US2479143A

US2479143A - Gas turbine

Info

Publication number: US2479143A
Application number: US567042A
Authority: US
Inventors: Jr Samuel W Traylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-12-07
Filing date: 1944-12-07
Publication date: 1949-08-16
Anticipated expiration: 1966-08-16

Description

s. w. TRAYLoR, JR I 2,479,143

Aug. 16, 1949.

GAs `TURBINE 3 Sheets-Sheet 1 Filed Deo. 7. 1944 Aug. 16, 1949.

s. w. TRAYLOR, JR

GAS TURB'INE :s sheets-sheet s Filed Dec. 7, 1944 i grwmvfo'b m43 sa" l Patented Aug.` 16, 1.949v

UNITED STATES APATENT OFFICE Application December 7, 1944. Serial No. 567,043

(Cl. 60-41l 6 Claims.

This invention relates to turbines of the general type in which a combustible mixture of gases is burned to create a rapid expansion and the resulting gaseous products of combustion are used for driving a turbine wheel.

Heretofore in gas turbines of this general type it has been customary to alternate the explosions and the cooling processes in order that the working parts of the turbine-which should not exceed a temperature of 1,000 degrees F.-would not deteriorate from excessive heat.

The present invention has for an object to overcome the above disadvantages by providing a turbine so constructed and arranged as to be efciently cooled while avoiding the necessity of diluting the combustion gases with the cooling air or alternating the explosion and cooling processes. In accordance with the invention this object is accomplished by simultaneously pass-A ing the combustion gases and fresh cooling air through the turbine wheel in separate streams so as to obtain substantially the full cooling eiiect of the air for cooling the wheel and without significantly lowering the temperature of the combustion gases. By the term fresh air is meant air which is substantially uncontaminated by the products of combustion.

Another object of my invention is to providey in a turbine of the above class a series of combustion chambers circumferentially spaced about the turbine wheel adapted for periodically firing mixtures of combustible gases, and discharging them against the blades of the turbine wheel and for introducing fresh charges of combustible mixtures into the chambers. Y

A further object of my invention a turbine of the above class so constructed and arranged that the hot combustion gases are periodically discharged through certain areas of theA 'through a portion of the turbine; g Figure 4 is a detail view of a portion of the turbine wheel;

Figure is a detail cross-sectional view on the is to provide line I-B of Figs. 3 and 4 of one of the spokes of the turbine wheel;

Figure 6 is a schematic view of the complete turbine assembly.

The turbine shown in the drawings comprises a bearing block I supported on a pair of upright standards 2 footing on a base block 3. Upon one end of shaft I is mounted a turbine wheel 5 of openwork construction, the other end of the shaft (not shown) serving as a take-'off for mechanical power, such for example as may be usedv for driving an electric generator.

The turbine wheel comprises a hub 6 keyed to the shaft I and a series of spokes 1 radiating therefrom fashioned in theform of vanes which during rotation of the wheel function as fans for drawing air through and over the turbine wheel. Supported upon the spokes 1 is a pair of concentrically spaced rings 8 and 8a defining between them an annular passage 9. The opposed faces of the rings are inclined with reference to 'each other, as best shownin Fig. 3, to

define a passage 9 which expands from the forward to the rear sides of the turbine wheel. Located intermediate the rings and projecting a short distance radially beyond the outer ring 8 is aseries of circumferentially spaced-apart blades III which are disposed at an angle to the plane of the turbine wheel. The spaces between adjacent turbine blades define open-ended passageways to allow the ow of air therealong. The circumferentially projecting portions I0a of the blades I0 serve to draw air through the turbine wheel and cool the outer periphery of the wheel.

Forming a casing surrounding the periphery of the turbine wheel but spaced a short distance therefrom is a hollow annular 'bustle pipe II forming an air chamber to which air under pressure is supplied from a pipe I2 leading from the discharge side of a blowerlB (Fig..6)

-The bustle pipe II is supported adjacent its lower circumference ln a cradle 3a attached to the base block 3. A i'iat forwardly disposed wall I3 of the bustle pipe abuts and is bolted to the flat rearwardly disposed face of a circular plate I4.v Cast integral with the plate Il yand projectingoutwardly from its forwardly disposed face at circumferentially spaced points -thereabout is a series of combustion chambers I5, and leading -off radially from each chamber is a nozzle I0 terminating closely adjacent the turbine blades l0 that are located intermediate the rings 8 and 8a on the turbine wheel. The nozzles, the discharge ends of which lie within the periphery--` or more precisely` the horizontally extendedperiphery-of the ring of turbine blades, are preferably directed at an inclination with respect to the plane of the turbine wheel so as to cause an angular impingement of combustion gases against the turbine blades. A fuel injector I1 for introducing a combustible liquid, such as a light or heavy hydrocarbon oil, into the combustion chamber, and an ignition device I8. here represented as a spark plug, are suitably associated with each combustion chamber for fueling and ring the chamber.

