US2082953A - Blow-off apparatus for locomotive boilers - Google Patents

Description

June 8, 1937. L.. o. GUNDERsoN BLOW-OFF APPARATUS FVOR LOCOMOTIVE BOILERS 2 Sheets-Sheet l Filed Dec. 30, 1935v June 8, 1937.

L o, GuNDERsoN LOW-OFF APPARATUS FOR LOCOMOTIVE BOILERS Filed Deo. 30, 1935 2 Sheets-Sheet 2 ...llllllllllllllll llilllll.

YE F 'l' @Caza/Ls- 0. @JM

Patented June 8, 1937 UNITED STATES BLOW-oFF APPARATUS Foa LoooMoTlvE ABoILERs.

Lewis 0.`Gunderson,` ChicagoQIllQa-ssgnor to Dearborn Chemical Company,

corporation of Illinois Chicago,` Ill., a

Application December so, 1935...se`r'ia1N0. 56,835

2 claims. (o1. 122-3821 This invention relates to blow-off apparatus for locomotive boilers and? to a method of blowing olf suchl boilers. f

Automatic blow-off apparatus for locomotive boilers has heretofore been proposed to effect a simultaneous blowing off of the boiler whenever steam is being delivered from the boiler `to the locomotive cylinders. Such an 'arrangement, however, is wasteful because it causes the boiler to be blown off at the same rate whenever steam is being delivered `to the cylinders regardless of the amount of steambeingrsov delivered. n

It is therefore an important object of this l5 invention to provide blow-olf apparatus-for' locomotive boilers that will' effect' a constantn blowoff of the boiler whenever but only when Vsteam is being delivered into the cylinders in excess" of a predeterminedy rate, whereby itis possible to open the throttlevalve toa drifting position without opening the blow-olif` valve. This is desirable because arelatively small' Vamountl of steam is used Iduring such periods as theV throttle is: infa drifting position and for that reason it' would' not bexecient to' continue to blow down the boiler at thezsame rate aszwhen steam is used forfull' operation of the locomotive.

It is afurther important object of thisinvention to provide blow-olf apparatusA for locomotive boilers wherein the blow-off valve isf controlled `through the operation' of a trip valve, which in turn is actuated by the throttle lever whenever and only when' the throttle lever'is openedv a predetermined distance. 'I

It is a further important'iobject of this' invention'to provide in a blow-olf apparatus fon'locomotiveV boilers a` specially designed trip-valve., operated mechanically by the'operation of the throttle lever and in accordance with the position of the throttle lever, whereby delayed action in opening the valve is provided so that the valve will be openedonly at a predetermined opening of thethrottleY lever.

Other and" further important objects 4of this invention will be apparentfrom the disclosures in the specification and the accompanying drawings. 4 I

This invention (in a preferred form) is illustrated in `the drawings and hereinafter more fu-lly described.

On the drawings?` f i Figure l is abroken side elevationalview of `an installation ofmy blow-offapparatus on a .locomotive,.the latter being shown in dotted outline. Figure 2 is a fragmentary rear elevational view showing the trip'valve and mechanism connecting the same to the throttle lever.

Y Figure 3 is an enlarged longitudinal sectional view of the trip valve.

viewof the blow-olf cock and connection.

lFigure 5 isla fragmentary sectional View taken substantially on the line V-Vof Fig. 4.

As shown on the drawings: i

The reference numeral Illindicates generally a locomotive and the reference numeral II a tender drawn thereby. The locomotive I0 comprises the usual cab I2, cab turret I3, and steam dome. I4housing a throttle valve I5 mounted in the steam line I6 leading from the boiler I'I to the cylinders (not shown). Y

As is customary, the throttlevalve I5 is controlled through a bell crank `lever I8 and connecting rod I9 by a throttle lever 20. Said throttle lever 201 is pivoted at one end thereof as at 2I. (Fig. 2) in a support secured to the rear wall. of the boiler and is connected intermediate itsends through a clevis 22 formed on the end of the rod I9 that protrudes into the cab I2. The other end `of lthe throttle lever 20 is provided with a handle 23 that may be moved in and out by the engineer in charge of the locomotive. While the clevis connection4 22 has been shown as being spaced considerably from the pivot 2Ifor purposes of convenience it Ashould be understood that `actually these points will be closer together thereby providing a longer lever arm for the lever 20 to permitan easier manual operation of the throttle valve.

