the cathode; the last one, the anode. Each of the nine compartments in be tween contains an auxiliary electrode which can function as either an anode or a cathode. All electrodes are iso lated from the material to be fraction ated by dialysis tubing. Flow from one compartment to another is through small diameter openings. The electrolyte used is 0.05M sodium sulfate. First step in carrying out a typical separation is making the p H gradient. This is done by setting the potentiom eters, which are connected to the auxiliary electrodes, for the desired ρ Η value. Next the lyophilic mate rial is pumped into the addition com partment. As the material enters the system, its various components mi grate to the compartments that have the p H of their isoelectric points. The p H gradient can be regulated to separate out one of the material's com ponents or all of them, Dr. Donnelly points out. Monitored. The p H of each com partment is monitored periodically and maintained at the desired value automatically. Monitoring is handled by a p H electrode device which tra verses up and down the length of the cell system and measures the p H of each compartment. Before each measurement, the current is cut off and the compartments sealed off from one another automatically. The ρ Η meter transmits the measurement to the ρ Η controller unit. This unit compares the reading to the potenti ometer setting. Then if the p H is low, the controller unit initiates ac tion to raise it. The ρ Η is increased by operating the auxiliary electrode as a cathode. If the p H is high, the electrode becomes an anode. Best results are obtained, Dr. Don nelly finds, if the cell system is oper ated at 26° F. Because the system requires high voltage (700 volts at 50 to 100 ma.), much heat is generated and cooling is necessary to avoid dam aging the lyophilic material. The cell is jacketed and there is also a cooling tube through the cell. Coolant used is an ethylene glycol-water mixture. The lyophilic material itself is dis solved in a glycerine-water mixture. Swift's interest in lyophilic material and its fractionation stems from the fact that the company is a large con sumer of enzymes for tenderizing meats. Swift also has great interest in basic and applied aspects of animal and vegetable proteins. 58
C&EN
MAY
2 4,
1965
Papermaking No Longer an Art Mead computer installation is case in point of shift from art to engineered operation Papermaking has crossed the threshold between a highly developed art and a highly engineered technology. Pushed by the computer and pulled by eco nomics, paper machine operation is succumbing to automatic control at a rapidly increasing rate. The most detailed case in point to date is that of Mead Corp., which has revealed successful operation of an IBM 1710 computer control system at the Ohio mill of its Chillicothe Paper Co. division (C&EN, May 10, page 22). But Mead is only one of about a dozen paper companies currently in some stage of computer operation, although the only other U.S. company to announce successful results so far is Harding-Jones. The benefits that engineers are driving to achieve through computer control are product of more uniform quality at maximum profit, greatly re duced order change time, and more efficient machine operation at high speed. Ability to make small orders economically on large, high-speed machines having multiple stock sys tems, optimum design of new ma chines, and multiple-machine opera tion by a single crew are other bene fits that now seem attainable in the future. It's becoming quite clear that papermaking machine operation in the next few years will undergo many major changes as it enters the era of com puter control, J. D. Maloney, associate director of Mead Corp.'s central re search laboratories in Chillicothe, Ohio, points out. But it's important to realize, Chillicothe's assistant di vision manager O. C. Christiansen emphasizes that a computer is just one factor—although a major one— that will lead to greater operational control. Focus. When computers are used, papermakers—from research workers to machine operators—must focus more clearly on what variables need con trolling to create an optimal oper ation. Procedures must be refined all along the line to get maximum benefit of the expensive computer op eration. Thus, it isn't fair to attribute to the computer all improvements in
a papermaking process under com puter control. Mead's experience, Mr. Christiansen says, indicates that much of the bene fit of such a program is the careful and systematic standardization of the whole papermaking operation. The computer can then aid in maintaining and improving the operation. What this operation consists of is a series of steps that comprise the wet end of the machine—the part ahead of the dryers. At Chillicothe, this begins at the machine chest, which holds the pulp slurry. Pulp feeds from here to Jordan refiners, where it is broken down. Clay filler is added to the slurry, which then passes through cleaners and into the head box, from which it feeds onto the Fourdrinier screen. Affect Quality. The variables in this part of the operation and their effect on product quality are for midable. Refining, for example, in creases sheet density, and burst, ten sile, and fold strength, and it decreases tear, stretch, opacity, brightness, and porosity. Fillers increase opacity, brightness, bulk, flexibility, softness, weight, smoothness, and levelness, but they also decrease sheet strength. Achieving a proper balance of such properties in a given paper grade is what has constituted an art. But the old arguments that not enough is known about papermaking processes or that there are too many variables which can't be measured to make com puters feasible are the very arguments that justify their use, in Mr. Maloney's opinion. The essential elements of a program for adapting computers to papermak ing can be expressed in four words: stabilize, standardize, computerize, and optimize. The focus of this effort at Chillicothe was the No. 4 machine, which produces a variety of uncoated offset and letterpress grades. Before any thought was given to actual computer control at Mead, Mr. Maloney says, paper machine oper ation was stabilized as much as pos sible and a standard operation achieved for each grade of paper. This is an important first step in such a
