US1931639A - Superheater - Google Patents

Description

Oct. 24, 1933. w. H. ARMACOST 1,931,639

SUPERHEATER Filed Aug. 8, 1932 INVENTOR \A/Hbmr H. Avvnucos ATTORNEY Patented Oct. 24, 1933 v N E AT S' SUPERHEA'IER Wilbur H. Armacost, New York, N. Y.,' 'assignor h to The superheater Company, New Yo'rk, N. Y.

Application August's, 1932. JSerial No."627,855 1 4 Claims 01. 122-473) My invention relates to superheater boilers and aims to provide an arrangement whereby the final steam temperature of such an installation may be adjusted without disturbing the distri- 5 bution of steam in the superheater elements or increasing the drop in pressure across thesuperheater. v

The novel features of my invention are pointed out in the appended claims. In order,-however,

advantages thereof, may best be understood, '1 will 'now describe in detail and in connection with the accompanyingldrawing a superheater,

It has been proposed heretofore to provide a boiler with a superheater having two groups of superheater elements and means whereby some of the steam can be passed around one of such groups to vary the final temperature of the steam from the superheater. Such an arrangement, however, as proposed prior to my invention involves disturbing the distribution of the steam thru one of the groups of elements, if not both, so that certain elements may become overheated. It is, of course, also always; possible to decrease the final superheat temperature by removing certain elements, but such an expedient involves increasing the pressure drop across the entire superheating means. An arrangement within my invention avoids the difficulties just mentioned.

The superheater boiler illustrated in Fig. 1 is 40 similar in general to that illustrated in my prior application, Serial No. 530,739, filed April 16, 1931. However, I do not limit myself to any particular type of boiler. In the arrangement shown, 10 is a steam and water drum from which extend downcomers 12, 12 which run along one side of the boiler to lower vertical headers 14. From the headers 14, a group of generating tubes 16, 16 extend laterally and upwardly to upper horizontal headers 18 which are connected to the drum 10 by circulators 20 and 22. A second group of generating tubes 24 extend somewhat parallel to thetubes 16 and connect into the headers 14- at their lower ends but run directly 7 into the drum 10 at their upper ends.

Between the tubes 12 and the tubes 24 I have that the invention, together with the objects and load if all the space available for the supershown a large number of economizer tubes 26, 26 and 28, 28. I Water for the drum 10 is introduced thru the header 30 and flows downwardly thru the economizer tubes'26 to'an intermediate head-- er 32 and then upward thru economizer tubes 28 to anoutside header 34, which is connected to "the drum 10 by pipes 36, 36. It will be seen also 'thatthe boiler shown in Fig. l is intended for a double set arrangement having a right hand portion duplicating the portionillustrated. All the foregoing features, however, form no art of the present invention. p

The generating tubes 16 are spaced from the tubes 24 to provide "room for a group of; primary superheater elements 40 which are connected between an inlet header 42 and an-intermediate header 44'. A "groupflof secondary superheater elements 46, is connected between the intermediate header 44 and an outlet header 48. Broken off portions 46 of superheater elements, not shown but assumed to lie in the right hand of the boiler, appear in Fig. 1. As shown, elements 46 are arranged in lanes between the gen-- erating tubes 16, but the relationship of the superheater elements to the generating tubes forms no part of the present invention. In the arrangement shown, flexible nipples 50 are connected into the drum 10 for conducting steam therefrom to a header 52 which connects in turn to the inlet header 42 of the superheater by bend 54. However, I do not limit myself to any particular means for conducting the steam to the inlet header of the superheater.

It is often very difficult to predetermine the outlet temperature of steam from a superheater boiler at a given load. In accordance with my invention, room is provided in the boiler for an ample amount of surface to insure that the desired temperature may be obtained at a given heater is utilized. In many cases, however, the final temperature of the steam will then be greater than desired. In order to make the necessary adjustment in the final temperature of the steam, I omit some of the superheater ele ments for which there is room and connect between the headers of the group from which they have been removed by-passes 60, 60 which lie outside the path of the heating gases, but have each substantially the conductance for or resistance to flow of a pair of elements for which it is substituted. By conductance for flow is meant the flow per unit time caused by a given pressure difference across the ends of the element in question. Similarly, by resistance to flow is meant the pressure difference across the ends of a given element measured at a given rate of fiow. There is shown in Fig. 1 the elements connected in pairs at given planes transverse to the headers 42 and 44 and a single by-pass is connected in place of a pair of such elements at each of several different points along headers 42 and 4.4 (Fig. 2). The distributionof steam along the headers is .thus substantially unaltered and the same is true as to the drop in pressure between inlet header 42 and outlet header 48. As shown in Figrl elements 40 are of the removable type so that by-passes 60 can be readily substituted therefor. When one by-pass 60 is substituted for a pair of elements it is not usually the case that the by-pass, or by-passes can utilize the same apertures as one or more of the elements. eral, therefore, the apertures for the Joy-passes are in difierent faces of the headers from those for the elements. Ido not limit myself to this, however. Of course, when any of the apertures, either for elements or by-passes are not being utilized while the apparatus is in operation,

" such aperturesare closed by plugs, not shown.

It is preferred, moreover, to utilize by-passes 6,0, or the like, between the inlet header and an intermediate header rather thanbetween an in-- termediate header and the outlet header. The elements such as 46 which carry the steam or higher temperature thus always carry the full volume of steam and are thereby protected against overheating to the maximum, extent. However, I do not limit myself to this.

What I claim is:

1. A. superheater having a group of primary and a group of secondary elements, headers for said groups, certain of said elements being readily removable, and relatively short unheated by In genpass connectors at certain points on said headers at places adapted to receive certain of said removable elements, said connectors each having substantially the same conductance for flow as a superheater portion for which it is adapted to be substituted.

2. The method of reducing to a desired point the final, steam temperature at a given load delivered by a superheater having primary and secondary superheater elements which comprises substituting a sufficient number of primary elemerits by relatively short substantially unheated by-pass connectors whose individual resistance to flow equals the resistance to flow of the portions of. the superheater for which they are substituted. V

3. A superheater having a group of readily removable superheater elements, headers for said group, said headers having certain positions adapted to receive superheater elements but which are unoccupied by elements, and relatively short unheated by pass connections between said unoccupied positions of the headers, said connectors adapted to maintain the conductance for steam flow from header to header the same as if the maximum number of elements permitted by the headers were in use.

4. Asuperheaterhaving a group of primary and a group of secondary units, headers for said groups, certain of said units being readily re movable, and relatively short unheated by-pass connectors between certain points on the headers for .said primary group in zones adapted to receive certain of said removable elements, said connectors each having substantially the conductance to-flow of a superheater portion for Whichit is adapted to be substituted.

WILBUR vH. ARMACOST.

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