US406756A - Car-heating apparatus - Google Patents

Description

2 sheets-sheen" 1.`

(No Model.)

1C. F. MURDOGK.

GAR HEATING APPARATUS. y No. 406,756. Patented JulyQ. 1889.

1519. l .,IAIH..

SUPPLY PIPE FRM LcM/VE 7'0 T/V 'n N PETERS. Hlomulhngnphur. Wuhmgkm, D. C.

?A Sheets-Sheet 2.

(No Model.)

l o. F. MURDOCK. GAR HEATING APPARATUS.

Patented July 9, `1889ii WITNESSESZ N. PEYERS. Plmm-Liumgnyher, wnshingmn. D. C.

UNITED STATES l PATENT OFFICE.

CHARLES F. MURDOCK, OF DETROIT, MICHIGAN.

CAR-HEATING APPARATUS.

SPECIFICATION forming part of Letters- Patent No. 406,756, dated July e, 1889.

Appear@ ned cette 29,1888. seria no. 289,401. (no man.)

siding at Detroit, in the county of Wayne and State of Michigan, have invented certainA new and useful Improvements in Car-Heating Apparatus, of which the following is a speciication, reference being had therein to the accompanying drawings.

My invention relates to that class of systems which, in the heating of railway coaches or cars or other compartments by hot water, employs an apparatus consisting of a boiler, which acts as a digester, and supply, radiating, and return pipes extending into, through, and from said compartments, and a forcepump; and it consists, primarily, in the provision of such means as will indicate to the operator deviations from the normal and proper working of the apparatus, so that the same may be again restored to its normal and proper action before the occurrence of damage.

In the practical operation of such a system an obstacle to the proper working thereof isV found in the formation of water-hammer in the pipes of the systenn'often resulting, especially in cold weather, in the cracking and breaking of the pipes.

My invention is designed to overcome and remedy this defect by the following described means.

I describe and show herein my improvement used in conjunction with apparatus for heating railwaycoaches; but it will be seen that the device may be used i`n a like system with like results in heating any character of compartment.

I preferably use the boiler of the locomo-- tive as the source of supply, providing arsuitable pressurereducing valve, hereinafter described, said valvebeing at a point on the side of theV boiler below the waterfline, and a pressure-indicating gage, which will indicate to the operator the pressure at which the water leaves the boiler on the discharge side of said valveinto the supply-pipe,which latter eX- tends rearwardly into the train, said pipe and the return-pipe of the system being formed in sections secured to each of the coaches and connected by suitable flexible hose and couplings in any well-known manner. To the end .with a suitable gage.

of the return-pipe, near the point where the Water is to be returned for reheating, is located and secured an air-expansion chamber (into which said return-pipe opens) provided The return-pipe is connected at a point on its length near the expansion-chamber to a pump by means of a branch connecting-pipe, which affords communication between said pipe and pump/the latter forcing the return-water through its discharge-pipe into the boiler for reheating, or into the tank, from whence it may be fed by an injector or inspirator, in the usual man'- ner, into the boiler again. The pump and air-chamber may be located relatively to one another upon such a part of the locomotive as may be found most convenient.

In the accompanying drawings, Figure l represents a side elevation of the pump and airexpansion chamber, also showing the gages and portions of the pipes of system. Fig. 2 is a side elevation of a loco-motive and aportion of a passenger-coach, showing the air-chamber, reducing-valve, and pump attached to the locomotive, and the system of supply and return pipes, the arrows indicating the direction in which the water circulates. Fig. 3 is a detail sectional view of the pressure-reducing valve.

A designates a pump of suitable construction connected with the locomotive-boiler A', Fig. 2, by means ofdischarge-pipe B, through which the water will be pumped into the boiler or tank after having circulated through the train. u

C represents the supply-pipe, which extends from the locomotive-boiler A rearwardly into the coaches, and D represents the returnpipe, which extends from the t-ailend of the train, the said pipes C and D being con-l nected at the tail end by any suitable coupling-pipe.