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program to obtain meaningful data correlations. Statistical models are now being developed at Mead for use in feed-forward or adaptive control. Ultimately, process optimization and maximum usefulness of the process control system are anticipated when the computer becomes part of a total management information system. Stabilizing the papermaking process involves a comprehensive engineering analysis from one end of the operation to the other. Thus, Mead added many new instruments to the system, particularly for measuring and controlling flow in the stock preparation area and the Fourdrinier. Engineers checked existing instrumentation to determine whether the sensors were properly sized and in good working order. The computer was invaluable for collecting and analyzing data during this part of the program, Mr. Maloney says. Broader. The standardization phase of the program is much broader than just establishment of manufacturing standards for operation of the various processes. It includes the use of computer techniques for supervisory aid and operator guidance in which there is no direct control link from the computer to the paper machine or other equipment. For example, a computer alarm program replacing a straight logging of data was put in use early in the project
by Mead to provide the operator with information on an exception basis. In developing the program, a set of limits was first determined for important variables such as temperature, flow rates, power, consistencies, and water and stock levels. Base values for the variables are cued to the computer when the operator is satisfied with machine operation. Deviation beyond the limits results in a message to the machine tender giving him the time, the variable name and measurement, the deviation, and the correct reading. Correction of the condition is at the discretion of the machine tender. Mead is now using a manufacturing standards program only around the wet end of the process. However, it is applicable to all machine variables set by operators. Standards were developed by systematically collecting data during standard good operation. This is a condition defined as general agreement that quality is satisfactory and that the machine has settled down. Mr. Maloney says that the data show a rather broad range of operation that produces satisfactory paper of a given grade and weight. Mead has standardized 23 variables on all grades run. Machine operators have generally accepted these standardizations, Mr. Maloney says, because they see that it makes for a better operation. Paper formation,
for instance, is more uniform because jet velocity at the slice is automatically synchronized with wire speed. Only after a process has been stabilized and standardized is it ready to be computerized, Mr. Maloney believes. There are three areas in which process control is needed on a paper machine. These are normal control of variables during steady-state operation, cross-machine control (of basis weight, moisture, and caliper, for instance), and dynamic control relating to start-ups and grade changes. One Loop. At present, basis weight is the only computer closed-loop at Mead. The computer replaces an analog cascade controller by changing the set point of the stock-flow controller based on an in-line basis weight measurement at the dry end of the machine. However, a similar control of moisture resulting after the last dryer section is in the final stages of development at Mead. Although only one loop is closed, the computer is being used to control several loops in a supervisory manner during grade changes. This is being accomplished by using standards and suitable control strategy involving order, magnitude, and time of variable changes. After a study of exactly how the operator makes a grade change, computer logic was developed to duplicate this method. Mead scientists were then able to develop relaMAY
2 4,
1965 C & E N
59
g
To Dryers,..
ACCESSORIES BROADEN VERSATILITY OF PERKIN-ELMER LOW-COST SPECTROPHOTOMETERS
tively simple equations which they use to go from one set of standards to another during basis weight and speed changes. This is a powerful tool for keeping the wet end under control as machine speeds are increased, and it allows the operator to handle other aspects of machine operation. The real value of digital computer control, Mr. Maloney says, seems to Known all over the world as primary tools for regular daily chemical anal be its ability to use statistical models yses, Perkin-Elmer's low-cost spectro in a feed-forward control scheme. H e photometers are equally adaptable hopes that the amount of drift inherent to unusual applications through the in the approach will be slow enough so use of special accessories. Here are that normal off-line test information some of the sampling aids developed can be used to correct the models. No for the NaCI prism Model 137B, the controls of this type are in operation KBr prism Model 137B, and the grat at this time on Mead's No. 4 machine, however. ing Models 137G, 237B and 337: Although much can be done to Micro Cells for work with limited optimize the papermaking process, the sample volumes of liquids and solids ultimate optimization requires a tie-in in solution, where precise quantita of the process control computer sys tive and qualitative information is tem with management information sought. As little as 25 /xg of sample systems. In this way, dynamic cost may be used. accounting and other information can Small-Volume (25 cc) Gas Cell for be made available on a real-time sample-limited gas analysis. A 75 basis to the process control computer cm path is provided. optimization programs. In turn, ma Beam Condenser for micro-analy chine status and production statistics sis of extremely small solid samples are needed by the management in in KBr pellets. As little as 1 /xg may formation system for effective schedul be detected. ing and production control. Mr. Ma For details on the full selection of loney says that Mead is already mov accessories for P-E low-cost IR spectro ing well along in this direction. photometers, write to Instrument Divi sion, Perkin-Elmer Corporation, 7 0 7 Main Avenue, Norwalk, Connecticut.
