US1718866A

US1718866A - Liquid heater

Info

Publication number: US1718866A
Application number: US284534A
Authority: US
Inventors: Barnett W Macy
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-06-11
Filing date: 1928-06-11
Publication date: 1929-06-25
Anticipated expiration: 1946-06-25

Description

June 25, B MA 1,718,866

LIQUID HEATER Filed June 11, 1928 INVENTOR @uwnQ/W BY M da ATTORNEY Patented June 25, 1929.

UNITED STATES BARNETT W. MACY, 0F JACKSONVILLE, FLORIDA. i

LIQUID HEATER.

Application filed June 11,

This invention relates to improvements in liquid heaters, and it consists of the constructions, combinations and arrangements herein described and claimed.

An object of the invention is to provide a heater in which hot water will be stored for use when required, the heating of the water being done by an electrical unit which is subject to the control of a heated column of oil, the opening and closing of a thermostat and of an electrical circuit associated there- .with, being directly dependent upon the temperature of said column of oil.

Another object of the invention is to provide a special provision for a further opening of the electrical circuit in case the current should be turned on while the storage tank is dry,.this provision relating to the heated column of oil, mentioned before, and

to the particular disposition of a control tube in which the thermostat is located.

Other objects and advantages appear in the following specification, reference being had to the accompanying drawing in which Figure 1 is a central vertical section of the improved water heater,

Figure 2 is a sectional view of the heating unit, port-ions being shown in elevation, Figure 3 is a cross section taken on the line 33 of Figure 2.

The invention disclosed in this application is an improvement on the liquid heater disclosed in application No. 3, Serial No. 282,530, filed June 4, 1928 by Barnett \V. Macy, one of the features being a branch of the heater tube that contains the thermostat, said branch being located medially of the heater tube so that a close regulation of the temperature of the volume of'water in the reservoir may be obtained within approximately five degrees. A feature incidental to the construction is the disposition of the thermostat in the outer end of said branch at a point outside of the heater, the thermostat therefor being accessible so that any necessary repair or replacement may readily be made without dismemhering the heating unit.

A tank 1, of any suitable type, provides a reservoir in which hot water is to be stored in readiness for use. To that end the tank may be made as large or as small as specific requirements may demand. The tank has a heavy sheathing of insulation 2, this sheathing being held in place by an outside jacket 3. A pipe or tube 4. is introduced into the sealed closure 5.

1928. Serial No. 284,534.

3. The tube 4 may be, and preferably is,

welded to the tank 1 as the place where it enters the top, so that the tube 4 is prac 'tically a part of the storage tank.

The tube 4 extends to a point close to the bottom of the tank 1 where the end has a The tube contains oil which assumes a level above the orifice of a control tube 6. This tube is smaller in diameter than the heater tube 4. It extends at right angles to the tube 4, although there is no restriction on the particular disposition of the control tube, and inasmuch as the control tube is a branch of the heater tube it follows that it contains oil and that a thermostat 7 located in the control tube, is always immersed in oil. The thermostat maybe of any known construction.

Particular attention is directed to the fact that the control tube 6 is located medially of the heater tube 4. By so locating the control tube a closer regulation of the heating of the volume of water is obtained. The

scription of the operation. Location of the control tube elsewhere would not have the same effect, and the regulation of the heating of the water would be erratic. The control tube has two special functions, first: as an automatic regulator when. the tank 1 is full of water and, second: as a safety device in case the current is turned on when the tank is empty.

The heating unit, to which allusion has been made, is constructed as follows: a base plate 8 provides a top closure for the tube 4: as well as the sole support of the heating unit. Two terminal rods 9 and 10 extend from the base plate to a point of connection with a top spacer bar 11 of insulating material. Resistance wires .12 are threaded through holes in the bar 11, as well as Ehr'ough holes in a bottom insulating spacer Bushings 14 and 15 insulate the rods 9 and 10 from the plate 8. The latter also provides the base from which a'stud 16 depends. This stud passes through the plate 8 and the bars 11 and 13, the exposed ends being threaded to receive nuts 17 that hold the assembly together. The stud passes through upper and lower porcelain or other insulating sleeves l8 and 19 which serve to fii' the positions of the bars 11 and 13. A conreason for this is fully explained in the denector 2O suitably. carried b the lower sleeve 19, has screws 21 at whic 1 the ends of the resistance wires 12 are joined so as to complete a part of. the-circuit.

