Agitator and Drive Unit Fills Need For Bench-Scale Testing Equipment A versatile agitator and general-purpose drive is the newest unit in Bench Scale Equipment Co/s line of laboratory equipment for product and process research. The new Benco Model R is based on an earlier West German unit. The Dayton, Ohio, company modified the German design and added some accessories which significantly extend the flexibility and usefulness of the drive. The drive comes in two models, providing a choice of size and power outputs with a selection of continuously variable speeds from 17 to 2925 r.p.m. The larger model (4-R) uses a Vé-hp. motor; the smaller (2-R) uses a Vio-hp. motor. The main support column allows 17V 2 in. of vertical travel for both models, which also have adjustable shaft length and variable shaft angle through 360°, Benco says. Three interchangeable gearheads are available for each model, as are 14 standard option impellers (small-scale versions of commercial types). There is also a universal power take-off connection for special laboratory applications.
The Model R can be used for laboratory or prepilot-plant testing which involves blending, solids suspension, reaction kinetics, gas-liquid contacting, emulsification, dispersion, and homogenization, Benco says. It can also be used as a drive for small-scale conveyors, vibrators, grinders, liquid and vacuum pumps, milling, tumbling, rotary and wiped-film evaporators and any equipment requiring a variable-speed, varable-position drive source. Specialty Line. Bench Scale Equipment Co. (acquired last year by Chemineer, Inc.) now has about 15 pieces of equipment in its specialty line. Included are several types of experimental agitator units, the Kinetics Kit (used to study reaction variables and scale-up criteria for batch and flow-reactor systems, for instance), and bench-scale rotary and pneumatic dryers. Robert L. Bates, president of Benco, says that demand is growing for bench-scale equipment. It might seem at first glance, Mr. Bates says, that the trend in chemical engineering education away from equipment-ori-
DRIVE. The Benco Model R laboratory drive, being used here as an agitator at Laboratory of Protective Treatments, Inc., was developed at Bench Scale Equipment Co. for laboratory or prepilot-plant tests that involve blending, solids suspension, reaction kinetics, gasliquid contacting, emulsification, dispersion, and homogenization
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ented subject matter toward a unified fundamental approach might mean the end of both bench-scale and pilotplant equipment in academic and industrial work. But the situation is just the opposite. Bench-scale equipment, he notes, will become increasingly important because of the need to demonstrate concepts. The need to demonstrate the validity of an idea and the desire for data are still present. But there is "an increasing unwillingness" to spend as much time as has been taken in the past with large equipment. Bench-scale equipment also has considerable potential in developing mathematical models for computer design programs. Many of the parts of an equation need to be established experimentally. And the range of values necessary to do this demands equipment in which the parameters can be conveniently (and economically) varied. The increasing tendency of many engineers in the chemical industry to bypass the pilot plant also puts greater emphasis on the need for bench-scale equipment. But the parameters of such an experiment must be well defined. "Better data at the bench make for better input data for the computer," Mr. Bates notes. Scale-up is thus more accurate. Problems. Many of the problems in bench-scale work, such as plugging and problems of heat transfer and flow control, derive mainly from using setups extrapolated from the glassware stage. These problems tend to disappear, Mr. Bates believes, in competently designed bench-scale equipment, scaled down from commercial styles. It isn't always easy to get smallscale equipment. Often companies find it necessary to buy the smallest available size of plant-scale equipment. Generally, such equipment is not designed for experimental work and permits little variation in operation. In many cases, companies must design and build their own equipment, at considerable expense and inconvenience. Mr. Bates sees Benco filling a specific need in chemical engineering the considerable gap between the laboratory supply house and the specialized manufacturer of commercial equipment. No company, he says, has made an effort to provide a single integrated source of equipment in that area.
CARLISLE ADDS 2 PHOSPHINES Tri-n-octylphosphine and triphenylphosphine have joined tri-n-butylphosphine in Carlisle's line of phosphines. Like TBP, they are more reactive than the structurally analogous tertiary amines. Activities of TOP and TPP are successively less than that of TBP due to the increasing complexity of their organic radicals. Like TBP, both are reducing agents and both form quaternary phosphonium salts. TOP is basic and reacts with acids; TPP is neutral. All form pentavalent compounds, such as the oxide, sulfide, dihalides, imines and -ylenes. Triphenylphosphine can undergo the Wittig reaction for converting carbonyls to olefins.
