US2964033A

US2964033A - Vertical tube heater

Info

Publication number: US2964033A
Application number: US750170A
Authority: US
Inventors: John W Throckmorton; John S Wallis
Original assignee: YUBA CONS IND Inc
Current assignee: YUBA CONS IND Inc; YUBA CONSOLIDATED INDUSTRIES Inc
Priority date: 1958-07-22
Filing date: 1958-07-22
Publication date: 1960-12-13
Anticipated expiration: 1977-12-13

Description

Dec. 13, 1960 J. w. THROCKMORTON ETAL 4,

VERTICAL TUBE HEATER Filed July 22, 1958 '2 Sheets-Sheet 1 E" /7 17 h .22 /5 Q j- 3; 33 32 fig 2 ma T T T INVENTORS w s. 14441 1 /J BY Dec. 13, 1960 J. w. THROCKMORTON ETAL 2,964,033

VERTICAL TUBE HEATER 2 Sheets-Sheet 2 Filed July 22, 1958 INVENTORS JOHN W. THROC/(MOPTOA/ VERTICAL John W. Throckmorton and John -S.'Wa1lis,New :York,

N.Y., assignors, by mesne assignments, to Yuba Consolidated Industries, Inc., San Francisco, ,Calif., acorporation of Delaware Filed July 22, 1958, Set. N0.'750,170

7 Claims. (Cl. 126-109) This invention pertains to vertical tube heaters having a cylindrical shell, the arrangement of the tubes being such as to make the heater peculiarly well adapted for heating air or other gaseous material, although the heater is susceptible of more general use. Various objectsand advantages of the heater will hereafter appear and will be readily understood by those skilled in the .art.

Referring to the drawings:

Figure 1 is a partially sectional elevation which, for simplicity, omits most of the tubes except those at the vicinity of the cross section.

Fig. 2 .is a sectional .plan view taken on the line of Fig. 1 and, for simplicity, shows :only a small group of the total number of tubes, which are uniformly spaced in a circumferential direction within the heater. The supporting beams for the stack are omitted in this view.

Fig. 3 is a partial view corresponding to Fig. 1 illustrating a type of preheater or economizer section which may be employed to absorb a larger proportion of the heat from the flue gases before they escape into the stack.

In the structure of Figs. 1 and 2, to which special reference may now be had, the furnace shell is preferably a cylinder of large diameter relative to its height, having a bottom plate 11 which supports a group of central burners 12 which may, if desired, be replaced by a single burner and a plurality of outer burners 13 which are spaced in a circle, as shown in Fig. 2.

The furnace shell 10 is supported by a plurality of structural steel legs 14, only two of which are illustrated, and which are welded to the furnace shell 10. A top plate 15 is mounted on the furnace shell near the top and preferably welded thereto. It has a large central opening and carries a concentric cylindrical stack 16. A plurality of structural steel triangular supports 17, only two of which are shown, mounted on the furnace at the top, support the stack 16 and have overhanging lugs 18 which extend a short distance down from the top of the furnace shell and are welded thereto.

A plurality of coils 20, each of which is preferably formed of a single bent tube having a relatively large diameter bend at the top and two parallel legs 21 extend downwardly through the bottom of the heater. The coils are supported from the triangular frame 17 at the top of the heater by hangers 22.

Below the bottom of the heater is a large circular inlet manifold 30 in the form of a hollow torous ring 23 to which all of the outer legs of the coils are connected as indicated at 24. The inner legs are similarly connected to a concentric torous ring 31 of smaller diameter, as indicated at 25.

All of the

burners

12 and 13 are upshot, and the flame and hot gases from the burners 12 extend upwardly in an axial direction through the center of the heater until diverted by conical baifle 32 which is supported by hangers 33 from the top plate 15 of the heater. The apex of the conical baflie is downward and the base of the

cone

2,96i,33 Patented Dec. l3, i960 is at the top and is spaced from the "top plate 15 so that the hot gases eventually flowinwardly and up the stack 16.

The inner legs of :the coils areheated primarily by radiation from the central column of flame and hot gases just described. Additional flames and hot gases rise from the burners 13 between the inner and outer legs of the .coils and largely .give up heat by radiation to the outer side surfaces 'of the inner legs of the coils and to the inner side surfaces of the outer legs of the coils.

The outer surfaces of the outer legs of the coils are largely heated by reradiation from the furnace shell 10, the inner surface of which is preferably provided with a refractory lining 10a. The gases arising from burners 13, after having given up a large part of their heat by radiation, bathe the upper bends of the coils and flow inwardly and up the stack. The inlet manifold 30 has inlet pipes 35 and the outlet manifold 31 has outlet .pipes 36.

