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Patent 2405397 Summary

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(12) Patent: (11) CA 2405397
(54) English Title: STEAM PRESSURE REDUCING AND CONDITIONING SYSTEM
(54) French Title: SYSTEME DE REDUCTION ET DE CONDITIONNEMENT DE LA PRESSION DE LA VAPEUR
Status: Deemed expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • F16K 47/00 (2006.01)
  • F16K 49/00 (2006.01)
  • F22G 5/12 (2006.01)
(72) Inventors :
  • HIGUCHI, HIROYUKI (Japan)
(73) Owners :
  • DRESSER, INC. (United States of America)
(71) Applicants :
  • DRESSER, INC. (United States of America)
(74) Agent: KIRBY EADES GALE BAKER
(74) Associate agent:
(45) Issued: 2009-08-04
(22) Filed Date: 2002-09-27
(41) Open to Public Inspection: 2003-07-04
Examination requested: 2006-06-07
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
10/039,343 United States of America 2002-01-04

Abstracts

English Abstract

A steam conditioning system comprising a steam conditioning valve 1 for depressurizing and desuperheating steam S by supplying moisture W in the conditioning valve. A discharge pipe 3 connected to the steam conditioning valve 1 has a horizontal section 3a, and the horizontal arrangement section 3a is provided with a moisture drain 4 or at a portion near the bottom. Condensed moisture W1 is extracted from this moisture drain 4 and is recycled as moisture W to be supplied to the steam S in the conditioning valve 1. The steam conditioning valve 1 further has a reduced annular section 9 with a nozzle 5a disposed therein for injecting subcooled water mist W. A transport conduit 5 connects the drain 4 to nozzle 5a. Moisture W is drawn into steam flow S due to the Venturi effect caused by the pressure drop through the reduced annular section 9.


French Abstract

Un système de conditionnement à la vapeur comprenant une soupape de conditionnement à la vapeur 1 pour dépressuriser et désurchauffer la vapeur S en fournissant de la vapeur d'eau W dans la soupape de conditionnement. Une conduite d'évacuation 3 raccordée à la soupape de conditionnement à la vapeur 1 possède une section horizontale 3a, et la section horizontale 3a est fournie avec un tuyau d'évacuation de la vapeur d'eau 4 ou à une partie près du fond. La vapeur d'eau condensée W1 est extraite de ce tuyau d'évacuation de la vapeur d'eau 4 et recyclée en vapeur d'eau W à fournir à la vapeur S dans la soupape de conditionnement 1. La soupape de conditionnement à la vapeur 1 possède en outre une section annulaire réduite 9 avec une buse 5a placée à l'intérieur pour injecter de l'eau atomisée sous-refroidie W. Un conduit de transport 5 raccorde le tuyau d'évacuation 4 à la buse 5a. La vapeur d'eau W est associée au débit de vapeur S à cause de l'effet Venturi dû à la chute de pression par la section annulaire réduite 9.

Claims

Note: Claims are shown in the official language in which they were submitted.




CLAIMS:


1. A steam conditioning system having:

a steam conditioning valve for depressurizing and
desuperheating superheated steam by supplying moisture thereto said
valve oriented wherein flow is discharged from the valve through a
lower discharge end of said valve in a downward substantially vertical
direction;

a discharge pipe connected to the lower discharge end of the
steam conditioning valve, the discharge pipe comprising:

a substantially horizontal section being provided with a moisture
drain in proximity to the bottom of the horizontal section;

a substantially vertical section between the lower discharge end
of the steam conditioning valve and the horizontal section;

a nozzle for injecting a water mist into the lower discharge end
of the steam conditioning valve wherein the nozzle has a discharge
opening exiting into an annular reduction in the longitudinal cross-
section of the lower discharge end of said valve; and

a conduit for connecting said nozzle to said moisture drain for
transporting condensed water to said nozzle, wherein moisture is
drawn from said moisture drain of the discharge pipe through the
transport conduit and out the nozzle discharge opening into the lower
discharge portion of the conditioning valve due to Venturi effect in the
annular reduction of the discharge portion of the valve.



