the nozzles 21.

A pressure regulating valve is not necessarily essential and it will usually be used only where a variation in pressure is required or where the full output from the pump 28 is not required.

The aperture 22 in the turbine casing 1 is aligned with a similar aperture in the tank 27 and hyhydraulic fluid drains directly from the turbine chamber 20 into the tank 27. Figures 11 and 12 illustrate diagrammatically a control circuit for the nozzles adapted to act co-operatively with the swirl guide vanes 15 disposed in the inlet to the compressor. As the required flow rate through the compressor varies the swirl vanes 15 are rotated to adopt an attitude which optimises the efficiency of the compressor at the flow rate required. The attitude of the swirl vanes 15 is altered quite simply by a control rod 38 which in moving linearly rotates one of the swirl vanes indirectly through rods 40 and levers 41 actuated by lever 39.The control rod 38 is provided with a cam surface 42 which is adapted to contact and operate the three switches 43, 44 and 45 which are in turn adapted to actuate solenoid operated valves 46,47 and 48 respectively. The nozzles 21 of the turbine are arranged in pairs the members of which are associated respectively with the two turbine wheels, and the cam 42 and the switches 43, 44 and 45 are arranged such that the switches operate solenoid operated valves 46, 47 and 48 arranged in the hydraulic supply lines to the nozzles in turn to terminate the hydraulic supply to two, four and six nozzles respectively in correlation with variation in the flow rate through the compressor as determined by the attitude of the swirl vanes 15.If the efficiency of the compressor remained constant over the range of flow rates required, the nozzles 21 would be progressively closed in a linear relationship with the flow rate, so that, for example, at a 50% reduction of flow rate four nozzles would be closed reducing the power output of the turbine by 50% and keeping the speed of rotation of the compressor rotor substantially constant. In practice, however, the efficiency of the compressor will normally fall as the flow rate is reduced and this necessitates an increase in the speed of rotation of the compressor rotor and hence the nozzles 21 would require switching in a non-linear relationship to the compressor flow rate in order to match the power output of the turbine to the required speed of rotation.The speed of rotation of the compressor rotor can be increased by increasing the hydraulic pressure and this is conveniently achieved by selecting the power of the electric motor 29 such that as the hydraulic flow rate through the pump 28 decreases, due to the closing of some of the nozzles 21, the delivery pressure increases by an amount sufficient to increase the speed of rotation of the turbine by the required amount.

The pump will usually be provided with a pressure no lower than the pressure corresponding to the maximum required speed of rotation of the turbine.

The compressor and hydraulic turbine drive unit constructed as hereinbefore described is readily adaptable to cover a range of capacities.

For example the fitting of a compressor with a different capacity to the unit necessitates the replacement of the compressor rotor 11, the compressor base plate 4 and the compressor housing 5. The turbine must be matched to the requirements of the compressor fitted and this can be achieved by fitting tips for the nozzles 21 with an appropriate size aperture. The nozzles aperture size will have to be within predetermined limits and, for example, with a hydraulic pressure of 1750 pounds per square inch will typically be between one millimeter (below which spray is likely to occur) and two and half millimeters (above which it is difficult to accommodate a regular flow pattern around the turbine blades).Furthermore for the smaller capacity compressors it will usually be possible to utilise just one of the two turbine wheels and therefore the possible range extends from a turbine with a single turbine wheel and four nozzles with one millimeter apertures to a turbine with two turbine wheel and a total of eight nozzles with two and half millimeter apertures.

The hydraulic turbine may be powered by any commercially available hydraulic fluid and we have found that most of such fluids can be utilised to lubricate the bearings of the unit.

The aforementioned feature of having a hydraulic drive turbine mounted on a shaft which is rotatably mounted in bearings which are lubricated by the hydraulic fluid forms the subject of our co-pending British Patent Application 39465/75. (Serial No. 1561083.

The present invention is further concerned with small turbine wheels having a putch circle diameter of 1.3 inches (e.g. 1 to 1.2 inches) and a maximum overall diameter of 1.6 inches running at a minimum operationa speed of 10,000 r.p.m. and may be about 50,000 r.p.m. The nozzles have openings not exceeding 2.5 millimeters in diameter e.g. 1 to 2 millimeters and at least two nozzles are provided at each wheel preferably 4 or 6. The turbine is to be used with a pump capable of delivering from 8 to 60 gallons of hydraulic fluid per minute.

The hydraulic fluid used both for the turbine and for the lubrication of the bearings is well known in engineering by this name and is the kind used in hydraulic torque converters and hydraulic brakes and is non-aqueous and generally a hydrocarbon or ester type fluid which we find to be suitable for lubrication of bearings. These fluids have anti-foaming properties and are stable against oxidation.

With constant pump output, the shutting of one or more nozzles increases the pressure flow from the others and produces an increased horsepower output.

For the purpose of the present invention the turbine is used to drive a gas-moving device or compressor coupled to apparatus other than refrigeration systems and is especially used for conveying solid particulate material (.e.g. coal, flour or chemicals) along pipes. Another application of the invention is for providing suction i.e. the intake of the compressor is connected to the apparatus requiring suction e.g. a road sweeping machine.

The problem of disposing of the large quantity of fluid leaving the turbine is accomplished by using a turbine on a vertical axis and fixing the turbine casing to a reservoir tank so that an opening in the bottom of the casing is located directly over an opening in the top of the reservoir tank so that the fluid from the turbine falls directly by gravity into the tank.

Figure 13 shows a modification in which the shaft 9 drives an axial compressor 11 A.

