Device for ducting gas in a centrifuge block

#This invention relates to a device for ducting gas in a centrifuge block.

#A centrifuge block consists of a plurality of individual centrifuges which, placed side by side and sometimes in several rows, are in communication with each other through tubing. For this purpose, use is normally made of tubes, particularly of metal tubes, connected to the various centrifuges by means of connecting openings. Ducting arrangements of this type require painstaking and extremely careful assembly for safe sealing to prevent the ingress of air into the partially evacuated system.

#In a broad aspect, the present invention provides a device for ducting process gas in a centrifuge block capable of ensuring safe ducting of the process gas while maximally facilitating assembly of the apparatus.

#The accompanying drawings illustrate several embodiments of the present invention, in which

#FIG. 1 is a partial side elevational view illustrating a centrifuge block with covering hood according to a first embodiment of the invention;

#FIG. 2 is a plan view illustrating a centrifuge block fitted with serpentine process gas ducts according to a second embodiment of the invention;

#FIG. 1 illustrates schematically a number of centrifuges of a centrifuge block arranged in respective housings 10. At its upper end, the centrifuge block is held together by means of a plate 11 provided with holes rimmed with annularly cylindrical collars 12 to accomodate the housings 10. At its free end, each collar 12 is welded to the respective housing 10 such that no communication remains between the intermediate spaces above and below the plate 11. At its outer rims, the plate 11 is raised and covered with a flat hood 13, the edges of which are welded or otherwise sealingly joined to the side wall 14.

#When a centrifuge block is placed in operation, the various centrifuges are evacuated, as is the space 15 formed above the plate 11 and enclosed by the hood 13. Arranged within this space 15 are all connections and gas ducts needed for feeding and extracting the process gas. This provides an advantage in that the necessary connections and seals are made within the space enclosed by hood 13 under conditions where there is little difference in pressure and where there are similar gas atmospheres, thereby reducing assembly and sealing problems. More particularly, however, such an arrangement will provide added safety. Full or partial evacuation of the space 15 causes the atmospheric pressure 17 to act on the hood 13, and this pressure can now additionally be utilized to urge the various components together, at least in the sealing areas. This can be turned to advantage for sealing the joint 18 between the hood 13 and the wall portion 14, as well as for urging the process gas ducts 19 against the connecting openings 20 of the centrifuges. Provided also are collector connections 21 to 23 serving to feed and extract the process gas to or from the centrifuge block, respectively.

#The process gas can be ducted in a number of different ways. Use can be made, for example, of process tubes 19 of rectangular cross-section as shown in the embodiment of FIG. 3. Such tubes are disposed in parallel to one another on the respective rows of centrifuges so as to issue into transversely directed collector ducts 25. It is equally practical to use serpentine process tubes 30 as shown in the plan view of a centrifuge block in FIG. 2, thereby eliminating the need for the collector ducts 25 of FIG. 1.