Title of Invention

"AN AXIAL EXHAUST HOOD INTERPOSED BETWEEN THE LOW-PRESSURE CYLINDER OF A TURBINE AND A CONDENSER

Abstract The invention relates to an axial exhaust hood interposed between the low-pressure cylinder of a turbine and a condenser to recover the leaving energy in the working medium of a turbine comprising: an upper part (p) having plurality of circumferentially continuous outlets (1) for establishing an inter-communicating relationship with said condenser downstream; a lower-part (q) having correspondingly profiled equal number of outlets (1) for engagement with downstieam of said condenser, characterized in that said upper part (5) and said lower part (q) are secured together in the horizontal plane in a non-rotatable manner by in-built flange members (4) and said exhaust hood assembly being disposed axially in relation to said turbine and said condenser. {Figs-1,2&3}
Full Text FIELD OF THE INVENTION
This invention relates to an exhaust hood for turbines.
This invention further relates to an axial exhaust hood for turbines, which is used to
recover the leaving energy in the working medium of a turbine before entering into
surface condenser for condensation in a thermal power plant and while interconnecting
the low pressure cylinder of a turbine with a condenser.
BACKGROUND OF THE INVENTION
The working medium leaving the last stage of a turbine contains energy in the form of
velocity which if not recovered is lost and a diffuser is generally provided for recovering
this leaving energy. This diffuser is generally held in a exhaust hood which also serves
the purpose of directing the said medium into the condenser.
The most prevalent exhaust hood is a downward exhaust hood wherein the condenser is
placed directly below the exhaust hood and the flow turning into the condenser takes
place in the exhaust hood. Recovery of energy from the velocity of the medium leaving
the turbine is complex in mis set up. Further, much of the medium escapes and cannot be
condensed and as a result, the energy goes untrapped.
OBJECTS OF THE INVENTION
It is therefore an object of mis invention to propose an exhaust hood for connecting the
condenser axially in relation to the position / location of steam turbine which efficiently
recovers the energy of the medium leaving the turbine.
It is a further object of this invention to propose an axial exhaust hood which allows the
medium to be dumped into the surface condenser for condensation.
These and other objects and advantages of the invention will be apparent from the
ensuring description.
DESCRIPTION OF THE INVENTION
An axial exhaust hood inteiposed between the low-pressure cylinder of a turbine and a
condenser to recover the leaving energy in the working medium of a turbine comprising:
an upper part having plurality of circumferentially continuous outlets for establishing an
inter-communicating relationship with said condenser downstream;
a lower-part having correspondingly profiled equal number of outlets for engagement
with downstream of said condenser-, characterised in that said upper part and said lower
part arc eoeured together in the horizontal plane in a non-rotatabla manner by in-built
flange member (4) and said exhaust hood assembly being disposed axially in relation to said turbine and said condenser.
According to this invention is provided an axial exhaust hood for turbines comprising a plurality of outlets for connecting a surface condenser axially in relation to the turbine. In accordance with this invention, an axial exhaust hood for turbines is provided, where the hood connects the condenser axially in relation to the position /location of low-pressure module of the turbine, The axial exhaust wet medium through its outlets connected to plurality of pipes, for dumping to the condenser. The hood has
plurailty of outlets in the upper half and matching number of outlets with pipes in the lower half The pipes may be of any cross section, such as circular, rectangular or square, preferably circular. The exhaust hood includes plate ribs on the lower half and upper half The designation of the hood is with respect to the area at the exit of LP module of steam turbine. The size of the axial exhaust hood is represented with the last stage LP biade annulus area (for eg.3.2 sq.m axial exhaust hood for 3.2sq.m LP blading. The exhaust hood has an area of cross section of at least 0.2 sq.m. The mounting of the last stage guide blade carrier is within the exhaust hood and bursting diaphragms are mounted in the top half The hood is also provided with guide mounted in the lower half BRIEF DESCRIPTION OF THE ACCOMPAYING DRAWINGS The invention will now be described in greater details with reference to the figures of the accompanying drawings:
Fig. 1 shows tlie assembly of the axial exhaust hood: Fig. 2 shows the lower half of axial exhaust hood; Fig. 3 shows the upper half of the exhaust hood.
Fig. 1 shows the overall assembly of the axial exhaust hood duly indicating the lower part (q) of the exhaust hood (Fig.2) and upper part (p) of the exhaust hood (Fig.3). The four circular outlets (i) are shown at the exhaust of the exhaust of the hood. The outlets are terminated with a matching flange (2) with holes for bolting to the condenser downstream. The axial exhaust hood is also provided with plurality of bursting diaphragms (3) in the upper half of the assembly. The upper half and lower half are joined together at the parting plane through flanges (4) and locking means. The axial exhaust hood consists of a circumferentially continuous inlet section wherein die guide blade carrier (5) of an LP stage of turbine is fixed as can be clearly seen in die lower half of the exhaust hood shown in Fig.2. The medium after passing through the LP blades enters the latter part of the exhaust hood where in the branching of the medium takes place into plurality of outlets. These outlets carry the medium through the corresponding number of pipes (1) and get connected to the condenser by a locking means comprising of a connecting members and a housing member. The whole flow passage is divided into circular, rectangular and circular cross sections through suitable transition pieces. Suitable ribs (6) have been provided outside and also inside for providing the required mechanical rigidity, Lifting Lugs (7) are provided at switable
locations for lifting the lower part and upper parts separately for assembly and dismantling as needed. A guide arrangement (8) is provided in the lower half which is used for aligning the exhaust hood witli respect to the turbine and condenser along with foundation. The rotor of the turbine protrudes out of the axial exhaust hood towards the rear end and the rotor is positioned in a bearing housed in a pedestal, not shown in the figure. The gland seals are also mounted on the rotor protruding out of the exhaust hood.





