GB2132318A

GB2132318A - Valve

Info

Publication number: GB2132318A
Application number: GB08331920A
Authority: GB
Inventors: Raymond Derek Kiley
Original assignee: KILARD CO
Current assignee: KILARD CO
Priority date: 1982-12-01
Filing date: 1983-11-30
Publication date: 1984-07-04
Also published as: GB8331920D0; GB2132318B

Abstract

An isolating damper valve apparatus for mounting between a riffle box assembly and a delivery conduit for a pulverised coal/air mixture comprises a cylindrical casing (10) pivotally mounting a pair of valve blades (32) which may be locked in closed position by a piston/cylinder assembly 44. On the upstream side the blades (32) are protected by a guard (42) of hard wearing material. The blades (32) may be geared to rotate together under a powered or manually-operated drive arrangement. <IMAGE>

Description

SPECIFICATION Valve apparatus This invention relates to a valve apparatus for use especially but not exclusively in an arrangement for the transportation of a pulverised cool/air mixture.

In previously proposed transport arrangements for such a mixture, a riffle box for separating the mixture into different flow paths has outlets connected with conduits through one-way damper valves which close the riffle area when flow of the material is stopped. Valves of the butterfly type cannot safely be used to isolate the riffle area in the event of, for example, fire breaking out, as the sealing joints cannot be protected from abrasion and/or erosion. When flap valves are used combustion gases in the event of a fire can force the damper valves open and flow therefore through the conduits. The valve casings cannot be constructed with axial lengths less than the crosssectional areas of the valves.

According to the present invention there is provided a valve apparatus for use in an arrangement for transporting a pulverised coal/air mixture, the valve apparatus comprising a valve casing through which the material can flow, valve means having a pair of valve parts pivotally mounted in the casing to be movable between an open position wherein both valve parts extend substantially downstream of the direction of material flow, and a closed position wherein the valve parts extend transversely of the direction of material flow so as to prevent flow through the casing, and means provided to releasably lock the valve parts in the closed position.

Preferably means for pivotally mounting the valve parts extend across the casing and have a guard associated therewith on the upstream side so as to protect the mounting means against the mixture passing through the casing. The guard may be formed of a hard wearing material and may be of triangular configuration with the apex facing upstream in the direction of flow.

Preferably also the valve parts are mounted on respective rotatable members extending across the casing, a drive arrangement for the rotatable members being provided.

Advantageously, the casing has such a dimension in the flow direction that the valve parts project therefrom in the open position for entry into a conduit connectible downstream of the casing.

Further the casing may have internal valve seats for seating the valve parts in the closed position, and sealing means being associated with each valve seat.

In addition the locking means may comprise a piston/cylinder assembly which is associated with each valve part and wherein a piston can project internally of the casing when the respective valve part is in the closed position, so as to overlie the valve part on a downstream side thereof.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 is an end elevation of an isolating damper valve apparatus according to the invention, with one blade part shown in an open position and the other in a closed position; and Fig. 2 is a sectional side elevation of the apparatus of Fig. 1.

Referring to the drawings, an isolating damper valve apparatus is adapted to be mounted between a riffle box assembly (not shown), and a delivery conduit (not shown) for a pulverised coal/air mixture. The apparatus comprises a cylindrical casing 10 defining a profiled internal wall 1 2 as hereinafter described and having an annular peripheral flange 14 at each end thereof adapted to receive bolts 1 6 or the like to mount the casing 10 on the riffle box assembly and the delivery conduit. The casing 10 may be formed, for example, of mild steel with a coating of a good wearing material internally thereof.

Extending through the casing 10, at a diametral location thereof, are a pair of parallel shafts 18, 20 projecting externally of the casing 10 at one end into a transmission housing 22 and at the other end into a housing 24, and having reduced diameter end sections 26 mounted in suitable bearings 28 to enable the shafts 18, 20 to be rotatable. At said one end the shaft 20 is operatively connected in the transmission housing 22 with a drive motor 30, and at the other end the shafts 18, 20 are geared together so as to be driven simultaneously on operation of the motor 30.

Each of the shafts 18, 20, within the valve casing 10, rigidly mounts a valve member comprising a blade 32 and a support 34, corresponding ends of the blade 32 and the support 34 embracing the respective shaft and being bolted thereto, the support 34 being secured at its free end to the blade 32 at a location substantially midway between the respective shaft and the free end of the blade 32.

Each of the blades 32 is adapted to be moved, by rotation of the respective shaft 1 8, 20, between a closed position extending transversely of the valve casing 10, as shown by the lower blade 32 in Fig. 2, and an open position facing downstream of the direction of flow through the valve casing 10 as shown by the upper blade 32 of Fig. 2. The internal wall of the casing 10 at each side of the shaft arrangement defines a peripheral seat 36 having a co-extensive seal 38 and adapted to seat the respective valve blade 32 in the closed position. At the downstream side from the seat 36, the internal wall 12 is profiled to substantially correspond with the path of movement of the free edge of the respective valve blade 32. The valve blades 32 are formed of a hard wearing material.

