US1834214A - Shielded superheater - Google Patents

Description

Dec. 1, 1931. w. D. LA MONT 1,834,214-

SHIELDED SUPERHEATER Filed April 26, 1928 5 Sheets-Shea 1 ATToRNEYs Dec. 1, 1931. w. D. LA MONT SHIELDED SUPERHEATER 5 Sheets-Sheet 2 Filed April 26, 1928 54.. ATTORNEYS Dec. 1, 1931. w. D. LA MONT SHIELDED SUPERHEATER 5 Sheets-Sheet 3 Filed April 26. 1928 III-IIIIFI w 0 mm NM W5 2 M D K m ATTORNEY Dec. 1, 1931.

w. D. LA MONT 1,834,214 SHIELDED SUPERHEATER Filed April 26, 1928 5 Sheets-Sheet 4 Jiya INVENTOR ll/mm 000G045 [Mo/v7- B A A sRNEYj Dec. 1, 1931. w, LA N 1,834,2l4

SHIELDED SUPERHEATER Filed'April 26, 1928 5 Sheets-sheet 5 58 INYENTC R //IL 72% fiqgem; ZA/Vwvr Patented Dec. 1, 1931 UNITED STATES, PATENT OFFICE WALTER DOUGLAS LA MONT, OF LARCHMONT, NEW YORK, ASSIGNOR TO LA MONT COR- PORATION, OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK SHIELDED SUPERHEATER Application filed April 26,

This invention relates-to steam generating and superheating systems and its primary object is to attain a high. efiiciency in steam generation and superheating and, at the same time, insure that the superheater elementsare at no time subjected to a temperature so high that they would be injured thereby.

It is the general practice to use superheater tubes bent somewhat .in the shape of a hairpin, the steam entering at one end and passing through the bent tube being discharged near the same end at which it enters. In boilers of locomotives such tubes are inserted within the fire tubes and while the steam flow through one arm of such a tube is in a direction counter to the flow of the hot gases through the fire tube, the steam flowing in the other arm of the superheater tube is in the same direction as the gas -fiow.. It follows from this arrangement that the steam in the tube near the discharge end thereof is often at a temperature higher than the gases at this point so that some of the super-heat of the steam is re-transferred to the gases and therefore wasted.

In the present invention the superheater tubes run straight through the fire tubes. Vhere such tubes are used in a locomotive or where used, for example, in an upright furduced at the cooler end, the steam flowing in a direction counter to the gas flow. Under such conditions the gas temperature at the steam intake end of the super heater may never be lower than the temperature of the steam at that end and therefore no heat of the steam will be lost to the gases.

Heretofore, however, there has been diifition of a fire tube showing the supporting culty in the use of superheater tubes having one end extending into or near the fire box, on account of the excessive heat to which they r are subjected at this point and the danger of being injured by such heat. According to the arrangement of the present invention, whereby La Mont tubes are extended lengthwise of the gas flow and among the superheater tubes, it becomes feasible to protect the superheater tubes ends in the zone of the'hottest gases and even in the Zone of radiant heat, if such tubes are extended into such zone, by the nace, the steam to be superheated is intro- 1928. Serial No. 272,873.

derstood in connection with the accompany ing drawings, which show in more or less schematic form two practical embodiments of the invention.

Figure 1 is a-longitudinal sectional view taken on the line 11 of Figure 2.

Figure 2 is a section on the line 22 of Figure 1, looking in the direction of the arrows in that figure.

Figure 3 is a perspectiveview showing one of the intake headers with parts broken away to show the jet orifices and tubes.

Figure 4 is a section on the broken section line H of Figure 1.

Figure 5 shows sections of two fire tubes with the steam generator and superheater elements therein.

Figure 6 is a View takenon the line 6-6 of Figure 1 but with the lower portion broken I away to show parts beneath the boiler plate. Figure 7 isa cross section of a fire tube showing one way of supporting the steam generating tubes therein.

Figure 8 is a longitudinal section of a porspace 1b and a smoke stack 1 0.

