US1688413A - Method of and apparatus for increasing the vacuum of turbines - Google Patents

Description

Oct. 23, 1928. 1,688,413

A.DELAS FOR INCREASING THE VACUUM OF TURBINES METHOD OF AND APPARATUS Filed Oct. 19 1920 Patented Oct. 23, 1928.

UNITED stares 1,688,413 PATENT", OFFICE.)

ALBERT DELAS, or PARIS, FRANCE, Assienon T0 DELAS coivnnnsnn coaronnrron,

or NEW YORK, 1\T.. Y., AoonPonAmoN or DELAWARE.

METHOD OF AND APPARATUS FOR INCREASINGfT-HETVACU-UM' OI." NBBINES'.

Application filed October-19, 1920, Serial No. 417,990,311! in France Iovemberifl, 1919.

The invention forming the subject matter of the present application relates to steam tur-. bines andhas for its principal object to provide a method, and means for carrying such method into practice, of reducing the drop in pressure between the exit end of the turbine blades, or vanes, and the condenser.

The use of higher and higher expansions in the design and operation of steam turbines and consequently the use of very high vacuums at the exit of the last blades, in order considerably to diminish the specific consumption of the turbines, has led to a diflicult problem. It has been found that the drop of pressure between the exit of the blades and the condenser has a considerable detrimental influence upon the efficiency of the turbine.

Attempts have been made to reduce this drop in pressure by designing or making the dimensions of the steam passages or channels such as to reduce the average flow of the steam or other fluid therethrough. Although this expedient is efficacious for a quiet steam flow, progressing at even speed and in parallel paths, experience has shown that it is much less efiicient for steam which issues from the turbine blades in an agitated condition and in which there are whirls and eddies due, among other causes, to the changes of direction of flow to which it is subjected in the steam collector. I

Experiments madeon steam ejectors forming the subject matter of my French Patents 488,782, of Feb. 4, 1918, and 491,620, of Sept. 6, 1918,.and my copending U. S. applications, Ser. Nos. 260,6O0y 260,601 and 324,391, have shown that cooling of the walls of the diffuser causes the sup ression of eddies, by the fixation of the incident molecules or par ticles, with a consequent increase of efficiency. This increase of efliciency' is greater than would be expected in view of the small quantity of steam actually condensed.

The observations made in connection with the important improvements in ejectors led to the solution of the problem of reducing the drop in pressure above mentioned in connection with turbines. .I solve this problem in the steam collectors and if desirable or necessary in the exhaust-pipes thereof.

The method may be best explained and understood. by describing one of. the formsof apparatus which may be employed to carry the same into practice. Referring to the by cooling the walls I drawings which illustrate what I now consider a preferred form of the invention:

Fig. I is a somewhat diagrammatic secprises a stator 1, provided with blades or vanes 2, and a rotor 3 provided with blades or vanes 4. Steam, or other elastic motive fluid, may be supplied to the turbine in any of the well known ways and, after having passed through the stages of the machine, passes into the exhaust steam collector5. From the collector or chamber 5 the steam passes to a condenser 10 through the discharge opening 6 and any suitable connections. I condense the steam which impinges upon the walls of the collector 5 by cooling the walls of the latter. One means for accomplishing this result may be constructed substantially as follows:

The steam collector or chamber 5 is pro vicled with a double envelope or acket 7 in which is established a circulation of cold water (or other cooling fluid) on all of its surface or only on the parts directly impinged by the stream of steamleaving the blades of the turbine. The water orcooling fluid may be introduced at 8 and discharged at 9 or vice versa.

This circulation may be extended to the piping or conduit connectingthe turbine to the condenser, should the shape of said pipe or conduit be such as to produce or tend to produce eddies. I

The walls which are cooled should preferably be constructed of metal, of-good heat con ductivity such as aluminum, bronze, etc.

By virtue of the method and means above described the drop in pressure from the steam exit at the blades of the turbine to the condenser is effectively and greatly' reduced.

What Inow consider the theory of operation 100 of my invention will be clearly apparentfrom the foregoing description in view of the disclosure in my copending applications and patents above mentioned.

lVhat I claim is 1. In combination, a. condenser, a turbine adapted to be supplied with condensable elastic motive'fluid and to discharge the'same into cated between the turbine and condenser, and

said condenser, an exhaust fluid collector lomeans whereby a cooling liquid is passed in 9:

2 1,eee,41s

of said collector." means forming a cooling jacket around at 2. In combination, a condenser, a vaporleast a portion of said first named means, the actuated turbine provided with means for inner Wall. of said jacket being of metal of 5 conveying its exhaust to said condenser, and conip'a 'atively high heat conductivity.

least a portion of said first namedlneans. nature. 7 I a 3. In combinatlon, a condenser, a vapor actuated turbine provlded with means forcon- ALBERT DELAS.

contact With at least a portion of the Walls veying its exhaust to said condenser,- and means forming a cooling jacket around at In testimony ivhereoflhereto affix my sig- 1'

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