GB2477601A

GB2477601A - Flap valve

Info

Publication number: GB2477601A
Application number: GB201022020A
Authority: GB
Inventors: David Norris; Stephen Manson
Original assignee: DC Norris and Co Engineering Ltd
Current assignee: DC Norris and Co Engineering Ltd
Priority date: 2010-02-03
Filing date: 2010-12-23
Publication date: 2011-08-10
Anticipated expiration: 2030-12-23
Also published as: GB201022020D0; GB201001757D0; GB2477601B

Abstract

A flap valve 30 includes a core assembled from a stack of discs 36, 38, 40, secured together by screws 50 and having therein openings (42, Fig. 1) which cooperate to form a pair of ducts through the core. The disc 38 is formed with recesses to retain projections (56, Fig. 4) on valve members 54 which are pivotable between a position in which the ducts through the core are open and a position in which the ducts are closed. The valve may be used as a non-return valve in a system for cooling food products and which incorporates pipework through which cooling water is made to flow.

Description

FLAP VALVE

This invention relates to a flap valve of simple and inexpensive construction which is suitable for use as a non-return valve for controlling the flow of water used as a coolant in food processing systems, but which has other uses.

According to one aspect of the invention, a flap valve comprises a housing bounding a passageway within which is disposed a core assembled from a stack of superimposed discs, the discs having openings therein which communicate one with another so as to form a duct through the core, an intermediate one of said discs being provided with recesses for receiving projecting portions of a valve member, the projecting portions enabling the valve member to pivot between a position in which the valve member obstructs the duct and a position in which the duct is unobstructed, the projecting portions of the intermediate valve member being retained in said recesses by cooperation therewith of adjacent discs.

The discs may each be formed with two segment shaped openings, so that two separate ducts extend through the valve core. Each of the discs may have an annular peripheral portion and a cross-piece which extends diametrically across the disc so as to separate the two openings one from another. The recesses may communicate with the openings and may take the form of indentations in the annular portion, the recesses being located adjacent the ends of the cross piece. One of the discs may have an annular portion which is wider (considered in a radial sense) than the annular portion of another of the discs so as to form a seat for the valve member. An endmost one of said discs may be secured to the housing, as by welding, and the remaining discs secured in place by screws which S are screwed into threaded bores in the cross piece of said endmost disc.

Alternatively, the discs may be held in place relative to the housing by providing the housing with an internal annular rib, and arranging the rims of two of the discs to grip the rib, the discs being braced relative to each other by a screw fastening.

According to another aspect of the invention, a flap valve includes a stack of three discs and means for securing the discs together, openings in the discs defining a duct through the stack, an intermediate one of said discs being provided with recesses which extend into the opening and receive projecting portions of a valve member, the projecting portions enabling the valve member to pivot relative to the stack and being retained in the recesses by a pair of discs disposed one on each side of the intermediate disc.

According to a further aspect of the invention, a flap valve includes a stack of three discs and means for securing the discs together, each of the discs having a pair of openings therein, the openings defining a pair of ducts through the stack, an intermediate one of said discs being provided with recesses which extend into the openings and receive projecting portions on a pair of valve members, the projecting portions enabling the valve member to pivot relative to the stack and being retained in the recesses by a pair of discs disposed one on each side of the intermediate disc.

The flap valve may be employed in a chilling installation for food products which comprises a chiller having a rotary drum arranged within a casing, an upwardly extending duct, an inlet into the duct from the chiller casing, and an outlet from the duct into an elevated holding tank.

S Upper and lower such flap valves may be disposed within the duct between said inlet and outlet, the lower valve having a fixed position and the upper valve being movable lengthwise of the duct.

In the drawings: Figure 1 is a plan view of the outlet side of a preferred embodiment of flap valve with the valve members shown in the positions they occupy when the valve is open, Figure 2 is a section through the valve taken on the line 11-Il in Figure 1, Figure 3 is a section through the valve taken on the line Ill-Ill in Figure 1, Figure 4 is a plan view of the valve member, Figure 5 is a plan view of the intermediate disc, Figure 6 is a plan view of the disc which forms the underside of the valve core, Figure 7 is a diagrammatic view of a chiller, holding tank and the duct interconnecting them, the duct being broken away to show the location of flap valves in accordance with the invention.

Referring to Figures 1 to 6 of the drawings, a flap valve 30 incorporates a housing 32 having a rim 34 which enables the valve to be fitted into a duct through which liquid, in particular water, may flow in one direction * only. The valve will be described as if disposed as shown in Figures 2 and 3, in which the edge of the housing provided with the rim 34 is to be regarded as' the upper side of the valve. With the valve so disposed, liquid may flow through the valve in the vertically upwards direction and will tend to move valve members 54 into their upstanding, open positions illustrated. The valve members 54 have a tendency to fall under their own weight or under a pressure differential so as to prevent return flow.

