US1261393A - Feed-water heater. - Google Patents

Description

J. B. HUNTERH FEED WATER HEATER.

APPLICATION FILED AUG-2. m5.

Patented Apr. 2, 1918.

7 RN k E /v/ N w 1 s i 1 k I m 6 H m. E 1 m A w m an err JAMES B. HUNTER, 0F DAYTON, OHIO, ASSIGNOB 0F ONE-FIFTH TO GEORGE W. HUNTER, ONE-FIFTH T0 JOHN Gr. COLLISON, ONE-IEIFIH TO FRANK W. KREHBIEL, AND ONE- FIFTH TO GEORGE E. EASTMAN, ALL OF DAYTON, OHIO.

FEED-WATER HEATER.

To all whom it may concern: I 7

Be it known that I,,JAMES B. HUNTER, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Feed-Water Heaters, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to feed water heat ers and more particularly to a comblned feed water heater and accelerator. The primary.

object of the invention is to provide a feed water heater of such a character that it will be applicable to locomotive boilers, as well as to other oilers of various kinds, and W111 raise the feed water to a relatively high temperature before it'entersthe boiler, thereby increasing the eificiency of the boiler and reducing the amount of fuelnecessary to maintain the boiler at its maximum efficiency. As is well known the introduction of cold or relativel cool water into a steam boiler is highly 0 jectionable because it not only reduces the elficiency of the .boiler by temporarily cooling the water therein and re ducing the steam supply but it also results in unequal expansion and contractlon of the parts which, in turn, quickly causes leakage. Various heaters have been provided for heating the water before it enters theboiler and while some of these have a high eficiency they are not applicable to locomotive boilers and they are of an expensive construction. It has been proposed heretofore to provide a feed water heater in whichthe feed water could be mixed with live steam from the boiler, and thus heated to a comparatively high temperature before it entered the boiler. These devices have, however, as far as I have been able to ascertam, been 1mpractical and have not gone into use. One

of the principal difficulties encountered was the incrustation of the heater due to the deposits precipitated from hard water. These deposits accumulated to such an extent that they quickly choked up the heater. 1 v j i It is, therefore, acfurther object of the invention to so construct" and arrange the several parts of the heater that the incrustation due to deposits from hard water will be reduced to a minimum; and, further, to so Specification of Letters Patent.

i the feed water into the boiler.

Patented Apr. 2, 1918..

construct and arrange the parts of the heater that the steam will not only heat the feed water but will accelerate its movement to- .ward the boiler, thereby assisting the injector, pump or other device used for forcing It is also an object of the invention to so construct and arrange the device that it will be automatic in its operation, andwill not onlystart and stop without attention on the part of the operator but will also adjust itself to any variation in the amount of water supplied thereto.

In the accompanying drawings, Figure 1 is a side elevation of a boiler showing my invention applied thereto; and Fig. 2 is a longitudinal sectional View taken through the heater with a part of the heating chamber broken away.

In these drawings I have illustrated one embodiment of my invention and for the purpose of illustration have shown the same as applied to an ordinary horizontal steam boiler but it will be understood that it is applicable to various types of boilers and that the arrangement shown may be varied to accommodate the same to varying circumstances. I

In these drawings the boiler is shown at 1 and is provided with the usual steam dome 2. A feed water line 3 leads to the boiler and has interposed therein an injector a of ordinary construction which is operated by steam from the. boiler, it being for this purpose connected with the steam dome by a pipe 5. While I have shown an injector of ordinary construction as the means of supplying the feed water to the boiler it will be understood that a pump or any other suitable device can be used for this purpose, it being only necessary that the water shallbe supplied to the heater, as hereinafter described, under a proper pressure.

