US2532208A - Locomotive draft chamber - Google Patents

Description

OV- 1950 J. G. VALLELY 2,532,203

LOCOMOTIVE DRAFT CHAMBER Filed Sept. 4, 1946 3 Sheets-Sheet 1 Nov. 28, 1950 J. G. VALLELY LOCOMOTIVE DRAFT CHAMBER 5 Sheets-Sheet 2 Filed Sept. 4, 1946 5 Sheets-Sheet 5 Nov. 28, 1950 J. G. VALLELY LOCOMOTIVE DR'AFT CHAMBER Filed Sept. 4, 1946 00 0O 00 00 0O 0O 00 O0 00 JOSEPH G. V/Q'L LELY Patented Nov. 28, 1950 UNITED STATES PATENT OFFICE LOOOMOTIVE DRAFT CHAMBER Joseph G. Vallely, DuBois, Pa,

Application September 4, 1946, Serial No. 694,789

3 Claims.

The present invention relates to improvements in steam engines and more particularly pertains to the front end structure of locomotives which provides an improved draft chamber promoting a self-cleaning action of the flue tubes and the smoke box and accordingly promoting improved generation of steam in the boiler.

The front end structure of most locomotives in the past has been designed along the principles of the front end developed by the American Railway Master Mechanics Association. Such a front end structure includes an impervious table plate extending forwardly from the lower end of a substantially impervious vertical header plate. This table plate terminates short of the front end of the locomotive boiler shell and a wire netting spark arrester extends angularly upward from the forward end of the table plate to the top portion of the boiler housing. Such a structure provides that a large percentage of the exhaust gases from the flue tubes must pass downwardly by reason of the header plate and then pass under the table plate and forwardly thereunder and escape through the openings in the angularly disposed spark arrester before pas sing out through the smoke stack. This relatively long and tortuous path which the exhaust gases must follow causes the movement of these gases to be impaired and accordingly does not move all of the cinders out of the fines, and provides for deposits of cinders in the smoke box below the table plate, on top of the table plate and in the flue tubes. Further trouble is sometimes encountered with accumulations of cinders on. the top of the firebox arch. These deposits of cinders in the Master Mechanics front end. draft chamber and in the other places designated, interfere with the movement of the exhaust gases through the flue tubes and often cause these fines to clog to such an extent as to materially interfere with the steam generating characteristics of the boiler. The Master Mechanics front end assembly accordingly requires frequent cleaning of the flue tubes and frequent removal of large quantities of cinders from the front end structure below the table plate, on top of the table plate and adjacent the front door, and in some cases from the top of the firebox arch.

The angularly disposed spark arrester also interferes with free access to the draft chamber through the front end of the locomotive and blocks observation of the exhaust nozzle and other parts of the front end assembly.

This

spark; EII'EStGI." must also be removed before any repair. maybe made in this portion ofthe locomotive.

It is accordingly; an object of the present invention to provide a front structure for a locomotive wherein the disadvantageous features. of the Master'Mechanics design areavoided; and to provide a locomotive draft" chamber which will materially improve the movement of gases and solids through theflue tubes and provide a selfcleaningassembly which will not only remove the cinders and deposits from the flue tubes, but which will promote: the removal of these solids from the smoke box itself through the smoke: stack, and. maintain the top of the fire box arch clean where this condition is not realized with the Master Mechanics type front end.

Another object of the invention is to: so proportion the escape of gases from the flue tubes around the exhaust nozzle as to provide a maximum utilization: of the jet characteristics of the exhaust nozzle. and? thereby promote an eificient discharge: of. the. exhaust gases and solids such as'cinders fromthe locomotive. fire box and flue tubes. A still furtherobject of the invention isto provide afront endstructure for a locomotive which may be readily inspected 'u'pon opening of the front end door of a locomotive.

Other objects and features of the invention will be more'apparent as the present disclosure proceeds and upon consideration of the accompanying drawings and the following detaiiled description wherein an exemplary embodiment of the invention is disclosed.

In the drawings:

Fig. 1 is a longitudinal sectional view of alocomotive front end assembly embodying the invention;

Fig. 2. is a transverse sectional view taken on the line. 2--2.of Fig. 1.; and

Fig. 3 isa sectional plan view of the table plate assembly and exhaust nozzle taken on the; line 3-3 of Fig. 1..

An advantageousfeature of the present invention pertains to the adaptation of front end structures within the boiler housing of a locomotive of types patterned in general along the lines of the Master Mechanics front end arrangement without materially altering the exist ing structural features thereof. The front end assembly characterizing the present invention may be. fitted Within the boiler housing adjacent the smoke stack after the conventional type.

Master Mechanics front end parts have been removed. Accordingly, the table plate forming part of the present invention may be arranged in the front end structure around the exhaust nozzle and the spark arrester netting likewise may be arranged in the smoke box without changing other parts of the locomotive.

