US1927023A - Steam generator - Google Patents

Description

G. L. COLEHE SeptC 19, 1933.,

Filed Sept. 15, 1931 4 Sheets-Sheet l lNV Us @C 53eme 1....... ATTORNEY Sept. 19, 1933s G L, 30; 555 1,927,623

STEAM GENERATOR Filed Sepi. l5, 1931 4 Sheets-Sheet 2 INVENTOR ATTORNEY.

G. l... COLBIE STEAM GENERATOR Sept. 19. 1933.

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INVENT'OR G05 [ca/fe ATTORNEY Patented Sept. 19, 1933 PATENT OFFICE STEAM GENERATOR Gus L. Colbie, Brooklyn, N. Y., assignor tok Hudson Electrical Heating Corporation, New York, N. Y., a corporation of New York Application September 15, 1931 Serial No. 562,932

Claims.

My invention relates generally to electrically heated steamgeneratorsA and more particularly presents certain improvements in the multiple unit type of such generators that is those comprising a multiplicity of generator units joined together to forma boiler of any considerable capacity.

One main object of the invention is to provide a pluralityv ofr boiler casings or unit cells, each 10. one of which is equipped with a. plurality of electrical heating elements and adapted to function either as an individual steam generator unit or .as one. oi a number of units which may be grouped together and joined by steam and water tight 15. connections to form a multiple unit generator of any desired capacity.

The'. latter feature is of major importance since the multiple unit structure is particularly adapted for use in conned spaces, of various shapes, such as are often found in the cabs of electric locomotives where my invention can be used to great advantage in producing steam for the heating system of railway cars drawn by an electric locomotive.

Further objects are to provide a new and novel method of supporting'the heating tubes to provide for expansion due to high temperature, and to provide a novel form of heating element that is rugged, durable, efcient and easily installed.

- Another feature of value is the joining of steam and water manifolds directly to the casings, thus eliminating the usual'steamand water headers.

Other features will appear to those skilled in the art on examination of the following specication. and drawings, in which,

Figure l is a plan view of a typical set-up of a multipleiunit steam generator embodying one form of my invention with a manifold joined to the steam outlet portions vof said unit.

Figure 2 is a side elevation of the construction shown in Figure 1, looking in the direction of arrow 2 in said latter figure.

Figure 3 is a front elevation of the construction shown in the direction of arrow 3 in Figure 1, with one cylinder and parts of the manifolds shown in section.

Figure 1i' is an enlarged'vertical section through one. cell. unit, showing one electrical heating element in section and another partly in section, also showingportionsof two adjoining cylinders,

Figure 5 is a crossv sectiontaken on the line 5,-5 of- Figure 3.

By the arrangement shown I construct cylindrical casings for the cells of drawn seamless tubing which are open at their upper ends and are adapted to be joined to other like cells to form a complete. boiler of any desired capacity.

Within each cellyunit there is placed a plurality of electrical heating elements of the cartridge type which are suspended from a head forming a. closure for the open end of each cell or casing. Each cartridge isf adapted to be easily withdrawn for inspection and the electrical resistors forming part of the heating elements are readily removable from within an envelope forming the outer wall of the cartridge. With this form of steam generator, steam is rapidly generated, and because of the intense heat which is generated in each heating. element, the cartridge is so mounted as to permit longitudinal expansion oi the said cartridge enevelope.

In. this form of steam generator, it is not necessaryv to bring the entire quantity of water in the boiler to a. steamingv temperature, since 7d in operationv it has been found that the water entering. at the bottom of the cell, flows upward as a column, and is gradually heated in its upward. passage until it reaches the top surface or water level. 8O

Any conventional type of feed water, regulator and pump may be used as. a means for maintaining a constant water level within the cell casings.

Throughout the drawings, likereference char- SD acters indicate like parts.

In Figure 4, a complete assembly is shown of one of thel generator units upon which a large portion of the following description may be read.

Each unit comprises a vertically disposed cylindrical cell 10 which is made of drawn seamless tubing closed at its lower end. A head 12 is inserted within the open top portion of this cell and is secured' thereto by any suitable means such as welding as indicated at 14. Water inlet 90 openings 16 are provided at the lower end of each cell and steam outlet openings 19 at the upper end thereof.

