US2212542A - Compact adjustable boiler superheater - Google Patents

Description

` Aug. 27, 1940. w. A. JONES y COMPACT ADJUSTABLE BOILER SUPERHEATER 2 Sheets-Sheet l l p llllllflilllilllllllllllll..Illllllllll ..//JJ A mvENToR COMPACT ADQTUSTABLE OILER SUPERHEATER Filed Feb. 28,71938 2 Sheets-Sheet 2 1.-? rl` l' F16, 7 FIG I i fly/luga g 15| lul Patented Aug.27,' 1940 ooMPAc'r ADJUSTABLE nonna SUPER- HEATER Williaml Anthony Jones, Port Richmond, N. Y. Application February 28, 1938, Serial No. 193,034

y4 claims.

My invention is a development of the adjustable boiler superheater for which United States Patent No. 1,929,532 was granted to me Oct. 10, 1933, which dominates this.

This development occupies less space.

Lines 60 to 68 of page l of that patent state:

For ratings below that at which the resistance of vapor flow through a foot of height of the coil is'less than the pressure due to a foot of height of the liquid, several coils operating in parallel will tend to distribute 4the flow equally between them and the rate of iiow for them all can be determined by the difference in pressure governed by one thermostatic valve.

The fact that the resistance of flow, per foot of length of tube, is a function of the density and of the square of the velocity, results in this re-` sistanoe being very much less for the Water heating length and for the evaporating length than for the superheating length of the tube.

This permits more length of tube and more coils per foot of height in the water heating surface and per foot of height in the evaporating surface than per foot of height in the superheating surface. This results in less total height for a given service. 4.

The tubes of two or more concentric helixes tend to shield the upper and lower surfaces of the tubes from contact with the hot gas.

Making the center line of one helical coil offset from the center line of another helical coil of any one element, reduces this shielding of the upper and lower surfaces of the tubes except where the tubes cross each other. One right hand helix and one left hand helix may be put together side ways, horizontally, after being formed, and brought to a position` where the centers of the helixes are the required disltance apart, even when the pitch is greater for the vapor` heating surface than for the liquid 'heating surface and for the evaporating surface. Two right hand helixes or two left hand helixes of any one element may be formed together at one time and tlien moved so that their centers together or taken apart after being formed if the pitch of the water heating surface or the steam drum and float valve, corresponding to Fig. 1 of Patent No. 1,929,532.

Fig. 2 is a view, looking horizontally, showing are apart, but'evidently they can not be put` an element formed of one right hand and one left hand helix.

Fig. 3 is a sectional view, looking horizontally at 90 degrees from the direction of looking at Fig. 2, also `of an element formed of one right 5 hand and one left hand helix, with their centers apart. v

Fig. 4 is a view like Fig. 3, but not in section.

Fig. 5 is a part plan view of four elements as described and of the headers to which they con- 10 nect.

Fig. 6 is a part plan view, partly in section, with .single tube helixes having more length of tube per foot of height in the lower part than in the upper part, otherwise similar to Fig. 6 15 of United States Patent 1,929,532.

Fig. 7 is a part plan View, partly in section, with two tube helixes with centers offset, and otherwise corresponds to Fig. 7 of United States Patent 1,929,532.l 20

Fig. 8 is a part plan view of four tube helixes, alternately right hand and left hand and with their centers oiset so that the longitudinal pitch of the overlapping parts of one helix will slope the same as the overlapping part of the helix 25 above and of the helix below, thus permitting a minimum pitch of each helix, about four times the diameter of the tube.

Fig. 9 is an enlarged part plan view of one right hand helix and one left hand helix, other- 30 wise as described for Fig. 8 and permitting a minimum pitch of about two times the diameter of theltube.

Like reference characters indicate like parts inthe several views. 35

In the compact adjustable boiler superheater shown, which I have chosen for purposes of illustration, feed pipe l supplies liquid to a float valve 2, maintaining level 3 of liquid in container 4. 40

A spring |00 may support partof the weight of float valve 2, which must be heavy to be strong enough for present day high pressures.

A horizontal part 5 supplies liquid to headers 6, from which liquid flows to lower ends 8 or 8 45 of helixes 9 or 9.

