US1780300A

US1780300A - Heat-transfer device

Info

Publication number: US1780300A
Application number: US103443A
Authority: US
Inventors: David S Jacobus; William A Jones
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1926-04-21
Filing date: 1926-04-21
Publication date: 1930-11-04
Anticipated expiration: 1947-11-04

Description

Nov. 4, 1930.

D. S. JACOBUS El AL HEAT TRANSFER DEVICE Filed April 21. 1926 1 l I I I a o I I Wham ..u..... .2

INVENTOR passes to the steam and water drum through.

Patented Nov. 4, 1930 UNITED STATES PATENT; OFFICE DAVID s. .mcoiaus, or monrcnnm, NEW J RSEY, AND WILLIAM A.. JONES, or WEST 0 NEW nnrenrou, NEW ronxnssmnons 'ro THE BABCOGK & wrncox comrnmr, or-

BAYONNE, NEW JERSEY, A.- .COBPOR ATION OF JERSEY Application fi1ed.Apri1 '21,

Our invention will best be understood from the following description and the annexed drawings of an illustrative form of apparathrough a portion of Fig. 1 and Fig. 3 is a detail sectional view illustrating one of the tubes of the air heater and its connections to the end plates.

In the arrangement illustrated in Fig. 1, the boiler is of a well-known type, in which the horizontally inclined water tubes 10 are connected to uptake and downtake' headers which, in turn, are connected to a transverse steam and water drum 11, the boiler having a furnace 12.

From the boiler the gases pass upward through a ban'kof tubes 15 constituting 'a vertical economizer to which water is preferably introduced through a lower header 15iby connections, not illustrated, and which a pipe 18.

The gases on passin from the vertical economizer enter a cham er 19 through which water, or, if desired, a substantially non; volatile liquid, such as oil, as determined by operating conditions is sprayed, this water or other liquid being introduced thereto through a pipe 20, and from this washing,

. chamber the water may flow to a settling tank with means for repumping the same, this tank and repumping means not being shown. When the water is circulated over and over again, a re-agent toneutralize the acid fumes absorbed by Water may be added. From the chamber 19 the gases flow to a chamber 21, in which is installed an, air heater, the heated air from which may-be utilized in any suitable manner, preferably by being returned to the combustion chamber, so that the heat of the flue gases is returned to the boiler system. In the embodiment illustrated, the air heater comprises an upper plate or head 32 and a lower plate or head 33, between which extend a plurality of tubes 34, so that the flue gases from the cham- HEAT-TRANSFER DEVICE 1926'. .Seria111o.,103,443.

ber 19 will pass downward through the tubes 34 into the'gas outlet, a' forced draft fan 29-preferably being employed to force the gases into the outlet flue 31. The air to be heated enters at the side of the air heater through the duct 35, and passes around the end of a baffle 36 and through the outlet duct 37, the air thereby flowing in a generally upward direction through the air heater, whereas the hot flue gases pass downwardly through the tubes 34, thereby providing a counterflow between the heating gases an the heated air.

Above the head 32we provide a spraying device by means of which. the interior surfaces of the tubes 34, which are the surfaces contacted by the hot flue gases, may be 1 .washed and also, if desired, sprayed with protective coating material. In the illustrative .embodlment, such a spraylng arrangement is illustrated by a tube 38 extending hor1zont ally'across the chamber 21, the tube 38 being provided with nipples each over one of the tubes 34. The spray tube 38 is mounted in a carriage 39 so that it may be moved laterally across the chamber 21 by means of a rack and pinion operated by the chain 39, the tube 38 having a hose connection 40. Since the tubes 34 are arranged in rows, it is obvious that by moving the tube 38 laterally and bringing it to rest over successive rows, the nipples on the tube 38 may be brought over all of the tubes 34, one row at a time.

By supplying water or steam through the hose 40 and the spray tube 38, the interiors of the tubes 34 may be washed or cleaned so as to remove any tar or soot which may have collected in them.

In the illustrative embodiment of our invention, the bottom ends of the tubes are so connected to the bottom plate that when there is relative expansion or contraction between the tubes, as through cleaning theinterior thereof by means of suitable cleaning elements, the tubes can slide through the lowermost plate without causing an undue amount of strain.

The upper plate 32 is preferably supported as the lower plate and the shell in which the heater is located. The upper ends of the tubes are secured in the openings of the top plate preferably by expanding the ends of the tubes therein, while thelower ends of the tubes are freely slidable in the openings 41 in the lower plate, as illustrated in Fig. 3, the lowermost ends of the tubes below the plate 33 preferably being flared, as at 42, to a diameter greater than the diameter of the openings in the plate 33. The lower plate 33 is thus supported on the lower ends of the tubes, and is preferably made flexible, particularly when the same is made as a continuation of a wall of the flue 35, as illustrated in Fig. 2, to avoid an undue amount of strain in case the tubes contract, particularly from the washing or cleaning operation. By securing the tubes at their upper ends to the upper plate 32 and permitting them freely to slide through the openings of the lower plate there is no tendency to bend the plates under the expansion and contraction of the tubes.

' At the same time, the tubes secured to the upper plate serve to maintain said plate in horizontal alignment. The upper plate is pref erably made comparatively thin, and if the tubes were loose therein, would tend to sag at its middle portion due to the weight of the parts.

