I&EC REPORTS & COMMENTS 1
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Chemical ideas for parking meters Plastics for European housing New cryogenic valves Upgrading undergraduate study
CHEMICAL TIMER A new idea proposed lo make the parking . . metm obsolete Do parking meters frustrate you? Recently we saw an ad for a tiny mechanical timer to attach to your car key ring. This could be set to buzz a warning up to one hour, keeping you from getting to your car a minute too late, to find the officer already writing a ticket. But that doesn't solve the problem of not having the change to use the meter. A stamplike chemical timer described in a patent owned by Felix D. Kolben of Chicago, Ill., is an interesting solution. His idea for control of parking is a simple timing device that would stick to a windshield, activate easily, and indicate time by changing color. Dr. Laszlo F. Biritz of Armour Researc.h Foundation, the inventor, developed prototypes that'work. He used free radicals, paper and tape, and air to create a system using strips of chemical timer (U. S. Patent 3,018,611). Prototype models of the timer contain the free radical tri-p-biphenylylmethyl as the chemical reactant, although other free radicals could be used. The dark, olivegreen compound is stable until it is exposed to oxygen. Then it converts to colorless peroxide at a very high rate. T o use it as the basis for a timer required three steps: construction to prevent air from reaching the free radical during handling and storage; a means of easily activating the timing cycle; and a method of controlling decolorization rate. Assembly of the timer starts with a coat of the tri-p-biphenylylmethyl on a soft, loose-textured filter paperunder ineit atmospheric conditions, of course. Transparent cellophane tape hermetically seals the strip of
filter paper to a backing of pressuresensitive tape. The basic element of the timer can now he handled and stored in air. The timer is activated by letting air through a pinhole at one end of the timer strip. A removable tape over the hole keeps air out until the device is used. Since reaction of tri-p-diphenylylmethyl with oxygen is very rapidasiit must be to give a sharp transition from unreacted dark areas to oxidized colorless area-ome ratecontrolling step is needed. Control of air entry and diffusion was the answer. A pinhole of proper diameter allows air to enter at a slow rate. As the oxygen in the air diffuses through the loose filter paper, it rea& with free radicals. Diffusion is slow and the edge of the diffusion area is sharply defined. Thus short strips of timer permit practical timing periods. For instance, a layer 55 mm. long with a pinhole opening of 0.1 to 0.08 mm. can last 29 minutes. At normal ambient temperatures, the timer is accurate to one minute. Accurate timing despite temperature differences is a strong point of the device. Temperature independence is possible, within limits, since two rate-controlling factors depend on temperature in different ways. Gas flow through a small hole is
inversely proportional to temperature, and gas diffusion (inside the device) is directly proportional. By using proper diameter of the pinhole and cross section of the reacting layer, the effect of temperature can be greatly diminished. For the above example, pinhole diameter was 0.1 to 0.08 mm. and filter paper strip was 10 mm. wide. At 36" C., the decolorization time was 29 minutes; a t 70" C., 21 minutes. Control and calibration, using such parameters as pinhole size and numben,paper dimensions, and possible use of other free radicals, give the timer flexibility. Performance can be changed to match operating conditions and requirements. Manufacture appears to he feasible, and the product would have properties amenable to the marketplace. Chemical timing stickers would be small, convenient to use, and should be dependable. Used to control parking, they would not require the heavy investment, service, and collection outlays that parking meters do. Other practical uses are possible. Stamps could be used to time the heating of precooked frozen foods. Industry could use them to time construction details such as the setting of cement or adhesives.
BUILDINB OFFERS HOPE FOR EUROPEAN PLASTICS PRODUCERS Use of plastics in building may offer hope to European plastics producers. This potentially vast market can, in the long run,turn out to be a major answer to growing overcapacity problems. Increasing penetration of modem thinking on ancient building codes was obvious in Europe this spring. Examples: Italian city of Brescia has decided to okay the use of PVC pip(Cartimed os poga 70) VOL. 5 4
NO. 7
JULY 1 9 6 2
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I&EC REPORTS
COMPLETE CHEMICAL RESISTANCE & FULL-VIEW FILTRATION UP TO 250” F. Sethco versatile filter systems wear niany “hats” to serve full time i n chemical, plating and other fields. ,and pay their way many times over in efficiency and savings. Typically, the UAA and UPP models have high acceptance as reliable cost reduction systems for continuous filtration, agitation or transfer. Unique, “module” design, with independent pump and filter chamber, permits use of a multi-duty Sethco unit at any tank location, at any time as needed. One investment i n a Sethco ‘In-Tank’ Pump-Outside Filter System eliminates the need for costly, bulky equipment and literally clears the deck for action. Tell us your particular application for a more detailed reply.