The heater is particularly welladapted for heating air .or other gaseoussubstances, since the large inlet and outlet manifolds provide va ready distribution and equalization of thefluid supply to the outer legs of the coils. Like- .wise the outlet manifold is large and insures a good distribution of the highly heated gaseous .substance flowing downwardly through the inner legs of the coils.

It is of special importance that the outer legs of the .coils, which are supplied with the gaseous fluid to be heated, which would normally be at moderate temperature, are heated by radiation only on the inner surfaces and by reradiation on the outer surfaces, since they absorb heat readily due to the great difference in temperature between the flames and the gaseous fluid. On the other hand, the gaseous fluid, which is already highly heated before it enters the inner legs of the coils and flows downwardly, is subjected to intense radiant heat on both the inner and outer surfaces by reason of the burners 12 in the center of the heater and the burners 13 between the legs of the coils.

In Fig. 3 like parts are designated by the same reference characters, and here the conical baffle 32 and supports 33 are omitted, and an economizer coil 40 comprising a nest of tubes with extended surface means thereon largely fills the space in the lower end of the stack and thus increases the efiiciency of the heater by lowering the temperature of the flue gas before it is per mitted to escape up the stanck 16. The nest of tubes which makes up the economizer coil 40 is supported by hangers 41 from cross rods which form a grid 42 without interfering with the upward flow of the flue gases. The economizer has an inlet pipe 43 and an outlet pipe 44. The economizer may be connected with a source of air or gas to be heated prior to its introduction into the inlet manifold 30 of the main heater.

While the heater illustrated and described is well adapted for heating air and the like, it can be built with a very much taller furnace shell and very much longer coils and also, if desired, may be utilized for heating oil or other liquids. The radius bends at the top of the coils are such as to permit the tubes to be bent into the desired shape, and no return bends of the ordinary construction are necessary or employed.

By reference to Fig. 2, it appears that by reason of the difference in diameter between the inlet and outlet manifolds, the outer legs of the tubes 20 are spaced substantially from one another and from the Wall of the heater. This is preferable to enhance the reradiation effects from the refractory lined furnace wall.

On the other hand, the inner legs are close together and the coils are preferably made with alternately wider and narrower spacing between the legs so that they are more readily accommodated at the inner circle where they join the outlet manifold.

Other modifications of this invention may be made without departing from its fundamental aspects, and hence we desire that only such limitations be imposed as are indicated in the appended claims.

What we claim:

1. A heater comprising a vertical cylindrical furnace chamber having a refractory wall, a top plate attached to the cylindrical furnace chamber and having a central flue gas outlet, a bottom plate attached to the chamber at the bottom, a plurality of inverted U-shaped tube units each composed of two widely spaced vertical leg tubes and a large diameter return bend at the top, said tube units being circumferentially distributed around the axis of the chamber in radial planes, hangers supporting the tube units from the top plate so that the outer leg tubes are close to but spaced from the refractory wall of the chamber and from each other and form a single cylindrical bank of vertical tubes and the inner leg tubes are Widely spaced from the outer leg tubes so that the inner leg tubes form a concentric cylindrical bank of vertical tubes which produce an unobstructed interior combustion chamber, the two concentric cylindrical tube banks forming an unobstructed annular combustion chamber, at least one central burner in the bottom plate adapted to discharge flame and hot combustion products into said unobstructed interior combustion chamber and a circle of burners in the bottom plate adapted to discharge flame and hot combustion products into said unobstructed annular combustion chamber formed between the two concentric cylindrical tube banks whereby heat is applied by direct radiation on both sides of the inner bank of vertical tubes and on the inner side of the outer bank and by reradiation fromthe refractory wall of the furnace chamber on the outer side of the outer bank, and interconnecting means for the tubes near the bottom of the furnace.

2. The furnace structure of claim 1 in which concen tric manifold rings to which the outer and inner vertical tube banks are respectively connected constitute the interconnecting means.

3. The furnace structure of claim 2 in which the concentric manifolds are disposed below the bottom plate and the tube banks extend through the bottom plate to connect therewith.

4. The furnace structure of claim 1 in which an inverted conical baffie is centrally mounted near the top of the furnace chamber.

5. The furnace structure of claim 2 in which an inverted conical bafiie is centrally mounted near the top of the furnace chamber.

6. The furnace structure of claim 1 in which a flue or stack extends vertically upward and is mounted on the top plate at the flue gas exit.

7. The furnace structure of claim .1 in which a flue or stack extends vertically upward and is mounted on the top plate at the flue gas exit and an economizer disposed therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,524,637 Ruegg Oct. 3, 1950 2,725,873 Walter Dec. 6, 1955 2,789,521 Wasp Apr. 23, 1957 2,796,052 Throckmorton et al June 18, 1957