US1827087A - Electric water heater - Google Patents

Description

Oct. 13, 1931. L. P. HYNES ELECTRIC WATER HEATER Filed May 20, 1926 3 Sheets-Sheet l INVENTOR LEE. P. HYNES 1 I .lll!!llillilllilllll idilllllililll!II|!IIIII!Illlilillllli rlillll ATTORNEY;

Oct. 13, 1931. L. P. HYNES ELECTRIC WATER HEATER Filed May 20, 1926 3 Sheets-Sheet 2 INVENTOR LEE P HYNES ATTORNEY a Li:

Oct. 13, 1931. P. HYNES ELECTRIC WATER HEATER Filed May 20, 1926 3 Sheets-Sheet 3 5 W a m 2 P 4 a W a. M. ;w

35% RM flbtow-e Patented Oct. 13, .1931

UNITED STATES PATENT OFFICE.

LEE P. HYNES, OIALBANY, NEW YORK, ABBIGNOB TO m & cox ELECTRIC COR- PORATION, OF ALZBLKY, NEW YORK, A CORPORATION OF NEW YORK ELECTRIC WATER 3mm Application fled Kay 50,

- terminal block with jumpers connected for (a) heater units in multiple (b) heater units in series;

Figs. 7 and 8 show means for inducing local circulation.

My invention relates to a hot-water tank wherein it is desired to maintain a constant supply of hot water at a given temperaturesay'160 degrees F. This water is to be kept hot automatically by electric heaters and I have devised a heater construction which, so

- far as I am aware, is novel and of marked utility, while I have also devised an electrical system of connections and control which I also believe is of equal novelty and merit.

Referring to Fig. 2 of the drawings, C represents a cylindrical water tank of sheet metal with a concave head at the bottom and a convex head at the top. This tank C is contained in an outside metal shell or casing'D and is surrounded on all sides with a packing of heat-insulating material such as sheet cork or rock wool. Within the tank are three tubes X, Y and Z extending from the lower concave head up through the upper convex head and then through the insulation above the tank to or near the bottom of the cover 1 of much practical importance. In the two larger tubes Y and X are the electric heaterelements A and B, which are entered into the tubes from above by removing the lid or cover of the casing, and are suspended in the tubes near the lower ends thereof by the elec- 1828. Serial No. 110,480.

tric conductors which carry the current to the heaters. Thus the heater elements may be inserted or removed, or their vertical positions changed, if desired, without disturbing the water pipes or connections. They are metal-cased heaters and fit snugly in the tubes to provide ample heat conductivity to the water without appreciable intervention of air insulation.

The thermostat is also suspended in its tube Z by its electric connections, so that it may be readily inserted or removed, and its vertical position may be changed, if desired.

The heaters A and Bare appreciably shorter than the respective tubes Y and X in which they are located, so as to provide a hot air space of substantial length and volume above the heating elements when each element is at the bottom of its tube. By means of this arrangement the tubes are heated throughout their lengths to a high temperature and thereby greatly aid in distributing the heat over a large area within the body of water.

Another important advantage of the relatively long tube is that each heater element may be elevated to any desired vertical position, so that while the same total heat is communicated to the water in the tank, the effective heating area will be varied in accordance with the position of the heater element. Inasmuch as the Water below the position of the heater element will not become appreciably heated, the smaller quantity of Water surrounding the heater element and extending above it will be more quickly heated.

Thus, this design provides a very flexible means of readily varying the intensity and rate of heating, and the total volume of water being heated.

An important advantage resulting from changing the vertical position of the thermostat within its tube Z is that provision is made for setting the thermostat at a point said heating-up periods, in order to make them occur at off-peak times in the loading of the electrical supply stations. For example, in a specific case, when the bottom of the thermostat was set thirty inches below the to of the tank, it wouldrstart the reheating a er five gallons of hot water had been drawn off, but when set ten inches from the top, it would not start the reheating until after eighteen gallons had been drawn off. So, if in a given time-say twelve hours one household used five gallons of hot water, its thermostat should be set thirty inches down; but for a household that used eighteen gallons in the specified time, its thermostat should be set ten inches down. Thus, by adjusting the position of the thermostat in any particular tank with respect to the heating duty required of it within the predetermined period, that particular tank may be made to perform its particular assigned heating-up duty at any desired time of day withoutresort to a clock-switch, or any other artifice such as is normally employed for controlling a timed operation. In addition to the above, if the heater elements should be adjusted to higher positions than those shown in the drawings, it is important that the position of the thermostat be correspondingly changed so that it will not occupy a plane below the middle portions of theheater elements. Thus I the thermostat and the'heater elements may be maintained in the proper relative position necessary to insure maximum operating efficiency.

On one side of the casing above the tubes aforesaid is the hand switch F and its association tell-tale lamp, both of which may obviously be located at any other convenient point of control. On the under side of the casing lid and seated on plate S is the terminal block P at which the several circuits are connected and distributed, as shown in Figs. 3, 5 and 6, also the contactor block '1" shown in detail in Fig. 4.

