U.S. patent application number 11/832776 was filed with the patent office on 2009-02-05 for check valve.
Invention is credited to Sean Morgan, Stuart Morgan.
Application Number | 20090032619 11/832776 |
Document ID | / |
Family ID | 40337189 |
Filed Date | 2009-02-05 |
United States Patent
Application |
20090032619 |
Kind Code |
A1 |
Morgan; Stuart ; et
al. |
February 5, 2009 |
CHECK VALVE
Abstract
A check valve which includes a body adapted at one end to
receive a liquid source and at the other end to engage with a spray
nozzle and having a bore therethrough, an internal annular recess
within the body, the upstream end of which body provides a valve
seat, a valve assembly located in the recess and having a valve
member having a generally curved end directed towards the seat and
bias means to normally hold the member against the seat until the
pressure at the inlet reaches a predetermined minimum.
Inventors: |
Morgan; Stuart; (Cheltenham,
AU) ; Morgan; Sean; (Cheltenham, AU) |
Correspondence
Address: |
EDWIN D. SCHINDLER
FIVE HIRSCH AVENUE, P.O. BOX 966
CORAM
NY
11727-0966
US
|
Family ID: |
40337189 |
Appl. No.: |
11/832776 |
Filed: |
August 2, 2007 |
Current U.S.
Class: |
239/533.1 ;
239/569 |
Current CPC
Class: |
Y10T 137/7904 20150401;
B05B 1/3006 20130101; Y10T 137/7837 20150401; F16K 15/026 20130101;
B05B 12/08 20130101 |
Class at
Publication: |
239/533.1 ;
239/569 |
International
Class: |
B05B 1/34 20060101
B05B001/34; B05B 1/30 20060101 B05B001/30 |
Claims
1. A check valve in a spray nozzle assembly, comprising: a body
having an upstream end for receiving a liquid source and a
downstream end for engaging a spray nozzle with bore running
through said body from said upstream end to said downstream end; a
first component adjacent said upstream end of said body; a second
component adjacent said downstream end of said body, said first
component having a smaller diameter than a diameter of said second
component; a valve seat at a junction of said first component and
said second component; a valve assembly located substantially in
said second component and having a valve member with a curved end
directed towards said valve seat; and, biasing means for holding
said valve member against said valve seat until pressure at an
inlet of said valve member attains a predetermined minimum
pressure.
2. The check valve in a spray nozzle assembly according to claim 1,
wherein said curved end of said valve member is substantially
hemispherical in shape.
3. The check valve in a spray nozzle assembly according to claim 1,
wherein said curved end of said valve member is substantially
conical in shape.
4. The check valve in a spray nozzle assembly according to claim 1,
wherein said curved end of said valve member is made of a
sacrificial material and forms a valve seal with said valve seat
when said valve assembly is in a closed position.
5. The check valve in a spray nozzle assembly according to claim 4,
wherein said valve seat is shaped as a truncated cone.
6. The check valve in a spray nozzle assembly according to claim 1,
wherein said valve includes guide means for locating said valve
member axially within the bore for permitting liquid to flow around
said valve member when said valve assembly is in an open
position.
7. The check valve in a spray nozzle assembly according to claim 6,
wherein said guide means is positioned upstream of, and adjacent
to, the curved end of said valve member.
8. The check valve in a spray nozzle assembly according to claim 7,
wherein said guide means includes a plurality of arm members
extending between an axial component of said guide means to about a
surface of said first component, so that fluid flow over said guide
means is minimally obstructed.
9. The check valve in a spray nozzle assembly according to claim 1,
wherein said biasing means is a spring.
10. The check valve in a spray nozzle assembly according to claim
9, wherein said curved end of said valve member forms a valve seal
with said valve seat when said valve assembly is in a closed
position, said valve seal being connectable to said spring via a
screw.
11. The check valve in a spray nozzle assembly according to claim 1
further comprising releasable retaining means for retaining said
valve assembly within said body for providing a unitary check
valve.
12. The check valve in a spray nozzle assembly according to claim
11, wherein said releasable retaining means is a perforated sleeve
passing over said biasing means and retaining said biasing means in
a compression state when not released.
13. The check valve in a spray nozzle assembly according to claim
11, wherein said releasable retaining means is bayonet
fittings.
