US3406896A

US3406896A - Multiple impeller blower construction

Info

Publication number: US3406896A
Application number: US540737A
Authority: US
Inventors: Chaboseau Jean
Original assignee: Compagnie Electro Mecanique SA
Current assignee: Compagnie Electro Mecanique SA
Priority date: 1965-04-12
Filing date: 1966-04-06
Publication date: 1968-10-22
Anticipated expiration: 1985-10-22
Also published as: FR1440720A; CH436501A; GB1136936A

Description

* J. CHABOSEAU MULTIPLE IMPELLER' BLOWER CONSTRUCTION Oct. 22, 1968 2 Sheets-Sheet 1 Filed April 6. 1966 mu ow mph Oct. 22, 1968 J. CHABOSEAU 3,405,396

MULTIPLE IMPELLER BLOWER CONSTRUCTION Filed April 6, 1966 2 Sheets-Sheet 2 INVENTOR. Jen-n Chaboseau BY M,JJL@&J 8 PM,

8 Claims. a. 230-123 Claims ABSTRACT OF'THE DISCLOSURE A multiple impeller blower structure is located within the tank of a nuclear 'gas reactor for moving the gas With ing the tank. Two or more impellers of functionally separate blower units are located one shaft structure which fl ed S ew P 90 includes a" plurality of axially. spaced bearings therefor which are lubricated by the gas itself Within the tank. The shaft structure is extendedthrough an opening in the tank wall (through which the blowerv structure is inserted and removed) for connection to a driving means therefor such as a motor, and a gland seal is utilized around the shaft extension to prevent escape of gas within the tank. Theblower structure can be supported entirely by the tank wall or in 'part by the tank wall and in part by "a pedestal located within the tank. i

The present inventionrelates to an improvement in blower construction and more particularly to'blowcrs of the type in which the impeller is located within the tank of a nuclear gas reactor for moving the gas. The impeller itself is usually located fairly close to the inner surface of the tank wall, and the entire blower unit is installed from the outside of the tank wall through an opening which is of a sizesufiicient to accommodate and mount the blower housing, as well as the power input shaft for driving the impeller shaft and the piping required for feeding lubricating fluid tothe shaft bearings and seals.

With an increase in size and power of a nuclear gas reactor, more blower capacity is required but this entails much difiiculty in design considerations since the size of the reactor tank wall opening required to accommodate the necessary'increase in blower capacity increases at a faster rate than does the wall space available for-the blower openings, that is to ,say the circumferential length of the reactor tank. i Y

It is not practical to effect any material increase in the capacity of an individual blower through an improvement in design andair'handling capacity since' practically all technically feasible possibilities in 'this direction have already been reached. j 7

The present invention makes it possible to provide a substantial increase'in gas handlingcapacity withinthe reactor tank without, however, necessitating any material increase in the wall opening area required to accommodate the increase.

The objective of the invention is attained by a novel blower structure which provides a plurality of impellers within the reactor tank, each carrying a vaned periphery and the impellers being mounted on a common rotatable shaft fully supported within the tank by longitudinally spaced, gas lubricated journal bearings, the gas used for lubrication being a part of the gaseous fluid within the tank handled by the impellers. A drive shaft for the impeller shaft passes through a wall opening of the reactor tank for connection to suitable prime mover driving means such as a motor, and is sealed at the pass-through point in the wall by means of a stuffing box of conventional construction. The blower structure may be so designed as to be carried entirely by mounting means located at the opening in the tank wall, or suitable pedestal 3,406,896 Patented Oct. 22, 1968 type support structure for the blower may be provided within the tank itself, in which case only theend structures of the blower housing carrying the gland seal through which the drive shaft extends to the exterior of the tank is required to be mounted in the tank wall'opening.

The foregoing as well as other objects and advantages inherent in the invention will become more apparent from the following detailed description of two different embodiments and accompanying drawings which are to be considered as illustrative rather than limitative of the inventive concept as more particularly defined in the ap} pended claims. 7 s 4 I FIG. 1 of the drawings has been include'dto facilitate comparison of the present invention with prior art practiceand shows a conventional single impeller blower construction in central longitudinal section. u

FIG. 2 is a view in'central longitudinal section of one embodiment of a multi-impeller blower construction in accordance with the present invention, the blower being provided with dual impellers and being supported within the reactor tank entirely by mounting means located at the tank wall opening through which the drive shaft extends.

FIG. 3 is a view in central longitudinal section similar to FIG. 2 but showing a slight modification wherein most of the weight of the blower is carried by a pedestal type of support located within the reactor tank.

With reference now to the drawings and to FIG. 1 in particular, a typical blower construction of conventional design is seen to comprise a radially vane-d impeller 1 mounted on one end of a shaft 2 which is supported for rotation on its axis 11 by means of two longitudinally spaced

bearings

3, 4 of the journal type which are lubricated by oil. An extension 6 of shaft 2 leads to a coupling, not shown, by which the shaft can be connected to" a prime mover such as a motor for rotating the impeller. The housing structure 7 for the blower carries the

bearings

3 and 4 and also a gland seal 5 surrounding shaft '2 and located between the impeller 1 and bearing 3. This seal 5 serves to isolate the gaseous interior 9 of the reactor tank from the exterior thereof where atmospheric conditions exist. The tank wall is indicated at 9 and is assumed to be generally cylindrical and disposed vertically, the vertical axis of the tank being indicated by-the dash-dot line 10. The blower housing structure 7 is circular and is secured around its periphery to a corresponding circular flange part 8 defining an opening 12 along axis 11 provided in a fiat along the tank wall 9.

