US2051215A - Heater structure - Google Patents

Description

INVENTOR r Aug. 18 1936. c. D. JONES HEATER STRUCTURE Filed May 15, 1935 Patented Aug. 18, 1936 PATENT, OFFICE I HEATER s'moorunn Chester D. Jones, Pittsburgh, Pa., assignor to Pittsburgh Water Heater Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application May 13, 1935, Serial No. 21,121

7 Claims.

This invention relates broadly to heater structures, and more particularly to a structure for use in heaters for transferring heat from a heat source to a fluid contained in a conduit, such, for example, as a coil. In certain of its more specific aspects the invention relates to a structure es pecially well adapted for use in water heaters, and more particularly instantaneous water heaters. Purely for purposes of explanation and illustration the invention will be described as embodied in an instantaneous water heater.

In instantaneous water heaters it is necessary to transfer heat rapidly from a heat source, such as a burner, to a conduit, ordinarily in the form of a coil, in which is circulated water to be heated. It has been customary in constructing instantaneous water heaters to provide a chamber adapted to receive heat from the burner and a coil surrounding such chamber and soldered thereto. Such a construction is attended with numerous decided disadvantages. Perhaps the foremost of these is the fact that due to expan- 'sion and contraction incident to operation of the heater the solder which fastens the coil to the heating chamber cracks in places, which reduces to a very great extent the heat transfer from the heating chamber to the coil and results not only in great reduction in thermal efficiency of the heater but also in possible or even probable burning out of the heating chamber.- The coil is relied upon to conduct heat away from the heating chamber at such a rate that the temperature of the heating chamber, even during capacity operation of the heater, will not rise beyond a temchamber is adapted to withstand.

perature which the material of the heating A further disadvantage of a heater structure of the type mentioned is that the coil at any place along the length thereof touches the heating chamber at only one point throughout the entire periphery of the coil as the coil is tangent to the outer surface of the heating chamber. Thesolder conducts heat from a limited area of the heating "chamber to a limited area of the coil, but even when the solder is intact the heat transfer from the heating chamber to the coil is quite limited.

Furthermore the heating chamber is relied upon, to some extent at least,as a support for the "coil, and when the solder cracks this support is rendered less effective. This results in weakening of the heater structure and such weakening may,

chamber, allowing sufficient freedom of movement of the coil relative to the clamping means to permit of unequal expansion and contraction of the heating chamber and coil such as will occur in operation of the heater. The clamping of the coil to the heating chamber may be effected in various ways. I prefer to provide sheet metal outside the coil and to fasten such sheet metal to the heating chamber intermediate the convolutions of the coil in any appropriate manner, as, for example, by'rivetin-g. The sheet metal may be in the form of individual strips disposed at various points along the coil, although I prefer to use one or more relatively large sheets corrugated to receive the convolutions of the coil and fitting against the outer surface of the heating chamber intermediate. such convolutions. The sheet or sheets may be fastened to the heating chamber at the portions thereof intermediate the convolution-s of the coil, and improved results are obtained even though such fastening is effected by soldering, as the temperature differential between the heating chamber and the coil is greater than that between the heating chamber and "the sheet or sheets. Even though the clamping means are soldered to the heating chamber this still has the-effect of clamping the coil to the heating chamber as the coil has appreciable free- 'dom of movement between the heating chamber and clamping means which it does not have if it is directly soldered to the heating-chamber.

Moreover, a greatly improved heat transfer from theheating chamber to the coil is effected contact ordinarily being throughout approximately half the area of the coil. As the sheet metal lies against the heating chamber intermediate'the convolutions of the coil, heat is conducted from the heating chamber into the sheet metal at such portions thereof which lie in intimate contact and thence from the sheet to thecoil throughout the relatively large area of the coil with which the sheet is in contact. Actually more heatwill be transmitted to the 0011 through 'the sheet than will be transmitted to the coil directly from the heating chamber despite the fact that the coil is in direct contact with the heating chamber.

Other details, objects and advantages of the "invention will become apparent as the following description of a present preferred embodiment thereof proceeds. 1

In the accompanying drawing I have shown a present preferred embodiment of the invention, in which Figures 1 and 2 are elevational views, taken at right angles to each other, of an instantaneous water heater but with parts forming no part of the present invention cut away for'the sake of clearness.

There. is provided a supporting frame 2 on which is mounted a-sheet metal structure 3, preferably of coppenforming a heating chamber.

The heating chamber-is in the shape of a trun cated pyramid, being open at the bottomand top.

Heat is supplied to the interior of the heating chamber by a burner 4 to which fuel, such as'a mixture of gas and air, is supplied through the fuelinlet 5. A pilot'burner is shown at 6; 'I have not shown an' automatic operating mecha- 'nism for the instantaneous heater as this forms no'part of the present invention. 7 The operating mechanism maybe, of any desired or well known construction.