Write or call today for BULLETIN 851C.
2275 Babylon Turnpike, Merritk, 1. I., N. Y.
Circle Nor. 39, 40
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ing for its gas and water supply systems-a significant and promising. move. Italians often say that guardians of the building codes still think that housing, public sanitation systems, and the like must be built to last 500 years, a noble goal but rather uneconomical. It means that rather than build for one generation, they don’t build a t all. In Germany, meanwhile, the general product area “Bauwesen,” loosely translated to mean construction, took just about one fourth of the country’s plastics consumption last year. Further, about 77& on the average of the cost of German houses is for plastics. This could easily be doubled, the plastics industry feels, if the advantages of plastics were systematically utilized. At the 1962 Hannover Fair, t h e German industr)- bepan to push hard in this direction. The new Chemie und Kunststoff Halle, completed just in time for the Fair, used plastics extensively in its construction-plumbing, facades, floor coverings, adhesives-and was filled with exhibits of plastics for building. I n France, the Exposition Europlastique continued the theme. At the Italian Milan Fair, plastics producers pushed the point. And one of the chief spokesmen for the Italian chemical industry, Dr. Luigi Morandi of Montccatini, publicly stated at the Milan Fair that what the Italian industry needed most to cope with its bothersome overcapacity in plastics was better market development and use development in---you guessed it-building as one of the most promising sectors. But progress, despite this industrial interest, is slowed by the lack of standard building codes, not only from country to country, but also from city to city throughout Europe. Some authorities turn a very sympathetic ear to supporters of plastics: others are not prepared to modify building codes which, to them, have been proved by experience. Such steps forward as the Brescia decision, the intensified R&D to
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I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
satisfy building authorities and potential users, and the growing backlog of successful applications all point toward the success of the industrial pressure to increase plastics consumption in building. European and American expcrience$ in this field seem remarkably similar and offer the same hope for helping the overcapacity mess.
FROM CAPE CANAVERAL TO THE CHEMICAL INDUSTRY Equipment that plays a key role in the U. S. missile and space program is making a bid to solve industrial problems. \\‘ith industrial use of liquefied gases on the increase, some of the problems facing space scientists are starting to plague chemical processors. \.$’hat may be more important is that experience gained in meeting the exacting specifications of the missile field can also be used to satisfy some of the less demanding requirements of temperature, pressure, and corrosivit>-in the CPI. Flodyne Controls, Inc., of Linclcn, N. J., itarted making. cqogenic valves about two years ago and currently produces valves used in rocket work at Marshall Space Flight Center (Huntsville, Ala.) and on Cape Canaveral. Success of the support and launch
This fiicture shows relative sizes of 7 / 4 > 2-, and 4-inch valves. The $-inch ball valve, mcuum-jacketed, handles liquid helium and hydrogen. A 2- 7/2-inch stainless sieel ball m l o e is designed f o r helium service at 6000 p.s.i. As an indication of openin,y sfieed: Flo4yne’s 7-inch ball ualie i b r 3000 p.s.i. helium seroice opens in less than 50 msec. (Continued on @?e 13)
New 10”pipeline homogenizer ,E >i&
provides efficient, high-volume, air-free mixing without a tank. New 30 to 60 h p HOMO-MIXER, largest standard pipeline h o m o g e n i z e r , uses proved Eppenbach mixing head. Reco m m e n d e d for dispersing p i g m e n t s , catalyzing resins, blending or dispersing in volatile n~aterials,etc.
Operating principle High-speed turbine-rotor draws product in, shears it in fine clearances between rotor and stator, and forces it through restrictive openings in stator. Intense impact and hydraulic shear breaks down agglomerates, quickly wets out and disperses finest solids.
Advantages
LOW initial cost. Mixing tank or vessel is eliminated. !hVeS space. No tank. Unit can often be installed in place of elbow in present piping.
High efficiency. A high percentage of energy is converted to local high-shear action in contrast to propellor or disc type mixers where a large proportion of energy is expended in movement of a large volume of material in the mixing vessel. Non-foaming. No air present. Product receives intense shear without foam. Process flexibility. Material can be run through once or recirculated. Units can be used in series or parallel. Retention time can be varied by governing the size of outlet opening or feed rate. Acts as pump. Mixer generally creates sufficient pressure to move material to next process unit.
