Stream diameter

Several industrial uses involve the determination of flow rates and liquid volumes. In the flow rate applications, one introduces the tracer into the liquid stream by either pulse or continuous injection and measures the activity as a function of distance. (One must be careful to begin sampling beyond the mixing region, where tracer and fluid mix. This is done by beginning sampling at a distance of 100 x the stream diameter from the point of injection.) When a pulse with activity A Bq is injected into a stream with flow rate F, then F is given simply as... 

Water stream diameter Water velocity in central tubes Water velocity in outer tubes Pressure in central tanks Pressure in outer tanks Pumping power for pile Temperature rise of water in center tube Maximum film drop Maximum metal temperature above that of incoming water, excluding drop at Al-U boundary Maximum carbon temperature... 

Here n is the number of jets, R the velocity ratio (jet over main), d the side-stream diameter, and D the main stream diameter, x is the tailpipe length up to 5D and E is an empirically determined constant depending on B and geometry ... 

Fig. 32). Using a fine pipette insert about i cm. length of the liquid into the bottom of the tube. Now place in the tube A a fine inverted melting-point tube B of about i mm. diameter, sealed at the upper end. Fasten the capillary tube to the ther- Fio. 32. mometer by means of a rubber band and place in a melting-point apparatus. Heat slowly until a stream of bubbles rises from the bottom... 

A simple apparatus for sublimation in a stream of air or of inert gas is shown in Fig. II, 45, 3.. d is a two-necked flask equipped with a narrow inlet tube B with stopcock and a wide tube C 12-15 inm. in diameter. The latter is fitted to a sintered glass crucible and the usual adapter and suction flask E. A well-fitting filter paper is placed on the sintered glass filter plate to collect any sublimate carried by the gas stream. 

Nebulizers can be divided into several main types. The pneumatic forms work on the principle of breaking up a stream of liquid into droplets by mechanical means the liquid stream is forced through a fine nozzle and breaks up into droplets. There may be a concentric stream of gas to aid the formation of small droplets. The liquid stream can be directed from a fine nozzle at a solid target so that, on impact, the narrow diameter stream of liquid is broken into many tiny droplets. There are variants on this approach, described in the chapter devoted to nebulizers (Chapter 19). 

The liquid sample flows into the nozzle and coats the inside walls. The sample stream arrives at the orifice (the nozzle outlet is about 0.01 cm diameter), where it meets the argon stream and is nebulized. 

To accommodate smaller liquid flows of about 10 pl/min, micro-ultrasonic nebulizers have been designed. Although basically similar in operation to standard ultrasonic nebulizers, in these micro varieties, the end of a very-small-diameter capillary, through which is pumped the sample solution, is in contact with the surface of the transducer. This arrangement produces a thin stream of solution that runs down and across the center of the face of the transducer. The stream of sample... 

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