PHOSPHINE
COMPARISON
TABLE
Tri-n-butylphosphine
Tri-n-octylphosphine
Triphenylphosphine
Liquid: b.p. 150°C [50 mm) Most reactive Mildly basic Oxidizes in air Forms water soluble phosphonium salts Purity 95% min.
Liquid: b.p. 295°C [50 mmj Less reactive Mildly basic Less easily oxidized Forms water insoluble phosphonium salts Purity 95% min.
Solid: m.p. 80°C
TYPICAL
PHOSPHINE
Least reactive Neutral Does not oxidize in air Phosphonium salts show mixed solubility Purity 99% min.
REACTIONS
Write for data sheets and trial samples. Other phosphines and phosphine derivatives are in research—watch for their release.
CARLISLE CHEMICAL WORKS, INC. D E P A R T M E N T C-1 02, RE A D I N G, O H I O S P E C I A L
C H E M I C A L S
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Soap and Detergent Association Sets Up Biodegradability Determination Test A procedure for determining alkylbenzenesulfonate (ABS) and linear alkylate sulfonate (LAS) biodegradability has been established by the Soap and Detergent Association. The procedure was officially released at the 39th fall meeting of the American Oil Chemists' Society, in Cincinnati, Ohio. Details are scheduled for publication in the November issue of the Journal of the American Oil Chemists' Society. The S&DA procedure consists of two microbiological tests—a presumptive test involving the shake flask method, and a confirming, semicontinuous activated sludge test. In both tests, samples are regularly withdrawn and analyzed so the course of surfactant biodégradation can be followed. The surfactant must be 90% degraded to be considered biodegradable, S&DA research director Theodore E. Brenner told the meeting. The association set up a subcommittee on biodégradation test methods in 1961 to develop and evaluate test procedures. The program was a cooperative effort involving about 20 detergent raw material suppliers and product formula tors. Many approaches were considered, but the shake flask and the semicontinuous activated sludge seemed to be the most promising. Tests. The simple shake flask method is used as the screening or presumptive test. The confirming test is the semicontinuous activated sludge procedure. The screening test takes eight days. A basal medium is prepared and placed in Erlenmeyer flasks. Next, the surfactant is added to the flasks and the resulting growth medium is inoculated with microorganisms. The flasks containing the basal medium, surfactant, and inoculum are placed in a shaking machine for aeration. To follow the biodégradation, samples are taken immediately after inoculation and mixing of the flask and again on the seventh and eighth days. Net surfactant concentration is calculated by subtracting the analyzed value for a blank sample from the analyzed value for samples in the flasks. Per cent removal is calculated from reduction in surfactant concentration. The result of the test is the average of seventh and eighth day per cent removals. 46
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If surfactant reduction equals or exceeds 90%, the surfactant is considered to be adequately biodegradable and no further testing is needed, Mr. Brenner points out. If reduction is below 80%, the surfactant isn't biodegradable enough. Confirming. If reduction is between 80 and 90%?, the confirming test must be applied. Activated sludge, surfactant, and a synthetic sewage are placed in a specially designed aeration chamber. The sludge, which contains microorganisms, is from a sewage treatment plant. The synthetic sewage is used as an energy source for the sludge microorganisms. The mixture is aerated for 23 hr. and allowed to settle for 30 min. The supernatant liquid is removed and sludge remaining in the aeration chamber is brought back to volume with fresh surfactant and synthetic sewage. Then the cycle is repeated. According to Mr. Brenner, the minimum time needed for testing a surfactant is 15 days. The per cent surfactant removed is calculated daily, starring with the fourth day. The result of the test is the average per cent removed over seven days, during which: • Difference in removal on any two consecutive days is not more than 5%. • Difference in average removal for the first three days and average for the last three days is no more than 3%. Under the confirming test, if surfactant reduction is at least 90%, the surfactant is considered to be adequately biodegradable.