BRIEFS
Pump Handles Coolant At High Temperatures
PERKIN-ELMER ^0
C&EN
M A Y 2 4, 1 9 6 5
The pump consists of a direct-cur rent, liquid-metal, conduction-type unit powered by an integral thermo electric direct-conversion generator. The thermoelectric elements extract heat from the fluid being pumped, convert part of it directly into electric ity, and deliver the electricity to the conduction pump. The conduction pump portion of the unit consists of electrodes mounted on opposite sides of the channel through which the liquid metal is pumped. Permanent magnets create a mag netic field perpendicular to the electric current passing through the liquid metal. The resulting pumping force on the liquid metal is proportional to the electric current, the magnetic field, and the width of the fluid chan nel. Heat flowing through the thermo electric elements may be rejected by radiation to the surrounding environ ment, or by conduction to a liquid coolant. The thermoelectromagnetic pump being sold by Atomics International is 1 ft. long and weighs 45 lb. It can pump liquid metals at temperatures to 1300° F., and has a design lifetime of 10,000 hrs. Standard metallic thermoelectric elements are made of Chromel and Constantan. Ε 35
A pump for handling high-temper ature liquid metals has been developed at Atomics International division of North American Aviation, Inc. The Canoga Park, Calif., company says that the unit, called a thermoelectromagnetic pump, has no moving parts and needs no separate electrical power hookup. Atomics International has been suc cessfully building and operating differ ent types of thermoelectromagnetic pumps for about five years for the Atomic Energy Commission's SNAP reactor program. For example, a 500watt(e.) SNAP 10A reactor system was placed in orbit last month and is operating at full power. This system uses liquid sodium-potassium as the reactor coolant. It is pumped at about 14 gal. per minute by a pump that's similar to the thermoelectro magnetic pump Atomics International is now producing.
A food additive regulation prescribing the conditions for safe use of 1,3butylene glycol (1,3-bg) in food flavorings has been issued by the Food and Drug Administration. The fourcarbon diol, currently produced only by Celanese Chemical in the U.S., has potential use in food processing, artificial flavoring, extracts and food colors, as well as pharmaceuticals and cosmetics. FDA has previously issued regulations prescribing the conditions for safe use of 1,3-bg as a humectant in cellophane and as a component in adhesives.
General Motors will establish a test facility at Los Angeles to monitor exhaust emission of its 1966 automo biles and light trucks. The test facility, expected to be in operation by the start of the 1966 model year, will serve as a production quality control center. Opening of the test installa tion coincides with the production of the first GM cars in California with the Air Injection Reactor System.