Upper ends of helixes 9 are connected to headers Il, which discharge into drum I2 at o' side of thermostatic valve I3, whose function it is to maintain such a pressure in the steam space I4 50 at one side of the thermostat valve I3, above the pressure in the space I5, above the float valve 2, as will cause the level I6 of the liquid in the helical coils to be sufficiently below the level 3 `to give the required superheat.

The thermostatic valve i3 is represented as formed of the following parts;

A plate Il with hub I8 slides on feed pipe l.

A spring i9 is on the pipe l between the hub i8 and a second hub 2l which is attached to the pipe.

A plate 23 is fastened to the shell of the vapor drum I2 by bolts 24;.

Circular grooves 25 and holes 26 are formed in plate l1, and circular grooves 2l and holes 28 are formed in plate 23.

With a space 25 between the plates ll and 23, vapor can pass through the valve from space llt to space i5.

Feed pipe l, whose temperature is limited to about that of the liquid feed to the boiler does not expand endwise as much as does the drurnv l2 with increase of temperature, with the result that as the drum grows longer, with increase of temperature, the plate 23 moves with respect to the hub 22, so that at a deiinite temperature the space 29 between the plates is increased, thus increasing the valve flow area and limiting the difference in pressure to that which will depress the liquid in the coil just enough to give the required superheating Surface to give the required superheat.

Feed pipe i and hubs 2l and 22 can be moved by diierental screw 3l, so that with the boiler cold the hub 22 will be at -a small distance 32 to the right of the plate il. Stumng box 33 permits pipe l to be moved without leakage.

Set screws 3ft determine the minimum distance between plates ll and 23 and prevent the complete closing of the thermostatic valve. Lock nuts 35 hold these set screws after they are set.

Nozzle 3l above space`l5 of the drum I2, discharges superheater vapor from the boiler.

Drum head 35, held by bolts 39, may be removed giving access to the interior ofthe drum and permitting inner parts of the apparatus to be removed.

U bolts di suspend headers il from beams d2.

Hot gases may ow downward between the helixes or in the reverse direction, but the end of the tube having more length of tube per foot of coil will always be the'cooler end, regardless of whether the hot gases ilow upwardly or downwardly, because the liquid enters the tube at the endA having morev length of tube per foot lof coil and the superheater is at the end having less length of tube per foot of coil.

Valve 55, connected to lower horizontal part 5, may be used for flooding Athe boiler with liquid and for draining liquid from the boiler.

United States Patent No. 1,929,532, page 2, lines to '74 states;

Evidently headers 6 can be supported below helical coils, permitting the coils to be drained if desired without other change.

That is the construction shown.

Provision is made for container d to expand vertically, due to change in temperature, with seal plates ll where headers 5 pass through the wall of the boiler setting, as shown.

I claim:

l. An adjustable boiler superheater having one or more vertical elements each formed of one right hand one left hand helical coil of tube, with their centers offset horizontally, and having more length of tube, per foot. of height, in the lower part than in the upper part, as described, surrounded by hot gas and supplied with liquid at the' lower end and with the upper end discharging vapor into a space in which the pressure is maintained by a thermostatic valve responsive to the temperature of the vapor discharged in said space, thus depressing the liquid within the coils enough to give suiiicient vapor lled surface to give the required outlet temperature of vapor above the boiling temperature.

2. An adjustable boiler superheater having one or more helical coils of tube, having more length of tube per foot of length of coil at its cooler end than at its hotter end, surrounded by hot gas and with a thermostatic valve discharging therefrom controlling the relative pressures at the inlet and at the outlet so that only so much liquid is supplied to one end of'the coil as will be discharged as vapor of the 'desired temperature at the other end.

3. In combination, a vertical helical coil of tube, having more length of tube per foot of height in the lower part than in the upper part, to the lower end of which liquid is supplied, hot gas surrounding the coil and imparting heat to it and a thermostatic valve at the upper end of the coil opening at a temperature above that of the boiling liquid.

4. In combination, a oat valve part of whose weight is supported independent of its buoyancy, a vvertical coil of tube having more length of tube per foot of height in the lower part than in the upper part, receiving liquid from the oat valve, hot gas surrounding the coil and a thermostatic valve at the upper end of the coil opening at a temperature above that of the boiling liquid and maintaining a pressure at the outlet ofthe coil intermediate between that at the oat valve and that at the bottom of the coll.

WILLIAM ANTHONY JONES.

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