14. The check valve in a spray nozzle assembly according to claim
13, wherein said biasing means is a spring cage and said bayonet
fittings comprise lugs on said spring cage for engaging with
bayonet slots in an interior of said body, said bayonet slots
having sloping, or ramping, side walls.
15. The check valve in a spray nozzle assembly according to claim
1, wherein fluid flows through said check valve in a substantially
axial direction to the spray nozzle.
16. The check valve in a spray nozzle assembly according to claim
1, further comprising at least one air passage passing through said
body for entraining air into a fluid flow at said downstream end of
said body when fluid is flowing through said body.
17. The check valve in a spray nozzle assembly according to claim
1, wherein said valve seat is a removable, replaceable wear device
having a push-fit construction.
18. The check valve in a spray nozzle assembly according to claim
1, wherein said valve seat is used with a coaxial O-ring.
Description
AREA OF THE INVENTION
[0001] This invention relates to a check valve which is
specifically adapted to be used with spray drying nozzles, but
could also be used in association with other nozzles.
BACKGROUND TO THE INVENTION
[0002] For ease of description, we shall refer to the valve when
associated with spray drying of milk.
[0003] Spray drying techniques are well known and in these milk is
sprayed through nozzles into a chamber where the liquid part of the
milk is evaporated away and milk powder either falls to the floor
of the chamber and is removed therefrom.
[0004] Historically, on completion of operation the spray drying
industry simply stopped pumping the liquid through the nozzles and
as the pressure dropped, a certain percentage of the liquid simply
fell as drops from the nozzles, without being atomized, and this
material could well lead to pollution of the product in the
chamber.
[0005] Check valves have been proposed but in practice have
suffered from major disadvantages.
[0006] A first such disadvantage is that the valves caused a
limitation in liquid flow therethrough and there was a large
pressure drop over the valve. This meant that in order to operate a
plant to capacity, it was either necessary to use higher pressures
or larger diameter pipes and valves to enable the optimum flow
through the nozzles.
[0007] The second disadvantage was that these valves normally had a
soft seal, such as an O-ring and it was found, in practice, that
this seal could be destroyed during use which would enable parts of
the O-ring to pass to the chamber, again polluting the product.
[0008] In fact most of these check valves have had a complex design
which requires the use of many seals and multiple sealing points.
As a result there are many stagnant points such that milk products
can build up and, if overheated, catch fire. Additionally soft
seals are prone to failure and consequent leakage. As such check
valves are generally welded together any repairs are extremely
difficult.
[0009] Other check valves have used metal to metal seals which
increases the wear rate and as discussed above access for repair is
difficult in conventional valves.
[0010] An additional disadvantage with previous check valves is
that as fluid flow is not necessarily smooth through them and
stagnant deposits can form they are difficult to keep clean.
OUTLINE OF THE INVENTION
[0011] An object of the invention is to provide a check valve for
spray drying nozzles, and other nozzles, which causes little
restriction in the flow through the nozzle but which, at the same
time, does not have any parts which are likely to be passed into
the fluid stream.
[0012] A further object of the invention is to provide such a check
valve which can remain in situ while the system is cleaned and
which can also permit interchange of nozzles without the valve
itself being disturbed. Another object of the invention is to
provide such a valve which is easily cleaned.
[0013] The invention is a check valve in a spray nozzle assembly
which includes a body adapted at one end to receive a liquid source
and at the other end to engage with a spray nozzle and having a
bore therethrough, said bore having a first component adjacent the
upstream end of the body said first component having a smaller
diameter than a second downstream component such that a valve seat
is provided at the junction of these components, a valve assembly
located generally in the second component and having a valve member
having a generally curved end directed towards the seat and bias
means to normally hold the member against the seat until the
pressure at the inlet reaches a predetermined minimum.
[0014] It is preferred that the curved end of the valve member be
either generally hemispherical or conical in shape.
[0015] It is also preferred that the curved end of the valve member
be manufactured from some sacrificial material and that this end
form a seal with the valve seat when the valve is closed.
[0016] It may also be preferred that the valve seat be a removable
and replaceable component.
[0017] It may further be preferred that the valve seat be provided
with an O ring seal to the body to prevent any leakage during the
sealing phase.
[0018] It is further preferred that the valve member be provided
with guide means to locate it axially within the annular recess
such that liquid can flow around the valve member when the valve is
in its open position and that this guide means preferably be
adjacent the curved end of the valve member.
