US1786828A - High-pressure-boiler installation - Google Patents

Description

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NEW JERSEY, ASSIGZWJHS- TQ XE'TEENATIUNAL COIVIEU$TIGN ETLFGEEEERING (501 i;- POR-ATION, F YLGRK, N. 321, A GGRPOEA'EION OF DELAWARE HIGE-PREfiSUEE-BGILER IldfiTALLATEON Application filed September 17, 1925. Serial 1T0. 806,313.

This invention relates to boiler installations to be operated at high pressures and particularly to pulverized fuel fired installationsin which the boiler is arranged to be its own furnace in association with a boiler unit adapted to withstand high pressures.

Gne of the primary objects of the invention is'to provide a high pressure boiler unit adapted to be associated with a furnace shaped boiler which unit is of simple construction, inexpensive to manufacture, capable of withstanding high pressure with safety, and of such arrangement that a superheater and reheater may be very advantageously coordinated therewithf A specific object of the invention resides in providing a boiler unit of the character described in which relatively thin walled drums, for the high pressure to be carried, ma be employed with safety.

a nother object of the invention is to provide an arrangement of tubes in a boiler unit of the character described whereby slagging and circulation difiiculties are minimized.

More generall it is an object of the invention to provlde a relatively simple and effective boiler with superheater and reheater of economical construction, adapted for use in power generating installations employing high pressure and low pressure engine or multistage engines.

How the foregoing, together with such other objects and advantages as may hereinafter appear, or are incident to our invention, are

- realized is illustrated in preferred form in the accompanying drawings, wherein- Fig. 1 is a vertical section thru an installation embodying our invention.

Fig. 1a is a fragmentary View illustrating a modification providing a gas oiftake at the to Fig.2 is a fragmentary plan section taken on the'line 2-2 of Fig. 1 with the parts he ond the plane of the section being omitted.

hi 3 is a fragmentary plan section taken on e line 3+3 of Fig. 1 with the parts he ond the plane of the section being omitted.

Fig. 4: is a fragmentary vertical section taken on the line 4-4 of Fig. 1.

Fig. 5 is an enlarged cross sectional view of the upper drum of the boiler unit shown in Figure 1, and F l+ig. 6 is a development of the drum of Referring now more particularly to Fig. 1 of the drawings, the installation illustrated comprises, in general, a combustion chamher A, burner meansB of any preferred type for introducing finel "divided fuel such as pulverized coal into t e combustion chamber to be burned in space therein, an ash pit C, and a boiler. unit D, adapted to withstand high pressures, located across the ofitake'E of the combustion chamber.

The combustion space of the boiler is largely defined by steam evaporatin surfaces subject to radiant heat. As here s own, the front of the combustion space above the burner means B is defined by a row of boiler tubes 7, the rear, below the boiler unit D, by a row of boiler tubes 8, the sides by the sets of tubes 9 and 10 which are connected togather by means of a header 11, andthe top by means of a row of tubes 12. The tubes of these rows are preferably finned and they are spaced so that the fins substantially abut. A row of tubes 13 extends across the bottom portion of the combustion chamber and the tubes of this row are spaced sufiiciently widely apart to allow gravitating ash to pass upwardly from the rear to the front of the combustion chamber. The header 15 is connected with a header 16 thereabove by means of tubes 17. The tubes of the front row 7 are connected at their lower ends into the header 16 and at their upper ends into a header 18. The top row of tubes 12 are connected at one end into the header 18 and at the other end into the upper drum 19 of the boiler unit D. The tubes of the rear row 8 are connected at their lower ends into theheader 14: and at their upper ends into the lower drum 20 of the unit D.

The boiler unit D comprises, in general, the upper and lower drums 19 and 20 just referred to, and a plurality of tubes21 con-' necting said drums arranged in a manner hereinafter appearing. -A drum 22 may be associated with the upper drum 19 to provide relativelydry steam under any condiand at their upper ends into the connecting header 11 and the tubes of the set 10 are connected at their lower ends into the header 11 and at their upper ends into a header 24.