7 V Surrounding the heating chamber is a coil! ;whi'ch,is ordinarily ofcopper. Cold water enters the coil .at 8 and passes round and round the heat-- ing chamber and finally through the'fin unit or superheater 9 at the top of the heating'chamber through which the products of combustion pass to the flue l0. Ifhehot water passes out through the pipe I I The heating chamberserves at least partially to support the coil. The coil lies di- -rectly in contact with the exterior of the heating chamber. Cooperating with each fiat sideof the heating chamber and disposed outside the coil is a c'orrugated'copper sheet l2 shaped to. receive within the corrugations thereof the convolutions of the coil and to lie flat against the heating 7 chamber intermediate such convolutionsr The I corrugations inf the sheets. are preferably so formed that the sheets closely embrace the con-' volutions of the'coil throughout approximately half of the circumference of the coil,' serving eifectively to transfer heat thereto. The sheets are'riveted to the heating chamber by: rivets I 3 suitably disposed between the convolutions of the f coil, preferably. in rows asshown- In place of therivet'sother fastening means such as solder,

welding, bo lts, etc., may be used.

The coil is free to moverelatively to the heating chamber within the sheets l2 upon'expansion and contractionpduringoperation of the heater and 1,there is practically no danger that thesheets will break loose from the heating chamber. v'Ihe heat differential betweenthe sheets and the heating'chamber isrelativelysmall. The'efliciencyof the'hea'ter is greatly increased, as heat passes readily through the heating chamber to the portions ofithe sheets lying flat thereagainst'interl. mediate the convolutionsof the coil and thence through thematerial of the sheets to the coil at y [the portions'of the sheets surrounding'the convolutions of the coil. Thus a heater having great' advantages from both the structuraland thermal standpoints is provided. #160 'While I have shownand described a present preferred, embodiment of the invention, it is to be distinctly understood that the same is not lim- ,Jited thereto but maybe otherwise variously em-,

bodied'within the scope of the following claims.

Iclaim:

- heat transmission means adapted to receive heat from one side from said heating means, conduit means for. containing a substanceto be heated disposed'at the opposite sideof said heat transtransmission means. 1

1. Heater structure, comprising heating means,

' Shell.

mission means, and means including a continuous metal sheet having successive portions extending in surface contact about successive portions of the conduit means and having successive portions mating in continuous contact with the heat transmission means for fastening the conduit means to the heat transmission means. I

2 Heater structure, comprising heating means, heat transmission means adaptedto receive heat.

from one side from said heating means, conduit means comprising a plurality of coils for containing a substance to be heated disposed atthe op- V positeside of said heat transmission means, and means including a continuous metal sheet in mating engagement with and substantially entirely covering the heat transmission means 'and the conduit means at said opposite side ofthe heat 3. I-Ieater structure, comprising heatingmeans, heat transmission means adapted to recelve heat frompne side from said heating means, conduit means comprising a plurality of coils forcontaining a substance to be heated disposed-at; the

opposite side of said heat transmission means, .and .means including a continuous. metal sheet in mating engagement with and substantially entirely covering the heat transmission means and:

the conduit means at said opposite side of the heattransmission means, said sheet. servingito fasten the conduit means to the heat transmis- 3o sion means and to transmit heat from the heat transmission means directly tov portions of the conduit means 1 remote from the heat transmission means. 1

4. In a heaterstructure, the combinationfof a tubular shell, a pipe coil having spaced turns and J in contact with the outer surface ofsaid shell,

2. plate having corrugated recesses to receive the 1 spaced turns 'ofthepipe coil, said plate mating ,in continuous surface contact with the shellbe-g. tween said corrugations,- andmeans for securing the'plate to the shell continuously along lines on r either side of eachof said corrugations.

,5. In a heaterstructure, the'combination of a 6 In a heater. structure, the combination of .a

tubular shell, a, pipe, coil having spaced turnss ofi and in contact withithe outer surface 'of said} 7 shell, and a plate securedin flatsurfacecontact with. the 'wall of the'shell intermediate of the turns of the pipe coil toprevent buckling of. the V wall of the shell .due tohigh temperatures.v

7. In a heaterstructure; the combination of a tubular shell,.a pipe coil arranged about said ,shell, and means for supporting the coil on the shell and. for preventing inward buckling 10f the V shell comprising a continuous metal member hay-Q .ing spaced corrugations engaging the t'urns'of the coil and intermediate portions secured to the" CHESTER D. jJjorIEs e CERTIFICATE OF CORRECTION.

Patent No. 2,051,215. August 18, 1956.

CHESTER D. JONES.

It is hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as "Pittsburgh Water Heater Corpo ration" whereas said name should have been Written and printed as Pittsburg Water Heater Corporation, of Pittsburgh, Pennsylvania, a corporation of Pennsylvania, as shown by the records of assignments of this office; and that the said Letters Patent should be re may conform to the record of the case in Signed and sealed this 20th day of October,

the Patent Office.

Leslie Frazer (Seal) Acting, Commissioner of Patents,

ad with this correction therein that the same

Images