US1932447A - Electric steam boiler - Google Patents

Description

.pa 31, 1933. s. CAPLAN ELECTRIC STEAM BOILER FiledApril 14, 1932.

INVENTOR Patented Oct. 31, 1933' UNITED- STATESl PATENT. OFFICE 1,932,441 ELEc'riuc STEAM nonna samuel Caplan, Detroit, Mich. Application April 14, 1932. Serial No. 605,275 s cwms. (ci. zic-as) The present invention pertains toa novel electric steam boiler designed particularly for the generation of steam in connection with garment pressing machines, hat blocking machines, and the like.

In such machines, steam is used in comparatively small quantities and at a comparatively low pressure, and it is further desirable to generate steam in a very short time. The object of the present invention is to provide a machine having these characteristics and further equipped with eiective regulating and safety devices.

One of the characteristics o! the invention is the provision of a boiler shell or liner having an ovoid cross section with its major transverse axis standing vertically. Thus, the space in the lower part of the boiler is restricted as compared with the space in the upper part andaccommodates a comparatively small quantity o! water. An electrical heating element is mounted in the lower part and is so constructed as togenerate steam rapidly, while the comparatively large' steam space within the liner maintains the steam at the low pressure suitable for the work described above. This pressure varies from twelve to fteen pounds.

The boiler is further equipped with a iloatcontrolled water inlet, but is further provided with another safety device adapted to open the circuit of the electrical heating element in case the water should drop below a safe level. This device prevents burning out of the heating element when there is insuillcient water in the boiler to maintain the element at an undestructive temperature. The device consists of a thermostatic switch mounted close to, or adjacent to, or directly above or in contact with the heating element, and partly or wholly immersed in the water while the latter is at a nonnal level, with said switch in circuit with'the heating element. The switch is adapted to open when overheated and does so when the water drops below a safe level and thus exposes the switch to radiated heat or convection currents from the heating element whereby the current is cut ofi'. from the heating element.

The invention is fully disclosed by way oif example in the following description and in the accompanying drawing, in which- Figure 1 is a longitudinal section of the boiler, showing certain parts thereof in elevation;

Fig. 2 is a front elevation, with the iront insulation section removed:

Fig. 3 is a section on the line 3-3 oi Figure 1;

Fig. 4 is a longitudinal section of the thermostatic switch; and

Fig. 5 is a detail vertical section showing the fusible plug in the face of the boiler.

Reference to these views will now be made by use of like characters which are employed to designatev corresponding parts throughout.

In Figure l the boiler is illustrated as comprising a shell or liner l enclosed in insulating material 2 in the usual manner. The insulating 65 Jacket embodiesa removable face section 2 for enabling access to the face of the liner. The liner, however, is of ovoid cross section, as shown in Figure 3, having its major transverse axis vertical and its smaller portion downward. With the normal water level extending to approximately one-third of the major transverse axis, this construction provides a water space which is of considerably less volume than the steam space. This steam space limits the steam pressure to twelve to fifteen pounds which is the desirable pressure for the work for which the boiler is intended, namely, in connection with garment pressing machines, hat blocking machines and the like.

From the upper part of the boiler extend one or more steam outlet pipes 3 and 4, a pressure gauge 5 and a safety valve 6. To the rear end of the boiler is connected a water level gauge of usual construction. A drain pipe 8 extends from 85 the bottom of the boiler as shown in Figure 1.

An electrical heating element 9 is mounted in the lower part or restricted water space of the liner, as shown in Figures 1 and 3, and has at its forward end a screw plug 10 seated in the re- 90 movable face plate 1 of the boiler,.or any other appropriate attaching means such as a flange and bolts. The element is spaced slightly from the f bottom of the liner and is of such dimensions with respect to the volume of the normal water space as to generate steam rapidly. A water inlet pipe 1l extends into the face plate 1' of the boiler and is equipped with a valve casing 12. The casing has a valve pin 13 attached to a lever 14 which in turn is pivoted to the casing as at 15. An arm. 16 extends from the free end of the lever 14 and carries a float 17 which is adapted to follow the level of the water in the liner. The arrangement of parts is such that the float opens the water inlet valve on reaching a predetermined low level and closes the valve on reaching a predetermined high level.

In order to protect the heating element from being destroyed by overheating in case oi failure of the safety valve 6 or the float-controlled water 11o a fusib built to 4open the switch 28 at twelve pounds and inlet, a tbermostatic valve face plate 1' of the boiler asumainths ma opened and current ilow to the heating element.

'Ihe thermostatic switch, by being n partly or wholly immersed in water, is maintained at a temperature which does not ypermit o i thereof. However, if the water level should drop because of any cause whatsoever, such as failure of water supply, or it the temperature within the boiler should become excessive for any other reason, the thermostatic valve will open and thereby cut oil? the supplv of current to the heating element 9.

The face of the boiler is further equipped with shown in Figures 2 and 5, which melts on attainment of excessive pressure in the boiler and thereby relieves the pressure therein.

A pressure regulator 26 is connected to the steam space in the boiler by a pipe 27 and operates an electric switch 28 connected into the circuit 21 ahead of the relay 22. The switch is normally closed but opens on attainment of excessive pressure in the boiler, thereby disconnecting the heating element 9. The regulator is close it at ten pounds, so that an average pressure of eleven pounds is maintained.

Although a specific tion has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention, as indicated by the appended claims.

What I claim is:-

l. A boiler for rapid generation of steam, having a liner of substantially ovoid cross section and having its major transverse axis s vertically and its smaller portion downward, an electrical heating element in the bottom of said liner, an insulating jacket enclosing said liner, and a thermostatic switch in said liner and adjacent said element, said switch being in circuit with said element and adapted to open by exces- 2. A boiler for rapid generation of steam comprising a liner, an electrical heating element in the bottom thereof, an insulating jacket enclosembodiment of the inven- 3. Aboilerforrapid generation ofsteameomaliner electrical level falls, and a neat-controlled water inlet to said liner.

4. A boiler for rapid generation of steam, having a liner of substantially ovoid cross section oat for repair or inspection.

6. A relatively smallboiler for the generation small amount of steam, having a an electrical heating element immersed in the water space thereof, a float-controlled water inlet valve, said electrical heating element and water inlet valve being removably fastened to and water inlet valve, thermal insulation eiliciency by covering these parts, with a thickness of insulating material substantially equivalent to that used upon the other surfaces of the liner.

SAMUEL CAPLAN.

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