US2303382A - Heater control - Google Patents

Description

Dec. 1, 1942. R. c. NEWHOUSE HEATER CONTROL Filed Feb. 28, 1940 Patented Dec. 1, 1942 (UNITED; ATE

PATENT OFFlCE- I nsarnn con'rnon Bay 0. Newlmuse, Wauwatosa, Wis. Application February 28 1940, Serial No. 321,233

. 'zcnim (Cl. ass-.20)

This invention relates to the .control of heat generating devices and more particularly to the manner of and means for controlling the fuel burning heat generating devices of hot water storage systems...

Hot water storage systems embodying a fuel burning heater generally include an automatic temperature responsive control means operable to increase the rateof heat generation whenever the temperature of the stored hot water decreases Still another object of this invention is to pro- -vide an. improved control means operable to increase the thermal emciency of intermittently operated fuel burning heaters.

, Another object of this invention is to provide an improved control means operable to decrease the frequency and to increasethe duration of the intervals of operation of intermittently opa predetermined amount. The known arrangey merits comprise a motor actuated fuel valve, a. thermostatic device positioned to be responsive to the water temperature at a point near the bottom of the storage tank and connections rendering said device operative to eifect an opening and closing movement of the valve whenever the temperature of the water at such point reaches predetermined minimum and maximum values respectively. In the-usual hot water storwhich is operable to heat the entire contents of age system the hot water withdrawn from the top portion of the storage tank is replaced by a commensurate quantity of cold water which enters the tank near the bottom thereof and con= tacts the said thermostatic device. Consequently,

, operation decreases since an increasing amount a of fuel is used in reheating the burner and the other associated heater parts which dissipate heat and become cool during the non-operating intervals. Moreover, the, gas 'or oil burners generally used in water heaters, which consist of a main burner to which the fuel supply is enti ly cut of! by the thermostatic device and a nstantly burning pilot or an electric ignition device to ignite the fuel issuing from the main burner when the said valve is opened,- invariably waste an appreciable amount of fuel during the ignition period. Furthermore-these burnersseldom operate eillciently until after the walls of the mixing and combustion chambers have become thoroughly heated.

- storage tank i, which includes the usual jacket 2* 'erated'fuel burning heaters.

A further object of this invention is to provide an improved-control means for hot water storage systems embodying a fuel burning heater the storage .tank, and to prevent the operation of the heater until a predetermined quantity of water has been withdrawn from the said tank.

The invention accordingly consists of the method of operation and of the various features of construction, combinations of elements and arrangements of parts as more particularly set forth in the appended claims, and in'the detailed description, in which:

Fig. 1 is a schematic illustration of a hot water storage tank and fuel burning heater arrangement embodying the invention; and

Fig. 2 is an enlarged view, partly in section, of I the fuel valve operator shown in Fig. 1.

Referring to Fig. 1 it is seenthat' the hot water filled with a fabric or other suitable material, is provided with a water heater arrangement comprising the fuel burning heater 3, a heat exchanger l. disposed within the heater 3, a. flue connection Ii adapted to be connected to a chimney for withdrawing the products offcombustion, and the pipes 6 and I which connect the interior of the tank in gravity. circulatory relation with the heat exchanger 4. The tank i, is provided with the usual cold water inlet and hot water outlet connections 8 and a respectively. The

heater 1 is provided with amain burner ii; to

which fuel is supplied through the pipe II, the

\ 'motor actuated valve l3, andthe pipe M. The

It is, therefore, an object of this invention to provide an improved method of operating fuel I an improved heater control means.

usual pilot or ignition device which operates to ignite the main burner whenever the valve I3 is opened has been omitted in the interests of simplicity.

