US 688084 A
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Description (OCR text may contain errors)
N0. 688,034. Patented Dec.. 3,` l90|.
. E. H. GLD.
(Application led Feb. 1, 1900.) (nu Model.)
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EGBERT H. GOLD, OF CHICAGO, ILLINOIS.-
SPECIFICATION formingpart of Letters Patent No. 688,084, dated December 3, 1901. Application filed February 1', 1900. Serial No. 3,607. (No model.)
5 and State of Illinois, have invented certain new and usefullmprovements in Steam-Traps,
of which the following is a specification.
This invention relates to improvements in steam-traps especially designed for use in con- Io nection with the steam-'heating systems on railway-cars, such traps being connected with the steam-pipes and located outside of and generally below the car-body in such manner that they will automatically open and close for the purpose of discharging the water of condensation from the steam-heating pipes y as rapidly as it forms.
The class of steam-traps to which inyinvention particularly relates are those in which zo an expansion device readily responsive tothe eifects of heat and cold is employed to operate a valve controlling the exhaust-port from the steam-pipe, this class being exemplified in Letters Patent No. 492,495, granted to me on the 28th day of February,l893. All such traps are liable to prove unsatisfactory and more or less sluggish in action, because the water of condensation is thrown upon or against the expansion device in its discharge through 3o the trap, and as its temperature increases with the flow the expansion device is affected almost as soon as the discharge commences,
and the result is a gradual closing of the dis-v charge-port valve, which in some instances is 3 5 completely effected before all of the Water of condensation is discharged from the steampipes and in other instances is very slowly effected and is frequently so sluggish as to keep the valve almost constantly open, and
4o thus cause a constant drip from the trap,
which is exceedingly objectionable in any railroad service, and particularly on elevated railroads. Furthermore, in severe climates during intensely-cold weather, whether the valve closes too' soon, and thus imprisons the water of condensation in the trap,or whetherit is so sluggish as to practically never close tight, and thus keep up a constant drip with a body of water of condensation always in the trap,
5o there is always danger of the water of condensation freezing in the trap or in the pipe leading to the trap, and this is particularly true of such traps as have their valves located outside of the car-body or space to be heated, of which there are numerous types in general use. The loss of time, loss of service of the car, expense, and loss of labor resulting from the freezing up of the trap are well understood by those familiar with this art; and one of the primary objects of my invention is to avoid all such danger by having the trap of such construction that the freezing up thereof is rendered practically impossible, no matter how the trap may be constructed and designed to operate. y
A further primary object of my invention is to so promote the sensitiveness of the trap that it will remain wide open until practically all of the Water of condensation has been discharged and then will close almost instantly by isolating and protecting the expansion device from contact with the Water of condensation during its discharge from the trap.
Another object of my invention is to protect the expansion device against the wear or ffwiredrawing caused in active service by the constant balancing of valves of this class in which the diaphragm of the expansion device is seated directly on the valve-seat.
These and such other objects as may hereinafter appear are attained by the devices illustrated in the accompanying drawings, in which Figure l represents a vertical section through a portion of the vertical type of trap described and claimed in the above-mentioned Letters Patent, showing my invention applied thereto. Fig. 2 is a vertical section through a horizontal type of trap having my invention applied thereto; and Fig. 3 is a view similar to Fig. 2, showing another form of horizontal trap.
Similar letters of reference indicate the same parts in the several figures of the drawings.
In Fig. 1 I have shown the lower end only of the patented vertical type of trap hereinbefore referred to, in which A indicates the outside tube for the blow-off discharge, B the inside tube, through which the water of condensation is discharged, C the apron on the outside tube to direct the course of the blow-off of the discharge, D the casing for the expansion device, and F the hinged cover IOO for the casing D, all of which parts are found in the aforesaid patent.
The expansion device E is in the nature of a thin double-walled diaphragm containing an expansible iiuid and is connected `by the valve stem or rod G with a valve on the npper end thereof (not shown) controlling the exhaust from the steam-pipe, which valve is automatically operated by the expansion device in a manner that is now Well understood in this art. The water of condensation, which is discharged through the inner tube B, passes through the trap-casing D and is discharged to the atmosphere through the openings H in the cover for the casing.