The housing 34 bounds a short cylindrical passageway in which is located a core assembled from a stack of three superimposed circular discs, namely disc 36 which forms the underside of the core, disc 40 which forms the upper side of the core, and disc 38 which is sandwiched between discs 36 and 40 and is referred to herein as the intermediate disc.

The discs making up the core are substantially identical iii shape, with minor differences as will be described below. Each disc may be cut from steel or aluminium alloy sheet and machined to form a pair of segment shaped openings 42 shown in Figures 5 and 6 in the case of discs 38 and 36, respectively. Following the creation of the openings 42, each disc consists of a principally annular peripheral portion 44 (referred to herein for convenience as being annular) and a diametrically extending cross-piece 46.

The disc 40 substantially corresponds in shape to disc 36 shown in Figure 6, except that the width of each of the segmental openings 42 of disc 36, measured perpendicularly to the cross-piece, is slightly less than that of disc 40, whereby the annular portion 44 of disc 36 is slightly wider than that of disc 40.

The intermediate disc 38 is dimepsionally identical to disc 40, but differs S from it in that it has a recess 52 cut into the annular portion 44 in each corner where the cross-piece adjoins the annular portion. When the discs are securedtogether to form the core, with the cross-pieces 46 in alignment, the openings 42 combine to form two ducts through the valve core.

The cross-piece of each disc is provided with a pair of bores 48 which align with one another when the discs are stacked together. The bores 48 of disc 36 are screw threaded. Disc 36 is welded or otherwise rigidly secured in place within the housing such that the exposed lower surface of disc 36 is flush with the underside of the housing. The remaining discs, namely the intermediate disc 38 and the uppermost disc 40, are secured to each other and to the lowest disc 36 by screws 50 which are screwed into the bores of disc 36, the screw heads bearing against the upper surface of the cross-piece of the uppermost disc 40.

During assembly of the core within the housing, two valve members 54, each as shown in Figure 4, are fitted into place so as to cover the openings 42. Each of the valve members corresponds in shape and dimensions to one of the openings 42 but has projecting projections in the form of nibs 56 which are received in the recesses 52. The nibs are held in place by the annular portions of discs 36 and 40. The nibs are supported on the inner rim of the annular portion 44 of the disc 36 and rotatable within the recesses 52. The valve members may thereby pivot between, on the one-hand, a valve-closed condition in which the curved edges of the valve members rest on a seat constituted by the inner rim of the annular portion 44 of disc 36 and, on the other hand, a valve-open condition in which the valve members extend upwards as shown in Figures 1 to 3 (the annular portiqn of disc 40 being so dimensioned that S pivoting movement of the valve members is not restrained).

Solely as an example, a flap valve in accordance with the invention and suitable for use in the system to be described herein with reference to Figure 7 incorporates discs 36, 38 and 40 cut from steel or aluminium * alloy sheet with a thickness of substantially 3mm as well as valve members cut from steel sheet with a thickness of substantially 1mm.

The disc 36 has an outer diameter of 47mm, the annular portion has an inner diameter of 37mm and hence a width considered radially of 5mm.

The cross-piece has a width of 7mm. Measured perpendicularly to the cross-piece at its widest point, each of the segment shaped openings has a width of 15mm.

Discs 38 and 40 each have an annular portion with an outer diameter of 47mm, an inner diameter of 39mm and therefore a width considered radially of 4mm. The cross-piece has a width of 7mm. Each segment shaped opening measures at its widest point 16mm perpendicularly to the length of the cross-piece.

At its widest point, perpendicularly to the length of its straight edge, each valve member measures 15mm, so that it is received within the segment shaped opening of discs 38 and 40 with a clearance of 1 mm, and will overlap the annular portion of disc 36 by 1 mm.

A valve having these dimensions has been found to function very satisfactorily, the seats formed by the edge of the annular portions of disc 36 providing adequate support for the curved edges of the valve members when they are in their closed pos,itions. A certain amount of leakage may S take place past the valve when it is closed, but this is acceptable when the valve is performing a function such as that to be described with reference to Figure 7; The valve described above is not limited to use in the system referred to above but may be of use as a non-return valve in other situations.