7



2. A steam pressure reducing and conditioning system operable to be
connected between a steam source and a steam work section, the system
comprising:

a valve having an inlet and a lower discharge end, the inlet
receiving superheated steam from the steam source, said valve
oriented wherein flow is discharged from the valve through the lower
discharge end of said valve in a downward substantially vertical
direction, wherein a lower discharge portion of the valve includes a
reduced annular section and a discharge opening of a nozzle is
disposed in the reduced annular cross-section of the lower discharge
portion of the valve relative to the annular cross-section of the
discharge pipe;

a discharge pipe having a proximal end, a distal end, a
substantially vertical portion between the ends, and a substantially
horizontal portion between the vertical portion and the distal end, the
proximal end being connected to the lower discharge end of the valve
outlet and the distal end supplying steam to the steam work section;
and

a transport conduit connecting the horizontal portion of the
discharge pipe to the nozzle, whereby steam flowing through the
reduced annular section in the lower discharge portion of the valve will
flow faster than steam through the discharge pipe, and whereby
moisture is drawn through the transport conduit from the horizontal
portion of the discharge pipe into the valve and exits the discharge
opening in the nozzle due to reduced pressure of steam flowing
through the reduced annular section in the lower discharge portion of
the valve.


8



3. The system of claim 2, comprising a forced delivery apparatus
connected to the transport conduit for delivering moisture to the valve from
the
horizontal portion of the discharge pipe.


4. A method of operating a steam pressure reducing and conditioning
system, the method comprising:

providing a valve having an inlet and a lower discharge end, the
inlet receiving superheated steam from the steam source, said valve
oriented wherein flow is discharged from the valve through the lower
discharge end of said valve in a downward substantially vertical
direction, wherein a lower discharge portion of the valve includes a
reduced annular section and a discharge opening of a nozzle is
disposed in the reduced annular cross-section of the lower discharge
portion of the valve relative to the annular cross-section of the
discharge pipe;

providing a discharge pipe having a proximal end, a distal end, a
substantially vertical portion between the ends, and a substantially
horizontal portion between the vertical portion and the distal end, the
proximal end being connected to the lower discharge end of the valve
and the distal end supplying steam to the steam work section; and

providing a transport conduit connecting the horizontal portion of
the discharge pipe to the nozzle;

receiving in the inlet of the valve superheated steam;

cooling the superheated steam passing through the lower
discharge end of the valve, by the steps of:

collecting condensed moisture in the horizontal portion of the
discharge pipe;


9



removing at least a portion of the collected condensed moisture
from the horizontal portion of the discharge pipe due to a reduced
pressure in the reduced area in the lower discharge end of the valve
when steam is flowing through the lower discharge end of the valve
and out through the discharge pipe;

transporting the removed collected condensed moisture through
the transport conduit to the discharge opening of the nozzle due to a
reduced pressure in the reduced area in the lower discharge end of the
valve when steam is flowing through the lower discharge end of the
valve and out through the discharge pipe; and

injecting the removed collected condensed moisture through the
discharge opening of the nozzle into the lower discharge end of the
valve to cool the superheated steam passing therethrough.


5. The method of claim 4, wherein supplying the removed condensed
moisture to the superheated steam passing through the valve comprises
misting the superheated steam with the removed condensed moisture.


10

Description

Note: Descriptions are shown in the official language in which they were submitted.



CA 02405397 2002-09-27

STEAM PRESSURE REDUCING AND CONDITIONING SYSTEM
TECHNICAL FIELD OF THE INVENTION
The present invention concerns a steam pressure reducing and
conditioning system.

