US2937845A - Automatic blowdown for steam separator - Google Patents

Description

May 24, 1960 J. E. LA ROCQUE ET AL 2,937,845

AUTOMATIC BLowDowN FOR STEAM sEPARAToR Filed Nov. 22, 1954 s sheets-sheet 1 Si 'lumi 'JOSEPH E. LA 90cm/E FLY/94 CHAQLES E. IMPEY May 24, 1960 J. E. LA RCQUE ET AL AUTOMATIC BLowDowN FOR STEAM sEPARAToR 3 Sheets-Sheet 2 Filed Nov. 22, 1954 ITZEHZDEE dose/DH E. LA Roem/E ,fl z M f im,

.0 9 3 Q M) w @XM o NJN// 7 Vo .M5 4 4 4 E 7 May 24, 1960 J. E. LA ROCQUE ETAL AUTOMATIC BLOWDOWN FOR STEAM SEPARATOR 3 Sheets-Sheet 3 Filed Nov. 22, 1954 JEZEHZDEE I JOSEPH E. LA QocQuE CHARLES E. /NPEY h United States, Patent AUTOMATIC BLOWDOWN FOR STEAM SEPARATOR `loseph E. La Rocque, Chicago, and Charles E. Impey, Lombard, Ill., assignors to Vapor Heating Corporation, Chicago, Ill., a corporation of Delaware Filed Nov. 22, 1954, Ser. No. 470,182

1 Claim. (Cl. 251-14) The present invention relates to automaticY blowdown control mechanism for steam separators associated with steam generators of the water-tube coil type such as are usually employed to supply steam to the heating lsystems of diesel powered passenger trains. The invention 'is however capable of a wide variety of other uses and the same may readily be employed, with or without modication, for stationary installations wherein a plurality of steam generators are used for supplying steam and it is desirable to blow down their steam separators from a remote location at predetermined intervals. The invention, for illustrative purposes, is herein shown and described in connection with diesel powered passenger trains wherein it has particular advantages that will appear presently.

Diesel locomotive installations usually employ one or more steam generators to supply steam to the heating equipment of the locomotive and the trainof passenger cars connected thereto. Steam separator units associated with such generators receive a mixture of steam and hot water from the generator coils near the top of the unit and yoperate upon the gravity principle to separate the steam from the water. The mineral constituents in the water are coagulated by the reaction of heat and water treatment chemical introduced therein and these minerals, in the form of sludge, are carried by the water into the separator. The water and mineral sludge drop to the bottom of the separator while the steam is conducted 'from the top of the separator unit to the various heat exchange devices vwhich may be employed in the heating system. To prevent undue accumulation of such sludge in the separator unit a blowdown vvalve is provided at the bottom of the unit whereby the sludge accumulation may periodically be ejected from the separator to the atmosphere.

Heretofore, Where manual blowdown operations were resorted to, infrequent and irregular blowdowns resulted in undue waste of water as well as frequent clogging of the separators. In passenger train installations involving two or more locomotives, or dual locomotive units, eiective blowdown operations necessitated the services of a trainman, usually a reman, and required himito leave his station in the locomotive cab and walk through the various articulated units of the locomotive to effect the necessary blowdown operations of the-steam separator associated with the steam generator in such units. In railroads encountering bad water conditions, high water consumption and frequent clogging of the steam separators have become factors that materially add to the cost of maintenance.

The present invention is designed to overcome the above noted limitations that are attendant upon manual blowdown operations in vpassenger train operation and, toward this end, it contemplates the provision of a separator blowdown control mechanism which will operate automatically to blow down the steam separator of a steam generator, or to simultaneously blow down the separator unitsof all steam generators employed in any particular train installation, at frequent predetermined intervals with each blowdown operation lasting a predeterf mined period of time.

In carrying out these aims, brieliy, the invention contemplates the-provision of an electrically operated control valve, one of which may be employed for operating an air cylinder associated with each blowdown valve'of a steam separator, together with a compact unitary assemblage of electrical control mechanism, kcapable of 'being installed within a control boit or on a control panel ata location remote from` the steam generating plant, which mechanism is timer controlled so that automatic blowdown operations will take place according to a predetermined time schedule. The control mechanism further .includes a main switch by means of which the apparatus may be set for automatic operation or disabled at will and also includes push button means whereby, if desired, manual control of blowdown operations may be effected so as to completely purge all separators of collected sludge before the train enters a station and immediately after the train leaves the station.