The essentially novel feature of my invention is the imperforate shield I, which is located immediately above the expansion device, is 'preferably secured to the rod G in any suitable manner and is of a diameter greater than the expansion device and sufficient to insure the shedding of the water of condensation which falls thereon beyond the expansion device, with which the water of condensation is thereby prevented from coming in contact in its passage through the casing. It will be noted that there is a small space between the shield I and the expansion device, the edges of which latter are preferably turned down to more readily shed the water, and hence even though the Water of condensation may be quite warm the heat thereof will not be suiiicient to materially affect the expansion device, because it does not come in direct contact therewith; but as soon as thesteam-vapor begins to enter the casing D, at which time practically all of the Water of condensation has passed out of the pipes, the expansion device will be instantly aected thereby and cause a prompt and almost instantaneous closing of the valve operated by theA expansion device. It will thus be seen that the automatically-operated valve by reason of the presence of-my shield is kept practically wide open as long as it is desirable to have it so and is almost instantly closed as soon as such closure becomes desirable, thus rendering the trap as a whole exceedingly sensitive and quick in action and insuring its closure always at the proper time and Without the liability of imprisoning any of the water of condensation in the steampipes after the iiow once starts, a result of the utmost'importance in a device of this class.
With the vertical type of trap above described the danger of freezing, even though water be imprisoned in the steam-pipes, is practically eliminated by reason of the peculiar construction of the trap, which places the control -valve within the space to be heated; yet even with this structure I find the action of the valve is frequently more or less sluggish, because as soon as the Water of condensation strikes the expansion device the valve begins to close, thus throttling the discharge-port and sometimes causing a drip csepa from the trap for an unnecessary length of time. In the horizontal type of trap, however, (illustrated in Figs. 2 and 3,) the liability to freezing is always present, because the trap and a vertical drop from the steam-pipes is generally located outside of and beneath the car, and as in practice it is common to use in connection with this style ofv trap a blow off valve located in the drop pipe where the water of condensation may accumulate it is all important that the accumulation should be eliminated. In the form of valve shown in Fig. 2 the trap-casing D has a discharge-opening I-I on the under side thereof, and the expansion device E itself acts as an automatic valve by seating directly upon a suitable valve-seat J, surrounding the opening through which the Water of condensation enters the trap-casing. This trap is now extensively in use just as shown in the drawings, with the exception of the shield I, interposed between the expansion device and its valve-seat. Where the shield is absent, the water of condensation as a matter of course must strike directly against the expansion device in its discharge from the steam-pipes, and all the objectionable results heretofore pointed out arise therefrom; but by interposing the shield I, which may be placed directly against the expansion device, as shown in the drawings, or indirectly by the interposition of some suitable packing-disk, the Water of condensation will strike against the shield and fall to the bottom of the casing, from whence it escapes through the opening Il Without coming in contact with,
and thereby affecting, the expansion device,
While as soon as the steam-vapor enters the casing it will pass around the shield and instantly affect the expansion device, with the same result as hereinbefore mentioned. In valves of this construction there is an almost constant slight opening and closing of the valve. Obviously Whenever the valve is closed the contents of the diaphragm become quicklycooled,thediaphragmcontracts, the valve opens, live steam escapes, expands the contents of the diaphragm, seating it upon the valve-seat and closing the valve again. This constant vibration and the action of the steam escaping through the slight opening between the valve-seat and the face of the diaphragm when the valve is open results in what has come to be known as Wiredrawing, whereby the face of the diaphragm adjacent to the valve-seat is worn in a circle immediately adjacent to the valve-seat until the diaphragm is destroyed. As these diaphragms are quite expensive and this wearing or Wiredrawing is rapidly brought about in active service, vit is of practical importance to, if possible, avoid this destructive action. It will be seen, therefore, that in addition to promoting the efficiency and sensitiveness of the trap my shield when used in traps of the construction shown in Figs. 1 and 2 absolutely protects the diaphragm against IIO this wiredrawing, for in my improved construction of this form of trap the shield and not the diaphragm is seated upon the valveseat, and the -action of the valve and of the escaping steam results in wearing or wiredrawing this shield, which when worn past the point of efficiency may be readily replaced and being simply a thin disk of sheet metal may be replaced at slight expense. By the use of my device, therefore, the life of the expensive diaphragmisincreased many fold.