Figure 14 shows the output 16 of Figure 1 applied to conveying of solid particulate material. The material is fed from a hopper 50 to a rotary distributor 51 within a housing 52.

The distributor is driven by a shaft 53 and has passages 54 (e.g. six passages) therein which receive material successively from the hopper and transfers it to a position in line with a pipe 58 connected with the output 16 and in line with a pipe 59 leading to a desired location.

WHAT WE CLAIM IS:1. A rotary gas moving equipment wherein a rotary gas moving member is driven by a hydraulic turbine comprising one or more bladed turbine rotors mounted on a shaft rotatably mounted in a housing, a plurality of nozzles spaced around the or each turbine rotor arranged to direct tangential jets of hydraulic fluid at the blades of the or each turbine rotor, these nozzles urging the rotor in a common direction, and onoff control means for varying the number of nozzles which are operational.

2. Equipment according to claim 1 wherein the means for selectively terminating the flow of hydraulic fluid through the nozzles comprises solenoid operated valves in hydraulic fluid supply lines to the nozzle.

3. Equipment according to any one of the preceding claims wherein four nozzles are arranged around the or each turbine rotor.

4. Equipment according to any one of the preceding claims wherein the shaft is mounted in bearings which are lubricated by hydraulic fluid bled from hydraulic fluid supply means for the turbine.

5. Equipment according to any one of the preceding claims wherein the housing is mounted on a hydraulic fluid reservoir tank and has an aperture whereby hydraulic fluid may drain from the housing into the tank.

6. Equipment according to any one of the preceding claims wherein the or each turbine rotor is mounted on a shaft on which a rotor of a compressor forming the gas moving member is also mounted.

7. Equipment according to any of the preceding claims wherein the means for varying the number of nozzles which are in operation, is arranged to act cosperatively with variable attitude swirl vanes disposed in an inlet to a compressor driven by the turbine and forming the gas moving member.

8. Equipment according to claim 7, wherein a control rod adapted to operate the swirl vanes has a cam surface adapted to actuate switches of a control circuit for the means for varying the number of nozzles which are operational.

9. Equipment as claimed in any of the preceding claims coupled to a compressor forming the gas moving member which in turn is coupled to equipment for conveying solid particulate material along a pipe.

10. Equipment as claimed in any of the preceding claims coupled to a compressor forming the gas moving member the intake of which is coupled to equipment requiring suction.

11. Equipment as claimed in any of the preceding claims wherein the nozzle openings are less than 2.5 millimeters diameter and are fed by a pump delivering 8 to 60 gallons per minute, the or each turbine rotor has a pitch circle diameter less than 1.3 inches, the turbine rotor being adapted to rotate operatively at a speed exceeding 10,000 r.p.m.

12. Equipment as claimed in claim 1 having a plurality of turbine rotors adjacent rotors being spaced apart at least one and a half times the axial width of a rotor.

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Claims (12)

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1 applied to conveying of solid particulate material. The material is fed from a hopper 50 to a rotary distributor 51 within a housing 52.

The distributor is driven by a shaft 53 and has passages 54 (e.g. six passages) therein which receive material successively from the hopper and transfers it to a position in line with a pipe 58 connected with the output 16 and in line with a pipe 59 leading to a desired location.

WHAT WE CLAIM IS:1. A rotary gas moving equipment wherein a rotary gas moving member is driven by a hydraulic turbine comprising one or more bladed turbine rotors mounted on a shaft rotatably mounted in a housing, a plurality of nozzles spaced around the or each turbine rotor arranged to direct tangential jets of hydraulic fluid at the blades of the or each turbine rotor, these nozzles urging the rotor in a common direction, and onoff control means for varying the number of nozzles which are operational.

2. Equipment according to claim 1 wherein the means for selectively terminating the flow of hydraulic fluid through the nozzles comprises solenoid operated valves in hydraulic fluid supply lines to the nozzle.

3. Equipment according to any one of the preceding claims wherein four nozzles are arranged around the or each turbine rotor.

4. Equipment according to any one of the preceding claims wherein the shaft is mounted in bearings which are lubricated by hydraulic fluid bled from hydraulic fluid supply means for the turbine.

5. Equipment according to any one of the preceding claims wherein the housing is mounted on a hydraulic fluid reservoir tank and has an aperture whereby hydraulic fluid may drain from the housing into the tank.

6. Equipment according to any one of the preceding claims wherein the or each turbine rotor is mounted on a shaft on which a rotor of a compressor forming the gas moving member is also mounted.

7. Equipment according to any of the preceding claims wherein the means for varying the number of nozzles which are in operation, is arranged to act cosperatively with variable attitude swirl vanes disposed in an inlet to a compressor driven by the turbine and forming the gas moving member.

8. Equipment according to claim 7, wherein a control rod adapted to operate the swirl vanes has a cam surface adapted to actuate switches of a control circuit for the means for varying the number of nozzles which are operational.

9. Equipment as claimed in any of the preceding claims coupled to a compressor forming the gas moving member which in turn is coupled to equipment for conveying solid particulate material along a pipe.

10. Equipment as claimed in any of the preceding claims coupled to a compressor forming the gas moving member the intake of which is coupled to equipment requiring suction.

11. Equipment as claimed in any of the preceding claims wherein the nozzle openings are less than 2.5 millimeters diameter and are fed by a pump delivering 8 to 60 gallons per minute, the or each turbine rotor has a pitch circle diameter less than 1.3 inches, the turbine rotor being adapted to rotate operatively at a speed exceeding 10,000 r.p.m.

12. Equipment as claimed in claim 1 having a plurality of turbine rotors adjacent rotors being spaced apart at least one and a half times the axial width of a rotor.