The provision of a blowdown control apparatus of the character briefly outlined above being among the Yprin- .cipal objects of the invention, other objects and advantages will appear as the following description ensues.

control mechanism showingthe same partly in perspec.-

tive` and partly in section as being applied to a blowdown valve associated with a steam separator. v Fig. 3 is' an elevational viewV of a steam generator having a steam separator associated therewith and showing the control mechanism of the presentrinvention applied thereto. v Fig. 4 is a plan view of a control panel on which certain of the present control equipment is mounted.,`

Fig. 5 is an enlarged sectional view taken substantially along the line 5-5 ofrFig. 2; and l Fig. 6 is a sectional view taken substantially along the lined-6 of Fig. 5. l f i Referring now to the drawings in detail, in Fig. l there is illustrated a pair of diesel locomotive units operatively connected to a train of passenger cars.Y The leading and trailing diesel units 10Vand 11 respectively each include in addition to itsdiesel power plant, a steam generator 12 of the coiled water `tube type such as has been illustrated in moredetail'in Fig. 3, and each Agenerator 12 is operatively Vconnected-to a steam separator 13 hav,- ing a blowdown valve 14 and with which valves thecontrol mechanism of the present invention is operatively associated. As shown in Figs. 1 and 4, certain portions of 4this control mechanism are operatively mounted on a control panel 15 suitably located in the cab ofthe diesel'.

ploye'd for tiring the generator. The ignition and burner structure is designated collectively at Z5 andthe 4outlet delivery valvesY 26 from the generator are shown as being connected by means of a conduit 27 to a region near the upper end of the steam separator 13. The steam separator is also of conventional design and is in the form of an elongated closed cylinder or tank 28 at the top of which there is mounted the usual lead-off valve 30 by means of which steam that has been separated from its mineral constituents is sentthrough a pipe line to the heat exchangers or other devices (not shown) associated with the passenger car heating system. The lower end of the steam separator cylinder 28 is provided with a central threaded opening 31 (Fig. 2) in which there is threadedly received the tail piece 32 of the blowdown valve assembly 14.

The valve assembly 14 further includes a valve body 33 having an inlet passage34 in communication with a passage 35 in the tail piece 32 and connected to the latter by a union ring 36. The valve body also has an outlet passage 37 for sludge in communication with a nipple 38 which .is held in position by a union ring 39. The tail piece 31 is provided with a valve seat 40 which cooperates with a valve element 41 carried at the upper end of a valve stem 42 which passes through a gland 43 and the stem 42 is spring pressed as at 44 to normally maintain the valve element 41 seated on the tail piece seat 40.

As shown best in Figs. and 6, the valve element 41 is adapted to be lifted from its seat 40 by depression of a foot pedal 45 pivoted as at 46 on a rocker arm o1' lever 47 which in turn is pivoted as at 48 to an angular bracket 49 (Fig. 5) secured by studs 50 to the valve body 33. A pair of springs 51' serve to maintain the pedal 45 in its elevated position. The lever 47 has one end thereof disposed below and in engagement with the lower projecting end of the valve stem 42 and thus it will be seen that upon depression of the foot pedal 45 and consequent clockwise movement of the lever 47 as viewed in Fig. 6, the valve stem 42 will be moved upwardly to lift the valve element 41 from its seat to e'ect the blowdown operation. 4In order that the operator may effect a prolonged blowdown operation without having to maintain foot pressure on the pedal 45, a locking pin 52 extends upwardly from the body of the pedal and is designed for locking engagement with an abutment 53 formed on the bracket 49. By forward tilting of the pedal 45 after depression thereof, the operator may align the end of the locking pin 52 with the abutment 53 (Fig. 5) to hold the valve 41 open. Release of the locking pin may be effected by a reverse operation of the pedal 45.

