NEW PRODUCTS Instruments
INSTRUMENT SWITCHES BETWEEN MANUAL AND AUTOMATIC PROCESS CONTROL MODES A new line of process control instruments will soon be made available for bumpless switching between manual and automatic control modes. Use of new instrument is claimed to obviate often complex procedures, and possibility for error, which is quite high for rapid switchover, particularly under emergency conditions. Newly developed pneumatic analog device, called Syncra, continuously matches controller signals to balance pressures, and align control points. Both the 2-in. x 6-in. Mini-Syncro and the 6-in. x 6-in. Syncro units are designed for optimal operation. T h e operator always drives a process upscale by pressing the right-hand pushbutton on each station face: the process is driven downscale by pressing the station’s left-hand button. O n manual and on automatic, all Syncro stations are operated in an identical manner, whether the valve is air-to-open or air-to-close, and regardless a€ whether the controller is direct- or reverse-acting. A rocker bar, with an optional built-in alarm light, is used to actuate the pushbuttons on the 2-in. x 6-in. Mini-Syncro. Computer-Control Application. T h e new Syncro line may serve as a link between operator and computer control. Syncro stations would also provide built-in safety for backing u p computer control in power plants, and in other installations where bumpless transfer is required in emergency situations. Syncro stations are designed so that a single master switch or panic button, activated by operator or by computer, can take an entire plant or process, with hundreds of control loops, from automatic to manual control instantly and without bumping the process.
No mechanical switches or clutches are employed in the new Syncro stations. Instead, a pair of pneumatic Syncros, used with each station, ensure continuous balance between automatic and manual con. trol. One Syncro is used to provide a control-point signal: the other Syncro operates the valve when the switch is in the manual position. I n the automatic control mode, the valve-loading Syncro continuously aligns itself to the controller output. Conversely, in the manual mode, the valve-loading Syncro is controlled by the same pushbuttons on the station face, and the con trol-point Syncro continuously aligns itself to the process signal as it changes with valve loading. Con-
trol-point and process-variable sicnals are hence always equal, and the controller output is always equal to the manual loading pressure for instant return to automatic. Bumpless transfer from manual to automatic requires that the reset pressure be exactly equal to the manual loading pressure. I n presently available equipment, however, the only communication between the manual valve-loading pressure and the reset-chamber pressure is through the reset needle valve. T h e restriction imposed by the needle valve introduces a lag in arrival at equilibrium between pressures. Thus, a “bump” results when (Continued on page 94)
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From Da Pont resear&. the &&&estpzcaZi2-y
Methacrylate Monomers avaiZabde today To further help you produce top quality end-products, D u Pont has improved the specifications of all their methacrylate monomers. T h e new specifications are the finest available in tKe industry. These new, improved specifications reflect the years of production experience that insure the consistent high purity of D u Pont methacrylate monomers. As a user of these quality D u Pont methacrylate monomers, you can call on Du Pont’s experience in acrylics to help you produce better products. And you can rely on D u Pont for technical service, handling technology, engineering assistance, and fast, dependable delivery.
A free subscription f o r you “Methacrylate Briefs” is a new bi-monthly D u Pont publication that abstracts patents and literature references pertaining to methacrylate monomers. Write us if you’d like to receive copies or contact your D u Pont Electrochemicals Department representative. H e can also answer your questions about our methacrylates, explain the savings you can get on mixed shipments of monomers, and discuss requirements you may have for monomers D u Pont does not now supply.
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
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a switchover of control is attempted before equilibrium is achieved. This bumping problem is said to have been solved with a new reset bypass controller developed in conjunction with the Syncro. T h e new- controller permits manual loading pressure to the valve to be impressed instantly, fully, and continuously on the reset reference chamber of the controller. Multiple-Loop Control. Simplicity of switching inherent with the new line of Syncro stations is not restricted to single-loop controls. It provides the same important advantages with cascade and multiple-loop controls, for which switching normally requires complex, time-consuming procedures. A Mini-Syncro cascade station can be operated in either cascade or automatic control on the secondary controller, or on manual. Alternately, it can allow control in cascade, independent on primary, and manual; or it can allow the control point to be set remotely-as from a computer-or allows independent control at the station, or on manual. All cascade Syncro stations have two switches. One switch allows instant bumpless transfer between automatic and manual control. T h e second switch allows a choice of the automatic mode of control, which can be made when the station is in the manual position. T h e switches are interlocked mechanically to prevent the operator from changing the automatic mode of control inadvertently. I n addition to the standard loop and cascade versions, the MiniSJncro is available in a version which consists of a vertical gage, a single switch and one Syncro. IYhen this configuration is in the automatic position, a remote signal passes through the switch while the Syncro keeps itself aligned to the incoming signal. I n the manual position, the switch permits the Syncro output to pass through the switch. This version of the Mini-Syncro may be adapted for use with conventional control systems of any type to utilize Syncro-safe switching, at least in the automatic to manual direction. Station Configuration. A red pointer on the main gage of each basic Syncro indicating station indicates the control point. A black pointer on the same gage indicates
I
-320°F +400°F
he process variable. Continuous galve-pressure indication is pro&led on each Syncro station, in:luding the Syncro recording stations, by a separate (horizontal) valve gage. Simplified panel design allows three rack-mounted Mini-Syncro indicating stations to fit in the same size cutout used for one three-pen, miniature recorder. Several MiniSyncro stations may be gangmounted, as a pre-assembled package, nesting flush at the top, bottom, and side against each other in a single rectangular cutout. Moore Products Co. 201 PRESSURE INDICATOR
THE PROBLEM: Control hard-to-handle fluids such E nitrogen tetroxide (N204),cryogeni fluids, strong acids and bases.