Referring to Fig. 2, it is seen that the actuating means .for the valve it comprises a pair of axially spaced solenoids l6 and I1, and the axially movable core I! to which when the solenoid It is energized, the core i8 is moved upward and into engagement with the stationary. core II of the solenoid II, which is secured the stem I! of the valve It. The arrangement is such that de-energized and the valve I3 is in its closed positio energization of the solenoid l1 will not raise the core I8 and open the valve II. The solenoids may be mounted on the valve casing 22 by any suitable means, such as the bracket 23. t

The circuit for energizing the solenoid 18 comprises the wire 24, wire 26, the thermostatic switch 21, wirev 28, wire 29 and wire 8|. The wires 24 and 3| connect with a suitable source of electric power not shown. The circuit for energizing the solenoid l1 comprises wire- 24, thermostatic switch 32, wire 33, wire 34 and wire II. The thermostatic switches 21 and 32 operate to close and open the circuits in which they are included whenever the temperature of the heater point an appreciable distance above the thermostatic switch 32. In this connection it is preferable that the thermostatic switch 21 be so positioned that a predetermined and substantial portion of the contents of the storage tank must be at a temperature less than a predetermined value before the switch 21 closes. The shown position of the thermostatic switch 21 which permits. the withdrawal of apprdximately onethird of the contents of the storage tank before the burner is operated to increase the rate of heat generation, will be found satisfactory for most installations.

The operation of the previously described system, assuming that the storage tank is completely filled with heated liquid at .the desired temperature, is as follows: Under the'assumed conditions,

the thermostatic switches 21 and 32 are both open, and the fuel valve I3 is either closed or partially closed, but, as soon as a relatively small quantity of heated liquid is withdrawn from the connecting said first device and said second tank, the incoming unheated liquid will cause the thermostatic Switch to close, which energizes solenoid l1. However, energization of solenoid .l1 doesnot move the valve l3 toward its fully open position for the reasons previously de-' scribed-and small quantities of heated liquid can thereafter be withdrawn from time to 'time and without effecting an opening movement of the valve l3 and'a corresponding high rate of heat whereupon the valve I3 is moved toward its fully open position and the burner l l operated to increase orinitiate the rate of heat generation which operation continues until the liquid adjacent the bottom of the tank reaches a value operativeto again open the switch 32, The operation of the burner l I for a relatively short period is sufficient, unless heated liquid has been withdrawn in the meantime, to open the switch 21, but the opening of this switch will-not decrease the valve J3 is held open by solenoid H which remains energized until the switch 82 opens. Opening of the switch 32 decreases or terminates the generation of heat by the bumer II which again remains in this inoperative condition until the unheated liquid in the tank reaches the immediate vicinity of the thermostatic switch 21.

Consequently, it is seen that unless relatively large quantities of heated liquid are withdrawn at any one time, the heater only operates at infrequent intervals, and that the duration of heater operation is materially increased with respect to the prior art arrangements, which has resulted in an appreciable increase in the thermal efficiency of heated liquid storage systems embodying a fuel burning heater arrangement. The terms heated" and unheated as herein used are intended to mean that the temperature of the medium or substance to which the terms are applied is above and below a predetermined value. respectively. The invention is applicable to'the control of fuel burning heaters generally and although the invention has been disclosed as applied to a hot water storage system, and as embodying an electrical control system, it should be It is desired to claim and secure by Letters Patent:

l. A liquid heating arrangement comprising a heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater, a first temperature responsive deviceoperatively associated with said tank at a point near the bottom thereof, a second temperature responsive device operatively associated with said tank at a point a substantial distance above said first device, a regulative device controlling the fuel supply to said heater and including a first means operative when actuated to move said regulative device toward its maximum fuel supplying position and a second means operative when actuated to retain said-regulative device in the position to which it is movedby said'first means, means means so that the said second means is actuated only when the temperature of the liquid in proximity to said first device is at less than a predetermined value, and means connecting said second device and said first means so that the said first means is actuated only when the temperature of the liquid in proximity to said second device is at less than a predetermined value.

