US1140116A - Steam-superheater. - Google Patents

Description

'W. F. J. CASEY.

.STEAM SUPERHEATER.

APPLICATION FILED 001.21, 1913.

Patented May 18, 1915.

W/f/msses THE NORRIS PETERS C0,. PHOTO-LITHQ. WASHINGTUN. B4 c.

UNITED srarns PATENT orruon i WILLIAM F. J. CASEY, OF KINGSTON, ONTARIO, CANADA, ASSIGNOR TO LOCOMOTIVE SUPERHEATER COMPANY, OF NEW YORK, N.

Y., CORPORATION OF 1)ELIAVVARE.

STEAM-SUPERHEATER.

Application filed October 27, 1913.

.heater in which the course of the steam is made as direct as possible.

Further objects and advantages will be apparent to those skilled in the art to which this invention relates from the following description. 7

At the present time, superheaters consist as a rule of a number of superheating units or loops connected at their opposite ends to headers. Each loop as a rule occupies a single fire tube of the boiler, these tubes being preferably spaced equidistantly. As there are obviously as many superheating units as fire tubes, it will be seen that a'large number of connections require to be 'made 7 between these units and the headers.

In the present invention, the fire tubes of Y the boiler are arranged in vertical rows as usual,but the spacing of these vertical tube rowsis irregular, so that the tubes are arranged in spaced groups. The superheater units are arranged in theform of a number of loops arranged in a horizontal plane, each loop entering a fire tube, so that each unit passes through a plurality of fire tubes,

The heating units are preferably arranged in pairs one below the other. The'wet or saturated steam is delivered from the boiler into a header having a plurality of branches arranged in front of alternate spaces between the groups of fire tubes. Thesefheader branches are connected to one end of each heating unit, the opposite ends of said units being connected to collectors disposed intermediate the headerbranches. These collectors are arranged in line with and are merely extensions of the steam pipes to the engine cylinders, so that the steam travels in the most direct .pathlpossible.

Specification of Letters Patent.

7 Patented May is, 1915.

Serial No. 797,598. I In the drawings which illustrate the invention :Figure 1 is a half front elevation of the superheater partly in section. .Fig.'2

is a vertical sectional view on the line 2-2,

.Fig. 1. Fig. 3 is a fragmentary sectional view on the line 3-3, Fig. 1. Fig. 4 isa sec- 1 tional view of the connecting means between the heating units and header or collector.

I Referring more particularly to the drawings, 5 designates a boiler shell having front and back tube plates 6 and 7 respectively, between which are supported aplurality of fire tubes 8. The smoke boxat the front end of the boiler in whichpart of the"superheater is located is designated 9. The fire tubes are preferably arranged in vertical rows, as shown in Fig.1, said rows being spaced alternately close together and far apart, as shown in Figs. 1 and 3, so that the firetubes are'divided into a plurality of groups. p I r The wetor saturated steam header 10 and the dry or superheated steam collectors 11 are formed ina-singlecasting, having at[ the top a neck 12 to which the steam supply pipe is connected and at the bottom a pair of necks 13 located one on each side of the center, so as to be connected directly to the engine cylinders by a short length of pipe.

The wet'steam header is provided with three depending branches, namely, a center branch 14 and two comparatively small side branches 15. The center branch 14 .is located opposite the'space between the two central groups of fire tubes, and the small branches 15 are located just beyond the outer groups of fire tubes. The dry steam collectors 11 are 'located intermediate the same capacity as the'three header branches.

The header.branches and collectors are suitably tapered to give a uniform distribution at all points, as is shown in Fig. 2.. The lower ends of each of the header branches are connected by integral straps or stays 16 with the lower ends of the collectors, while the upper ends of the collectors are connected by similar but shorter' branches 14 and 15 and opposite the spaces stays 17 with the header 10, these stays being spaced so as to leave a clear air space 18 between the end of the dry steam collector and the wet steam header. This air space prevents transference of heat from the superheated to the unsuperheated steam at the only point where the several passages meet. The stays 16 and 17 rigidly connect the wet and dry steam passages, so that there cannot be any relative movement between them, which movement would obviously produce an unnecessary stressing of the superheating units connected between them and would also cause leaking at the joints.

