US2003579A - Heater - Google Patents

Description

June 4, 1935. J, H: CONANT 2,003,579

HEATER File d Aug. 15, 1952 iNVENTOR BY John ZLZorzamZ 22 ATTORNEY Patented June 4, 1935 UNITED STATES PATENT OFFICE HEATER Application August 15,

13 Claims.

This invention relates to devices for heating fluids such as water by means of gas, kerosene or other gaseous or liquid fuel. A common form of heater for such purposes comprises one or more coils of tubing helically disposed about a vertical axis. A burner is positioned beneath the lower turn of the coil'and the flame of the burner strikes the lower turn of the coiland heats the water therein and the hot gases pass upward giving more and more of their heat to the succeeding turns of the helical coil.

It has frequently been found that in such devices the coil near the bottom is rapidly eaten away, probably because of the combined effect of deposits such as lime inside the coil and of the heat and certain chemical action from the gases of the flame outside the coil. The time required for the corrosionto eat, through the walls and cause a leak varies under difierent conditions but two years is common, the time sometimes being longer and sometimesmuchshorter.

It is one of the objects of the present invention to increase the life of the heater coil so that the corrosive action of the flameor other corrosive action, either internal or external, will require a muchlonger period of time to eat through the coil suiflciently to cause it to leak. More specifically it is one of the objects of the invention to provide .a heater coil having thicker walls near the bottom thereof where the flame is hotter and where it strikes more directly on the coil. Still more specifically it is an object to provide the lower portion of the coil, such-as approximately one turn, in the form of a separate member to which is attached the lower end of the upper portion of the coil. 'It is also an object of the invention to make the upper portion of the coil of tubing such as copper and the lower member a non-ferrous casting such as brass; This casting preferably has a thicker wall on a portion of its under side where the flame strikes it directly than on the upper side where the flame does not strike it directly.

A further object of the invention is to protect the connection between the lower member or casting and the upper tubing from the direct action of the flame as by having a web between the flame and the connection.

A still further object of the invention is to provide a shelf-like portion or depression on the upper side of the member to catch condensation ,drippings. which if allowed to reach the burner are very objectionable.

. It is also an object of the invention to form the under surface of the memberso as to direct the 1932, Serial No. 628,850

gases from the flame toward the inner passage through the helix where their heating is more efiective.

- Another object of the invention is to provide a web or shield to protect the burner from down '5 drafts or back drafts which will sometimes blow out the flame. This shield is preferably incorporated in the member of thicker walls and the same physical structure is employed for serving both functions.

These and other objects of the invention will readily appear to those skilled in the art to which it appertains by a consideration of one embodiment thereof as set forth in the following description taken in connection with the accoml5 panying drawing in which Fig. l is a perspective view of a water heater in which is incorporated one form of the invention;

Fig. 2 is a vertical section of the heatershown 20. in Fi 1;

Fig. 3 is a plan View of the lower turn of the heating coil which turn is in the form of a separate member, a portion of the tubing entering the member being also shown;

Fig. 4 is a perspective view of the. member shown in Fig. 3 and also shows a portion of the tubing connected therewith;

Fig. 5 is an enlarged perspective view of a portion of the member shown in Figs. 3 and 4 and 30 shows more in detail the arrangement where the tubing enters the member and also the outer connection for the water supply;

Fig. 6 is a vertical section taken on the line 6-6 of Fig. 3; and

Fig. 7 is a vertical section taken on the line 11 of Fig. 3.

Referring to the drawing more'in detail the reference character I I indicates a compartment preferably in the form of a vertically disposed 40 cylinder in which is positioned a water coil indicated generally by the reference numeral I2. The water enters at l3 and passes upwardly as it is heated until it is finally discharged at M.

