US1476801A

US1476801A - Turbine

Info

Publication number: US1476801A
Application number: US118577A
Authority: US
Inventors: Hans P Dahlstrand
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1916-09-05
Filing date: 1916-09-05
Publication date: 1923-12-11
Anticipated expiration: 1940-12-11

Description

Dec. 11 1923. Y 1,476,801 H. P. DAHLSTRAND TURBINE Original Filed Sept. 5. 1916 Patented Dec. i1 1923.

ens erases-earner HANS P. DAHLSTEAND, F \WAUWATUSA, WISCONSIN, ASSIGNGR TO ALL1S--CHALI%EFRS MANUFAGTURIZG-GOMPANY, OF MELVIAUKEIL, 'WISCGNSIKT, OQTEZPORATION OF f nnnriwsnn.

Application-filed September- 5, 1916,3eria1 IEO. 118,57Y. Renewed septeznbcr. i922. Serial No. 580,5 l8.

An object of the invention is to providean elastic fluid turbine whichis simple and durable in construction and efficient in operation.

' din utilizing'the energy of elastic fluid, sucl' as steam, to its fullestextent, it has in some cases been found advantageous to use fluidhaving relatively high initial pressure and to expand this fluid to as near ZGXO (absolute pressure) as possible, In prime movers, such as turbines, operated by fluid under such relatively high initial pressures, as well as in those utilizingrlatively large volumes of fluid, it has been found that by employing entire or undivided stages of low pressure, the ,blad'ing. in the low pressure stage must be made excessively large in or der to permit eiiicient and complete expansion of the working fluid. The use ofsuch large lading is objectionable due to the relatively resulting diameter oi the low pressure stage. and also due to the enormous stresses set up in the blades while the machine is in operation. L

In order to maintain the size of the blading and of the rotor diameter within desirable limits, it has heretofore'been proposed to divide a low pressure stage into two parts .vhich receive their supply of fluid directly from the exhaust of one or more entire initial stages. in one of the proposed turbines of the prior art embodying a divided low pressure. stage, the divisions were formed as radial flow sections, while in another the divisions wereformed as axial flow sections the fluid flowed in opposite axial Ten-Brian.

in an axial direction opposite to the direction 01" flow in the low pressure'turloines.

On account oi the diiiieulty in designing and constructing radial flow turbines, it is more desirable to have ithe divisions of the low pressure stage formedas axial flow sec tions. It is also desirable .to have the di-. visions 'tormed as nearly alike as possi is in order to reduce the cost of construction to. a minimum. Another desirable feature is to have all of the stages deliver power to the same shaft and housed within a single casing which is devoid oi excessively long steam passages. I I 7 Q In order to accomplish these desirable results the present. invention contemplates the provision of-a single, unidirectional, axial flow turbine comprising'one or more high pressure stages and a divided low pressure stage having two or more divisions of similar construction. The divisions of the low pressure stage deliver power to a shaft which is connnon to all of the stages, and are housed withina single casing. The low pressure stage divisions receive their fluid SdPDly directly fromtheexhaust of a stage of higher pressure and delivertheir exhaust to a common condenser. The blading of the several divisions of the low pressure stage is, of the same kind, the divisions also being preferably formed of substantially thesame diameter.

A clear conception of an embodiment of the invention be had by referring to the drawing accompanying and forming a part ofthis specification in which like reference characters designate the same or similar parts in the various views.

Fig; 1 is a diagrammatic vertical sectional view through a compound or multiple expansion. elastic fluid turbine.

Fig. 2 is a diagrammatic transverse V01" tical section through the. turbine disclosed in Fig. 1, the section-being taken along the line 11 11 of Fig. 1. looking in thedi- .rection of the arrow. V

-'The compound turbine disclosed coinprises essentiallya plurality of stages 2, 3, 4, 5.. niountcd upon conunon main shaft (3 which is supported in end hearings in the usual manner. and which is preferably directly connected to an electric geii' nl nr or other energy absorber. The stages of the turbine are preferably arranged in successive order, the high pressure stage 2 being iollowed by the intermediate stage 3, which in turn is followed by the first division 4: of the low pressure stage, which is followed by the second eivision 5 of the low pressure stage. The rotor is preferably housed within a single casing 7 which is divided along a horizontal plane in order to permit access to the rotor bladiugr A suitable end thrust balancing device 9, uct- "uated by elastic fluid, is-provided'at anend Y of the. turbine rotor and is o1. usual construction'.. 1 s r The hi h pressure stage 2 is provided with an an'nuler high pressure chamber 13 7 4 of the low pressure stage is provided at its inletiend with an annular low pressure chamber'lti which receives steam directly from the exhaust 'end ott the intermediate stage 3. The second division 5 of the low pressure stage is provided at its inlet end ,with an annular auxiliary low pressure chamber 17 Y which communicates directly with the low pressure, chamber 15 by a series of conduits or passages 16. T divisions 4, 5, of the low pressure stage have their exhaust ends communicating directly-with a common exhaust chamber 18 which communicates with a condenser in the usual manner. 1

' The admission of steam to the high pressure end of the turbine through the valves 11, '12, is controlled by means of a speed governor 8' operating upon these valves through a relay -mechun1sm. The relay mechanism. disclosed comprises essentially a regulating valve 19 of usual form and a servo-motor 20 adapted to actuate the valves 11 12. i

' During the/normal operation of the turbine, elastic fluid, preferably steam under pressure, is admitted to the high pressure chamber 13 through the high pressure inlet valve'll.and pesses from the chamber 13 through the high pressure stage 2 to the intermediate pressure chamber 14.

