US2971924A - Apparatus for smoke generation - Google Patents

Description

Feb. 14, 1961 R. R. PETERSON APPARATUS FOR SMOKE GENERATION 2 Sheets-Sheet 1 Filed June 25, 1956 .akx NH INVENTOR A Eqyfi. [2 2275022 ATTORNEYS Feb. 14, 1961 PETERSON 2,971,924

APPARATUS FOR SMOKE GENERATION Filed June 25, 1956 2 Sheets-Sheet 2 INVENTOR BY ATTORNEYS United States Patent 2,971,924 APPARATUS FOR SMOKE GENERATION Roy R. Peterson, Rte. 2, Sterling, Va. Filed June 25, 1956, Ser. No. 593,775 1 Claim. (Cl. 252-359) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a method and means for smoke generation, and more particularly to a method and means whereby the exhaust gas from a gas turbine is used in generating said smoke.

Prior art smoke generating techniques usually consist of combining fog oil with the exhaust gas of an internal combustion engine, as for example either a gasoline or a diesel engine, and exhausting said combination to the atmosphere, said oil being vaporized by the heat of the exhaust. An alternative arrangement consists of a special apparatus of one form or another especially designed for the generation of smoke, such apparatus usually comprising means for combining fog oil with a substantial volume of moving air and igniting the combination, then exhausting said combination to the atmosphere. The use of exhaust gas from a reciprocating engine such as either a gasoline or diesel type has the disadvantage of failing to provide an adequate volume of moving gas, at a sufiiciently high temperature to bring about satisfactory vaporization of the fog oil; thus, this prior art method of smoke generation is not an eflicient smoke generating means. The use of a separate smoke generating unit, of course entails additional expense and requires a substantial amount of additional space; these factors are of particular significance where the smoke generating equipment is being utilized in a machine, such as a plane or boat that is already provided with some source of motive power, as for example a gasoline or diesel engine, since such special equipment takes up additional space and adds considerable weight. Furthermore, such separate units are usually fairly complicated and expensive, and present an added expense in the construction of a vehicle, as for example a boat.

It is an object of thi invention to overcome the disadvantages set forth above regarding the prior art smoke generators.

It is another object of this invention to provide a high temperature means of smoke generation, said means also providing a high rate of air flow.

It is a further object of this invention to utilize the exhaust gases from a gas turbine in the formation of smoke by the vaporization of fog oil.

It is still another object of this invention to utilize the exhaust gases from a gas turbine that is utilized in driving a landing-craft-type boat, for the purpose of generating smoke.

In accordance with this invention a source of fog oil is connected to suitable nozzles located in the exhaust ducts of a gas turbine utilized either on board a boat or the like for motive power; or for the operation of a fire pump. A suitable fog oil pump being located between a source of oil and the nozzles in the exhaust ducts.

Other objects and many of the attendant advantages 0 within the oil nozzles 20.

of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with of a nozzle utilized in the arrangement shown in Fig. 1.,

Referring now to the characters designate like out the several views, there is shown diagram of a preferred embodiment of the invention, including a plan view of the hull of a boat 8 partially br ken away and in section, said boat being propelled by a gas turbine 10 of suitable size. One example of such a boat is a landing craft of the LCVP type (Landing Craft Vehicles Personnel), said boat being propelled by a HP. gas turbine. The foregoing reference to a particular type of use for a gas turbine is, of course, given by Way of example only; either other boats or other vehicles of various size and type can also be propelled by a gas turbine of appropriate horsepower. In the embodiment shown in Fig. 1, a gas turbine 10 is mounted between the sides of a landing craft hull 8, and is covered by an enclosure 12. The gas turbine is provided with oppositely extending exhaust ducts 14, each of said exhaust ducts being faired into connection with an extension tube 16.

A pair of nozzles are mounted within each extension tube 16. One nozzle 18 is connected to a source ofwater, said water being sprayed into the exhaust line for purposes of cooling the exhaust gases slightly and also for preventing coking of the fog oil. The second nozzle 20 is utilized as a means for distributing the fog oil within the exhaust extension tube 16, said nozzle being connected by suitable piping 22 to a fog oil container 24. The fog oil is fed from the tank 24 into the nozzles 20 by means of a pump 26 located in the oil pipe lines 22.

