US1522214A - Electric boiler - Google Patents

Description

Jan. 6, 1925.

BEST AVAILABLE COPY l v I 1,522,214 H. L. UNLANDI zmc'm'c BQILER Filed Nov. 22, 1925 Inventor:

Harry Luhlanol,

' HssAt-comy,

Patented Jan. 6, 1925.

BEST AVAILABLE COP.

, UNITED STATES PATENT OFFICE.

KARRY I1. UiNLAND, OF SCHENECTADY,"NEW YOBK, ASSIGNOB T GENERAL ELECTRIC COMPANY, A CORBQRATION OF NEW YORK.

. nmzc'rmc momma Application filed November 22, 1923. Serial No. 676,423.

limited thereto.

For certain applications, the condition is met with where a small amount of steam is required-continuously and where for brief intervals a comparatively large amount. is required. For example. in connection with steam turbines itmay be desirable to keep a turbo-gcnerntor set operatinp continuously at practically no load in order to have it warmed up and running ready to assume a load in case of some emergency. In such a (use it is ueccssarv, of course, to have available a supply of steam for, operating the turbine which supply is of suflicient volume to carry the emergency load, andthe object of my invention is to provide an electric boiler particularly adapted for use under these operating conditions.

1 For a consideration of what I believe to be novel in my invention. attention directed tothe accompanying description and the claims appended thereto.

In the drawing the figure is a, diagrammatic view of an-elcctric boiler embodying my invention. Y

Accordin to my invention, I provide an electric boiIer comprising a drum 1 which contains a supply of water 2, and a shell 3 directly adjacent the drum and containing the electric heating elements 4. In the present instance the electric heating elements 4 are in the form of electrodes car- 'ried by supporting conductors 5 which project through insulators 6 to the outside of the shell. Three electrodes are shown which adapt the'boiler for connection'to a source. of three-phase alternating current. The lower end of electrode shell 3 is connected to drum 1 by a number of openings 7 and also by a conduit 8 controlled by a valve 9 having an operating handle 10 lo cated outside of drum' 1 so that valve 9 may l be adjusted at any ,WhlCll may be driven in any suitable mantime. At 11 is a pump ner and which draws water from drum 1 through a conduit 12-and delivers it to shell 3 through a conduit 13. Conduit 13 has two-branches 14: and 15 each provided with a regulating valve 16. Byadjusting valves 16 and also valve 9 the rapidity of the circulation of the water from drum 1 to shell 3 may be regulated. The upper portion of drum 1 and shell 3 wluch are steamspaces are connected by conduits 17 and 18 to a.

conduit. 19 which conveys steam to the point of consumption. i

Arranged i conduit 19 is a pressure re ducing valve lo-which is set to effect a substantial reduction of pressure in the steam flowing through it so that itmaintams on its inlet side, that is in drum 1 and shell 3 a pressure substantially higher than is appliedto the point of consumption. for example, the steam turbine inlet. This means, therefore; that there is a substantial difference in pressure between the steam generated and that'applied'to the turbine inlet or-otherconsum tlon point. Valve 20 may be of any suita 1e structure. In the present instance, a known type is indicated, the amount which the valve is opened befng-- under the influence of the pressure on time discharge. side of the valve so as to maintain such pressure substantially constant, as is well understood. With such a .valve. when the pressureon the low pressure side decreases due to an increase in the demand for steam the valve is automatically opened further while when such pressure increases, the valve will be moved toward closed position. Inconduit 19 I provide also preferably, a non-return valve 21 which may be of any suitable structure and serves to-prevent flow from conduit 19 biick toward the boiler.v 22 indicates a conduit through which makekup water may be supplied to the boiler. Y p

In operatiompum 11 continuously circulates water from rum 1 through pipes 12 and l3to shell from whence rur back to drum 1 through openings-"7 an.

conduit 8', and the pump and valve 9 are so BEST AVAlLABLE COP\ depth to. which the electrodes are submerged, as is well understood, and the regnlation is made such that the electrodes will be submerged to such a depth as to genei'atesuilieicnt steam to supply the normal minimum requirements at the point of consumption .for example, iii.the case of a steam tur iine to keep the turbine operating idle, and in addition charge and keep charged uith heat the water in drum l. Drum 1 is in communication with the steam space in electrode shell 3 through pipes 17 and 18 so that the pressure in drum 1 is the same as that of the steam being generated,

' and the circulation of the water from drum 1 to the electrode shell 3 maintained suiliciently rapid so that the water in drum 1 will he maintained at substantially the same temperature as that-in shell 3, i. e., at the temperature corresponding to the temperature of saturated steam at the pressure' in the boiler.

As stated above, the electric boiler-generates sufiicient steam to supply the "normal requirements tothe point of consumption. In case of a sudden large demand, the pressure on the discharge side of the reducing valve 20 will decrease which results in a further opening of valve 20 and a more rapid flow of steam through it and hence a reduc- 1 tion of the pressure in drum 1 and shell 3.

heat storage drum 1 may he made such as to meet the operating conditions met-with in any particular instance. The arrangement finds especial u tilityhowever, where the normal requirements are comparatively small as com ared to the occasional or emergency demand, and the emergency demand Occurs but seldom, for under these circum-- stances the electric boiler need be only large enough to meet the normal demand-for steam and to recharge the heat storage drum 1 within a specified time.

' In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

, \Vhat I claim as new anddesire to secure by Letters Patent of the United States, is,-

1. In combination, an electric boiler comprising a shell, electric heating elements in the shell and a heat storage drum in direct communication with the shell, means for circulating liquid from the drum to the shell,

a discharge conduit which leads to apoint of consumption, and said conduit. g, 2. In combinatlon, an electric boiler com- ,prising a shell of smaller capacity and a heat storage drum of larger capacity, electrodes in said shell, means for circulating liquidfrom the drum to the shell and back to the drum, means fol-regulating the circulation, a discharge. conduit in communication with both the shell and lucing valve in said conduit.

' In witness whereof, I have hereunto set my hand this 21st day of November, 1923.

, HARRY L; UNLAND.

a reducing valve indrum, and a re-

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