US2435042A

US2435042A - Plural fluid turbine combining impulse and reaction blading

Info

Publication number: US2435042A
Application number: US510698A
Authority: US
Inventors: Johansson Johan Erik
Original assignee: Goetaverken AB
Current assignee: Goetaverken AB
Priority date: 1942-11-09
Filing date: 1943-11-17
Publication date: 1948-01-27
Anticipated expiration: 1965-01-27

Description

PLURAL FLUID TURBINE COMBINING IMPULSE AND REACTION BLADING Filed Nov. 17, 1943 FIG.1.

FIG.3

@atented J W fiQ 2,ll35,i id2 runner. FLUD renames co PULSE REACTIUN B F Application November 17, 1943, Serial No. 510,698

r In Sweden November 9, 1942 Section 1, Public Dew 690, August 8, 1946 Patent expires November 9, 1962 5 Claims. (01.60-49) This invention relates to a turbine for expanding working fluids of diflerent pressures.

The invention has for its main object to effect as rapidly as possible such a great decrease of the pressure of the high pressure fluids that said blue driven by exhaust gases from an .internal combustion engine that the turbine eillciency is practically independent of variations in the load on the engine.

These and further objects are attained by constructions illustrated in the annexed drawings.

in which:

Figure 1 is an axial section of an embodiment; Figs. 2 and 3 are sections of systems of nozzles or guide vanes and moving blade rims, these sections being taken on the lines 2 2 and 3-3, re-

spectively, in Fig. 1.

The turbines shown are intended to be driven by exhaust gases from an internal combustion engine, said exhaust gases being supplied to the turbine at two or more different pressures.

The invention is based on the known fact that moving blades of the impulse type require a considerably lower blade peripheral velocity than blades of the reaction type. Consequently, if blade rims intended for motive fluids of high pressures are provided with moving blades of the impulse type, and if blade rims for low pressure fluids are provided with blades 01' the reaction type, a favourable turbine efiiciency can be obtained both in the turbine portion driven by the high pressure fluid and in the portion driven by the low pressure fluid.

If the turbine is intended to be driven by exhaust gases from a motor, which exhaust gases are admitted at diflerent pressures, there exists another reason for providing that portion of the turbine which is to be charged with low pressure gas, with moving blades of the reaction type. At

variations 0! the load on the motor, the drop-in temperature of the low pressure gases is varying relatively more than the drop in temperature of the high pressure gases. A reaction turbine is much less responsive to such variations than an impulse turbine. Consequently, the eiliciency of the reaction turbine is influenced to a small extent only by variations in the load on the motor.

In-Fig. 1. there is shown embodiment of a turbine adapted to'be driven by means or gases of are of the reaction type.

different pressures and having concentric admission means for the high pressure and low .pressure gases. Numeral l1 indicates the inlet for the low pressure gases and iii the inlet for the highpressure gases. Said inlets are separated from each other by means of a partition wall l9 forming two admission chambers 20 and 2 I. 'The admission chamber 20 for the low pressure gases is located outwardly of the admission chamber 2i for the high pressure gases.

The high pressure gases are passing through a nozzle or guide vane system 22, a moving blade rim 23, a guide vane rim 24, and finally through a further movingblade rim 25 which is common to the high pressure and the low pressure gases. The last named gases are admitted to the moving blade rim 25 by means of a nozzle or. guide vane system 26. The outlet from the turbine is indicated at 21.

As will be seen from Figs. 2 and 3, the moving blades of the blade rim 23 are of the impulse type, while the moving blades of the blade rim The high pressure gases are consequently working on a reaction blade system in addition to an impulse blade system. The heat drop is divided amongst the impulse blades and the reaction blades in a manner such that the gas pressure on the reaction blades common to. the high pressure and low pressure gases will be substantially constant along the whole lengths of the blades, that is, the pressure prevailing in the intermediate space 28 will be the same behind the impulse turbine portion and behind the guide vanes in the reaction turbine portion for the low pressure gases. Since the high pressure gases are passing two moving blade rims one of which is provided with impulse blades, whereas the low pressure gases are passing through one blade rim only having blades of the reaction type, peripheral velocities will be obtained which ensure favourable eniciencies both for the low pressure portion and the high pressure portion of the turbine. v

The invention is obviously not limited to the. embodiment thereof described and illustrated in the drawings, but may be modifled as to constructional details within the scope of the appended claims.

