US762178A - Means for heat jacketing and screening. - Google Patents

Description

No; 762,178. A PATBNTED JUNE 7, 1904,

W. A. MAGFADYEN.

MEANS FOR HEAT JAGKETING AND SCREENING.

APPLIOATION FILED OCT. 12, 1903.

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No. 762,178. PATENTED JUNE 7, 1904.

. W. A. MAGPADYEIf. MEANS FOR HEAT JAGKETING AND SCREENING.

APPLIOATION FILED 00T. 12, 1903.

N0 MODEL. 2 SHEETS-SHEET 2.

UNITED STATES Patented June 7, 1904.

PATENT OFFICE,

MEAN$ FOR HEAT JACKETING AND SCREENING.

SPECIFICATION forming part of Letters Patent No. 762,178, dated June '7, 1904.

Application filed October 12,1903.

To all whom it 77Ifl/Z/ concern:

Be it known that I, WILLIAM ALLISON MAO- FADYEN, advocate of the supreme court, a subject of the King of Great Britain, residing at Sunnyside, Pretoria, in the Colony of the Transvaal, have invented an Improved Means for Heat Jacketing and Screening, of which the following is a specification.

My invention relates to an improved means for heat jacketing and screening, and is intended to be used for intercepting and minimizing the transmission of heat from materials in a state of combustion and from solid bodies, liquids, or vapors which are at a higher temperature than their surroundings and also for preventing and minimizing the rise of temperature in ice and other congealed liquids or liquelied gases and in solid bodies, liquids, and vapors which are at a lower temperature than their surroundings. In order to effect this, I utilize the non-conducting properties of a vacuum combined with the I'efracting properties of certain. adiathermic vapors, chiefly aqueous vapor.

Throughout this specification I use the word jacket to indicate anything which keeps heat in any containing walls or vessels or tends to minimize the loss of heat or radiation I from or through such walls or vessels, and I use the word screen to indicate anything which keeps heat out of any containing walls or vessels or which tends to minimize or intercept the transmission of heat from the surroundings to contained substances, liquids, or vapors which It may be useful to keep at a .low temperature or to indicate anything which Serial N0. l'76,786. (No model.)

to intercept or minimize the transmission of heat by contact from particle to particle and also the transmission by convection-currents.

In dealing with the transmission of heat by, third, radiation, I use all or any of the wellknown means of intercepting or reflecting heat radiation, such as reflecting the rays, or

minimizing the radiation by using polished metallic surfaces, lining or coating with tinfoil, silvering, or using any of the substances which exercise a reflective power upon heatrays. I propose, however, to use in addition those gases and vapors, and in particular aqueous vap0rs,which have adiathermic properties imprisoned between walls which contain an air-vacuum, as a jacket or screen for heat radiation. I do not confine myself to aqueous vapor; but I prefer to use it for its greater cheapness in production and its general availability and efliciency. Aqueous vapor has the property of only transmitting through itself a small fraction of the radiant energy which itv receives and is thus peculiarly suited to check radiation, which passes unhindered through ordinary dry air or through a vac-.

uum. 1

I take an air-vacuum produced by any of the usual methods within containing-walls, fill it with aqueous vapor, and use the refractive agency thus produced as a radiation jacket or screen. The tension of the inclosed vapor varies with the temperature, and though.

the inherent refractive properties of the aqueous vapor are relied on for any temperature above that which will produce congclation of the vapor the amount of inclosed vapor may be varied according to the purpose for which the jacket or screen is designed or required, increasing the amount when high temperatures are intended to be dealt with. Useful results may also be obtained for a similar purpose by charging a chamber containing air with aqueous vapor. I reserve the right of using this arrangement either initially or for purposes of repair. However, where the utmost eflicieney is essential I prefer the airvacuum charged with aqueous vapor, as described.