Leading out from the water space of the boiler is a. water pipe 2, Figures 1 and 2,

which connects with the suction side of a pump 3, preferably of the centrifugal type.

A conduit 4 leads from the discharge side of the pump through a strainer 5 and connection 6 to a distributing manifold 8 through have been described in full in my co-pending which water is supplied to a plurality of. steam generating intake headers 9, each of which is suit bly connected to the manifold in a manner well known in the art.

several elements connected to an individual header.

The elements 10 arsmall in diameter as compared with the diameter of a fire tube so that several may lie alongside each other throughout the length of a single tube.- Four tubes 10 are showninone fire tube in Figure 1 5 right hand view, and also in Figure 7 As 25- shown in Figure 1 the elements 10 extend beyond the fire box' end of the fire tubes a distance which,in practice, is approximately 21 inches," where they enter discharge headers 14,'Figur,es 1' and 6. These headers are closed:

at their lower ends but their upper ends pass throu h the boiler plate 15 and terminate at its upper surface.

. l The amount of water supplied by the pump through the jet orifices in the intake head ers, is in quantity greater than the evaporating capacity of'thetubes or elements 10'.

. Theconditions asto size of the steam generating elements. the velocity of flow and sizeof the jet orifices in order to continuously propagate a film of water along any tube,

" application Serial No. 209,024, filed July 28,

1927. As disclosed therein, the size of the steam generating tubes suitable to effect generation of steam according to the method disclosed in saidapplication' may be about inch diameter, although tubes of somewhat larger or smaller diameters may be used.

lVithout goinginto the details of all the fac- 50 tors involved it is su'flicient for the purpose 'ofthe'. present invention to emphasize the fact that steam and water flow along theste'am generating'elements'from the intake headers9and excess wa ter is de'livered to the discharge headers 'andthis' fact is availed of in the" present 1 invention. to afford protection to the superheaters and superheater elements.

Steam from the boiler; passes through an outlet connection 16to the superheater mani- ,-shown in Figures 1" and 2. This manifoldisin the formofa cylinder very similar to 'thefmanifold 8 for the steam generating elements but omewhat-finger; The superhas: n a e a er gla ma be m i construction the water intake headers 9,

as shown in Figure 3. Each header 19 is connected with the manifold 17 by a nipple 18 and extends vertically in front of the ends of a series of fire tubes.

Leading from each superheater header is a plurality of superheater tubes 20. These may be larger than the generating elements 10, as will be noted from F igures'2 and 5, but not necessarily so. In some cases two super-heater elements may run through a single fire tube as shown. u

In Figure 2 of the drawings it will be noted that the s'uperheater tubes may pass through fire tubes adjacent to those through which the steam generating elements pass but this alternate arrangement of steam generating tubes and superheated tubes is not a necessary arrangement since the number of superheater tubes would depend upon a number of conditions well known in the'art, so thatthe arrangement shown, is merely illustrative of one embodiment of the invention and in no sense limits it to the exact construction shown. The opposite end of each superheater tube extends into a discharge header 21, shown in elevation in Figure 1 and in section in Figure 6. Each of the headers 21 leads to a steam collecting pot 22, Figure 1, from which steam is taken to'the cylinders of the locomotive or to any other point where it is tobe used.

Nipples 21a are arranged between thepot 22 and each discharge header 21, or othersuitable connections might be provided.

For convenience the intake headers 19 are situated between the intake headers 9 and the front boiler plate 19a and are spaced from u the latter a distance at least equal to the distance between the discharge headers 14: and

21.- This construction enables any set of tubes 20 to be moved forwardly to bring the headers 21 sufficiently close tothe lleaders l i also provides an arrangement'of superheater elements so that the heat of the g ases is moist efiiciently utilized in superheating the steam.

