US2155383A

US2155383A - Method and apparatus for transferring heat

Info

Publication number: US2155383A
Application number: US52506A
Authority: US
Inventors: Richard H Carr
Original assignee: Pure Oil Co
Current assignee: Pure Oil Co
Priority date: 1935-12-02
Filing date: 1935-12-02
Publication date: 1939-04-25
Anticipated expiration: 1956-04-25

Description

April 25, 1939. R H, CARR 2,155,383

METHOD AND APPARATUS FOR TRANSFERRING HEAT Filed Dec. 2, 1955 INVENTOR Rz'cAavdH Carr N- M ATTORNEY Patented Apr. 25, 193

Richard H. Carr, Evanston, 111., Pure Git Company, Chicago, m, a ration of Ohio Application December 2, 1935, No. 52,506

16 Claims.

This invention relates to improvements in method and apparatus for heat transfer, and more particularly to improvements in the construction of internal combustion engine pistons and the method of dissipating heat from the heads of such pistons.

It is well known that the high temperatures attained in internal combustion engines cause excess heating of the piston heads with resultant formation and deposition of carbon on the head and piston rings. Carbon accumulations interfere with the proper operation of the engine, necessitating frequent cleaning with attendant expense and loss of time.

One object of my invention is to provide novel means for transferring heat from one portion to another portion of an enclosed hollow body.

Another object of my invention is to provide a method of rapidly dissipating heat from the head end of a piston, by transferring it to the skirt and rear end thereof, from which it is absorbed by a surrounding water jacket or carried off by other cooling media such as air.

A further object of my invention is to provide pistons capable of operation in an internal combustion engine without becoming excessively heated adjacent the head end.

I accomplish the foregoing and other objects of my invention by partially filling an enclosed hollow piston or other body witha fine metallic or other dust having good heat conductive properties. The dust should be of such degree of fineness that upon shaking or reciprocating a body containing a gaseous medium and dust, the latter will remain suspended as a fog in the gaseous medium for an appreciable length of time. The rapid reciprocation of a piston in an internal combustion engine produces violent shaking of the dust, thereby causing it to become suspended in the gas. Asa result, a continuous heat transference medium is produced in the form of the dust laden gas.

As a gaseous suspension medium an inert gas such as carbon monoxide, carbon dioxide, nitrogen, etc., is preferable in order to protect the metallic or other dust from oxidation or deterioration.

The quantity of dust enclosed in the piston will vary with the size of the piston, but in any case is insufiicient to completely fill the piston but is "preferably in excess of the amount necessary to saturate the gas or remain suspended therein when the piston is reciprocated during normal operation of the engine. Thequantity of dust should not fill the internal space of the piston but should be capable of being freely shaken about. In order to more clearly comprehend the nature of my invention, the following detailed description should be referred to in connection with the accompanying drawing of which as great as possible.

The single figure is a diagrammatic illustration of one form of piston embodying my invention.

Referring to the drawing, the numeral i indicates generally a piston having head 3 and shirt 5. The piston shown in the drawing represents a conventional type of piston used in stationary gas engines. A connecting rod i is riveted to the head end of the piston. A plate 9 is welded to the rear end of the piston. The rod '8 a through a hole in the middle of the plate t and a stumng box ll prevents leakage around the connecting rod. The plate has a second opening which is adapted to be closed by a screw plug it. The hollow interior of the piston is partially filled with metallic or other finely divided powder it, placed therein by removing the screw plug l3. The hollow interior of'the piston is also preferably filled with an inert gas such as nitrogen or carbon dioxide, although air may be used. The gas may or may not be placed under pressure. The amount of powder placed in the interior of the piston may be slightly in excess of the amount that the gas can hold in suspension in order to insure that the density of the dust laden gas is Although a lesser amount of dust than that necessary to completely saturate the gas, may be placed in the piston, it is prefer-.

able to have as dense a fog as possible. As metallic dust, steel, aluminum or copper dust of the fineness of that used in the preparation of paints, is suitable.

Although I have described my invention in connection with pistons to be used in connection with stationary gas engines, the invention is also applicable to automotive internal combustion engines which necessitate the use of a moveable connecting rod. In such cases, instead of connecting the rod to the head end of the piston, the rod may be connected to the skirt of the piston at the rear end thereof by means of a wrist pin.

Instead of welding the plate 9 to the rear end of the piston, the piston may be cast with the rear end plate as an integral part thereof. In such cases an opening in the rear plate will be provided for removing the core, used in preparing the casting, and to provide a means for filling the interior of the piston with gas and dust.