BACKGROUND OF THE INVENTION

Referring to Prior Art Figure 3, it has been known to have a steam
pressure reducing and conditioning system comprising a steam source 24 (such
as boiler) for generating superheated steam S, a pressure reducing and
conditioning valve 21 for depressurizing and desuperheating steam S generated
by this steam source 24, and a discharge pipe 23 connected to an outlet of
steam pressure reducing and conditioning valve 21, and connected to a steam
work section 22, downstream of valve 21.
As illustrated in Prior Art Figure 3, steam pressure and conditioning valve
21 receives superheated and pressurized steam S inflowing in inlet 21 a. Steam
S is desuperheated and depressurized by passing steam S valve 21 and
injecting subcooled water mist W (not shown) from one or more nozzles 25 in
the
lower portion of valve 21.
The desuperheated and depressurized steam S,, discharged from the
valve 21 and the subcooled water mist W injected in valve 21, flow into the
discharge pipe 23 and are conveyed to the steam work section 22. A portion of
discharge pipe 23 is arranged horizontally 23a. Some of the subcooled water
mist W condenses and clings to the discharge pipe at 23a and flows along the
bottom of the horizontal section. Steam S, flows past these areas of
condensation creating temperature differentials in the interior surface of the
pipe
23.
Consequently, the pipe 23 deforms (bends upward) and possibly breaks
due to expansion and stress due to the temperature difference in horizontal
section of pipe 23, and moreover, the condensed moisture Wl, flowing at the
bottom of the pipe 23 is enrolled up by the high speed flow of steam S,
(jumping
phenomenon). The jumping phenomenon erroneous temperature
1


CA 02405397 2008-08-27

measurements in temperature sensors in the pipe 23 for detecting the heat of
the steam S1.
It is an object of the present invention to provide a steam pressure
reducing and conditioning system that can solve the aforementioned
problems.
In one particular embodiment there is provided a steam conditioning
system having: a steam conditioning valve for depressurizing and
desuperheating superheated steam by supplying moisture thereto said valve
oriented wherein flow is discharged from the valve through a lower discharge
1() end of said valve in a downward substantially vertical direction; a
discharge
pipe connected to the lower discharge end of the steam conditioning valve,
the discharge pipe comprising: a substantially horizontal section being
provided with a moisture drain in proximity to the bottom of the horizontal
section; a substantially vertical section between the lower discharge end of
the steam conditioning valve and the horizontal section; a nozzle for
injecting
a water mist into the lower discharge end of the steam conditioning valve
wherein the nozzle has a discharge opening exiting into an annular reduction
in the longitudinal cross-section of the lower discharge end of said valve;
and
a conduit for connecting said nozzle to said moisture drain for transporting
condensed water to said nozzle, wherein moisture is drawn from said
moisture drain of the discharge pipe through the transport conduit and out the
nozzle discharge opening into the lower discharge portion of the conditioning
valve due to Venturi effect in the annular reduction of the discharge portion
of
the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed invention will be described with reference to the
accompanying drawings, which show important sample embodiments of the
invention and which are incorporated in the specification hereof by reference.
A
more complete understanding of the present invention may be had by
reference to the following Detailed Description when taken in conjunction with
the accompanying drawings, wherein:

2


CA 02405397 2008-08-27

Fig. 1 is a partial side view with schematic elements illustrating the
operation of the steam pressure reducing and conditioning system of the
present invention;

Fig. 2 is a partial cross-section view illustrating a portion of the
pressure reducing and conditioning valve used in the system of the present
invention of Fig. 1; and

Fig. 3 is a partial side view with schematic elements illustrating the
operation of a prior art steam pressure reducing and conditioning system.

SUMMARY OF THE INVENTION

Reference is now made to the Drawings wherein like reference characters
denote like or similar parts throughout the Figures.
The present invention concerns a steam pressure reducing and
conditioning system comprising a steam reducing and conditioning valve 1 for
desuperheating and depressurizing superheated steam S by injecting subcooled
water mist W in the lower portion of valve 1. A discharge pipe 3 is connected
at
its proximal end to the exit of valve 1. A steam work section 2 is connected
at the
distal end of pipe 3. The discharge pipe 3 has a horizontal portion 3a, and
said horizontal portion 3a is provided with a moisture drain 4 at the bottom
2a


CA 02405397 2002-09-27

portion or at a portion near the bottom of the horizontal portion 3a of pipe
3.
Condensed subcooled water mist ("moisture") W, is extracted from discharge
pipe 23 by drain 4 and is recycled and reinjected as moisture W to be supplied
to
the vapor S in said conditioning valve 1. Moisture drain 4 is connected by a
moisture transport conduit 5 to the conditioning valve 1.
The steam conditioning valve 1 further includes a reduced annular section
9 with a nozzle 5a disposed therein for injecting subcooled water mist W into
the
reduced annular section 9 of conditioning valve 1. Moisture W is drawn into
steam flow S due to the Venturi effect caused by the pressure drop through the
reduced annular section.