Coil Spring Drives Vibratory Pan Feeder A motor-driven, vibratory pan feeder uses a new concept that enables the feeder to combine conventional shortstroke, high-frequency action with long-stroke, low-frequency action for moving-difficult materials. Developed by Carrier Mfg., of Jefferson, Ind., the new concept makes it possible to reduce feeding rate essentially to zero while reducing motor speed only 2 5 % . This reduction is possible because the drive of the motor is applied to the
vibrating pan through a coil spring that has a natural frequency near the motor's synchronous speed. Thus, at vibrating frequencies near this speed, the Adjust-A-Flow feeder has maximum stroke. As the speed of the motor is reduced, the motor becomes out of phase with the frequency of the driving spring. This presents a greater spring resistance to the motor and the stroke is diminished. Thus, a small change in motor speed causes a substantial change in feeding rate.
Sensitization Raises Laser Efficiency Both Westinghouse and Radio Corp. of America have significantly increased laser efficiency by basically the same method—"sensitization." Westinghouse scientists Ν. Τ. Melamed, Chikira Hirayama, and Ε. Κ. Davis used a neodymium-glass laser, and RCA scientists Robert J. Pressley and Peter V. Goedertier used a neodymium-garnet laser. A laser emits light because a host material composing the laser rod con tains a small amount of impurity, as ions. These ions are pumped from their normal to a higher energy state by light from a flash tube. A fraction of a second later, as these high-energy ions return to their low-energy state, they emit light. Sensitization is a method of forcing more primary impurity ions to absorb pumping energy by -adding a second impurity to the host material. The Westinghouse group adds manganese; the RCA group adds chromium. According to the Westinghouse group, manganese ions in its laser do not fluoresce. Instead, they act as energy transfer agents. Light from a flash tube pumps them to a high level along with neodymium ions. But be fore the laser pulse occurs, manganese ions transfer their energy to neody mium ions. The result is a larger number of excited neodymium ions, which produces a larger pulse. The RCA group says that some chromium ions in its laser do fluoresce, but the majority transfer their energy to neo dymium ions. Each group says that it has at least doubled the efficiency of its laser. This combination of power and effi ciency could make such lasers attrac tive for micromachining and for drill ing and working refractory materials.
Aluminum Ceramic Lamp Reduces Lighting Costs The commercial availability next January of General Electric's Lucalox lamp may usher in the third age of lighting. At its Nela Park headquarters in Cleveland, the company's lamp division disclosed last week that it is ready to begin marketing a new line of commercial and industrial lamps developed by GE's Dr. Kurt Schmidt and William C. Louden. Belonging to the family of highintensity electric discharge lamps (which include mercury and multivapor types), the new lamp is the most efficient source of white light of acceptable color quality in the history of electric lamps, GE says. For instance, a 400-watt lamp (the first of the Lucalox line to go on sale) produces about 42,000 lumens. This output is equivalent to about 50 household bulbs of 60 watts each, 13 fluorescent lamps of 40 watts each, or two 40-watt mercury lamps. A second Lucalox lamp (available early in 1966) produces about 25,000 lumens. Later on, GE plans to sell four additional Lucalox lamps with outputs from 8000 to 100,000 lumens. The lamp's intense white light is produced inside a cigarette-size Lucalox arc tube. The high-density, polycrystalline aluminum oxide tube allows using alkali metal vapors at much higher pressures and temperatures than have been practical before. Sodium pressure in the arc of the 400watt lamp, for instance, is about 200 torr—about 100,000 times higher than pressures used in older sodium light sources. The electrical characteristics of the new lamps require specially designed ballasts. The lamps will thus be used in new or remodeled lighting installations. Uses. Typical uses include lighting for large indoor and outdoor areas. GE expects that the new lamps will be used later in commercial and institutional interiors. Lucalox lamps will increase street and highway lighting levels by about 50% above mercury installations at the same operating costs. Compared to GE's 8-ft. Power-Groove fluorescents, the 400-watt Lucalox lamps will provide industrial users with about 60% more light for the same initial cost. The lamp (ordering designation LU-400) will have a list price of $45.
RETIRED !
E0DAIF1 because he lost the scent The keenest nose finds no trace of unpleasant odor in your product or process when you use Deodall # 1 . . . Sindar's multi-purpose masking agent. From consumer paints and home heating oils to industrial textile finishes, or polishes, or solvents, Deodall #1 has found successful application. In fact, wherever offensive odor is cause for complaints or lack of sales, you may well find a use for Deodall # 1 . Deodall #1 is simple to use, and exceedingly varied in its application potential. If you have an odor problem, you should consider Deodall # 1 . Certainly contact Sindar for samples and technical information.
illlDflf 321 West 44th Street, New York 36, New York
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