FY0111 the intermediate pressure chamber 14L. the steam passes through the intermediate stage 3,'being' delivered in a partially expanded condition to the low pressure'chamber 15. From the low rressure chamber 15 a portion of the partially expended steam passes directly through the first division 4t of the low pressure stage, while the remainder of the steam passes through the conduits or pussu-ges 16 into the auxiliary chamber 17, from which this remainder passes through the second division 5 of the low pressure stage. The steam after passing through the divisions 5, is delivered directly into the chamber 18 from which itis withdrawn into the condenser. It the supply of steam admitted from the chzunber 13 to the high pressure stage 2 is ii'isuliiicient to properly carry the loud, the by-puss valve 12 is opened and high pressure steam is admitted directly to the intermediate pressure chamber 11 from which it passes through the intermediate and low pressure stages.

It will be noted that by constructing the compound turbine with divided low pres 5 re sta ge, maximum expansion of the steam with minimum length of low pressure blading and minimum diameter of low pressure sections, it attainable. The divisions 41, 5, of the low pressure stage may rcudily be made of: like construction throughout, thereby reducing the cost of construction to a minimum. By providing a single casing for all of the turbine stages, the cost of constructions is still further reduced. The provision of relatively short passages between the stagos, also rcduccs the cost of construction by reducing the length of the unit to a minimum and increases the cfiicicncy by avoiding excessive heat radiation. .Vhile the turbine disclosed has it low pressure stage divided into only two divisions, it will be noted that the division of this stage may be extended if desired. It is also immaterial so far as the present invention is concerned, whether one or more high pr ssi. e stages are, employed.

It should be understood that it is not desired to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent,-

1. In turbine, a high pressure stage having" an inlet, a plurality of low pressure stages each communicarting directly with a. common admission chamber, and means for admitting high pressure motive fluid to said turbine between said high pressure stage inlet and said low pressure stage admission chamber.

2. In a turbine, a high pressure stage having high pressure admission chamber, a plurality of low pressure stages cach comm inic:1 ,in;r directly with 21v common low pressure admission chamber associated with said high pressure stage, and means for ad mitting high pressure motive fluid to said turbine between said admission chambers.

Hi l

sure stages each communicating directly with a common admission chamber, a valve for admitting motive fluid to saidturbine between said high pressure stage inlet and said common low pressure stage admission chambenand a governor controlling the operation of both of said valves.

4. In a turbine, a high pressure stage having a high pressure admission chamber provided with high pressure fluid inlet means, a plurality of low pressure stages each communicating directly with a common low pressure admission chamber associated with said high pressure stage, 'means for admitting high 'essure motive fluid to said turbine between said admission chambers, and a governor cont-rolling the operation of both or" said high pressure inlet and admission means.

5. In a turbine, a high pressure stage hav- 'ing an inlet, a plurality of low pressure stages located at one end of said high'pressure stage and communlcating directly with a common admission chamber, and means "for admitting high pressure motive fluid to said turbine between said high pressure stage inlet and said low'pressure admission chamber.

6. In a turbine, a'high pressure stage having an inlet, a plurality of low pressure stages communicating directly With a common admission chamber and with a common exhaust chamber, and means for admitting high pressure motive fluid to said turbine between said high pressure stage inlet and said low pressure stage admission chamber.

7. In a turbine, a high pressure stage hav ing an inlet, a plurality of low pressure stages located at one end of said high pressure stage and communicatmg directly with a common admission chamber and with a common exhaust chamber, and means for admitting. high pressure motive fluid to said turbine, between said high pressure stage inlet and said low pressure stage admission chamber. q

8 In aturbine, a high pressure stage hav ing an inlet, a plurality of low pressure stages through which fluid flowsin the same axial direction, said low pressure stages communicating directly with a common ad-' mission chamber, and means for admit-ting high pressure motive fluid to said turbine between said high pressure-stage inlet and comprising one type of blades and having an inlet, a plurality of low pressure stages comprising the same type of blading, said low pressure stages communicating directly with a common admission chamber, and means for admitting high pressure motive fluid to said turbine between said high pressure stage inlet and said low pressure admission chamber.

In testimony whereof, the signature of the inventor is aiiixed hereto. 7

HANS P. DAHLSTRAND.