US1789076A - Superheater boiler - Google Patents

Description

Jan. 13, 1931. H. J. KERR SUPERHEA'TER BOILER Filed Oct'.

1925 5 Sheets-Sheet 1 OOOOOOOOOO00,00000000000600000 Oggoocoooooooooooooooooooooooooooooooooooooooooooooooooooo INVENTOR- A TTORNE Y5 Jan. 13, 1931. H. J. KERR SUPERHEATER BOILER Filed 001:.

28 925 3 Sheets-Sheet 2 Ill]! llll '3! Fig INVENTOR 9- X144,

A TTORNEVS Jan. 13, 1931.

H. J. KERR SUPERHEATER BOILER 3 Sheets-Sheet 3 Filed Oct.

11v VENTOR f A TTORNE m Patented Jan. '13, 1931 UNITED STATES PATENT OFFICE HOWARD J. KERR, or wEsrEr Ln, NEW JERSEY, ASSIGNOB '110 Tim BABCOCK & wrzncox courAnY, o RAYonnE, NEW JERSEY, A CORPORATION or NEW JERSEY SUPERHEATER FOILEB- I My present invention relates to superheaters, and particularly to superheaters to be used in connection with steam boilers, and will be best understood from the. following description and the annexed drawings, in which Fig. 1 is a vertical cross-section of an illustrative form of boiler embodying my invention, the section being taken on the line 11 of Fig. 5; Fig. 2 is a section on the line 2-2 of Fig. 1; Figs. 3 and 4 arerespectively a plan and a side elevation of a detail, and Fig. 5 is an enlargement of a portion of the boiler showing an illustrative embodiment of the superheater in position. vLike reference characters indicate like parts in the several views.

The boiler which I have chosen for purpose of illustration is a typical one having an upper steam and water drum 10 above horizontally inclined water tubes divided in to a lower bank 11 and an upper bank 12, connected in the usual manner to uptake headers 13 and downtake headers 14, the gases from the furnace chamber passing across the full length of. the tubes in the bank 11, then across the space between the upper and lower banks, then over a baflle 15 and downward to a waste gas outlet 16, the gases flowing between the nipples 17.

' In the space between the upper and lower banks of tubes is a' superheater h'avin an inlet header box 18 and an outlet header box 19 extending through this space and through the side setting walls. The inlet header box 18 is connected to the drum 10- by the pipe 20, the steam outlet 21 being connected to the outlet header box 19 at the opposite side of the setting.

The header box 19 is shown suspended from the baffle 15, which, in turn, is intera locked with the tubes of the bank 12, so as to distribute the weight of the header box over a number of such tubes and the header box 18 is supported on a casting 22 resting.

on the upper row of tubes of the bank 11. The space between the header boxes 18 and 19 is covered by a bafiie 23 supported on the i header boxes 18 and 19.

The header boxes 18 and 19 are connected by U-tubes 24. extending in the same general Application filed 0tober28, 1925. Serial No. 65,274.

direction as the boilerwater tubes and being arranged preferably inv vertical and horizontal rows, there being three horizontal rows of such tubes in the form illustrated. The ends of the tubes where they are entered into the header'boxes 18 and 19 may be protected from the heat in any suitable manner, and the weight of the tubes themselves may be carried on piers resting on the tubes 11, one form of such construction being shown in Fig. 5, there being a number of piers 25, 26, on which rest metallic walls 27 through which the tubes 24 extend. The particular method of supporting the superheater is no part of my present invention and further description thereof will be unnecessary.

The superheater which I have illustrated,

- the tubes of this group into the header 18",

'then along this header to the group 24", and

then through these tubes into the header 19 to the outlet pipe .21.

