US1725399A - Apparatus for superheating steam - Google Patents

Description

8- 1929- w. D. LA MONT ET AL 1,725,399

- APPARATUS FOR SUPERHEATING STEAM Filed July 1927 2 Sheets-Sheet 1 INVENTORS MA 75,? fiOl/LfiI l/f/vflNT ALFRED FfR/Vsr 5y M ATTORNEYS Aug. 20, 1929. w. D. LA MONT ET AL 1,725,399

APPARATUS FOR SUPERHEATING STEAM Filed July 7, 192'? 2 Sheets-Sheet 2 INVENTORS MA 752 0006; A5 l/l/fa/vros ALF/e50 F f/Q/var ATTORNEYS Patented Aug. 20, 1929.

UNITED STATES.

PATENT" OFF-ICE.

WALTER DOUGLAS LA MONT, OF LARGHMONT, NEW YORK, AND ALFRED I. ERNST, OF PASSAIC, NEW JERSEY, ASSIGNORS TO LA MONT CORPORATION, OF NEW YORK,

N. Y., A CORPORATION OF NEW YORK.

APPARATUS IOB SUPERHEATING STEAM.

Application fled July 7,

This invention relates to the superheating of steam and to superheater and steam generating apparatus.

The operation of superheaters presents a considerable problem in heat transfer and V in protection of the material of the heater elements, owing to the fact that the flow of steam through the superheater is far from constant. Su erheaters consisting of headers or manifol s connected by a series of heating tubes or elements present advantages in' construction and placement, but it is difiicult to provide for uniform flow through the difierent tubes, as there is a l tendency for some of the tubes to present a shorter path or one of lower resistance to carry the greater portion of the steam.

This is undesirable, first because the heating surface in the tubes which get little or no steam flow is practically wasted, and also because the tubes with low steam flow tend to get very hot, and in some cases may be in danger of burning out.

It is an object of the present invention to provide superheater construction which permits a desired uniformity of steam flow through all of the heater elements or tubes. It is a. further object of the invention in its more specific aspects to provide a superheater structure which can be varied with different operating conditions, and also a structure which may be used for steam generation as well as for superheating.

According to the present invention, the flow of steam into or out of the heating tubes or elements is sufiiciently restricted so that a pressure is created in the intake manifold or header sufficient to provide a positive distribution and flow through the several elements of the superheater with varying steam outputs. The restrictions may be in connection with the intake ends of the tubes or elements or with the output ends thereof. In eithencase sufficient back pressure is produced, to assure desired distribution.

It is desirable. in some installations to rovide a construction which can be utilized for the superheating of steam or for the generating of steam by the formation of water .films on the inside of the heating tubes. These conditions require restrictions or orifices at the intake ends of the tubes of 1927. Serial No. 203,904.

quite diflerent magnitudes. Where steam'is to be generated a comparatively small orifice 1s required, whereas when the device is to be used as a superheater a relativel orifice is usually desirable. Whi e in its broader aspects the-invention is not limited to a superheater construction which can be adjusted for use as a superheater or as a steam generator, in itsmore s ific aspects such a construction is contemp ated and consists in a movable tube, which may for example be concentric with an intake manifold or header and fit in the inside thereof provided with one or two orifices. orifices are provided one may be of size suitable for the passage of water when the unit is to be used as a generatin unit and the other may be of correct size fiir steam when the unit is to be used as Suitable locking means may holding the orifice tube in the correct position and, of course, more than one size of orifice may be provided. 'The inner tube may be moved in any suitable manner to bring various orifices into register with the element, but preferably the tube is arranged to rotate within the manifold.

it somewhat different apparatus for obtaming the same control consists in an inner concentric orifice tube with an orifice of sufiicient size to be suitable for superheater demands. By partly rotating the tube, a portion only of the orifice may communicate )Wlth the tube, thus providing a very gradual and accurate control. Other equivalent arrangements of orifice tubes may of course be used, and are included in this feature of the Invention.

The invention'will be described in greater detail in connection with the drawings, in which Fig. 1 is a side elevation, partly in section, of a superheater unit according to the present invention;

Fig. 2 is a cross-section through a modified dwign;

Figs. 3 and 4 are sections and orifice tubes of orifices;

Figs. 5 and 6 are sections similar to Fig. 3, through a header and orifice tube provided with a single orifice.

through a header provided with a plurality larger When two i a superheater. be provided for In the construction shown in Fig. 1, an upper header 2 and a lower header 3' are connected by heating tubes or elements 1. The

upper header is provided with an orifice tube 4 containing orifices 5 registering with the tops of the heating tubes 1, and of a size such as to provide sufiicient'back pressure in the manifold or header tube to assure a predetermined distributed steam flow through all the elements.