Pardonable puffery: oo
it's Isopar®
(Other new process and formula uses are even more eye-opening !) Most visitors to the World's Fair don't know that those big General Cigar smoke rings are really Isopar — Humble's brand name for a new family of synthetic hydrocarbons — chosen here for nontoxic and quickvaporizing properties. In many ways, in many indus tries, Isopar turns up in jobs that may even surprise you . . . In polyolefin and stereo rubber manufacture, Isopar is boosting catalyst life and activity, giving greater polymer yield, because it's so free from olefinic im purities and trace contaminates. And selected grades have FDA permission in food-related and certain direct food uses. In organosols, Isopar is giving better control over dispersion viscosity . . . improving viscosity stability . . . facilitating application. In rubber adhesives, Isopar is reducing solvent consumption, speeding solvent release, reducing heat requirements, giving lower solution viscosities. In odorless paints, Isopar is making superiorperforming enamels and flats. In cosmetics, Isopar ends problems of greasiness; gives hair preparations better manageability, cleansing creams greater cleansing action, and foundation makeup a more natural matte finish. In aerosols, shoe polishes, household dry cleaner, photocopy developer, in chlorination processes . . . but that's why we use the infinity sign with Isopar. Get the full story about Isopar in your field from our local Solvents Representative — over a good cigar. Or, if you prefer, write to our Solvents Sales Department in Houston, Texas. H U I V I B L E . . . AMERICA'S LEADING ENERGY COMPANY. .. FIRST IN RESOURCES / FIRST IN CAPABILITY OIL & REFINING COMPANY
£sso C&ΕΝ
61
C&EN
INDUSTRIAL smam
PROGRESS REPORT
SPECIALTIES
These items have all been mentioned editorially in C&EN in the past month. If you haven't already sent for information on them, just check the appropriate key numbers on the coupon on page 64, and C&EN's Readers' Information Service will forward your request to the manufacturer. Product
1
Adhesive (Polyflocktex) Insecticide (Golden Uran) Silt control (CL-45) Butyltin derivatives
C63
Colorants
C64
Additive (Dacovin 3021) Rinsing aid (Entek 47) Antioxidant (Irganox 1010) Polymer (Gantrez AN 8194) Textile size (Appretan N) Coating (PT201N) Protective coatings (Turco Guard and Sure Guard) Release agent
C65
C60 C61 C62
Emulsion (Resin D-869) Furnace black (United 3007) Polyester carrier (Valcar462) Available
in commercial
C66 C67 C68 C69 C70 C71 C72 C73 C74 C75
quanlilies
unlet s otherwise
Last August, G M notified the Cali fornia Motor Vehicle Pollution Con trol Board it would install the system on 1966 high-volume-production ve hicles for sale in California to ensure that their emissions are within Cali fornia standards.
An air pollution program for East Chicago, Ind., is under way with the announcement that Inland Steel and Youngstown Steel will install antismoke controls. An agreement that calls for full control of open-hearth and sintering plant facilities, has been signed by the city and the steel companies. Installation of the control facilities will be phased in in steps. The program calls for use of electro static precipitators, high-energy wet 62
C&EN
MAY 2 4, 1965
Company
Adhesive Products Corp. Bronx, N.Y. Allied Chemical Corp. New York, N.Y. Calgon Corp. Pittsburgh, Pa. Carlisle Chemical Works Reading, Ohio Claremont Polychemical Corp. Roslyn Heights, N.Y. Diamond Alkali Co. Cleveland, Ohio Enthone, Inc. New Haven, Conn. Geigy Industrial Chemicals, Inc Ardsley, N.Y. General Aniline & Film Corp. New York, N.Y. General Aniline & Film Corp. New York, N.Y. Product Techniques, Inc. Los Angeles, Calif. Pu rex Corp., Ltd. | Wilmington, Calif. Ram Chemicals, Inc. Gardena, Calif. Shawinigan Resins Corp. Springfield, Mass. United Carbon Co. New York, N.Y. United Merchants and Manufacturers, Inc. New York, N.Y.
Features
For flocking on polyester Parathion concentrate for use on corn rootworms Prevents build-up of water foulant ma terials in industrial cooling water Biologically active derivatives to control growth of microorganisms Lead and nonlead synthetic pearl es sences for internal coloring of plastics For the production of clear, blow-molded polyvinyl chloride bottles Provides film to protect metal parts from water staining and tarnish For use in polypropylene, polyethylene, and SBR and natural rubber Development quantities; undergoes cross-linking and complexing Requires no additives and gives rapid wetting of nylon fibers To protect enclosed metal parts from acids, alkalies, and solvents For painted or unpainted metal surfaces Experimental quantities of agent for clean-parting of materials Development quantities; can be com pounded without phase separation Medium-size-particle black for printing inks Readily dispersed nontoxic liquid for dye houses with open equipment
noted.
scrubbers, or filtration systems. It also provides for abandonment of obsolete facilities with or without their replace ment by more modern steelmaking processes, which incorporate air pol lution controls.
Dow has licensed Montecatini's poly propylene patent holdings. The non exclusive license agreement makes it possible for Dow to make and sell polypropylene resins, films, and heavy monofilaments in the U.S. under Mon tecatini's patents. Included in the agreement aie three composition of matter patents and one catalyst patent. Montecatini also has licensing agree ments with Hercules, Shell Chemical, and Novamont, a U.S. subsidiary of Montecatini.