METHOD OF OPERATION
A superheated steam S is desuperheated by supplying subcooled water
mist ("moisture") W to steam conditioning valve 1. The desuperheated steam S,
flowing out from the conditioning valve 1 and the moisture W used for cooling
in
discharge valve 1 flows into discharge pipe 3, and is introduced in the steam
work section 2 connected to the downstream area of the discharge pipe 3.
In the present invention, when the moisture W discharged from the
conditioning valve 1 flows through the horizontal section 3a of the discharge
pipe
3, the condensed moisture W1 is drained from a moisture drain 4 disposed at
the
bottom portion 3a of this pipe 3, and the moisture W, extracted from the
moisture
drain 4 is recycled as part of moisture W to be supplied to the steam S in the
steam conditioning valve 1.
Consequently, moisture W, can be removed from the horizontal section
3a of the pipe 3, preventing the moisture W, from stagnating at the bottom of
the
pipe, solving the aforementioned problem of the prior art discussed in the
background section, and further, the recycling of moisture W1 used for cooling
the vapor S again in the conditioning valve 1 saves energy.

DETAILED DESCRIPTION
The attached drawings show an embodiment of the present invention,
which will be described below.

3


CA 02405397 2002-09-27

This embodiment of the present invention comprises, as shown in Figs. 1
and 2, a steam desuperheating and conditioning valve 1 wherein a superheated
and pressurized steam S generated in a steam generation source 8 (for
instance, boiler) flows into a first port 1 a of conditioning valve I. Steam S
is
desuperheated and depressurized by passing through a small hole section 6
(diffuser) having scattered small holes 6a, and the steam S, is discharged
from a
second port lb of conditioning valve 1. Steam S, is desuperheated by injecting
a subcooled water mist "moisture" W from one or more nozzles 7. A discharge
pipe 3 is connected at its proximal end to the exit of conditioning valve 1,
and at
its distal end to a steam work section 2 (for instance, condenser for a
nuclear
reactor).
Also, in this embodiment, the discharge pipe 3 is provided with a
horizontal section 3a extending from the conditioning valve 1 and disposed
horizontally with an elbow section 3b (bent section). The discharge pipe 3 is
so
composed that the condensed moisture W, flowing in this horizontal section 3a
is part of the moisture W to be supplied to the vapor S in the conditioning
valve
1.
To be more specific, as shown in Fig. 1, said discharge pipe 3 is provided
with a moisture drain 4 having a drain hole 4a at or near the bottom portion
of
the horizontal section 3a, said moisture drain 4 is provided with a moisture
transport conduit 5 for conveying moisture W, extracted from the moisture
drain
4 to the vapor cooler 1.
This moisture transport conduit 5 is a tubular element having a
predetermined diameter, and connected to a reduced annular area 9 constituting
a predetermined area of the conditioning valve 1, where a steam S1 flowing in
the conduit will flow faster than the steam flowing in the larger diameter
discharge pipe 3.
Referring to Figure 2, an annular reduced diameter section 9 is disposed
in the lower portion of conditioning valve I at a position near the jet nozzle
7 of
the conditioning valve 1. A nozzle 5a of the moisture conduit 5 exits into
this
reduced diameter section 9, and it is so configured that the moisture W, in
the
4