. to said plate, any sagging of the top plate would necessarily throw the tubes secured thereto out of vertical alignment. But since the tubes are held in vertical alignment through their slidable connection in the lower plate the upper plate cannot sag. "It will thus be seen that the tubes act as web members to a girder of which the upper tube sheet forms the upper flange, and the lower tube sheet the lower flange. may thus be made comparatively thin and cheap, and in practice we have found that we can advantageously make the plate as thin as three-fourths of an inch or even one half inch, and so thin that the plate would sag were it not forthe fact that it is kept horizontal through the action of the tubes in the manner above described.

While claims herein are intended to cover broadly not onl the illustrated embodiment wherein the tu es are supported from the upper plate, but a construction wherein the tubes are secured to the lower plate and are slidably received in the upper plate, this last specific construction is the invention of William A. Jones and no specific claim thereto is made herein. In case the tubes were secured'to and supported from the lower plate, it will be understood that supporting members for the lower plate which could be similar to those here shown for the upper plate, would be provided.

We claim:

1. In an air heater comprisingaplurality of rows of vertically extendingtubes,asingle up- But when the tubes are secured The upper sheet per and a single lo'wer plate each provided with openings through which the upper and lower ends respectively, of the tubes pass, the tubes being secured at one end to a first of said plates and the other ends thereof being slidably received in the openings of the second plate, and associated means for supporting 'said second plate on said tubes, the plate to which said tubes are secured being of such a thickness that its own weight and the weight of the tubes secured thereto would normally cause said plate to sag substantially.

2. In an air heater comprising a plurality of rows of vertically extending tubes, a single tubes secured thereto would normally cause I said plate to sag substantially.

3. In an air heater com rising a plurality of vertically extending tu es, a single horizontally extending upper and a single horizontally extending lower, plate parallel to said upper plate, each plate being provided with openings through which the upper and lower ends, respectively, of the tubes pass, a. casing rectangular in cross section joining said plates and forming aflue in which the air heater is placed and through which flue gases pass, the upper ends of the tubes being secured to the upper plate and the lower ends thereof being slidably received in the openings of the lower plate whereby said tubes prevent the upper plate from sagging, and associated means for supporting said lower plate on the lower ends of said tubes.

4. In an air heater comprising a plurality of rows of vertically extending tubes, horizontally extending plates provided with openings through which the upper and the lower ends respectively of the tubes pass, the upper ends of the tubes being secured to the upper plate, and the lower ends thereof being s idably received in the openings of the lower 6. In an air heater comprising a plurality of rows of vertically extending tubes at least 180 in number, horizontally extending rectangular plates provided with openings through which the upper and the lower ends, respectively, of the tubes pass, a first of said plates being not more than three-fourths inch in thickness and supported at its edges, the tubes being secured to the first plate and freely slidable in the openings of the other plate whereby the tubes serve to prevent the first plate from sagging;

7. In an air heater comprising a plurality of vertically extending tubes at least 180 in number, horizontally extending rectangular plates provided with openings through which the upper and the lower ends respectively of the tubes pass, the upper plate being not more 1 than three-fourths inch in thickness and supported at its edges, the tubes being secured in the upper plate and freely slidably in the lower plate whereby the tubes serve to prevent the upper plate from sagging. I

8. In combination, a vertically extending flue for conducting hot gases, an air heater located therein and comprising platesprovided with openings extending across said flue, and tubes secured in the openings of the upper plate and slidably received in the openings of the lower plate, the entire sliding engagement being formed between the metal of the tubes and the metal of the sheet, the tube ends beneath the lower plate being flared to a diameter greater than the tube openings of the lower plate.

' 9. In combination, a vertically extending flue for conducting hot gases, an air heater located therein and comprising plates provided with openings extending across said flue, and tubes secured in the openings of the upper plate and slidably received in the openings of the lower plate, the tube ends beneath the lower platebeing flared to a diameter greater than the tube openings of the lower plate, the lower plate being flexible whereby it accommodates itself to variations in expansion and contraction of the tubes.

10. In combination, a vertically extending flue for conducting hot gases, an air heater located therein and comprising plates extending across said flue and each provided with openings, tubes secured in the openings of the upper plate and slidably received in the openings oi the lower plate, the tube ends beneath the lower plate being flared to a diameter greater than the tube openings of the lower plate, and means for applying a liquid successively to interior surfaces of said tubes.

11. In combination, a heat exchange device comprising upper and lower spaced plates each provided with openings, tubes secured in the openings of the upper plate and slidably received in the openings of the lower openings of the lower plate, and means for applying a liquid successively to surfaces of in the openings of the other tube sheet, the I slidable joints between the tubes and the tube sheet in which they are slidable being formed L only between the metal of the tubes and the r metal of the tube sheet, the plate to which said tubes are secured being of such a thickness that its own weight and the Weight of the tubes secured thereto would cause said plate to'sag substantially in the absence of preven-' tive means.

1% In an air heater, a single upper and a single lower tube sheet each provided with openings, a plurality of tubes, at least 180 in number, secured at one end in the openings of the upper tube sheet, and at their other ends slidable in the openings of the lower tube sheet, the slidable joints between the tubes and the lower tube sheet being formed only between the metal of the tubes and the metal.

of the tube sheet, the upper plate to which said tubes are secured being of such a thickness that its own weight and the weight of the tubes secured thereto would cause'said plate to sag substantially in tive means.

15. In a fluid heater, a plurality of vertical- 1y extending tubes, upper and lower plates provided .with openingsin which the upper and lower ends of said tubes are received, the

tubes being secured at one end to a first of said plates, means for supporting said first plate, at least some of said tubes being provided with means located beneath the other plate for supporting the latter.

DAVID S. JACOBUS. WILLIAM A. JONES.

plate, the tubes beneath the lower plate being flared to a diameter greater than the tube the absence of preven