It will be noted that the several groups of superheater tubes 24, 24" and 24' have a substantial space between the adjacent groups. Heretofore multiple-pass superheaters have been constructed with the tubes and headers arranged somewhat as shown in the annexed drawings, but with the tubes defining the adjacent sides of adjacent groups close together. When the tubes enter theheaders in the manner heretofore in use, it will be observed that the steam flows into the header from one group of tubes and out of the header through another group of tubes, with the steam entering the header from some tubes being required to substantially reverse its direction of flow in the header in order to leave the header through site the end of the adjacent tube where the steam is leaving the header, if the entrance and exit points of the steam are closely adj acent, as they have been made heretofore. This lowering of the static pressure will reduce the amount of steam flowing into such adjacent tube or may actually prevent any flow into that tube. Therefore, the distribution of the steam through the several tubes of each group has heretofore been unequal. Attempts to correct this have been made by the use of ferrules to equalize the flow through the several tubes, but obviously such ferrules increase the frlctional resistance through the superheater as a whole.

In my present invention,I provide a substantial space between the most closely adj acent inlet and outlet tubes in a header, so that the nearest outlet tube is far enou h away from any inlet tube to be out of t e area of low pressure set up around the inflowing steam from a tube. The velocity of the steam flowing into the header is therefore absorbed and the static pressure equalized before the steam reaches an exit tube, and therefore the inertia effect of the inflowing steam is overcome, so that the steam can distribute itself freely amongst the several outlet tubes from that header.

In the arrangement illustrated, it will be notedthat the space between the side tubes of the adjacent groups 24' and 24", where the ends of such tubes enter the header 19, is a wide one and very much' wider than the space between the tubes of the group measured alon the header 19'. A similar space is provi ed between the ends of the tubes of the roups 24" and'24 where such tubes enter t e header 18".

What I do in practice in constructing a superheater of the type illustrated is to omit a number of the superheater tubes as they would normally be inserted, thus producing the desired space between the ends of the several groups. I also utilize this space or any similar space obtained by omitting certain of the superheater tubes in order to regulate the flow of gases over the superheater tubes and the degree of superheat to be given'to the steam superheater.

, It will be noted that the gases flowing-up from the furnace chamber and across the tubes 11 would normally flow vertically over all of the tubes 24 and if the spaces between the several groups did not exist, the gas passing through the groups of superheater tubes.

flow would be substantially uniform over all of the tubes. Y

It isdesirable',,however, at times to vary the gasflow over the superheater to regulate the degree of superheat, and to this end, I provide below the spaces between the several groups of superheater tubes, dampers which will serve to regulate the flow of furnace none of such gases flow over the tubes, and,

of course, "any adjustments between such limits.

In the specific form illustrated, I have provided between the piers 25 and 26 and supported on the bottom plates 25 and 26' of such piers, a sliding damper 30 for each of the spaces between a pair of adjacent Each damper is shown in Fig. 1 positioned beneath one of such spaces and is connected at either end to an operating rod 31 extending through the setting wall and provided on the end with a rack 32 engaged by a gear 33 on a shaft rotated by a worm and worm wheel 34to be turned by a rod 35. By rotatin the rod 35, the dampers 30 can be moved zontally either into or outof a position directly below the spaces between the groups of superheater tubes, to either divert gases from such spaces or to permit them to flow therethrough.

It will be understood that the embodiment of my invention maybe widely varied and that many of the features may be used independently of other features. 1

Obviously the damper arrangement for controlling the flow through the spaces between the groups of superheater tubes may be widely varied. It will also be understood that it is not necessary to provide a damper which will do more than divert more or less of the gases from such spaces because such adegreeof divergence is sufficient to-provide the amount of regulation ordinarily required. It will also be understood that while I have shown a multipleass superheater in my illustrative embo iment, the provision of spaces and a damper to control the flogv of gases through the same may be used in a single-pass superheater as well as in a multiple-pass superheater, the entire set of su erheater tubes in such case be-.

ing divided mto groups with a space between each pair of groups and a damper to oricontrol this space. In other words, 'for oerhaving a bank of tubes above said water tain features of my invention, it is imma-i terial whether the several groups of superheater tubesare arranged in parallel or in series.

