WO1995005067A1

WO1995005067A1 - Fluid distributor

Info

Publication number: WO1995005067A1
Application number: PCT/GB1994/001742
Authority: WO
Inventors: Joseph Gardner
Original assignee: Timber-Land Products Limited
Priority date: 1993-08-12
Filing date: 1994-08-09
Publication date: 1995-02-23
Also published as: AU7347994A; GB9316754D0

Abstract

A distributor for intermittently delivering a flow of sewage sludge to each of series of injectors mounted on respective legs that are pulled through ground to be injected, each leg reciprocating in a vertical direction to open voids beneath the ground into which sludge can be injected. The distributor is in the form of a casing (1) defining outlets (2, 3, 4, 5) each of which is connected to a respective injector and a rotor (6) which turns within the casing (1) so as to alternately obstruct and open the outlets (2, 3, 4, 5) as the rotor (6) turns. The rotor supports a series of radially projecting valve members (12, 13, 14, 15) each of which is axially aligned with a respective outlet. Each valve member defines a part of the surface of a cylinder which when facing the respective outlet obstructs that outlet. The leading edges (17) of the valve members (12, 13, 14, 15) may be sharpened to scrape away any material which may become lodged on the inside surface of the casing or in an outlet.

Description

FLUID DISTRIBUTOR

The present invention relates to a distributor for intermittently delivering a fluid flow to each of a plurality of outlets.

There is a rapidly increasing demand for equipment which is capable of injecting sewage sludge into farmland in a controlled manner such that large volumes of sludge can be disposed of without significant risk of the sludge running off the land and polluting waterways. Experience has proved that good results can be achieved using an injector mounted on a subsoil aerator of the type described in International Patent Publication No. WO87/04893. The subsoil aerator described in that document comprises a blade which is reciprocated relative to a tractor-mounted frame as the blade is pulled through the ground by the tractor, the blade reciprocating in a vertical plane such that it lifts the soil to provide a cavity into which sludge can be injected and breaks up the soil so that the injected sludge is rapidly absorbed. As described in co-pending British Patent Application No. 9206955.8, preferably the sludge is injected intermittently, the initiation of injection being synchronised with a lifting movement of the aerator blade so that the sludge is injected into a ready-formed sub-soil cavity. To achieve intermittent injection, sludge has been delivered to injectors from a sludge distributor.

The known sludge distributor comprises an outer tubular casing which typically defines four outlets, each connected to a respective sub-soil injector. A hollow rotor is rotatably mounted within the casing and defines a series of apertures, one in respect of each casing outlet, the apertures being axially aligned with the respective casing outlets such that as the rotor turns sludge is distributed to each outlet only whilst that outlet is overlapped by the respective rotor aperture. In one arrangement only one outlet is in communication with the interior of the rotor at any one time, but in other arrangements where very high volumes of flow are required it may be that two or more of the outlets are simultaneously in communication with the interior of the rotor. In all cases, however, each outlet is isolated from the interior of the rotor for a period of time during each rotation of the rotor. The rotor is driven in synchronism with the movement of the sub-soil aerator blades and thus by appropriate

SUBSTITUTE SHEET (RULE 26} disposition of the apertures and outlets it can be arranged that each outlet comes into communication with the interior of the rotor just as the respective blade is being lifted.

The known sludge distributor has proved very effective but unfortunately has a tendency to jam. In the known arrangement the rotor supports O-rings in grooves formed in the rotor, the O-rings bearing against the inner wall of the casing. A pair of O-rings is located on each side of each outlet so that a nominally isolated cavity is formed in the gap between the rotor and casing between each adjacent pair of outlets and between the endmost outlets and the ends of the casing. This cavity is filled with grease through suitably located grease nipples. It has been found however that the sewage sludge becomes so tightly packed between the rotor and casing adjacent the O-rings that after only a relatively short time in operation (typically a few hours) the rotor can no longer be turned within the casing. The distributor assembly then has to be dismantled for cleaning and this is clearly highly disadvantageous.

It is an object of the present invention to obviate or mitigate the problems outlined above.

