US1773054A - Method and apparatus for the treatment of steam - Google Patents

Description

Aug. 12, 1930. J. R. McDERMET 1,773,054

METHOD AND APPARATUS FOR THE TREATMENT OF STEAM Filed April 21, 1928 Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE JOHN B..MCDERMET, OF JEANNETTE, IENNSYLVANIA, ASSIGNOR TO ELLIOTT COMPANY, OF JEANNETTE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA METHOD AND APPARATUS FOR THE TREATMENT OF STEAM Application filed April 21,

The present invention relates broadly to the art of steam treatment, and more particularly to an improved method and apparatus by means of which either superheated or sat- 5 urated steam may be effectively treated to insure complete desuperheating in the case of superheated steam, and the separation of excess water in case of either superheated or saturated steam treatment.

It is well understood in the art to which the present invention relates that exhaust steam is becoming more and more highly superheated, and that such superheated steam has only a very small proportion of the conductivity of saturated steam from the standpoint of heater performance. This is necessarily true since the major transfer of heat in heater condensation is from the latent heat of the steam in condensing. Inasmuch as the specific heat of saturated steam is approximately .46 B. t. u. per pound while the latent heat is substantially 97 0 t. u. per pound under usual conditions of operation, the advantages of desuperheating will be apparent.

In the art of desuperheating, difiiculty arises in supplying the roper amount of water for insuring comp ete saturation of the steam and in maintaining any eflicient relationship between the quantity of water and the quantity of steam. Obvlously, if too little water is supplied, the steam is not completely desuperheated, and if too much water is supplied, not only is there a loss due to steam condensation, but objectionable results may follow from the presence of excess water. In accordance with the present invention, I provide an improved method of treating steam whereby the desired desuperheating is accomplished without the possibility of carrying over any excess water. I also provide a method and apparatus for treatment of either superheated or saturated steam and efiective for removing all excess water therefrom.

The present invention also provides a method and apparatus for the treatment of steam such that an intimate contact. between the steam and desu erheating water, where supplied, is obtaine and such that any excess water is removed.

1928. Serial No. 271,756.

In the accompanying drawings I have shown for purposes of illustration only, and in a more or less diagrammatic manner, a preferred embodiment of the present invention, it being understood that the drawings are for purposes of illustration only, and not for purposes of limitation.

In the drawings Figure 1 is a longitudinal sectional view through a portion of steam treating apparatus constructed in accordance with the present invention, and

Figure 2 is a top plan view of the same.

In accordance with the present invention, there may be provided a conduit 2 into which either superheated or saturated steam may be admitted in such manner that it will flow through the conduit in the general direction indicated by the arrow 3. Extending into the conduit on the up-stream side with respect to steam flow is a water jet or spray nozzle 4, herein shown as pointed lip-stream with respect to its discharge end 5, although the direction of discharge may be varied. The nozzle is connected to a suitable source of water through the pipe 6. This spray nozzle may be of any desired construction for spraying water into superheated steam passing through the conduit.

At a point in the conduit down-stream with respect to the spray nozzle is a perforated plate 7 of truncated cone shaped configuration, the base of the cone having a flange 8 which may conveniently be clamped between the flanges 9 on adjacent sections of the conduit. The smaller end 10 of the cone is freely open to permit the passage of steam therethrough and into a separating chamber 11. This chamber may be of any desired form, but is herein illustrated as provided with a series of vertically extending guides 12, adapted to form slides for guidmg a separator 13 into place therein. The separator is herein illustrated as comprising end plates 14, connected b a cross-plate 15 intersecting the path of ow of the steam The upper part 16 of the plate 15 is prefer" ably angularly disposed, as indicated more particularly in Figure 1 of the drawings, and provided with a downwardly and inwardly turned end 17 forming a trough or collecting reservoir 18 for the purpose hereinafter de scribed.

The separator above the end 17 provides a free passage between the end plates 14 for the steam in its travel to the outlet 19.

The separating chamber 11 at its lower portion may be formed with an opening 20 through which separated water may be drawn off to any desired point.