[0019] It is further preferred that this guide means have a
plurality of arms extending from an axial portion to the sides of
the first bore component such that fluid flow is relatively
unimpeded over it.
[0020] It is also preferred that the bias means be a spring and
that engagement between the valve and spray nozzle is effected
using bayonet fittings or screw means.
[0021] It is preferred that the spring be housed in a "spring cage"
which both houses and guides the spring along its axial travel. It
is further preferred that in order to facilitate flow past the
spring valve when it is unseated the cage is provided with
apertures through it along its length and around its diameter.
[0022] As previously stated it is preferred that a bayonet type
retaining means locates the cage within the valve body.
[0023] It is further preferred that the receiving bayonet type slot
for the body to receive the cage lugs have ramped or sloped side
walls to facilitate cage insert removal and the escape of dried
product.
[0024] It is also preferred that the cage be adapted to be used
with a large range of spring types and a large range of sealing
membranes.
[0025] In order that the invention may be more readily understood
we shall describe by way of non limiting example one particular
embodiment of the invention with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0026] FIG. 1 shows the check valve connected to an associated
spray nozzle;
[0027] FIG. 2 shows an exploded diagram of the assembly shown in
FIG. 1;
[0028] FIG. 3 shows a cross section through the body of the
valve;
[0029] FIG. 4 shows a sectional view of a check valve associated
with an air atomising nozzle;
[0030] FIG. 5 Shows a perspective view of a valve member and spring
assembly;
[0031] FIG. 6 Shows perspective views of the bayonet fitting
receptors in the valve body and the cage with lugs to cooperate
with the receptors;
[0032] FIG. 7 Shows a diagrammatic representation of a valve body
having a threaded spring guide and crown assembly and the press fit
seat with O ring seal to the body.
DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
[0033] The check valve body 10 can be considered to be generally
cylindrical with a central bore 11 and may be made of any metal
suitable for the purpose to which it is to be put.
[0034] At the upstream end 12, the bore is adapted to be connected
to a supply pipe for the liquid passing through the nozzle, in this
case, this will be considered to be milk.
[0035] Suitable sealing means may be provided between the pipe and
the valve body which could include an O-ring or the like in an
annular groove in either the body, the pipe end or both.
[0036] In this embodiment of the invention the other end of the
body 14 is threaded 15 to engage with a nozzle body 20 having a
corresponding screw thread arrangement. The nozzle body 20 is
adapted to receive an orifice disc which causes the atomisation of
the milk as it passes therethrough.
[0037] In another embodiment of the invention the end 14 of the
body 10 may have a bayonet type fitting over which a nozzle body
having a corresponding bayonet arrangement is fitted. The precise
form of connection not being restricted in the invention and it is
to be understood that any preferred engagement means may be
used.
[0038] The screw fitting enables ready disassembly of the nozzle
for cleaning and/or maintenance and, as will be seen from the
description hereafter, without disturbing the check valve.
[0039] The central bore 11 located in the valve body has two
components namely a first annular bore 16 and, partway along the
length thereof, a second annular bore 17 having a larger diameter
than that of bore 16.
[0040] The junction between bores 16 and 17 body provides a valve
seat 18 which as shown in FIG. 3 slopes towards the smaller bore
16.
[0041] A valve assembly 30 as shown in FIG. 2 has a valve member 31
on the upstream side thereof and which has a diameter smaller than
the diameter of bore 17 and this has a portion 35 directed towards
the nozzle with which a spring 32 may be associated which spring
can abut a further annulus adjacent the downstream end of the
nozzle and act against an annular portion of the valve assembly so
as to normally bias the valve member 31 towards the valve seat
18.
[0042] In this preferred embodiment of the invention the valve seal
and spring device are not unitary and are as shown in FIG. 5 where
the part of the valve which contacts the valve seat is also shown
to be generally hemispherical in shape.
[0043] The valve seat 18 is manufactured from a sacrificial
material and is a removable and replaceable component. The valve
seat is further provided with an O ring seal to the body to prevent
any leakage during the sealing phase.
[0044] In this embodiment of the invention the valve and spring
assembly are located in a perforated tube 40 which acts as the
spring retainer and which, in turn, can be fitted within the valve
body 10. The tube 40 acts to hold spring 32 in compression and is
provided with retaining means which is a bayonet fitting such that
the check valve assembly remains assembled when disconnected from
the spray nozzle. This arrangement causes the components of the
check valve to be housed in its body in an integral fashion such
that the spray nozzle can be serviced without interfering with the
check valve.