Therefore the steam generating ele ments 10 extend beyond the firetubes and into thefire box some distance beyondthesuperheater headers 21 so that the latter and "the ends of the superheater tubes are within the radiant shadow of the steam generatingheaders and tubes. Furthermore,the hot gases' are-in c'on'- tact with the steam generatingheaders and tubes 10 for a suificient lengtl i of time to effeet a considerable reductioninf the temperature of such gases beforefthey come into con:

stantly supplied with water, and some wateris discharged into the headers 14. Therefore, theze headers and the tubes adjacent thereto I will very rapidly absorb heat from the fire and from the gases, and such gases will be quickly lowered in temperature in passing over these headers and tubes.

The gases fiow from the left'to the right in Figure 1 through the fire tubes. lVith the arrangement shown, however, the water for the steam generating elements is introduced into the headers 9 and flows in a direction counter to that of the gases. The steam to be superheated likewise enters the headers 19 and flows counter to the direction of the gases. It results from this arrangement of counterflow that the temperature of the steam at or near the headers 19 is always at or below the temperature of the gases at that point. In Figure 7 an arrangement for suitably supporting the steam generating elements within a fire tube is shown. For this purpose a bracket 25 holds the four tubes in place assisted by a spacer 25a of suitable shape.

In prior constructions there has been, as

far as known to me, no way of attaining completely the advantages of counterflow of steam in the superheater elements, because such an arrangement would necessitate the placement of the superheater headers in or near the fire box where they are necessarily exposed to temperatures greater than they can withstand for long life and low upkeep. \Vith the present arrangement, however, the

steam generating elements and headers afford the necessary protection while preserving the advantages of the counterfiow arrangement. r

In Figure 9, the principle of the invention is illustrated in a slightly different form of apparatus. Here the steam generating elements and superheater elements are arranged in a vertical direction instead of horizontal.

26 represents the lower walls of a supporting structure and 28 the upper walls thereof. The general principle and mode of operation,

.0 however, is the same as in the first described form of invention.v

A pump 29 is provided which forces water through a pipe 30 to the distributing mani-.

fold 31. Leading out from this manifold is a plurality of intake headers 32 shown in cross section in- Figure 9. These headers,

however, may be like those shown in Figure 3 and from each of which leads a plurality of steam generating elements 33, which elements extend vertically or approximately so, to lower or discharge headers 34, the latter connected to a discharge manifold 35 from which which a water return connection 43 leads back to the pot 36. The steam passes up through the steam conduit 44 to the superheater distributing manifold 45, thence by connections 46 and branches 47 to the several intake headers 48 for the superheaters. From these'headers the superheater elements 49 lead to lower superheater discharge headers 50, the steam passing thence through branch pipes 51, connections 52, to the superheater discharge manifold 53 from which it is lead by a steam conduit 54 to the place of use.

A water level control shown diagrammatically at 56 maintains the Water level in the collecting pot 36 through suitable connections 57 acting on the valve 58 in the feed water supply pipe 39.

As in the first described form of the invention the steam generating headers and the lower ends of the steam generating tubes extend such distances below the ends of the superheater tubes and headers that the latter are amply protected from the radiant heat and high temperature gases in the lower portion of the boiler. The same advantages of counterflow are availed of in this form of the invention as have been set forth fully in describing the first form. The gases enter the furnace near the bottom which may also be a zone of radiant heat, the gases passing in the direction of the arrows up through the space between the steam generating and superheater elements, where they pass out through a stack near the top (not shown).

What is claimed as new is:

1. In asteam generator and superheater system, steam generating elements situated in the path of the heating gases and arranged to absorb heat by convection, superheater elements situated among the steam generating elements, intake and discharge headers for said steam generating elements and superheater elements, and means for supplying and distributing water to the steam generating elements through their intake headers in generating elements and superheater elements is counter to the direction of flow of the heating gases, the discharge headers for the steam generating elements being located such distances beyond the discharge headers for the superheater elements that the gases are cooled by contact with the steam generating discharge headers and the steam generating elements before coming into contact with the superheater elements and superheater headers.

