US1913593A - Process and apparatus for charging explosion turbines - Google Patents

Description

F. HOFMANN June 13, 1933.

PROCESS AND APPARATUS FOR CHARGING EXPLOSION TURBINES Filed Aug. 6, 1928 2 Sheets-Sheet l O llllfrlllfllllIdllfilllllll'll!Ilill'll I 1/ If/ Ill/l I I 1/ I! I I /////l June 13, 1933. F. HOFMANN 1,913,593

PROCESS AND APPARATUS F011 CHARGING EXPLOSION TURBINES Filed Aug. 6, 1928 2 Sheets-Sheet 2 Fnam FUZL PUMP r7 TTO/PNE/S Patented June 13, 1933 PATENT OFFICE nrnnmcn nommr, or MuLnnm-on-rnE-auna, GERMANY, assrenoa 'ro noLz;

WARTH GAS TURBINE 60., OF SAN FRANCISCO,

' DELAWARE PROCESS AND APPARATUS FOR CHARGING EXPLOSION TUBBINES Application filed August 6, 1928, Serial No.

My invention relates to explosion turbines and its object is to reduce the time required for the chargin of explosion turbines in order that the in ividual explosions may follow each other more rapidly, thereby increasing the work performed in each unit of time, or on the other hand, reducing the size of the machine for a given capacity.

It has been the practice heretofore in the operation of explosion turbines to effect the charge of the elongated combustion chamber by means of air and fuel which are introduced at one side, i. e. the inlet side, the discharge occurring through the opening of a nozzle valve located at the other side, i. e. the exhaust side of the elongated cylindrical or pear-shaped explosion chamber. After the explosion has taken place it is necessary to remove the residual combustion gases through the nozzle valve. This nozzle valve is necessarily or rather small cross-section and as a consequence considerable time is required to effect the discharge of these residual gases. It has already been proposed to shorten this time by arranging an additional discharging element in proximity to the nozzle valv'e, which element thus performs the function of an auxiliary exhaust mechanism whose d imensions however, on account of its structural connection with the nozzle valve, must be relatively small, so that the reduction in the time required for scavenging the chamber due to such auxiliary mechanism cannot be very great.

The present invention proceeds along a different course. In accordance with my invention the expanded residual combustion gases are given a free exit side of the combustion oham er where a considerably larger cross-section of opening can be afforded. It may be left to the discretion of the designer whether or not this opening upon the inlet side is to be exposed simultaneously with the known or usual opening or openings upon the exhaust side. It is also a matter of choice whether or not only the expanded combustion gas residue is driven out through this exposed opening at the inlet side or coolin scavenging air is permitted to follow such ischarged residual gas.

ath at the inlet 297,619, and in Germany August 15, 1927.

In the accompanying drawings which show by way of example a form of my invention without defining its limits, and represent diagrammatically the conduit ends of an explosion chamber with the appurtenant valve controlling mechanism and the associated nozzle located adjacent the turbine wheel, Fig. 1 shows my novel discharge mechanism in position during the charging of the ex plosion chamber, the same being shown in central longitudinal section; Fig. 2 is a similar view showing the position of the parts during the work-performing explosion and expansion of the combustion gases; Fig. 3 il lustrates in longitudinal section the osition of my novel mechanism during the isplacement and discharge of the residual gases; and Fig. 4 is a diagrammatic view,.partly in section, illustrating the control mechanism for timing the operation of the valves.

The explosion chamber is designated by the letter a while I) shows the air valve, 0 the fuel valve, and d the discharge valve. Fresh scavenging and charging air is introduced throug conduit 6 and fuel through 9. The discharge of the expanded residual gases occurs through the conduit f. The nozzle valve is shown at h, the nozzle at 2' and the turbine blades at k.

In the position of the parts shown in Fig. 1 the combustion chamber is filled witht-he combustible charge under appropriate pres? sures through the valves 6 and 0. The noz: zle valve h and the discharge valve d are closed during this period. After the closing of the inlet valves 6 andc the charge is ignited and immediately thereafter the nozzle valve his opened (Fig. 2). The gases escape at high pressure through the nozzle and through the turbine wheel, performing work as they pass through the latter until they have expanded to the point which is most favorable for the efficiency of the turbine. The air valve 6 and discharge valve 03 are then opened at about the same time. The expanded gases are then pushed out both through the nozzle valve h and through the discharging mechcanroama, a oonromrrou or anism (1 into the nozzle ring and into the discharging conduit 7, respectively, by means of the air. The chamber becomes filled with air which partly pushes the residual gases before it and partly displaces the same along the walls as they travel in counter-current relation through the valve d (Fig. 3). The greater part of the residual gases thps escapes through d because the cross-section of the opening at d and of the conduit 7 1s essentially greater than that of i and for the further reason that the turbine wheel opposes a considerable resistance to the rather slowly flowing residual gases. For this reason it is quite immaterial at what tlme the nozzle valve is closed during this displacement process. The residual gas discharging mechanism d is preferably so located, as shown in the drawings, that it is out of the direct, initial ath of the incoming stream of air charged y the air valve b, so that the air stream cannot make a short cut to such dischar ing mechanism but must first traverse and fill the combustion chamber. After the residual gases'have been completely d1splaced and replaced by fresh air in the manner described, the discharge valve (1 and also the nozzle valve h, should the latter have been kept open to this point, are closed and at the same time the fuel valve 0 is opened. It is immaterial so far as the present invention is concerned, whether the fuel valve 0 1s opened after the air valve has been closed, or is opened while such air valve is stlll open; it is preferred, however, to open the fuel valve while the air valve is still open, as indicated in Fig. 1.

