US1167508A - Damper for locomotive-superheaters. - Google Patents

Description

i N. T. McKEE. DAMPER FOR LOCOMOTIVE SUPERHEATEN.

APPLICATION FILED SEPT. 14, 1915. v v 1,167,5Q8. r Patented Jan.11, 1916.

2 SHEETSSHEET 2.

ATTORNEYS rinrrnn snares Parana canton.

NEAL TRIMBLE McKEE, OF YONKERS, NEW YORK, ASSIGNOR T0 LOCOMOTIVE SUPER- HEATER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

Specification of Letters Patent.

Patented Jan. 11, 1916.

Application filed September 14, 1915. Serial No. 50,570.

To all whom it may concern:

Be it known that I, NEAL TRIMBLE Mo- KEE, a citizen of the United States, and resident-of Yonkers, county of Westchester, and State of New York, have invented a new and useful Improvement in Dampers for LocomotiveSuperheaters, of which the following is a specification.

My invention relates to dampers and means for operating the same in connection with locomotives having superheaters of the fire tube type; more particularly my invention relates to dampers for locomotives of the character specified which are to be used for switching or other intermittent service where the steam is frequently cut OE and on, and where the demands of the service require that power be furnished for periods which are, relatively short and frequent' Among the objects of my invention are the following: To automatically protect the superheater pipes or elements from being overheated and thereby damaged or burned out; to provide a damper which will automatically perform the just indicated function and at the same time permit the hot gases to pass through the fire tubes which contain the superheater elements at all times except when steam is cut off from the main engine cylinders and the blower is on; and to provide a means for automatically shutting off the supply of steam to the blower during such periods as the main engine cylinders are being supplied with steam.

In carrying out my invention I employ, in connection with a casing surrounding the ends of the superheater pipes where they emerge from the fire or smoke tubes at the froii't tube'sheet, a damper in said casing which" is connected with a steam piston in a suitable cylihd'er or an equiyalent, said piston or its equivalent'being controlled by the joint action of steam leading from the blower connection and steam leading from the steam chest or main steam pipe, so that when the engine is running under steam, the damper will be opened whether the blower be on or not, while, when steam is cut off and the blower is on, the damper will be closed; when steam is cut off from the steam chest and the blower is also cut oil, the

damper is preferably arranged to be open.'

In the prior art are to be found automatic devices comprising a damper arranged to control the flow of furnace gases through the fire tubes, said damper being actuated by a piston in a steam cylinder connected with the steam supply to the engine cylinders and controlled by the engine throttle. In such arrangements, however, the damper is closed whenever the steam supply is cut off so that when the engine is standing idle or drifting wlthout steam the superheater pipes are not receiving any increase of heat units.

In a patent to Hoilmann dated December 12, 1912, and No. 1,011,197 there is disclosed an improved type of the damper regulating device just mentioned in which the superheater pipes have hot gases flowing over thenr at all times except when the bloweris on, whether or not steam is being supplied to the engine cylinders, thereby maintaining a higher average of superheat and securing a resultant greater fuel etliciency. Other advantages are also secured by the Hoffmann invention. Adisadvantage, however, of the Hoffmann arrangement is that, while the blower is turned on and steam is being supplied to the engine cylinders, no fire gases will pass through the fire tubes containing the superheater pipes and consequently the steam will not be superheated.

My invention will be better understood by referring to the accompanying drawings in which Figure 1 represents a central vertical longitudinal section, part elevation, through a locomotive boiler with superheater and a damper (in closed position) with preferred form of regulating device according to my invention; Fig. 2 represents an elevation,-

part section, of the damper (in open position) and regulating device of Fig. 1; Fig. 3 represents, diagrammatically, a modified form of my improved damper and regulating device; Fig. 4c is a representation, similar to Fig. 3, of another modification of my invention; and Fig. 5 represents, similarly to Fig. 3, still another modification of my invention.

In the drawings a certain number of fire tubes, 1, contain superheater pipes, 2, the ends of which terminate'i'n a steam collector casing 3. As shown, th e fire tubes which contain the superheater pipes are considerably larger in diameter than the ordinary locomotive fire tube, but I-rhay, if I choose,

use superheaterfire tubes of usual diameter,

run-ll either making the superheater 'pipes themselves smaller or using a smaller number of such pipes to each fire tube.

Surrounding the entire group of superheated pipe ends, as they emerge from the fire tubes, is a sheet iron casing, 4:, in the lower part of which is arranged a damper, 5, extending substantially across the boiler. Fig. 1 shows the damper in closed position and Fi 2 in open position. When the dam.- per is closed, the casing acts as a battle means which completely cuts oil the flow of furnace gases through the fire tubes, 1, containing the superheater pipes, and when the damper is opened these gases have their maximum freedom of flow. The damper, 5,

is pivoted upon a longitudinal axis 6 and has rigidly attached to it, by a short arm, 7, a counterweight, S, the position of arm and counterweight being so related to the clan per that the counterweight tends to hold the v damper normally open. The blower pipe, 9, is joined by a T connection, 10, to a pipe, 11, leading to the main steam supply and has, somewhere in its length, a control cock (not shown) by which the steam flowing to the blower pipe may be turned on or off. Running forward from the 'l', 10, is a steam pipe, 12, leading to a cylinder,'13, in which is a piston, 1%, having a piston rod, 15. This piston rod is pivoted at, 16, to one end of alink, 17, the outer end of which is pivoted at, 18, to a crank arm, 19, fixed upon the damper axis, 6; The cylinder, 13, may be conveniently aiiixed to the outside 01 the boiler. The other end of the cylinder, 13, is connected by pipe, 20, to the live steam supply outside of the main throttle. As shown, the connection is made to the main steam pipe, but this connection might equally well go to the steam chest or to some other point capable of affording a supply of live steam.