From the foregoing description, it will be apparent that in case of superheated steam, it enters from the right hand end of the conduit as viewed in the drawings and successively passes the nozz1e.4, the cone 7, and the separator 13. As it passes the nozzle it receives the water injected thereby in the form of a fine spray so that it passes on from the nozzle in the form of a mixture. It is this mixture which is acted upon by the cone and separator.

The sequence referred to is important, but it will be apparent that the distances and relative arrangement of the different parts may be considerably varied, the distance between the nozzle and the cone, for example,

being capable of an extremely wide variation,

and the distance between the cone and the separator being capable of a considerable variation. The particular construction of the cone, nozzle and separator may likewise be varied, as will be apparent from the following description.

In operation, the mixture leaving the nozzle comes to the large end of the cone which has a diameter D approximately e ual to the inside diameter of the conduit. T e area of the outlet end 10 of the cone is materially less, it having a much smaller diameter d.

This change in flow area presented by the cone necessarily accelerates the velocity of the mixture passing therethrough, and passes the mixture onward to the separator, through the conduit, in the form of a stream having a smaller cross-sectional area than the area of the conduit, and traveling at a higher velocity than the mixture intermediate the nozzle and the cone. This stream of high velocity mixture is in reality surrounded by an annulus composed of a steam and water mixture at the same pressure and tern erature of the high velocity stream, but di ercnt therefrom in that it is relatively quiescent.

In passing throu h the cone, the mixture is necessarily compel ed to impinge thereon in such manner that part of it passes through the perforations in the cone and forms the relatively quiescent annulus referred to, while the remainder is concentrated through the open end, and forms the high velocit stream.

The restriction in the area 0 the cone and the increased velocity referred to impose a pressure drop through the cone which is effective for forcing steam and entrained wateroutwardly through the perforations, this action resulting in a series of relatively small jets extending radially of the cone and substantially normal to the surface thereof. The water entrained in the steam over that portion of the area represented by the difference in the diameters D'and d is deposited upon the surface of the cone, and immediately projected into the quiescent area of the low velocity stream in the manner referred to.

The cone thus functions to collect the water suspended in what may be termed the outer annulus of the mixture, and disposes of it in either of two manners. The first of these may be considered as a redistribution of the water in part into the central stream of high velocity steam. Such redistribution is desirable since it accomplishes an intimate contact and further intermingling of the steam and water.

Secondly, such water may be projected mechanically, in the manner referred to, through the openings in the cone into a region of comparatively quiescent flow. In this manner, it enables any surplus water to precipitate or separate onto the conduit surface,-run down into the bottom thereof, and thence into the separator and out of the opening 20. These actions directly take place as the result of the construction of the cone. It also functions, as set forth, to provide a high velocity stream and a low velocity annulus, which enables any surplus water deposited from the fast moving stream to automatically arrive in the slow moving annulus, giving it a further chance to separate and run into the separator.

The construction possesses a further advantage in that it enables a separator of relatively smaller size to be utilized, the separator having imposed thereon a much easier separating duty in terms of quantity than would be the case under different conditions of operation. This will be appreciated when it is considered that the separator, due to the concentration of the major portion of the water in the high velocity central stream, has to operate over a much smaller area than would be the case if the entire area of the conduit were filled with a uniform mixture.

Since the stream carrying the water in suspension is of much less area than the inside diameter of the conduit, thecapacity of the separator in terms of conduit area is substantially increased. Thus, a relatively small separator may take care of the flow through a relatively large conduit.

In'addition to the above, regardless of the construction of the separator, it necessarily has impinging thereon two streams moving velocity.

tor herein disclosed further contributes toward. the attainment of the desired result of uniform water distribution within-the entire mass of steam, together with the separation of any surplus moisture.

This is true for the reason that the water thrown at high velocity against the Separator travels upwardly into the trough 18, out of the path of the steam, while the steam is permitted to flow upwardly around the trough to the outlet 19. Any slower moving water content impinging against the separator may flow downwardly directly into the bottom ol the separating chamber.