In the lower portion of the compartment H and 45 beneath the lower turn of the coil is positioned a burner l5 which in the drawing is shown as a vgas burner. The compartment H is preferably provided with a door [6 to permit ready access for lighting the burner and for other purposes. 50 Suitable openings I! are provided at the lower portion of the compartment l for the admission of air which is known as secondary air, there also being provision for the admission of primary air at the air mixer, not shown. There is a suitable discharge opening i8 at the upper portion of the compartment which opening, if desired, may be connected to a chimney.

The water coil 1 2 may comprise a single turn of tubing helically disposed about a vertical axis or there may be a plurality of such coils. In Fig. 2 there is shown two such coils one, indicated by the reference character is, formed with a smaller radius than the other, indicated by the reference character 22!, so that the inner coil is readily positioned within the outer coil. The lower portion of the coil or coils is in the form of a separate member 2 i. It is to be understood that while the member 21 is shown as constituting substantially one turn of the coil it may also be constructed as either more than one turn or less than one turn and is not to be considered as limited to one turn except as so limited in certain of the claims appended hereto.

This member 2! is constructed with walls 22 that are much thicker than the walls 23 of the tubing. There is provision made at 24 for the reception of the tubing which after insertion into the openings provided therefor are brazed in position. It will be noted that an interior passage 25 is provided through the member -2l which has a-much larger cross section than the tubing so that the water will flow therethrough more slowly and will heat more effectively as it is this first turn which is in direct contact with the flame from the burner. The member 21 is preferably a casting and is constructed of some suitable material such as brass. A projection 26 is provided on the member 2! and has an aperture 28 through which the incoming water passes. The projection 26 is preferably threaded as indicated at 29 for the convenient attachment of a water supply pipe, not shown. The water enters through the aperture 28, flows toward the right as indicated by the arrow A in Fig. 6 and after having made substantially one turn through-the helix of the member 2|, the water discharges from the member 2i into the tubing as indicated by the arrow B in Fig. 6. That portion of the member 2i which extends from the aperture 28 to the portion 24 is in the form of a web 34 and serves to protect the brazed connections between the coils l9 and 2E! and the member 2| from the direct action of the flame from the burner I5. It also helps to protect the burner against backdrafts.

It will be noted that the upper wall of the member 2| slopes downward from the outside as indicated at 3!! and also downward from the inside as indicated at 30 to provide a depression or trough to catch the drippings of water of condensation which without the provision as above described are apt to fall on the burnerand cause trouble, especially with oil burners.

The under side of the member 2| preferably slopes from the lowermost portion upwardly toward the inside as indicated at 32 and upwardly toward the outside as indicated at 33. It is desirable that the inwardly sloping portion 32 be greater than the outwardly sloping portion 33 so that the hot gases from theburner will be directed inwardly and will flow upwardly through the central passage of the coil where their heating is more eifective than the heating of' those gases which pass between the outside of the coil and the inside of the casing of the compartment ll. Because of the more effective heating there also results a better water circulation.

The member 2! being broader than the smaller tubing constituting the rest of the coil provides a barrier against down drafts or back drafts which sometimes blow out the flame of the burner.

It will be seen that much heavier Walls have been provided at the lower portion of the helix and whatever corrosive action takes place either external or internal will take more time to eat through the wall sufficiently to cause a leak. Furthermore it will be noted that the lowermost portion of the wall of the member 2! is somewhat thicker as indicated at 35 than the rest of the wall. The fact that the member 2! is formed separately and brazed to the tubing makes it possible .to remove and replace this portion of ie structure in'case of leak without scrapping the entire coil.

It is to be understood that the foregoing embodiment of the invention has been described for purposes of illustration only and various changes may be made in the structure set forth without departing from the spirit and scope of the invention as defined in the subjoined claims.

I claim:

1. In a water heater, a water coil of thinwalled tubing, an annular member of relatively thick walls to which said tubing is connected positioned beneath said coil with its opening in alinement with the opening through said coil, a burner positioned so that the flame therefrom strikes directly on said member, and means associated with said member for preventing the flame from striking the connection between said tubing and said member. 2. In a water heater, a water coil of thin-walled tubing, a member of relatively thick walls of approximately the same form as'one turn of said coil positioned below and connected to said tubing, and a burner positioned beneath said member so that the flame therefrom strikes directly on said member, said member having a web-like portion positioned beneath the connection between said tubing and said member to protect said connection from the direct action of the flame of the burner.