For the sake of clearness of explanatlon of the invention it has been assumed that the use of air, under different pressures, i. e. lower pressure scavenging air and higher pressure charging air (customary in the present operation of turbines), has been dispensed wlth and that air at only one pressure is used. It

. is immaterial so far as the present process is concerned whether the fuel employed is liquid or gaseous.

Suitable mechanism must be provided to effect the opening and closing of the discharging mechanism and of thealr charging mechanism at the proper instants. The embodiment disclosed is adapted to be provided with an oil ressure controller of the type shown in the patent to Holzwarth 0. 877,194, which can be made to operate both the air charging and the residual gas dis-.

charging mechanism. The oil under pressure from such controller is conducted through ipe lto the air charging mechanismand to t e discharging mechanism by the pipe m. The return of these mechanisms to closed position is effected by means of the springs 'n and 0 respectively.

A satisfactory control mechanism for the valves of the explosion chamber is illustrated schematically in Fig. 4. The oil conduits l and m are connected with a rotating distributor p for the pressure fluid in such 8.

manner that at the instant in which the valves 6 and d are tabs 0 ned, such pressure fluid is charged into sai conduits Z and m and operates the valves b and 41 through the pistons associated with the stems of such valves and against the action of the s rings n and o. A separate section of the distributor 1) serves for controlling the nozzle valve 1:. throu h the conduit 9. The fuel is conducted to the fuel valve 0 through conduit 9 at the proper instant by a suitable fuel pump (not shown). The distributor may be of the type described in detail in United States Patent No. 877 ,194. The distributor p and its pump 1' ma be driven by a motor 11 independently o the turbine shaft.

It is of advantage to locate the air valve within the discharge mechanism, as shown, so that a central current of air travelling in the direction of the nozzle displaces a counter-current annular stream of gases travelling along the walls of the combustion chamber toward the inlet side thereof and ultimately discharged through the valve d.

Variations may be resorted to within the scope of the claims Without departing from the spirit of the invention.

I claim:

1. In an elongated explosion chamber suitable for use in explosion turbines, the combination of a main outlet valve at one end of the chamber adapted to discharge high pressure combustion gases generated in such chamber for work outside the same, means for opening and closin said valve, an air valve at the opposite en of the chamber arranged to charge a central, cylindrical stream of air into the chamber, means for opening and closing said air valve, fuel charging mechanism at said opposite end of the chamber, means for conducting fuel periodically to said mechanism, an auxiliary outlet at said opposite end of the chamber, and meansfor openin and closing the same, the control means or said air and auxiliary outlet valves operative to open the latter substantially simultaneously following the expansion of the combustion gases through the open nozzle valve, whereby the residual gases are forced by said central, cylindrical stream of air to travel in the form of a hollow cylinder along the walls of the chamber toward and through the auxiliary outlet counter to the direction of flow of said air.

2. In an explosion chamber suitable for use in explosion turbines, the combination of air and fuel char ing valves located at the inlet end of said 0 amber, a nozzle valve at the outlet end of said chamber, a residual gas discharging valve located at the inlet end of said chamber, said residual gas discharging valve surrounding the air charging valve, and control devices for o ning and closing said valves at predetermined instants, said control devices operative to hold said air charging and said residual gas discharging valves open for overlapping periods so that the enterin air effects discharge of at least a part of t e residual gases through said 5 residual gas discharging valve.

1 outlet end of said chamber,

discharging valve located at the inlet end of 3. In an explosion chamber suitable for use in explosion turbines, the combination of air and fuel charging valves located at the inlet end of said chamber, a nozzle valve at the a residual gas said chamber, said air charging valve being concentrically positioned within said residual gas discharging valve, and control devices for opening and closing said valves at predetermined instants, said control devices operative to hold said air charging and said residual gas discharging valves open for overlappin periods so that the enterin air effects disc arge of at least a part 0 the residual gases through said residual gas discharging valve.

4. In an explosion chamber for explosion turbines, the combination of air and fuel charging valves located at the inlet end of said chamber, a nozzle valve at the outlet end of said chamber, a residual as discharging valve located at the inlet end of said chamher, said air and fuel charging valves being positioned concentrically one within the other and both within said discharging valve, and control devices for openin and closing said valves at predetermined instants, said control devices operative to hold said air charging and said residual gas discharging valves open for overlappin periods so that the entering air effects disc arge of at least a part of the residual gases through said resldual gas discharging valve.

5. In an explosion chamber suitable for use in ex losion turbines, the combination of air and uel char ing valves located at the inlet end of said 0 amber, a nozzle valve at the outlet end of said chamber for discharging the combustion ases following the explosion of a fuel and a1r charge, a residual s discharging valve located at the inlet en of said chamber, and control devices for opening and closing said valves at predetermined instants, said control devices operative to hold said air charging and said residual gas discharging valves open for overlapping periods so that the enterin air eflects discharge of at least a part of the residual gases through said residual gas discharging valve, such residual gas dischargin valve being positioned out of the initia path of the stream of air admitted by said air charging valve.

- FRIEDRICH HOFMANN.

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