In the construction shown in Fig. 3, which is a device of the horizontal type of novel construction,which I shall describe and claim in another application filed of even date herewith, the expansion device E is located in a separate chamber K of the' trap-casing D from that in which the valve L, controlling the discharge-port from the steam-pipes, is located, the chamber M, in which the valve L is located, being provided with an opening H, corresponding to that in the casing shown in Fig. 2, through which the Water of condensation is intended to be discharged without entering the chamber K, in which the expansion device is located, which chamber has discharge-openings N therein for the purpose of dischargingthe condensed vapor as well as any water of condensation which may be driven into said chamber. Of course by lengthening the connection between the chambers K and M, as shown and described in my aforesaid application, where such construction is possible, the expansion device can be isolated with certainty from the Water of condensation; but in many cases it is not practicable to have the casing of such length, and in such cases, where the valve and the expansion device must be close together, as shown in Fig. 3, there is liability of some of the water of condensation being driven through the chamber M and into the chamber K, containing the expansion device. Vith such a construction by placing my shield in front of the expansion device any Water of condensation that may be driven intotheexpansion-chamberwillstrikeagainst the shield and fall to the bottom of said chamber, from whence it will escape through the opening N, thus effectnally protecting the expansion device against the action of the water and the results arising therefrom, while at the same time leaving such device free to be instantly aected by the steam vapors which pass into saidchamber and around the shield.
It will thus be seen that in all forms of steam-traps shown in the drawings the shield is interposed between the expansion device and the port leading from the steam-pipe to which the trap is secured; that the expansion device is eftcctually protected and isolated by the shield from contact with the water of condensation; that the action of the trap is ren dered exceedingly sensitive, remaining open as long as it is desirable and closing almost instantly when closure is desirable, and that the addition of the shield to the form of traps shown in the drawings or any otherforrn of trap to which it is applicable adds but very little to the cost of the trap, while greatly increasing the practical and commercial value thereof and giving it capabilities which it has never previously possessed and producing an advantageous result that is most important in this art.
While I have herein shown and generally described the expansion device as being a double-walled diaphragm containing some liquid readily responsive to the effects of heat and cold, such devices being now very generally used in this art, obviously my invention is equally applicable to any other form or construction of expansion device,whether it contain an expansive liquid or not-such, for instance, as common forms of metallic or tubular expansion devices. Furthermore,while I have described and shown the shield I as an imperforate shield I do not desire to limit myself to such a shield only, because in some instances,and especially in very cold climates, it might be desirable to slightly perforate the shield or otherwise permit a small portion of the Water of condensation to come in contact with the expansion device sufficient to raise the temperature of the expansion deviceconsiderably above that of the atmosphere and yet not above the point where expansion would take place, such a refinement of my invention being merely for the purpose of rendering the expansion device more quickly responsive to the effects of the steam-vapor when it begins to flow. This will be readily appreciated when it is understood that a tein-4 perature of 175C to 180 is generally necessary to cause any expansion to take place in the expansion device, and that therefore the temperature of the expansion device may be safely raised to about 150, which would thus cause it to respond much more quickly when the steam begins to flow. Such a change would simply increase the sensitiveness of my device, while at the same time the shield would serve to prevent contact with the expansion device of the principal part of the water of condensation, which would produce the bad effects hereinbefore referred to. Indeed, a part of this eect, and possibly the Whole of it, may be produced by the conduction of heat from the shield to the expansion device by contact, as illustrated in the drawings, Without the necessity for any such small perforations. It is therefore obvious that my invention contemplates all such changes as do not depart from the spirit of my invention.
Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-
l. The combination with a steam-trap comprising an expansion device, of a shield, located in said trap adjacent to said device, for preventing contact with said device of the water of condensation in its passage through Ice the trap,and lneans for freely admitting steam to immediate contact with said expansion device, substantially as described.
2. The combination witha steamtrap cornprising an expansion device and avalve automatically operated thereby to control the discharge opening from the steam pipe, of a shield interposed between said valve and the expansion device, and means for allowing steam to substantially surround said eXpansion device, substantially as described.
3. The combination with a steam-trap com-