The apparatus hereinbefore described functions in the manner set forth whensaturated steam is being treated for the se aration of excess water, it being understoo that in such cases the discharge nozzle is not utilized.

It will be apparent to those skilled in the art that the present method and apparatus enables large quantities of steam to be ell'ectirely treated without any undue restriction to the low thereof, the conditions of treatment being such that the entire body of steam is given ample Opportunity for contact with water under such conditions as to effect an intimate and uniform intermixing thereof for purposes of destroying the superheat. and under such conditions, that free or surplus water is not carried over into the outlet 19 and thence to other'a-pparatus' in which the dcsuperheated steam is to be utilized.

" Changes, as herein referred to, may be made in the construction and operation of the apparatus without departing from the SpH'lt of my invention or the scope of my broader claims. v

' I claim:-

' 1. Steam treatment apparatus, comprising a steam conduit, means for'supplying water thereto, a separator for surplus water, and means intermediate the point'of water supply and separator for producing side by side flow zones having different velocity characteristics, o

2. Steam treatment apfparatus, comprising a steam conduit, means or supplying water tl ereto, a separator for surplus water, an means intermediate the point of water supply and separator for producing *aflow zone of high velocity, and 1f flow zone substantially.

concentric thereto and of relatively lower 3. Steam treatment apparatus, compris-,

'- ing a steam conduit, means for supplying water thereto, a separator for surplus water, and means intermediate the point of water supply and separator for producing a flow zone of highv velocity. and a flow zone of rela-,

tively lower velocity, with the higher velocity zone within the lower velocity zone.

4.Stea-m treatment apparatus, comprising a conduit for steam, a water supply means in the upstream end of said conduit, a separator in the downstream end of said conduit, and a velocity increasing means at an intermediate noint in said conduit, said velocity increasing means being constructed and arranged for increasing the velocity of a part only of the flow through the conduit.

5. Steam treatment apparatus, comprising a conduit for steam, a water supply means in the up-streamend of said conduit, a separator in the down-stream end of said conduit,

separator a steam and water mixture comprising zones traveling at different velocities, said zones being delivered to said separator simultaneously.

7. Steanrtreatment apparatus, comprising a separator, and means for delivering to said separator a steam and water mixture comprising zones traveling at diflerent velocities, with the high velocity zone within the lower velocity zone, said zones being delivered to said separator simultaneously.

8. In the method of treating steam, the steps comprising suppl ing-water thereto, increasing the velocity 0% a portion only thereof, and subjecting the steam and water mixture at high velocity to the action of a, separator.

9. In the method of treating superheated steam, the steps comprising supplying dc-- water .from the high velocity stream into the low velocity stream, and causing both said streams to impinge against a separator.

11. In the method of treating superheated steam, the steps comprising supplying desuperheating water thereto, effecting a radial movement 7 of water outwardly from the inner steam and'water mixture zone intoan outer zone containing steam, and'thereafter subjecting-the entire mixture including both zones to the action ofaseparator.

12. Separating apparatus, comprising aconduit, a water supply means in the up stream end of said conduit, a se arato'r 1n the down stream end of said con uit ,and a 7 locity, completely confinin 1 irg substantially point intermediate said water supply and separator and effective for increasing the velocit of a part only of the flow through the con uit. U

13. Treatment apparatus, comprising a conduit, means for supplying water thereto, a separator for surplus water, and means intermediate the point of water supply and separator for producing overlapping substantially parallel flow zones having different velocity characteristics.

- 14. Treatment apparatus, comprising a conduit, means for supplying Water thereto, a

separator for surplus Water, and perforated means intermediate the point of water supply and separator for producing overlaparallel flow zones having i erent velocity characteristics.

15. In the method of treating steam, the steps comprising delivering water thereto, transforming the resulting mixture into a zone of high velocity and a zone of low veboth zones and insuring continued travel t ereof, and cansing both said high and low velocity zones to im inge against a separator.

11 testimony whereof I have hereunto set my hand.

JOHN R. McDERMET.

Images