US1931994A - Locomotive superheater boiler - Google Patents

Description

R. M. OSTERMANN LOCOMOTIVE SUPERHEATER BOILER Oct. 24,

Filed Nov 4 1930 lIi O ct. 24, 1933. R. M. osTERMANN LOCOMOTIVE SUPERHEATER BOILER Filed- Nov. 4, 1930 2 Sheets-Sheet 2 INVENTOR fiudolphfl. Osfrml) BY FVI w ATTORNEY Patented Oct. 24, 1933 UNITED sTATEs PATENT OFFICE to The Superheater Company,

New York,

Application November 4, 1930. Serial No. 493,335

3 Claims.

ed only by contact with the furnace gases.Y

While this principle applies obviously to locomotives as well as to stationary plants, difliculties have been encountered in its application in the locomotive field, so that, in practice almost without exception, the steam for locomotive engines is superheated in units heated solely by gas contact.

I have found, however, that the radiant type superheater may be used satisfactorily in the fire box of a locomotive, or in'a similar -water cooled fire-box, by placing it out of the direct line of fiow of the gases passing out of the fire-box and at the same time shading the superheater somewhat from the radiation. I

The novel features of my invention are pointed out with particularity in the appended claims. In order that my invention may be fully and clearly understood, however, I will now describe in detail, in connection with the accom-panying drawings, a superheater installation serving as an illustrative'embodiment of my invention. In said drawings,

Fig. 1 taa/longitudinal central section through the center of a locomotive having a radiant type superheater installed therein in accordance with my invention, and

Fig. 2 is a transverse vertical section taken through the fire box of the locomotive shown in Fig. 1.

In the locomotive illustrated in the drawings, 10 is a boiler shell having a steam space 12 and a fire-box 14. Fire-box 14 has the lusual watercooled side walls 16, 16 extending longitudinally of the boiler and arranged substantially Vertical. In accordance with my invention, a radiant type superheater has its elements 18, 18 arranged in the fire-box 14 closely adjacent to one or both of the side walls 16. The elements 18 are thereby out of the direct line of fiow of the gases from the fire-box to the smoke fiues of the locomotive, the most of which flow through the central portion of the fire-box. In order, however, to shade the elements 18 somewhat from the direct r'adiation of the burning -fuel I place between each group of elements 18 and the center of the furnace 14 an apertured water-cooled structure 20. As illustrated, there are two water-cooled structures 20, and each is built up of a plurality of curved water tubes 22, 22 which extend from Vertical headers 24, 24 to the crown sheet 26 of the locomotive. The headers 24 connect at their lower ends with the throat 28 of the locomotive at the points 30, 30. The tubes 22 are set far enough apart so that a material amount of radiation passes between them to strike the elements 18. It will be clear further that the structures such as 20, being exposed to the radiation and to the hot gases in the fire box, generate a great deal of steam and thereby add to the capacity of the boiler. Moreover, the circulation in the tubes 22 of structure 20, being from the headers 24 up to the crown sheet 26, carries a greater amount of water to the upper surface of the crown sheet than would otherwise reach this point in the boiler and thereby protects the crown sheet from over-heating. It will be obvious that, while the structures 20 are particularly adapted for use in connection with superheater elements in the fire 'box they may be used without such superheater and, in such case, one may be placed in the center of the fire-box.

It Will be seen that the superheater elements 18 are close to the water cooled sides of the firebox and that there is nothing between such elements and the fire-box -wall to hinder radiation from one to the other. Therefore, when elements 18 have attained a temperature materially above that of the water in the locomotive boiler, they begin to radiate to one of the fire-box walls 16. As the heat radiated away from a body varies as theA difference between the fourth powers of the absolute temperatures of itself and the radiation receiving body, the net amount of heat absorbed by the elements is greatly reduced when they are delivering steam above the safe temperature of 750 F., thereby permitting the elements to expose a large surface to radiant heat on their furnace sides to give them high capacity without the danger of overheating. Furthermore, the shading structure 20 has its tubes 22 arranged largely transversely to the tubes of elements 18, so that only relatively short sections of the superheating tubes are exposed to radiant heat and the Sections of the superheater tubes intermediate to those exposed are further protected by counter radiation on their furnace sides to the structure 20. Any excess heat in the metal of the tubes of elements 18 therefore does not have to travel any material distance along such tubes before being absorbed by cooler metal of the shaded sections or dissipated by radiation and the temperature gradient along the tubes of the elements and, therefore, the maximum temperatures are maintained within safe limits in spite of 'the closeness of the elements 18 to the combustion zone.