When the piston is placed in operation, the rapid reciprocation thereof will cause the dust to become suspended in the gaseous means in the manner illustrated in the drawing. The suspension of the dust creates a heavy dense fog which acts as a continuous conducting medium from 1 the head to the skirt and rear end of the piston.

thereby rapidly dissipating the heat from the head end to the surrounding cooling medium which may be either in the form of a water jacket or other cooling means.

One of the advantages of employing finely divided dust as a conducting mediumis there is no likelihood oi the conducting medium pounding against the rear and head end of the cylinder during reciprocation as would be the case if large particles were contained therein and shaken back and forth. Since the dust is composed of a material that has a melting point in excess of the temperatures attained by the piston, it remains in a solid state during operation. In addition to acting as a continuous heat transference medium, the dust fog has a tendency to concentrate at opposite ends of the piston during the backward and forward stroke thereof, thereby providing a more effective means of taking up the heat from the head end and carrying it to the rear end.

As an illustration of my invention and without intending to be limited to the specific figures given, a piston weighing four hundred pounds and having an internal volume of two thousand six hundred cubic inches, was fllled'with nitrogen under atmospheric pressure and seven pounds oi copper dust approaching colloidal dimensions were placed therein. The piston when operated in a. stationary gas engine proved entirely satisi'agziry in preventing over-heating of the piston By means 01' my invention, over-heatingoi the head of the piston can be avoided, and the formation and deposition of carbon and sticking of piston rings to a large extent eliminated. The

weight of the piston is not materially increased since the amount of dust is comparatively small in comparison to the weight of the piston. Moreover, improved lubrication of the cylinder and piston is obtained. The reduced carbon formation also permits operation at higher compression ratios.

It will be understood that although I have described my invention in connection with its use in pistons in internal combustion engines, the invention in its broad aspect is applicable to transfer of heat in any body where it is desired to rapidly dissipate heat from a hotter to a cooler portion of the body.

What I claim is:

1. The method of transferring heat from one portion to another portion of a closed hollow body which comprises filling the body with a gaseous medium, partially filling the body with a dust of relative high heat conductivity, said dust being sufliciently fine to remain suspended as a fog in said gaseous medium upon shaking said body, closing said body and shaking said body whereby to produce a continuous heat conducting medium comprising dust laden gas by means of which heat passes from a hotter to a cooler portion oi said body.

2. The method in accordance with claim 1 in. which the metallic dust is selected from the group consisting of copper, aluminum, iron, and alloys thereof.

3. The method in accordance with claim 1 in which the gaseous medium is substantially inert toward the dust under the conditions to which the dust is subjected.

4. The method in accordance with claim '1 in.

which the gaseous medium'is selected from the group consisting of nitrogen, carbon monoxide, carbon dioxide, hydrocarbon gases and mixtures thereon Y 5. The method of distinct* heat from the head end of aclosed hollcwpiston cl operasuspended in the gas.

tion of an internal combustion engine which comprises filling the hollow space of the piston with.

a gaseous medium, and partially filling the hollow space with a heat conducting dust of sumcient fineness to remain in suspension as a fog in said gaseous medium during reciprocation of said piston, closing the piston and reciprocating the piston at a rate sufllcient to cause the dust to become suspended as a fog in. the gaseous medium.

6. Method according to claim 5 in which the dust remains solid under operating conditions;

7. Method according to. claim 5 in which the dust is a metallic substance which remains solid 10. Means according to claim 9 in which the gaseous medium is inert toward the dust and the dust is a metallic substance which does not melt at the temperatures to which it is subjected.

11. A piston comprising an enclosed hollow space, said space extending to the head end of said piston, a heat conductive dust in said space, a gaseous medium in said space, said dust being present in insufficient quantities to fill said space and being of sufilcient fineness to become suspended as a fog in said gaseous medium during reciprocation of said piston.

12. A piston in accordance with claim 11 in; which the dust is a metallic powder which remains solid at temperatures to which said piston is subjected during operation.

13; A piston in accordance with claim 11 in which the gaseous medium is inert toward the dust at temperatures to which the dust is subiected.

14. A piston comprising a completely enclosed hollow space extending to the head of said piston, high melting point metallic dust enclosed in said space, a gaseous medium, inert toward said dust, in said space, said dust being of suflicient fineness to remain suspended as a fog in said gaseous medium during reciprocation of said piston and being present in insuflicient quantities to fill said space. i

15. The method of transferring heat from a hotter portion to a cooler portion of a closed hollow body containing metallic dust and gas which comprises shaking the body containing gas and heat conducting metallic dust, suiliciently violently to cause the dust to become suspended and remain suspended as a fog in the gas.

16. The method of transierring heat from'the head end to the side walls and rear end of a hollow enclosed piston containing gas and heatconducting metallic dust, which comprises reciprocating the piston at a speed suiliciently great to cause said metallic dust to become and remain MARI) H. CARR.