A plurality of electrical heating elements 1S are inserted in openings 2O provided in the head 12 of the cell and are properly secured thereto to form a steam. tight joint, Each electrical heating element comprises. an outer envelope 22, the lower end of which is closed, and into which is inserted the electrical heating assembly 24. An outwardly flared flange 26 around the upper open end of each envelope 22 is seated against a metallic gasket 28, which gasket rests upon a shoulder 30 within each of the openings 20 in the cell head 12'. An externally screw threaded collar 32 having a central recess 34 is screwed into a threaded opening 36 and is brought into clamping engagement with the flange 26.

A guide bracket 42, secured to the bottom of each cell 10, has openings 40, each one of which is adapted to receive a lug 38 projecting below the bottom of each envelope 22. By this arrangement the envelopes are permitted to expand or contract longitudinally in accordance with the temperature changes.

The electrical heating assembly 24 comprises a continuous strand of resistance wire 44, of large cross section, which is placed through spacer discs 46 of insulating material, to provide several vertically disposed lengths in a fixed, spaced relation, one with another.

Two halves of a resistor unit casing 48, having internal circumferential ribs 50 or the like, are formed or placed around the discs 46, said discs being confined between the ribs 50. After assembling, the halves of casing 48 may be welded at separate points along the joints as indicated at 52 to hold them together. Two rings 54-54 are placed around the casing at the top and preferably are welded thereto, leaving a space between, to accommodate a split insulating collar 56. Since the two halves of the casing 48 are slightly separated, as indicated in Figures 4 and 5, open spaces will be left between, through which radiated heat can flow from the resistor 44 to the inner surface of the envelope 22; thence by conduction the heat will pass to the water or steam on the other side of such wall. Additional openings 49 may be provided in the resistor unit casing 48 for this same purpose.

Within the lower end of the envelope 22 of the heating cartridge 18 is a centering block 58 of insulating material, having areduced neck 60 adapted to fit within the lower end of the resistor unit casing 48, to maintain same in a fixed spaced relation to said envelope 22. A space is left between the bottom of the casing 48 and a shoulder 62 on the centering block 58 to allow for longitudinal expansion of the said casing 48 relative to envelope 22 when they expand unequally under temperature variation.

After the electrical resistor 44 and its supporting discs 46 and two part resistor unit casing 48 are assembled for insertion within the envelope 22, as previously described, two halves of the split insulating collar 56 are placed around the upper portion of said casing 48, between the rings 54-54 and the whole is then inserted in the envelope 22. The lower end of the casing 48 is placed over the neck 60 of the insulating block 58, and the split collar 56 is fitted into the recess 34, in the threaded collar 32. The top of the said split collar 56 projects slightly above the top of the threaded collar 32. To retain this assembly within the envelope 22 and hold the interior parts of the heating cartridge 18 together, an internally threaded annular cap 64 is screwed onto the projecting portion of the threaded collar 32, said cap being provided with an inwardly extending flange 66, which is adapted to be brought into contact with the upper surface of the projecting portion of the split insulating collar 56.

Terminals are provided for the ends of the resistance wire 44, which comprises lugs 68, adapted to be secured to the ends of the resistor wire 44, by welding or any other suitable way, said lugs having threaded shanks which project up through an insulating cap 72 having a reduced portion 73 adapted to fit into the upper end of the resistor casing 48. Straps or any other form of connection 74, may be used to connect the units together electrically, the straps being placed over the ends of shanks '70 and secured thereon by nuts 76. In Figure 1 the resistor elements in each group of three cells are shown connected in series but these connections may be varied to suit any condition, and switches may be added to control any one or number of heating units.

The annular threaded collar 32 and its contained insulating filler elements, the split ring 56 and cap 72 together form a removable closure for the open end of the envelope 22, and also serve as means for supporting the upper end of the electrical heating assembly including resistor 44, spacing discs 46 and casing 48.

It will be observed from the foregoing description of the standardized heating cartridge that an interchangeable unit has been developed which can be inserted in any generator or boiler constructed according to this invention, or can be transferred from one to another portion of any such boiler. It will also be observed that the electrical heating assembly of resistor, resistor supports and the closure carrying these elements, form a standardized unit which can be used with any cartridge envelope 22.

Each casing 10, and set of heating cartridges 18 therein contained, constitute a complete steam generator which can be used by itself when equipped with the proper feed water and steam pipe connection; or any desired number of such generator sections can be joined together by connecting bushings '78, as indicated in Figure 5, to 110 give the required steam producing capacity.

For these, among other reasons, it is obvious that my invention discloses a compact construction for adaptation to different requirements as to output, and installation space available, with a uniform low cost of manufacture (resulting from mass production of standardized units) uniform high efliciency and low cost of replacement and repairs.

