US1700789A - Draft and exhaust regulating means - Google Patents

Description

DRAFT AND EXHAUST REGULATING MEANS Fi J1me 1924 2 Sheets- Sheet 1 W Y Jam a. 22 mm Feb. 5, 1929. 1,700,789

J. N. EDWARDS DRAFT AND EXHAUST REGULATING MEANS Filed June 12. 1924 2 sheets-sheet 2 A g I 1,700,789

FFWE.

rarest] JOHN N. EDWARDS, OF DECATUR, ILLINOIS.

DRAFT AND EXHAUST REGULATING MEANSI Application filed June 12,

This invention relates to improvements in draft and exhaust regulating means and 1s particularly adapted for application to steam boiler and engine installations.

The object of my invention isto provide means of this character which may be applied to locomotive or other mechanisms, and which will permit either automatic or manual consages.

In the present day locomotive construction the steam exhausting from the cylinder and valve chests passes through an exhaust nozzle located beneath the stack so that the exhaust steam is utilized to increase the draft through the firebox. When the pressure'of the steam in the boiler approximates the permitted maximum above which the safety valve is set to blow off, the use of the locomotive may serve to greatly enhance the draft, although obviously at such a time it would be advantageous to decrease the draft and there by avoid waste of steam through blow off of the safety valve. Then, too, the provision of added exhaust sectional area operable at the option of the engineer will increase the efliciency of operation, especially when climbing grades or starting under heavy load, orin short where the expansive action'of the steam cannot be fully utilized. V c Y The above and other objects will be more fullydescribed and set forth in the following specification and shown in the accompanying drawings, in which- V p f Fig. 1 is a front elevation of a locomotive showing my auxiliary exhaust ducts applied thereto, the View being toward the front of the locomotive. Fig. 2 is a side elevation of apparatus embodying my invention, a portion ofthe locomotive being indicated in outline. I Fig. 3- is a vertical section through .what I term the automatic control valve. Q 4 is a section through one of theexhaust valves. a Fig. 5 is a section through the pop valve. Like numerals refer to like elements throughout the drawings. I

I have indicated'more or less diagrammati cally and in outline in Figs. 1 and '2 a typical locomotive having the cylinders and valve chests 11. Located in the smoke chamber is the nozzle indicated in dotted lines in Fig. 1, to which lead the exhaust ducts '16 from the valve chests 11. Located above the nozzle 15 is the stack 17. Tapped into each 1924. Serial No. 719,650.

exhaust passage is an exhaust valve shown in anenlarged section in Fig. 4. v

These exhaust valves are constructed with a main poppet valve 20 mounted upon. stem 20 which has the boss 20 at the valve back.

The valve 20 normally seats on valve seat 20 to close an auxiliary exhaust duct 21 attached to the elbow portion 20 in suitable manner.

Near the upper portion of the exhaust valve casing 20 is a chamber 20 in which is reciprocably mounted the piston 20 carried on the stemjQO", and smaller in effective area than the poppet valve 20 The coiled spring 25 extends between the upper face of'piston 20 and a centering boss 27 of cap 27, which is threaded upon the casing 20. As will be obvious, the ca'p27may be adjusted-to vary the compression of spring 25, and thereby the resistance to movement ofpiston 20 Similarly vent 27 is p'rovidedin thecapto prevent dash-pot action upon movement of the piston 20?. Communicating with the chamber 20 beneath the lowermost position of piston 20 is the inlet port28, at which'terminates'th'e pipe 30. The partition 27 is apertured to ac-' commodatewthe stem 20 and is recessed pressure obtains in theduct 16, this pressure will act upon the lower face of the poppet valve piston20 but will be over-balanced by the compression in' spring 25 when below a selected point. As will be described below,

fluid under pressure may be applied through port 28 to overcome the pressure of the spring, 25 and move valve 20 to open position to act as an auxiliary exhaust through the duct 21, which terminates exteriorly of the stack 17 I Located inth'e cab, although this location is not necessary, is provided an automatic control valve generally indicated by numeral 35. j This comprises the compound chamber having a relatively large'p'ortion 35 'and'a relatively small portion 35? In the former is reciprocably'mounted the large piston 35, and in the latter a "relatively small piston 35, these pistons being joined by a single rod 35 The cap 35 seals the end of the cham ber 35, while a similar smaller cap 35 seals the opposite end of small chamber 35 From and 35 at the opposite side of piston 35 from port 35 when the piston is inshut-ofi position. The pipe terminates at port and an exhaust pipe 38 depends from -port'35 opening into the atmosphere forexhaust.

v A drain pipe 39 extends from casing 35 to any desired point and transmits the condensed steam from drain vent 35 A pipe or tube 40 extends from poppet valve casing (described below) to port 35 Air or other .fiuid under pressure is transmitted through pipe line-46 to port 35, where it will be delivered between the pistons 35 and 35 Normally the excess of area of the former will result in the coupled piston being retained in left hand position as viewed in Fig. 3. A branch pipe 49 extends from pipe line 46 to pipe 4-0, and is in communication with both, a manually operable valve 50 being provided to openor close the pipe 49.