WE CLAIM:
1. An axial exhaust hood interposed between the low-pressure cylinder of a turbine
and a condenser to recover the leaving energy in the working medium of a turbine
comprising:
an upper part (p) having plurality of circumferentially continuous outlets (1) for establishing an inter-communicating relationship with said condenser downstream; a lower-part (q) having correspondingly profiled equal number of outlets (1) for engagement with downstream of said condenser, characterized in that said upper part (5) and said lower part (q) are secured together in the horizontal plane in a non-rotatable manner by in-built flange members (4) and said exhaust hood assembly being disposed axially in relation to said turbine and said condenser.
2. An axial exhaust hood as claimed in claim 1 wherein said upper part has plate ribs (6) on the outer and the inner surface.
3. An axial exliaust hood as claimed in claim 1 wherein said upper part (p) has plurality of bursting diaphragms (3).
4. An axial exliaust hood as claimed in claim 1 wherein said outlets (1) are provided wife matching flange members (2).
5. An axial exhaust hood as claimed in claim 1 wherein said upper part and said lower part are secured to the condenser downstream by a locking means comprising of connecting member and a housing member.
6. An axial exhaust hood as claimed in claim 1 wherein said lower part is provided with guide arrangement (8) for aligning said hood along the foundation.
7. An axial exhaust hood as claimed in claim 2 wherein said lower part is provided with plate ribs (6) on the outer and inner surface of the lower part.
8. An axial exhaust hood as claimed in claim 1 wherein said upper part (p) has a corresponding inlet section for mounting the last stage guide blade carrier (5) of said turbine.
9. An axial exhaust hood as claimed in claim 1 wherein said outlets (1) carry steam through four pipes.
10. An axial exliaust hood as claimed in claim 1 wherein said flange member (4) is provided with holes to receive said locking means.
11. An axial exhaust hood as claimed in claim 1 wherein said upper part and said lower part are provided with lifting lugs (7) for lifting, shifting and holding of both said parts individually or in combination.
12. An axial exhaust hood as claimed in claim in any of the preceding claims wherein said upper part and said lower part is fabricated from steel plates and can be cast for smaller sizes.
13. An axial exhaust hood as claimed in claim 1 wherein said pipes are circular cross section pipes.
14. An axial exhaust hood as claimed in claim 1 wherein area of cross-section of said hood is designated with respect to the area of the exit of LP module of steam turbine.
15. An axial exhaust hood as claimed in claim 1 wherein cross-section of said hood ranges between 0.2 sq.m to 10 sq.m.
16. An axial exhaust hood as claimed in claim 1 wherein said upper part said lower part when differently shaped, the cross-sectional profile of said hood changes, for eg. to rectangular or square.
17. An axial exhaust hood substantially as herein described and illustrated with reference to the accompanying drawings.

Documents:

42-del-2003-abstract.pdf

42-del-2003-claims.pdf

42-del-2003-complete specification (granted).pdf

42-del-2003-correspondence-others.pdf

42-del-2003-correspondence-po.pdf

42-del-2003-description (complete).pdf

42-del-2003-drawings.pdf

42-del-2003-form-1.pdf

42-del-2003-form-19.pdf

42-del-2003-form-2.pdf

42-del-2003-form-3.pdf

42-del-2003-form-5.pdf

42-del-2003-gpa.pdf

abstract.jpg


Patent Number 239362
Indian Patent Application Number 42/DEL/2003
PG Journal Number 12/2010
Publication Date 19-Mar-2010
Grant Date 16-Mar-2010
Date of Filing 16-Jan-2003
Name of Patentee BHARAT HEAVY ELECTRICALS LIMITED
Applicant Address SIRI FORT, NEW DELHI-110 049, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 GOVINDARAJU VENKATA RAMANA MURTY CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA.
2 CHODAVARAPU NAGA VENKATA RAMANA CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
3 BIHARI LAL JAISWAL CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
4 ABHAY SHIVRAM PANWALKAR CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
5 MANJESWAR MOHAN PRABHU CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
6 GAJA BALAKRISHNA CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
7 SUBHAKOTI RAGHAVACHARY CORPORATE RESEARCH & DEVELOPMENT, VIKASNAGAR, HYDERABAD 500 093 A.P.INDIA
PCT International Classification Number F01D 1/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA