US2641205A - Cooling wall for heated chambers - Google Patents

Description

June 9, 1953 R. DOLE Z AL. 2,641,205

COOLING WALL FOR HEATED CHAMBERS Filed Oct. 23, 1947 FIC12 IN V EN TOR.

Patented June 9, 1953 UNITED STATES PATENT OFFICE Application October 23, 1947, Serial No. 781,648 In Czechoslovakia June 19, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires June 19, 1965 4 Claims. 1

The invention relates to cooling walls for heated chambers, and relates more particularly, to cooling walls having ducts.

The ducts are arranged in the chamber wall in parallel side-by-side relationship. A cooling fluid and. particularly a gaseous cooling fluid, such as air, is passed through these ducts. The cross section of the ducts differs; the duct nearest to the heated chamber has the largest cross section and this cross section is gradually reduced in the direction from the chamber towards the outside atmosphere.

The total cross sectional area of the wall or its sections respectively is smaller than the total cross sectional area of the ducts.

The walls consist in conformity with this invention preferably of individual adjacent sections, each containing one series of cooling ducts.

The cooling wall forming the subject matter of this invention is illustrated by way of example in the accompanying drawings, in which Fig. 1 is a fragmentary sectional view of a wall in accordance with the invention; and

Fig. 2 is a sectional view taken on line 2--2 of Fig. 1.

There are'provided three and generally any greater number of cavities marked with the letters C, E, G.

In a space designated A, before the wall, a

flame or some other medium of high temperature prevails,-which conveys its heat to the wall B by contact and mainly by radiation. The heat conveyed to the wall B passes by contact into the cooling gas, for instance air, flowing in the cavity C, and is radiated besides to the cooler wall D, the absorption of the radiated heat by the gas in the cavity C being in view of its smaller thickness.- Again the heat is withdrawn on the one hand from the wall D by contact with the cooling gas flowing in the cavities C, E, and on the other hand is conveyed by radiation to the wall F. From this the heat flows into the cooling gas in the cavities E and C, and by radiation to the wall H.

The heat dissipation could be continued if more cavities than three are available. The residual heat which reaches the wall H passes through this wall and the insulating layer I.

It is apparent from the drawing that in order to maintain the flow of heat due to radiation from one wall to another, the wall B must be the Warmest, the wall D cooler than the wall B and so forth, so that the last wall H will have the lowest temperature measuring but a few degrees above the temperature of the cooling gas.

This naturally requires the depths of the cavities C, E, G to be different if an equal warming of all the flows of the gas in all the variously located cavities of the element is to be maintained, and thus the most favorable cooling effect to be attained. Owing to the gradually decreasing temperature of the walls B, D, F and H the thermic difference between the wall and the cooling gas will also decrease. The cavity C may, therefore, be the hottest and have the most powerful flow; the rest of the cavities must be shallower by degrees.

The advantages of the construction described above are the following:

As has been pointed out, the conveyance of heat in accordance with the invention takes place by radiation from the wall B to the walls D, F and H and thence by contact to the flows of the cooling gas in the cavities C, E and G. This has the same effect as if, with a gas-cooled wall of elements having only one cavity each, either (a) The velocity of the gas flow in the cavity C were considerably increased, thus increasing the passage of heat from the walls B and D into the cooling gas, or

(b) The surface of the heat-exchanging area of the walls B and D were considerably enlarged on the side of the gas in the cavity C, or

(c) The difference between the temperatures of the flame in the room A and that of the gas in the cavity C were considerably increased by using gas considerably cooler, or (d) The cooling gas in the cavity C were replaced by a medium absorbing the thermal radiation more intensely.