Fig. 3 illustrates a form of the type of nozzle 20 utilized in distributing the fog oil into the exhaust lines 16. It is however pointed out that the nozzle shown in Fig. 3 is given by way of example only, and that any form .of spray nozzle or the like can be utilized for the same purpose. In addition to the exhaust extension tubes 16, there is connected to the engine compartment a pair of eductor pipes 28. the inner end of each being open to the atmosphere within the engine compartment. The eductors each extend outwardly from said compartment and through the hull of the boat or the like; than the respective exhaust extension tube 16 and concentrically spaced from said tube 16. The flow of the exhaust gases from the end of respective extension tubes 16 and through the eductor pipes 28 draws out the hot air contained within the gas turbine serving to lower the temperature in said compartment said hot air flowing around the exhaust extension tubes 16.

It is pointed out that in the smoke generating apparatus described above, a comparatively non-volatile petroleum oil is ordinarily used as a smoke producing material. The oil is vaporized by the high temperature of the gas turbine exhaust gases, and upon discharge into the atmos phere the vapor, thus formed, condenses into a persistent cloud of minute oil particles. The presence of the water vapor formed as the water moves out of the nozzle 18 serves not only to cool the exhaust gases but also serves to prevent, or at least minimize the formation of coke Furthermore, by virtue of the dampening eflfect of the steam formed in the exhaust pipe, the flaming or spontaneous combustion of the oil drawings, wherein like reference or corresponding parts through-- in Fig. 1, a schematic,

vapor, as it is discharged into the atmosphere, is prevented or at least minimized -It is pointed out that by virtue of the applicants invention', described above,ia' more efficient I formation of smoke is possiblethan is'the case when forming smoke by injecting oil into the exhaust passage of a reciproeating-type internal combustion engine, as for example, a gasoline or diesel engine. This is true due to the fact that the exhaust gases from a gas turbine are considerably higher in temperature than those from a reciproeating engine, and the quantity of exhaust air fiowv is approximately threeztimes greater for a gas turbine of a given horsepower, than for a reciprocating engine of like horsepower.

, a As' previously pointed out, even though the enclosed smoke generating arrangement used in conjunction with a gas turbine mounted on a beat, it is of coursequite' possible to use a gas turbine, in various types of installations, for smoke generating purposes, by utilizing the arrangement described above. The following figures show results of the use of a gas turbine operated, fire pump, said turbine being a Solar T-45 gas turbine:

(a) Gas turbine rating (b) Fog oil capacity (c) Fog oil capacity with unit designed .as smoke generator only (d) Maximum gas turbine, weight, dual purpose unit, i.e. both drawings disclose a 175 g.p.h.

350 g.p.h.

pump and smoke generator 165 lbs. (8) Fuel flow 10 g.p.h. (f) Type fuel used Diesel.

1000 hrs. expected.

Electric or hand starting.

Approx. $3,500 (500 units) (g) Gas turbine overhaul life (h) Type starting (i) Cost for dual purpose unit (1') Cost for single purpose smoke generator unit Approx. $1,500.

It is pointed out that the cost of converting a gasturbine driven boat, of the type described above, to smoke generating purposes is not more than $100, whereas present smoke generators used on landing craft cost approximately $1,800 each, thus the applicants invention results in a saving of approximately $1,700 per installation.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the invention herein chosen for the purposes of the disclosure, which do'not constitute departures from the spirit or scope of the invention.

What is claimed is: I

A smoke generator comprising a gas turbine, a gas turbine enclosing compartment, an eductor pipe attached to and extending through. a wall of said compartment and having one end thereof open to the interior of said compartment and the opposite end open to the surrounding atmosphere outside said compartment, an exhaust pipe connected to and extending from said turbine, said exhaust pipe being spaced from and concentrically mounted within said eductor pipe and terminating short of the atmospheric end of said eductor pipe, a first tubular nozzle within said exhaust pipe, said tubular nozzle having a constricted venturi type passage extending therethrough, an open ended pipe extending into the throat portion of said constricted passage and connected to a source of fog oil, the reduced pressure in said constricted passage serving as a means for drawing said fog oil into said nozzle, whereby said fog oil has vaporized in said exhaust pipe by exhaust gases from said turbine, thereby forming smoke; a second tubular nozzle located in, said exhaust pipe adjacent said first nozzle, said second tubular nozzle having a constricted venturi type passageway extending therethrough, an open ended tubular member extending into the throat portion of said constricted passage in said second tubular nozzle and connected to a supply of water, the reduced pressure in said venturi type passageway in said second nozzle serving as a means for drawing water into said passageway whereby water is injected into said exhaust pipe during vaporization of said fog oil, thereby cooling said exhaust pipe, and preventing coking of the fog oil.

References Cited in the file of this patent UNITED STATES PATENTS

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