Turning to Figs. 3, 4, 5 and 6, F is the box containing the hand switch G by which the apparatus is put into and out of action while beside it is the tell-tale lamp H, which remains lighted while the heaters are on, but goes out when they are cut off either manually or automatically. The switch G merely closes a preliminary circuit, distinguished in the diagrams by single-barbed arrows, which may be traced as follows, starting from the line terminal 1 in Fig. 4. Thence it goes to the post 1 on the terminal-block Q, (shown best in the enlarged view of Fig. 5) to post 9, thermostat K post 10, hand-switch G, post 11, post 4, thence back to post 4 on the contactor block T of Fig. 4 to the magnet J and finally to the opposite line terminal.

The magnet J then (acts, provided the aforesaid preliminary circuit is closed at hand-switch G and also at the thermostat K-the latter being closed so long as the temperature of the surrounding water is below the predetermined point, say 160 degrees F, but opens whenever the temperature exceeds that point. The magnet J, when it acts, closes the main switch I and holds it closed so long as it remains energizedthat is to say, as long as the hand-switch G and the thermostat K are both closed. The heator circuit which has now been closed by the said main switch I is distinguished in the diagram by double-barbed arrows and goes from post 2 on the contactor block T to post 2 on the terminal block Q. Thence it goes to post 5 and then through the heaters A and B either in multiple for a voltage of 110, or in series for a voltage of 220. In Fig. 5 the posts 5 and 8 are connected by a jumper S and a similar jumper S connects posts 6 and 7. That arrangement puts the heaters A and B in multiple. In Fig. 6 the two jumpers S, S, joined end to end, connect the posts 6 and 8, that arrangement putting the two heaters in series.

From post 5 (Figs. 3 and 5) one branch of the heater circuit goes to heater A, to post 6, to post 7, while the other branch goes to post 8, to heater B, to past 7. From post 7 the circuit goes to post 3 of the terminal block Q, to post 3 of the contactor block T, to switch I and negative line-terminal. In Fig. 6, the corresponding heater circuit goes from post 5 aforesaid, to heater A, to post 6, to post 8, to heater-B, to post 7 and thence as before to the negative line terminal, thereby putting the two heaters in series for the hlgher voltage.

It will be noted. however, that the lamp circuit is connected between posts 5 and 6, and therefore as shown in Figure 5 is in multiple with the circuit of heater A, and as shown in Fig. 6, is in series with the circuit of heater B, while the last mentioned heater is in operation. By means of this arrangement it is possible to maintain a constant voltage on the lamp circuit irrespective of the voltage of the line with which the heater is to be connected. In operation it is only necessary to close hand-switch G to put the apparatus in action. At that time the thermostat is closed, the water in the tank being cold. The switch I will be closed by magnet J and the heater brought into circuit. It will remain in circuit, giving heat to the water until the determined temperature is reached, when the thermostat will open the preliminary circuit through ma et K and heater switch I will open. So ong as the hand switch G is closed the apparatus will continue ready for action. Whenever the water temperature falls below the determined point, as, for instance, when hot water is drawn off and cold water flows in to replace it, the thermostat will close and restart the heaters.

By the above-described means I provide a er coils to act on small practical hotwater supgly tank for houseold or industrial use. or summer homes, or in remote localities, wherever electric current is available, it may be profitably mstalled. It is compact and self-contained and requires only the connection of the inlet and outlet water-pipes and the electric leads. The heating units may be remove and replaced without draining the tank or disturbing the water connections. The insulation prevents radiation of heat and will maintain a tank full of hot water for a long time without expenditure of current, and the cost of operation is only in proportion to the amount of hot water actually used.

It will be observed, however, that in the arrangement described above there is a limit to the amount of hot water that can be drawn off at any one time. Assuming that the tank is full of heated water, which is at the rescribed temperature in the neighborhoo of the thermostat and at approximately the same temperature in other parts of the tank, then a heavy draft of hot water from the top of the tank will admit a corresponding inflow of cold water at the bottom, this inflow beingv at a rate greater than the in stantaneous heating capacity of the heater. In consequence, no more hotwater will be available until the entire body of water in the tank has been again raised in temperature. That will take time, although when a definite temperature is reached, there will be a whole tankful of water at that temperature. I materially modify that condition by means of an arrangement which will enable the heatortions of water in succession, thereby provlding very quickly a smaller amount of high-temperature water,

instead of a larger amount of lower-temperature water in a longer time. I accomplish this by providing a separator or, shield that will enclose a limited amount of water around the heater and which is also open at top and bottom. The limited amount of water within this shield or separator will become heated first and as it is so heated will rise towards the top of the tank and thereby segregate itself above the body of cooler water outside the shield. As a result this limited body of highly heated water accumulates at the top of the tank and is ready for use long before the entire body of water could be raised to that same temperature. One form of thisdevice is shown in Fig. 7 wherein one or more of the heater-containing tubes-for example, tube X-is surrounded by a shorter tube X of larger diameter. This forms a limited space outside of tube X and inside of tube X wherein the limited amount of water is heated rapidly to a much higher temperature than the body of water outside of tube X and rises by its lower weight to the top of the tank. The upward flow of the water through the tube X is slightly retarded by the restricother means,

(1 in the tank to be heated. In Fig. 8 the heat- .er-tubes are grouped together on one side of tank and open at their u cylindrical pressure tank supported in a vertion covering the top of the tank,

tank, heat insulation completely enclosing 12 tion to flow caused by the spider X, or

for holding the tu es X and X in s aced relation. Thus there quickly accumu ates a layer of hot water in the top part of the tank from which part the water may be drawn off by the common outflow pipe without waiting for the entire body of water the tank and the shield or separator X is ex- 76 tended as a chord across the tank toseparate- 1y enclosethe entire group of heater-tubes together with a. limited body of water that is heated more quickly, as I i have described than the remainder of the water and rises to the top of the tank as heretofore explained.