In carryingout my invention I have interposed my combined feed water heater and accelerator in the feed water line between the injector and the boiler. The device as here shown comprises a water nozzle 6 which is connected with the feed water pipe 3 and has a reduced discharge opening arranged to discharge a jet of water into a heating Gun! 'chan'lber. This heating chamber may be oi? any suitable character, but is preferably of a diameter considerably greater than the diameter of the jet of water from the water nozzle and is here shown as coil of pipe 7 the discharge end oi which is connected with the boiler, as shown at 8. Means are provided whereby the jet of water which is discharged from the water nozzle 6 will, .during its passage to the heating chamber, be enveloped in a j at of steam which will lreep the water out of contact with the walls of the device. In the present construction I have provided steam nozzle .9 connected means oil a pipe 10 with the steam dome and havii ig a tapered portion 11 surrounding and spaced away from the water nozzle to form a condensing chamber about the latter. The discharge end of the stea n nozzle 6X? tends some distance beyond the discharge end of the water nozzle and is provided with a passageway 12 ot' a diameter slightly greater than the diameter of the discharge opening .of the water nozzle. This passage forms a conducting passage or chamber through which the steam and water are discharged into the heating chamber 7. Preferably, this conducting chamber is of uniform diameter for a portion of its length, but has that end adjacent to the heating chamber flared slightly. The space 12 between the conducting chamber and the end of the water nozzle may be characterized as an accelerating chamber. The steam nozzle being in open communication with the boiler, through the steam dome, is of course subject to'the pressure. of the steam within the boiler and this steam being partially condensedin the condensing chamber, by its contact with the water nozzle 6, acquires a high velocity so that when it passes the discharge end of the water nozzle it has a velocity greater than the velocity of the jet of water. Inasmuch as the condensing chamber completely s11 rrounds the water nozzle it will be apparent that the jet of water will be completely enveloped by the jet ofsteam, which, of course, will be hollow. Consequently, the jet of steam will carry the jet of water alon with it and the movement of the latter will be accelerated. Thus the steam nozzle combines within itself the functions of condensing the steam, focusing its energy to cause it to be discharged at a high velocity, and accelerating the water by its contact with the rapidly moving steam. The device is so constructed that the intermingling of the steam and water prior to their introduction into the heating chamber will be reduced to a minimum and will be confined to the outer surface of the water jet. This is accomplished by so, constructing and arranging the water nozzle and thesteam nozzleas to prevent the establishment of cross currents. For this purpose the discharge end of the nozzle is provided with a water passage 13 of substantially uniform diameter which causes the water jet to be discharged in a substantially cylindrical rforni anclprevents any ma ,terial spraying of the water. The tapered P r ion o the steam nozzle is shown as iterminating on a line substantially coincident with theiend of the water nozzle. That portion of the steam nozzle which extends beyond the water nozzle is provided with an annular shoulder ll which constitutes an obstruction to the passage of the jet of steam which, when discharged from the condensing chamber, is converging upon the jet of water. The jet of steam is thus prevented from intersecting the of water and no serious cross currents are established. The shoulder or obstruction may be formed in *arions ways but I have, in the present instance, formed the conducting chamber 12 ot' a tube which fits snugly within the end portion of the steam nozzle and the end of which forms the annular shoulder of that nozzle. Preferably, this shoulder is adjust able to accommodate the device to varying conditions vand to this end I have shown the tube as screwthreaded as shown at ll into the end of the steam nozzle.

W hen the boiler is under steam pressure and the injector is operated to cause a jet of water to be discharged from the Water nozzle (3 the steam Within the condensing hamber of the steam nozzle will be partly condensed and will be discharged past the end of the water nozzle at a high ve' ocity. The amount of steam in the chamber is much in excess of the condensation and this excess steam surrounds and completely nvelope the jet of water which is discharged from the nozzle. The water thus kept out of contact with the walls of the steam nozzle and conducting chamber and is carried through the conductin chamber 12, which slightly larger than the discharge end of the water nozzle, at an increased" speed due to the greater velocity oi? the stean'i. The heater thus acts as abooster for the injector o pump and by relieving the latter of part of its work enables it to operate satisfactorily under more widely varying conditions than it otherwise would do. Due to the hape and arrangement of the parts described the jet of steam will not inter-mingle with the et'of water and there will be but little mixingof the water and steam in the nozzle and conducting cham: ber. Consequently, there will be but a small precipitation of deposits and these deposits will, for the most part, be prevented. from reachlng the walls of the device by the en'- veloping jet of steam. AS a result there will be no incrustation 0f the device such as would prevent its successful operation. The

chamber and because of the greater diameter of this chamber are there intermingled, the length of the chamber preferably being such that there will be a thorough intermingling of the steam and water and consequent heat ing of the water before the latter is discharged into the boiler. The precipitation of foreign matter in the relatively large elongated heating chamber will not readily obstruct the passage of the fluids through the same, and the inc-rustations are more easily removed from the heating chamber than from the boiler.

As will be noted the operation of the device is wholly automatic. It requires'no manipulation of valves and no adjustments either to start, stop or regulate the same. A check valve 15 prevents the steam from passing to the injector when the latter is inoperative. As long as no water is passing through the water nozzle there is little or no condensation in the condensing chamber and the steam will acquire no velocity. As soon as the water begins to flow through the nozzle condensation takes place and the steam is discharged from the condensing chamber in such a manner as to surround the water jet and to accelerate its movement.

It has been found by tests in actual service on a railroad locomotive that when the steam temperature in the boiler is 370 F. the feed water will be heated by my heater to 320 F. prior to its discharge into the boiler. The high temperature of the feed water at the time it is discharged into the boiler practically prevents the unequal expansion and contraction of the parts of the boiler. The device is of particular advantage on railroad locomotives because the conditions under which they operate are such that it is frequently necessary to inject large quantities of water into the boiler and when these are not provided with a water heater, this Water i necessarily cold or at best only partially heated. A railroad locomotive, the boiler of which it had been necessary to calk daily, has since the installation of my heater thereon been operated for periods as long as three weeks without being calked, the conditions under which the locomotive operated being the same in both instances.

