Steam heaters

July 11, 1961

2,991,978

W. C. JONES

STEAM HEATERS

Filed July 29, 1959

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United States Patent Office

2,991,978

Patented July 11, 1961

2,991,978 STEAM HEATERS

William €. Jones, Medford, Mass., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania

Filed July 29,1959, Ser. No. 830,312 4 Claims. (Cl. 257—45)

This invention relates to steam heaters and has as objects to improve the efficiency of and the heat distribution of such heaters.

So-called non-freeze heaters, such as the one disclosed in U.S. Patent No. 1,847,608, use concentric inner and outer tubes. Steam is supplied into the inner tubes which are perforated and which discharge the steam through the perforations into the outer tubes. This invention is an improved form of such a heater in which improved means is provided for removal of the water condensed from the steam in the inner and outer tubes.

This invention will now be described with reference to the annexed drawings, of which:

FIG. 1 is a side view in section of one embodiment of this invention in which the heating tubes are pitched slightly from the horizontal, and

FIG. 2 is a side section of another embodiment of this invention in which the heating tubes are vertical.

Referring first to FIG. 1, an inlet header 10 has an outer, vertically extending wall 11 with a steam inlet connection 12. The header has a vertically extending inner wall 13 through which extend the inner, steam entering ends of steam distributing tubes 14. The other ends of the tubes &gt;14 extend through inner wall 15 of vent header 16. The header 16 has an air vent connection 17 which may discharge to atmosphere or to a condensate return fine. The outer ends of outer tubes 20 extend through the wall 15 but are closed except to permit the outer ends of the inner tubes 14 to pass therethrough into the vent header 16, so that the outer tubes 20 do not communicate with the vent header 16. The inner, distributing tubes 14 have small, spaced-apart openings 18 therein which discharge steam into the concentric, outer tubes 20.

The heater has an inner wall 21 spaced inwardly from the header inner wall 13, a vertically extending, condensate passage 22 being provided between the walls 13 and 21. The inner ends of the outer tubes 20 extend through the wall 21 so as to discharge condensate into the passage 22. Below the inlet header 10 and the condensate passage 22 is a condensate chamber 24 into which the passage 22 drains. The lower end of the inner wall 13 of the inlet header 10 is connected above the chamber 24 to the outer wall 11 of the header 10 by a bottom wall 25 which slopes upwardly from the bottom of the wall 13 so as to permit the bottom distributing tube 14 to extend through the wall 13 without having to extend the inlet header lower than is shown by FIG. 1. An outlet connection 26 in the wall 11 is opposite and opens into the condensate chamber 24.

The outer tubes 20 are pitched so that their outer ends are slightly higher than their inner ends for facilitating the drainage of condensate therefrom into the condensate passage 22. The outer tubes 20 have closely spaced, plate-type, entended surface fins 30 around and in contact with their outer surfaces.

Below and spaced from the bottom tube 20, and extending parallel thereto, is a correspondingly pitched condensate drainage tube 32, the outer end of which communicates through the wall 15 with the vent header 16, and the inner end of which communicates through the wall 21 with the condensate chamber 24.

There may be a single row of tubes 20, of there may be another row or rows behind the row shown.

In the operation of FIG. 1, steam supplied through the inlet connection 12 passes through the inlet header 10 into the inner ends of the distributing tubes 14. The steam is distributed by the tubes 14 through the openings 18 into the outer tubes 20. Non-condensible gases such as air pass out the outer ends of the tubes 14 into the vent header 16, and from the latter, through the vent connection 17 to disposal. Water condensing in the inner tubes 14 is carried out with the vented air into the vent header 16, and is conveyed through the drain tube 32 into the condensate chamber 24.

The condensate resulting from the condensing of the steam in the outer tubes 20 is drained through the inner ends of the latter into the condensate chamber 24. The condensate in the chamber 24 passes out through the outlet connection 26 to a return line.

FIG. 2 shows a heater in which the distributing tubes and the air heating tubes extend vertically. A horizontally extending inlet header 40 has a bottom wall 41 with a steam inlet connection 42. The header 40 has an inner wall 43 above and spaced from the wall 41, and through which extend the bottom, steam entering ends of steam distributing tubes 44. The other ends of the tubes 44 extend through lower wall 45 of horizontally extending vent header 46 at the top of the heater. The vent header 46 has an air vent connection 47. The upper ends of outer, air heating tubes 50 extend through the wall 45 but are closed except to permit the upper ends of the steam distributing tubes 44 to pass therethrough into the vent header 46, so that the outer tubes do not communicate with the vent header. The distributing tubes 44 have small, spaced-apart openings 48 therein which discharge steam into the outer tubes 50 which are concentric with the tubes 44.

The heater of FIG. 2 has a wall 51 above and spaced from the wall 43, a horizontally extending, condensate passage 52 being provided between the walls 43 and 51. The lower ends of the outer tubes 50 extend through the wall 51 so as to discharge condensate into the passage 52. The condensate passage 52 is closed at one end by header wall 57, and its other end discharges into condensate chamber 54 which extends over outlet connection 56. The header wall 57 also extends across one end of the inlet header 40, across the other end of which, at the condensate chamber 54, a header wall 55 extends. The wall 55 is sloped from where it joins the lower wall 41, into the condensate chamber 54 to where it joins the wall 43. This permits the end distributing tube at that end of the heater to extend through the wall 43 without having to extend the inlet header 40 further to the right than is shown by FIG. 2.

To the right of the end outer tube 50 at the right end of the heater is a condensate drain tube 62, the upper end of which opens into the vent header 46, and the lower end of which opens into the condensate chamber 54.

Extended surface fins 60 extend around and in contact with the exterior surfaces of the heating tubes 50 and the drain tube 62.

In the operation of FIG. 2, steam supplied through the inlet connection 42 passes through the inlet header 40 into tile lower ends of the distributing tubes 44. The steam is-distributed by the tubes 44 through the openings 48 into the outer tubes 50. Non-condensible gases such as air pass out the upper ends of the tubes 44 into the vent header 46, and from the latter, through the vent connection 47 to disposal. Water condensing in the distributing tubes 44 is carried out with the vented air into the vent header 46, and is drained from the latter through the drain tube 62 into the condensate chamber 54.

The condensate resulting from the condensing of the steam in the outer tubes 50 is drained through the lower

2,991,978 ends of the latter into the condensate passage 52, and drains from the latter into the condensate chamber 54. The condensate in the chamber 54 passes out through the outlet connection 56 to a return line.

In the embodiment of FIG. 1, the drain tube 32 has 5 the same diameter as the outer tubes 20, extends parallel to the parallel tubes 20, and is spaced the same distance from the adjacent tube 20 as the tubes 20 are spaced apart. The fins 30 extend around the drain tube 32. This permits a reduction in cost since the usual machine for punching equally spaced, tube receiving holes in the fin stock, can be used. This same reason applies for having the drain tube 62 of FIG. 2 extend parallel to the heating tubes 50, and spaced the same distance from the adjacent tube 50 that the tubes 50 are equally spaced. The water in the drain tubes is hot and adds heat to the fins for transfer to the air to be heated.