A plurality of downcomer tubes 25 lead water from the drum 20 to the header 14 and from thence the flow is upward thru the tubes 13, 17,7, 12 to the'upper drum 19. The flow also'is upward thru the sets of tubes 9 and 10 from the header 14 to the upper drum 19, there being a plurality of tubes 26 provided for connecting the header 14 with the header 23 and a plurality of tubes 27 for connecting the header 24 with the drum 19, the particular arrangement of which will be hereinafter described. The rearward tubes of the connecting tubes 21 act as downcomers from the upper drum 19 to the lower drum 20. Referring now to the particular construetion and arrangement of the unit D, it will be noted that the connecting tubes 21 are arranged in groups and in this instance there is illustrate a front group of three rows of tubes a, b and c which are substantially spaced from a central row of tubes d and a rear group of three rows of tubes e, f and 9, also substantially spaced from the central row at. The first two rows of tubes a and b are preferably inclined from the vertical so that they lean toward the combustion space, or stated in another way, they incline upwardly toward the combustion chamber. Thus slagging at the upper ortions of the tubes where the gases enter t e passes of the unit is prevented and a more positive circulation in the tubes is provided because the tendency will be for steam bubbles to rise to the rear of the tubes, i. e., the portion of the tubes away from the combustion chamber;

instead of to the front. and in this manner the tubes will have greater relieving capacity. i

The tubes of the rows a, b and 0 have their upper portions so disposed that they may be connected into four rows of tube holes in the upper drum, as will be clear from the follow- 1 ing description, and the lower portions of these tubes are so disposed that they may be connected into two rows of tube holes in The tubes of the second row I), however, are more closely spaced say, for example, on 6 inch centers, altho it is to be noted that at their upper portions the tubes divide into two rows, every other tube comprising one row Y and the remaining tubes comprising theother row. Two rows of tube holes 6 and b are provided in the upper drum into which the tubes are secured, the holes of one row being staggered with relation to the holes of the other row. By such an arrangement it will be seen that tube ligaments are provided in the drum which are very materially greater than would be provided if the tubes were connected into a single row of holes spaced on 6 inch centers. The tubes of this row at their lower portions are divided into two rows adapting them to be connected into holes in the lower drum alternating with the tube holes for the row of tubes (1 and for the row 0.

The tubes ofthe third row 0 are preferably spaced on centers corresponding to the cen ters of the first row and are secured in a row of holes '0 in the upper drums, the tubes of the row 0 being staggered with relation to the tubes of the row a. The tubes of the remaining rows 0?, e, f and g, are preferably spaced on centers corresponding to. the spacing of the first row a, and the connecting holes in the upper drum for these tubes are arranged in rows 0?, e, f and g.

The tubes of the roof wall 12 of the coinbustion chamber are spaced on relatively close centers, say for example 6 inch centers, and in order to provide substantial tube ligaments where they connect into the upper drum 19 each alternate tube at itsend portion adjacent the drum is bent so that they may be connected into two rows of tubeholes 12 and 12 in the drum, the holes of said rows being widely Spaced apart and ar rangedin staggered relation.

The tubes 27 for connecting the headers 24 V to the drum 19 also have their end portions adjacent the drum divided into two rows for connection into two rows of tube holes 27 and 27" which provides an arrangement giving very substantial tube ligaments for the drum. It is pointed out that inasmuch as the holes of the rows 27' and 27" are not shown arranged in staggered relation the bent por- ,tions 27 of the alternate tubes will, inaddition to being bent upwardly, have to bend sidewise to register with holes of the row 27".

Other rows of holes h and i are provided in the upper drum for connection of the tubes 21 and 21 leading from the drum 19 to the drum 22.

From the foregoing it will be seen that an arrangement of tubes and tube holes is pro- 1 vided whereby very substantial tube ligaments are provided in consequence of which relatively thin walled drums may be employed for the high pressures to be carried. It has been found for example that in an installation designedfor 1400 pounds pressure with a inch drum the Wall of the drum will safely carry such pressure it it be made as thin as 2 inches, while heretofore walls as thick as 5% inches'or more had to be employed to ensure safety under similar con;

. is provided between the front group of tubes and the central row of tubes (Z in which space a superheater F is located and a substantial space 29 is provided between this central row of tubes and the rear group of tubes in which space a reheater G is located.

Suitable naming/is provided for the unit to provide a plurality of passes for the gases of combustion thru the unit D and in this instance a bafie 30 is arranged at the rear of the front group of tubes which balile extends from the lower drum 20 to a point short of the upper drum 19, a bafile 31 is associated with tubes of the central row (Z and extends from the upper drum to a'point short of the lower drums and a battle 32 is arranged at the front of the rear group of tubes and extends from the loweridrum to a point short of the upper drum. Thus it will be seen that the gases pass downwardly over the superheater, upwardly over thereheater, and then downwardly over and amongst the tubes of the rear group, this last pass being formed in part by the rear Wall 33.

Our invention is particularly useful in connection with high pressure steam turbines for the reason that, owing to the small number of tubes employed in the unit D, the

superheater will be subjected to high heat and the amount of heat abstracted by the tubes of the unit and by the superheater will not be suflicient to reduce the temperature of the gases passing over the 'reheater to a degree where the reheater will be ineffective for the purpose intended.