By this increase of the heat transfer from the side of the cooling gas the total amount of heat passing through the wall B will be increased. The coefficients of heat transfer from the side of the medium (for instance, the flame) in the room A remaining the same, the increase of the difference between the temperature of the medium in the room A and that of the surface of the wall B is necessarily involved. For example,

(1) The temperature of the external wall B which is exposed to the action of the hot medium in the room A will be considerably decreased in comparison with an uncooled wall or a cooled wall provided with only a single cavity, which involves a considerable prolongation of the life of the wall;

(2) A large transfer of heat through the wall B will facilitate a high warming of the cooling gas in the cavities, since with a highly conductive material and a small thickness of the walls d: B, D and F the amount of the heat which has passed through the wall B can be considerably increased with a sufiicient number of cavities in the element if compared with a wall consisting of an element with only a single cavity;

(3) Owing to the temperature of the last wall I-I beforethe insulating layer I being but a few degrees above the temperature of the cooling gas, the flow of heat forming the bulk of the loss of heat by conduction to the surroundings is of no practical importance.

It will be apparent to those skilled in the art that the novel principles of the invention disclosed herein in connection with specific .exemplifications thereof will suggest various other :modifi cations and applications of the same. It is accordingly desired that in construingvthe breadth of the appended claims they shall not be limited to the specific exemplifications of the invention described herein.

Having thus described .the invention, what I claimas newanddesire to be secured by Letters Patent, isas follows:

1. A cooling wall structure "for combustion chambers comprising a first inner wall element which directly encloses the combustion chamber, a second wall element locatedin parallel'outwardly spaced relationship with said first wall element, a first setof partition walls disposed between the said two wall elements in parallel relationshipltherewith and spaced from the inner and outer wall elements and from each other a successively decreasing distance from the inner Wall element to the outer wall element, a pluralitynof secondary parallel .and aligned ,parti- :1:

tion wallsaconnecting said wall elements and the firstmentioned partition wall members at spaced intervals throughouttheir extent whereby a plurality of separate seriesbf flues result, the respective fiues of each series being of. successively decreasing -.cross sectional area from the inner wall element to the outer. .wall element and means for passing .-a cooling gas through said fiues.

2. A cooling wall structure for combustion chambers comprising arfirst inner wall element which directly encloses .the combustion chamber, a second wall element located in parallel outwardly spacedcrelationship with said first wall element; a first setof partition walls disposedlbetweenthe said two wallelementsiin parallel relationship therewith and spaced from the inner and outer wall elements and from each other a successively decreasing .distance from the inner wall element to the outer wall element, a ,plu-

4 rality of secondary parallel and aligned partltion walls connecting said wall elements and the first mentioned partition wall members at spaced intervals through their extent whereby a plurality of separate series of flues result, the respective flues of each series being of successively decreasing cross-sectional area from: the inner wall element to the outer wall element, means for passing a cooling gas through said flues and a heat insulating wall disposed at the outer face ofsaid-second'wall element adjacent to the outside atmosphere.

3. A cooling wall structure for combustion chambers comprising a first inner wall element whichdirectly encloses the combustion chamber, a second wall element located in parallel outwardly spacedrelationship with said first wall element, a first set of partition walls disposed between the said two wall elements in parallel relationship therewith and spaced from the inner and the outer wall elements. and from each other a successively decreasing distance from 'the innerwall element to the outer wallelement, 'a plurality of seoondary'parall'el and "aligned partition walls connecting said wall elements and the first 'mentioned'p'artition wall members at spaced intervals throughouttheir extent whereby a plurality of separate seriesof fiues result, the respective flues or each series being of sue cessively decreasing cross-sectional area from the inner wall elementto theouterwall'element means for passinga cooling 'gasthroug'h said hues and a heat insulating'wall disposed at the outer face of said second "wall element adjacent to the outside atmosphere, the saidinsulating wall having at least twice'thethickness 'of 'the said second wall element.

4, A cooling wall structure according to claim 1, wherein the wallelements and the first setof partition walls have an 'equal'thickne'ss.

RICHARD DOLEZAL.

ReferencesCited in the 'file'of this patent UNITED "STATES PATENTS Number Name Date Re.17,13'7 :Eisenmann Nov. '20, 1928 539,730 Falding -May 21, '.1805 1,622,431 Feigenbaum Max: 29, 1927 1,674,422 Allen June 19, 1928 1,688,321 Abbott Oct- 23.1928 1,701,287 Waite Feb. -5, 1929 FOREIGNPATENTS Number Country Date 15,231. Netherlands Sept. .15, "1925

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