US986749A - Turbine. - Google Patents

Description

0. A. PARSONS & s. s. 000K.

TURBINE.

APPLIOATION FILED JULY 9, 1910.

986,749. Patented Mar.14,1911.

3 SHEETS-SHEET 1.

G. A. PARSONS 6: S. SI COOK. TURBINE.

APPLIOATION FILED JULY 9, 1910.

Patented Mar. 14, 1911.

3 SHEETS-SHEET 2.

'0. A. PARSONS 1 513100011.

. TURBINE. APPLICATION FILED JULY 9, 1910.

3 SHEETS-SHEET 3.

TL IITUIT JWIWI JH Patented Mar. 14}, 1911.

UNITED STATES-PATENT OFFICE.

CHARLES ALGERNON PARSONS; or" nEwoAsrLE-UroIt-TYNn, AND STANLEY SMITH 000K, or WALLSEND-UPON-TYNE, ENGLAND; SAID COOK ASSIGNOR 'ro sAID PARSONS.

' TURBINE.

Specification of Letters Patent.

Patented Mar. 14, 1911.

Application filedluly 9, 1910. Serial No. 571,214.

vTo all whom it may concern:

' invented certain new and useful Improyements in and Relating to Turbines, of whlch the following is a specification.

This invention relates to compound turbines of the type in which the steam is allowed to flow through a segmental portion only of the annulus between the wheel carrying the rotating blades and the casing carrying the fixed blades and 'rn-w hich the "telocity of the steam through the successive rows of guideblades and rotating blades is maintained chiefly or entirely by dropping pressuresmall amounts at a time, as occurs for instance in the well known Parsons type of blading, these-small drops of pressure occurring in either or in both the fixed guide blades and rotating blades. Such turbines may conveniently be said to be of the partial impingement with fractional conversion of pressure ty e.

Various turbines of this 0 aracter are de-' scribed in our Patents Nos. 28047/1907,

17 872/1908 (in the complete specification of which is cognated the provisional specification N0. 28374/1908); 28373/1908,

28375/1908 and 28376/1908.- 1

In turbines of the above character it is usual to provide short end blockings or stops at each end of the sectors of guide blades in order to revent leakage of steam in a circumferential direction. These blockings are adapted to extend as close to the rings of rotating blades as is possible; they are also continued for a short distance only on each side'of the sectors of guide blades so as to avoid loss due to skin friction between the rotating rings of blades and the blockings. From its point of. exitfrom the short end blockings on one side of a sector of. guide blades or impingement zone, toxits entrance between the short end blockings on the other side of the same impingement zone or between the blockings on one side" of another impingement zone, the rotating blades run in a chamber filled with steam 1 enter.

at a pressure above or below that existing in the impingement zone from which they are issuing or into which the are about to In turbines of this 0 aracter there has therefore been hitherto an-unavoidable loss owing to a volume of steam being held between the rotating blades and carried from a place of one pressure to aplace where a lower pressure exists, a certaln quantity of steam being thus transferred from aplace of higher density to a place of lower density without doing any work.

The object of the present invention is to prevent the loss hitherto occasioned by the transference of the volume of steam held in the rotating blades.

The invention consists broadly in withdrawing steam from the rotating blades during their passage through one set of short end blockings and delivering it to the blades when passingthrough another set of short end blockings whereby increased eoonom is obtained.

I The Invention also consists for this purpose in connecting the spaces between adj acent short end blockings on one side of an impingement zone by means ofmne or more passages with the spaces between adjacent short end blockings on the other side of the same impingement zone. By this means when the pressure of the steam in the impingement zone is higher than the pressure existing in the chamber, part of the volume of dense steam, held between the rotating blades, and which would otherwise enter the chamber, is transferred through this passage and caused to fill up the blades which are running into the impingement zone from the chamber where the lower pressure exists. In the case when theim-.

.pingement zone is at a lower pressure than the chamber, part of the volume of denser steam, held in the rotating blades about to enter the impingement zone, is transferred through this passage andcaused ,to enter the blades again as they leave the 1mpinge ment zone and; are about .to reenter the chamber. Thus a certain amountof steam which would otherwise be carried over from the impingement .zone into the lower pres sure chamber or from the chamber into a lower pressure impingement zone and 'consequently lost, is bein continuously restored t'o'the part "of big er-pressure.

