US2529688A

US2529688A - Electric fluid heater

Info

Publication number: US2529688A
Application number: US744145A
Authority: US
Inventors: Edward L Grupp
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-04-26
Filing date: 1947-04-26
Publication date: 1950-11-14
Anticipated expiration: 1967-11-14

Description

Nov. 14, 1950 E. l.. GRUPP 2,529,688

ELECTRIC FLUID HEATER Filed April 26, 1947 2 Sheet's-Sheet l mmmmm lll.,

.nl vtt. m

SYN Il.

INVENTOR.

Nov. 14, 195o E. L. @UPP 2,529,688

ELECTRIC FLUID HEATER Filed April 26, 1947 2 Sheets-Sheet 2 d N l 1 www Patented Nov. 14, 1950 UNITED STATES PATENT OFFICE ELECTRIC FLUID HEATER -Edward L. Grupp, Glendale, Calif.

Application April 26,1947, Serial N o. 744,145

This invention relates to an electric fluidheater, and more particularly but not necessarily to an electric water heater.

All of the electrical water heaters known to me are objectionable in that the electrical groundy loss is greater than that permitted by the underwriters in some districts. Also they do not provide for heating water of diierent conductive characteristics. Particularly, heaters which use the water as resistance to conduct the current between the electrodes and heat the water by subjecting it to the electrolytic action of the current do not provide means for varyingthe effective area of the Yelectrodes to compensate for the different mineral content of water to be heated.

It is therefore a primary object of this invention to provide an electric water heater that will overcome the above diculties.

Another object is to provide an electricwater heater wherein the casing containing the heating elements and other parts is insulated in such a manner as to reduce the electrical ground loss from the unit to a minimum and thereby lrender the heater safe for usefin any location where such a heater is desired.

Another `object is to provide in a heater having the above characteristics novel electrodes adjustable for varying the distance between the electrodes and adjustable for varying the effective area of the. electrodes in order to obtain the proper lelectrolytic action on Vwaters of different.

mineral contents.

-A further object is to provide a heater ofnovel construction and arrangement of parts that will be durable, eftlcient in operation and comparatively cheap to manufacture.

A still further object is to provide a heater in which the heating element is energized in response to the supply of water to the Vheater and deenergized when the supply of water to the heater is stopped.

'I'he above and other objects will'be made apparent throughout the further description of the invention when Vtaken in connection with the accompanying drawings, wherein like reference characters refer to like parts. It is to be distinctly understood that the drawings are not a denition of the invention but merely illustrate one form `by means of which the invention may be eifectuated.

In the drawings:

Fig. 1 -is a front elevational view having the cover removed, partly in section, and with certain parts broken away in order to disclose details of the invention.

`8 Claims. A(Cl. 219-40) Fig. 2 is a sectionalview taken along the line II-II 0f Fig. l.

Fig. 3 is a sectional view taken along the lineembodied in the invention.

Referring to the-drawings, thefpresent heater may include a housing or casing, represented in its entirety-by IQ. The housing provides a heating* unit compartment I-I, a switch compartment I2, and a cylinder I3.

side I1, and the walls I8 ofthe cylinder I3 may be cast, molded, or otherwise formed to providean integral structure. ing may consistof a cover plate 2| for the heating unit compartment I-I and a cover plate 22 for the Lswitch compartment I2. terminates at its outer end in an inwardly eX- tending flange 23, the latter forming .theother end of the-housingvlll.

One of the important featureSo'f the invention is the provision of suitable insulation of the housing in order to reduce the electrical ground loss of the vheating unit to a minimum. I have found by experiment that effective insulation for this purpose may be obtained by constructingV the housing-of aluminum or brass and providing the housing with a 4high dielectric coating of phenolic resinoid. A suitable insulating compound for this purpose consisting of a phenolic resinoid is known to the ytrade as Heresite I Vhave also discovered that a coating of phenolic resinoid of one mil thickness When properly applied to aluminum or brass is effective for properly insulating a voltage as vhigh as 18'00 volts. The

housing is sprayed both internallyand externally:

with phenolic resinoid to provide a coating of the desired thickness, after which time the coats' ing is baked. The baking may be at 220 F; for

a period of twenty-four hours, or at 500 F. for ten minutes. Phenolic resinoidcoating has high thermal shock resistance and is tasteless and odorless.