The flap valve has been described as having three superimposed discs, the intermediate one of which is provided with recesses for receiving the pivots on the valve members. However, it lies within the scope of the invention for there to be more than three discs, particularly if they are cut from thinner material than referred to above. In this connection, the recesses 52 may be arranged to extend through more than one disc, and/or more than one disc may be provided on one or both sides of the intermediate disc or discs. To maximise flow, the preferred valve design is provided with two ducts constituted by the openings 42. However, it lies within the scope of the invention for there to be but one duct, the cross-pieces being displaced to one side so as to accommodate a single but wider valve member. The discs may be secured together by means other than screws. Instead of welding the disc 36 to the housing 32 it may be secured by other means. For example, the housing may be provided with an internal, circumferentially extending rib, which is clamped between a pair of discs, the structure being braced by screwing the discs together. In another possible alternative, the housing may be internally screw-threaded and one or more of the discs externally screw-threaded in order to secure the discs in place. In any event, a disc other than the disc 36 may be secured to the housing and provided with scre-threaded bores to enable the other discs to be secured thereto.

Conveniently the nibs are formed in one piece with the valve members but it falls within the scope of thç invention for the projecting portions to S be separate from the valve members and secured into place. Thus, for example, a welded-on strip may extend along the straight edge of each valve member.

Referring to Figure 7, an installation for processing food products in which valves in accordance with the invention may be employed includes a chiller 102 having a casing 104 within which a drum (not shown) is rotatable. The chiller may be constructed and operate in accordance with patent specification No GB 2 419 396. The drum has a perforated peripheral wall so that a quantity of water contained in the casing may flow through the drum so as to cool bags of food product tumbled therein, the water being conducted to a system for cooling the water, either within the housing or at a remote location. The water may be maintained at a temperature of about zero degrees Celsius so as to cool the bags to a temperature of about four degrees Celsius. The bags are introduced into the chiller through an opening at the right-hand side of Figure 7, and are removed through the same opening after all or most of the water has been removed from within the casing 104. The chiller is inclined downwards towards the rear (i.e. the left hand side of Figure 7) so as to maximise the quantity of water which may be contained within it. Conventionally, a drain pipe 106 is connected to the casing at its lowest point to enable the chiller to be drained; flow through the pipe being controlled by a valve 107.

A holding tank 108 is mounted at an elevated level, preferably immediately above the chiller as shown, or alternatively on a gantry.

Because the chiller is inclined towards the rear, the floor of the holding tank slants downwards towards the rear. A generally upwardly extending duct 110 is arranged at the rear of the installation, the lower end of the duct 110 opening into the pipe 106 upstream of the valve 107, or being connected to the pipe 106 in some other way. A three-way valve 112 is provided at the junction between pipe 6 and duct 10, whereby water draining from the chiller may flow to waste through the pipe 106 or be diverted into the duct 110. At its upper end the duct 110 is connected to an outlet pipe 114, which opens into the holding tank. An outlet 116 opens from the lowest part of the holding tank into the chiller and is provided with a three-way valve to enable water to drain from the holding tank into the chiller or be diverted into a drain pipe 118. The holding tank may also be provided with an overflow pipe, not shown.

A lower non-return valve 30A is arranged at a fixed position within the duct 110 in the vicinity of the junction between the duct and pipe 106.

An upper non-return valve 30B is arranged within the duct 110 and is coupled to a rod 124 which may be extended or retracted by a piston and cylinder unit 112 so that the valve 30B may be reciprocated within the duct 110. Each of the valves 30A and 30B is arranged to open in response to excess water pressure in the duct below the valve, and therefore close in response to excess water pressure in the duct above the valve, or when there is no water in the duct.

Provided that the water in the chiller remains unpolluted and usable following the completion of a cooling cycle, the three-way valve 112 is positioned so as to admit water from the chiller into duct 110. The inherent pressure in the body of water acting on the underside of the non-return valve 30A moves that valve into its open position so that water flows through that valve and into the space between valves 30A and 30B.

Cylinder 126 is brought into operation and by way of rod 124 begins to reciprocate valve 30W As valve, 30B descends, valve 30A is made to S close and the body of water between the two valves causes valve 30B to open, water flowing upwards through the valve 30B and into the space above it. Subsequently cylinder 126 is retracted upwards, and the water above valve 30B causes that valve to close, and the body of water above it to be lifted into the holding tank. A suction effect is produced in the duct 110 below valve 30B, causing valve 30A to open, and more water to be drawn through it from within the chiller. The system continues to operate and transfer water into the holding tank as the valve 30B is reciprocated by cylinder 126, until the chiller has been substantially drained of water. It will be appreciated that valve 30A prevents water being forced back into the chiller as valve 3 OB descends. An advantage of the pumping system described above is that no damage is caused to the system if and when it runs dry, which would not be the case if the system made use of a centrifugal pump.

Alternatively, in the event that the water in the chiller has been polluted, by, for example, a bag being ruptured, the valve 107 is opened and the three-way valve 112 positioned to allow water in the chiller to drain away through pipe 106.

