REPORTS I/EC
Westinghouse's new a l l o y , Nivco (right), damps d o w n within seconds when comp a r e d to carbon steel tuning fork
Present-day blade materials, such as 12% chrome steel, have excellent over-all properties up to about 1050° F. Above that, chrome steel must be used at lower stress levels. Nivco, however, has properties at 1200° F. similar to the 12% chrome steel at 900° F. Its 100-hour rupture life is around 50,000 p.s.i. at 1200° F . ; damping capacity is 10 times greater than similar "super alloys" at vibrational tensile strengths between 5000 and 10,000 p.s.i. Endurance limit, again at 1200° F., is about 45,000 p.s.i. These properties, say Westinghouse steam engineers, make Nivco a "natural" for turbine applications. It should prove a major forward step, not only in turbine design, but in metallurgical research as well, since the new alloy resists turbine vibration simply because its magnetic structure, predicted by predesigning, dictates it cannot vibrate. The new alloy is now a pilot plant material, made by melting in a vacuum furnace under an inert atmosphere of argon gas. After melting, it is treated and forged at 2000° F. The metal should solve turbine problems for the next few years, explain company officials. But, Westinghouse researchers are taking the long-term approach. Already, work has started on a new, and hopefully better, series of alloys, not only for turbine applications but other high temperature uses as well. W.S.F.
Equipment Design Trends ment gives three times more d a m p i n g than c h r o m i u m steel — t o d a y ' s accepted product. H e n c e , N i v c o w a s m a d e by precipitation-hardening the CoN i base a l l o y a n d a d d i n g s o m e minor elements to i m p r o v e properties. Result: A n a l l o y specially designed for steam turbines of t o m o r r o w .
Today's turbine blades usually rotate around 3600 revolutions per minute. Temperatures exceed 1000° F. But, the trend has been to higher and higher operating
temperatures—near 350° back in 1900; 1050° today—an average yearly rise of 13° F. Soon, temperatures will hit 1200° F. Under these conditions, a host of forces will act, causing extensive vibration and eventual reduction of operating life and efficiency. To reduce the amplitude of vibration, the blades must be damped— either artificially or inherently. Simultaneously, the metal must retain strength and corrosion resistance demanded of all turbine blades which operate at high temperatures.
Research programs are expected to have greater influence on process equipment design
CHANGES
in
chemical
and
pe-
troleum processing equipment— whether in pumps, cooling towers, trays for distilling columns, or equipment for other unit operations and processes—appeared in the past largely as a result of operating exVOL. 48, NO. 11
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Pattern for PROGRESS Each m o n t h , l&EC w i l l s h o w h o w articles published in earlier l&EC v o l u m e s helped set future industrial patterns. Last m o n t h , the Cottrell precipitator set the pattern in the 1 9 1 1 l&EC. This m o n t h , w e look at the 1 9 1 2 l&EC a n d h o w t w o m e n called industry's attention to the solvent properties of carbon tetrachloride.
In the 1912 l&EC, Charles Baskerville and H. S. Riederer set forth the requirement of a solvent of value to industry in a paper entitled " T h e Chlorides of Carbon as Solvents, I : Carbon Tetrachloride." The authors' suggestions were supported by data collected in many experiments on solubility determinations of asphalts, refined bitumens, rubber, gums, shellacs, oils, and waxes. Here are some of the developments (relating to this original paper) which took place in later years.
I HE industrial use of carbon tetrachloride as a solvent steadily increased in the period following 1912, but it was really the dry cleaning industry that began to use carbon tetrachloride as a solvent on a large scale. In 1935, 6 5 % of the total production or about 19,000 tons
were used. Total initial carbon tetrachloride production in this country was about 1 ton, by the Warner Chemical Co., in 1902. But fate in the form of modern technical development has a way of changing things. Today, only about 7 % (9000 tons) of production is used for dry cleaning. Perchlorethylene has replaced it. Stabilized perchlorethylene is made to order for units where heat is present and where efficient reclaiming units permit greater solvent coverage per pound of clothing. This reduces solvent costs. The constant decline in dry cleaning use of carbon tetrachloride can be expected to continue until existing equipment is obsolete. By 1960, it is doubtful if more than 2 % of the annual production of carbon tetrachloride will be used for dry cleaning. At the same time, the demand for carbon tetrachloride has greatly
increased over the years because of totally new applications of its solvent powers in new chemical products and processes. About 76,000 tons, representing over 57% of the 1955 production, were used in industrial propellants and refrigerants. By 1960, the chlorofluorocarbon refrigerants are expected to consume some 68 to 70% of the total annual production. The grain· fumigant field is expected to use considerably more carbon tetrachloride than in the past. By 1960, approximately 10 to 12% of the annual production will go into this end use. One of the most important factors to stimulate this increase is the Department of Agriculture's recent action to clean up the "in transit" grains and to protect the government-stored grains by constant turning and heavy fumigation. Carbon tetrachloride type fumigants will be used. There is no doubt that this 1912 l&EC paper was responsible for increased attention to a chemical which today has become very important. As the current picture is reviewed today, the very essence of technological change prevails, with newer, safer, and more efficient chemicals replacing this solvent in its original applications. Next month— the 7973 l&EC calls attention to the commercial utilization of nelsonite.