It will be seen from the foregoing that not only have we provided an arrangement whereby the superheater and reheater will operate effectively but ample space is provided for them and a simple unit is produced which will safely withstand very high pressure without employing thick drums.

The boiler is economical in construction and the drums altho thin-walled are rela- 3 tively small and are, therefore, relatively inexpensive to make. 7

In Fig-1a we have illustrated a modification in which a top ofitake 33a for the gases is provided. A. cross baflle 33b is provided extendin from the bafile 32 to rear wall 33. With such an arrangement the rows of tubes f and 9 act more eficiently as water downtalies.

We claim:

1. In a high pressure boiler installation, a combustion chamber largely defined by radiant heat tubes the amount of evaporating surface of which is such that all of the steaming capacity of the installation is developed thereby; an outlet for said chamber; a relatively small boiler unit in said outlet, said unit comprising an upper and a lower drum each of which is small relative to the pressure carried; a bank comprising a relatively small number of riser tubes connecting said drums, and a second bank comprising a relatively small number of downcomer tubes connecting said drums, said banks being spaced apart; a'superheater and a'reheater in said space; the amount of evaporating surface presented by said riser tubes being approximately ,just sufiicient to lower the temperature of the gaseous products of combustion to protect the superheater and reheater elements against excessive temperature; and means for introducing the fuel to be burned into the lower partoi the combustion chamber.

2. In a high pressure boiler installation, a combustion chamber largely defined by oradiant heat tubes the amount oi evaporating surface of which is such that substantially all of the steaming capacity of the installation is developed thereby; an outlet for said chamher; a relatively small boiler unit in said outlet, said, unit comprising an upper and lower drum each of which issmall relative to the pressure carried, a bank comprising a relatively small number of riser tubes connecting said drums, and a second bank comprising a relatively small number of down-comer tubes connecting saiddrums, said banks being spaced apart, the tubes of the riser bank being arranged in rows in the longitudinal direction of the drums and the upper drum having tube holes for said riser tubes arranged in rows in the longitudinal direction of the drum, there being more rows of tube holes than rows of riser tubes; a superheater and areheater in the space between said banks, the

amount of evaporating surface presented by said riser tubes being approximately just suflicient to lower the temperature of the gaseous products of combustion to protect the superheater and reheater elements against excessive temperature, and means for introducing fuel to be burned into the lower part of the combustion chamber.

3. In ahigh pressure boiler installation, a combustion chamber largely defined by radiant heat tubes the amount of evaporating surface of which is such that substantially all of the steamin ca acity of the installation is developed t ere y; an outlet for said chamber; a relatively small boi1er unit in said outlet; said unit comprising an upper and lower drum each of which is" small relative to the pressure carried, a bank comprising a relatively small number of riser tubes connecting said drums, and a second bank comprising a relatively small number of downcomer tubes connecting said drums, said banks being spaced apart, the tubes of the riser bank being arranged in rows in the 1011- gitudinal direction of the drums and the upper drum having tube holes for said riser tubes arranged in rows in the longitudinal direction of the drum, there being more rows of tube holes than rows of riser tubes; a superheater and a reheater in the space between said banks; the amount of evaporating surface presented by said riser tubes being approximately just suiiicient to lower the temperature of the gaseous products of combustion to protect the superheater and reheater elements against excessive temperature; certain of the aforesaid radiant heat tubes having upcomer connection into the upper drum with the points of connection into said drum arranged in such spaced relation as to provide substantial tube ligaments in said drum; and means for introducing fuel to be burned into the lower part of the combustion chamher.

4. In a high pressure boi er installation, a combustion chamber largely defined by ra-' diant heat tubes the amount of evaporating surface of which is such that substantially all of the steaming capacity of the installa tion is developed thereby; an outlet for said chamber; a relatively small boiler-unit in said outlet, said unit comprising an upper and lower drum each of which is small relative to the pressure carried, a bank comprising a relatively small number of riser tubes 40 connecting said drums, and a second bank comprising a relatively small number of downcomer tubes connecting said drums, said banks being spaced apart, the tubes of the riser bank being arranged in rows in the longitudinal direction of the drums and the upper drum having tube holes for said riser tubes arranged in rows in the longitudinal direction of the drum, there being more rows of tube holes than rows of riser tubes" a superheater and a reheater in the space etween said banks; the amount of evaporating surface presented by said riser tubes being approximately just suflicient to lower the I temperature of the gaseous products of combustion to protect the superheater and reheater elements against excessive tempera-' ture; a dry steam drum connected to said upper drum by a plurality of tubes; and means for introducing fuel to be burned into .60 the lower part of the combustion chamber.

In testimony whereof we'have' hereunto signed our names.

JOSEPH B. CRANE. LEONARD J. MARSHALL.

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