GB2241770A

GB2241770A - Fluid flow reversing valve

Info

Publication number: GB2241770A
Application number: GB9005311A
Authority: GB
Inventors: Graham Frank Clifford
Original assignee: FONG S NATIONAL ENGINEERING CO
Current assignee: FONG S NATIONAL ENGINEERING CO
Priority date: 1990-03-09
Filing date: 1990-03-09
Publication date: 1991-09-11
Anticipated expiration: 2010-03-09
Also published as: HK30796A; GB2241770B; CN1024713C; CN1054822A; GB9005311D0

Abstract

A fluid flow reversing valve comprises a housing (1), a tube (2) fixed in the housing, and a tube (3) rotatable in the fixed tube (2), the ends of the tube (2) registering with housing apertures (1c, 1d) for connection to the discharge and suction sides of a pump. The rotatable tube (3) has ports (3b, 3c) separated by a partition (3a), these ports being selectively aligned with ports (2a, 2b) in the fixed tube (2). The apertured end (1e) of the housing and the port (2a) are connected in use to yarn-dyeing apparatus. <IMAGE>

Description

FLUID FLOW REVERSING VALVE The present invention relates to a fluid flow reversing valve for connect ion to a pump so as to direct the discharge from the pump optionally in one direction or in the opposite direction about a fluid flow circuit. The invention relates particularly though not exclusively to valves for use in apparatus for dyeing yarn.

Yarn which is to be dyed is traditionally presented for the dyeing operation wound tightly onto a permeable tubular core to form a yarn package. One well-known apparatus for use in dyeing yarn presented in this fashion comprises; (a) a cylindrical pressure vessel; (b) vertical spindles within the vessel, on each of which a number of packages may be received one above the other; (c) a pump for driving the dyeing liquid; and (d) a liquid flow reversing valve connected to the pump, for directing liquid alternately along a first flow path up through the hollow core of the spindles and out through perforations in the spindles, and through the packages of yarn, and back to the suction side of the pump, and a second flow path which is the opposite of the first. In operation, the liquid flow reversing valve is repeatedly reversed so as to achieve uniform dyeing of the yarn.

Various different constructions of liquid flow reversing valve have been used, the most common being an ell of short radius, one end of which is pivotally connected to a manifold leading to the spindles, and the other end of which may be connected alternatively to the discharge side of the pump or the suction side of the pump.

Existing liquid flow reversing valves of the above type may suffer from one or more of a number of possible disadvantages. A first possible disadvantage is that the valve which is generally located at the bottom of the dyeing apparatus may be quite large to the extent that the valve limits the area available at the bottom of the dyeing apparatus through which services to heat exchangers may be provided. A second possible disadvantage is that the valves may be expensive to manufacture. A third possible disadvantage is that when the dyeing apparatus is used to dye a partial load, the valve and associated pump may be inefficient in terms of the power consumed and the cycle time.A fourth possible disadvantage is that the valve may require considerable maintenance because it is located at the very bottom of the yarn dyeing apparatus, where it is subject to all water and chemical leakages, and in particular its operating mechanism may be vulnerable to leakages from the packed gland which allows rotation of the ell. A fifth possible disadvantage is that the valve may be difficult to maintain, because the working area for carrying out the maintenance is subject to the leakages mentioned above, and is also frequently located in a region of limited access very close to the ground, to facilitate loading of packages of yarn into the cylindrical housing from above and is uncomfortable due to a wet floor and downward leakage.A sixth possible disadvantage is that the entire vessel may have to be lifted off its station to enable maintenance to be carried out on the valve.

We have now found it possible to provide an improved valve, which is more compact thereby leaving a greater available surface area at the bottom of the dyeing apparatus, is more economic to manufacture, is efficient when dyeing both full and partial loads, may also serve as a support or plinth for the dyeing apparatus, requires less frequent maintenance and is easier to maintain.

According to the present invention there is provided a fluid flow reversing valve comprising: (a) a valve housing including a port for connection to one end of a fluid flow circuit; (b) a fixed tubular member extending across the valve housing from a first aperture for connection to the discharge side of a pump, to a second aperture for connection to the suction side of the pump; (c) a first port in the fixed tubular member for allowing fluid communication between the fixed tubular member and the valve housing; (d) a second port in the fixed tubular member for connection to the other end of the fluid flow circuit; (e) a rotatable tubular member which is a close fit within the fixed tubular member, and includes a partition dividing the interior into two regions, and a first port in one region and a second port in the other region; and (f) a rotating mechanism for rotating the rotatable tubular member about its axis between two different orientations, a first orientation in which the ports of the rotatable tubular member are in register with those of the fixed tubular member so as to direct flow from the discharge side of the pump to one end of the fluid flow circuit, and a second orientation in which the ports of the rotatable tubular member are in register with those of the fixed tubular member so as to direct fluid in the opposite direction along the fluid flow path.

Preferably the valve housing is of upright cylindrical shape, the fixed and rotatable tubular members extend horizontally, and the ports in the fixed and rotatable tubular members are of elliptical shape, to facilitate liquid flow.