The operation oi my invention isas fol lows: When the locomotive is stationary, with main throttle closed, but with blower on, the blower steam pressure will move the piston toward the damper axis, raising the counterweight and closing the damper, so as to shut off the flow of fire gases over the superheater elements. It, now, the throttle be opened, the steam pressures on the two sides of the piston will be equal to one another and the counterweight will become effective to open the damper; it is not necessary to shut off the steam from the blower. It throttle be closed and blower oli the counterweight will keep the damper open.

In the forms shown in Figs. 3, 4 and 5 the counterweight is omitted. In Fig. 3 there are two alined steam cylinders having their pistons, 14L, 142, connected. by a rod 21. The damper crank arm, 19, is pivoted in an open slot formed in this piston rod between the cylinders. One cylinder, 13, is larger than.

the other, 13 the outer end of the larger cylinder being connected to the main steam pipe and the outer end of the smaller cylinder being connected to the blower. -With the engine standing idle and main throttle closed, but with blower on, the pistons will be moved to the left under the pressure of the blower steam and the damper closed. It, now, the throttle be opened the pistons will be moved to the right and the damper opened owing to the larger area ofthe piston which is acted upon by the main steam supply.

The modification shown in Fig. 4 is identical' with that of Fig. 3, except that the blower nozzle, 9, opens from the smaller cylinder near the innerend thereof. The counterweight 8 (shown dotted) may or may not be used, as desired. With the engine standing still, main throttle closed, and cab blower valve opened the pistons will be moved to the left, the damper closed, and the blower steam supplied to the smaller cylinder will pass out'ot the connecting pipe to theblower nozzle. When the main throttie is opened, with blower on, the pistons will be moved to the right, owing to the larger area of the piston acted upon by the main steam supply, the damper will be opened, and the supply of steam to the blower nozzle cut off automatically. Vith main steam supply and blower supply both cut oil, the damper will be closed by the counterweight, 8, if the same be used.

In the form shown in Fig. 5 there are two cylinders of equal diameter mounted one above the other. The respective piston rods project from the right of the cylinders and are connected by links, 17, to opposite ends of the lever crank arm, 19, fixed to the axis, 6, of the damper. The damper axis is so determined that the part of the lever crank arm joining it to the upper piston is longer than the lever arm joining it to the lower piston. The left hand end of the lower cylinder is connected to the blower and the left hand end of the upper piston to the main steam pipe. Whenthe engine is standing still, with blower on, the lower piston is moved to the right and the damper closed. lVith the main throttle open and steam supplied to both upper and lower cylinders from the main steam sup ply'and from the blower respectively, the same steam pressure will be active on the two pistons but,owing to the longer lever arm acted upon by the piston of the upper cylinder, the pressure tending to move the upper piston to the right will overcome the pressure opposed to .it and the damper will be opened.

Instead of having the cylinders in Figs 3 and 4t alined I may, it I prefer, have them set at an angle with independent piston rods acting on the same crank arm.

Referring to the construction shown in Fig. 4, it is clear that, if the counterweight be used, the arrangement will operate equally well whether the two cylinders be of the same diameter or have unequal diameter as shown.

Various other changes of arrangement and in detail may be made within the spirit of my invention and the scope of the following claims:

1. In a locomotive provided with a blower and a superheater of the class described, the combination with the superheatertubes, of battle means including a damper in the path of the furnace gases, steam actuated means operatively attached to the damper, a steam connection between the main steam pipe and the steam actuated means tending to open the damper and a steam connection between the blower and the steam actuated means tending to close the damper.

2 In a locomotive provided with a blower and a superheater of the class described, the combination with the superh'eater tubes, of battle means including a damper in the path of the furnace gases, steam actuated means operatively attached to the damper, a steam connection between the main steam pipe and the steam actuated means tending to open the damper, a steam connection between the blower .and the steam actuated means tending to close the damper, and a counterweight fixed to the damper and tending to open the damper.

3. In a locomotive provided with a blower and a superheater of the class described, the combination with the superheater tubes, of ballie means including a damper in the path of the furnace gases, steam actuated means attached to the damper and a steam connection between said steam actuated means and the main steam pipe and between said means and the blower said connections being arranged to produce oppositely acting pressures upon said steam actuated means.

4. In a locomotive provided with a blower and a superheater of the class described, the combination with the superheater tubes, of baffle means including a damper in the path of the furnace gases, a pair of piston mechanisms operatively attached to said damper, a steam connection between one piston mechanism and the main steam pipe, and steam connections at opposite ends of the other piston mechanism to blower nozzle and blower steam supply respectively, the connection to blower steam supply being arranged so as to act oppositely, as to the damper, to the connection from the other piston mechanism to the main steam pipe.

5. In a locomotive provided with a blower and a superheater of the class described, the combination, with the superheater tubes, of bafile means including a damper in the path of the furnace gases, steam actuated means operatively attached to the damper, a steam connection between said steam actuated means and the main steam pipe tending to open the damper, a steam connection be"- tween the steam actuated means and the blower steam supply, and a steam connection going from the steam actuated means to the blower nozzle said last named connec tion being open or closed according to the position of the steam actuated means.

6. In a locomotive provided with a blower and a superheater of the class described, the combination, with the superheater tubes, of battle means including a damper in the path of the furnace gases, steam actuated means operatively attached to the damper to open or close the same, a blower, a steam connection to said blower, and means controlled by the steam actuated means for automatically opening or closing said blower steam connection according as the damper is closed or open.

In testimony whereof I have hereunto set m hand.

3 NEAL TRIMBLE MGKEE.

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