Located upon the boiler and in connection with the interior thereof is what 1 term the pop valve 45, comprising a casing 45 having the projecting boss 45* onits-top for engagement by a wrench'or the like. This casing is also'provided with a small vent 45. The

casing 45"is threaded at its upper end upon the flange 45 of the body portion. A ring 45 is secured upon the shoulder 45* of the main body portion by thebolts 45, thus providing a small chamber 45 -from which leads the outlet 45 The upper end of the pipe 40 is connected to'this outlet. The main passage 45 -in communication withthe boiler is provided in the body portion of the valve and normally closed by valve 52 normally seated on the valve seat 45 toclose communication between the passage 45 and chamber 4L5. The valve 52 is provided with the reduced shoulder 52, which extends upwardly through suitable closely fitting aperture in the ring45 thelatter being recessed to accommodate the juncture 52* between the shoulder 52 and the main valve 52. Up Wardlyo'f the shoulder52 extends the valve stem 52, around which ismountecl the coiled compression spring 53, held in position at the upper end by. the stud s5 dependingfrom theinside of the casing 45. Thecasing 45* maybe adjusted relative "to the ring 45 -to vary the compression in the spring 53.

The compression-spring 53 maybe adjusted topermit opening of the valve 5.2 at any desired steam pressure in the main boiler, for exampleat three pounds-less than that at which "the safety valve would ordinarily blow off. Assuming this pressure to have reached the ,point of lift of valve 52, steam will flow through passage 45*, pipe 40, port 35 whereupon pressure thereof acting against the outer face of the piston 35 will 'move-the same to the right as viewed in Fig.

3. This will-result in communication being exhaust passages independently of the auto-,

matic control, manual valve 50ma'y be actuated, which will result in air under pressure flowing through pipes 4-9 and 40 into port 35 which will result in the movement of pistons 35 and 35 to the. right, which as described before will permit flowof air under pressure to the exhaust valve 20 to actuate the same. This is desirable as explained in the preliminary outline hereto, as it in effect reduces the back pressure of the exhaust steam and increases the differential between the maximum and minimum steam pressureduring the cycle, thereby increasing the mean effective pressure and the delivery of power during the cycle.

While I have shown a pair of exhaust valves 20 and apipe 21 leading from each to a common exhaust, it will be apparentithata single valve of this character can be utilized to control the auxiliary exhaust from both cylinders without departing from the spirit of my invention. Similarly it will be apparent that my invention is applicable to stationary steam engines.

I do not wishto be restricted to the form shown and described except as defined in the appended claims.

What I claim is:

1. In combination a source of steam,-mecha-nism actuated thereby, a draft nozzle, an air line, a mechanism actuatable by said steam, a main exhaust duct leading therefrom to said nozzle, an auxiliary exhaust ductleading therefrom to the atmosphere, a valve c0-' acting'with said auxiliary exhaust duct, an air duct leading from said air line to said valve, controlling means normally closing said air duct and actuatable'by said steam at selected pressure to open said duct.

2. In combination a source of steam, an air line, a draft nozzle, a mechanism actuatable by said steam,-a main exhaust duct leading therefrom to said nozzle, an auxiliary exhaust duct leading therefrom, a valve coacting with said auxiliary exhaust .duct,

an air duct leading from said air line to said.

at selected pressure to open said duct, and

a valve manually operable to permit flow of air to said control means to actuate the same.

3. In combination with a source of steam, mechanism actuatable thereby, a draft nozzle, an exhaust passage leading from said mechanism to said nozzle, an auxiliary escape duct, a normally closed exhaust valve associated therewith, an actuating fluid supply line, a second duct leading therefrom to said exhaust valve, a normally closed control valve associated with said second duct, a third duct leading from said source of steam to said control valve, a pressure-actuated valve normally closing said third duct and constructed and arranged to open and remain open at or above a selected steam pressure whereby said control valve will be actuated to permit the flow of actuating fluid to said exhaust valve to open the same.

4:. In combination with a source of steam, mechanism actuatable thereby, a draft nozzle, an exhaust passage leading from said mechanism to said nozzle, an auxiliary escape duct, a normally closed exhaust valve associated therewith, an actuating fluid supply line, a second duct leading therefrom to said exhaust valve, a normally closed control valve associated with said second duct,

a third duct leading from said source of steam to said control valve, a pressure-actuated valve-normally closing said third duct and constructed and arranged to open at a selected pressure whereby saidcontrol Valve will be actuated to permit the flow of actuating fluid to said exhaust valve to open the same, and a fourth duct leading from said actuating fluid supply line to said third duct, and a manually operable valve to openv and close said fourth duct whereby actuating fluid from said supply line will be supplied.

to said control valve'to actuate'the same to permit the flow 0f actuating fluid to said exhaust valve.

5. In combination a source of steam, an air line, a mechanism actuatable by said steam, a draft nozzle, a main exhaust. duct leading therefrom to said nozzle, an auxiliary exhaust duct leading therefrom, a valve coacting with said auxiliary exhaust duct, an air duct leading from said'air line to said valve, controlling means normally closing said air duct and actuatable by said steam at selected pressure to open said duct, and a valve manually operable to permit flow of air to said control means'toactuate the same, said controlling means being adjustable for actuation by said steam at different desired pressures.

In witness whereof, I hereunto subscribe my name to this specification.

JOHN N. EDWARDS.

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