US155087A - Improvement in hot-air engines - Google Patents

Description

2 Sheets-*Sheet 1.,

1. HmscH. Hot-Air Engines.

Patented sepi.15,'1874.

No.l55,0 87.

2 Sheetsf-Sheet 2. HIRSCH.

Hot-Air Engines. N0. 155,087. Patented Sept.'15, 1874.

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UNITED STATES PATENT OFFICE.

JosEFE Friesen, OF LYoNs, FRANCE.

IMPROVEMENT IN HOT-AIR ENGINES.

Specification forming part of Letters Patent No. 155,087, dated September 15, 1874, application filed May 25, 1874.

To all whom it may concern'.-

Be it known that I, JOSEPH HIRscH, of Lyons, Department of the Ithone, France, have invented certain Improvements in Hot- Air Engines, of which the following is a specification:

The object of my invention is an improved engine in which to utilize, as a motive power,

the elastic force of hot air. I attain this object by causing the air to pass alternately back and forth from one cylinder to another through a passage or regenerator, in which an extensive heating or cooling surface is obtained in a small compass, the air being intensely heated and expanded by liquid or gaseous fuel in one cylinder, and cooled in the other; or being similarly treated on opposite sides of the piston of a single cylinder, and being gradually cooled in its passage through the regenerator from the hot to the cold air chamber, Whilel on its return to the hot-air chamber or cylinder it is as gradually heated by the said regenerator, all as fully described hereafter, and as illustrated by the accompanying drawing, in which- Figure 1, Sheet 1, is a sectional elevation of my improved hot-air engine 5 Fig. 2, Sheet 1, a side elevation; Fig. 3, Sheet 2, an end elevation; Fig. 4, Sheet 2, a plan view; Fig. 5, Sheet l, a sectional plan on the line 1 2, Fig. l; Fig. 6, Sheet l, a detached view of part of Fig. 5 Fig. 7, Sheet l, an enlarged view of part of the apparatus.

On reference to Figs. 1 to 6, inclusive, K represents the frame of an engine, to which are secured two cylinders, A and H, the former, which is the hot-air cylinder, being vertical, and the latter or cold-air cylinder inl" clined. The upper end of the cylinder A communicates with the outer end of the cylinder H through a passage, a, regenerator J, and passage b, which will be more particularly referred to hereafter. The upper portion of the cylinder A consists of a body, B, of refractory material, surrounded by a sheetmetal casing, B1, and the portion C of the piston C is also of refractory material, as are also the Walls a.' of the passage a, and walls I of the regenerator. The pistons C and G of the cylinders A and H are connected by rods D and F to cranks on the main shaft E of the engine, which is provided with a fly-wheel. (Not shown in the drawing.) The generator J consists of a net-work of refractory elements, through which the air is caused to pass in its passage from one cylinder to the other.

These elements consist, in the present infractory material, of the character illustrated in Figs. 5 and 6, arranged closely together, with spaces between them for the passage of the air, the object being to obtain as great an extent of heating and cooling surface as possible in a small space.

The refractory bars or plates can be made of earthenware, compressed magnesium, porcelain, or other analogous material; or they may be replaced by asbestus or Wire net-Work.

In some instances I prefer to subdivide the interior of the regenerator into several distinct vertical compartments, in order to diminish the length of the refractory bars, and thus increase their strength.

Within the passage b, beneath the regenerator, is a segmental valve, bl, provided with a handle, b2, by the movement of which the valve can be caused to close more or less of the passage, and thus regulate the speed of the engine.

An air-pump, L, Figs. 1 and 4, is attached to 011e side of the cylinder A, and is operated from the main shaft E of the engine through the medium of gear-wheels d and d', a crank, c, and connecting-rod L. This pump communicates with the passage b through a pipe, e, Fig. 3, and its object is to supply fresh air to the cylinder H to take the place of the con- /sumed air, which is periodically expelled.

The heat is kept up in the engine by gaseous or liquid fuel, Which is forced into the cylinder A by a pump, M, and there ignited. If gaseous fuel is used, it is generated by the vaporization of hydrocarbon in any Wel1-kn0wn form of apparatus, and is supplied to the pump through a pipe, j, Figs. 2 and 3, and is forced from the pump through a valve-chest, M2, pipe jl, and box f2, filled with Wire net-Work, into the upper portion ofthe cylinder A.

The pump M derives its movement from the piston G of the cylinder H through the medium of the following mechanism: The pistonrod of the pump is connected, by a rod, M1,

stance, of groups of thin plates or bars of re .and adjustable block f, to the arm g of a rockter, is arranged directly beneath the cold cyl-A inder H, as shown in Fig. 1, and communicates with the latter intermittently through a passage, k, the upper portion of the said chamber above the water-level being maintained at a pressure which varies in accordance with the desired speed of the engine. A small pump, P, Fig. 2, operated by a rod, p1, connected to an arm, p2, of the above-mentioned rock-shaft 7L, forces water through a pipe and sprinkler, Z, Fig. 1, into the cylinder H, for the purpose of cooling the air therein; and this water, together with the consumed air, is carried oif from the cylinder by the passage 7c into the chamber N at every stroke of the pump, owing to the action of a projection, O2, on the pump-rod p1, which strikes a springrod, O1, and thus operates a valve in a box, O, with which the said passage k communicates.