A trip valve 24 is mounted upon a bracket 25 secured to the rear face of the boiler. Said trip valve 24 is provided with a handle 26, which is pivoted `as at 21 and provided with an aperture 28` (Fig. I3)v `to receive the` stem 29 of the valve proper 30. -Saidhandle 26 is provided with an offset end 3I `(Fig. 1) `against the lower face of which `the throttle lever 20 presses as the throttle lever is pulled outinto opened position. As will be .readilyapparent since the throttlezlever 20 movesA in a horizontal plane, the handle 26 will be raised as the offset end 3I rides on the throttle lever 20, thereby lifting the valve stem 29 and opening the valve 30.

Said trip valve 24 comprises a passage body portion 32 having a steam inlet connection 33 and a steam outlet connection 34 for connecting the valve into a steam line 35 leading from the vcab turret I3 to a blow-oil cock 36. An apertured partition 31 extends between the inlet 33 and outlet 34 and is` fitted with a valve seat 38 for receiving the end of the valve 30. Said valve stem 29 extends through a bonnet 39 which is secured to the body portion 32 by means of a flanged nut 48. A spring 4| surrounds the lower 5 end of the stern 29 and is mounted under compression between a washer 42 received within a recess 43 in the bonnet 3 9 and the valve end 3U. Said spring 4| thus normally holds the valve in closed position. f l0 The blow-ofi cock 36 comprises a passaged body portion 44 having aV steam inlet 45 for connection to the pipe 35, a boiler water and sludge inlet 46 for connection with a line 41 leading from the bottom portion of the boiler, and an intermediate boiler water and sludge discharge opening 48 for receiving a discharge connection 49. Said body portion 44 is provided withan internal seat 50 about a port 5| that provides communication between the steam inlet 45 and the discharge 48. A piston 52 is slidably mounted in the cylindrical portion 53 above said port 5| and is adapted to seat against the seat 50 by virtue of the steam pressure-on theV relatively large area of the top 52a of the piston. Said piston 52 is provided with an upper cylindrical portion 54 that extends into a recessedplug 55 and which is provided with a condensate duct 56 to yprevent the condensate from being trapped above the end 54. The body of the piston 52 is also provided with a condensate duct 5'! to permit drainage into'the discharge side of the cock. M

VThepiston 52 is'also provided with anelongated reduced lower end 58'for'a purpose that will presentlyY appear. E'Theb'ody portion 44 is provided with a threa'dedopening 59 between'V the Aboiler water inlet and discharge connections Vfor f receiving an apertured seat insert. A ball 6|, preferably of stainless Steel, is adapted to be held in seating engagement with said insert 60 by means of a coiled spring 62'mountedin a recessed bossV or plug'63. Said plug 63 is threadedinto the apertured lower kend 64 rof the bodyportion 44 and is provided with a centering boss'65 and upstanding segmental Vcylindrical lugs 66 that cooperate to center and'position the coiled spring 62. Y

When Ysteam under' pressure is admitted to the inlet'45 to the space above the piston 52, the steam pressure thereby exerted against the upper face 52a ofV the piston causes the piston to be depressed until it seats itself inV the'seat 5 0, the elongated end 58 of the piston .at the same time pressing against the ball 6| to unseat it and provide a continuous passageway between the boiler water inlet and outlet passages '46 and 48, respectively. VWith the valve thus opened to blow off boiler water and sludge from the boiler, both the under and upper sides of the piston 52 will be subjected to boiler pressure due to a restricted 60 orifice Vcommunicating with the discharge opening 48 as will be hereinafter described.- However, owing to the reduced area of theundersideof the piston, the total pressure against the'upper side 5211.` of the piston `will be greater'and'thus hold 65 the piston in its lowered, seated position'without chattering so long as vsteam is admitted through 'Y the pipe 35 into the'chamber above the piston.

When the steam pressure above the piston is released, the excessiveforce of thecoil 62 serves 70 to seat the ball 6| and raise the piston from its seat, into the position shown in Fig. 4. The condensate grooves 56 and 51,v prevent condensate from being trapped above'the body of the piston. The discharge connection 4,9 comprises a nipple 75 threaded at both ends and provided withk a lower .Y ciple involved is that the pin protruding through the oriiice 12 will prevent flat particles of scale `from` stopping -up the orifice completely, inasmuch as any scale entering the orice nipple will lodgeat an angle against the pin and prevent the possibility of complete stoppage of the orifice. Furthermore, by unscrewing the plug 10, the pin will serve as a cleaning instrument for the orice 12.