NEW EQUIPMENT Metering pump with repetitive ac curacy of ±1% of preset flow is avail able from Hills-McCanna Co. (Carpentersville, 111.). The positive-dis placement pump is actuated by an enclosed actuator and heavy-duty clutch operating in a sealed oil bath. The pump, McCannaMatic, is de signed to inject additives into gasoline, chemicals, and other products. Ε 3 3
D-F-M fluorocarbon beakers are now being offered in a new design of Griffinform by Cresap Research & Devel opments, Inc., of Mt. Kisco, N.Y. The compact, sintered vessels are available in 250-, 400-, 600-, and 1000-ml. sizes. Ε 34
Oxygen analyzer for concentrations from 2 to 30% has been introduced by Union Industrial Equipment Corp. The Fall River, Mass., company says the Unico 707 provides a rapid, ac curate means of measuring the oxy gen concentration in chemical proc esses, combustion processes, inert at mospheres, and similar conditions where oxygen concentration must be known. Ε 30
Series of electrically controlled pres sure regulators has been developed by Victor Equipment Co., of Sacramento, Calif. Originally designed for use in the aerospace industry, ER and ERR Series regulators are useful to chemi cal and petrochemical, industrial gas, or liquid control systems, Victor says. The regulators are available for pres
sure ranges to 10,000 p.s.i.g. and flow rates to 175,000 cu. ft. per minute. E31
High-precision electromagnet with 12.5-in. pole tips is available from Alpha Scientific Laboratories, of Berke ley, Calif. Model 1200 is designed for high field strengths for use in highresolution EPR, NMR, and magnetoacoustical experiments. The unit sells for $7250, according to Alpha Scien tific. Ε 32
Further information on keyed Chemical and Equipment items is readily available . . .
| I j
Use handy coupon on page 64
\
I
7
May 24, 1965
Readers Information Service
Use this handy self-mailer to obtain further information or literature. Simply mark the items desired, fill out the information requested, clip the coupon, fold, staple, and mail.
Name: Company:. Street: -Zone
City-
-State-
Your Title:-
POLYFUNCTIONAL MERCAPTANS Carlisle's MERCAPTATE* Esters provide a new means of modi fying p o l y m e r i z a t i o n reactions. T h r e e m e m b e r s t y p i c a l of t h e series are pictured above. Other k n o w n uses include plasticizers, curing agents, and polymerization modifiers. Perhaps you have still another. PROPERTIES
YOUR FUNCTIONS (Maximum of 2, please.) Α Β C D Ε F
Π Π Π Π Π Π
Management Process Research & Development Product Research & Development Basic Research Plant Operations Engineering Design & Construction
GΠ ΗΠ I • J Π ΚΠ
Analysis/Testing Marketing/Sales Purchasing Consulting Teaching—Student
The MERCAPTATE Esters are high-boiling, vis cous liquids. They have sharp, sulfur-like odors. They are insoluble in water and the alkanes, but are soluble to varying degrees in other organic solvents. Reactions of the MERCAPTATE Esters are typi cal of both the mercaptan and the ester.
AVAILABILITY CLIP COUPON—Fold along this line—fasten (staple, tape, glue) MAIL Your Industry:
A Β C D Ε F G H I J
( ( ( ( ( ( ( ( ( (
) ) ) ) ) ) ) ) ) )
Engineering and Construction Food and Kindred Products Textile Mill Products Paper and Allied Products Government Chemicals and Allied Products Elastomers, Polymers, Plasticizers Drugs Detergents, Cosmetics, Specialties Paints, Varnishes, etc.
Κ ( ) Petroleum Réf., Asphalts, Lubricants L ( ) Rubber and Plastic Products M ( ) Independent Laboratories Ν ( ) Consultants 0 ( ) Primary Metal Industries Ρ ( ) Fabricated Metal Products Q ( ) Machinery and Equipment R ( ) Transportation Equipment S ( ) Instruments and Controls Τ ( ) Education
Six types of MERCAPTATE Esters are avail able immediately in development quantities. Detailed information on MERCAPTATE Esters is carried in Bulletin D-103. Write for a copy. Better still, if you would like to discuss your needs, call us at area code 513, 821-3660, and ask for Bob Witman or Paul Thompson. *T.M.,C.C.W.
CARLISLE
CHEMICAL WORKS, INC.
^tC*^ READING, SPECIAL
DEPT. C-53 OHIO 45215
CHEMICALS
MAY
FOR
2 4, 1965
INDUSTRY
C&EN
63