It is obvious that a passage may be pro 'vided for every pair of corresponding short endblockings or they may only be provided where the difierence ofpressure between the impingement zone and'jthe chamber 1s greatest. In some cases itmay be preferable to' "leaving this zone, or conversely, -is thus effected at various points successively intermediate between the pressure .in the impingement zone and the pressure in the chamber in which thewheel is situated and the leakage of steam-into or from which it is desired to diminish. g i It is preferable that the end of a passage receiving the steam from the rotating blades should be expanded in order to facilitate the outflow ofsteam from the blades into the passage, and also that the end delivering steam-to the blades should be restricted so as to give a slightly increased velocity to the steam-"to facilitate its inflow into the blades, and gto avoid any retarding effect as the steam strikes these blades. .If the openings of these connecting passages are formed ob lique toagree with the direction of rotation of the rotating blades, the entry and exit of the steam to and from the blades and passages also facilitated.

The invention also consists in the arran ernen'ts of connecting passages as herein'a erindicated. I

' Referring now to the accompanying drawings which are diagrammatic only ;Figure 1 1s apart longitudinal section on the line B-B of Fig. 2, of a turbine according to the present invention. Fig. 2 is a parttrans- -verse section on the line AA of Fig. '1.

Fig. 3 is an .inverteddeveloped view on the line D-EF of Fig. 2. Figs. 4 and 5 are part views similar to Figs. 1 and 2; showing a modification of'the invention. Figs. 6-16- show further modifications.

In carryin this invention into effect for instance as s own in Figs.- 1, 2 and 3, in a turbine in which the steam'fiowsin one direction through one series ofguide blades a .and rotating blades b and is then discharged into-a chamber a from which it passes by means of a second series of giiide blades a in -the same direction to its exit from the chamber, we arrange one or more passages e connectin the short end blockings f on each side of t e same sector of guide blades. The passa es e as shown in Figs. 1 and 2, are fo rme completel ber g which is secure by bolts It, as shown or otherwise fastened to the turbine casing i.

and which carries the guide blades 0 and short end block'ings f the passagese inthis- 'member 9 being-arranged to open into the space between the adjacent short end block-- passages are in a separate membetween the short end blockings f at the ends of adjacent sectors of guide blades are connected by a single passage e. Obviously however two or more such passages may be used if the pressure difference between the impingement zone and the chamber be very great.

Figs. 4 and'5 show a modification in which two passages e are provided, one set of such passages are formed in a member 9 as in the previous modification, while the second set are formed as grooves in this member which grooves are closed bythe casing z when the member 9 is in position. In some cases such as where thepressure in the impingement zone'isvery near to the pressure in the chamber 0 we may omit the passages e and only connect the short end blockings f where the pressure difference is higher. In other cases instead of providing two passages over the whole length ofthe impingement zone as shown in Figs. 4 and 5 we may arrange two passages at the cominencement of the impingement zone, where the pressure difference is greater and only one passage where the difference between the pressure in the zone and the pressure in the chamber is less.

I Various other methods of formin the connecting passages e are. shown in Figs. 6 to 16. For instance,as shown in Figs. 6 and 7, the passages e, are formed in the body of the casing i itself while in Fi 8 and 9, the passages are shown formed If grooves in the internal face of the turbine" casing these grooves .bemg closed by the member 9 on which the guide blades are mounted.

In a further construction shown in Figs. 10 and 11, holes m through the turbine casing 5 are provided and the passages e are formed by grooves in a member is securely fastened to the exterior of the casin z the grooves being adapted to register with the in Figs. 14 and 15 two sets of passages. e are shown formed in such a member 11..