2. In combination with a boiler having fire tubes and a firebox, a set of steam generating elements extending through some of said fire tubes and a set of superheater elements extending through some of said fire tubes, headers situated beyond the fire tubes at each end thereof to which a set of steam generating elements and a set of superheater elements are respectively connected. means for introducing water through the headers into one end of each of the steam generating elements in quantity greater than the steam generating capacity of the elements, whereby steam and water are discharged into the'headers at the other end of the sets of elements, and means for introducing steam into the superheater elements through the headers remote from the fire box whereby the steam flows counter to the flow of heating gases, the steam generating elements and headers at the fire box end extending such a distance beyond the superheater elements and headers that the superheater elements and headers are shielded from contact with gases at too high a temperature.

3. In combination with a boiler having fire tubes and a fire box, a set of steam generating elements extending through some of the fire tubes and a set of superheater elements also extending through some of said fire tubes, means for introducing water into the steam generating elements, and means for introduo ing steam into the superheaterelements at their ends remote from the fire box whereby the steam flows counter to the flow of the heating gases, the steam generating elements at the fire box end extending-be ond the superheater element's thereby shielding them from contact with gases at too high a temperature.

4. In combination with a boiler having fire tubes and a fire box, a set of steam generating elements extending through some of the fire tubes and a set of superheater elements also extending through some of the fire tubes, means for introducing water at the end of the steam generating elements remote from the fire box in quantity in excess of the steam generating capacity of the elements and discharging the excess water at the fire box end of said elements, and means for introducing steam into the superheater elements at their ends remote from thefire box whereby the steam flows counter to the flow of the heating gases, the steam generating elements at the fire box end extending beyond the superheater elements thereby shielding them from too high a heat.

5. In a steam generator and superheater system, steam generating elements situated in the path of the heating gases to absorb heat by convection and extending into a zone of radiant heat, superheater elements situated among the steam generating element-s and having portions thereof extending into the radiant heat zone, a header in the radiant heat zone and situated among the steam generating elements to which the superheating elements are connected as a set, and means for introducing steam into the superheater elements in counterflow to the heating gases, the arrangement of the superheater elements and the header in relation to the steam generator elements in the radiant heat zone being such that the superheater elements and the header are situated Within the radiant shadow of the steam generating elements.

6. In a, steam generator and superheater system, steam generating elements of relatively small cross section-situated in the path of the heating gases to absorb heat by convection, superheater elements situated among the steam generating elements, means for positively delivering and distributing the water to the heat absorbing surfaces of the steam generating elements and causing it to flow counter to the flow of the heating gases, and means for introducing steam into said superheater elements so that its' direction of flow therethrough is counterto that of the flow of the heating gases, a portion of the system generating elements being situated beyond the ends of the superheater elements in the direction of the higher heat so that by reason of the absorption of heat by the steam generating elements the gases are cooled to a temperature insufiicient to cause damage to the superheater elements.

7. In a steam generator and superheater system, sets of steam generating elements situated in the path of the heating gases and arranged to absorb heat by convection, superheater lements providing steam superheating surface and so situated among the sets of steam generating elements that a set of steam generating elements is adjacent to a portion of the superheating surface which is in the zone of high temperature, each of the sets having an individual inlet and outlet, and means for introducing steam into said superheater elements so that its direction of flow through said elements is counter to that of the flow of the heating gases, said steam generating elements extending beyond the superheater urface in a direction counter to the flow of the heating gases for such a distance that the gases are cooled by reason of the absorption of heat by the generating elements to a temperature insufficient to cause damage to the superheater elements.

8. In a steam generator and superheater system, steam generating elements of relatively small cross section and superheater elements situated in the path of the heating gases and arranged to absorb heat by convection, means to positively force Water into said generating elements in quantity greater than their evaporating capacity and causing it to flow in a direction counter to the flow of the heating gases, and. means for introducing steam into said superheater elements, said steam generating elements having at least a portion located beyond the ends of the superheater elements in a direction counter to the flow of the heating gases, whereby the gases are cooled by reason of the absorption of heat by the generating elements to a temperature insufiicient to cause damage to the super-heater elements.

Signed at New York, New York, this 19th day of April, 1928.

WALTER DOUGLAS LA MONT.

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