Field of the Invention
The present invention is directed to slide valves utilized for controlling
high temperature and high velocity flow.
Cross-Reference to Related Application
The present application is a continuation-in-part of U.S. Application
Serial No. 09/007,666 filed January 15, 1998.
Background of the Invention
Slide valves utilized in controlling high temperature and high velocity
flow of products through the valve have a number of disadvantages--for example,
require seat plates and seat plate bolting, have seat plate distortion, and the
utilization of bolting that is under load due to differential pressure in the valves
and are only as strong as the bolting system strength of bolts resulting in seat
plate distortion, do not have a positive seal against by-pass from differential
pressure, do not allow for proper alignment of the orifice plate, and do not provide
for future expansion of the port opening.
Prior Art
The following patents represent the current state of the art with
respect to slide valves.
Treichel et al., U.S. Patent No. 5,301,712, discloses background information
concerning slide valves, their applications, problems and the like of slide valves
in the field of use of the present invention to which reference is made. It also
discloses a slide valve assembly including an orifice and a slide valve slidable
in the guides of the orifice plate assembly. The orifice plate assembly is slidable
into and out of position in the slide valve housing through a side opening via grooves
formed in the inner walls of the housing.
Houston et al., U.S. Patent No. 5,123,440, discloses a slide valve
for use in high temperature environments. The mounting ring of the slide valve is
propped against the bed plate by a plurality of columns which are adjustable by
screws connecting gussets to rails upon which the slide or disc slides.
Wiese, U.S. Patent No. 5,096,099, discloses a slide valve with an
adjustable cover that is connected at an opening to a container by a plurality of
socket head screws.
Owens et al., U.S. Patent No. 5,082,247, discloses a split seat gate
valve located within a length of pipeline. The valve is disposed between flanged
openings in the pipeline and is secured by a plurality of bolts.
Jandrasi, U.S. Patent No. 4,693,452, discloses several embodiments
of slide valves for high corrosive environments. In the most relevant embodiments,
the orifice plate and guide rails of the slide valve are attached to the valve housing
by a plurality of bolts that run parallel to the flow direction to connect the valve
assembly.
Purvis, U.S. Patent No. 4612,955, discloses an edge wear tab used
to prevent corrosion around the orifice in high temperature applications. Slides
are slidably mounted in rails which are bolted to the valve housing.
Graf et al., US Patent No 4,542,453, discloses a slide valve for high
temperature gas lines. The internals are removed only by disassembly of the valve
housing.
Jandrasi, et al., US Patent No 4,531,539, discloses a slide valve.
The orifice plate of the slide valve is releasably secured in place by bolts running
parallel to flow direction.
Jandrasi et al., US Patent No 4,512,363, discloses a valve assembly
wherein the valve internals (orifice assembly, valve seat, guides and slide) are
removably secured to the valve body by a clamping action. The clamping action is
established by a valve liner which engages the orifice assembly and presses it into
abutment with the valve body. A lower flange of the liner is removably positioned
between the slide valve body and outlet member.
Jandrasi et al., US Patent No 4,458,879, discloses a valve wherein
the valve internals are held in position by a clamping action of a quick make-up
cylinder. The orifice plate with guides for the slide is clamped to the valve body
by a quick connect cylinder that screws into the valve body.
Worley et al., US Patent No 4,253,487, discloses a slide valve using
a pair of opposing discs to control fluid flow through the valve. The guide rails
within which the discs slide are held in place by bolts that run parallel to the
flow direction.
Jandrasi et al., US Patent No 3964507 disclosed a slide valve having
removable internal components assembly comprising an orifice plate, guide and guide
support.
It would be advantageous to provide a slide valve which eliminates
bolting that is under load to differential pressures in the valve, which is much
stronger than a bolted system for maintaining the internals in position, which has
positive sealing against by-pass from differential pressure, in which no seat plate
is utilized thereby eliminating distortion from a seat plate, allows for future
expansion of the port, is easier to remove and replace internals rather than one
utilizing bolts which often gall, break, or are difficult to remove and replace,
in which the internals are maintained properly aligned, and which may be used for
all size valves.