What I claim is:

1. In an elastic fluid turbine, a turbine wheel. a first blade rim system including moving blades substantially of the impulse type, a second blade rim system including moving blades substantially of the reactlontype, said moving blades being secured to said wheel, means for admitting high pressure working fluid to said first blade rim system, and means for admitting low pressure working fiuid to said second blade rim system, said first system having a smaller mean diameter than said second system, and the number of blade rims in said first system being greater than the number of blade rims in said second system, said blade rim systems being constructed and arranged to expand said high pressure fluid and said low pressure fluid, respectively, to substantially equal exhaust pressures.

2. In an elastic fluid turbine, a turbine wheel, a first blade rim system including moving blades substantially of the impulse type and moving blades substantially of the reaction type disposed in series after said impulse blades, a second blade rim system including moving blades substantially of the reaction type, said moving blades being secured to said wheel, means for admitting high pressure working fluid to said first blade rim system, and means for admitting low pressure working fluid to said second blade rim system, said first system having a smaller mean diameter than said second system, said blade rim systems being constructed and arranged to expand said high pressure fluid and said low pressure fluid, respectively, to substantially equal exhaust pressures.

3. In an elastic fluid turbine, a turbine wheel, a first guide vane rim, a first moving blade rim having blades substantially of the impuisetype, a second guide vane rim, said rim being arranged in series in the order named, a third guide vane rim located radially outwardly of said second guide vane rim, a second moving blad rim having blades substantially of the reaction type and being adapted to receive working fluid from said second and said third guide vane rims, means for admitting high pressure working fluid to said first guide vane rim, and means for admitting low pressure working fluid to said third guide vane rim, said blade rim, systems being constructed and arranged to expand said high pressure fluid and said low pressure fluid, respectively, to substantially equal exhaust pressures.

4. In an elastic fluid turbine, a turbine wheel, a first blade rim system including moving blades substantially of the impulse type and moving blades substantially of the reaction type disposed in series after said impulse blades, a second blade rim system including moving blades substantial- 1y oi the reaction type, said moving blades being secured to said wheel, means -for admitting high pressure working fluid to saidfirst blade rim system, and means for admitting low pressure working fiuid to said second blade rim system, said second blade system having its reaction blades common to the high pressure and low pressure working fluids, said blade rim systems being constructed and arranged to expand said high pressure fluid and said low pressure fluid, respectively, to substantially equal exhaust pressures.

5. In an elastic fluid turbine, a turbine wheel, a first blade rim system on said rotor including moving blades substantially of th impulse type and spaced moving blades substantially of the reaction type, a guide vane disposed in the space between said moving blades, a second blade rim system on said wheel including a second guid vane, said reaction type moving blades registering with said second guide vane so as to be common to both systems, means for admitting pressure working fluid to said first blade rim system, and means for admitting pressure working fluid to said second blade rim system, said blade rim systems being constructed and arranged to expand said high pressure fluid and said low pressure fluid, respectivel,y to substantially equal exhaust pressures.

JOHAN ERIK JOHANSSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 9 1,012,813 Chaleil Dec. 26, 1911 1,263,473 Schellens Apr. 23, 1918 1,428,925 Thomas Sept. 12, 1922 1,708,402 Schilling Apr. 9, 1929 2,258,794 Way Oct. 14, 1941 FOREIGN ,PATENTS Number Country Date 225,820 Great Britain Apr. 30, 1925 229,641 Great Britain Oct. 15, 1925 504,263 Great Britain Apr. 21, 1939 591,491 France Apr. 10, 1925 781,103 France Feb. 18, 1935