The compartments :IIY and i2 of the housing are separated by a vertical transverse partition' 26. The partition 26 is integral with the back I4, top I5, and bottom I of the housing I0 and is provided with a phenolic coating the same ias above described. The interior ofthe heating unit compartment II is further lined .with an Vinsulation strip 25 of phenolic material having avthickness of T36 of an inch. The heating unit consists Inthe construction of the housing IIJ, the back I4, top I5, bottom I6, onef The front of the hous- The cover plate -22 of a pair of plate-

like carbon electrodes

21 and 28 spaced apart by spacer members 3l, a pair of

contact plates

32 and 33 adapted to lie flat against the opposing faces of

electrodes

21 and 28, respectively, a pair of curved or arcuate shaped

spring members

35 and 36, and a split, ceramic casing composed of two

parts

31 and 38. The arcuate shaped spring member 35 is disposed between casing part 31 and contact plate 32, while spring member 36 is disposed between casing member 38 and contact plate 33. It can now be understood that when the

ceramic casing parts

31 and 38 are urged toward one another by the cover 2|, the

spring members

35 and 36 will be compressed and urge their respective

adjacent contact plates

32 and 33 into contact withthe respective opposing faces of

electrodes

21 and 28, the

electrodes

21 and 26 being held in spaced relation by spacer members 3 I. The spacer members 3l are made of suitable insulating material and arepreferably roundgand present flat, annular faces on each of their sides, one'of their sides being provided with a centrally disposed lug or projection 42, adapted to engage corresponding openings 43 provided ,in the'inner face of one of the electrodes. Spacer members 3I of different thickness may be provided for adjusting the spacing between the electrodes and the required number of spacer members may be inserted between the electrodes to provide the desired effective area of the electrodes. By the use of spacer members of different thickness to adjust the spacing between the electrodes, and by increasing or decreasing the eective area of the electrode by varying the number of spacer members between the electrodes, the heater may be easily and quickly converted for proper heating of waters of diiferent mineral content.

The contact plate 32 is slit at 45 to form a terminal strip 46. The terminal strip 46 terminates in an inwardly extending tab 41 having an opening therein for receiving one end of a terminal 48 and is xed thereto by any suitable means, such as the threaded means shown at 49. The terminal 48 extends through an opening 46 in the partition'26 and is suitably insulated therefrom by a porcelain cover 5I. `The terminal 43 and cover 5I are preferably formed integral with each other anda threaded means 52 may also be formed integral with cover 5I in order to make a fluid-tight unit. The opening 46 may be internally threaded and counterbored to form an annular beveled shoulder to cooperate With the beveled inner end of the threaded means 52 and a copper washer inserted therebetween as shown at 54 to insure a water-tight connection.

The contact plate 33 is slit adjacent its top at 56 to form a terminal strip 51. The terminal strip 51 terminates in an inwardly extending tab 58 having an opening 59 therein for receiving one end of a terminal 6I.- The terminal 6I' is mounted through an opening in the partition 26, insulated therefrom, and forming a Watertight connection therewith in the same manner as that described in connection with terminal 48. In order to provide space Within the heating unit compartment Ii for the tab 41, terminal 48 and their threaded connecting means 49, the part 31 of the ceramic casing, spring member 35 and electrode 21 are recessed, as shown at 62,. Space is likewise provided within the compartment II for tab 58, terminal 6I and their associated threaded connecting means 49 by recesses in ceramic casing part 38, spring member 36 and electrode 28, as shown at 63.

of cylinderA i3..

The ends of terminals 48 and 6I within the switch compartment are electrically connected to a source of current by

conductors

64 and 65 respectively. The conductors enter the switch compartment by Way of a conduit 66 extending into an opening 61 provided in the top I5 of the housing I9. The end of the conduit may be rigidly fixed to the top I5 by means of the threaded connection 68. Interposed within the electrical circuit, comprising the '

conductors

64 and 65, is a switch or circuit breaker 69 having a switch arm 16 for actuating the switch in the `usual manner.

It will be noted from Figs. 2 and 4 that the f present device diiTers from prior constructions in three principal characteristics. First, the

spring members

35 and 36

contact plates

32 and 33 and

electrodes

21 and 28 are spring-held within the

casings

31 and 33 in what may be termed floating therewithin. This `permits expansion and contraction of the

springs

35 and 36 and

contact plates

32 and 33 without exerting undue .stress on the electrodes ,21 and `28 and thereby prevents the usual Vcracking and distorting of the latter. Second, the positioning of the

contact plates

32 and 33 between their respective springs and electrodes protects

electrodes

21 and 23 from friction due to relative movement of the

Springs

35 and 36, thereby greatly lengthening the life of the

electrodes

21 and 28. Third, the particular` fabrication of the heating unit Whereby spacer members of a selected area and thickness may be employed in such numbers as may be required for varying the distance between the electrodes for varying the effective area of said electrodes. Moreover, the present heating unit may be readily disassembled for inspection, replacement of any one element or repair, and quickly and readily reassembled into a compact, effective unit.