According to the present invention, there is provided a distributor for intermittently delivering a fluid flow to each of a plurality of outlets, the distributor comprising a tubular casing defining the outlets, and a rotor rotatably mounted within the casing such that each outlet is alternately obstructed and opened as the rotor turns within the casing, wherein the rotor supports a series of axially spaced radially projecting valve members each of which is axially aligned with a respective outlet, each valve member defining a part of the surface of a cylinder which when facing a respective outlet obstructs that outlet.

Preferably, each valve member has a sharp leading edge in the direction of rotation of the rotor such that as the edge sweeps across the respective outlet any fibrous material lodged in the outlet is scraped away.

The only restricted areas defined between the rotor and the casing are between the radially outer surfaces of the valve members and the inner surface of the casing and therefore there is insufficient space available to enable material to build up and cause the rotor to jam. In particular, the sharpened leading edge of the rotor ensure that any material which does build up is scraped away as the rotor turns in the normal manner.

Preferably each valve member is in the form of a section of a tube supported by at least one radially extending limb mounted on an axially extending drive shaft.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a part sectional view through a rotor in accordance with the present invention;

Fig. 2 is a side view of the rotor incorporated in the distributor of Fig. 1; and

Figs. 3, 4, 5 and 6 are views taken on the lines 3-3, 4-4, 5-5 and 6-6 of Fig. 2.

Referring to Fig. 1, the illustrated distributor comprises a tubular casing 1 onto which outlets 2, 3, 4 and 5 are welded, each outlet communicating with the interior of the casing through a respective circular aperture which penetrates the casing wall. A rotor is housed within the casing, the rotor comprising a drive shaft 6 mounted at one end in a bearing 7 supported on a perforated radially extending disc 8 and at the other end in a bearing 9 mounted on the end of the casing. A splined shaft 10 is received within a splined sleeve 11 welded to one end of the drive shaft and the rotor is turned by connecting to the shaft 10 an appropriate drive coupling linked for example to a power take-off on an agricultural tractor.

Four valve members 12, 13, 14 and 15 are spaced apart along the length of the drive shaft, each valve member being axially aligned with a respective outlet. As can best be seen from Figs. 3 to 6, each valve member is in the form of a part of the wall of a tube and is supported on the shaft 6 by a radially extending limb 16. Each valve member extends around slightly less than half of the circumference of the drive shaft 6 and the limbs 16 are offset relative to each other such that the four valve members are offset by 90° relative to each other around the shaft 6.

The leading edge 17 of each valve member is sharpened such that as it moves across a respective outlet it cuts away any material lodged in the outlet and projecting into the casing. Thus on each rotation of the rotor material which might otherwise cause the rotor to jam is cleaned away in an effective manner.

In use, fluid is pumped into the casing through the perforations in the end plate 8 (Fig. 1). That fluid then flows to those outlets which are not obstructed. With the relative disposition of the components shown in Fig. 1, outlet 4 is fully opened, outlet 5 is fully closed, outlet 3 is about to be closed and outlet 2 is in the process of being opened.

It will be appreciated that the valve member 12, 13, 14 and 15 could extend around the shaft to a greater or lesser extent than in the illustrated example. If each valve member extended around for example 270°, it would be appropriate to provide two radially extending limbs to provide adequate support.

Claims

1. A distributor for intermittently delivering a fluid flow to each of a plurality of outlets, the distributor comprising a tubular casing defining the outlets, and a rotor rotatably mounted within the casing such that each outlet is alternately obstructed and opened as the rotor turns within the casing, wherein the rotor supports a series of axially spaced radially projecting valve members each of which is axially aligned with a respective outlet, each valve member defining a part of the surface of the cylinder which when facing the respective outlet obstructs that outlet.

2. A distributor according to claim 1, wherein each valve member has a sharp leading edge in the direction of rotation of the rotor such that as the edge sweeps across the respective outlet any material lodged in the outlet is scraped away.

3. A distributor according to claim 1 or 2, wherein each valve member is in the form of a section of a tube supported by at least one radially extending limb mounted on an axial drive shaft.

4. A distributor substantially as hereinbefore described with reference to the accompanying drawings.