GB1265139A - - Google Patents

Abstract

1,265,139. Supplying fluid samples. TECHNICON INSTRUMENTS CORP. 16 June, 1970 [20 June, 1969], No. 29137/70. Heading B8N. A flow control system for supplying fluid samples, e.g. of corrosive liquids, comprises sample storage means 32, 39, means 62 for pumping samples into the storage means 32, 39, means 68, 70 for pumping the samples out of the storage means 32, 39 at a substantially constant flow rate, and means 30 for transferring the storage means 32, 39 between operative connection with either pumping means, there being additionally means to introduce a bubble of air to the sample storage means during transfer. In an initial position, Fig. 2, the pump means 62, e.g. a vacuum pump, draws fluid from a sample cup 14a through a take-off tube 20 and conduit 12, coils 34, 36 of one storage means unit 32 being connected to the conduit 12 and a pump flow resistance coil 60 by bores (76), 80, (88), Fig. 3 (not shown), of a fixed lower valve plate 26. When the coils 34, 36 have been filled, an upper valve plate 28 supporting them is rotated through 90 degrees by the operating means 30, bores 78, 82-86 aligning with ports 108-114. Compressed air from a line 64 partially expels the sample through a conduit 66, leaving air bubbles in the coils 34, 36, and on rotating the plate through a further 90 degrees, Fig. 4 (not shown), cf. Fig. 2, the bores 78, 82-86 align with lower valve plate passages (92), (96), (102), (106), Fig. 3 (not shown). Silicone oil pilot fluid is then pumped through inlet conduits 68, 70, the sample fluid in the coils 34, 36, separated from the oil by the air bubbles, being ejected through lines 72, 74 to analysing means (not shown). On rotating the plate 28 to its initial position, the take-off tube 20 is connected to a washing liquid reservoir 22, operation of the pump 62 flushing out the storage means 32. Two sets of storage means 32, 39 are provided for concurrent operation, a sample supply device providing a series of samples in turn.