The chilled bags can be removed from the chiller after all of the water in the chiller has been transferred into the holding tank. When all of the bags have been removed from the chiller, outlet 106 is opened to allow water from the holding tank to refill the chiller. It will be appreciated that the temperature of the water in the holding tank will not have decreased significantly during the time which elapses between two successive cycles so that the chiller will be refilled with water which is at substantially the desired operating temperature and requires the expenditure of less power to cool it, than would otherwise be the case.

Although the system has been described as making use of a single movable valve 30B and a single fixed valve 30A, it is possible for there to be more than one fixed non-return valve and/or more than one movable non-return valve arranged in the duct 110 with a head to engage the underside of disc 36. The movable valve 30B shown in Figure 7 may have the same construction as that described above, but with a bore extending through the centre of the cross-pieces so as to receive the rod 124 extending from cylinder 126.

It will be observed that, when made fast with the housing 32, the disc 36 constitutes a base for the housing. It will be understood that by extension the casing may incorporate a base which is fast or integral with the housing, and such an arrangement (which would correspond in appearance to the valve shown in the drawings but with the part marked 36 being shown as part of the housing) is to be understood to fall within the scope of the invention. Accordingly a further aspect of the invention provides a flap valve comprising a housing having a base, first and second discs contained within the housing, the first disc being disposed between the base and the second disc, means for securing the discs to the base, openings in the base and the discs cooperating to defme a duct, the second disc being provided with recesses which extend into the opening and receive projecting portions of a valve member, the projecting portions enabling the valve member to pivot, and being retained in the recesses by the first disc and the base.

Claims

ULAIM:-S1. A flap valve, comprising a housing bounding a passageway within which is disposed a core assembled from a stack of superimposed discs, the discs having openings therein which communicate one with another so as to form a duct through the core, an intermediate one of said discs bemg provided with recesses tor receiving projecting portions ot a valve member, the projecting portions enabling the valve member to pivot with respect to the recesses between a position in which the valve member obstructs the duct and a position in which the duct is unobstructed, the projecting portions of the intermediate valve member being retained in said recesses by means of adjacent discs.
2. A flap valve as claimed m claim 1, wherein the discs are each provided with two segment shaped openings, whereby two separate ducts extend through the valve core.
3. A flap valve as claimed in claim 2, wherein each of the discs has an annular peripheral portion and a cross-piece which extends diametrically across the disc so as to separate the two openings one from another.
4. A flap valve as claimed in claim 3, wherein the recesses take the fOrm of indentations in the annular portion of the intermediate disc, the recesses being located adjacent the ends of the cross piece and communicating with the openings in the intermediate disc.
5. A flap valve as claimed in claim 4, wherein a second disc has an annular portion which is wider (considered in a radial sense) than the annular portion of' a third disc so as to fOrm a seat fOr the valve member.o. . iiap vaive as ciaimea in any preceaing claim, wnerein an enamost one of said discs is secured fixedly to the housing and the remaining discs are securea to tne saia enamost aisc oy screws receivea in inreauca Dores in the cross piece of said endmost disc./. A itap vaive as ciaimea in any or ciaims I to D, wnerein tne aiscs are held in place relative to an annular rib extending around the internal suriace 01 me nousmg, me rims oi two oi tile aiscs teing tracea relative to each other so as to grip the rib by a screw or bolt fastening.. A iiap valve wnicn inciuaes a stack or tnree uiscs and means br securing the discs together, openings in the discs defining a duct through tne stacK, an intermediate one 01 saia aiscs being provided witn recesses which extend into the opening and receive projecting portions of a valve member, tile projecting portions enabling tiie vaive member to pivot relative to the stack and being retained in the recesses by discs disposed one on eacn side or tile intermediate disc.9. A flap valve which mcludes a stacK or three diSCS and means br securing the discs together, each of the discs having therein a pair of openings which aeflne a pair or ducts through the stack, an intermediate one of said discs being provided with recesses which extend into the openings and receive projecting portions on a pair ot valve members, the projecting portions enabling the valve member to pivot relative to the stack and being retained in the recesses y discs disposed one on each side of the intermediate disc. Ii10. A chiller having a rotary drum arranged within a casing, an upwardly extending duct, an inlet into the duct from the chiller casing, and an outlet from the duct into an elevated holding tank, upper and lower flap valves as claimed in any preceding claim disposed within the duct between said inlet and outlet, the lower valve having a fixed position and the upper valve being movable lengthwise of the duct.11. A flap valve comprising a housing having a base, first and second discs housed within the housing, the first disc being disposed between the base and the second disc, means for securing the discs to the base, openings in the base and the discs defining a duct, the second disc being provided with recesses which extend into the opening and receive projecting portions of a valve member, the projecting portions enabling the valve member to pivot relative to the stack and being retained in the recesses by the first disc and the base.12. A valve substantially as hereinbefore described with reference to and as illustrated in the drawings.