2. A liquid heating arrangement comprising a heated liquid storage tank haying connections for withdrawing heated liquid and for admitting.

liquid to be heated, a fuel burning liquid heater, a first temperature responsive device operatively associated with said tank at a point near the bottom thereof, a second temperature responsive device operatively associated with said tank at a point a substantial distance above said first device. a regulator controlling the supply of fuel to' said heater, and means for rendering said second device operative whenever the liquid in proximity thereto is at less than a predetermined temperature and independently of said first device to cause said regulator to be moved toward or terminate the rate of heat generation since 7 its maximum 'fuel supplying position, said first asoaaea tained in thefuel supplying position to which it has been moved by the operation of said second device.

3. A liquid heating arrangement comprising a heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater, a first temperature responsive device operatively associated with said tank at a point near the bottom thereof, a second temperature responsive device operatively associated with said tank at a point which is a substantial distance below the top thereof and which is 'a substantial distance above said first device, a regulator controlling the supply of fuel to said heater, and connections rendering said second device operative whenever the liquid in proximity thereto is at less than a predetermined temperature and independently of said first device to cause said regulator to be moved toward its maximum fuel supplying position, and said first device being operative whenever the liquid in proximity thereto is at less than a predetermined temperature to cause said regulator to be retained in the fuelsupplying posi-'- tion to which it has been moved by the operation of said second device.

4. A liquid heating arrangement comprising a heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater, a first temperature responsive device operatively associated with said tank at a point near the bottom thereof, a second temperature responsive device operatively associated with said tank at a point a substantial distance'abovesaid first. device, a regulator controlling the supply of fuel to said heater, and connections rendering said second device operative whenever the liquid in proximity thereto is at less than a predetermined temperature and independently of said first device to cause said regulator to be moved toward its maximum fuel supplying position, said first device being operative whenever the liqiud in proximity thereto is at less than a predetermined temperature to cause said regulator to be retained in the fuel supplying position to which it has been moved by the operation of said second device.

5.'A liquid heating arrangement. comprising a heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater, a first temperature responsive switch actuating device operatively associated with said tank at a point nearthe bottom thereof, a second temperature responsive switch actuating device operatively associated with said tank at a point a substantial distance above said first device. a regulator controlling the supply of fuel to saidheater,

and electrical connections rendering said second device operative whenever the liquid in proximity thereto is at less than a predetermined temperature and independently of said first device to cause said regulator to be moved toward itsmaximum fuel supplying position, and said first-device being operative whenever the liquid in proximity thereto is at less than'a predetermined temperature to cause said regulator to be retained in thefuel supplying position to which it has been moved by the operation of said second device.

6. A liquid heating arrangement comprising a v, heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater,

a first temperature responsive switch actuating device'operatively associated with said tank at a point near the bottom thereof, a second temperature responsive switch actuating device operatively associated with said tank at a point which is a substantial distance below the top thereof and which is a substantial distance'above said first device, a regulator controlling the supply of fuel to said heater, and electrical connections rendering said second device operativewhenever the liquid in proximity thereto is at less than a predetermined temperature and independently of said first 'device to cause said regulator to be moved toward its maximum fuel supplying position, and said first device being operative whenever the liquid in proximity thereto is at less than a predetermined temperature to cause said regulator to .be retained in the fuel supplying position to which it has been moved by the operation of said second device.

7. -A liquid heating arrangement comprising a heated liquid storage tank having connections for withdrawing heated liquid and for admitting liquid to be heated, a fuel burning liquid heater, a, first temperature responsive device operatively associated with said tank at a point near the bottom thereof, a second temperature responsive device operatively associated with said tank at a point a substantial distance above said first device, a regulator controlling the supply of fuel to said heater, a first means operative to move said regulator toward its maximum fuel supplying position, a second means operative to retain said regulator in the position to which it is moved by said first means, means connecting said first device and said second means so as to render said second means operative only when the liquid is proximity to said first device is at less than a predetermined temperature, and means connecting said second device and said first means so as to render said first means op-' erative only when the liquid in proximity to said second device is at less than'a predetermined temperature.

RAY C. NEWHOUSE.

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