US1966388A

US1966388A - Water tube boiler

Info

Publication number: US1966388A
Application number: US489833A
Authority: US
Inventors: Harter Isaac
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1930-10-20
Filing date: 1930-10-20
Publication date: 1934-07-10
Anticipated expiration: 1951-07-10

Description

July 10, 1934. HARTER 1,966,388

- WATER TUBE BOILER Filed Oct. 20, 1930 2 Sheets-Sheet l INVENTOR saac H a/rter ATTORNEY July 10, 1934; AR ER 1,966,388

WATER TUBE BOILER Filed Oct. 20, 1930 2 Sheets-Sheet 2 INVENTOR 1 Isaac Hm *Em Fa am ATT RNEY Patented July 10, 1934 UNITED STATES PATENT OFFICE WATER TUBE BOILER Application October 20, 1980, Serial No. 489,833

' 9 Claims (c1. 122-302) This invention relates to water tube boilers, and. more particularly to an arrangement of tubes for such boilers.

An object of the invention is to provide a steam boiler of the type set forth having the tubes thereof arranged so as to produce greater ligament strength in the boiler drum for a given number of tubes than has heretofore been possible for the same thickness and diameter of boiler drum.

Other objects will be apparent to those skilled in this particular art from the description in the specification in connection with the drawings, in which- Fig. 1 is an end view of a section of the drum and tube banks; I

Fig. 2 is a view at right angles to Fig. 1 taken along the line 2-2;

Fig. 3 is a view at right angles to Fig. 1 taken along the line 33;

Fig. 4 is a view at right angles to Fig. along the line 44;

Fig. 5 is an end view similar to Fig. 1 showing a modification of the invention;

2 Fig. 6 is a view at right angles to Fig. 5 taken along the line 6-6;

Fig. 7 is a view at right angles to Fig. 5 taken along the line 77;

Fig. 8 is a View at right angles to Fig. 5 taken along the line 8-8.

The particular embodiment of the present invention which has been chosen for the purpose of illustration is shown in connection with a steam boiler of the Stirling type having two upper drums 1 connected by steam and water circulators 2 and 3 respectively, and having banks of tubes connected therewith.

In order to produce the greatest ligament strength possible in the drums between tubes, the present invention provides an arrangement in which the tubes of any given longitudinal row are connected with tube holes in the drum which are spaced apart a greater distance, longitudinally, of the drum than the tubes themselves.

1 taken The tube holes are arranged so as to permit a plurality of tubes of a given longitudinal row to be connected to a plurality of tube holes arranged in a single circumferential row in the drum.

As illustrated in Figs. 1 and 3, the first two longitudinal rows of tubes 4 in the front bank of the boiler are grouped and connected by suitable connectors with tube holes in the drum. These tube holes are spaced apart longitudinally, a dis- I tance equal to three times the distance between the separate tubes of a longitudinal row so that the ligament between the tube holes longitudinally is at least three times what it would be in a drum having the same number of tubes connected thereto in the usual way. Each adjacent pair of tubes 4 in the two front rows of the first bank is connected by Y fittings 6 to a single connector 8 joining the fitting to the associated drum, as shown in Fig. 1.

Each group of three connectors 8 is expanded into three tube holes located in a single circumferential row in the drum as shown in Fig. 3, and it will be apparent that each circumferential row of tube holes is spaced longitudinally from the adjacent rows a distance equal to three times the 7 distance longitudinally of the drum between adjacent connectors 8, resulting in a large increase in the ligament strength of the drum over that which would be obtained if the tubes 4 were connected directly to-the drum in the usual manner, or that which would be obtained if the connectors 8 were connected directly to the drum in the same longitudinal row.

. The tubes 5 forming successive rows of the front bank are connected to the drum in a slightly so different way which, however, produces a similar advantageous increase in ligament strength. As illustrated, in Figs. 1 and 4, each pair of tubes 5 in adjacent rows is connected by Y fittings 6' to connectors 7 leading from the fittings to the 5 drum. Alternate connectors [are bent so as to enter the drum through tube holes'located in the same circumferential row as the tube holes connected to the intermediate connectors, as shown in Fig. 4. As a result of this arrangement the longitudinal ligaments in the drum are materially greater than would be the case if the tubes 5 and connectors 7 extended directly to the drum in the usual manner.

Tubes '9 are arranged as risers connecting water walls (not shown) with the front drum 1.

