A MAGNETICALLY-ACTUATED GLASS PUMP FOR CIRCULATING GASES R. J. BRUNFELDT and V. C. F. HOLM Phillips Petroleum Company, Bartlesville, Oklahoma either of metal1 or g1ass"ave been described in the literature. From the standpoint of freedom from contamination, leakage, or corrosion problems, an all-glass pump that can be sealed directly into the apparatus is usually the most desirable. The glass pump described here was designed and built in our laboratorv. " , and has given excellent service in an apparatus for investigating the reducibility of metal oxides with hydrogen. The construction of the pump is indicated by Figure 1. The cylinder and piston, A, were adapted from a Pyrex, 5-ml. hypodermic syringe. A bundle of soft iron wire was sealed within the glass piston which is moved back and forth inside the cylinder by alternately energizing the two solenoids C, and C;. The arrangement of the four spherically-ground check valves B makes ~urnuine . - action effective with each movement of the piston. The inlet and outlet lines are of 6-mm. outside diameter Pyrex tubing, and the over-all dimensions are about 4l/, X 4l/* in. The pump is operated with the cylinder in a horizontal position, whereas the valve compartments are vertical. The coils Cl and C2are '3/16 X 2 in., and are wound with approximately 3000 turns of 30-gage, enameled copper
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A, &lass pistoo with sealed-in iron aore: B, ball ohack va1ae; C, and
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A power supply was constructed to provide direct current for alternatelv enereizine the two solenoids. PRECISE laboratory investigations where gaseous The power supply employs a&pe-6x4 rectifying tube, reactants are recirculated through reaction zones or and delivers approximately 65 milliamperes a t 200 absorbents, i t is important that adequate circulation be volts d. o. in normal operation. The detiils are shown maintained without leakage or contamination. Some- in Figure 2. The power is applied,alternately to each times an apparatus can be designed so that circulation coil by means of a single-pole, doublethrow microcan be developed by suitable heating of an exposed sec- switch operated by a cam rotating a t 60 r. p. m. tion to produce a thermal syphon effect. However, The pump will operate against a back pressure of this arrangement is not always effective, particularly if about 20 millimeters of mercury and delivers from 150 some component of the circulating system offers ap- to 200 milliliters of air at normal temperature and prespreciable resistance to gas flow. Several types of sure. During continuous use it may be desirable to magnetically-operated circulating pump constructed provide an air jet for cooling the coils and pump cylinder, but this is not neressary for intermittent operation. alternately energiae.3 solenoids.
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ACKNOWLEDGMENT The authors acknowledge the assistance of W. C. Hahn, who was responsible for the design and construrtion of the power supply and the solenoids. Acknowledgment is also made to the Phillips Petroleum Company for permission to publish this article.
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ROSEN,Rev. Sn'. Imnslr., 24, 1061 (1953). 'PORTER,BARDWELL,AND LIND,Ind. Eng. Chem., 18, 1086 (1926); FUNNELC AND HOOVER, J . Phw Chem.,31, 1099 (1927); LMNGSTON,ibid., 33, 955 (1929); WILSON,OTVOB,STEVENSON, AND WAGNER, Ind. Eng. Cha.,45, 1480 (1953). 528