I claim: y

1. In a steam boiler, two spaced .banks of horizontally inclined boiler tubes, a bank of superheater tubes located in the space between said banks of boiler tubes, said bank of superheater tubes beingdivided across the flue into at least two groups of tubes witha free unoccupied space between the groups, and means movableacross said space for regulating the flow of the gases oversaid superheater tubes by varying the amount of flow through said space.

2. In a steam boiler, two spaced banks of horizontally inclined boiler tubes, a bank of '.superheater tubes located in the space between said banks of boiler tubes, saidbank of superheater tubes being divided across the flue into at least two groups of tubes with a free unoccupied --space*between the groups, and a damper movable across said space for regulating the flow ofthe gases over said superheater tubes by varying the amount of flow through said space.

3. In a steam boiler, a boiler flue for furnace gases, a bank of superheater tubes eX-' tending across the flue in the path of the gases flowing therethrough, said bank being divided across the flue into at least two groups of tubes with a free, unoccupied space between the groups, and a sliding" damper movable from a position in front of said space to a position in front of one of said groups.

4. In a steam boiler, a boiler flue for furnace gases, a bank of superheater tubesextending across the flue in the path of the gases flowing therethrough, said bank be ing divided across the flue into at least two groups of tubes with a space between the groups, and a movable damper extending in the same general direction as said superheater tubes for at least the major portion of the length of the tubes in said flue and movable from a position in front of said space to aposition in front of .one of saidand positioned adjacent said space to regulate the flow throughsaid space of the gases flowing over the water tubes and across the superheater tubes.

6. In a steam boiler, a bank of horizontally extending water tubes, a superheater divided into at least two groups of tubes,

side by side, with a space between the groups,

a pair of plate supports spaced apart and supported on the top of the bank of water tubes, a plate damper having its ends slidingly supported on .said plate supports and movable sidewise thereon from a position beneath said space to a position beneath one of. said groups of superheater tubes, and means operable from the'exterior of the boiler setting, to move said dampen 8. A superheater having apair of sub stantially parallel header boxes, one of said boxes having a partition to divide it into two headers, two groups of tubes connect-' ing said pair of boxes, each header of said partitioned header box being connected to the ends of the tubes of a group, each group having at least one row of tubes and all of the other ends of the tubes of both groups being connected to a common-header, with a substantial space between the endsof the tubes in the respective groups which are nearest the ends of the tubes of the other group, the width of said space bein ,at' least two tube diameters and the diameter of a common header being less than the combined diameters of the tubes of a given row.

'9.- A superheater having headers and tubes connecting the headers, said tubes being divided into groups with aplurality of, tubes in each group, each group having at least one row of tubes, said; tubes and headthe steam to flow successively through-the tubes of the several groups with the ends of the tubes of at lea'sttwo adjacent groups connected to the same header and with a substantial space between the ends of the tubes in the respective groups which are nearest the'en'ds of the tubes of the other group, the width of said space being at least twoftubediameters and the diameter of a common header being less than the com bined diameters of the tubes of a given row.

10. In a steam boiler, a boiler flue for furnace gases, a bank of tubes for a fluid heater extending across the flue in the path of the gases flowing therethrough, said bank being 'divided across the flue into at least two grtzpps of tubes with aspace between the grou s, and a movable damper extending in t e same general direction as said tubes of said fluid heater for at least the major portion of the len h of the tubes in said flue and movable rom a osition in front of said space to a position 1n front of one of said groups.

11. In a steam boi1er, a bank of horizontally'extending water tubes, a fluid heater having a bank of tubes above said water.

tubes, the tubes of said fluid heater being divided into at least two groups with a space between said groups anda damper supported on and movable alon said water tubes, the damper being of'su cient size to span the space between said grou s and a movable from a position beneath sai space to a position beneath one of said groups of tubes of said fluid heater.

-' a v HOWAIZED J. KERR.

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