Insulating twine 22 is used to tie. the resistance wires 12 to the central insulating tube 19, the purpose being to hold the wire firmly in place and prevent it from sagging out of position. Threads 23 permit screwing the tube 4 into a connection ring 24. The plate 8 is temporarily attached to the ring 24 by machine screws 25. A knock out box 26 forms the upper terminal of the heating unit. It is here that the necessary connections with the rods 9 and 10 are 111a( i e. A conduit 27 joins the box 26'With'a control box 28 from which the thermostat is accessible. This control box will contain a switch S by which the current.

is turned on and off. A suitable drain 29 provides for emptying. the tank. Cold water is introduced at a pipe 30 and hot water may flow out of a pipe 31".

The operation is readily understood. .As has been emphasized already, the medial location of the control tube 6 in reference to the heater tube 4 is one of the important features. Assume, first, the caseof a full tank of cold water. 1

The thermostat setting is for 145 degrees (for example). Upon turning the current on at the switch S the effect of the electrical unit will be to heat the column of oil in the tube 4. The heat naturally rises so that the volume of water in the tank 1 begins heating at the top.

The heated zone extends downwardly until it reachesand passes the control tube 6. By the time that the water at the bottom of the tank 1 becomes preceptibly warm, the water surrounding the tube 6 will reach a temperature approximate the setting of the thermostat. It is then that the oil in the control tube 6 reaches the temperature at which the thermostat *3 will be operated thus opening the circuit and temporarily suspending the action of the heating unit;

At this point a further explanation must be made before the function of the control tube 6 is described as a safety device. The oil in. the tube 6 does not become heated. to the temperature of the column of oil in the tube 1 by the heating action of the resistance element, as might be supposed. The resistance element will heat the column of oil, and the heat units will assemble in the tube, but will not traverse the lateral column of oil in the tube lltis not until the water becomes sulhcicntly heated that heat is conducted to the lateral column of oil in the tube 6, and when suiiicicnt heat has been so conducted to the lateral oil column then the thermostat acts as already stated.

In other words, the lateral oil column in the tube 8 and the thermostat 7 operate by misses indirection. The principle is this: The vertical column of oil in the tube 4 is subject to becoming initially heated, always exceeding the temperature of the volume of water, but the temperature of the lateral column of oil in the control tube 6 is always the same as the temperature of the water surrounding the tube. A live degree drop in the surrounding temperature and of the lateral column of oil will serve to permit the thermostat to again cl5se and start the heating operation.

Assume, next, a condition in which the tank 1 is empty and the current is inadvertently turned on. It is now that the con-' trol tube 6 acts as a safety device for, were it not for the function of the control tube at this time, the electrical heating unit would burn out. The vertical column of oil will heat rapidly, and as the zone of heat travels downwardly it will reach the control tube (Sand heat the lateral column of oil, there being no surrounding medium totake the heat away.

The heating of the lateral column will soon become so great as to operate the thermostat? The opening of the circuit will follow.