In order, then, to prevent or minimize the transmission of heat by contact and conveyance on the one hand and by radiation on the other, I combine with the vacuum-jacket or screen, with its containing-walls, a jacket or screen consisting of an air-vacuum containing adiathermic gases or vapors, preferably aqueous vapor, with its containing-walls. The latter is placed, as a rule, on the side of and nearer to the source of heat. As convection-currents are set up in the vapor and a certain amount of heat is conveyed thereby to the farther wall, the vacuum, with its containing walls, is placed on the other or farther side away from the source of heat to intercept or minimize the communication of heat from such source. Thus in jacketing the vapor, with its contaming-walls, is on the inside, and the vacuum, with its containing-walls, is on the outside, while in screening the relative positions are reversed. This rule is, however, subject to exceptions, hereinafter indicated, where the addition of either element of the couple to some machine, manufacture, or contrivance already known, which substantially contains the other element already, is claimed to make the couple complete. Further, except where the jacket or screen is required or intended to be transparent at least one of the containing-walls should be of some substance opaque to the luminous rays of the spectrum, so as to intercept them and turn them into rays of dark radiation emanating from its own surface, which are more amenable to jacketing or screening by adiathcrmic substances, liquids, or gases. Where, however, the source of heat is intended to be used as a source of light, as in lamps and in incandescent bulbs for electric lighting, the opaque substance is not applied.

In all machines, manufactures, or contrivances where a chamber containing vapor which has adiathermic properties, such as aqueous vapor or steam, or a vacuum is already an essential part and is so disposed as to have the effect of a jacket or screen the other element of the couple may be simply added to produce the required results. Thus in applying this invention to jacket the incandescent electric bulb the adiathermic vapor, preferably invisible aqueous vapor, with its containing-walls, may be added, thereby forming substantially the same couple as has been indicated as necessary or desirable. Similarly, in applying this invention .to jacket a steam-jacketed cylinder the vacuum, with its containing-walls, may be simply added, thus forming substantially the same couple as has been indicated as necessary or desirable. In both cases, however, the complete couple, as already described, may be applied externally to the vacuum or the steam-jacket, if considered desirable for increased efficiency.

In cases where economy of space or elegance of form are important desiderata and it may be inconvenient to use the treble-walled chambers, which are required to contain the airvacuum, with the vapor and the vacuum, as described, I use the adiathermic vapor, preferably aqueous vapor, with its containing-walls, as a jacket or screen by itself. This applies more particularly to these uses or applications where from the nature of the case the containing-walls are formed of non-conducting or badly-conducting materials or substances, such as glass or earthenware, thus securing roughly the advantages proposed by the'use of the couple.

In carrying this invention into elfect with reference to any machine, manufacture, or contrivance I surround the same or such part of the same as is desired to be jacketed or screened with treble walled chambers or plates, one of which walls may be the surface or boundary of the said machine, manufacture, or contrivance. Where, as explained above, the adiathermic, preferably aqueous, vapor, with its containing-walls, is intended to be used singly, double-walled chambers or plates are used, one of which walls may be the surface or boundary of the said machine,manufacture, or contrivance. The form or shape of such walls or chambers is immaterial and may be designed difierently in every use or application of this invention to suit the various purposes of the said machines, manufactures, or

contrivances. The only indispensable condition is that each chamber should be capable of being hermetically sealed from the outer air and should have sufficient resisting power to enable it to withstand the pressure of the surrounding atmosphere or other external forces where they are felt. I/Vhere metallic substances are used as the material of the containing-walls, they should be united at the points of juncture as far as possible by nonconducting substances, such as glass or lead, so as to prevent as far as possible loss or transmission of heat by conduction to unjacketed or unscreened parts. Distance-pieces inserted between the walls or plates to enable them the better to withstand the pressure of the atmosphere should be of similar nonconducting material, and where treble walls are used the positions of the inner distancepieces should preferably not coincide with those of the outer distance-pieces. Though the precise form or shape of such walls or chambers is immaterial in designing, the general principle should be borne in mind that it is upon the characteristics and properties of the adiathermic, preferably aqueous, vapor polished.

and the vacuum and upon the efficiency of the same that reliance is placed and that it is the surface offered which is important, and the depth of the containingchamber is not important in comparison.

Wherever possiblethat is to say, wherever transparency is not a desideratum-the Walls or plates should be coated or lined with tinfoil, silvered or otherwise treated, so as to avoid and reflect radiation according to known principles, and metallic surfaces should be Further, in dealing with high temperatures and where the containing-walls are of metallic substances plates of glass may be inserted facing or covering the same, so as to increase the adiathermic effect. In the use of an adiathermic, preferably aqueous, vapor, with its containing-walls, as a jacket or screen for high temperatures an increasing amount of moisture may be supplied in the chamber for conversion into vapor as the temperature rises.

In applying or carrying out my invention I may use treble or double containing-walls of any suitable form hermetically sealed, so as to be impervious to ordinary air, and when necessary to resist atmospheric and other external forces containing suitable intermediate distance-pieces. In producing the vacuum and sealing off the chambers, with their containing-walls, Imake use of any of the wellknown suitable or eificient exhausting and sealing appliances.

