GB2224544A

GB2224544A - Device for extracting energy from a fluid flow, having a rotatable baffle

Info

Publication number: GB2224544A
Application number: GB8825576A
Authority: GB
Inventors: Denis Simon Speyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-11-02
Filing date: 1988-11-02
Publication date: 1990-05-09
Also published as: GB8825576D0

Abstract

A baffle 10 is disposed across the diameter of a vertical cylindrical chamber 14 and oscillated or rotated continuously in one direction to cross inlet and outlet openings 31 and 32, so that water rises in half of the chamber and falls in the other half thus displacing air through a duct 25. A self rectifying air turbine 26 generates power. The chamber openings connect upstream and downstream to a river weir and the chamber may be installed on land or on the river bed. The baffle is supported in bearings 15, 17 and 18, it has seals along its tips 20 and bottom 21, and it is driven by an actuator 22. The baffle and water openings may be fitted with cutting knives and anvils to prevent the baffle being jammed by trash. The baffle may be fabricated as a box beam in glass reinforced plastic. <IMAGE>

Description

ROTATABLE BAFFLE This invention relates to a rotatable baffie mounted within a chamber and used to direct water flow, so that rising and falling water levels give rise to an air flow in a device for generating powder.

A known device for generating power at riser sites, with low head drops, has means of directing water flow into and out of chambers to create rising and falling water columns, which set up an oscillating air flow through a self-rectifying air turbine. Relatively large volumes of water have to be directed, with the result that the valves have to be large. The cost of normal industrial valves is therefore excessive.

Furthermore the valves have to be autonatically actuated in a cycle of operations that lasts only a ieu seconds.

The actuator system for large escillating valves has to overcome the inertia of the moving parts, as well es the hydraulic forces, so the cost of the actuator becomes excezsive. Continuously moving valves are preierable because the actuator system has then only to overcone friction and the hydraulic forces.

According to the present invention there is provided a baffle, disposed right across the diameter of a vertical cylindrical chamber, and able to be rotated about its central vertical axis. either to-and-iro over an ar@ or continuously in one direction.

The baffle divides the chamber in half, and the ail turbine is connected betwcen the two haives. Wator rises in the half of the chamber connected to the inler opening, and falls in the opposite outlet halt. When the ba@@ie is moved across the openings the full half of the chamber begins to empty and the empty half begins to fill. The air flow through the turbine responds to the rise and -al of water level in the two halves of the chamber.

The whole assembly may be installed partly below ground close to a weir, with open or covered channels connecting it with the river upsteam and downstream of the we-r.

Alternatively it may be sunk in the river, resting, or a suitable surface on the river bed, uith one connection open to the river and the other ducted through the weir.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 chows a vertical oross-section cf the chamber through the axis of the ar turbine and air duct mounted above it, the baffle being shown in elevation intermediate position; Figure 2a shows a plan views of the chamber and the oscillating baffle, with the chamber cover removed but with the air duct entry and outlet positions indicated by dashed lines; Figure 2b shows the view of figure 2a but indicates the baffle in the alternative extreme position;; Figure 3a shows a plan View of the chamber and the continuously rotating baffle, with the cnamber cover removed but with the air duct entry and outlet positions indicated by dashed lines; Figure 8b shows the view of figure 8a but indicates the rotating baffle in a later position, Figure 4 shows an isometric view of the baffle a specific mode of construction.

Refering to the drawing the baffle 10 has stub shafts top 11 and bottom 12. It- in mounted in the chamber Ii with the stub shafts located in bearing 15 in the cover 16 and in bearing 17 in the bottom ot the chamber. The bottom bearing carries the weight of the baffle on a thrust surface 18. The baffle has seals along its tis 20 and along its bottom 21 to limit the water leakage t the edges. The baffle is driven by a rotary actuator 22 connected to the top stub shaft. The actuator amy b@ mounted on the shaft, with a flexibly jointed arm to provide torque reaction.

The air duct 25 mounted on top of the chamber cover carries the self-rectifying air turbine 26 and directcoupled electric generator 27.