Preferably one port of the rotatable tubular member is smaller than the other. The valve may be connected so that fluid from the discharge side of the pump flows through this smaller port, and fluid returns to the suction side of the pump through the larger port, so that there is always fluid available for the pump.

One embodiment of a fluid flow reversing valve according to the invention suitable for use in yarn dyeing apparatus will now be described more particularly, by way of non-limiting example only, with reference to the accompanying drawing which shows an exploded perspective view of the valve.

Referring to the drawing, the valve comprises a housing 1, a fixedtubular member 2 extending horizontally across the housing, a rotatable tubular member 3 which is a close fit within the fixed tubular member, and a rotating mechanism 4 for rotating the rotatable tubular member. The housing 1 comprises a cylindrical sidewall la, which serves as a compact plinth on which the yarn dyeing apparatus may be mounted, a base lb, apertures lc and ld for connecting the ends of the fixed tubular member 2 to the discharge and suction sides respectively of a pump (not shown) and an open top le for connection to one end of a fluid flow circuit extending through the yarn dyeing apparatus. The fixed tubular member 2 comprises an upper port 2a, a guide 5 above the upper port 2a for connection to the other end of the fluid flow circuit, and a lower port 2b connecting the interior of the fixed tubular member to the interior of the housing 1. The rotatable tubular member 3 includes a partition 3a dividing the interior thereof into separate regions, and a first port 3b in one region, and a second port 3c in the other region.The rotating mechanism 4 comprises a spindle one end of which is connected to the rotatable tubular member 3, and which extends along pipework (not shown) forming part of the fluid flow circuit, the other end of the spindle projecting out of the pipework through a packed gland situated at a location remote from the valve housing, the projecting end being provided with a control mechanism for rotating the spindle about its axis so as to effect rotation of the rotatable tubular member 3.

In operation, with the rotatable tubular member so oriented that port 3b is in register with port 2a, and port 3c is in register with port 2b, dyeing liquid from the discharge side of the pump enters aperture lc, passes along the fixed tubular member 2 into the rotatable tubular member 3, is deflected upwardly by partition 3a, and passes through ports 3b and 2a, through guide 5, and into the dyeing apparatus, and then returns through port le, through apertures 2b, 3c and is deflected by partition 3a to the suction side of the pump. When the orientation of the inner tubular member is changed so that port 3b is in register with port 2b, and port 3c in register with port 2a, the fluid follows the reverse path, entering the dyeing apparatus through port le and returning through guide 5.

The port 3b is smaller than the ports 3c, 2a, 2b, and thus protects the pump because the discharge from the pump is restricted relative to the suction, so that there is always liquid available for the pump.

The internal diameter of the inner tubular member 2 corresponds to the diameter of the suction side of the pump, and other dimensions of the valve are in proportion, so that the valve has the minimum dimensions consistent with delivering the fluid flow from the pump.

Because the valve is a throttle-type valve rather than a by-pass valve, in the case of partial loads, either the power consumed may be reduced or the cycle time reduced.

The pump may be electrically powered and may be provided with an ammeter (not shown) to measure power consumption.

Measurement of the power consumption of the pump in driving fluid through the throttle valve type allows accurate determination of the volume of liquid which has been driven through the valve to the yarn dyeing apparatus. Accordingly, the yarn dyeing apparatus can be more accurately controlled than was the case with prior art reversing valves.

The valve not only leaves a greater surface area at the bottom of the dyeing apparatus through which services may be provided, but can also itself be used to provide services by means of connections to the sidewall la of the cylindrical housing 1.

Claims

l. A fluid flow reversing valve comprising : (a) a valve housing including a port for connection to one end of a fluid flow circuit; (b) a fixed tubular member extending across the valve housing from a first aperture for connection to the discharge side of a pump, to a second aperture for connection to the suction side of the pump; (c) a first port in the fixed tubular member for allowing fluid communication between the fixed tubular member and the valve housing; (d) a second port in the fixed tubular member for connection to the other end of the fluid flow circuit; (e) a rotatable tubular member which is a close fit within the fixed tubular member, and includes a partition dividing the interior into two regions, and a first port in one region and a second port in the other region; and (f) a rotating mechanism for rotating the rotatable tubular member about its axis between two different orientations, a first orientation in which the ports of the rotatable tubular member are in register with those of the fixed tubular member so as to direct flow from the discharge side of the pump to one end of the fluid flow circuit, and a second orientation in which the ports of the rotatable tubular member are in register with those of the fixed tubular member so as to direct fluid in the opposite direction along the fluid flow path.
2. A fluid flow reversing valve according to claim 1 in which the valve housing is of upright cylindrical shape, the fixed and rotatable tubular members extend horizontally, and the ports in the fixed and rotatable tubular members are of elliptical shape.
3. A fluid flow reversing valve according to claim 1 or claim 2 in which one port of the rotatable tubular member is smaller than the other.
4. A fluid flow reversing valve according to any one of the preceding claims in combination with an electrically powered pump provided with an instrument for measuring electrical power consumption.

5 A fluid flow reversing valve substantially as herein described with reference to and as shown in the accompanying drawings.