In producing the required vacuum-spaces I do not limit myself to any particular method. To produce the vacuum, an ordinary air-pump may be used, and in order to secure the airvacuum containing aqueous vapor the space may be filled with steam at a tension which will drive out the air contained. The steam is then condensed by the application of vapor or liquid at a comparatively low temperature to the containing-walls. An air-vacuum containing aqueous vapor will then be produced and an amount of moisture left in the chamber.

The vacuum and air-vacuum may be sealed off in any well-known method. With materials capable of being melted in a blowpipeflame the flame may be applied to the tubes until the walls melt together. In dealing with boilers, furnaces, stoves, and the like, where the contained spaces may be large, small cocks may be inserted in the tubes near to the containing-walls. These are turned after the production of the vacuum, so as to prevent any communication with the outside air, and after the tubes have been removed the openings are closed with solder or other suitable substance, so as to inclose the cocks. A

In the accompanying drawings I illustrate various practical applications of my invention and a suitable device for producing by the Torricellian method the required vacuum whether complete or containing water-vapor. This method is preferable for many applications of vessel, together with the additional apparatus required for making the non-aqu eous vacuum. Figs. III and IV are respectively an elevation and across-section of a steam-cylinder, together with a double-chamber jacket for lagging the same according to my invention. Fig. V is a general view of a triple-walled nonconducting plate for constructional purposes, and Fig. VI shows a detail of the same. All the views are partly or entirely in section.

Figs. I and II illustrate a method and apparatus for producing the two sorts of vacuum in small articles made of glass. With slight alterations of details of construction and manipulation substantially similar methods and apparatus may be employed for producing worm in articles of any size or material.

Considering now the drawings in detail, in Fig. I a double-walled electric-lamp globe is shown ready for the production of a watervapor-bearing vacuum in its outer chamber 1, which, with the non-aqueous vacuum already existing in the inner bulb 2, completes the jacketing or screening system, as the case may be. Access to the chamber 1 is had through the tubes 3 4, which are passed into and made air-tight with the stuffing-boxes 5 6, the whole top part of the apparatus, including the funnel 7, the cock 8, and stuffing-box 6, being capable of a vertical movement on its supporting-standard 9 to facilitate the fixing. The standard 9 also supports the bulb by means of the ring 10. The whole system forms a continuous pipe or channel from the funnel through the cock 8, the chamber 1, the

the funnel, so as to displace the air in the whole system above the cook 12, the funnel acting as a reservoir to replace the bubbles as they rise with water. All air being removed, cock 8 is closed and 12 opened, whereupon the water in the system sinks until its surface is at a height above that of the tank-water determined by the atmospheric pressure at the moment; but in any case it will be a short distance ab ove the cock 11, which is then closed.

The space 1 is now devoid of air. but contains the required water-vapor, varying in amount according to the temperature of the water.

By the application of a bloWpipe-flame the tubes 3 and 4 are fused off and the openings sealed, so completing the bulb as far as the invention is concerned. By removal of the fused-off tubes from the stufiing-boxes the apparatus is made ready for the treatment of the next article.

Fig. II shows a double-jacketed glass bottle for containing substances to or from which transmission of heat is to be prevented. In this case, as the bottle is intended to retain the heat of its contents, the inner chamber 15 is first exhausted of air and filled with watervapor, as already described, and then inclosed in a third chamber fitted, like the second, with glass inlet and outlet tubes 16 and 17. The apparatus used is exactly that shown in Fig. I, with the exception that the air-tight globe 18 replaces the stand 19, Fig. I. The process also is similar up to and including the production of the vacuum; but before the chamber is sealed off the water-vapor is removed by condensation therefrom by applying any refrigerating agent or any cheap volatilizing liquid to the exterior of the globe. The effect is to cause the water-vapor to condense inside the globe, and the chamber being thus left almost entirely vacuous is sealed off with the blowpipe. Should the bottle be required to contain cold substances, the non -aqueous vacuum would be internal to the vapor-bearing vacuum for the reason set forth above.

Figs. III and IV exhibit a steam-engine cylinder lagged according to my invention. the former figure being an elevation, partly in section, and the latter a cross-section on the plane A B, Fig. 111. The lagging consists of a double-chambered annular glass jacket cast in halves and adapted to fit round projections on the cylinder, such as the steam-chest 20. My reasons for making the jacket of glass are, first, its low heat conductivity, and, secondly, that, as all three walls of the double chambers may be cast in one piece, the chain-- sealing off the chambers the two halves are placed in position round the cylinder and fastened together by bolts through the lugs 24: and to the cylinder-flanges by the screw-bolts 25.