On the upstream side the shafts 18, 20 are shielded from contact with the coal/air mixture to minimise wear, by a plate 40 extending across the casing 10 and mounting a guard 42 formed of a hard wearing material and of substantially triangular configuration with the apex pointing upstream in the direction of flow. The guard 42 deflects the mixture to either side of the shafts 18, 20 and, to minimise reduction in pressure created by the presence of the guard 42, the internal wall of the valve casing 10 upstream of the valve seat 36 is suitably profiled.

At diametrically opposed locations on the cylindrical wall of the valve casing 10, substantially 90 removed from the location of the shafts 18, 20, there are provided valve locking arrangements. Each of the latter comprises a piston/cylinder assembly 44, preferably pneumatic, having a cylinder part 46 mounted on the external wall of the valve casing 10, the piston 48 being arranged to be movable in a guide sleeve 50 extending through the inner end wall of the part 46 and the wall of the casing 10 to terminate flush with the internal wall surface. The piston 48, in an extended position, extends into the interior of the valve casing 10 and is so located as to be capable of overlying the respective valve blade 32 on the downstream side thereof when the blade 32 is in the closed position (see the lower assembly in Fig. 2).The piston 48, in a retracted position, is withdrawn into the guide sleeve 50 and does not project beyond the internal wall surface of the casing 10, whereby the respective valve blade 32 is free to move to its open position (see the upper assembly in Fig. 2). Each time the blades 32 move to their closed positions, the pistons 48 are moved to their extended positions and relieve the pressure on the valve blades and actuators.

The use of an isolating damper valve as described enables the axial length of the casing 10 to be considerably reduced relative to the crosssectional area of the casing, for example 0.46 times the cross-sectional area, as the casing does not have to relate to the length of a single valve member in an open position. The use of a pair of pivotal valve blades 32 reduces the length of the effective valve member in the open condition and the blades 32 can extend beyond the downstream end of the casing 10 in the open condition, as they will simply then project into the internal space of the delivery conduit. Also the use of a pair of pivotal valve blades 32 in preference to a butterfly valve improves the sealing which can be achieved between the valve member and the casing.The use of the piston/cylinder assemblies 44 in association with the valve blades 32 can provide, in a simple but effective manner, a valve which, in its closed position, will withstand pressure created in the riffle area, for example in the case of fire, so as to isolate the riffle area as necessary.

Various modifications may be made without departing from the invention. For example the valve blades may be pivotally movable by any suitable means and may if desired be arranged to be manually controlled. The drive shafts if used may have individual drive means and may be driven by other than the arrangement described and shown. Further the blades may be locked in their closed position by suitable means other than the piston/cylinder assemblies.

Whilst endeavouring in the foregoing Specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to whether or not particular emphasis has been placed thereon.

Claims

1. Valve apparatus for use in an arrangement for transporting a pulverised coal/air mixture, the valve apparatus comprising a valve casing through which the material can flow, valve means having a pair of valve parts pivotally mounted in the casing to be movable between an open position wherein both valve parts extend substantially downstream of the direction of material flow, and a closed position wherein the valve parts extend transversely of the direction of material flow so as to prevent flow through the casing, and means provided to releasably lock the valve parts in the closed position.

2. Apparatus according to claim 1, wherein means for pivotally mounting the valve parts extend across the casing and have a guard associated therewith on the upstream side so as to protect the mounting means against the mixture passing through the casing.

3. Apparatus according to claim 2, wherein the guard is formed of a hard wearing material.

4. Apparatus according to claim 2 or 3, wherein the guard is of triangular configuration with the apex facing upstream in the direction of flow.

5. Apparatus according to any of the preceding claims, wherein the valve parts are mounted on respective rotatable members extending across the casing, a drive arrangement for the rotatable members being provided.

6. Apparatus according to claim 5, wherein the rotatable members are geared to rotate together and simultaneously move the valve parts.

7. Apparatus according to claim 5 or 6, wherein the rotatable members extend across a central part of the casing so that each valve part extends over substantially half the cross-sectional area of the casing in the closed position.

8. Apparatus according to any of claims 5 to 7, wherein the drive arrangement is power operated.

9. Apparatus according to any of claims 5 to 7, wherein the drive arrangement is manually operable.

10. Apparatus according to any of the preceding claims, wherein the casing has such a dimension in the flow direction that the valve parts project therefrom in the open position for entry into a conduit connectible downstream of the casing.

11. Apparatus according to any of the preceding claims, wherein the casing has internal valve seats for seating the valve parts in the closed position, and sealing means being associated with each valve seat.

12. apparatus according to any of the preceding claims, wherein the valve parts move through substantially 909 between the open and closed positions.

13. Apparatus according to any of the preceding claims, wherein an internal wall of the casing is profiled downstream of the valve parts to substantially correspond with the path of movement of free edges of the valve parts.

14. Apparatus according to any of the preceding claims, wherein the locking means comprises a piston/cylinder assembly which is associated with each valve part and wherein a piston can project internally of the casing when the respective valve part is in the closed position, so as to overlie the valve part on a downstream side thereof.

1 5. Valve apparatus substantially as hereinbefore described with reference to the accompanying drawings.

1 6. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.