US1379409A - Steam-superheater - Google Patents

Description

C. A. HORN.

STEAM SUPERHEATER.

APPLICATION man SEPL is, 10:9A

y 2li, 1921.

` mmm..

UNITED 'STATES PATENT OFFICE.

. CHARLES AZ'HORN, OF WOODHAVEN, NEW YORK, ASSIGNOR OF ONE-FOURTH T0 W. EVERITT BUNDLE, OF EAST ORANGE, NEW JERSEY, AND ONE-FOURTH TO HAROLD E. LOMBARD, OF BLOOMFIELIL NEW JERSEY.

STEAM-SUPERHEATER.

Specification of Letters Patent.

Patented May 24, 1921.

Application filed September 13, 1919. Serial No. 323,508.

To all whom 'it may/concern.'

Be it known that I, CHARLES A. HORN, a citizen of the German Republimresiding at lVoodhaven, in the ce" of Queens, city and State of New York, have invented certain new and useful Improvements in Steam-Superheaters, of which the following is a full,`clear, and exact description.

. This invention relates to steam superheaters, and its chief object is to provide a superheater .inwhich the tubes are internally braced or reinforced to resist sagging or bending, to enable long tubes to be used without the employment of Objectionable intermediate supports in the path of the hot gases. Another object is to provide an internall reinforced superheater iii which the reinforcing structure provides a plurality of passages in each tube. through which the steam iiows in succession, thus permitting the use of tubes of large diameter with high steam velocity therethrough. A further object is to provide a superheater in which the steam passages `decrease in length as tlie'steam approaches the outlet of the supei'heater, thus securing a Substantially uniform velocity throughout. To these and other ends the invention con` sists in the novel fea-tures andfcombinations 3 3 of Fig. l.

Fig. 4 is a longitudinal section through one tube and part 'of the header, showing a modification.

-Fig. 5 is a cross section on line 5-5 of Fig. 4. Y y

ig. 6 is 'a longitudinal section through one tube and part of the header, showing`- another modification.

Fig. 7 is a cross section on line 7-7 of theinner surface of the tubes closely, thus dividing each tube into two (or more) pas* sages. The steam, entering the first tube,

AHows out tl'irough one passage ,to the end of the tube, then back through the other passage to the header; then out and back through the next tube, and so on through the tubes in succession, as indicated by the arrows iii Fig l,fi1ially emerging from the outlet 23. Each tube is therefore in effect two tubes, and hence I am able to use tubes of larger diameter and proportionately greater stiffness, at the same time obtaining the advantages of smaller tubes as regards steam velocity and heat transference. Preferably the partitions or battles are twisted, as shown, so that .the steam is forcedto take a helical orvscrewpath. This givesa radial component of motion to the steam, tending to throw the f steamradially outward against the surface of the tubes. This effect is very marked at high steam velocity, and materially increases the rapidity of heat transference from the furnace gases to the steam.

f It is important that the partitions lit the tubes tightly, preferably by adriviiigfit, so as to be iii firm contact with the tubes throughout. This facilitates conduction of heat to the battles and thus makes the latter an effective part of the heating surface and by eliminating or minimizing relative mo;-

tion between the tube and the baiiie, it enables the latter to serve as an inner truss, so stilfening the tube as to practically prevent sagging under high temperatures. I am therefore able to use longer tubes, with out intermediate supports between their ends, and can subject the suj'ierheater to higher temperatures, without risk of the injurious distortion so frequently encountered in prior apparatus.

As the steam 'Hows through the superheater its temperature, and hence its volume per unit weight, increases. I therefore progressively increase the pitch of the partitions froin the inlet to the outlet, the first 2 navegue partition having the greatest number of turns and the last having the least number,

4as'clearly indicated in Fig. 1. This gives a fairly uniform velocity throughout and makes the several tubes equally eflicient.

The twisted orv screw-type partition has y 'another important advantage, in that the 'ffpassages are intertwined, in effect mixing z*the two currents of steam together. This equalizes the temperature of the tube and 'its` partition, and practically prevents the jimequal expansion, and consequent injuri- ''fous distortion, that sometimes results when l thetwo currents are confined to separate Sides of the tube o r are caused to How outwar'gdly through one tube and back to the header through another tube.

The partition may be of luniform cross gction, but I prefer to provide it with a central longitudinal stiffening rod or bead,

" Jasindicated at 25.

A two-blade bailie or partition as in Figs.

l and 2, is usually adequate, but three or more blades may be used if desired. Figs. `tand villustrate a four-blade construction, g "24a, providing two ingoing channels, a and -b','fa`nd two outgoing channels, c and-d.

Figs. 6`and 7 show a founblade construction 'i in which theA partition, 24h, is straight instead of 4 being twisted. This gives the 'highl advantageous truss effect for stiften;

f ing it, e tubes but does not take care of unfequalt expansion due to difference in temperof the ingoing and outgoing steam. As` made up4 for use with a steam boiler 1 the complete superheater usually consists f two or more sections such as are described above, each section or unit consisting of a lheader and two or more tubes. p

Itis to be understood that `the invention `is not limited tothe specific constructions herein illustrated and deseribedfqbut can/-be embodied in other forms withoutQdeparture from its spirit.

I claim: y 1. In a steam superbe-atei', two tubes througlwhich the steam Hows in succession,

and each having a twisted or helical partition to provide helical steam' passages, the pitch of the partition in the second tube being greater than the first, .and means serially connecting said tubes.

2. A steam superheater comprising in combination, a header having inlet and outtitions extending across the header and into the tubes to a point near the outer end of the latter, dividing the tubes into a plurality of helical ingoing and helical outgoing pasages communicating through theA header, the partitions at the outlet of the header having fewer turns than the'partitions' at the inlet.

4. A steam superheater comprising in combination, a tube having a substantially uniform cross-section, `a second tube having A asubstantially uniform crosssectional area, on a plane at right angles to the' tube axis, substantially equal to the internal crosssectional area of the first tube on a similar plane, means in said first tube, and in conjunction with the inner wall of said first tube, forming a steam passage of greater length than said first tube but of "lesser effective cross-sectional area than the first named crosssecti on, means in saidsecond tube and, inconjunction with 'the inner wall of said second tube, forming a steam passage of greater length than,sa id second tube but of greater eii'ective crosssectional area than the effective cross-sectional area of the first mentioned passage, and means'serially I connecting said passages.

In testimony whereof I hereunto'afix my signature. y

- CHAR-LES lA.. HORN.

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