Fig. V shows three corrugated iron plates 26 27 28, which, together with the side pieces 29 and the end plates 30, form a double-chambered heat-screen. 1n the drawings a large portion of plate 26, a corner of plate 27, and a part of the nearest end plate are represented as being broken off in order to more clearly show the construction of the whole. The end plates are made of lead on account of its low conductivity. For the same reason and for the sake of lightness the sides are of wood, shaped to the curves of the corrugated plates and faced on the outside with lead, as shown to an enlarged scale in Fig. VI, which is a vertical cross-section of the base of one chamber on the line C D, Fig. V. 31 is one of the distance-pieces used for stiffening the centers of the plates made of wood or other non-eonducting material.

Fig. VI also illustrates the device used for sealing the chambers without leaving projections which would prevent the close fitting of adjacent plates. Two of these sealing devices are fitted to each chamber at the top and bottom, respectively, as indicated at 32, Fig. V. A cup-shaped casting 33 is let into the wood 34, so that its under side is flush with the lead facing 35 thereof, to which it is soldered. The exhausting-pipe 36 makes connection with the chamber by screwing into a hole in the base of the cup. The sealing-valve is located inside the cup and consists of a mushroom head 37, from which projects the screwed stalk or shank 38, working through the base of the cup and terminating in a square, over which a spanner may be fitted. A rubber ring 39 is fixed to the under side of thehead and is stiffened by the metal ring 40,0f L section, attached thereto. The diameter of the mushroom head, the rubber ring, and the sti-lfening-ring is less than the bore of the cup by so much as is necessary to permit the free flow of water between them. I/Vhen the operation of exhausting the chamber is completed, the shank is turned by a spanner, thereby screwing down the head, which by compressing the rubber ring against the cup-base causes it to bulge laterally, and so seal the chamber- The exhausting-pipe is now detached and the projecting shank cut off flush, and to perfect the sealing a metal plate may be solderedover the hole from which the exhausting-pipe has been removed and solder run round the severed end of the shank.

I claim as my invention 1. A jacket or screen for heat comprising a means for intercepting the heat by interposing an air-vacuum containing vapor with adiathermic properties, and means for interposing a vacuum in connection therewith;

2. Means for jacketing or screening heat comprising the interposition of a sealed space containing vapor of adiathermic properties and a vacuum. I

3. Meansfor intercepting heat or cold comprising sealed inclosing walls provided with an intervening vacuum-space, and an aqueousvapor space.

4. Means for intercepting heat or cold comprising inclosing walls formed with superposed spaces, one of said spaces inclo'sing an air-vacuum containing vapor with adiathermic properties and the other space surrounding the vacuum.

5. A jacket or screen for intercepting heat or cold comprising a double wall having superposed spaces, one space inclosing a vacuum and the other space an air-vacuum containing vapor having adiathermic properties.

6. A jacket or screen for a machine, manufacture or' contrivance provided with a sealed coveringchamber containing vapor with adiathermic properties, and a sealed chamber containing a vacuum applied thereto, externally thereof.

7. Means for intercepting heat or cold made up of a ,plurality of substantially parallel walls, spacing means interposed between the walls at suitable points, the said walls' forming a vacuum-inclosing space and also inclosing a sealed space containing vapor having adiathermic properties.

8. Means for intercepting heat comprising a plurality of walls spaced apart, and sealed against atmosphere, to form chambers between them, one of said chambers containing means for intercepting radiant heat while the other chamber is capable of intercepting heat transmitted by convection.

9. Means for intercepting heat comprising double-spaced walls, means connecting one space between said walls with a steam-supply for charging said space with aqueous vapor, the other space between the walls inclosing a vacuum, and valve mechanism for controlling the introduction or exit of vapor or air from said chambers, and for sealing the latter.

10. Means for intercepting heat or cold comprising inclosing walls provided with a vacuum-space and a sealed aqueous-vapor space.

11. A jacket or screen for a machine or contrivance provided with a sealed coveringchamber containing vapor with adiathermic properties, and a chamber containing a vacuum applied thereto.

In witness whereof I have hereunto set my hand in presence of two witnesses.

-WILLIAJWI ALLISON MACFADYEN. Witnesses:

HAROLD ERNEST KIsoI-r, HENRY W'ILLIAM NOBLE LENNARD.

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