In order to admit air from the bustle pipe into each combustion chamber, ports I9 are provided in the plate I 4 suitably arranged so as to aiord communication between the bustle pipe and the circumferentially spaced series of chambers. The ports I9 of each chamber are adapted to be covered by a valve disk 20 slidably mounted on a pin 2| supported in the plate I 4. The disks are biased toward port-closing position by a compression spring 22 encircling the pin and exerting pressure between the valve disk and a head on the pin, the force of the spring being such as to yield and maintain the valve open under the normally greater pressure of air in the bustle i p gen operation, therefore, the valves are normally maintained open, and are only momentarily closed by explosions within the chambers.

Fastened to the outlet side of the casing, that is, to the rear side of the bustle pipe, is an exhaust pipe 23 of generally bell-shape, the enlarged end of which corresponds in size to the inner diameter of the bustle pipe II while the smaller discharge end of the exhaust pipe opens gases are made of heat-resistant metal or metals to the atmosphere for the discharge of the coml` bustion gases passing through the turbine wheel. The outlet end of the exhaust pipe is preferably provided with a muiller, indicated at 24 (Fig. 6).

Liquid fuel is sprayed into each combustion chamber by the injector l1 operated at periodic intervals by a fuel pump actuator P (Fig. 6), with which is associated a series of pumps P', one for each combustion chamber, so as to produce a combustible mixture with the air flowing into the chamber through the ports I9. For periodically sparking the ignition devices I8 in timed relationship to the operation of the fuel injectors, an electrical distributor D is provided. As schematically indicated in Fig. 6, the pump actuator P and distributor D are coupled by a shaft 24 for synchronized operation and are driven from the shaft I through a transmission 25. Fuel lines 26 connect the individual pumps P with the injectors I1, and the distributor D is connected by conductors 21 in electrical circuit. As the distributor rotates. all the points may be simultaneously closed so as to cause explosions in the combustion chambers at the same time, or the points may be closed in sequence so as to produce staggered or sequential explosions in the combustion chambers. The pump actuator P and the distributor D are well known in the art and of themselves constitute no part of my invention. The compressor or blower B for supplying air to the bustle pipe II likewise is driven from shaft l through a transmission chain 21a. A hood 28 closes the forward or inlet side of the casing, including the combustion chambers I5, and the air for cooling the turbine wheel is deliveredV into the hood under pressure from a duct 29 'connected to the discharge side of the blower B.

It will be understood that the combustion capable of withstanding the temperatures developed in the turbine.

In the operation of the turbine just described, air delivered to the hood 28 by the blower B will pass through the turbine wheel and will be discharged through the exhaust pipe 23. 'I'his strong current of fresh air in flowing through the turbine wheel and through the turbine blades in the exposed areas between adjacent combustion chambers carries away the heat and effectively lowers the temperature of the turbine Wheel. Fuel is periodically injected into each combustion chamber by the injector I1 and forms a combustible mixture with the air flowing from the bustle pipe II into the chamber through the inlet ports I9 against the pressure of the springpressed disk valve 20. When the ignition device lres to explode the charge within the chamber, the combustion gases are forced out through thenozzle I6 under high pressure and impinge against the blades 9 of the turbine wheel to impart rotation to the wheel. At the same time, the force of the explosion in the chamber, by reason of the increased gas pressure generated in the chamber, momentarily forces the valve disk 20 to its seat, closing the ports I9. The combustion gases pass through the turbine blades and are swept along with the current of cooling air, eventually discharging through the exhaust pipe 23.` Following each explosion the valve disk 20 again opens under the 'pressure of air inthe bustle pipe to allow a fresh supply of air to enter the combustion chamber, and the cycle is repeated.

'I'he distributor is preferably arranged so as to cause firing of the cylinders in sequential order so that a succession of impulses is continuously transmitted to the turbine wheel, thus applying a torque thereto; however, the timing may be so arranged that some, or even all, of the explosions occur simultaneously.

From the foregoing it will be seen that torque is transmitted to the turbine wheel by discharging hot combustion gases intermittently and with explosive violence against the turbine blades, while cold air in a continuous stream ilows through and around the turbine wheel without any appreciable dilution of the combustion gases during the gas expansion phase.

The turbine may be adjusted to varying load conditions by regulating the interval between fuel injections, since the lighter the load the fewer the impulses necessary to drive the turbine wheel. The constantly flowing cooling air through and around the 'turbine wheel and the control of the number of explosions per minute afford means for maintaining the temperature of the turbine wheel below that at which rapid and destructive deterioration occurs.

Other firing means than the electrical spark ignition described above may be employed. For example, the size of the combustion chamber and its cooling properties (both internal and external) may be so designed that no external ignition is required, the residual heat of the combustion chamber being employed to ignite the explosive mixture of gases in the chamber.