The arran ement shown in Figs. 8 and 9 'may be mo ified by forming the grooves in the member 9 these grooves being closed by the turbine casing 71 as shown in connectiqn with one of the sets of passages in Figs. 4 and 5. In the case in which two or more rovided over the whole or only part of t e length of the impingement zone, we may. form some of these passages in the body of the turbine casing itself and some in a member attached to the exterior .of the casing in the. manner already explained or we. may arran that both these passages shall be formed mthe body of the casing itself. such cases in fact we may a whole length of the impingement zone are into the blades and to prevent any retardreferred to. For instance as shown in Fig. 1

-pingement zone are formed by grooves in entering the blades. Also the end of the arrange the passages partly in 'one and partly in another of the methods already 16, one set of passages e which extend the formed in the blade carrying member g while the second set of passages e which extend over only the-first part of the imthe turbine casing 2' which are closed by the member g.

As shown in all the modifications, we preferably form the ends of the passages 6 oblique to. agree withthe direction of rotation of the moving blades, b and restrict; the end of the passage delivering the steam to the blades in order to give a slight increase of velocity to the steam to facilitate its inflow ing effect that the steam might have when passage receiving the steam from the blades is expanded so as. to facilitate the' outflow of steam .flOlIl these blades. Any other convenient method of forming the passages between the short end blockings may be used, and we do not in anyway limit our invention to the particular arrangements herein described and shown.

In a'turbine of the kind shown in Figs. 1-3 in which the steam flows twice in the same direction through the rings of rotating blades 1) it will be seen thatthe rotating blades which are moving in the direction of the arrow 1, will as they leave the first impingement zone 0 give up part of the dense steam with which they are filled before they enter into the chamber 0 which is filled with steam oflower density. This steam will be transferred through the passage e and delivered into the rotating blades b as they pass from the chamber a into the samedmpingement zone 0. In the second impingement zone p where-the steam passes from the chamber 0 through the blades before passing into another part of the turbine it will be seen that the rotating blades 1) that" are about to enter the impingement zone p are filled with steam at a higher pressure than that which actually exists in such impingementzone. By means of the passages e however, part of this steam is by-passed. across the impingement zone 79 and is de-. livered into the rotatingblades b as they are about to pass from the lower pressure of the impingement zone 79 into the hi her pressure chamber 0. Thus in both tiese cases a certain amount of steam which would otherwise be carried from the higher ously restored to the part of higher presthe blades leaving the zone or conversely, it

will be seen, is eiit'ected at various points successively intermediate between the pressure in the impingement, zone and the pres sure in the chamber in which the wheel is situated and the leakage of steam into or from which it is desired to diminish.

This invention may be applied to any of the turbines" made in accordance with ourblades, no matter whether such ro'tat-ing' blades are of the Parsons or crescent formation. It is thus applicable to' all partial impingement turbines of the reaction type and also to those of the type in which the conversion of pressure into velocity takes place in fixed guide blades only, the velocity energy being transformed into mechanical energy on the rotating blades.

It will be seen that the method of carrying. this invention into effect is capable of various modifications without in any way afi'ecting thespirit of the same.

@HaVing now described our invention what we claim as new and desire to secureby Letters Patent is 1.. In combination with aturbine having partial impingement with fractional conversion of the pressure energy of the working fluid into kinetic energy, means for passing working fluid from one impingement zone boundary to another such boundary.

2. In combination with a turbine having partial impingement with fractional conversion of the pressure energy of the working fluid intokinetic energy, means for passing workingfiuidfrom the boundary on one side of an impingement zone to the boundary on the 'other side of the same zone. .3. In combination with a turbine having partialimpingement of the working blades with,-fractional conversion of the pressure energy of the working fluid into-kineticen ergy, means for receiving working'fluid from the blades at one impingement zone bound ary and for delivering the fluid so received into the blades at another such boundary.

4. In combination with a turbine having partial impingement of the Working blades with jfractional conversion of the-pressure energy of the working fluid intokinetic en;

ergy, means-for receiving steam from said working blades on one side of an impingement zone and for delivering the same into theworking blades on the other side of said zone. v i

5. In combination with a turbine having partial impingement with fractional conversion of the pressure energy of the working fluid into kinetic energy, short end blockings on each side of an im ingement zone and means for passing wor ing fluid from one set of such blockings to another set.