CA 02405397 2002-09-27

moisture conduit 5 is injected into depressurized steam S, path, in this
reduced
diameter section 9.
This reduced diameter section 9 obtains improved cooling effect by
maintaining the steam S, flow rate immediately passing through the reduced
diameter section 9 faster than the vapor S, passing through the discharge pipe
3, thereby reducing the pressure at the position of the reduced diameter
section
9 below the pressure in the discharge pipe 3. This pressure drop in a reduced
diameter section 9 is due to the increased velocity of a constant flow volume.
Such an effect is well known in the art and is referred to as a Venturi
effect.
Consequently, this embodiment of the present invention allows return of the
moisture W, from the discharge pipe 3 to the conditioning valve 1 by
connecting
the nozzle 5a of moisture transport conduit 5 to this reduced diameter section
9,
and drawing the moisture W, from the nozzle 5a into the conditioning valve 1
using the differential pressure generated by the Venturi negative pressure
phenomenon.
Considering the optimal conditions for the circulation method using this
differential pressure, it is preferable to set this level difference to 10
meters or
less, in the case where the moisture drain 4 is placed lower than the nozzle
5a
(no limitation in the case where the moisture drain section 4 is placed higher
than the nozzle 5a).
In this embodiment, the vapor S, differential pressure is used as
mentioned before, as a means for recycling the moisture W, flowing from the
conditioning valve 1 back to the conditioning valve 1. The system also permits
connecting the moisture transport conduit 5 to a desired position of the
conditioning valve 1 by disposing a forced delivery apparatus (for instance a
pump or the like), in the middle section of the moisture transport conduit 5.
Composed as described above, this embodiment desuperheats the steam
S in the conditioning valve 1, and the desuperheated and depressurized steam
S, is discharged from the conditioning valve 1 together with moisture W into
the
discharge pipe 3. The steam S, flowing through discharge pipe 3 is introduced
into the steam work section 2 connected to the distal end of the discharge
pipe
3. The moisture W, flowing at the bottom of the discharge pipe 3 is extracted
by
5


CA 02405397 2002-09-27

the moisture drain 4, transferred by the moisture transport conduit 5 and
recycled as moisture W for cooling in the steam conditioning valve 1.
Therefore, this embodiment provides for an energy efficient removal of the
moisture W, from the horizontal section 3a of the discharge pipe 3, thereby
preventing the moisture W, from stagnating at the bottom of the discharge pipe
3, avoiding as much as possible the pipe 3 deformation (damage) and the
detrimental effect to the temperature detection sensor and other problems of
the
prior art. Additionally, the present invention provides for recycling the
moisture
W, used for cooling the vapor S, in the conditioning valve 1 providing for
energy
efficient cooling.

6

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2009-08-04
(22) Filed 2002-09-27
(41) Open to Public Inspection 2003-07-04
Examination Requested 2006-06-07
(45) Issued 2009-08-04
Deemed Expired 2016-09-27

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Registration of a document - section 124 $100.00 2002-09-27
Application Fee $300.00 2002-09-27
Maintenance Fee - Application - New Act 2 2004-09-27 $100.00 2004-09-03
Maintenance Fee - Application - New Act 3 2005-09-27 $100.00 2005-09-01
Request for Examination $800.00 2006-06-07
Maintenance Fee - Application - New Act 4 2006-09-27 $100.00 2006-09-05
Maintenance Fee - Application - New Act 5 2007-09-27 $200.00 2007-09-12
Maintenance Fee - Application - New Act 6 2008-09-29 $200.00 2008-09-03
Final Fee $300.00 2009-05-19
Maintenance Fee - Patent - New Act 7 2009-09-28 $200.00 2009-09-18
Maintenance Fee - Patent - New Act 8 2010-09-27 $200.00 2010-08-30
Maintenance Fee - Patent - New Act 9 2011-09-27 $200.00 2011-08-30
Maintenance Fee - Patent - New Act 10 2012-09-27 $250.00 2012-08-30
Maintenance Fee - Patent - New Act 11 2013-09-27 $250.00 2013-08-30
Maintenance Fee - Patent - New Act 12 2014-09-29 $250.00 2014-09-22
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
DRESSER, INC.
Past Owners on Record
HIGUCHI, HIROYUKI
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Claims 2002-09-27 4 150
Drawings 2002-09-27 3 49
Representative Drawing 2002-12-12 1 7
Cover Page 2003-06-20 1 39
Description 2002-09-27 6 276
Abstract 2002-09-27 1 22
Claims 2006-06-07 5 161
Description 2006-06-07 7 291
Description 2008-08-27 7 306
Claims 2008-08-27 4 130
Representative Drawing 2009-07-08 1 8
Cover Page 2009-07-08 2 43
Assignment 2002-09-27 7 283
Correspondence 2009-05-19 1 40
Prosecution-Amendment 2006-06-07 9 290
Prosecution-Amendment 2008-05-05 3 91
Prosecution-Amendment 2008-08-27 9 320