US1759011A - Reheater - Google Patents

Description

May 20, 1,930.

Filed Nov. 30, 1928 2 Sheets-Sheet 2 INVENTOR. fin d/e- Huzt .-1 TTORNEY.

Patented May 20, 1930 UNITED STATES PATENT OFFICE ANDRE HUET, or rams, amen, nssrcnon To run surnnnna'rnn comm, or

' NEW YORK, 1v. Y.

BEHEATER application filed November 30, 1928, Serial No. 322,870, and in France April 30, 1928.

This invention relates to reheaters in which interstage steam, that is, steam from one stage of an engine flowing to the subsequent stage where it is to expand further, is reheated by means of superheated live steam .of higher pressure and temperature before being delivered to the second stage.- The invention has for its purpose the provision of apparatus of this type which shall be more economical in construction and operation than devices of this typehave been heretofore and which shall have certain other advantages appearing from the following specification. v

The invention is illustrated in the two sheets of drawings herewith, in which Fig. 1 is a vertical, central section of an apparatus according to my invention; Fig... 2 is a section on line 22 of Fig. 1, certain portions being omitted for the sake of clearness; Fig. 3 is a view on a larger scale of a portion of Fig. 1; Fig. 4: is a vertical, central section of a second form of the'invention; Fig. 5 is a section on line 5-5 of Fig. 4; and Fig. 6 is a section on line 66 of Fig. 5.

Referring first to the form of my invention illustrated in Figs. 1, 2 and 3, 1 is a casing or drum through which flows the fluid to be heated. This fluid, as mentioned. above, is ordinarily interstage steam which will usually enter in a saturated form and leave the casing in a superheated condition. The steam entersat 2 and leaves at 3; The baffle 4 causes it to flow first upward over the upper edge of the battle and then downward. The fluid by which the interstage steam is tobe heated enters the header 5, this header having connected to it a'number of serpentine or zigzag coils 6-6 which lieinthe upper portion of the upward pass between the casing.

and the baflie 4. These serpentine coils 6 are of small internal diameter so that the flow of the steam through them is comparatively very rapid.

Each of these serpentines 6 is connected by means of a tube 7 to a header 8. These headers 8 are arranged in a parallel position in the lower portion of the pass andat rightangles to the header 5. Connected to each header 8 is a series of vertical tubes 9-9, the upper ends 1010 of which are closed, as will be more clearly seen in Fig. 3 where one of these other headers 8 with the connected pipes is illustrated on a larger scale. Below the headers 8 and transversely to them is arranged a pipe 11 to which the headers 8 are connected by means of the pipes 12. The outlet from this pipe 11 is shown at 13, Fig. 2.

The steam entering the header 5 is, as men- 1 tioned above, superheated steam of a pressure higher than the interstage steam. The

transfer from superheated steam is diflicult While rapid flow might also facilitate heat transfer at this stage, the friction losses caused by such greater velocity would much more than olfset the gain. In my apparatus, therefore, I eliminate rapidity of flow entire- .ly and permit the steam to condense under practically stagnant conditions. As the steam condenses, the resulting condensate flows down the sides of the tubes 9 into the headers 8, being replaced by other steam that enters at the lower ends of the tubes 9 and rises up into them. This flow of the steam is comparatively very slow and no appreciable losses are encountered.

The condensate collecting in the header 11 is removed from the connection 13.

- flow through The nature of my invention will now be understood. It consists essentially in causing the heating steam to flow at a high rate of speed as long as it is superheated, and keeping it in a practically stagnant condition while it is giving up its latent heat of vaporization.

A second form for carrying out my invention is illustrated in Figs. 4, 5 and 6. The steam to be heated in this apparatus enters at 2 and is directed by suitable bafliing toward the outlet 3, its flow being indicated by the arrows in Fig. 4. The superheated high pressure heating stealn enters the header 5 (which in this case lies outside of the casing 1). The serpentine coils 6=-6 are connected to this header 5 and deliver the steam flowing thrpugh them to the headers 1414. It will be noted that in this arrangement two serpentines 66 connect to each header 14. This is a matter of choice and under some conditions it may be preferable to have only one connected to each header. From the headers 1414 extend downwardly the bifurcated elements 1515, their lower ends opening into the headers 88 To these headers 8 -8 are connected the pipes 1212 leading outward through the casing 1 and connecting to the pipe 11*.

It will be seen that in this form also the flow of the steam through the serpentine coils 6 is comparatively very rapid while the flow through the bifurcated elements 15-15 is comparatively very slow, the steam being substantially stagnant in these units. The dimensions of the several portions of the apparatus are here also so computed that the heating steam arrives in the headers 1414 in a saturated condition and that it is all condensed by the time the steam reaches the headers 8-8.

Obviously the apparatus can be modified in various further ways without departing from its spirit.

I claim:

1. In apparatus of the class described,the com ination of a shell, an inlet to and an outlet from said shell, whereby steam to be superheated may be circulated through the shell, a conduit extending through but not opening into the shell, means to supply superheated steam of higher pressure than the steam flowing through theshell to the inlet of the conduit, and means to remove condensate from its outlet, the conformation of said conduit being such at adjacent to its inlet the steam it is rapid while further on the steam is substantially stagnant.

2. In apparatus of the glass described, the combination of a conduit, means to supply superheated steam to its inlet, means whereby a heat absorbing fluid may be brought into contact with said conduit} and means to remove condensate from its outlet, the conduit being of such conformation that, for a .to cause a heat absorbing fluid to flow in contact with the outside of the conduit, the rela tive proportions of the two portions of the conduit being such that, for a given set of initial temperature and pressure conditions of the steam, and of the heat absorbing fluid the steam enters the second portion in a substantially saturated condition.

4. Apparatus in accordance with claim 8, the relative proportions further being such that the steam is all condensed by the time it reaches the outlet.

5. In apparatus of the class described, the combination of a horizontal header, a plu- 'rality of alined tubes opening from it and extending vertically upward, the upper ends of said tubes being closed, a serpentine coil above and in the plane of said tubes, and

- means placing the lower end of said coil into communication with the header.

6. Apparatus comprising in combination a plurality of structures as claimed in claim 5, said structures being arranged side by side, a shell enclosing said structures, means to supply superheated steam to said coils, means to remove condensate from said headers, and means to cause low pressure steam to flow through said shell in contact with said structures.

7. In apparatus of the class described, the combination of a plurality of similar conduits, means to deliver superheated steam to their inlets, means to remove condensate from their outlets, the conformation of each conduit being such that through the first portion of its length the steam flow is rapid while in the, remaining portion the steam is sub- 1 stantially stagnant, the portions of each conduit being in a single plane and the several conduits being arranged side by side, a shell enclosing said conduits, and means to cause steam'of a lower pressure than that in the conduits to flow through the shell in contact with said conduits.

8. The method of desuperheating and condensing steam comprising the steps of cooling it to its saturation point by causing it to flow at a relativelhigh velocity through a onduit surrounded by a heat abstracting medium, and then condensing it while it is sub stantially stagnant.

9, The method of desuperheating and conanaemia (lensing superheated steam of relatively high pressure while superheating steam of lower :pressure,compris1ng the steps of causinfihe su erheated steam to flow at relatively 'gh ve ocity in heat transferring relation to but out of contact with the low pressure steam' untilthe superheat is given up, and thereafter to-keep the two steams in such heat transferring relation with the high-pressure 10 steam substantially stagnant until .it is cen densed.

ANDRE HUET.

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