I ergy, short end blockings on each side of an v with fractional conversion of the pressure impingement zone, means for receivingworking fluid from said blades when passing between one set of said blockings and for de livering the same into saidblades on their passage through another set of short end bloekmgs.

7. In combination with a turbine having partial impingement of the working blades with fractional conversion of the pressure energy of the working fluid into kinetic energy, passages for passing working fluid from one impingementzone boundary to. another such boundary.

8. Incombination with a turbine having partial impin'ement of the working blades with fractional conversion of the pressure energy of the working fluid intokinetic energy, passages for passing working fluid from one impingement zone boundary to another such boundary,'the ends of said passages being inclined in the direction of rotation of the'working blades.

9. In combination with a turbine having partial impingement of the working blades energy of the working fluid into kinetic energy, passages adapted to. receive working fluid from the working blades at one impingement zone boundary and to deliver the .fluid so received into the blades at another such boundary.

10. In combinationwith a turbine having.

- fluid so received into the blades at another such boundary, the ends of said passages bey from one lmpingement zone ing inclined- 1n the direction ofrotation of the working blades.

11. In combination with a turbine having partial impingement of the working blades with fractional conversion of the pressureenergy of the working fluid intokinet1c 55 working fluid oundary to another such boundary, said asages at their receiving ends being expan ed and at their.

energy, passages for passing delivery ends being restricted in cross sectional area, said ends being inclined in the direction 'of 'rotation offthe working blades.

12." In combination with .a turbine having partial impingement of the working blades with Y fractional conversion. of 1 the pressure' energy of the workingfluidintb kinetic energy, assages adapted to receive working fluid rom the working blades at onepim- Eingement zone boundary and to deliver the uid so received into the blades at another such boundary, said passages at their receiving ends being expanded and at their'deliw ery ends being restricted in cross sectional area, said ends being inclined in the direction of rotation of the working blades.

13. In combination. with a turbine having partial impingement of the working blades with fractlonal conversion .of the pressure energy of .the' workingfluid into kinetic energy, passages adaptedto receive working fluid from said working blades on one side of an impingement zone and to deliver the same into the working blades on the other side of said zone, said passages at their receiving ends being expanded'and at their delivery ends being restricted in cross sectional area, said ends being inclined in the direction of rotation of the working blades.

14. In combination with a turbine having partial impingement with fractional conversion of the pressure energy of the working fluid into kinetic energy, short end blockings on each side of an impingement zone, passages adapted to receive working fluid from said blades when passing between one set of said blockings, and to deliver the same into said blades on their passage through another set of such blockings,

'Sflld passages at their receiving ends being expanded and at their delivery ends being restricted'in cross sectional are'a,'said ends being inclined in the direction of rotation of the working blades.

15. A turbine comprising in combination stationary elements co-acting with rotatin vanes fractionally to convert the therma energy of the workin fluid. into useful work, said stationary e ements only partly extending over said rotating vanes to form impingement zone or zones, and means for receiving working fluid from said rotating vane's at one impingement zone boundary and for deliverin the fluid so received into said vanes at anot er such boundary.

161A turbine comprising in combination stationary elements co-acting. with rotatin" vanes fractionallyto convert the therma energy of the workin fluid 'into useful work, said stationary e ements only partly extending oversaid rotating vanes and terminating in short end blockings to form impingement zone or zones, and means for receiving workin vanes when-passlng between adjacent block.- ings at one impingement zone boundary and for delivering the fluid so received into said vanes .on their passage between adjacent blockings at another such boundary.

17.- A turbine comprising in combination stationary elements co-acting with rotatin vanes, fractionally to convert the therma fluid from said rotating energy of the workin fluid into useful work, said stationary e ements only partlyextending over said rotatin vanes and ter minating in short end blockings to form im pingement zone or zones, passages connectstationary elements co-acting with rotating vanes, frabtionally to convert the thermal energy of the workin fluid into useful work, said stationary elements only partly extending over said rotating vanes and terminat-ing in short end blockings, to form impingement zone or zones, assages connecting the spaces between t e short end blockings .on one side of an impingement zone with the spaces between adjacent similar blockings on the other side of this zone, said passages at their receiving ends being expandedand at their delivery ends being restricted in cross sectional area, said ends being inclined in thedirection of rotation of the working blades.