Eppenbach IO” Pipeline Homogenizer with inlet flange removed. Model Sizes
Motor hP
2” 3”
%-1
4”
5” 6”
10”
2-5 5-10 10-20 15-25 30-60
Rotor rpm
Capucity in gp171 (2)
7000(’) 3600 3600 3600 3600 1750
30 70 150 2 00 250
1200
1-Belt-driven. Other models also available with belt-driven rotors for higher rotor speeds. 2-For comparative purposes only. Figures show approximate gpm of water pumped by unit against a 10 ft. head. Actual mixing volume for any unit may range from 50 to 200% of figures given. L e f t : Eppenbach IO” Pip e 1in e H omogenizer. N o t e simplicity o f design f o r easy maintenance.
Specifications Operating pressures. Std. - 100 psi. Units for 300 psig have been supplied. Seals. Liquid-flushed double mechanical type. Metals. As required. A standard metal for rotor and stator is 17-4 precipitation hardened stainless steel with other contact metals of 316 S.S. Motors. Standard-1 10 or 220V single phase or 220/440V 3 ph, 60c. Other motors on request. Mounting. Portable or stationary - in any position from horizontal to vertical.
Rental units Eppenbach Pipeline Homogenizers, in sizes up to 5”, can be rented for lab or pilot-plant operation to determine proper sizes, speed, etc.
G/FFORPHOO~ GO.
STATOR L
Dept. IEC 7, Eppenbach Division, Hudson, N. Y . Eppenbach colloid mills, homogenizers, homogenizer-mixers . . . f o r laboratory, pilot plant and large-scale production. Circle NO. 27 on Readers’ Service Card
VOL. 5 4
NO. 7 J U L Y
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.A Unit Operation
...accomplished more efficient/y with Pittsburgh Activated Carbor.. One of the redly unique advantages of a continuous column adsorption system, utilizingPittsburgh Granular Carbons, is that it functions as an engineered unit operation. Pittsburgh Granular Carbon in a column system is one continuous operation that provides madnum adsorption efficiency and can be added to your present production system with relative ease. Batch-type slurry tanka,filter pand intmnedia@ handling equipment, with their inherent higb cost mnintennneliminated.
PittaburghActivated Carbon in a column sen- r m t a b a cleaner operation, too, with no dust or slurry
..
problems. and, more important, you realize greater product yield, utilize lesa carbon, and, in turn, signifid y reduce adsorption oosts. If your adsorption pmcess involves decolorization, purification, deodorizationor catalysis,investigate Pittaburgh Granular Activated Carbon. Put theseadvantages to work in your pmcessingoperationsto help you produca an even better product. . .at lower cost. ..e19
Write For Free Brochure This brochure illustrates basic design techniques for both liquid and vapor phase. continuous column adsorption systems. Please write for your free copy there’s no obligation.
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CARBON DIVISION
E_I”J , C H E M I C A L al
GRANT BUILDING
CO.
PITTSBURGH 19. PA.
A Subsidiary of PITTSBURGH COKE I CHEMICAL CO.
clmo na. 88 om n e m w senice card 12
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
I&EC R E P O R T S operations for NASA’s Saturn project depends in part on Flodyne valves. Now the company is offering some of its valve designs to industry. One of these valves has already appeared in I&EC’I New Products (May 1962, p. 65). Flodyne has developed valves to handle liquid oxygen, nitrogen, and hydrogen. Others are designed for liquid helium a t temperatures close to absolute zero or helium gas a t pressures up to 6000 p.s.i. The valve design, evolved from needs of the rocket and missile programs, features compactness, fast operation, and ability to handle a wide variety of fluids-from corrosives to cryogenics. I t withstands shock and vibration and has high reliability. Forces exerted on the valve are balanced so that only 1Oyoof the force is applied to the control system. In a throttling valve this gives a wide range of very sensitive control and allows use of smaller actuators. At higher pressures and in large valves reduction of the force exerted on the control system becomes even more important. Rocket requirements led to a valve with negligible pressure drop, low operating torque, and a balanced seat design that gives a tight seal over a great many valve cycles. Long service life results from the high precision of mating parts. One of the big jobs now, so far as Flodyne is concerned, is to convince engineers and management that it’s worth while to buy a better valve for a higher price, and that it may cost less in the long run. A big selling point is reduced maintenance. Some Flodyne valves have doubled the usual time between servicing removals in continuous outdoor operation. Another feature that could mean considerable savings in designing complete new piping systems is the low turbulence and small friction loss in these valves. I n the usual system, much of the pressure loss is in the valves. Piping is often
W I T H T H E A D D I T I O N OF
L O W COST, M O R E EFFECTIVE, D I S P E R S A N T S By adding only .05% to 3.0% of Marasperse (based o n the weight of solids), a viscous pasty mass becomes an easy-to-handle freeflowing liquid. The action of Marasperse prevents, and reverts, the flocculation of insoluble particles in water suspension. Only the state of the mass is changed. T h e volume is unaffected because the Marasperse is taken into solution by the available water. T h e versatility of Marasperse dispersants is best described by the variety of applications in use, such as oil well drilling muds, gypsum slurries, ceramic slips, pesticides, dyestuffs, industrial cleaners, concrete, pigment, carbon black and clay dispersions, ore flotations, and many others. Marasperses are water-soluble, non-hygroscopic, non-fermenting, free-flowing powders. For additional information use the handy coupon.