The chamber 14 is installed with its inside top surface just above the highest water level 30. The heights of the inlet opening 31, connected with the high water level, and outlet opening 32, connected with the low water level 33, are indicated on figure 1. Their positons in plan relative to the air duct 25 depend on whether the baffle is to oscillate or rotate continuously, and are shown on figures 2 & 3.

The oscillating baffle shown in figure 22 has an arc of movement 36. Water flows to fill side 87 and empty side 38, creating an air flow @through the turbine 37 t'' When the baffle has moved to the other end of the ar@, as in figure 2b, side 38 filis, side 37 empties and the air flow reverses 38 to 37, Actuation of the bafile movemen may be initiated by a control system such as high @eve.

probes mounted one on each side.

The continuously rotating baftie shown in figure 8a a water to fill side 40 and empty s.de 41. These sics move round with the baffle rotation 42 until the position cf figure 3b is reached. The openings are then cracked open so water flows in 43 to fill side 41 and out 44 to empty side 40. At this time secondary flows 45 & 48 will help to wash through any trash in suspension to avoid it jamming the baffle. As an additional precaution cutting knives and anvils may be installed at baffle tips 4. & BR< 48 and water openings 49 & 50. Air flow through the turbine is interrupted as the baffle crosses the openings but otherwise is always in the direction fror inlet 51 to outlet 52.

The baffle 10 may be fabricate as a box team 1 Is reinforced plastic (GRP) as shown in figure 4 to witnstand the alternating hydrostatic forces. which cause bending in two perpendicular dir@ctions. internal ribs 55 end 58, together with the skin on each side 57 and 58. resist bending in the vertical and horizontal planes respecti ely.

Spacing, of ribs 56 may be varied to resist that increasing hydrostatic pressure as the immersed depth increases. The chamber 15, chamber cover and air duct may also fabricated in GRP.

Claims

1. A baffle, disposed right across the diareter of a vertical cylindrical chamber, able to be rotated about its central vertical axis to iove across a water inlet opening and an opposing outlet opening.

2. A baffle as claimed in clam 1 which is rotated to-and-fro over an arc across the openings so that water rises in the half of the chamber connected to the inlet opening and falls in the opposite outlet half.

3. A baffle as claimed in claim 1 which is rotated continuously in ope direction so that water rises in the half of the chamber connected to the inlet opening and falls in the opposite outlet half.

4. A rotatable baffle as claimed in claim 1, and claim 2 or 3, wherein the whole assembly is installed partly below ground close to a weir, with open or covered channels connecting it with the river upstream or downstream of the weir.

5. A rotatable baffle as claimed in claim 1, and claim 2 or 3, wherein the whole assembly is installed on a suitable surface on a river bed with one connection open to the river and the other ducted through a weir.

6. A rotatable baffle as claimed in claim 1, and claim 2 or 3, wherein a self rectifying air turbine is connected between the air space on each half of the chamber to generate power.

7. A rotatable baffle as claimed in claim 1, wherein the baffle has stub shafts top and bottom supported in bearings mounted in the cover and bottor of the chamber.

8. A rotatable baffle as claimed in claim 1, wherein the baffle has seals along its tips and along its bottom to limit the water leakage at the edges.

9. A rotatable baffle as claimed in clam 1, wherein the baffle is driven by a rotary actuator connected to the top stub shaft.

10. A rotatable baffle as claimed in claim 1 and claim 3, wherein cutting knives and anvils are installed at baffle tips and water openings to prevent any trapped trash from jamming the baffle.

11. A rotatable baffle as claimed in claim 1, wherein the baffle is fabricated as a box beam in glass reinforced plastic, with vertical and horizontal internal ribs together with a skin on each side to resist bending in vertical and horizontal planes respectively.

12. A rotatable baffle as claimed in claim 1 and claim 11, wherein the spacing of horizontal ribs is varied to resist the increasing hydrostatic pressure as the immersed depth increases.

13. A rotatable baffle substantially as described herein with reference to figures 1 to 4 of the accompanying drawing.