US 2448669 A
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Description (OCR text may contain errors)
Sept. 7, 1948. GREEN, JR 2,448,669
ELECTRIC HEATER FOR TANKS Filed Dec. 22, 1945 2 Sheets-Sheet l Sept. 7, 1948. T. F. GREEN, JR V r 2,443,569
ELECTRIC HEATER FOR TANKS Filed Dec. 22, 1945 2 Sheets-Sheet 2 l l\ k Q 3 [Fara e71,/7
Patented Sept. 7, 1948 UNITE D STAT E S PATENT OF F I CE ELECTRIC HEATER; FOR TANKS ThomasF. Green, J r., OrmondQBeach, Fla.
Application December 22, 19.45,- Serial. No; 536 5816 1 Claim. 1
This invention relates to electric heating. elements for use in liquid boilers.
An object of this invention isto provide. an improved heater for mountinginside aboiler, which.
is; of such constructionthat. the heating element can readily be removed in the eventany portion thereof becomes damaged.
Another object of this invention is to provide a heating unit of this kind wherein the-resistance coils are mounted in an extruded. ceramic core which is loosely positioned in' a closed casing so that in the event the coil becomes broken it can be readily replaced in the ceramic core or if the core becomes broken anew core can readily-be inserted in the housing or cover for the unit.
A further object of this invention is to provide a unit of this kind which is formed with coupling or mounting meansat its outer endso that theunit can'be mounted in various types of boilers or hot water heaters;
A further object of'this invention is to provide a heating unit of this kind which is of such construction that. the core or the coil can readily be replaced without draining the tank.
A further objectof this invention is to provide an improved heating unit which is of such construction that it can be producedat a lower cost than units of this kind at present available and at the same time will permit ready replacement of any portion thereof.
To the foregoing objects, and others which may hereinafter more fully appear, theinvention consistsof the. novel construction, combination and arrangement'of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations, and modifications may be resorted to which fall within the scope of the invention as claimed.
In the drawings:
Figure 1 is a detail side elevation of a heating unit constructed according to an embodiment of this invention,
Figure 2 is a longitudinal section partly broken away of the device,
Figure 3 is a sectional view taken on the line 33 of Figure 2,
Figure 4 is a detail side elevation of a unit similar to that shown in Figure 1 and 2 wherein the housing is welded to the side of the tank,
Figure 5 is an outer end elevation of the unit shown in Figure 4,
Figure 6 is a detail side elevation of another modification of this invention,
Figure 7 is a longitudinal section partly broken away of the unit shown in Figure 6, and
Figure 8 is an inner end elevation of the plug used with the unit shown in Figures 6 and 7.
Referring to the drawings and first to Figures 1, 2 and 3, the numeral 10 designates generally 21 an elongated tubular'housing which is provided witha: closed inner end. I I. The'outer end of the housing H1 is open and a mounting plate I2 is welded; brazed or otherwise firmly secured, to the l housing H! at a point, inwardly from the outer end thereof, asindicated at 13, and the plate I2 is adapted to be securedto the side wall Id of a boiler by fastening members [5. Preferably a sealing, gasket IB'is interposedbetween the plate t2: and the side wall. M of the boiler. The housing Ill'hasloosely mounted therein an elongated ceramic core IT.
The corel'l is formed with a plurality of longitudinally extendingbores I8 positioned about the center thereof and is also formed with a central bore I 9. There is an electric resistance coil 20 in each, of the bores |81 and in practice the coils of the resistance member 20 are formed integral with each" other, sothat a single length of resistancewiremay beused which is extended through the bores t8; and then bent about the ends of the core I! in order that onlytwo ends 2| and 22 will: be provided for connection with a pair of terminalposts, 23 and 24 respectively.
An outer plug; or cap 25. which may be formed oft ceramicmaterial engages within the outer end of; the housing. Ill being removably secured thereinby'means of a; bolt 26- extending diametrically through. the outer. end of the housing and of the plug; 25:. The plug; 25zisformed at its inner side with: an annular chamber 21 within which the ends: of the resistance Wires are adapted to engage whereby the wires may be readily connected to the terminal members 23 and 24. An inner cap 28;.whi-ch-mayalso:beformed of ceramic material, also engages overthe inner end of the core I! being formed with an annular chamber 29 whereby the inner ends of the coils of the resistance wire 20 may be extended from one bore 18 to an adjacent bore. A securing bolt 30 extends through the central bore [9 having an inner head 3! which is counter-sunk in the inner cap 28 and the outer end of the bolt 30 is threaded into the center of the plug 25. In the formation of the core I! this core is preferably formed by extruding the ceramic material, so as to provide a round core which is also formed with the circumferentially spaced apart bores or openings for the resistance coils and it is also formed with a central bore for receiving the clamping bolt 30.