The front end structure as hereinafter described in detail provides for marked improvements in the movement of gases and solids through the boiler flue tubes and some of the gases which pass through these fiues escape through the header plate and a portion of the gases escape through the table plate and the remainder of the gases escape through the spark arrester so as to substantially remove all of the cinders from the flue tubes and the smoke box. Accordingly, improved steam generating characteristics are provided. The flue tubes are maintained free of solids to promote improved heat transfer to boiler water and steam. The reduction of resistance in the passage between fire box and stack also contributes to the improved steam generating characteristics. The escape of some of the gases through the table plate also provides for more eificient utilization of the exhaust nozzle as means for moving gases out of the smoke box to further facilitate clearing the flues and improving the steam generating characteristics. Another advantage is gained by improving the exhaust through the smoke stack in that the exhaust nozzle need not be made so small as required in the past and the present invention thereby eliminates some of the back pressure on the cylinders of the locomotive since the exhaust nozzle has a larger cross sectional area and still provides for good jet action in drawing the exhaust gases from the flue tubes and the smoke box.

Referring to the drawings, there is shown in Fig. 1 a main boiler shell H] for a locomotive. The boiler extends forwardly beyond the flue sheet H. A substantially cylindrical housing 14 is mounted forwardly of the main boiler shell in so as to provide a smoke box or draft chamber l6 positioned wholly forward of the flue sheet I I.

The draft chamber I6 is closed at the forward end in the usual manner by a disc-shaped member I! which is preferably bolted to the cylindrical housing I l so as to be readily removable therefrom. The end member I! is provided with a conventional type front end door 18. This door ma be mounted for hinged movement in a conventional manner so as to be readily opened for inspecting the interior of the front end assembly or draft chamber.

The invention is adaptable to a locomotive having a conventional type fire tube super-heater. Such a super-heater includes heating units l9 extending into the boiler flues 2| and receiving steam from a dry pipe (not shown) and which is adapted to be connected to the heater inlet 22. The steam after being distributed through the super-heater is discharged from the super-heater steam header 24 to the engine steam pipes 26 which lead to the locomotive cylinders. The engine exhaust pipe 21 is located in the usual position at the lower portion of the smoke box or draft chamber l6 and terminates preferably, although not necessarily, in a separate nozzle or tip 28 as shown in Fig. 1.

The housing I4 is provided with an opening 29 through which the locomotive smoke stack 3! extends. The smoke stack may be supported in any suitable manner so as to be substantially vertically aligned with the discharge opening of the exhaust nozzle 28. The lower end of the smoke stack 3| terminates above the exhaust nozzle 28 as shown particularly in Fig. 1 so as to provide a relatively large unobstructed area therebelow for gathering exhaust gases and the like for outward passage through the smoke stack.

A characteristic feature of the present invention pertains to the table plate which is designated at 33 in the drawings. This plate 33 is arranged in a substantially horizontal manner and may be supported on the inner walls of the housing [4 by means of brackets shown at 34. The table plate 33 extends transversely across the housing I l a slight distance below the axis of the boiler and ma be in alignment with lower edge of the opening which is normally closed by the front door [8. The table plate 33 is fitted around the exhaust nozzle 28 as shown in Fig. 3. The table plate 33 is formed of sheet metal having apertures therein uniformly distributed over the area of the plate. The apertures 36 may be of any cross sectional shape and are preferably circular so as to act as small nozzles. In one type of locomotive'the table plate 33 is approximately sixty inches long and thirty inches Wide and includes one-quarter inch apertures or holes 36 distributed over the entire area of the plate and being spaced from each other at approximatel one inch from the center of one aperture to the center of the next adjacent aperture. The table plate 33 is joined to the header plate 31 in any suitable manner so as to provide an. impervious connection therebetween.

The header plate 31 extends vertically downward from the super-heater unit as shown in Fig. l. The header plate 31 is provided with a plurality of apertures 40 adjacent the upper end thereof and these apertues are closed by a plurality of netting arrangements as shown at 39 in Figs. 1 and 2. The netting 39 is substantially aligned with the upper row of boiler tubes 2| as shown in the drawings. The nettings 39 are so positioned that the connections to the heater units l9 to the super-heater header are exposed to view through these nettings. The nettings 39 are preferably located as near as possible to being in alignment with the top row of flue tubes 2|.

In contrast to the front end structure as designed by the American Railway Master Mechanics Association, the spark arrester in the present invention is arranged in a horizontal position and provides an extension of the table plate 33. The spark arrester designated generally at +2 is formed of wire netting suitably secured in position by means of clamping plates 43 and pins i t for attaching the netting to the table plate 33 and brackets 45. The front portion of the spark arrester 42 is supported by a member l? which extends upwardly from the lower portion of the cylindrical housing l4 and includes a horizontal flange 46 for maintaining the netting 52 in a proper position. The space between the spark arrester support 4-! and the front member I! may be filled with heat insulating material such as fibrous asbestos so as to prevent transmission of the heat of the exhaust gases to the front end member I! and to provide an air-tight structure at this portion of the locomotive.