MARATHON A D i v i s l o n of A m e r i c a n C a n C o m p a n y C H E M I C A L S A L E S DEPARTMENT
*Registered U. S. trademark
MENASHA.
WISCONSIN
- - * - - - - - - - - - - - _ - - - c -
MARATHON A D i v i s i o n o f A m e r i c a n C a n Co. M E N A S H A , WIS. C H E M I C A L S A L E S DEPT. Please send Information File No. 1-72 m, Samples 0 of MARASPERSE for use in ~
NAME TITLE COMPANY ADDRESS
~
~
.___ ~
.._________________________I____
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(Continued on page 74)
Please affach fo your company lefferhead. Circle No. 32 on Readers’ Service Card
VOL. 54
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NO. 7 J U L Y 1 9 6 2
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GRINDING AND PULVERIZING
I&EC REPORTS
N o matter what your grinding problem-coarse or fine grindball, pebble or autogenous-Hardinge has a mill for the job.
oversized to compensate. \7al\m with less pressure drop would mean smaller pipes, as well as loiter pumping loads. Flodyne valves are already finding a place in industry. One of the first customers is Linde, using them on tank trucks and rail cars transporting liquefied gases.
C A S C A D E @ MILLS
A continuous mill using t h e autogenous grinding principle-large pieces of material grinding t h e smaller ones. Shape of t h e mill causes maximum “free fall” a n d impact. Feed i s divided into coarse and fine components and re-combined in proper proportion for best grinding.
~~~
CASCADED MILLS
R O D MILLS
Steel rods are employed as grinding media. Ideal .for producing minimum oversize in open circuit grinding. Conical heads prevent “choking” of the charge at t h e ends, and align the rods. Available with either end, or center, peripheral discharge, as well as trunnion overflow.
ROD MILLS
DISC-ROLL MILLS
A roller-mill with rotating grinding table and spring-loaded or pneumatically-loaded rolls for complete flexibility of operation. The Gyrotors Classifier, combined with the Disc-Roll Mill, provides a highly-efficient dry-grinding device, idea for relatively soft minerals. PEBBLE M I L L S
For a fine product in open circuit without t h e use of classifiers. For mixing and grinding t o secure a smooth texture or plastic product. Often used as an autogenous grinding mill.
DISC-ROLL MILLS
C O N I C A L MILLS8
T h e shape of t h e Hardinge Conical Mill causes a rapid circulating and classifying action within the drum, which increases the capacity for power expended over other types. The range of grinding is large, due t o segregation of media and material within t h e mill.
PEBBLE MILLS
T R I C O N E * MILLS
Built on t h e same principle as the Conical Mill, the Tricone Mill offers greater grinding volume for a given amount of floor space. Extremely efficient. Ideal for large tonnages. Sizes u p t o 12 f t . diameter. CONICAL A N D TRICONE* MILLS
* Trademark
Write for Bulletin 17-(2-12. NEW YORK TORONTO CHICAGO SAN FRANCISCO HOUSTON LAKELAND BIRMINGHAM HlBBlNG
C i r c l e No. 20 on Readers’ Service Card
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
UNDERGRADUATES DO RESEARCH Can education really better meet the growing needs for technicaliy trained personnel? Strong efforts are under way to find the answer. Case Institute of Technology is investigating various proposals for improving the qualit)- and quantity of its graduates. Not particularly unusual is the practice ofgivingadvanced placement to entering freshmen who qualify on the basis of a series of rest results. Perhaps less common is the Case approach which introduces a research program in the undergraduate curriculum-sometimes even at the freshman level. This Summer at Case, 42 undergraduates in engineering, chemistry, and mathematics are lvorking fulltime in a 10-week research program financed by a $45,025 grant from the National Science Foundation. Most of the students are juniors, hut a few especial1)- talented sophomores are included. Undergraduate research is not limited to these 42 students, either. Others are already working with senior faculty members under Case’s regular research contracts. The problems that undergraduate research workers tackle are serious scientific and technical ones. Dr. R. C. Weast, director of the program, says they are narrower in scope, but I equal in depth to the problems which concern Case’s senior investigators. The program helps prepare the students for graduate school, and Case hopes it will speed completion of graduate work by giving them an earlier introduction to the methods, purposes, and techniques of research.
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