US2104155A - Superheater - Google Patents

Description

F. l. EPLEY Jan. 4, 1938.

SUPERHEATER Filed Sept. 25, 1934 INVENTOR. Fkfofk/ar j." EPLEX By a A TTORNEY Patented Jan. 4, 1938 UNITED STATES PATENT OFFICE SUPERHEATER Application September 25, 1934, Serial No. 745,415

1 Claim.

My invention relates to a superheater and a form of unit therefor whereby a material proportion of the weight of the units may conveniently be transferred to the headers to thereby reduce either the cost of high temperature unit supports or the amount of weight on the boiler structure or both.

In order that my invention may be fully and readily understood, I will now describe in detail and in connection with the accompanying drawing a superheater boiler in accordance with my invention and selected by way of example from a number of possible embodiments thereof. In the drawing,

Fig. 1 is a vertical sectional view of a superheater boiler whose superheater is designed in accordance with my invention.

Fig. 2 is a fragmentary section on the line 2-2 of Fig. l.

The arrangement illustrated in the drawing comprises a portion IU of a well-known type of horizontal straight tube boiler including an upper group I2 of generating tubes spaced vertically above the lower group I4 of generating tubes, group I4 being set above the furnace chamber IS in the usual manner. Between group I2 and group I4 is a chamber [8 at least part of which is commonly utilized for a superheater l9. As illustrated, the chamber l8 between the two groups l2 and i4 is divided by bafiling 28 into a plurality of gas passes and I have utilized only the first pass for the superheater units. "The superheater l9 comprises two headers 22 and 24, the former being shown outside the boiler structure and the latter in the gas space behind the bafiling 20. However, I do not limit myself to any particular arrangement of the headers. Between headers 22 and 24 are connected a plurality of serpentine units 26, 28 each of which includes a plurality of loops 28, 28. Units 26 lie in vertical planes so that the loops 28 of a given unit lie one above the other and I have utilized this arrangement to improve the manner of supporting the units. As illustrated, the top loop 28 is employed as a girder being reinforced so as to support the weight of the loops below it. For this purpose, I have shown a plate 38 preferably of mild steel between the two pipe runs of the top loop 28 of each unit, plate 38 being welded or otherwise securely fixed to the pipe runs of top loop 28 at a sufficient number of points to stiffen the top loop so that it can act as a girder. As shown, bodies of weld metal 3|, 3! are shown between the plate 38 and the top loop 28 for the entire length of such plate, but I do not limit myself to this.

It will be seen that the top pipe run of the top loop 28 extends out to header 22 so that weight carried by such top loop is transmitted readily by the pipe to the header. In order to transfer the weight from the other end of the top loop 28 to header 24, the bottom run 32 of each unit is extended up along one side of the unit and the end of the top loop opposite header I 22 is fixed to such extension of the pipe length 32, weld metal 34 being shown for this purpose. From the point of connection 34, pipe 32 is extended to the header 24 thereby transmitting the weighton the top loop 28 in part to such header. Between the top loop 28 and the pipes below it, I have shown a series of dovetailed supports 36, 36, commonly known as slip spacers, for transmitting the weight of the lower loops to the upper one. Such slip spacers are in common use and, while considered the most convenient means available for the purpose mentioned, I do not limit myself to such a type of support.

In the arrangement illustrated, the entire weight of the superheater is shown as carried on the headers 22 and 24. Except in the case of light units such an arrangement may involve an increase in weight of metal in the headers and sometimes auxiliary supports will need to be employed to transmit some of the weight to the boiler structure. In any event, my invention permits the elimination of uncooled supporting structures in the hot gas zone necessitating heatresisting metal having a high price per pound. This will be seen to follow from the fact that the parts 38, 34 and 36 of the structure are all cooled by the direct or intimate contact of the metal in the units 28 and any auxiliary supports which may be needed can be placed either in the cooler gas zone back of the baffling 20 or can be clamped to the connecting nipples 38 extending between the upper and lower groups 48 and 42 respectively of boiler headers.

What I claim is: 1

In a superheater having a pair of horizontally spaced, parallel headers and heat absorbing units each comprising vertically spaced pipe runs serially interconnected by return bends to form substantially horizontally extending loops; stifiening means fixed between the pipe runs of the topmost loops of a unit to form a girder thereof which is located intermediate said headers; means for freely suspending the loops below said topmost loop from said girder; and means for supporting said girder from said headers comprising a lead connecting the topmost loop to one of said headers and a connection between the return bend of said topmost loop and a lead extending from the lowermost loop to the other header.

FREDERIC I. EPLEY.

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