The extremity of the supply-pipe C is so disposed at c as to open communication into the boiler A below the water-line thereof, and has interposed in its length near said boiler a pressure-reducing valve G, constructed and operated as follows, reference' IOO passing through the auxiliary valve CZ, which is held Vopen by the tension of the spring e, passes down through the port f, underneath t-he differential piston g. By raising this piston the valve h is opened against the initial pressure, since the area of 7L is only one-half of that of g. Vater is thus admitted to the low-pressure side, and also passes up the port fz', underneath the phosph or-bronze diaphragm j, upon which bears the spring` e. When the low pressure in the system has risen to the required point, which is determined by the tension of the spring e, the diaphragm j is forced upward by the water in -the chamber k, the valve d closes, no more water is admitted under the pistou g, and the valve h is forced onto its seat by the initial pressure, thus shutting off water from the low-pressure side. This action is repeated as often as t-he low pressure drops below the required amount. The piston CZ is fitted with a dash-pot, Z, which prevents chattering or pounding when the high or low pressure suddenly changes.

The degree of pressure admitted is regulated by the adjustment of the tension of the spring e by means of rod-connection e', as re` quired, in accordance with the indications of a pressure-indicating gage F, which' has comto connect and establish communication between t-he return-pipe D and the pump A. The expansion-chamber is provided with a suitable pressure-indicating gage I.

m is a stop or cylinder cock, through which the air in the pipes of the system finds a means of escape from in front of the advancing column of water.

The operation of my improved apparatus and the means by which the hereinbefore-described obstacle is overcome are as follows: WVhere the length of pipe through which the hot water circulates is short or the external temperature moderate, or the hot water is driven through short lengths with great velocity, water-hammer may not form in the pipes; but where longer length of pipe is used or the pressure lconsiderably reduced hammer is likely to occur. In order to overcome this formation of water-hammer, it is necessary that the water should circulate continuously as such under all conditions throughout the whole length of the pipes of the system, and in order to accomplish lthis result it is necessary that the pump should not be permitted to act as a suction upon the water in the pipes, but should merely pump and force the same into the boiler or tank. Since the water necessarily leaves the high-pressure boiler at a temperature which, if the pressure upon said water admitted through the pressure-reducing Valve were removed or reduced to a lminimum, the said water would be immediatelyv converted into steam, it follows that if the pressure were so reduced or removed at a point in the length of the pipes of the system where t-he temperature of said water was passing from 212o Fahrenheit to a temperature below said degree a port-ion of the advancing column of water above 212o Fahrenheit, depending as to extent upon the amount of pressure withdrawmwould at such a point be converted into steam, which latter, passing along through the pipe, would be condensed into water, forming a water-hammer.

If the pump should act to produce or cause suction in the return-pipe, the pressure would be removed from in front of the advancing column of water therein, and the advancing column of water above 212O Fahrenheit at a point in the pipe where the said water was passing to a temperature below 212o Fahrenheit would be converted into steam for a portion of its length proportionate'to the amount of pressure removed by the suction of the pump, which steam would be condensed by the cooler portion of the pipe into water, forming water-hammer.

By the interpositon of the air-chamber between the pump and the return-pipe the ordinary and normal operation of the heating system is indicated to the operator by the existence of pressure within the said chamber, as shown upon gage I, in which case the pump is performing its proper workn-viz., to force the water through its discharge-pipe; but when the pump runs so rapidly as to create a suction within the return-pipe the air in the expansion-chamberlbecomes rareied and the gage I will show the absence of the usual and requisite pressure, which, being thus indicated, the speed of the pump may be checked by the operator. So, also, whenever the pump shall be run so slowly as to fail to force the water rapidly enough out of its discharge-pipe the water in the return-pipe would gradually enter the expansion chamber, increasing by condensation the pressure, which fact being indicated upon the gage I, the operator may increase the speed of the pump. The gages F and I thus serve to indicate to the operator the necessity of either increasing or decreasing the speed of the pump or increasing or cutting off pressure in the specified exigencies.

It will be understood that I do not claim the form of reducing-valve shown, nor a system of supply, radiating, and return pipes, nor an air-expansion chamber, broadly; but,

f Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is the following:

The combination, in a hot-water-heatin g apparatus for car-heating, of a high-pressure boiler or heater, a pressure-'reducing valve having an indicating-gage, an air-expansion chamber provided with an indicating-gage,

IOO

said chamber being secured to and having In testlnonywhereof Iaxmysgatule in communication with the end of the returnpresence of two Witnesses. pipe of the radiating system, and L branch 7 connecting-pipe secured to Ishe said return- Y CHARLES F MUBDOM' 5 pipe n ear said chamber and affording commufitnessesz nicaion between said returlnpipe and a foree- XV. H. SANFORD, pump, as described. J. L. LANE.

Images