One embodiment of the improved blower construction in accordance with the present invention is illustrated in FIG. 2. Here it will be seen that substantially the entire blower structure is located within the reactor tank adjacent a side wall 9. A plurality of gas impellers, such as the two

impellers

13 and 14 are mounted symmetrically inlongitudinal spaced relation on a hollow shaft 15 and the latter is supported for rotation on its axis by two longitudinally spaced

bearings

16 and 17 of the gas lubricated type. The gas utilized for lubricating these bearings is the gas contained within reactor tank and which is to be set in motion by the dual impellers. The motive power for rotating shaft 15 is obtained by a drive shaft 18 which extends from a point exteriorly of the tank wall 9 through an opening 12 and gland seal 19 carried by circular end wall 20a of the blower housing 20. The inner end'of drive shaft 18 which extends within the hollow shaft 15 to approximately the middle thereof is enlarged radially at 18' and secured to the inner wall of the hollow shaft. Blower housing 20 is secured in place within the wall opening 12 by a connection between the periphery of its end wall 20a and a circular flange part 8 which defines the tank wall opening r fi}58,406,896...

1 I P1 r ..1-t. s ia ed w a t a y pa t 20b of the blower housing for guiding the flow of gas handled by this impeller, and a similar stationary part 200 is associated with the other impeller 14.

It will be evident'from FIG. 2 that the blower, including its support shaft 15 and its gas lubricated

bearings

16, 17 are entirely immersed in the gaseous atmosphere prevailing within the reactor tank, and that the gas-atmosphere seal 19 is made around the drive shaft 18. As an alternative, the seal 19 may be made around a sleeve associated with the drive shaft. 7 i

A slightly modified construction of the improved blower in accordance with the invention is illustrated in FIG. 3. This embodiment is essentially the same as that of FIG. 2 and hence, all like parts have been given the same reference numerals. The only difference between the two lies in the manner in which the blower is mounted within the reactor, tank. In the embodiment of FIG. 2, the entire weight of the blower is carried by the end wall 20a at its peripheral connection to the flange part 8 which defines the opening in the tank wall. In the embodiment of FIG. 3, it will be seen that substantially the entire mass of the blower is supported within the reactor tank by means of a pedestal part 21 of the tank. With this type of construction the only part of the blower carried at the tank wall opening is the end wall 20a, seal 19 and drive shaft 18.

While two different embodiments of the invention have been described and illustrated, other various changes in the construction and arrangement of parts may be made without, however, departing from the spirit and scope of the invention as hereinafter defined. Thus, for example, while a. dual-impeller construction has been illustrated for effecting an increase in the total gas handling capacity of the blower within the reactor tank without requiring any increase in tank wall opening over that required for a prior art construction as depicted in FIG. 1, more than two impellers may be mounted on the gas-lubricated bearing supported shaft within the reactor tank and the impellers may be single stage design, as depicted or multi-stage. Moreover, both of the gas-lubricated

bearings

16, 17 for shaft 15 can be located to the outside of the

impellers

13, 14 rather than between them as depicted, or one of these bearings can be located between the impellers while the other is located to the outside.

I claim:

1. Blower apparatus for and located within a sealed enclosure such as a nuclear gas reactortank in which gas is to be moved, and isolated from atmospheric conditions which exist outside of said enclosure, said blower apparatus comprising a blower housing, means supporting said blower housing within said enclosure, a shaft within said blower housing, bearing means of the gas-lubricated type supporting said shaft for rotation about its axis, the gas used for bearing lubrication being the gas which is to be moved by said blower apparatus and in which the latter is immersed, a plurality of impellers located in spaced relation along said shaft each of which serves to move a separate portion of the gas within said enclosure, a sepa- .rategas inlet and gas outletcorrelated. to eachimpeller, a

, pellers.

3. Blower apparatus as defined in claim 1 wherein said gas-lubricated bearing means for'said shaft on which said impellers are mounted are constitutedby a pair of longitudinally spaced bearing units located to the outside of said impellers., I I 4. Blower apparatus as defined in claim 1 wherein said shaft which mounts said impellers in hollow and said drive shaft therefor extends within said hollow shaft, said drive shaft being of smaller diameter than the internal diameter of said hollow shaft and including 'a single radial enlargement thereon by which connection is made to the inner surface of said hollow shaft.

5. Blowerapparatus as defined in claim 1 wherein said means supporting said, blower. housing within saidenclosure are constituted at least in part by a connection between an end wall of the housing and the surrounding periphery of the wall opening through which said drive shaft extends.

6. Blower apparatus as defined in claim 5 wherein said means supporting said blower housing within said enclosure including a pedestal type. of support which carries a major part of the mass represented by the blower as a whole. 1 p

7. Blower apparatus as defined inclaim 5 wherein the entire mass represented by said blower as a whole is carried by said connection between the end wall of the housing and the surrounding periphery of the wall opening in said enclosure.

8. Blower apparatus as defined in claim 5 and wherein said sealing means surrounding said drive shaft is located in said end wall of said blower housing. I

References Cited HENRY F