In case the proportions of the fire-box are such that it is inconvenient to shade the elements 18 to the extent desired by means of apertured watercooled structures, baifles 32, 32 (Fig. 2) may be used in addition to the water-cooled structures for this purpose.

steam for the elements 18 is preferably conducted from the forward end of the dry pipe 34 to the fire-box.

I n the arrangement shown, the forward end of dry pipe 34 connects to a header structure 36 to which are connected the elements 38, 38 of an ordinary convection type superheater contained in smoke tubes 40, 40 in the boiler 10. The inlet ends of the elements 38 connect to the structure 36 at points 42, 42 and the outlet ends of the elements 38 connect to the structure 36 at points, not shown, in a manner analogous to that shown at points 42. From the outlet ends of elements 38 the steam passes into chambers (not shown) separated from the inlet ends of elements 38 and thence in known manner by an arrangement not shown into the chamber 44. From chamber 44 steam passes by pipes 46 downwardly through the smoke box 48 and through the tubes 50, 50 which run longitudinally through the water space of boiler 10 into the forward portion of flre box 14.

The rear ends of pipes 50 connect to the pipes 52,

52 which extend rearwardly in the lower side portions of the fire box 14 parallel to the longitudinal side walls thereof and whichserve as headers for the inlet ends of the U-shaped superheater elements 18. The outlet ends of the elements 18 are connected to headers 54, 54 which are shown as parallel to headers 52 and below and somewhat on the inside thereof. In order that steam may be distributed through the elements 18 at a uniform rate, the outlets of the headers 54 are placed at the rear ends thereof, thereby obtaining an anti-parallel flow through the elements whereby equal flow resistance is ensured through all the units 18 from inlet header 52 to vOutlet headers 54. The headers 54 are connected by return bends 56 with return pipes 58 which The locomotive boiler 10 is shown as having the usual dry pipe 34 and the connect at their forward ends with the rear ends of tubes 59 which run from the front portion of the fire-box 14 through the water space of the boiler 10 and connect to the cylinders (not shown) of the locomotive.

Throttle means for controlling the flow of steam to the superheating elements 38 and 18 may be placed wherever desired. At present, the two most common locations for the throttle means are either at 60 in the steam' dome 62 of the locomotive or else in the chamber 44 adjacent the outlet ends of the convection heated superheater elements.

It will be understood that I have described herein above only one embodiment of my invention and that it may be used in stationary boilers when desired as well as in locomotives. It will be understood also-that parts of my invention may be used apart from the others without avoiding certain of my claims.

Iclaim:

1. The combination with a locomotive type boiler, of a narrow header having its lower end connected to the throat of the boiler and extending upwardly in the fire box, and a series of spaced curved tubes arranged substantially in the same Vertical plane as said header and connected into said header and into the crown sheet of the firebox.

2. The combination of a steam boiler having a fire box having water cooled side walls, superheater elements arranged close to said walls and so as to radiate thereto without obtruction, and water cooled means for only partially shading said elements from direct radiation originating in the central portion of said box, said means for partially shading the elements having apertures therein extending largely transversely to the tubes of the superheater elements.

3. The combination with a horizontal fire-tube boiler having an internal fire-box provided with water-cooled side walls, superheater elements arranged close to one of said walls and so as to radiate to such wall without obstruction, and means for only partially shading said elements from radiation originating in the central portion of said box, said means comprising a narrow header having its lower end connected to the fire-box tube sheet of the boiler below the fire tubes and extending upwardly in the fire-box, and a series of spaced water tubes arranged substantially in the same Vertical plane as said header and connected into said header and also into the crown Sheet of the fire-box.

' RUDOLF M. OSTERMANN.

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