It has been stated that the location of the control tube 6 at any point other than stated would not have the same effect. For instance, if the tube 6 were located farther down, the water for the top of the tank 1 would be converted into steam long before the zone of heated water extended down far enough to reach the control tube and cause the necessary operation of the thermostate 7 to alleviate the undesired condition.v Conversely, if the control tube were located farther up, the thermostat would have to be 1 be at steam temperature, while the Water below would be cold. Any disposition of the control tube ti below the medial position would require successively lower settings of the thermostat to eliminate excessive temperatures at the top. An obvious result would he that the temperature of the water Wouldhave to take perceptible drop before the thermostat would act to again start the heating operation. There is a lilielihood theta person drawing off water would get cold water, rather than hot water as desired.

llv'ith the control. tube 6 located in the medial-position, there will be an assurance of an ample quantity water in the tank 1 at a temperature of 1&5 degrees or thereabout.

will immediately 1 to act in the While the construction and arrangement of the improved liquid heater is that of a generally preferred form, obviously modifications and changes may be made without departing from the @spirit of the invention or the scope of the claims.

1. A heater comprising a tank adapted to contain a substance to be heated, an electrical heating unit to impart heat to said substance, a thermostat to control an electrical I circuit in which the unit is situated, and a confined volume of liquid in which said unit and thermostat are immersed, said volume of liquid being subject to a rapid increase in heat in the absence from the tank, of said substance to take the heat away, for an operation of the thermostat to open said circuit.

2. A heater comprising a heating unit, control means by which the heating effect of the unit is controlled so that it is rendered operative and inoperative, and a fluid containing said unit and from which heat is directly imparted to a surrounding medium to be heated, in a portion of which fluid the control means is immersed, depending upon an equalization of the temperature of said fluid portion and said medium for its action on the control means.

3. A heater comprising a heating unit, control means by which the heating eflect of the unit is controlled so that it'is rendered operative andinoperative, means containing a column of oil in which the heating unit is immersed, being subject to being heated and to impart heat to a medium surrounding said means, and a branch in which said control means is situated, being in communication with said oil containing means so that the control means is immersed in the oil.

4. A heater comprising a heating unit,

' control means by which the heating effect of the unit is controlled so that it is rendered operative and inoperative, a heater tube containing a column of oil in which the heating unit is immersed and which oil imparts heat to a liquid medium surrounding the tube, and acontrol tube in which the control means is situated, being in communication with the heater tube and containing some of the oil in which the control means isimmersed, but remaining relatively cool until the heat zone of said medium reaches the control tube so that an equalization of temperatures of the oil in said tube and the surrounding medium is established.

5. A heater comprising aheating unit, control means by which the heating effect of the unit is controlled so that it is rendered operative and inoperative, a heater tube containing a column of oil in which the heating unit is immersed and by which oil heat is imparted to a surrounding liquid medium, and a control tube containing the control means, being located medially of the heater tube and extending laterally therefrom, said control tube being in communication with the heater tube and containing some of the oil, which oil remains relatively cool, regardless of the heat of the oil column, until the zone of the heated medium reaches the control tube whereupon the temperature of the oil in the control tube and the surrounding medium rises together to a point at which the control means is set for operation.

6. A heater comprising a liquid storage tank, a heater tube suspended into the tank, a control tube in communication with a branch medially of the heater tube, an electrical heating unit situated in the heater tube, ,a thermostat situated in the control tube, anda volume of oil in the heater tube at a level above the orifice of the control tube, acting to disperse heat to a liquid medium when the tank is filled for an ultimate operation of the thermostat when the heated zone reaches the control tube, and acting to immediately heat the oil in the control tube for an immediate operation of the thermostat should'the'tank be devoid of liquid.

7. A heater comprising a heating unit, control means by which the heating unit is controlled so that it is rendered operative and inoperative, and means which at once transmits heat from said unit to a surrounding liquid medium, but of which a portion is dependent upon an increase in the temperature of said medium up to a determined point for the action of said control means to render the heating unitinoperative.

8. A heater comprising a tank, a heater tube suspended in the tank, containing a quantity of, oil and having a control tube communicating with the heater tube at a point below the oil level and extending to a point outside of the tank, a thermostat introduced into the control tube at the latter point, said thermostat having an associated electrical circuit, and an electrical heating unit embraced by the circuit being suspended within the heater tube and immersed in the oil. I

Signed at the city of Washington, in the BARNETT W. MACY.