Theft-shaped member 6B is connected through its lower threaded opening 14 with a boiler water and sludgedischarge line 15 of substantially greater diameter than the diameter of the orifice 12. Said line 15 leads to a steam separator 16 of any conventional or commo-n construction such as a centrifugal separator, wherein the steam blown from the boiler with theboiler water and sludge is separated from the boiler water and sludge. The separator 16 may be conveniently mounted on the cab, as from the underside of the floor of the cab, so that the sludge and water draining therefrom through a discharge pipe 11 will flow onto the road bed, indicated generally by the reference numeral 18. The steam is discharged through a pipe 19 leading from the top of the separator 16 into the ashpit 8U and serves to promote combustion in the firebox of the locomotive.

The operation of the blow-off apparatus just described is substantially as follows:

When the steam throttle valve I5 is closed or substantially so, as shown in Fig. 1, the trip valve 24 is also closed, since the horizontal portion of the handle 26 is resting on the throttle lever 20. When, however, the throttle valve l5 is opened up'further and the throttle lever 20 has moved along until it strikes the offset end 3| of the handle 26, said handlestarts to ride upwardly and lift the trip valve 30 from its seat. The point at which the trip valve124 is'operative will obviously depend upon the relative distance between the offset in the handle 26 and the lever 20'when the latter is in closed position. This distance can be varied as `desired by ksliding the valve 24 on its support v25 toward and away from the back face of the boiler.

When the movement of vthe throttle lever 20 has operated to open the trip valve 24, steam .is admitted from the cab turret I3, which is in direct communication with the steam space of the boiler, through the line 35 and through the port of the seat insert 38 into the continuation of said steam line 35 leading to the blow-off cock 36. As already explained, the steampressure thereby created on the top 52a of the piston 52 causes a downward displacement of the piston and an unseating ofthe ball 6| to open the communication from the lower portion of the boiler |1 through the boiler water discharge line 41, the port provided by the seat insert and the discharge opening 48, through the connection 49 to the discharge orifice 12. The boiler water and sludge then continues through said orifice 12 into the discharge line 15 and then to the separator 16, where `steam vis separated and discharged into the ashpit 80. The boiler water and sludge is allowedto drain by gravity through the vertical discharge pipe 11 onto the road bed.

It will thus be apparent that my blow-01T apparatus provides for a constant and automatic blowing off of the boiler through a restricted discharge during such periods as the throttle valve is opened beyond a predetermined amount. Ihe operation of the trip valve is preferably delayed to such a point that so long as the steam throttle is in a drifting position, the trip valve will not be operated and consequently the blowoil cock will be closed. When, however, the throttle valve is opened to such an extent that steam is being delivered from the boilerto the cylinders of the engine in excess of a predetermined rate, the trip valve will be opened to permit a withdrawal of steam from the steam space of the boiler with consequent building of pressure against the upper surface 52a of the sliding piston 52 to an amount suicient to open the blow-off valve.

Thus, with this arrangement, the blowing off I of the boiler is automatic whenever and only when the steam throttle is opened beyond a predetermined position. Consequently, there is no undesirable blowing off of the boiler when only a relatively small amount of steam is being used, as when the throttle is ina drifting position. The amount of the delay in the opening of the trip valve may, as is obvious, be adjusted'either by moving the valve itself closer or farther away from the throttle lever inits closed position, or by changing the position of the offset in the trip valve handle or lever.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. In a locomotive having a steam boiler, a throttle for controlling the flow of steam from the boiler and a lever for operating the throttle, a blow-off device communicating with the boiler, pressure operating means for opening the blowoff device, a pipe communicating with the boiler and said pressure operating means, a valve in said pipe, and means so associated with the valve as to be operated by the throttle lever when the latter is beyond a drift speed position for opening the valve to admit boiler pressure through said pipe to the pressure operated means and thereby open the blow-oil device.

2. Apparatus for blowing off sludge from a locomotive boiler comprising a steam throttle lever, a blow-off valve communicating with the boiler, pressure operated means in said blow-off valve for opening said valve, a trip valve, a steam line communicating with the steam space of the boiler and connected through said trip valve to said pressure operated means in said blow-off valve, and mechanism so associated with said trip valve and throttle valve as to operate the trip valve to admit to the pressure operated means in the blow-off valve for opening said blow-off valve only when said lever is moved beyond a drift speed position.

LEWIS O. GUNDERSON.

Images