In order to provide for the greatest possible ligament strengthbetween the tube holes in which the risers are expanded, pairs of riser tubes are bent to enter the drum through holes located in the same circumferential row, the arrangement being such that single intermediate riser tubes, located between each of such pairsof tubes, are connected to the drum in the usual manner, as

illustrated in Fig. 2. It will be apparent that this results in a considerable increase in the ligment strength. a

In the modifications shown in Figs. 5 to 8 similar results are accomplished by more or less similar arrangements, the difference in construcdrum a distance greater than the distance be-' tween successive connectors 18 of a given row, and the tube holes are arranged in different circumferential rows so as to accommodate all the connectors of a given row within the length of such row. As illustrated in Figs. 5 and '7, the difierent connectors 18 are bent to enter tube holes in the same circumferential row with adjacent connectors so that the ligaments between holes of adjacent circumferential rows are materially greater than the distance between the respective connectors 18.

Each pair of tubes in the subsequent rows of tubes 15 in the front bank is connected to Y fittings 16 which are connected by connectors 17 to the drum and it will be apparent that the use of the Y fittings in connection with pairs of tubes in a single longitudinal row provides an arrangement in which tubes of a given row are expanded into half the number of tube holes, again resulting in increased ligament strength. The risers 19 from the water walls are connected to the drum in the same manner as the risers 9 heretofore described.

The tubes of the

banks

5 and 15 are normally spaced and given such a size and surface as are most suitable for external conditions incident to absorbing heat from the passing gases, and when so proportioned are usually of greater internal cross sectional area than is needed for the flow of water through them. Under such conditions it is permissible, so far as internal circulation is concerned, to reduce the flow area at the upper ends, and highly desirable to do so by means of this invention in the interests of the drum. Joining the drum to each pair of tubes by one smaller tube and the Y fittings, reduces the required hole size and number in the drum. This permits an increase of ligament strength between holes, or a reduction of drum thickness, or a reduction of drum diameter, or any two of these or all three of them.

Although I have described the invention as applied to the front bank of tubes of a Stirling type of boiler it will be apparent that it is equally applicable to banks of tubes in other locations and to various other types of vapor generators. It will also be apparent that the present invention is independent of the use of the I fittings which have been described in connection with the particular embodiment illustrated in the drawings,

that the invention is equally applicable to boilers in which tubes are unconnected by means of such fittings. For example, the upper ends of single tubes can be arranged in the manner in which the connectors '7, 8, 1'7 and 18 are themselves arranged for the purpose of providing the desired increase in ligament strength.

I claim:

1. In a boiler of the class described, a boiler drum, a plurality of tubes, Y-fittings connecting adjacent pairs of tubes, tubes connecting said fittings with tube holes in said drum, said connecting tubes in a given longitudinal row being connected to tube holes arranged in successive circumferential rows.

2. In a fiuid heater, a drum, a bank of fluid heating tubes arranged in rows extending longitudinally and transversely relative to said drum, means connecting certain adjacent tubes in the same transverse row, connector tubes connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum, certain adjacent connector tubes in the same longitudinal row being connected to tube holes in the same circumferential row, and certain adjacent connector tubes in the same trans verse row being connected to tube holes in the same circumferential row.

3. In a fluid heater, a drum, a bank of fluid heating tubes arranged in rows extending longitudinally and transversely relative to said drum, means separately connecting certain adjacent tubes in the same transverse row, connector tubes connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum, and certain adjacent connector' tubes in the same transverse row being connected to tube holes in the same circumferential row.

4. In a fluid heater, a drum, a bank of substantially vertical fluid heating tubes arranged in rows extending longitudinally and transversely relative to said drum, means separately connecting certain pairs of adjacent tubes in the same transverse row, connector tubes separately connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum, and certain adjacent connector tubes in the same longitudinal row being connected to tube holes in the same circumferential row.

certain adjacent connector tubes in the same' transverse row being connected to tube holes in different circumferential rows.

6. In a fluid heater, a drum, a bank of fluid heating tubes arranged in rows extending longitudinally and transversely relative to said drum,'

means connecting certain adjacent tubes in the same longitudinal row, connector tubes connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum, and certain adjacent connector tubes in' the same longitudinal row being connected to tube holes in the same circumferential row.

'7. In a fluid heater, a drum, a bank of fiuid heating tubes arranged in rows extending longitudinally and transversely relative to said drum,

means connecting certain adjacent tubes in the same longitudinal? row, connector tubes connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum, and certain adjacent connector tubes in the same transverse row being connected to tube holes in different circumferential rows.

8. In a fluid heater, a drum, a bank of fluid heating tubes arranged in rows extending longitudinally and transversely relative to said drum, f

means connecting certain adjacent tubes in the same row, connector tubes connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum a greater distance than the longitudinal spacing of connector 5. In a fluid heater, a drum, a bank of fiuid relative to said drum, means separately connecting certain pairs of adjacent tubes in the same row, and connector tubes separately connecting said means with tube holes arranged in circumferential rows spaced longitudinally of said drum.

ISAAC HARTER.