Radio age research, manufacturing, communications, broadcasting, television (1941)

and eliminates the necessity of usinjj- much more elaborate equip- ment." Individual credit for the develop- ment of the high-frequency dehy- drator has been given to Dr. George H. Brown, 35-year-old research en- gineer, of RCA Laboratories, who was inspired in making his inven- tion by a newspaper story he read on the production jiroblems of peni- cillin, the demand for which, over- seas and at home, has far exceeded the supply. He received helpful as- sistance from his associates, R. A. Bierwirth and Cyril N. Hoyler, and from scientists at the Squibb Bio- logical Laboratories, the latter pro- viding most of the ])enicillin solu- tion for his experimental runs. Dr. Brown's radio-frequency sys- tem deals directly with the prob- lem of the bulk-reduction of puri- fied penicillin, rather than with the production of penicillin itself. After the penicillin is produced by tlie mold either by surface or submerged fermentation in con- tainers holding up to several thou- sand gallons, the penicillin-contain- ing broth is separated from the mold by fdtration and the crude penicillin extracted from the broth with an organic solvent. It is then given an elaborate series of chem- ical treatments which finally re- move most of the impurities and reduce the bulk by about 600 times. This is the i)oint where the final bulk-reducti(in must begin for, while the penicillin in solution now has a potency of about 40,000 units per cubic centimeter, the objective is to attain 100,000 units per cc. Once that is accomplished, the penicillin is freeze-dried to powder form in ampuls for shipment to places of urgency designated by the War Production Board. Since ordinary heat methods of evaporation destroy the effective- ness of penicillin, the bulk-reduc- tion in plants under WPB control has been achieved through freeze- drying, a process in which the penicillin solution is caused tn evaporate in a high vacuum at below-freezing temperatures. Dr. Brown's electronic bulk-re- ducer employs radio - freipiency current to concentrate the i)enicil- lin solution. His system consists of three large glass bulbs, con- [8 RADIO AGE] nected in vertical series, and at- tached to a pump that maintains a relatively low vacuum. To the setup is connected a 2,000- watt radio - frecjuency generator. Electrodes carrying the outinit of the electronic generator are at- tached to the base of the lowest glass bulb which, when the unit is in operation, holds about 200 cubic centimeters of liquid. As the vacuum pump starts, the suction draws the solution into the base of the lower bulb. The radio current is turned on and, as the current passes through the solu- tion, heat up to .50 degrees is cre- ated and the liquid boils. This causes an evaporation at the I'ate of two litres an hour. Laboratory Model Installed It was Dr. Brown's laboratory model, built in its entirety at RCA Laboratories, that was installed at the Squibb penicillin production plant on May 5. There its oi)era- tion was observed l)oth by Mr. Holaday and by Mr. C. \V. Eber- lein, superintendent of the plant, who after conducting exhaustive tests, announced they are ready to place it ill steady production. The apparatus occupies a floor space roughly .'5 x 5 feet and is ap- proximately 7*'2 feet tall. Electronic bulk-reducing equip- ment, based upon the model, will be manufactured and marketed by the RCA \'ictor Division, Camden, N. J. In an interview. Dr. Brown re- called some of the problems with which he contended as he sought to I)erfect his invention. One of the ditficulties that had to be overcome in the original setup of two con- nected glass cylinders was exces- sive foaming, which slowed up the process. The thought occurred to him that glass marbles placed in tlie connecting necks of the cylin- ders might be effective. The scientist sent out a messen- ger, who visited all of the shops in the town of Princeton without so much as finding a marble. Dr. Brown called his home and enlisted his wife to search his children's Ix'longiiigs. Still no marbles. Fi- nally, his wife reported that one (if the neighbor's children, John Turney, who "played for keeps", had a shoe-box containing 1,000 glassies. This sujiply was tai)ped and science moved ahead. Dr. Brown's final solution, how- (■\( r, was to replace the two glass cylinders and marbles with the three glass bulbs of his model, and add a water coil. Further, the peni- cillin w.is "degassed" before plac- ing it in the containers. Dr. Brown ('xi)Iaini'd that boiling occurs in the bottom bulb, the next bulb takes care of excessive foaming, and the Ihird is "just for good measure." CYRIL N. HOVLKK (LEFT). DR. OEORGE H. BROWN, AND R. A. BIERWIRTH SHOWN WITH THE ELECTRONIC DEHYDRATCR.