[0045] If access to the check valve is required it can be
disconnected from the spray nozzle and the retaining tube 40
released by releasing its bayonet fitting which in turn causes the
spring to no longer be in compression such that the valve member
assembly can be removed.
[0046] As shown in FIG. 6 the spring cage 40 has large lugs 41
which are adapted to engage in the slots 42 having ramped side
walls 43. This unique ramping facilitates easier cage insert
removal and at the same time, on disassembly, assists the exit of
any build up of dried product which has occurred.
[0047] In further embodiments of the invention other retaining
options of the cage design are provided. These include a full
length spring guide and crown assembly 13 as shown in FIG. 7 or
alternatively a cage insert of a similar design but exclusive of a
thread being a simple slip in design of similar diameter to the
receiving bore in the body exclusive of any retaining design other
than that of the carrier assembled over the top compressing it into
place. The crown providing the stop on the body end. This figure
also shows a press fit seat with O ring seal 19.
[0048] The valve member may be made of any required material but in
this embodiment of the invention it includes a metal body 31 and
metal generally triangular guide member 34 between a hemispheric
component 33 which is of a synthetic plastics material such as PTFE
or some other engineering grade plastic which can be machined or
moulded.
[0049] The guide member 34 consists of a plurality of arms,
preferably 3, which extend from a central portion to the sides of
bore 16 and therefore provide little obstruction to fluid flow. In
fact the pressure drop across the check valve is kept to a minimum
by the fluid path passing from the downstream end of the valve
member, through the perforations in the retaining means and through
the spring to be directed down the middle of the spray nozzle in a
straight path.
[0050] This component 33 seats in valve seat 18 when the valve is
closed when fluid pressure upon the valve member is reduced and is
of a sacrificial material compared with the metal valve seat 18. It
is also possible to replace the valve member without having to
machine the seat.
[0051] By use of a sacrificial material seated into a metal seat a
good seal can be maintained without the use of soft O-rings which
may otherwise break down and act as contaminants to the fluid being
sprayed.
[0052] The component 33 described here is generally hemispherical
and is adapted to seat in the truncatedly conical valve seat 18. In
another embodiment of the invention it may be preferred that this
valve component 33 be conical in form.
[0053] In operation, when there is no pressure in the milk line,
the valve member abuts the seat and provides a good seal
therebetween preventing any liquid in the line from passing through
the nozzle.
[0054] When the pressure in the line increases to a pressure which
would be sufficient for the nozzle to operate correctly, the valve
body is caused to move against the spring towards the nozzle. Guide
means 34 permits fluid flow past it and maintains the valve
assembly 30 coaxially within bore 11.
[0055] In this way the amount of restriction presented to the fluid
passing through the valve body is not great and the efficiency of
the nozzle is not degraded to a degree sufficiently substantial to
adversely effect the operation of the nozzle.
[0056] When the pressure in the line drops, the valve member moves
towards the upstream end until the valve contacts the seat and
further liquid is prevented from passing to the nozzle and thus to
the product being treated.
[0057] This means there is no likelihood of the product being
polluted by material which has a drop size very much greater than
the normal atomised drops from the nozzle from which the liquid
evaporates in the chamber.
[0058] Also the arrangement is such that the nozzle body can
readily be removed by operation screw fitting for cleaning or
replacement of the orifice disc without, in any way, adversely
effecting the check valve.
[0059] Also cleaning and maintenance can be effected with the check
valve in situ so the existence of this valve does not increase the
time taken for normal maintenance tasks.
[0060] Whilst we have, in this specification, described one
particular mechanical arrangement of the valve, it will be
understood that other forms, which operate in the same manner as
that described, can readily be utilised in the invention.
[0061] A further example of the check valve of the invention is
shown in FIG. 4 and shows the check valve of the invention when
used in association with an air atomising nozzle. The operation of
the valve is essentially the same as previously described however
air passages 70 are present in the assembly as shown and the air
aids in the break up of the fluid by air atomisation.
[0062] In addition it is to be understood that whilst the valve is
particularly useful in spray drying milk it can readily be used in
other applications where it is undesirable that product passes
through the nozzle other than under full pressure and being
atomised.
[0063] All such modifications and applications are deemed to be
within the spirit and scope of the invention.
* * * * *