US2348668A - Tube type flash boiler water heating device - Google Patents

Description

J. R. WILSON TUBE TYPE FLASH BOILER WATER HEATING DEVICE Filed Oct. 4, 1941 2 Sheets-Sheet 1 7 r I INVENTOR 4 John RWi/Son May 9, 1944. J. R. WILSON TUBE TYPE FLASH BO-ILER WATER HEATING DEVICE Filed Oct. 4, 1941 2 Sheets-Sheet 2 D 0 Fa .O W E R n m J MM 64.4w,

Patented May 9, 1944 lUBE TYPE FLtASH BOILER WATER HEATING DEVICE John R. Wilson,

Penn Township,

Allegheny County, Pa., assignor, by mesne assignments. to Asbury G. Wilson, John Richard Wilson, and Theodore F. Wilson, Wilkinsburg, Pa., ccpartners trading as Hanlcn &- Wilson Company Application October 4, 194 1, Serial No. 413,593

6 Claims.

This invention relates generally to tube type flash boiler water heating devices and, although of general applicability, will be described herein particularly as applied to a heating device or steam boiler to be used in connection with aeroplane engines. In this application, the water tubes are so located that they are heated by the gases flowing through the exhaust manifold of the engine. a

Devices of the type contemplated by the present invention operate principally as flash boilers. By this it ismeant that when no steam is required to heat the cabin of the aircraft the boiler is dry and at the temperature of the manifold, which may be from 1000 F. to 1400 F. or more but that when steam is required for heating the cabin the system is opened and cold water rushes to the boiler, which, being red hot, causes the] water to flash into steam. This exerts extreme pressure and strains on the boiler. This cycle, that is running from red hot to the temperature of the incoming water, occurs many times during a flight, whereas if it were operating solely as a water heater, these extreme conditions would not exist.

In the accompanying drawings:

Fig. 1 is a plan view of the boiler or heating device;

Fig. 2 is a vertical front elevation of the device shown in Fig. 1;

Fig. 3 is a vertical transverse section taken on the line IIIIII of Fig. 2;

Fig. 4 is a vertical transverse section taken the line IV-IV of Fig. 2; 3

Fig. 5 is a vertical front elevation illustrating the construction of the water tubes and headers;

and r Fig. 6 is a longitudinal horizontal section taken on the line VI-VI of Fig. 2, illustrating a bailie secured to the forward Water tube.

Heretofore in tube type heaters provided with inlet and outlet headers for the water passing through the tubes, it has been the practice to locate the headers within the exhaust manifold through which the heated gases pass and to support the headers from the inside of the manifold shell by welding the headers directly to the inside or outside of the shell. This practice has led to considerable difficulties, because the extreme changes in temperature within the shell cause considerable expansion and contraction of the headers and the water tubes to which they are connected. This contraction and expansion has caused the welds to crack or the metal to pull apart from the welds.

In accordance with the present invention, I overcome or at least decreasei this tendency of the headers to pull apart from the welds to the shell by locating the headers outside of the shell, where they are not subjected to such extreme changes in temperature, and in addition I mount the headers on supports operatively secured to the outside of the shell, these supports having sufficient resiliency to prevent cracking or breaking away of the weld, due to contraction and expansion of the parts. The tubes extend through the shell and are connected td jthe headers which are mounted on the outside of the shell. Other features of the invention will become apparent from the following detailed description:

Referring more particularly tothe accompanying drawings, the exhaust manifold, which forms the shell in which the water tubes are located and through which the heated gases from the engine pass, is designated by the reference numeral 2. The heated gases from the engine flow through the manifold or shell in the direction indicated by the arrow in Fig. l, i. e., from left to right as viewed in this figure. A plurality of water tubes 3 extend vertically through the shell 2, four of such tubes being shown in the drawings, but it will be understood that any suitable number may be employed. Each of these tubes extends through openings in the top and bottom of the shell and is connected to a bottom header 4 and a top header 5. Water to be heated is supplied to the inlet header 4 through the connection 6 and after flowing through the tubes 3 passes into the header 5 and from the outlet header through an outlet pipe I, which is connected by a flanged coupling 8 to the outlet header. An important feature ofthe .present invention is the mounting of the headers 4 and 5. on the outside of the shell 2. Each of these headers is spaced from the outside of the shell a sufficient distance to enable air to flow past the headers, in order to cool them. Each of the headers is mounted on the outside of the shell 2 in a similar manner, so that a description of the mounting of the outlet header 5 will be sufiicient. This header is supported by a strap or plate 9, which passes over the top of the header and is welded thereto. The ends ll! of the strap are welded to a bafile support plate I I, which likewise is welded or otherwise secured to theoutside of the shell 2. The strap 9 or equivalent supporting means for the headers is preferably made of metal which is suiiiciently thin and of such character as to provide a somewhat resilient mounting for the header, in order that the header may move, due

" A and preferably at least about 1".

in Fig. 6, the side edges l3 of the baffle are se-.

cured to a ring 14 secured to the tube So. at a point about midway between the top and bottom of the tube, as shown in Fig. 3. The top l5 and bottom l6 of the baflle are welded or otherwise secured to the inturned flanged portions I! of the balile support plate I I. It will be noted that the baflie support plate I I is provided with the inturned flange portions H which extend inwardly of the manifold 2 adjacent the openings through which the water tubes extend.