3. A water heater comprising a plurality of water coils of thin-walled tubing helically disposed about a vertical axis, a thick-walled casting positioned at the bottom of said coils and having a helical Water passage of approximately a singleturn therethrough, said casting having a plurality of openings for the reception of the ends of said coils in which position the coils are brazed in place, a burner positioned beneath said casting, said casting having a web-like portion adapted to shield said brazed connections from the direct action of the flame of the burner.

4. In combination, a water coil helically disposed about a vertical axis, and an annular member positioned at the bottom of said coil and connected therewith and. having a water passage of approximately one turn therethrough, a section taken through one side of said member having a maximum Width at the top thereof and having its upper wall sloping downward from both sides toward the middle to provide a depression.

In a water heater, a water coil helically disposed about a vertical axis, an annular member positioned at the bottom of said coil and having a water passage of approximately one turn in length therethrough, and an annular burner positioned beneath said member, the lower surface of said member sloping upwardly and radially toward both edges thereof, the portion sloping inwardly being greater than the portion sloping outwardly to direct the greater portion of the hot gases toward the center.

6. In a water heater, a water coil helically disposed about a vertical axis, an annular member positioned beneath the lower turn of said coil and connected thereto and having a water passage of approximately one turn therethrough, and a burner positioned beneath said member.

'7. In a water heater, a Water coil helically disposed about a vertical axis, an annular member positioned beneath the lower turn of said coil and connected thereto and having a water passage of approximately one turn therethrough, and a burner positioned beneath said member, the thickness of the walls of said member being greater than the thickness of the walls of said coil.

8. In a water heater, a water coil helically disposed about a vertical axis, an annular member positioned beneath the lower turn of said coil and connected thereto and having a water passage of approximately one turn therethrough, and a burner positioned beneath said member, a portion of the wall of the under side of said memher having a greater thickness than the wall of the upper side. i

9. In a water heater, a water coil helically disposed about a vertical axis, an annular member positioned beneath the lower turn of said coil and connected thereto and having a water passage of approximately one turn therethrough, and a burner positioned beneath said member, the thickness of the walls of said member being greater than the thickness of the walls of said coil and the walls of said member also being thicker on the under side of said member than on the upper side of said member.

10. In a water heater, a water coil helically disposed about a vertical axis, and a burner positioned beneath the lower turn of said coil, ap-

proximately one turn at the lower portion of said coil having a greater water capacity than the capacity of one turn at the upper portion of said coil, said turn also being constructed to have greater wearing qualities against corrosion.

11. In a water heater, a water coil helically disposed about a vertical axis, an inlet at the lower end of said coil, an outlet at the upper end of said coil, approximately one turn at the lower end of said coil having a greater internal cross sectional area than the turns of the rest of the coil, said turn also being constructed to have greater wearing qualities against corrosion, and a burner positioned beneath said larger turn so that the flame therefrom is in direct contact with said turn.

12. In a water heater, a water coil of thinwalled tubing helically disposed about a vertical axis, an annular burner positioned beneath said coil, a member of a material having greater resistance to corrosion than said tubing of annular form positioned between said coil and said burner with substantially one turn of water passage therethrough of greater cross-sectional area than said tubing, said member having thicker walls than said tubing and with its lower wall thicker than its upper wall.

13. In a water heater, a water coil helically disposed about a vertical axis, the upper portion of said coil being of relatively thin-walled tubing, and approximately one turn at the lower portion of said coil being a separate member of different material having a greater resistance to corrosion than said tubing, the Walls of said member being homogeneous and of greater thickness than said tubing.

JOHN H. CONANT.

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