US2211380A - Electric heater for liquids - Google Patents

Description

B. A. MIKKELSON ELECTRIC HEATER FORYLIQUIDS Filed May 14, 1958 Aug. 13, 1940.

3mm/m Patented Aug. 13, 1940 'Unire www garant ortica ELECTRIC HEATER FR LIQUDS Berent A. Miklielson, Seattle, Wash.

Application May 14,

1 Ciaim.

The invention relates to electric heaters for liquids, such as water and oil, and has for an object the provision of an inexpensive device of this description useful in barber shops, homes 5 and other places for the heating of water or as a pre-heater for the oil fed to oil burners, said heater being of comparatively small or portable nature connectible to the ordinary light socket and operating efficiently at small cost for current.

The invention consists in the novel construction and combinations of parts as hereinafter set forth in the claim.

In the accompanying drawing:

Figure l is a central longitudinal section of the invention, and r Figure 2 is a cross section on the line 2-4-2, Figure 1.

In the drawing, the numeral I designates a tubular cylindrical metallic casing, having a contracted forward end 2, provided with a central aperture 3, a cylindrical heating element il being located within said casing and having an external diameter less than the internal diameter of the casing to provide a circumferential space 6 and an internal diameter greater than the diameter of said aperture, a thermal insulation lling of asbestos 'l being provided for said space. The heating element has a central bore 5.

This heating element comprises a porcelain tube having a resistance wire coil 8, surrounding and in contact with said tube, and a porcelain paste exterior covering 9 for said wire coil, said porcelain paste covering serving to insulate the coils from one another and to iirmly secure the coils to the porcelain tube so that they cannot get out of place at any temperature to which the coils may be raised and cause short circuiting.

The casing I has a lateral aperture I located near the rear end thereof and provided with an 40 eXteriorly threaded bushing I3, a junction box M being secured to sai-d bushing by lock nuts l5. The lead-in wires I2 for the resistance wire coil 8 are spliced within the junction boX and extend through the bushing-lined aperture I within said circumferential space 6, being secured at their inner ends to the screws l I of the metallic terminal bands II of the porcelain tube il, the opposite ends of the resistance wire coil 8 being also secured to the screws of said bands. A removable closure I8 fits within the rear end of the casing I, abuts against the rear end of the porcelain tube 4I, has a central aperture I8 of the same size as that of the forward end of said casing and closes in the rear end of the circumferential space 6. The closure I8 is held in Cil 1938, Serial No. 208,004

(Cl. 21S- 39) place by cotter pins I9 engaging perforations of the side wall of said casing.

In assembling the parts, the heating element d is inserted within the open rear end of the casing E until it contacts the contracted forward end 2 of said casing, the lead-in wires I2 being then manipulated through the bushing-lined lateral aperture of the casing into the junction boX by inserting the lingers of one hand through the open rear end of the casing, said lateral aperture being located near the rear end of the casing to admit of such manipulation. The circumferential space l is then packed with the loose asbestos thermal insulating material l, thereby holding the tubular heating element d in central ized position within the casing, the removable closure i3 fitting within the rear end of the casing and having a central aperture I8 being then placed in position to abut against the rear end oi said heating element and to close in the rear end of the thermal insulation packed circumferential space 6, said removable closure iS requiring nothing more than the cotter pins i9 engaging lateral perforations of the casing to hold it in place.

Ilhe heater is adapted to have the pipe I'l for water cr oil to be heated extend slidably through the bore of the heating element or porcelain tube and the apertures of the ends oi the casing. Due to the fact that the porcelain tube 4 of the heating element has an internal diameter greater than the apertures of the casing ends, a circumferential air space is provided between the pipe l'i and said porcelain tube, thereby tending to protect the pipe il from being supercially fused or roughened by the heat and avoiding any such adherence between the said porcelain tube and said pipe as would interfere with free movement of the heater relative to said pipe.

The tubular casing i may be either cylindrical or other suitable shape, that is to say it may be square in cross section. The porcelain tube ll may be spirally grooved to receive the coils of the resistance wire coil 8.

The heating device is held from rotation on the pipe l i for conv-eying the oil or water to be heated by electrical cable 2li carrying the lead-in wires l2, said cable having suitable lock-nut connection with the junction box I4 and with the electrical outlet.

I claim:

In an electric heater for liquids, a tubular casing having a contracted forward end provided with a central aperture, a heating element comprising a porcelain tube having a resistance wire thermal insulation lling for said circumferential space adapted to hold said tube central of said casing, a removable closure for the rear end of said casing, abutting against the rear end of said tube, closing in the rear end of said circumferential space and having a central aperture of the same size as that of said rst named aperture, said heater being adapted to provi-de a circumferential air space between said tube and the pipe for conveying the liquid to be heated and engaged with the apertures of said casing ends, thereby tending to protect said pipe from being injured by the heat and to render the heater freely movable at all times relative to said pipe.

BEREN'I A. MIKKELSON.

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