The plates II which are located on the outside of the manifold {accordingly not only support the straps 9 which support the headers but they also support the baffle l2. This baflie spreads the heated gases flowing through the manifold so as to tend to equalize the distribution of heat to the different water tubes.

:It will be seen from the above description that the inlet and outlet headers for the water tubes are mountedoutside of the exhaust manifold or shell 2 through which the heated gas passes and that the headers are supported by resilient supports which allow for. expansion and contraction of the parts, due to, changes in temperature without causing the welds connecting the headers to the shell to crack or break.

A feature of the invention is that the diameter of the tubes 3 is made large enough to limit surging of the boiler. In the prior known boilers of the type contemplated by this invention, the 'inside diameterof the tubes is from about /4" to In such boilers, surging is a rather serious matter, the excessive surging being caused by the surface friction in the small diameter tubes. I make the tubes of an inside diameter which is sufficiently large so as to prevent excessive surging. The tubes shown in the drawings have an inside diameter of about 1%" but this may be varied considerably, depending upon the particular conditions of 7 use. In general, the inside diameter of the tubesshould be at least about Although some surging may occur even with the tubes of large diameter according t m invention, the diameter of the tubes is great enough to allow the water to return promptly to the boiler rather than be carried'through the steam lines to the radiator in the cabin. This reduces the strains onthe steam lines and radiator and after the first-flashing allows the boiler to operate as an ordinary steam boiler.

Although the invention has been particularly described as applied to an exhaust manifold of an' engine, the invention is not restricted thereto. The mounting of the headers outside of the shell through which the heated gas flows and the use of resilient supports mounted on the outside of the shell are useful, irrespective of whether the shell isconstituted by an exhaust manifold of an engine or is some other structure in which heated gases flow and in which water tubes may be located. I

While I have illustrated and described a preferred embodiment of the invention, it is to be understood that the invention may be otherwise embodied or practiced within the scope of the following claims.

Iclaim:

l. A tube type flash boiler water heating device, comprising a shell, means for passing heated gas through said shell, water tubes extending through said shell, a baffle inside said shell for preventing direct impingement of the heated gas on said tubes, bafile support plates secured to the outside of said shell and having openings through which said tubes extend, said bafile support plates provided with flanges adjacent the openings, which extend inside said shell, said baffie being connected to said flanges, and an inlet header and an outlet header mounted on the outside of said shell and connected to said tubes.

2. A tube type flash boiler water heating device, comprising a shell, means for passing heated gas through said ,shell, water tubes extending through said shell, a ballle inside said shell for preventing direct impingement of the heated gas on said tubes, balile support plates secured .to the outside of said shell and having openings through which said tubes extend, said bailie sup port plates provided with flanges adjacent the openings, which extend inside said shell, said bafile being connected to said flanges, an inlet header and an outlet header connected to said tubes and located outside of said shell, and header supports connected to said baille support plates. 3. A tube type flash boiler water heating device, comprising a metallic shell forming an-enclosure for the passage of heated gases, a plurality of tubes extending through said shell with their ends extending outside of the shell, aninlet header positioned exteriorly of said shell and connected to and communicating with one end of each of said tubes, an outlet header positioned exteriorly of said shell and connected to and communicating with the other end of each of said tubes, and a resilient strap-like member operatively connected to saidshell for supporting each header.

4. A tube type flash boiler water heating device, comprising a metallic shell forming an enclosure for the passage of heated gases, a plurality oftubes extending through said shell with their ends extending outside of the shell, an inlet header positioned exteriorly of said shell and connected to and communicating with one end of each of said tubes, an outlet header positioned exteriorly of said shell and connected to and communicating with the other end of eachof said tubes, and a resilient strap-like member extendmg around each header, the ends of said members being securely connected to the shell, whereby the headers are supported by the shell exteriorly thereof.

5. A tube type flash boiler water heating device, comprising -a metallic shell forming an-enclosure for the passage of heated gases, a plural ty of tubes extending through said shell with their ends extending outside of the shell, an inlet header positioned exteriorly of said shell and connected to and communicating with one end of each of said tubes, an outlet header positioned exteriorly or said shell; and connected to and communicating with the other end of each of said tubes, said headers being spaced from the the flow of air between 6. A tube type flash boiler water heating device, comprising a metallic shell forming an enclosure for the passage of heated gases, a plurality of tubes extending through said shell with their ends extending outside of the shell, each of said tubes having an inside diameter of at least /2", whereby excessive surging is prevented, an inlet header positioned exteriorly of said shell and connected to and communicating with one end of each of said tubes, 10

an outlet header positioned exteriorly of said shell and connected to and communicating with the other end of each of said tubes, and a resilient strap-like member for each header secured at its ends to the shell and formed intermediate its ends to extend around the adjacent header, whereby said headers are supported by the shell exteriorly thereof.

JOHN R. WILSON.

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