In the construction shown in Fig. 2, the.

upper header or manifold 2 is shown without an orifice, and the lower header 3 is provided with an orifice tube 6 containing orifices 7 registering with the lower ends of the tubes 1 and serving to create sufiicient back pressure in the tubes themselves and in the manifold 2 to provide for asatisfactory. distribution of steam flowing therethrough.

In the foregoing descrlption emphasis has been laid on the possibility of providing uniform flow by means of suitable orifices or restrictions creating suflicient'back pressure to assure'that some steam flows into all the tubes. In many, if not in most superheaters,

a uniform flow of steam through all of the ent controlled non-uniform distributions may. be desirable. In its essence, therefore, the present invention may be considered as providing a positive method for assuring a predetermined distribution of steam through the tubes, and. isjnot limited to an arrangement which produces a uniform flow, this being only one, although perhaps the mostimportant distribution which can be effected by means of the resent invention.

' It is frequent y desirable to standardize superheater constructions, and in order to provide a standard construction which is applicable to superheaters with various aver-' age steam flows, or which may be used interchangeably for superheater construction and for generator tubes of the types described in La Mont patent, No. 1,545,668, patented July 14, 1925 and La Mont application serial No. 32,064, led May 22, 1925, it is necessary to provide for varying sizes of orifices, and this may be effected in various ways.

In the construction shown in Figs. 3 and 4, the upper manifold or header 2 is provided with an orifice tube 8 in which are two orifices 9 and 10 of different sizes. By vary ing the position of the tube 8 in the header,

either size orifice may be caused to register with the upper end of the tubes 1. In order to hold the tube 8 in a given position it may advantageously be provided with a pin or stud 11 which fits into corresponding grooves 12 or 13 in the header 2. In Fig. 3, the pin or stud is shown in groove 12 in order to bring orifice 10 in registry with the tube. If it is desired to cause orifice 9 to register with the tube, the tube 8 is turned through a quarter circle so that the stud or pin 11 is permitted to slide into the groove 13. Preferably the grooves extend only a short way into the header 2, as is shown in Fig. 4, so that it is only necessary to-withdraw the orifice tube a short distance in order to turn it.

Instead of providing a plurality of orifices of different sizes as shown in the construction of Figs. 3 and 4, an orifice tube 14 provided with a single orifice 15 of maximum size may be used, as is shown in the construction in Figs. 5 and 6. By suitably turning this tube a greater or less extent of the orifice 15 may be brought into registry with the tube 1, and this makes possible a gradual continuous variation of orifice size.

When a relatively small orifice is required for use in generators, the tube 14 is turned until only a small portion of the orifice l5 registers with the tube 1, as shown in Fig. 5. This construction not only provides for an orifice of suitably-small size but also directs the stream of water against the sides of the tubes, which aids in filni formation. A similar result can of course be obtained in the constructions shown in Figs. 3 and 4 by cutting the orifice 10 at an angle. Other means for providing suitable orifices or restrictions may be used.

In the foregoing description of the preferred embodiment of the invention separate orifices have been shown, and particularly orifices in orifice tubes. The invention of course is, however, not limited to this method of obtaining uniform distribu tion. The essential conditions'are that the resistance of flow into or through the tubes or into the exhaust header should be sufiiciently greater than the resistance of flow.

into and through the intake manifold so that a back pressure is produced therein. With many ordinary sizes of tubes this necessitates a special orifice structure. It should be understood, however, that if the area of aperture of all of the tubes is sufficiently small in comparison with the intake manifold, the tubes themselves will act as orifices and the provision of tubes small enough to produce uniform or any desired predetermined positive disposition of flow is included in the present invention.

Having thus described our invention, what is claimed as new is 1. A heater unit, comprising in combination an intake manifold, an exhaust manifold, tubular heating elements connecting the two, a concentric rotatable liner in the intake manifold provided with at least two series of orifices of diflerent sizes and ada ttions bringing any row of orifices into regised by its rotation to bring into register w1th ter with the tube ends.

the tube ends orifice apertures of varying Signed at New York, New York, this 5th 10 sizes. day ofJuly, 1927.

2. A heater unit according to claim 1, in which the orifice liner is provided with WALTER DOUGLAS LA MONT.

means for locking the orifice liner in posi- ALFRED F. ERNST.

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