The operation of the engine is as follows: The temperature of the' cylinder A is first raised to the required degree by forcing first a current of hot air, and then gas or other Haines, through an opening, B2, with which the said cylinder is provided at the top. The pressure-reservoir N is next filled with water up to the opening m of the escape-valve fn,

Fig. l, which will be more particularly referred to hereafter, the stroke of the gaspump M is regulated by an adjustment of the slide f, Fig. 2; the fly-wheel is turned one or more times, in order to reciprocate the pistons, and the operation begins. A combustible gas or liquid is first injected into the cylinder A, Where it is consumed, highly heating the air already in the cylinder, and forcing down the piston. 0n the upward movement of the piston, the heated air passes through the regenerator J, which extracts a large proportion of the heat, and into the cylinder H, where the injected water reduces its volume, causing a partial vacuum, and operating the piston Gr. By these successive movements of the air, submitted alternately to great variations of temperature, the pistons are operated, the result of the varying pressures being a uniform reciprocating movement of the said pistons, and a positive rotary movement of the engine-shaft E. The air-pump L, before mentioned, supplies fresh air to replace that which is heated and expanded, and partly consumed at each revolution of the engine, and forced out of the cold cylinder through the passage k. As this consumed air, as well as the water of injectionfrom the cold cylinder, is continually stored up in the pressurereservoir N, it is necessary that the latter should be provided with an escape-valve, by which a uniform pressure can be maintained, and the said pressure regulated in accordance with the required speed of the engine. For this purpose I employ a valve, n, opening outward, and contained within a box, Q, which has a passage, m, communicating With the interior of the pressure-reservoir. The valve is maintained in its seat by a spring, n2, on a rod, nl, the pressure of which is regulated by a nut, a3. (See Figs. l and 7 The nut, rod, and spring are forced upward by a forked bellcrank lever, R, Fig. 3, acted on in one direction by a spring, n4, and in the opposite direction by a centrifugal governor, R1, which derives its movement from the engine-shaft E through two pulleys, R2 and R3, and a connecting-belt.

When the pressure in tbereservoirNexceeds the proper amount vthe valve a will be opened automatically, and will permit the gas and water to escape through the opening m1 and pipe m2 until the pressure has been relieved; and by means of the above-described governor I am enabled to regulate the speed of the engine by allowing an escape of pressure from the reservoir N when the speed is too great, and by permitting the pressure to increase when the speed of the engine slackens. For instance, if the speed increases, the governor will so vibrate the bell-crank lever It, Fig. 3, as to relieve the spring u2, and consequently give freer play to the escape-valve n. If, on the contrary, the speed slackens, the lever R will be vibrated in the opposite direction, which will compress the spring n2, and thus maintain the valve more firmly in its seat.

It is necessary that the lower portion of the cylinder A as well as of the piston C, which are of cast-iron, should be maintained at a comparatively cool temperature; and for this purpose I form an annular water-chamber, A', in the said cylinder, surrounding the piston, and pack the cylinder above and below this chamber with metallic packing p, to vprevent leakage. (See Fig. l.) Water continually vcirculates in the chamber A', and is supplied from the reservoir N through a pipe, q, Fig. 3,

which communicates with an elevated reservoir, S, the latter having a pipe, q1, leading to the chamber A', from which the water is conducted off through a pipe, g2, communicating with the waste-pipe g3 of the reservoir S.

Although I prefer to inject cold Water into the cylinder H at a moment determined by the stroke of the piston G, for the purpose of absorbing the heat which results from the compression of the air, I can substitute other equivalent cooling apparatus, arranged in the channel b beneath the regenerator, or I can cause cold water to circulate around the exterior of the said cylinder H.

In the engine above described the interior Vpressure is always greater than that of the external air, and it is necessary therefore to use an air-pump, L; but, in some instances, I can simplify the apparatus by reducing the pressure, and dispensing with the air-pump,

`pressure-reservoir N, and Water-injector, the fresh air necessary for the support of combusscribed, of the cold cylinder H, passage k, automatically-operated Valve, and the pressure-reservoir N.

4. The combination of the lower metallic portions of the cylinder A, its piston, and the annular coolingchamber A', through which a circulation of cold Water is maintained, as described.

5. Thecombination of the cylinder H, outl let m, reservoir N, and its spring-valve n, all substantially as and for the purpose described.

In testimony whereof I have signed my name to this specication in the presence of two subscribing witnesses.

JOSEPH HIRSCH.

Witnesses EMILE RICHARD, GH. F. THIRION.

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