The blowdown valve 14 per se when operated by a foot pedal 45 is conventional structure. The novelty of the present invention resides rather in the novel construction, combination and arrangement of parts about to be described in detail whereby the blowdown operations may be automatically performed at spaced intervals. Referring now to Fig. 2, an air cylinder assembly 60 is provided for each of the blowdown valves 14 and is adapted to be secured to one flange of the angular bracket 49 by mounting screws 51. Each air cylinder includes a caslng 62 providing a cylinder 63 therein in which there is slidable a piston 64 carried on a plunger 65 which projects downwardly from the casing and carries at its lower exposed end an adjusting stud 66 by means of which the elective stroke of the plunger may be varied within small limits. The stud 66 is designed for engagement with one end of a rocker arm 67 which is pivoted as at 68 to one arm 69 of the angle bracket 49 secured to valve 14. The other end of the rocker arm 67 'carries an adjusting stud and lock nut assembly 70 which underlies the operative end of the lever 47 associated with the foot pedal 45 and which is designed for engagement therewith.

The cylinder 63 is bled to atmosphere as at 71 below the piston 64 and above the-piston it is connected through :a conduit 7219 ,the Outlet port I3 of a solenoid actuated valve assembly 74 operable upon energization thereof to admit air under pressure to the cylinder 63 through the conduit 72 to drive the piston 64 downwardly in the cylinder 63 and thus cause counter-clockwise movement of the rocker arm 67 to elevate the valve stem 42 and lift the valve element 41 from its seat to effect a blowdown operation.

The valve assembly 74 includes a casing 75 provided with an air inlet port 76 and a bleeder port 77, the port 76 being connected through a conduit 78 to a suitable source of air under pressure (not shown). The ports 76 and 77 communicate through a common passage 80 with the outlet port 73 and a pair of internal valve seats 81 and 82 at the ends of the passage 80 cooperate with a dual valve and stem element 83 to selectively maintain the valve seats 81 and 82 open or closed in a manner that will be described presently. The valve element 83 is operatively connected to the movable core S4 of a solenoid assembly having a winding 85 operable upon energization thereof to move the valve element 83 downwardly within the casing 75 to establish communication between the air conduit 78 and conduit 72 through the ports 76 and 73 to effect the blowdown operation as previously described. Upon deenergization of the winding 85 the valve element 83 is restored to its normal position under the influence of a spring 86 to establish communication between the ports 73 and 77 and bleed the cylinder 63 to atmosphere above the piston 64 and thus terminate the blowdown operation.

The electrical control instrumentalities whereby the magnet winding 85 of each solenoid valve 74 employed in any particular installation may be periodically energized include a timer mechanism 90, schematically shown in Fig. 2 and which is conveniently mounted on the control panel 15 (Figs. 1 and 4). This timer mechanism 90 operates to control the opening and closing movements of two cam operated switches 91 and 92 and is arranged in series in the electrical circuit for the solenoid valve winding 85. A push button 93 permits manual blowdown operations at any desired time irrespective to the positions of the cam operated switches 91 and 92.

It has been found that in normal train operation it is desirable to effect blowdown operations for a fixed time period at predetermined intervals of time. The particular time period of the blowdown or the intervals bc tween such operations may vary, depending upon the quantity of sludge forming minerals contained in the Water in the region through which the train is operated. Where pedal operated separator blowdowns are concerned it has been the practice of the trainman to appear at each blowdown station periodically and depress the foot pedal 45, so as to open the blowdown valve 41 for such period as the trainman deemed proper to clear the sludge from the separator. Before entering a station and immediately after leaving the same, it has been the custom to eect a longer blowdown impulse, utilizing the lock pin 52 and abutment 53 as previously described. The timer mechanism 90 of the present invention is designed to simulate these desired blowdown impulses with rhythmic accuracy and in an unfailing manner but with an accelerated frequency which is impractical where manual operations are concerned.

Accordingly, as shown in Fig. 2, the cam switch 92 is adapted to be closed by the timer mechanism at predetermined intervals, for example ve minutes, and to remain closed for a shorter period, for example seconds during each ve minute interval. During said tive minute period the cam switch 91 is closed a number of times, for example once each twenty seconds, and remains closed for at least one second. Consequently an energizing circuit to the solenoid 85 of the air valve structure 74 is completed once during the time that the cam switch 92 is closed.