Referring now to Figure 4, there is disclosed a heating unit which is similar in every respect to the heating unit shown in Figure l, with the exception that the mounting plate I2 is eliminated and the housing ill is secured in the side wall M of the boiler by means of brazing or welding as indicated at 32. In other respects the heating unit Ina shown in Figure 4 is similar to the construction shown in Figures 1, 2 and 3.
Referring now to Figures 6, 7 and 8, there is disclosed a heating unit which embodies a construction that may be threaded into the side wall of a boiler where the wall is heavy enough to form threads or where a reinforcing bushing is secured to the side wall for receiving a heating unit of this type. The heating unit shown in Figures 6, 7 and 8 includes a tubular housing 33, which is closed by a curved wall 34 at its inner end and is open at its outer end. The tubular member 33 is tightly secured within the inner end of an externally threaded nipple 35 which is formed with a nut head 36. A ceramic core 31 formed with circumferentially spaced apart bores 38 for receiving resistance coils 39 is disposed within the tubular member 33 and extends through the nipple 35. The nut head 36 is provided with an annular chamber 49 within which a ceramic plug M is adapted to be positioned. The plug 4| is removably secured in the counterb-ore 40 by means of a set screw 42. The plug 4| has extending therethrough a pair of terminal members 43 and 4 3- which are adapted tobe connected to the two ends of the heat resistance coils 39. The plug il at its inner end is formed with an annular chamber 45 within which the inner ends 36 and 4'! of the terminal members 43 and M are adapted to engage so that the outer ends of the heat resistance coils 39 may be left relatively long in order that the plug All may be partially withdrawn from the head 36 without pulling out the core 31.
In the use of this heating unit where the tank is of such construction that the housing for the unit can be welded to the side wall of the tank, the construction shown in Figure 4 is used or if the tank wall is relatively thick, the construction shown in Figures 1, 2 and 3 may be used. Where a bushing is provided in the side wall of the tank havin interior threads, the construction shown in Figures 6, '7 and 8 is used. In the event any portion of the heating unit becomes broken or damaged the core including the heat resistance coils may be removed as a unit without removing the housing which is sealed with respect to the boiler. Where the construction shown in Figures 1, 2 and 3 is used, the core may be removed by withdrawing the locking bolt 26. The core can then be pulled out of the sealed housing In and any portion of the unit including the ceramic core or the heat resistance coil can be replaced. Through the provision of an extruded ceramic core the manufacturing cost of the heating unit 4 is very considerably reduced and by providing the heat resistance coil, which is loosely mounted within the bores of the ceramic core, the resistance coil can easily be replaced without damage to the ceramic core. It will be apparent from the foregoing that this unit can be easily and quickly and cheaply repaired or replaced and that once the housing has been tightly secured to the side -wall of the tank the housing need not be removed or disturbed in the event any portion of the unit becomes unserviceable.
The heater shown in Figures 6, 7 and 8 may be used in either boilers or tanks, or in pipes and pipe fittings such as are used in instantaneous types of heaters.
The exact configuration illustrated is regarded as the optimum, but some of the desirable results inherent in this disclosure may be obtained by various slight modifications including some departure from the exact configuraton shown, and it is therefore requested that the scope of the invention should be regarded as limited only by the terms of the claim.
What I claim is:
A tank heater comprising a tubular housing for extension into a tank, a closed inner end on said housing, a ceramic core loosely disposed in said housing and formed with a plurality of circumferentially spaced apart bores, a resistance coil loosely disposed in said bores, a plug in the outer end of said housing, said plug formed with an annular recess on the inner end thereof adj acent the outer end of said core, a pair of terminals carried by said plug extending therethrough and into said recess and connected to said coil, and means removably securing said plug in said housing.
' THOMAS F. GREEN, JR.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date Re. 17,093 Torriani Oct. 2, 1928 1,394,518 Abbott Oct. 25, 1921 1,670,437 Campbell May 22, 1928 1,688,796 Baker Oct. 23, 1928 1,715,287 Head May 28, 1929 2,069,348 Young Feb. 2, 1937