US2008528A - Boiler - Google Patents

Description

July 16, 1935. G, B WARREN 2,008,528

'BOILER Filed Sept. 3Q, 1955 Inventor-z Glenn B .War-ren,

His Attofneg.

Patented July 16, 1935 UNITED STATES BOILER Glenn B. Warren, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application September 30, 1933, Serial No. 691,689

3 Claims. (Cl. 122-250) The present invention relates to boilers for heating, evaporating and superheating a iluid such as water or mercury, more particularly to high pressure combustion boilers in which the fluid to be heated is forced through the heating elements and agpressure of several atmospheres is maintained in the combustion space. The circulation of fluid through the heating elements in this type of boiler is usually accomplished by the provision of pumps and the pressure in the combustion space may be obtained by a compressor for forcing air into the combustion space to maintain combustion therein, which compressor may be driven by a gas turbine receiving eX- haust gases from the boiler. The combustion gases are forced along the heating surfaces of the iluid containing elements at high velocity of the order of several hundred feet per second. This naturally results in a high heat transfer and makes it necessary to provide forced circulation for the lluid to be heated in order to avoid excessive heating of the fluid conducting elements.

The output of a boiler of this type is several times larger than that of an ordinary boiler with natural circulation and ilow of fluid and combustion gases respectively.

The object of my invention is to provide an improved boiler of the type specified which is simple in design and can be manufactured at low cost.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying I drawing.

In the single figure of the drawing I have shown a view partly in section of a boiler embodying my invention.

Broadly speaking, the boiler comprises two cylindrical double-walled bodies arranged in concentric spaced relation to define an annular space. Located in this annular space and connected between the two bodies is a helically wound tube defining a spiral or helical path. The inner body defines a combustion space which at one end receives combustible material, such as oil together with air for maintaining combustion and at theother end discharges combustion gases into the helical path whence the gases after having passed along the helical path are discharged into a stack or a gas turbine. Fluid to be evaporated and superheated is conducted to the inner body, then through the tube delining the helical path, when it flows through the outer body to be superheated and discharged. Each of the two bodies, as pointed out above, has an inner and an outer Wall. These walls may be formed in any desirable manner, such as by corrugated sheet metal or in a preferred construction by a tube or tubes.

Referring now more specifically to the rrangement illustrated in the drawing, the two bodies and the means for conducting fluid from one body into the other form a single tube receiving liquid at one end and discharging elastic iluid at the other.

The inner body has an inlet conduit IIJ for receiving fluid to be heated. The tube forming the body is helically wound with adjacent turns engaging each other. The engaging tube portions are united by fused metal vsuch as welds II or the like to render the space defined by the inner body gas-tight. The last turn I2 of the inner body is connected by a tube portion I3 to the inlet of a top layer of spirally wound tubes having an outlet I5 connected to a tube I6 helically wound about the inner body with adjacent turns spaced apart. The last turn I'I of the tube I6 is connected by a tube portion I8 to the first turn I9 of an outer cylindrical body. The turns of the outer cylindrical body engage each other and the engaging portions are united by welds 20 or other methods. The tube portion intermediate the outer and inner bodies are fastened either to the inner or the outer body. In the present instance they are secured to the inner body by welds 2 I. The last turn 22 of the outer body is connected to a second top layer of tubes 23 Which end in a conduit 24 for discharging superheated elastic fluid. The inner layer, as well as the outer top layer of tubes, are united by welds 25 and 26. A cap 2l is welded to the discharge conduit 24 and the outer top layer of tubes to prevent leakage of gases. The two top layers of tubes and the. cap 21 form in substance a cover or closing member for the outer cylindrical body.

The heating elements are in the present instance previded in a casing comprising a steel cylinder 28 concentrically spaced from the outer body. A top plate 29 is fastened to flanges 30 of the cylinder 28 by means of bolts 3|. The cylinder is supported on a base plate 32 having a central opening 33 for a burner 34. The outer body of tubes is supported by the. cylinder by means of brackets or an annular ring 35 Welded on one side to the cylinder and on the other side to the lower turns of the outer body. The inner body is supported on an annular partition 36 which is welded tothe base 32 and to the lower turn of the inner body. The burner 34 is centrally arranged within the space defined by the partition. An opening in the partition is connected to a conduit 31 for conducting compressed air into the combustion space. The lower end of the cylindrical steel body 28 has an opening connected to a conduit or stack 3'8 for discharging combustion gases.