To effect the above described blowdown operations, closure @fthe master switch S will establish a circuit through the timer motor M, the circuit extending from a suitable source of current B, which may be a battery, through lead 94, switch S, leads 95, 96, motor M, and leads 97, 98, back to the source. Energization of the motor M serves to drive a timer cam 99 through a iirst gear reduction train 100 and the cam 99 is formed with a peripheral notch 101 which cooperates with a cam follower 102 to permit periodic closing movements of the cam switch 91 for the duration of one second duringv each twenty second interval of time. The timer cam 99 is connected to a second timer cam 103 through a second gear reduction train 104.A The cam 103 is formedV with a peripheral notch 105 which cooperates with a cam follower 106 to permit periodic closing of the cam switch 92 for the duration of twenty seconds during each iive minute interval.

After initial closure of the switch S the system will continue to operate indefinitely and the cam switch 91 will become closed for the brief interval of one second at the end of each twenty second interval. Such closure of the cam switch 91 will be ineffective to energize the magnet winding 85 until such time as the cam switch 92 becomes closed at the end of each five minute interval. At such times as both switches 91 and 92 are closed a circuit will exist extending from the source B through lead 94, switch S, leads 95, switch 91, lead 107, switch 92 and leads 108, 109, magnet Winding 85, and leads 110 and 98 to the source. Energization of the winding 85 will, of course, etect the blowdown operation for the duration of such energization, as previously described.

From the above description it will be seen that the timer cam 103 serves to establish a twenty second period of time at the end of each tive minute interval during which the switch 92 becomes and remains closed so that during this period the separator 28 is potentially capable of blowdown operation subject to the intermittent opening and closing of the switch 91 under the control of the timer cam 99. During the remainder of the iive minute interval, the switch 92 is open, and the periodic intermittent closure of the switch 91 is without elect.

If kat any time it isdesired to effect manual blowdown of the separator 13, the push button contacts 111 may be manually closed and such closure thereof will establish a circuit through the solenoid valve winding 85 extending from the source through the contacts 111, leads 112, 109, winding 85 and leads 110 and 98 to the source. It is to be noted that this circuit is capable of being established at any time whether the switch S is open or closed. The push button contacts 111 are designed to permit manual blowdown of the separator immediately prior to entry of the locomotive into a station. After such blowdown operation, the operator should open the master switch S and leave the same open until after the locomotive has left the yard or station to disable the auto- A terminal block 113 is mounted on the panel 15y and makes provision whereby the solenoid valves 74 of the variousseparators of the train assembly may be connected in electrical parallel for simultaneous operation by the timer control mechanism 90.

We claim:

A blowdown assembly for a steam separator having a normally closed blowdown valve including a casing and a stem projecting from said casing, means selectively operable for opening said valve includinga manually operable lever having an end portion engaging said projecting end of the valve stem which lever is movable individually in a direction to open said valve, a bracket secured to the casing for supporting said manually operable lever and provided with a stop surface thereon, a

second lever intermediately pivoted on said bracket and.

positioned to effectively bear at'one end against the valve stem engaging end of said manually operable'lever, a pressure fluid motor mounted on said bracket for operatively engaging the other end of said second lever to rock it and the said manually operable lever in a direction to open said valve, and means carried by said manually operable lever for releasably engaging said stop surface on the bracket to lock the said manually operable lever in its valve operating position.

References Cited in the le of this patent UNITED STATES PATENTS 388,860 Greenwood Sept. 4, 1888 633,415 Batchelor Sept. 19, 1899 1,078,986 Becker Nov. 18, 1913 1,082,821 Richards Dec. 30, 1913 1,189,078 Evans June 27, 1916 1,318,120 Wheaton Oct. 7, 1919 1,561,412 Davis Nov. 10, 1925 1,689,509 Vissering Oct. 30, 1928 1,961,157 McCoy June 5, 1934 2,019,766 Peterson Nov. 5, 1935 2,167,266 Kimball July 25, 1939 2,204,532 Erbguth et al. June 11, 1940 f 2,408,883 Rode Oct.8, 1946 2,531,257 Cowherd Nov. 21, 1950 2,577,155 Rex Dec. 4, 1951 2,582,285 Schellens Ian.v 15, 1952 f 2,598,535 Green May 27, 1952 2,601,264 Daugherty June 24, 1952 2,639,729 Tulumello May 26, 1953 2,668,589 Illian Feb. 9, 1954 2,738,807 lAddison Mar. 20.

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