Electric fluid heater

March 22, 1932.

W. RICHARDSON

1,850,156

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Patented Mar. 22, 1932

1,850,156

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WHIM MOU1MO,, 0, ATLANTA, GEORGIA, ASSIGNOR TO GBOBGS STS1NGRUBBH OF HUNTSVuuLE, ALABAMA

ELECTRIC FLUID HEATER

Application· filed April 9, 1929. Serial No. 353,718.

This invention relates to electric fluid heaters, and more particularly to heaters adapted lor supplying hot water for domestic purposes.

ϋ While my invention is capable of use in many different relations, it is especially designed as an attachment for electric cooking langes, and is intended to be connected to a water system in the manner shown in the us copending application Serial No. 353719 now Patent Number 1,813,124 of George otemgruber and myself, filed of even date herewith.

The objects of the invention are to provide is a water heater which shall be cheap in construction and efficient in operation, and which may serve either as a circulation heater for a stand boiler or as a semi-instantaneous heater for quickly supplying relatively small 20 quantities of hot water.

In order that the invention may be readily understood, reference is had to the accompanying drawings, forming part of this specification, and in which:— _ Figure 1 is a sectional plan view of my improved heater;

Figure 2 is an end view thereof, partly in section, and partly in elevation;

Figure 3 is a side elevation of one of the no heating elements, parts being broken away and one of the end walls of the casinp- beinoshown in section; and °

Figure 4 is a view partially in side elevation and partially in section of the heatinp- coil 35 itself, and the support therefor.

Referring to the drawings in detail, my improved heater is preferably formed of sheet metal and isjof relatively shallow rectangular shape. It comprises a sheet 1 bent ⁴⁰ around, as shown in Figure 2, to form top, bottom and side walls, the top and bottom walls preferably being flat, as'shown. Into each end of this body structure is inserted a flanged end plate 2, having flanges 3 welded ⁴⁵ or otherwise secured to the’edges of the body portion 1. Thus, a completely closed casing or box is formed. ' °

The top and bottom walls of the casing 50 ³¹⁶ °¹’ ⁴’^e&lt;-' together and thus prevented from bulging by means of partition strips 4, each preferably of channel shape and provided with flanges 5 welded or otherwise secured to the top and bottom walls, lhese partition strips also serve as baffle piates to direct the flow of fluid, as herein- « alver explained, and to this end, they are arranged in parallel relation with their ends alternately spaced from the opposite end wails ox the casing so as to provide a zig-zaopassage. ^s

In order co heat the fluid in its passage through the casing and around the baffle plates 4, J provide a plurality of heating units, each of which comprises a tube 6, preffi erably formeci of copper or other good con- _C5Quoting material. These tubes are arranged in spaced parallel relation and are interposed between the baffle plates 4, as. clearly shown in η igure 1. Tne tubes extend through openings in the encl plates 2 of the casing'and 70 have their ends rolled over or expanded into these end plates, as indicated at 6% in the same manner as boiler tubes are set into tube sheets. Other methods of securing the tubes, as, for example, by soldering or brazing’ Ίΰ can be employed, if desired. In order to assist in the circulation of the fluid and also to aid in imparting heat thereto, each of the tubes 6 is preferably provided on its upper side with a longitudinal rib or fin 7. As iiq clearly shown in Figure 2, the tubes 6 are set lelativeiy near the bottom of the casing, out out of contact therewith, and the fins 7 extend^ almost, but not entirely, to the top wail of the casing. Thus, when these tubes 33 are heated, as hereinafter described, there is a tendency tor the liquid adjacent thereto to move or circulate locally and laterally, in planes transverse to the direction of flow, as indicated by the arrows in Figure 2. At SO the same time, the liquid may pass between the tuoes 6 and the bottom of the casing, and oetuveen the nns i and the top of the casino·.

lhe tubes are heated by means of electric heating elements, each of which consists of a tube or spool 8 made of porcelain or other insulating rerractory material and preferably provided with enlarged ends or heads 8“ of a size to snugly fit within the tubes. Wound on this spool is a heating coil 9 of

1,850,156 suitable material, and the ends of this coil are brought out through the hollow center of the spool, as clearly shown in Figure 4, so that the coils of the several heaters may be _r properly connected. As clearly shown in ° Figure 1, these coils are pr-eferablj⁷ connected in series, the current entering, say, tnrough the terminal 14 and passing successively through the coils of the several heating units . θ through the end connections 15 and thence out through the terminal 16.

The heating elements comprising. the spools 8 and coils 9 are inserted in the interior of the tubes, as clearly shown in Figure ₁₅ 3, the coils having first been embedded and covered with a coating 10 of refractory cement of any suitable character, this cement being applied to the body of the spool until it is flush with the, heads 8^a thereof. In other 20 words, the cement fills the space between the body of the spool and tne interior or tne tube, thus excluding air and thoroughly insulating the heating coil and preventing grounding, should it become broken.

By reference to Figure 1, it will be observed that the ends 2 of the casing are set back a slight distance from the edges of the body portion, so as to form recesses,, and these recesses are preferably filled with a 30 heat insulating cement, as indicated at 11.

This not only/overs and protects the connecting wires 15, but also seals the open ends of the tubes and prevents the access of air thereto. .

Liquid enters the heater through a pipe 12, adapted to be connected to any suitable source. This pipe 12 is preferably located near the bottom of the casing, and at one side thereof, and, as shown, in Figure 1, is 40 extended inwardly for nearly the length of the casing, and provided with a plurality or small discharge holes or openings 12% so as to distribute the incoming liquid along the length of the first heating unit.

The liquid leaves the heater through an outlet pipe 13, and this, as clearly shown in Figure 2, is set at the opposite side of the casing and at a point near the top thereof.

From the foregoing, it will be seen that ⁵⁰ liquid entering the casing through the orifice 12^a of the inlet pipe 12 is delivered against the first heating unit and flows thence around the baffle plates 4 and along and around the successive heating units until it is. finally discharged through the pipe 13. It is obvious that the liquid in its travel is brought into contact with a very large heating.surface and this, combined with the local circu60 lation which is set up adjacent the tubes, as hereinbefore described, results in an extremely rapid heating of the liquid. Thus, a few minutes after current is turned on, hot water may be drawn from the pipe 13. ss Otherwise? the pipes 12 and 13 may be connected to a stand boiler and will heat the same by circulation in the usual manner.