While I have described and claimed my de vice as a hot-water tank, it may obviously be used for any other liquid that needs to be stored at a maintained temperature.

What I claim as new and desire to secure by Letters Patent is:

1. An electric water heater com rising a tank, heatinsulation completely enclbsing the tank, water tight tubes located within said per ends outside of the tank and the insulation, electric heating elements located within the res ective tubes, saidheating elements being 0 appreciably shorter length'than said tubes, so as to provide a heating space of substantial length and volume above the positions of the heater ele-* ments, a thermostatpositioned to be influenced by the temperature of the water within the tank and controlling the circuit to the 100 heating elements, and means for supporting the thermostat within the tank.

2. Anelectric water heater comprising a tical position, heat insulation completely enclosing said tank, a plurality of water tight heater tubes, and a thermostat tube all extending through and secured to the upper. end wall .of said tank, heater elements located within the heater tubes, and a thermostat located within the thermostat tube and controlling the circuits to said heater elements, the upper ends of said tubes being normally open and passed through the insulaso as to permit access to the heater and thermostat ele ments without necessitating removal of said insulation covering. 3. An electric water heater comprising a the same, water tight tubes located within the said tank, electric heating elements located within the respective tubes, said heating elements being of appreciably shorter length than the tubes, suspension means for the heater elements, so that they may be supported atdiflt'erent vertical positions Within the tubes so as to vary the intensity and rate of heating of the water and also to vary the total of volume of water being heated, and a 13.0

same, water tight tubes thermostat located at a position within said tank to be influenced by the temperature of the water and controlling the circuits to the 5 heating elements.

4:. An electric water heater comprising a tank, heat insulation completely enclosing the located within said tank and opening at their upper ends outside of the tank so that access may be had to the interior of said tubes without necessitating removal of said insulation, conductor wires depending into said tubes, electric heaters connected with and suspended from said Wires so that the heater elements may be supported at different vertical positions within said tubes to vary the intensity and rate of heating of the water and also to vary the total volume of water being heated, and a thermostat located at a position within said tank to be influenced by the temperature of the water and controlling the circuits to the heating elements.

5. An electric water heater comprising a tank, heat insulation completely enclosing the same, Water tight heater tubes located Within said tank, a thermostat tube also located within said tank, said tubes opening at their upper ends outside of the tank so that access may be had to the interior of the tubes without necessitating removal of said insulation, conductor wires depending into said heater tubes, electric heaters connected with and suspended from said wires so that the heater elements may be supported at different vertical positions within said tubes to vary the intensity and rate of heating and the total volume of water being heated, a thermostat located Within the thermostat tube and controlling the circuits and the heating elements, and conductor wires depending into said thermostat tube and suspending the thermostat within its tube.

6. An electric water heating system comprising a closed vertical pressure tank, heat insulation completely surrounding said tank, vertical water tight tubes extending upwardly through the top portion of said insulation, electric heaters Within said tubes, connectors leading from the heaters through the upper ends of said tubes into a junction chamber, a thermostat so located with relation to the heaters that there are two separate columns of water between them, and means for causing one ofsaid columns of water to have a more rapid upward convection movement than the other when the heaters are in operation.

7. An electric water heater comprising a vertical pressure tank, a water heating tube within sad tank, said tube being closed against admission of water thereinto, a heater element within said tube, water circulating means cooperatingwith said tube to deliver heated water to a position adjacent the top of the tank, and a thermostat gov.- I

vertical pressure tank, a

erning said heater element, said thermostat being movably mounted so that the operation of the heater may be controlled by temperature of the water at different levels.

8. An electric water heater comprising a vertical pressure tank, a water heating tube Within said tank, said tube being closed against admission of Water thereinto, a heater element movably mounted within said tube so as to be supported at various elevations therein, to vary the intensity and rate of heating and total volume of water to be heated, water circulating means cooperating with said tube to deliver heated water to a position adjacent the to of the tank, and a thermostat governing said heater element.

9. An electric water heater comprising a plurality of water heating tubes within said tank, said tubes beng closed against admission of water thereinto, heater elements within the respective tubes, means associated with one of said tubes for insuring a rapid convection movement of a column of water to the top of the tank, and a thermostat governing said heater elements, said thermostat being movably mounted so that the operation of the heater may be controlled by the temperature of the water at different levels.

10. A11 vertical pressure tank, a Water heating tube within, said tank, said tube being closed against admission of water thereinto, a

LEE P. HYN ES.

electric water heater comprising a

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