Further, the raising of the feed water to a high temperature before it enters the boiler materially increases the heating efficiency of the boiler and makes a saving in the amount of fuel consumed. The saving of fuel actually takes place in spite of the fact that live steam is used to heat the water, it having been demonstrated in actual service that a locomotive equippedwith this device used from eight to ten tons of coal on a run which prior to the installation of my heater required from thirteen to fifteen tons, the mileage and tonnage be ing, of course, the same in both instances.

This was partly an indirect saving because boiler ills were cured by the use of the heater, and partly a direct saving because the heater increased the heating efiiciency of the boiler. This increase in eiiiciency and decrease in the amount of fuel required is due to the fact that the process of heating water to a given temperature by conmction gains in eiiiciency as the temperature of the water to be used rises above that of its maXimum density. Vater when continuously heated at a uniform rate from the freezing point at first contracts and then expands at a rapidly increasing rate, the co-eiiicient of expansion of the Waterinoreasing as the temperature rises above the maximum density. Water acquires more rapidly heat which causesgreater expansion because its diathermancy is increased at the higher temperature. A greater rate of expansion causes more active convection currents, and the more active convection currents increase the rate at which heat is taken up from the boiler surfaces because more water to be heated is brought into contact with the heated surface in a givenlength of time. The more active convection currents in turn tend to break up or diminish the thickness of the non-conducting film of water which adheres to the heated metal surface, and, consequently, the heat resistance caused by this water film is diminished. Consequently, a less amount of heat is required to raise the temperature of the water a given number of degrees at a high temperature than to raise the temperature a corresponding nunr ber of degrees at a lower temperature. The rate at which the heat is taken up from the heated surface of the boiler, by convection, increases rapidly with the rise in temperature of the water in contact with that surface and when the water is kept at a high temperature by the use of the feed water heater the more active convection currents which result take in more rapidly the heat created by combustion. The heat thus ac quired more rapidly at the higher temperature of the water in the boiler is transferred without material loss to the feed water in the heating chamber. Therefore, a larger percentage of the heat derived from the fuel becomes transformed into power available for use in the engine and a very material gain in heating efliciency is made.

While I have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited to the details of construction shown and described, for obvious modifications will ocour to a person skilled in the art, and I further wish it to be understood that the construction and arrangement of parts herein shown and described actually produce the results stated regardless of the accuracy of the theories advanced.

Having thus fully described iny invention, what I claim as new a-nddesire to secure by Letters Patent, is:'

1. In a deviceof the character described, a water nozzle having an orifice, a steam nozzle surrounding said water nozzle and forming therewith a tapering condensing chamber, an accelerating chamber iorinii'ig a continuation of said steam nozzle in front of said water nozzle and of a diameter greater than said orifice, an annular shoulder in front of said Water nozzle and lyin in the path of the steam issuing from said condensing chamber, a heating Oliall'ibl', ind a conducting chamber of a diameter g1 t'er than said orifice lying to the rearof said shoulder and connectlng said accelerating chamber with said heating chamber. q

2. In a device of the character described,

a Water nozzle having an orifice, a steam nozzle surrounding said water nozzle and in the path of the steam issuing from said condensing chamber.

in a device or the character easel-m, a tapered water nozzle having a1'1 e1o11g1tted orifice oruniror ia diameter, a tapered steam nozzle su'iround'ii'i g said water name and forming therewith a tapering condensing chamber, a 'lieati'iig chamber, a cylindrical accelerating chamber of a anie ter greater than the "diameter of said orifice and :torininga continuation o f said steam nozzle in front of said water nozzle, an annular -shoulder spaced from said water nozzle and lying in the path of the steam from said condensing chamber, and a reduced assagewa having a portion of uniform diameter andof a diameter greater than the diameter of said orifice lying to the rear of said shoulder and connecting the accelerating chamber with the heating chamber.

1-. In a device or the character described, a Water nozzle having an orifice, a steam nozzle surrounding said Water nozzle and folining therewith a tapering condensing chamber, a cylindrical accelerating chamber of uniform dian'i'eter forming "a continuation of the steam nozzle in front of said water nozzle and of a. diameter greater than the orifice or said water nozzle, a heating chainber, and a conducting chainberhaying a portion of uniform diameter less than the diameter of said accelerating chamber and of a diameter greater than the orifice of said te'r nozzle and connecting said accelerating chamber with said heating ch'a1i1ber. g

Iii testimony whereof Iafiii; my. signature.

v JAMES B. HUNTER.

Copies of this patent may be obtained for five' cents each, by addressing the Commissioner of Patents,

Washington; D. G.

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