TECHNOLOGY
Volume Ratio Basis of Blending System Packaged electronic control system adjusts total volume, not flow rate, blends streams continuously Fischer & Porter has taken the wraps off a new packaged electronic control system for continuous in-line blending of two or more fluids. The system, which relies on total volume ratio rather than on flow rate ratio, is now on display at F&Ps Colburn Memorial Flow Laboratory in Warminster, Pa. In the new system, F&P keeps feed streams in proper proportion by continuously checking the total volume fed into the blend by the feed streams. F&P standard turbine flow meters placed in each feed stream send impulses to electronic equipment which continuously monitors instantaneous total quantity ratio, "remembers" the total amount of each component put into the blend by each stream, and adjusts feed rate to bring total volume ratio back to a set-point should it stray. Advantage of the total volume scheme, F&P engineers explain, is that the final blend ratio desired is always obtained. In a system based on flow rates, although an error in flow rate may be corrected, the volume error incurred while the correction is being made is left in the system. The electronic equipment has little effect on the accuracy of the system; controlling factor is the accuracy of the turbine flow meters. And, since total volume is being metered, any small control loop error quickly becomes insignificant as the blend run progresses. Accuracy runs about ± 0 . 5 # of each stream reading and repeatability of any given blend is ±0.2c/c or better. Starting with a basic two-feed stream system, F&P can adapt its technique to systems with 20 or more feed lines. More sophisticated electronic equipment can be added, such as a sealer-totalizer which converts pulse readings from an arbitrary scale to direct reading in engineering units such as gallons or barrels. Cost varies from about $5500 to $10,000 per feed line, depending upon extras. How It Works. In the system which F&P put on display (and which will soon be dismantled and shipped to the 50
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first customer), a main stream and a component stream are equipped with turbine meters which develop electrical pulses proportional to fluid volume passing through them. The pulses go to a transistorized digital comparator, which detects cumulative count differences between the pulses, displays them, with plus or minus signs, on flashing (nixie) tubes. The digital comparator also puts out an analog voltage, proportional to this count difference, which it transmits to an electronic controller. This instrument compares the voltage with a fixed set-point, compensates for any difference by sending 1 to 5 milliamp. d.c. control signals which actuate a diaphragm motor valve placed in the component stream. One extra in the display system is a ratio setter through which pulses from the component-stream turbine meter pass en route to the digital comparator. Purpose of this gadget is to provide a means of changing the desired feed stream ratios without having to switch turbine meters. F&P sees a big potential market for its system in gasoline blending. But its uses can run the gamut—from cutting ethyl alcohol with water to in-line blending of two different beers.
Burroughs Offers New Data Processing System A new data processing system—the B5000—has been developed by Burroughs. The company says the new computer combines high internal speed (3 microsec. per addition) with simplified man-machine communications. The unit features automatic programing, accepts both ALGOL (algebraic language) and COBOL (common business language). In addition, Burroughs claims these advantages for the B5000: It requires minimum operator intervention; it can be added to or changed without reprograming; and it can handle two or more completely independent programs simultaneously.
Constructed of modules, the B5000 can be upgraded to take advantage of new developments such as thin film devices, Burroughs says. The new computer uses small transistorized packages as its standard plug-in units. (There are about 10,000 of these units in a medium sized B500 system.) Burroughs claims these units cut spares needed on site by 60%, reduce overall size, and are easy to replace. Rent for the new computer will be from $13,500 to $50,000 a month, depending on the size of the system. Sale prices will range from $540,000 to $2 million. First deliveries will be in 18 months.
RCA Markets Line of Nuclear Gaging Instruments Radio Corporation of America has moved into the nuclear gaging field with a full line of gamma ray measuring devices. The devices include a gamma ray source, a detector, and electronic presentation chart, digital, or other form. Typical uses for the equipment include measuring thickness and density, detecting and controlling voids and seams, and measuring and controlling liquid level. RCA, undoubtedly impressed by last year's soaring sales of nucleonic instruments, will be facing stiff competition from several smaller companies that already have a considerable head start (C&EN, July 25, 1960, page 5 0 ) . These companies include Industrial Nucleonics; Ohmart Corp.; Instruments, Inc.; Curtiss-Wright; and Nuclear-Chicago.
Eastman Kodak to Enter Magnetic Tape Field Eastman Kodak will manufacture and sell magnetic recording tape, beginning later this year. Initially, the company will market a triacetate-based tape, packaged in rolls V 4 -in. wide in standard lengths, for professional and amateur sound recording uses. Later it may also supply tapes for other uses such as instrument and electronic computing. Kodak's move into magnetic tape is not unexpected. Kodak Pathe, the firm's French associate, has been producing and selling tape abroad for over 12 years, receiving considerable technical aid from the Rochester laboratories. And Kodak has for some time supplied Kodapak plastic sheeting to other tape manufacturers.