THE SOLUTION:
Victor inline pressure regulators . constructed o f corrosion resistar stainless steel with a unique inlin piston design. The inline design pe mits the use of special Teflon seal that effect a tighter seal as pressur increases and as the permeating flui softens the seals. The straight through flow path of th inline pressure regulator produces hig flow capacity relative to size, and loi lock-up to flow pressure differentia
Inlet Pressure: to 15,000 psig Line Size: Viffto 8ft Flow Capacity: to 2,750,000 scfm of air For additional information, write or cal
**
** VICTOR EQUIPMENT COMPANY-CONTROLS D l V l S l l 2336 Auburn Blvd., Sacramento, California 95821 Tel: (916) 482-9884
For development or production Bpplication, direct reading pressure indicator covers full-scale ranges from 0-0.1 p.s.i. to 0-500 p.s.i. Pressure sensor consists of resistance-type transducer with convenient mounting configurations and pressure connections. Through use of transistorized circuitry and self-contained long life batteries, indicator box may be located remote from sensing position. Three-position switch selects degree of sensitivity: 1 0 0 ~ oIO%, , and 1% of full scale. Millitest Corp. 202
check coupon for applications that interest you TAM zirconium compounds are amazingly powerful bonding agents with an extremely broad range of applications. How will they help you i n your industry? TAM Product Data Sheets and Technical Paper on Zirconium may open new doors for economically improving your product or process.
FLOW MET ER
Using high sensitivity strain gage transducer system, new Mark V flowmeter produces output signal that is linear with flow rate. Useful range is u p to a maximum of 22 g.p.m. Ramapo Instrument co. 203 H I G H TEMPERATURE L I M I T I N G DEVICE
Nonindicating high temperature limiting device used in conjunction with separate temperature control provides for safety shutdown of heated process equipment or cutoff of heat supply at predetermined temperature within an overall range of -30" to +llOOo F. Trip-free switch fails to function if a reset button is tied or welded down, and it can be manually reactivated only after temperature has dropped below high-limit setting. Instrument carries cover-mounted red signal light which remains "on" during normal operation. Light is deenergized when high-limit switch is actuated. T h e Partlow Corp. 204 ( C o n t i n u e d o n p a g e 98)
Circle NO. 29 on Readers' Service Card
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American Cyanamid Company's modern acrylic fiber plant near Pensacola, Fla.
We count at least Because its salts are characteristically white or colorless, aluminum guards against color contamination. This reason alone could account for the wide use today of Alcoaa Aluminum in the production and handling of polyethylene, polypropylene, polystyrene, vinyl acetate, vinyl chloride and other olefins and polyolefins. There are many other reasons-including light weight, strength in alloys and high resistance to corrosion-that contribute to reduced costs. One increasingly important olefin is acrylonitrile, used as an intermediate in the preparation of dyes, pharmaceuticals and insecticides. With its
96
places Alcoa Aluminum
polymers and copolymers, i t is used directly in the formulation of fibers, adhesives, rubbers, plastics, insecticides; and in the treatment of textiles, leather and paper. Aluminum is resistant to acrylonitrile, and to its raw materials as well.