In the present invention it is desired to actuate the switch f or energizing the heating unit in response to the water supplied to the heating unit and to deenergize the heating unit when the supply of water is cut off from the heating unit. To this end, water is supplied to the unit by way of an inlet pipe 1I connected to the outer'end threaded nipple 12, the latter Yhaving -an internally threaded bore13, for receiving the threaded i The cylinder AI3 is connected end of pipe 1I. with the heating compartment I I by Way of a slot or elongated passageway 14 provided througl'ry the topof` the wall ofthe cylinder I3. For actuating the switch 69 to energize or deenergize the,

heating unit in response to demand for hot water from the heating unit, a piston'15 is provided within the cylinder bore i3. v The piston 15 is biased by a spring 16 toward its outermost posi-v tion in the cylinder, at which position its outer,y

face rests against theinner face of nipple 12. The piston 15 is preferably of the full-floating type and a spring-retaining cap 11l is iplaced; against the inner face of the piston 15 for engaging the outer end of coil spring16. 'IheotherI end of coil spring 16 engages the inner closed end 18 of the cylinder I3; The closed end 18 ofv threaded end of a switch-actuating rod 19, as shown at 80. The rod 19'y extends axially through l the cylinder I3, packing gland 8I,provided in the The outerend'of cylinder I3 is internally threadedffor receiving 'an externallyv rearvend 18 of cylinder I3, into the switch compartment I2, and terminates in a guide 82 carried by a bracket 83 iixed to the back Mvof the housing I by any suitable means,such asscrews 84. A portion of rod 19 within theswitch compartment and immediately below the switch arm is threaded to .receive two adjusting nuts 85 spaced apart. Between the nutssthere is positioned on the .shaft 19 a member 86 formed to provide a pair of spaced,

upstanding arms

81 and 88 between which the end of switch arm 10 extends.

It can now be understood that when water is supplied to the cylinder i3 by way of intake pipe.

1I, the force of the water will urge the piston against the tension of the spring 16 inwardly suiliciently to permit the passage of water from the cylinder I3 through the passageway 1.4 into the heating unit. Since piston 15 is appreciably shorter than passageway 14, water pressures on opposite sides of the piston readily balance each other, and the piston quickly responds to drop in pressure in chamber II when faucets in line 89 are opened.

As the piston is moved inwardly, the rod 19 will also move accordingly and cause the member 81 to move the switch arm 10 into close position and energize the heating unit. The heated water passes out the top of the heater by way of outlet pipe 89 connected with the top of the housing I 8, as shown at 90. Upon cutting oif the water supply to the cylinder I3, the spring 16 will urge the spring-retaining cap 11 and piston 15 to their outermost positions and since the rod 19 is -xed to the cap 11, the rod will be moved to the right and cause member 88. to move the switch arm 18 to break the circuit and deenergize the heating'unit. It is to be understood in connection with the above explanation, that a faucet or faucets may be located in line 89 and water is continually present within the heater. When a faucet in line 89 is opened, pressure within the heater (and within bore I3) is reduced,.causing line pressurein supply pipe 1I to move piston 15 and supply a stream of water to the heater.

A tubular stop member 9I may be carried by the inner face of the gland member 8| for limiting the inner travel of the spring cap and piston. Also a roller support or guide 92 may be provided in the switch compartment for contact with the bottom of member 86 for assisting in the support and guiding of the rod 19.

In order to equalize and compensate for the differential pressures between the interior of the cylinder and the heating unit when 'piston 15 reaches closed position, there is provided a bypass 93 adjacent the inner end of nipple 12. An adjusting screw 94 may be provided in the housing and connect the by-pass 93 for adjusting the same. The rear end of the piston 15 maybe beveled or provided vwith recesses for connecting the interior of the intake pipe 1I with the bypass 93 when the piston 'I5 is in closed position.

In the bottom of the wall of the cylinder I3 there is provided a drain plug 95 for draining the heating unit and cylinder during cold weather when the heater is not in use. Also there is provided a trap 96 in the bottom of the switch compartment for catching any leak-age from the gland 8l, the trap 99 being provided with a plug 91 for draining the trap.

Accordingly there is provided an electric heater for water or other fluids that is so constructed and insulated as to insure a minimum electric ground loss, which can. befadjustedfor the proper.

inexpensive to operate and comparatively cheap.

to manufacture.

While only one form of the inventionhas been illustrated and described, itwill nowv be apparent. to those skilledinthe art. that certain changes, additions, omissions, and substitutions may be made in the exemplary form shown Withoutdeparting from the spirit andscope of the invention as deiined by the appended claims.