The locomotive draft chamber includes a register plate 49 which extends downwardly at an angle from the forward end of the table plate 33 The register plate is provided with a movable portion for adjusting the aperture between the lower end of the register plate and the bottom wall of the housing [4.

The apertures in the table 33 and the openings in the netting forming the spark arrester 42 are so proportioned in size and distribution that approximately sixty percent of the exhaust gases pass through the spark arrester 42 and approximately thirty per cent of the exhaust gases pass through the apertures 36 in the table plate 33. The remaining ten per cent of the gases pass through the nettings 39 covering the openings 40 in the header plate 31. The size of the openings or apertures 35 in the table plate and the spacing thereof may be varied as long as this approximate ratio of gases passes through the holes in the table plate. The exhaust gases are accordingly substantially evenly distributed around the exhaust nozzle 28 so that the jet action thereof will provide for efficient movement of the exhaust gases into the smoke stack 3|. It will be observed that the exhaust gases which pass through the header plate 31 and the apertures in the table plate 33 are not compelled to complete a pronounced turn before escaping through the smoke stack as has been required in the front end design as devised by the American Railway Master Mechanics Association. The front end assembly herein described has been found in actual practice to provide a substantially self-cleaning draft chamber, which removes the disadvantage of removing the locomotive from operation to clean the cinders and the like from the flue tubes and the smoke box. The self-cleaning action is promoted by the apertures in the table plate and spark arrester and the openings in the header plate 31 provides sufficient draft to remove the cinder-s from the top group of flue tubes which have previously tended to clog and interfere with the draft of these flues.

The entire draft chamber constructed in accordance with the present invention is readily accessible by the removal of the front end member 11 and the condition of the flue tubes may likewise be observed through the openings 4|] in the header plate 31. Locomotives equipped with the front end of the present type have been found to be free steaming and require very little attention from a maintenance standpoint and substantially no interruption in operation for cleaning purposes.

While the invention has been described with reference to a particular type of loco-motive boiler structure, it is apparent that changes may be made in the structural features and the materials employed. Such modifications and others may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. A locomotive front end structure comprising, a housing forming a continuation of the locomotive boiler shell, a disc-shaped member closing the end of said housing, a door in said disc-shaped member, a smoke stack extending upwardly through the housing, an exhaust nozzle positioned below the smoke stack in vertical alignment therewith, a substantially horizontal table plate surrounding the exhaust nozzle and extending across said housing and positioned below the lower edge of said door opening, said table plate having openings therein, a spark arrester forwardly of the table plate and extending across the housing in a substantially horizontal position, means insulating said disc member below said spark arrester, and a header plate arranged forwardly of the boiler tubes, and said header plate having openings therein covered with netting to permit the escape of gases therethrough.

2. A locomotive front end structure comprising, a housing, a smoke stack extending upwardly through said housing, a nozzle exhausting into said smoke stack, a header plate having openings therein, nettings covering said openings, at horizontal table plate within said housing forwardly of said table plate, a horizontal spark arrester forwardly of said table plate, the openings in said nettings and the openings in said table plate and the openings in said spark arrester being so dimensioned and arranged as to provide for the escape of approximately sixty per cent of the exhaust gases through the spark arrester and approximately thirty per cent of the gases through the openings in said table plate and approximately ten per cent of the gases through said header plate nettings and means including a door arranged above said table plate and said spark arrester closing said housing.

3. A locomotive front end structure comprising a housing having an opening in the end thereof, a removable closure for said opening, a plurality of flue tubes, a super-heater unit including heater elements extending into some of said flue tubes, a header plate arranged forwardly of the ends of the flue tubes, said header plate having openings therein substantially aligned with the connections of the heater elements with the superheater and with the associated flue tubes, nettings covering said openings in the header plate, a substantially horizontal apertured table plate extending forwardly from the header plate, and a. substantially horizontally arranged spark arrester whereby the flue tubes and the heater element connections may be observed from the front end of the locomotive through the openings in said header plate,

JOSEPH G. VALLELY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 38,111 Hovey Apr. 7, 1863 271,255 Milholland Jan. 30, 1883 439,892 Pattee Nov. 4, 1890 950,005 Mosley Feb. 22, 1910 1,174,623 Seiders -1 Mar. 7, 1916 1,245,284 Stannard Nov. 6, 1917 1,286,553 Deinert Dec. 3, 1918 1,545,434 Lewis July 7 ,1925

FOREIGN PATENTS Number Country Date 15,085 Great Britain July 24, 1901

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