US2825399A

US2825399A - Vaporizing pot type burner

Info

Publication number: US2825399A
Application number: US459792A
Authority: US
Inventors: Herbert M Reeves; James E North; Earl D Hillebrand
Original assignee: Heil Quaker Corp
Current assignee: Heil Quaker Corp
Priority date: 1954-10-01
Filing date: 1954-10-01
Publication date: 1958-03-04
Anticipated expiration: 1975-03-04

Description

March 4, 1958 H. M. RE-EVES ETAL 2,825,399

VAPORIZING POT TYPE BURNER Filed 001?. l, 1954 31 22am 257:5 $4EBBEBT PL BEEvEs JAMEs E. NOBTH EARL D. H/LLEBBAND rates 2,825,399 VATORIZING PST TYPE BURNER Application October 1, 1954, Serial No. 459,792 2 Claims. (Cl. 158-91) The present invention relates in generalto liquid fuel burners and, more particularly, to vaporizing pot type burners which find use, for example, in oil burning stoves and furnaces.

The general aim of the invention is to make possible improved and smoothly variable control of the rate of fuel combustion in pot type burners, giving infinitely fine adjustment between the limits of a pilot flame and the maximum high fire flame for which the burner is designed.

Further to that aim, it is an object of the invention to provide an improved pot type burner wherein the exposed surface area of liquid fuel is automatically varied with the rate of fuel feed, the rate of vaporization and combustion thus being smoothly controllable.

Another object of the invention is to provide an improved burner in which time lag in the response of flame height to changes in fuel feed rate is drastically reduced.

Still another object is to provide such a burner in which runaway action does not take place, the liquid fuel being partially shielded from the heat of a high flame. Radiated heat from the flame aids in producing the vaporization necessary for the maximum flame, but unduly great vaporization is prevented.

A further object is to provide such a burner which is of simple and economical construction, reliable in operation, and readiiy dismantled for cleaning purposes.

Other objects and advantages of the invention will become apparent as the following description proceeds, taken in conjunction with the following drawings, in

which:

Figure l is a vertical section of a pot type burner embodying the features of the invention;

Fig. 2 is a bottom plan View of the pilot housing empioycd in the burner of Figure l; and V Fig. 3 is a detailed view in section showing the manner in which the burner pot is supported.

While the invention has been shown and is described in some detail with reference to a particular embodiment thereof, there is no intention that it thus be limited to such detail. On the contrary, it is intended here to cover all modifications, equivalents, and alternative constructions falling within the spirit and scope of the invention as defined by the appended claims.

Referring now to the drawing, a pot type burner it) here illustrated as an exemplary embodiment of the invention, comprises generally a pot 11 which, in this instance, is substantially in the shape of a cylinder. The pot is formed of very similar upper and lower sheet metal halves 11a, 11b which may be formed to their approximate shapes by the same dies on a metal press, and then finished to their individual configurations. A simple interlocking seam at 12 tightly fixes the two halves together. For supplying primary air to the upper portion of the pot, its side Walls are made perforate, that is, formed with a plurality of holes 14 arranged in vertically spaced rows. Primary air is supplied to the bottom portion of the pot through a plurality of holes 15 formed at a downwardly directed angle in an inturned bead 16. The air entering those holes naturally flows downwardly to strike the surfaces of liquid fuel present in the bottom of the pot, thus readily causing the necessary vaporization.

The upper end of the pct 11 is formed with a large central outlet opening 13 and means are provided for mounting the entire pot in a manner such that the opening 18 is alined with a matching opening 19 in a supporting partition 20. The partition'20 and the top of the pot 11 are shaped and interrelated to define a passage through which secondary air is supplied to and mixed with fuel vapor rising from the interior of the pot in a manner to promote efficient combustion of the fuel. As here shown, the pot 11 is suspended from the apertured partition 20 which, in turn, is fixed, as by welding at its periphery, in a casing 21 defining the main combustion chamber at 22. Self-tapping screws 24, inserted through the partition 20 at points spaced around the opening 19, are engaged with matching holes 25 in the top of the pot. The pot 11 and the partition 20 are curved to define an upwardly and inwardly tapering passage 26 terminating in an annular port 28 just above the opening 18. In this manner, secondary air is drawn up through the annular space between the side walls of the pot 11 and the casing 21, the velocity of such air being increased in the tapering passage 26 so that the air is thrown horizontally into the rising vapors and mixes thoroughly with the latter. Accurate spacing of the pct 11 and partition 20, and thus accurate determination of the area of the port 28 is achieved by the provision of a series of downturned tabs 29 formed in the partition. The screws 24 are merely tightened until the top of the pot is drawn firmly against the tabs 29, the dimension of the port 23 thus being accurately determined each time that the parts are assembled.

In liquid fuel burners of the general type described, the problem of controlling flame height and resultant heat presents real difliculty. Once vaporization and burning of liquid fuel in the bottom of the pot is initiated, the heat supplied by the small flame produces progressively greater vaporization and burning so that without some special provision, a runaway action occurs. While various attempts have been made in the past to solve these difficulties and while some prior proposals have resulted in burners which would successfully hold a small pilot flame, none is known which permits perfectly smooth adjustment of the flame level between a pilot flame and the maximum heat for which the burner is designed.

In accordance with the invention, the difficulty is solved by so forming the bottom of the pot 11 that the exposed surfaces of liquid fuel supplied thereto varies smoothly and proportionally in area with the amount of the fuel present. In addition, means are provided such that a part of the exposed surface of liquid fuel is subject to direct radiation and heating from a flame in the upper part of the pot only when there is a relatively great amount of fuel present and a high flame is desired.

In the present instance this is accomplished by crowning the bottom 30 of the pot l1 upwardly at its central portion 30a. That is, the pot bottom is formed in a generally upwardly concave shape so that a small amount of fuel present in the pot bottom lies in an annular ring and as more fuel is added, it progresses inwardly toward the pot center, thus exposing a proportionally greater surface area from which vaporization may take place. It will be noted that in order to obtain the maximum advantage of the invention, the pot bottom should smoothly rise from its lowest level at the periphery to its highest level at the central portion so that the exposed surface area of liquid fuel is a direct function of the amount of fuel present.

ass-5,399

puddle beneath said ring, and at higher feed rates lies in References Cited in the file of this patent a puddle of greater area extending into said housing, T D TAT P T whereby at such higher feed rates said ring shields a por- UNI E S ES A ENTS tion of the fuel in the pot bottom from high flames in 2,369,999 Behrendt et 1945 th ti f th t t I. v m u dul ta 2,466,563 Stempel et a1. Apr. 5, 1949 j ggfi gf fif f F e e n y 5 2,535,923 Hill Dec. 26, 1950