According to the present invention there is provided an improved slide
valve for control of flow therethrough comprising, a body having a valve chamber
with an upstream entrance area and a downstream outlet area, an orifice plate provided
with an orifice, a circumferentially extending stub welded to the orifice plate
extending upwardly around the orifice, a guide assembly having a guide plate with
an orifice in alignment with the orifice of the orifice plate secured to the orifice
plate, the guide assembly having inwardly extending guides, a valve slide having
outwardly extending slides disposed in the inwardly extending guides, characterised
in that there is provided a support cone having an entrance chamber connected to
the body extending to adjacent the upstream entrance of the valve chamber and having
a downstream end area extending generally parallel to flow through the body, in
that the stub is welded adjacent to an internal end of the support cone, and in
that the orifice plate, guide assembly, and the slide valve can be released as a
unit by cutting the weld connection of the stub to the internal end of the support
cone and withdrawn through a bonnet, and replaced through the bonnet and welding
the remaining upper end of the stub to the lower end of the support cone.
Preferred embodiments are set out in the sub-claims.
The present invention is directed to a slide valve in which product
flow is controlled through the valve. The internals of the slide valve comprise
the orifice plate with a circumferentially-extending stub welded to it, and the
guide assembly for the slide or disc, the orifice plate circumferential stub being
connected by a weld assembly to an internal support cone which in turn is welded
to the valve body. Preferably the orifice plate and the guide assembly are welded
together into a monolithic or unitary structure, or the guide assembly is supported
by the orifice plate by wrap around guides bolted or pinned to the orifice plate
without the bolts or pins bearing any load. The internals, guide assembly, and orifice
plate may be removed quickly and easily by cutting a welded connection of the weld
assembly to the stubs and replaced by rewelding the stub connection to the support
cone. The circumferentially extending stub can be welded either to the inside or
outside of the internal end of the support cone. This permits high temperatures
(538°C, 1,000°F+) and high pressure (3,45x105 Pa, 50 psi+) transfer of
product through the valve assembly having the above advantages and features. Further
details and aspects of the slide valve of the present invention are set forth in
the following description of preferred embodiments.
Preferred objects of the present invention are:
- to provide such a slide valve which eliminates bolting under load subject to
differential pressure in the valve.
- to provide such a slide valve which is stronger than slide valves using a bolted
system to maintain the internals in place in the valve.
- to provide such a slide valve which provides a positive seal against by-pass
from differential pressure.
- to provide such a slide valve which eliminates a seat plate and seat plate bolting
and hence has no seat plate distortion.
- to use stubs welded to the orifice plate and support cone which allows proper
alignment of the port or orifice in the orifice plate.
- to provide a slide valve in which the orifice plate and the valve slide are
a unitary or monolithic structure.
- to provide such a slide valve in which the internals are easier to remove and
replace than in current slide valves.
Ideally, in the present invention the internal parts are maintained
in proper alignment. In addition it is a preferred object of the present invention
to provide such a slide valve which may be utilized for all sizes of valves, which
is suited for large, small, and medium sized valves.
Other and further objects, features and advantages are set forth and
are inherent in the slide valve as set forth throughout the specification and claims.
Brief Description of the Drawings
- Figure 1 is a side elevational view in section of a slide valve of the present
invention,
- Figure 2 is a cross-sectional view looking in from the bonnet area of the orifice
plate and slide and guide assembly welded together into a monolithic or unitary
structure according to the invention, and
- Figure 3 is a cross-sectional view of a modification of the orifice plate and
slide and guide assembly according to the invention.
Description of the Preferred Embodiments
Referring to Figure 1, an improved slide valve 10 of the present invention
is illustrated, which includes the valve body 12 which has an upstream entrance
area 14 and the downstream outlet area 16. A support cone 18 having the entrance
area 20 is welded by the weld 21 to the valve body 12 adjacent its upstream entrance
area 14. An orifice plate 22 having the orifice or port 24 and a circumferentially
extending flange 26 is welded by the weld 21 to the cone 18.