I claim: Y

1. A fluid heater including: a.housing;A a partition in said housing forming two compartments; a cylinder in said housing; an electricV switch in one of said compartments; a heating unit in the other. of said compartments, said heating unit comprising a pair of electrodes;

means for biasing said electrodes toward one another; and means for retaining said electrodes at a desired distance apart, said biasing means being supported in floating relation to the rst named compartment; an electric conductor connecting said switch and said heating unit; means for connecting a source of current tosaid switch; a piston in said cylinder; a fluid inlet and a fluid outlet connected with said heating unit compartment; means actuated by said piston in response to uid pressurein said inlet for actuating said switch, and an adjustable .portv connecting said inlet with said other compartment for equalizing the pressure therebetween.

2. An electrically energized instantaneous water heater including: an outer metallic housing; a compartment in said housing; an inlet bore in the housing near one end of said compartment; a port connecting said bore and compartment; an outlet port in the housing in communication with the other end of the compartment; a pair of opposing, dielectric casings in the compartment; an electrode plate in each casing; spring means between each casing and its electrode urging vsaid electrodes toward each other; andv removable spacer means between said electrodes and attached thereto, the said electrode plates and spring means being supported in iioating relation with said casings.

3. An electrically energized instantaneoustype water heater, comprising: an outer metallic relatively at housing provided with a transverse partition dividing said housing into a switch compartment and a heating compartment, a piston bore in the bottom of the housing, an inlet port into the end of the piston bore, a lateral passageway from the piston bore in communication with one side of the heating compartment, an outlet port in the top of the housing opposing the lateral passageway, a spring-biased piston in the bore, said piston normally closing the inlet port, and a pair of flat electrodes in spaced relation in the heating compartment and between said lateral passageway and outlet port; at least one of said electrodes being provided with a series of recesses, and removable spacer means arranged to be held in said recesses of one electrode and contact the opposite electrode to limit the eiective surface area of said electrodes.

4. In a iluid heater the combination of: a housing including a back, top, bottom and sides and an open front; a removable closure for the front of the housing to form a compartment therein; a iluid inlet into the bottom of the liousing and a uid outlet in the top of the housing aaaess 1. andin communication with the compartment; a ceramic casing Within the compartment; a pair of imperforate electrodes in said casing; spring means biasing the electrodes towards each other and means for maintaining the electrodes in a predetermined, spaced, relation comprising a plurality of spacer members carried by one of said electrodes, said spacer members being removable to Vary the eiectve surface "area of the electrodes. Y

5. In a fluid heater the combination of: a housing provided with a transverse partition forming two compartments in said housing; a switch means positioned in one of said compartments; a cylinder formed in the wall of the housing below the second compartment; a fluid inlet into one end of the cylinder; a port communicating the side of the cylinder with the second compartment; a piston in the cylinder, said piston being spring biased to normally close the fluid inlet; an adjustable pressure equalizing passageway between the second compartment and said cylinder, normally closed by said piston, said passageway communicating with the cylinder between the fluid inlet and port; a heating unit in the second compartment and connected to the switch means and means actuated by the piston in response to fluid pressure in the inlet for actuating the switch.

6. A fluid heater of the character stated in claim 5 wherein the heating unit comprises a pair of imperforate electrodes, spring means biasing the electrodes towards each other; and means for maintaining the electrodes in predetermined, spaced relation comprising a plurality of spacer members carried by one of said electrodes and in contact with the other electrode.

7. An electrically energized, instantaneous, water heater comprising: an outer metallic housing Vprovided with a partition dividing said housing into two compartments; a switch in one of said compartments; an inlet bore in the housing near one end of the second compartment; a port connecting said bore and compartment; an

outlet port in the housing in communication with the other end of said compartment; a pair of opposing dielectric casings in the compartment; an electrode plate in each casing, said electrode plates being in parallel, opposing relation; spring means between each casing and its electrode urging said electrodes towards each other; and removable spacer means between said electrodes and attached thereto, the said electrodes and spring means being supported in.

floating relation with respect to said casings; and piston means in operative relation to said port arranged to actuate the switch in response to uid pressure in the inlet bore.

8. In an electrically energized, fluid heater the provision of: a pair of flat, imperforate electrodes in parallel relation and selective means for variably spacing said electrodes at a predetermined distance, said means including a series of recesses in one of the opposing faces of said electrodes and spacer members extending thereinto and contacting the opposing electrode face, said spacer members being removable to vary the effective surface area of the electrodes.

EDWARD L. GRUPP.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 754,451 Hill Mar. 15, 1904 1,689,521 Dominguez Oct. 30, 1928 1,916,064 Mortensen June 27, 1933 1,941,584 Sexton Jan. 2, 1994 1,990,790 Lenz Feb. 12, 1935 2,257,841 Elam Oct. 7, 1941 2,306,921 wncox Dec. 29, 1942 2,312,677 Shrum Mar. 2, 1943 2,325,722 Walther Aug. 3, 1943 2,428,445 Wicks Oct. 7, 1947 2,429,112 Warren Oct. 14, 1947