It will be understood that the simplified arrangement illustrated in Fig. 6 is solely for the purpose of more clearly disclosing the cooperative relationship of the parts and that other arrangements may be adopted and other adiunctive gaat.

described above without departing from the spirit of the invention as set iorth in the I ollowln claims:

I claim:

1. A gas turbine comprising a turbine wheel having blades thereon, a series or spaced-apart combustion chambers mounted adjacent the turbine wheel in circularly spaced relation, nozzles..

communicating with the combustion chambers and terminating adjacent the turbine blades, fuel injectors operatively associated with the combustion chambers, a bustle pipe mounted adjacent the series of combustion chambers and providing a source of air under pressure, said bustle pipe surrounding the turbine wheel in spaced relation thereto so as to provide a casing having substantiallyunobstructed inlet and' outlet openings in advance vof and to the rear oi the turbine wheel to allow the free ow of air therethrough, air ports opening from the bustle pipe into the combustion chambers, valves for closing the air ports but being normally maintained open under the pressure of air in the bustle pipe, ignition means for periodically exploding charges of combustible mixtures within the combustion chambers so as to discharge the combustion gases through the nozzles and against the blades, and ian blades driven by the turbine wheel for inducing a iiow of cooling air through the blades of the turbine wheel.

2. A gas turbine comprising a turbine wheel having blades thereon, a series of spaced-apart combustion chambers mounted adjacent the turbine wheel vin circularly spaced relation, nozzles communicating with the combustion chambers and terminating adjacent the turbine blades, fuel injectors operatively associated with the combustion chambers, a bustle pipe mounted adjacent the series of combustion chambers and providing a source of air under pressure, said bustle pipe surrounding the turbine wheel in spaced relation thereto so as to provide a casing having substantially unobstructed inlet and outlet openings in advance of and to the rear of the turbine wheel to allow the free ow of air therethrough, air ports opening from the bustle pipe into the combustion chambers, valvesfor closing the air ports but being normally maintained open under the pressure of air in the bustle pipe, ignition means for periodically exploding charges of combustible mixtures within the combustion chambers so as to discharge the combustion gases through the nozzles and against the blades, and fan blades driven by the turbine wheel for inducing a now of cooling air through the lblades of the turbine wheel, said combustion chambers being located beyond the periphery of the turbine wheel and said nozzles being directed generally radially but at an angle with respect to the plane of the turbine wheel.

3. A gas turbine comprising a turbine wheel having blades spacedin a circumferential direction thereon, a combustion chamber in communication with said turbine wheel, a discharge nozzle communicating with said combustion lchamber land being directed toward and terminating adjacent said turbine wheel blades., conduit means for continuously supplying pressure air to said combustion chamber, an air port opening from said conduit means into said combustion '6 chamber, valve means associated with said air port, said valve means being adapted to be temporarily closed byexplosion pressure within the combustion`chamber but being normally open whereby air suppliedv to said chamber between explosions may pass through said'chamber and through said blades, means for periodically supplying i'uel to said combustion chamber, ignition means for exploding the periodically supplied iuel charges, and independent means for causinga distinctA ilow' of cooling air through seid turbine wheel blades. ,l 4. A gas turbine comprising a turbine wheel having bladesspaced in a circumferential direcytion thereon, a plurality of circumferentially spaced combustion chambers in communication with said turbine'wheel, discharge nozzlescommunicating with said combustion chambers and being directed toward and terminating adjacent said turbine wheel blades, conduit means for continuously supplying pressure air to said combustion chambers,.air ports opening from said conduit means into said combustion chambers, valve means associated with each oi said air ports, said l spaced combustion chambers in communication with said turbine wheel, discharge nozzles communicating with said combustion chambers and being directed toward and terminating adjacent said turbine wheel blades, conduit means for continuously supplying pressure air to said combustion chambers, air ports opening from said conduit means into said combustion chambers, valve means associated with each of said air ports, said valve means being adapted to be temporarily closed by explosion pressure within the combustion chambers but being normally open whereby air supplied to said chambers between explosions may pass through said chambers and through said blades, means for periodically supplying iuel to said combustion chambers, ignition means for exploding the periodically supplied fuel charges,

' and independent means for causing a distinct ilow of cooling air through said turbine wheel blades, between said combustion chambers and said discharge nozzles.

6. A gas turbine comprising an openwork turbine wheel having blades spaced in a circumferential direction thereon, a plurality oi' circumferentially spaced combustion chambers in combers and through said blades, means for periodically supplying fuel to said combustion chambers, ignition means for exploding the periodically supplied i'uel charges, and fan means associated with said turbine wheel for causing a distinct ow of cooling air through said turbine wheel and turbine wheel blades.

SAMUEL W. TRAYLOR, Jn.

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

UNITED STATES PATENTS Number Name Date 1,319,752 Brown Oct. 28, 1919 1,340,563 Schmid May 18, 1920 Number Number