The lower end of the support cone 18 has the flange 26 welded to it
to which the upper end of the circumferential stub 28 is welded by the weld 27 thereby
securing the orifice plate 22 to the lower end of the support cone 18.
Referring to Figure 2, combined by welding to the orifice plate 22
is a guide assembly 30 providing the inwardly facing recess 32 formed by the inwardly
facing projection 34 and the orifice plate 22, the projection 34 coacting with the
orifice plate 22 to provide the groove 32 which serve as guides for the slide 35
on the slide valve assembly 38. Thus, the guide assembly 30 and the orifice plate
22 are welded together by the weld 42 into a unitary or monolithic structure.
The valve internals comprising the monolithic orifice plate 22 and
slide and guide assembly 30 are supported in position in the valve body by means
of welding the upper portion of the circumferential stub 28 to the lower flange
portion 26 of the support cone 18 by the weld 27. Thus, the valve internals may
be removed from the slide valve body 12 simply by cutting the weld 27 at the top
of the circumferential stub 28 and removing them through the bonnet 46 (Figure 1),
and then can be replaced by reinserting the valve internals, the unitary orifice
plate 22 and guide assembly 30, into the valve body 12 through the bonnet 46 (Figure
1) and rewelding the top of the circumferential stub 28 to the lower connection
portion or flange 26 of the support cone 18. Preferably, the circumferential stub
28 is made tall enough so that the weld 27 at the top of the stub 28 may be cut
a number of times - for example, four times and replaced and rewelded each of these
times.
In operation and referring again to Figure 1, the slide valve assembly
38 or disc is reciprocated by an actuator rod 44 which sealingly extends through
the bonnet 46. The actuator rod can be actuated by any suitable means, not shown,
and has a suitable stuffing box or sealing arrangement 47 for the actuator rod 44
which are conventional in valves of this type; and, accordingly, no description
thereof is given or deemed necessary.
Referring now to Figure 3, a modification is shown to the valve slide
assembly where like parts to those of Figure 2 are designated by the same reference
numerals with the letter "a" added.
The upper portion of the valve guide assembly 30a has the inwardly-extending
projection 36 which is supported on the outer recessed portions 37 of the orifice
plate 32a and held in position by the threaded bolts or pins 39. Thus, the guide
assembly 30a is supported and held in place by the wrap around projections 34a and
36 and are held in position by bolts or pins 39 which are not under load. The remaining
parts and functions of the modification of Figure 3 are the same as that of Figure
2, and no further description thereof is deemed necessary or given.
The valve body 12 is lined with refractory material 48 when used at
high temperature. Any refractory material having sufficient strength can be used
for the liner and is available from a number of suppliers, including Harbison Walker
(Pittsburg, Pennsylvania), National Refractories (Oakland, California), Norton Co.
(Worchester, Massachusetts), The Carborundum Co. (Niagara Falls, New York), Resco
Products, Inc. (Morristown, Pennsylvania), Plibrico (Chicago, Illinois), and A P
Green (Mexico, Missouri). Any such refractory material having a modulus of rupture
(MOR) over about 82,74x105 Pa (1200 psi) at normal operating temperatures
(about 96,52x105 Pa, 1400 to about 1,31x105 Pa 1900 psi is
preferred) is suitable for use in the present invention; and many commercially available
composites can either be modified by adding alumina and/or zirconia to increase
MOR or by varying such parameters as aggregate size, cooling rate, pressure, percentable
solids, vibration frequency, all as are known in the art, to maximize the strength
thereof for use in accordance with the present invention.
Accordingly, the present invention is well suited and adapted to attain
the objects and ends and has the advantages and features mentioned as well as others
inherent therein.
While presently preferred embodiments of the invention have been given
for the purpose of disclosure, changes can be made therein and other uses thereof
can be made which are within the scope of the appended claims.