During the operation the combustion gases formed in the combustion space of the inner bo'dy flow upward at high velocity and are forced through an annular opening dened between the last turn of the inner body and the inner top layer into the helical path dened between the inner and outer body. The velocity of the gases is considerably increased in said helical path. At the lower end of the helical path the combustion gases are discharged into the conduit or stack 38. Liquid forced through inlet Ill into the lower end of the inner body flows through the turns forming the inner body and under normal conditions is converted into vapor within the upper turns of the inner body. The conversion of liquid into vapor, however, may take place earlier or later depending upon operating conditions. From the upper turn of the inner body the fluid flows through connection I3 into the top layer I4, whence it flows through tube portion I5 into the tube I6 forming the helical path in which tube the liquid is normally superheated. From the end turn I1 of the last mentioned tube the fluid flows through connecting tube I8 into the lower turn of the outer body in which it is forced upward. From the last turn 22 of the outer body the iluid flows through the outer top layer 23 into the discharge conduit 24. Whereas I have shown the outer cylindrical body as being enclosed in a steel casing, such steel casing may be omitted if desired.

One advantage of my improved boiler lies in its simplicity. A standard size of this boiler may be constructed of standard tubes and any desirable output may be obtained by providing a plurality of such standard size boiler units. The output per unit volume combustion space is Very high and comparatively little floor space is accordingly needed for a boiler.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States:

1. In a single tube boiler, a helically wound tube with the walls of adjacent turns united by fused metal to dene a gas tight combustion space, means for conducting fuel and air at high pressure into the combustion space, a second tube with thc walls of adjacent turns united by fused metal in concentric spaced relation to the ilrst tube. a third tube connected between the rst and the second tube being helically wound into the space defined between the rst and second tubes in order to dcnc a helical path for receiving at one end gases from the combustion space, and a stack connected to the other end of the helical path, the combustion space having a large cross-section and being of a'volume suillcient to cause complete combustion of fuel therein, the helical path being of considerable length but small cross-section as compared with the crosssection of the combustion space to cause the combustion gases to flow at high velocity therethrough.

2. In a high pressure combustion boiler, the combination of an inner cylindrical body comprising a helically wound tube with adjacent turns thereof engaging each other and being united along their entire length by fused metal to form a gas-tight 4combustion chamber, means for conducting fuel and air at high pressure into said chamber, the combustion chamber having a large cross-section and a volume sufilcient to permit complete combustion of fuel therein, an outer cylindrical body concentrically arranged with the inner body, the two bodies forming an annular space having a width equal to the diameter of one of said tubes, the outer body comprising a helically wound tube with adjacent turns united by fused metal, and a tube for conducting fluid to be heated and evaporated from the inner body to the outer body, said last named tube being helically wound into the annular space between the two bodies to define a helical path for the gases discharged from the combustion space, the helical path having a small cross-section as compared with that of the combustion chamber to cause the combustion gases to flow through the helical path at high velocity.

3. In a boiler for heating and evaporating a fluid, two cylindrical bodies in concentric spaced relation, the inner body defining a combustion chamber, each body comprising a helically wound tube with adjacent turns of the tube engaging each other, a tube wound into the space intermediate the bodies to define a helical path communicating at the upper end with the combustion chamber, a portion of one of said tubes forming a ceiling for thev combustion chamber, means for conducting fuel and air into the lower end of the combustion chamber, the cross-section of the helical path being a fraction of that of the combustion chamber to cause a considerable increase l in velocity of the combustion gases discharged at the upper end from the combustion chamber into the helical path, and a conduit communicating with the lower end of the helical path for discharging combustion gases.

GLENN B. WARREN.

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