In addition to the foregoing form of structure I provide water supply manifolds which are shown in Figures 1, 2 and 3.

Regarding the water inlet, I provide a substantially U-shaped supply tube 80, each branch or arm of which has a number of downwardly disposed branch tubes 82 projecting therefrom, (as best shown in Figure 3) the ends of which may be formed integrally with plates 84. The plates 84 are secured to bosses 86 formed on each casing g and these connected parts form the outside mem- 186 bers of an assembly of boiler cells such as shown in Figure 1. The main water supply-inlet pipe 87 is joined at 88 as shown in Figure 2 to the middle of the bend in the U-shaped tube 80.

The steam outlet member also comprises a substantially U-shaped tube 90 having downwardly disposed branch tubes 92, (Figures 1 and 2) spaced along either branch of the U and preferably having their ends formed integrally with plates 94. Said plates 94 are secured to bosses 96, similar to 140 the water tube bosses 86, on the outside of each cell casing member. A main steam discharge pipe 97, is joined at 98 to the flanged end of the branch 100 from the middle of the bend in the U-shaped tube 90, and a safety valve 102 is mount- 145 ed on said tube 90 adjacent the branch 100.

The setup shown in Figure 1 is a typical installation of a steam generator system which may be enlarged or reduced in size by adding or taking away any desired number of cell units.

The units are adapted to be joined together transversely by means of the bushings 78, (see Figures l and 5) and longitudinally by means of lugs 104 welded to and projecting above the heads 12 which are secured to each other by bolts 106 shown in Figure 4.

Two structural angle iron members 108 (see Figure 4) are welded (as at 114) to the bottom of each casing and are arranged in parallel, transverse relation with their outer faces abutting (as at 109). Two heavier structural angle members 113 form the base upon which the ends of the transverse angle members 108 rest, both sets oi angle members forming the supporting base for the entire structure, and are joined together by bolts 110, 112.

The usual form of heat retaining insulation (not shown) is applied to the ends, sides and top, after an installation is made. A shield 114, (Figure 4) is supported on posts 116 above the top of the electrical connections for the purpose of supporting the said insulation and preventing the same from interfering with said electrical connections.

To maintain a constant water level within the casings 10 a boiler feed water pump 118 (Figure 2) is provided in combination with a conventional form of feed water-regulator indicated at 120, and a pressure controlled, automatic regulator 122. As this attachment forms no part of my invention and is in common use I will not describe its construction and operation further than to say that variations in water level in cylinder 120 produce the proper opening or closing movement of steam throttle valve 124, which will in turn stop, start, accelerate or slow down the operation of feed water pump 118, so as to prevent fluctuations of water level in the boiler beyond predetermined limits.

Various changes can be made in the details of construction here shown an-d described, as forming one embodiment of my invention, any such niodications still being within the scope of the invention here claimed if the principles of operation and results above explained are substantially preserved.

Having thus described my invention, I claim:

1. In a multiple-unit, electrically heated steam generator, the combination of a multiplicity of boiler cells, each cell having one open end, water inlet and steam discharge openings, a closure head for each of said open ends and a plurality of electrical heating cartridges removably mounted within each of said closures, each of said heating cartridges extending within a cell when assembled therewith, ttings secured within certain of said water inlet and steam discharge openings joining the cells together laterally and providing means for steamand water circulation between cells, a system of piping connected to the remaining steam discharge openings, a water inlet piping system joined to the remaining water inlet openings, and means for securing the cells to one another.

2. A combination suoli as defined in claim 1 in which the system of piping comprises two U- shaped manifolds each having a branch in its curved portion and a plurality of inwardly extending cranches along each arm of the U, one of said manifolds being connected to outside water inlets of the boiler and the other to outside steam discharge openings thereof.

3. An apparatus such as dened in claim 1 in which lugs are secured to each head portion, and bolts are inserted therein to secure each lateral series of generator cell units together to bring the same into longitudinal alignment, and combined with a supporting base to which each of said casings is welded.

4. A multiple unit steam boiler cell comprising in combination an elongated casing closed at the bottom and having an opening at the top, a head structure set in said top opening and forming a steam-tight joint therewith, a plurality of watertight envelopes closed at the bottom but open at the top set in openings in said cap, forming detachable steam-tight joints therewith, and extending nearly to the bottom of the casing interior, and an electrical heating cartridge removably mounted in the interior of each envelope.

5. A structure such as defined in claim 4 combined with a guide bracket located in the interior of each cell adapted to form slip joints with the lower ends of said cartridge envelopes.

GUS L. COLBIE.

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