The superheating element consists of a plurality of units 1.9 each formed preferably of four straight tubes 20 connected in series by return bends 21 or loops 22. In the arrangement shown in the drawing, each unit 19 consists of a tube extending rearwardly from awet steam header branch and through to the rear of a fire tube where it is connected by a return bend with a forwardly extending tube, which is looped or bent on itself at 22 and extends to the rear of the next fire tube. Another return bend is used to connect this looped tube with the forwardly extending tube, which in turn connects with a collector 11. The unit thus formed is disposed in a horizontal plane, so that it passes into each fire tube across the group. The arrangement of fire tubes in alternately adjacent and separated vertical rows, as previously stated, causes there to be two vertical rows of fire tubes between each collector and the header branches on either side thereof. In this way, each heating unit passes through two fire tubes. By

multiplying the number of fire tubes, the 7 groups may be made to contain three vertical rows, so that each heating unit passes through three fire tubes. On the other hand, with the present number of tubes, the outer branches 15 may be eliminated by enlarging the central branch 14:, and each collector placed outside the tube groups, so that the heating units pass through four tubes.

The connection between the ends of the heating units and the header branches or collectors may be of any suitable type, but is preferably of the star type shown in the drawings, as by this means four units may be connected to a single opening in the branch or collector, thus strengthening the latter. This star connection consists of a body 28, having a tapered-neck 24 screw threaded into the branch or collector. A suitable number of externally threaded nipples 25 radiate from the body. The ends of the units are taper screw threaded into the elbows 26 provided with flanges 27 engaged by suitable coupling nuts 28, which screw on to the nipples 25. The seat surface 29 on the flange end of each elbow is preferably spherically curved, and cooperates with a similarly curved seat on the nipple, so that a tight joint may be readily maintained.

The wet steam enters the superheater through the neck 12 and fiows into the branches l4 and 15 in properly proportioned amounts. The tapering branches distribute the steam evenly to all the heating units. The steam then flows through the units passing back and forth through the fire tubes, and is finally delivered into the collectors 11 from which it passes directly to the pipes connecting with the cylinders, without the necessity of flowing through the tortuous passages of any header arrangement. It will be seen from the drawings that the steam travels the length of the fire tubes four times in passing through each heating unit, and thereby becomes thoroughly dried and superheated so as to have the increased efficiency desired.

From the foregoing description, it will be readily seen that the superheater consists of a very small number of parts of great simplicity and durability. The front casting is much lighter than the usual type, much simpler to make and much stronger, owing to the reduced number of openings. The superheating may be said to be in two stages, that is, each heating unit is surround by two entirely separate and distinct currents of hot gases, so that should the heat in one fire tube be below normal, the heat in another tube will prevent the mingling of imperfectly superheated with perfectly superheated steam. The tubes themselves are perfectly straight and not upset, so that they may be supplied at a minimum cost. Any heating unit may be removed independently of all others for cleaning or repair. 1

Having thus described my invention, what I claim is 1. In a superheater, the combination with fire tubes arranged in horizontally separated groups each group having a plurality of horizontally disposed tubes, of a wet steam distributing header having branches depending integrally from said header in line with alternate spaces between tube groups, an engine steam pipe for each side of the engine having a single vertical prolongation in line with one of the remaining spaces between tube groups, and superheating units connected between a branch and one of the said prolongations, each unit traversing all the horizontally disposed tubes of the group.

2. In a superheater, the combination with fire tubes arranged in horizontally separated groups each group having a plurality of horizontally disposed tubes, of a wet steam distributing header having branches depending integrally from said header in line with alternate spaces between tube groups, an engine steam pipe for each side of the engine having a single vertical prolongation in line with one of the remaining spaces between tube groups, and superheating units connected between a branch and one of the said prolongations, each unit traversing all the horizontally disposed tubes of the group, the header, branches, and prolongations being integrally united together.

3. In a superheater, the combination with four horizontally disposed and spaced groups of flue tubes each group having two vertical rows and the distance between groups being greater than the distance between rows, of a wet steam distributing header having a branch depending integrally from said header on each side of all the groups and a third branch depending integrally between the second and third groups, an engine steam pipe for each side of the engine having a single vertical prolongation in line with the spaces between the first and second and between the third and fourth groups respectively, and superheating units connected between the branches and the prolongations, each unit traversing each horizontal flue tube of the group.

4:. In a superheater, the combination with fire tubes arranged in horizontally separated groups each group comprising a plurality of vertical rows of horizontally disposed tubes,

of a wet steam distributing header having branches depending integrally from said header in line with alternate spaces between tube groups, an independent steam conduit for each side of the engine leading to the steam chest and having a portion in line I with one of the remaining spaces between tube groups, and superheater 7 units connected between branches and engine pipes, each unit traversing all. the horizontally disposed tubes of the group,

5; In a superheater, the combination with fire tubes arranged in horizontally separated groups, each group comprising a'plurality of vertical rows of horizontally disposed tubes, of a wet steam distributing header having branches depending integrally from S. R. W. ALLEN, G. M. MORELAND.

Copies of this patent may be obtained for five cents each, by addressing, the Commissioner of Patents, Washington, D. G.

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