56 places aluminum saves money in a modern American Cyanamid Company acrylic fiber plant Organic storage: tanks and jacketing. Inorganic storage: jacketing on solvent tanks, stair treads. Utilities area: conduit, roofing, stair treads, deionized water piping and storage tank.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Solvent recovery: conduit, jacketing, stair treads, grating, armored cable, waste dope storage. Monomer blend area: tanks, piping, instrument tubing. Reactor area: deionized water quench tank, catalyst storage tanks, screen tanks, reactors, polymer slurry pipe, feed chutes, manholes, stair treads, grating, ventilation exhaust stack, meter vent pipe, window frames, flashing. Maintenance building: gutters, flashing. Pilot plant building: blowout panels, duct work, flashing, stair treads. Drum storage building: siding. Manufacturing building: flashing, stacks, exhaust ducts, weak solvent tank, jacketing, stair treads, grating, slurry filter vac-
Aluminum grating and stair tread on reactor structure.
Aluminum quench tank and grating at acrylic fiber plant.
Aluminum tanks and piping handling acrylonitrile monomer solutions.
saves money in an acrylic fiber plant uum pipe, polymer slurry pW adjustment tanks, polymer slurry feed tanks, distilled water lines, polymer slurry storage tanks, duct work, angle supports, instrument tubing, control panel, dope storage tanks, plate and frame filters, structurals on final coolers. Your Alcoa representative has more information-facts and figures proving how aluminum cuts maintenance and operating costs while protecting product purity. Call him in. We’d like to send our booklet, Process lndustries Applications of Alcoa Aluminum. Write Aluminum Company of America, 964-H Alcoa Building, Pittsburgh, Pa. 15219. Alcoa Brings You America’s Finest News Show, THE HUNTLEY-BRINKLEY REPORT, on NBC-TV
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. Circle No. 38 on Readers’ Service Card VOL. 5 7
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Isn't Brookfield the real logical solution to your rheological problems r)
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1ITERATURE
Indicating Pyrometer. Catalog gives detailed descriptions of indicating thermo-electric pyrometers: Model 1528 for indicating temperatures of one sensing element; Model 10322, vertical rotary switch type to measure several points; and vertical connector panel type with plug and six jacks and panel for rapid switching, accurate measurement, and single or multipoint checking. Thermo-Electric Co. 205 Air Analysis. Brochure describes instruments and systems that continuously monitor atmosphere for major air pollutants, such as nitrogen oxides, sulfur dioxide, hydrocarbons, ozone, carbon dioxide, and carbon monoxide. Integrated, computerized data handling systems, as well as individual instruments, are described. Beckman Instruments, Inc. 206 Solenoids. Catalog describes low-cost, U frame actuators for light duty applications and precision cylindrical units for close spacing and extra long life. LIiniature cylindrical solenoids described are for both continuous and intermittent duty where size and force are relatively small. Artisan Electronics Corp. 207
Alcohol to Asphalt range-System measures viscosities from less than 1 to 64,000,000 centipoises. Works in non-Newtonian, Newtonian and nonflowing (plastics, gels, se m i -ge I s) m a t e r i al s. Small-sample (1 cc), hot-or-corrosive-sampl e, temperatu re-controlled and sealed-from-atmosphere capab i I i t ies. Easy to use-Just i m m e r s e , start, read. Direct-reading in centipoises, absolute units most useful to others. Readily portable-Easily maintained. Accurate to C 1% of full scale. Backed by service far beyond the sale.
ENGINEERING LABORATORIES, INC.
Moisture Monitor. Handbook describes electrolytic moisture monitor, electrolytic cell characteristics, sample system design tips, recommended f l o w control technique, calibration methods, anomalous samples, and literature references. Also included are curves and useful nomographs to relate moisture, dew point, relative humidity, absolute humidity, and other moisture measurement scales. Consolidated Electrodynamics Corp. 209
M o r e information is as near as your mailbox. Just circle the number of the item in which you are interested on the Readers' Information Card.
Stoughton 61, Massachusetts Circle No. 8 on Readers' Service Card 98
unreactive can a DrOduCt be that has 55 reactions, - -
and 80 literature and Datent references?
Sodium Ion Analyzer. Brochure describes sodium ion analyzer that automatically determines sodium content in p.p.b. range. New unit is a potentiometric instrument employing simple electrode system sensitive to low levels of sodium in aqueous solutions. The instrument gives continuous recording or direct meter readout in any of three decades of concentration from 1 p.p.b. to 10,000 p.p,m. Beckman Instruments, Inc. 208
Write for our new, illusfrafed cafa!og, today!
HOW
INDUSTRIAL A N D ENGINEERING C H E M I S T R Y
Not a bit. And this new cyanuric acid technical bulletin brings you all the facts about these reactions, applications and references. For your copy of this revised 22 page data sheet, write to the Product Promotion Dept.
FMC CORPORATIQN INORGANIC CHEMICALS DIVISION 833 THlRD A V E N U E N E W Y O R K N Y
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