' 19. A turbine comprising in combination stationary elements co-acting with rotating vanes fractionally to convert the thermal energy of the working fluid into useful work, said stationary elements only partly extending over said rotating vanes and terminating in short end blockings to form impingement zone orzones, a casing for said turbine, a member carried by said casing and on which said stationary elements are mounted, passages in said member connectin' the spaces between adjacent short end b ockings at one im ingement zone boundary, with the spaces blockings at another such boundary.

20. A turbine comprising in combination stationary elements co-acting with rotating 'vanes fractionally to convert the thermal energy of the working fluid into useful work, said stationary elements only partly extending over said rotating vanes and terminating in short end blockings to form impingement zone or zones, a casing for said turbine, a member carried by said casing and on which said stationary elements are mounted, passages in said member connecting the spaces between adjacent short end blockings at one impingement zone boundary, with the spacesbetween similar. blockings at another such boundary, said passages at their receiving ends beingex-panded and at their delivery ends being, restricted in cross sectional area, said ends being inclined in the direction of rotation of the working blades.

21. A turbine compri' 'ng in "combination stationary elements co-acting with rotating vanes fractionallfi to convert the thermal energy of the wor etween similar ing over said rotating vanes and terminating in short end blockings to form impingement zone or zones, a casing for said turbine, passages in said casing connecting the spaces between adjacent blockings at one impingement zone boundary with-the spaces between similar blockings at another such boundary. 22. A turbine comprisingin combination stationary elements co-acting with rotating. vanes fraetionally toiconvert the thermal energy of the working fluid into useful work, 1 said stationary elements onlyv partly extending over said rotating vanes and terminating in short end blockings to form impingement zone or zones, a casing for said turbine, passages in said casing connecting the spaces between adjacent blockings at one impingement zone boundary with the spaces between similar blockings at another such boundary, said passages at their receiving ends being expanded and at their delivery ends being restricted in cross sectional area, said ends being also inclined in the direction of rotation of the working blades.

23. A turbine comprising in combination stationary elements co-acting with rotating vanes, fractionally to convert the thermal energy of the working fluid into useful work, said stationary elements only partly extending over said rotating vanes and terminating .in short end blockings to form impingement zone or zones, a casing for said turbine, a member attached to said casing on the inner surfaceof the latter and on which said stationary elements are mounted, assages connecting the spaces between a jacent short end blockings at one impingement zone boundary with the space between simila'r ,blockings at another such boundary, said casing and closed by said member.

2 L A turbine comprising in combination stationary elements co-acting with rotating vanes,'- fractionallyto convert the thermal energy of the working fluid into useful Work, said stationary elements only partly extend ing over said rotating vanes and terminating in short end blockings to form impingement zone'or zones, a casing for said turbine, a member attached to said casing on the inner passages being formed as grooves 1n said surface of the latter and on which said stationaryelements are mounted, passages connecting the spacesbetween adjacent short end blockin s at one impingement zone boundary with the space between similar blcckings at' another such boundary, said passages being formed within said member; and at their receiving ends being expanded and at their delivery ends being restricted in cross sectional area, said ends being inclined in the direction of rotation of the working blades.

ng fluid into useful work,

25.:A turbine comprising combination within a chamber, stationary elements ooacting with rotating vanesjtactionall to ofthe' wor 'ngl convert the the mat .ener' fluid to useful work, said stationary elements only partly extendingover said rotating vanes and terminating in 'short' end blockings to form impingement zone 01,

.zone or zones and the fluid in said chamber, passages connecting the spaces between the short end blockin s at one impingement zone boundary with t e spaces between similar esefmo blockings at another such boundary, the

number of such'passages openin into 'each of said spaces varym lnaccor ance with I the degree of pressure ifierence existing between this (part of said impingement zone or zones an said chamber.

In testlmony whereof, weafiix our s1gna tures 1n presence of two wltnesses.

0mm cannon PARSONS. ST ANLEY smru 000K.

Witnesses:

FREDERICK Gonnon HAY Bnnronn, WILLIAM DAGGE'I'I.

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