Taking liq. samples e.g. from liq. extn. column - by instrument comprising hollow cylindrical body contg. spring-loaded solenoid-activated needle valve

摘要

A device for taking liq. samples consists of a hollow cylindrical body in which is a needle valve. One end of the body comprises a sampling tip provided with a lip joint in plastic material pref. PTFE. The other end comprises a nozzle for discharging the sample. The needle valve is of smaller dia. than the body so as to leave an annular passage between the valve and the body. One end of the valve is conical and is placed facing the end of the body comprising a sampling tip. The valve can be displaced along the body from a first position in which it is in contact with the sampling tip to a second position in which it is near the other end of the body. The mechanism for displacing the valve consists pref. of a spring and a solenoid winding. The spring bears on the end of the valve away from the conical end and on the inner face of the second end of the body. The solenoid winding surrounds the body and acts on a soft iron core embedded in the valve so as to compress the spring. The valve is guided along the body pref. by three projections on its outer surface at 120 degrees to one another. The device is partic. useful for taking liq. samples from a liquid-liquid extraction column. An acid aq.soln. is used e.g. for re-extracting uranium and plutonium previously fixed by an organic soln. such as tributyl phosphate or trilaurylamine.