Fig. 29.—Stationary Turbo-Exhauster with Dust Separator.
Fig. 30.—Portable Turbo-Exhauster Driven by 1½ h.p. d.c. Motor.
It is not generally recognized what enormous amounts of dust and dirt may be extracted by these machines. From one London hotel a ½ h.p. cleaner removed 166 lbs. of dust from the carpets of the public rooms only. On a cleaning test in a first class dining car on one of the English railways 25 lbs. of dust was removed from 38 sq. yds. of carpet. A rug in front of a lift in a London stores yielded 91 lbs. 1 oz. of dirt to a small machine.
The stationary plants are usually installed in the basements of large office buildings, theatres, hotels, clubs, etc., and the whole building is piped suitably, wall plugs or connectors being fitted to which the staff make connection by flexible hose as and when required. The free end of the flexible hose is fitted with one or other of a series of special nozzles, the latter being adapted to the varying requirements of everything in the room from floor to ceiling.
With the portable hand sets or even with the larger truck type, the design is complete as a working unit; the equipment is used as manufactured and there is little or no chance for the user to endanger the working efficiency of the plant. In permanent plants, however, as installed in hotels, etc., it is necessary that all points previously mentioned regarding pipe lines, valves, junctions, bends, etc., should be considered and acted upon.
The pipe lines should be too large rather than restricted in any way, the suction flexible should be kept as short as possible, and if necessary extra connections should be allowed rather than require flexibles too long for use without “kinking.”
Fig. 31.—Suction Cleaning for Railway Carriage Cushions.