perience and needs. Need will probably always be the prime motive for design improvements, but future trends are likely to be based on cost factors such as down time, maintenance, operating, and accounting, labor and parts inventory, water availability in the case of cooling equipment, fundamental research into whys of operating efficiency. A survey of engineers associated with all phases of process equipment—design, manufacture, selling —indicates that every item is receiving the attention of engineering research in an effort to improve performance in some way. It is a • All electric p a n e l , permitting a single o p e r a t o r to control a refinery, is t y p i c a l of t o d a y ' s trend t o w a r d compact and centralized control of process equipment VOL. 48, NO. 11
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NOVEMBER" 1956
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Thirty Million B.T.U. CAPACITY
I/ECREPORTS
complex picture; changes in equip ment and the thinking behind these changes require constant review. In this short space only some significant changes in various classes can be noted. Automation may influence equip ment design to an extent undreamed of today. Automatic equipment will reduce direct operating labor cost but raise maintenance labor cost. By incorporating automatic control equipment with maximum relia bility, the designer can make or break the economic performance of process equipment. A u t o m a t i o n and Electronics Are Inseparable
Electronic controls have several advantages beside compactness for large scale operations: • • •
Cooling in Chemical Processes with Precise Control off T e m p e r a t u r e T h e N I A G A R A Aero H E A T E X C H A N G E R cools liquids and gases by evaporative cooling with atmo spheric air, removing the heat at the rate of input, con trolling temperature precisely. You save 9 5 % of cost of cooling water; you make great savings in pumping, piping, power; quickly recover your installation cost. You can cool and hold accurately the temperature of all fluids, air and gases, water, oils, solutions, chemical intermediates, coolants for mechanical, electrical and thermal processes. You obtain closed system cooling free from dirt. You solve all the problems of water availability, quality or temperature. In C H E M I C A L P R O C E S S E S this is successfully used in cooling liquids and gases, chemical reactions, condensing distillations and reflux cooling. W r i t e for complete information; ask for Bulletins 120 and 124. Address Dept. E.C.
NIAGARA
BLOWER
4 0 5 Lexington A v e .
District
Engineers
in Principal
COMPANY
N e w York 17, Ν . Υ.
Cities of United States and
For further information, circle number 18 A on Readers' Service Card, page 117 A
18 A
INDUSTRIAL AND ENGINEERING CHEMISTRY
Canada
More precise control Lower capital investment Less maintenance cost
Electrical communication gets the nod now as the result of develop ment of equipment permitting un restricted location of controls and dis tance to units in the system, and adaptability to a wide range of process variables. Data logging has gotten out of the hands of operators, who are usually too busy during pe riods of emergency to log data. But data logging also shows its impor tance in normal operation, and systems of automatic data logging are in use in the control rooms of newer chemical plants and re fineries. Higher Temperatures
Among nondirect cost considera tions in design, several future trends stand out. One cited by several chemical engineers is increasing use of higher temperatures. This trend is made possible through results of high temperature metallurgy and refractory research. In this field, the process industries will benefit from the by-products of the government rocket research program. Advances in metallurgy and in lubrication will bring changes in reciprocating and rotating process equipment. Results of metallurgical research will allow greater physical strength and corrosion resistance over a wide range of temperatures. Syn-
I/ECREPORTS
FA
thetic lubricants will permit operat ing wearing parts also over wider temperature ranges, but most signifi cantly at higher temperatures. These advances will result in higher speed, more efficient, smaller, lighter, and less expensive equipment.
®
Pumps a n d Fractionating Equipment Are Getting Most Attention
FILLS THE GAP IN UREA GLUES stronger
bonds . .. increased resistance
economically
craze ...
achieved
HC
CH
F L U S H
II II HC
D O O R
C-CHiOH Ο
Q O Furfuryl Alcohol modified urea resins form gap-filling glues of e x c e p t i o n a l s t r e n g t h . S u c h a d h e s i v e s a r e flexible, r e s i s t cracking a n d deterioration u p o n aging. T h e y reduce s h r i n k a g e a n d assure a n e n d u r i n g bond u n d e r m a n y conditions of pressure, t e m p e r a t u r e , a n d glue line thickness. MANY OTHER USES. Versatile F A also dissolves nitrocellulose, d y e s a n d m a n y resins; a c t s as a w e t t a n t a n d reactive solvent for resin-bonded abrasives; a n d forms resins which cure a t r o o m t e m p e r a t u r e t o acid a n d alkali resistant p r o d u c t s . If y o u r glue supplier c a n n o t furnish this p a t e n t e d adhesive, write t o u s for n a m e s of t h e m a n u f a c t u r e r s .
Write for your copy of
TECHNICAL
BULLETIN 2 0 5
"General Information, Physical Data, Chemistry a n d Uses o f F u r f u r y l A l c o h o l "
The Quaker Oafs (pmparyy
337B The Merchandise Mart, Chicago 5 4 , Illinois Room 537B, 120 W a l l Street, N e w York 5 , N e w York Room 437B, Main P. O. Box 4 3 7 6 , Portland 8 , Oregon In t h e United Kingdom: Imperial Chemical Industries, Ltd., Billingham, England In Europe: Quaker Oats-Graanproducfen N. V., Rotterdam, The Netherlands; Quaker Oats (France) S. Α., 3, Rue Pillet-Will, Paris IX, France; A / S " O t a , " Copenhagen, S. Denmark In Australia: Swift & Company, Pty., Ltd., Sydney I n Japan: F. Kanematsu & Company, Ltd., Tokyo
For further information, circle number 20 A on Readers' Service Card, page 117 A 20 A
I N D U S T R I A L A N D ENGINEERING
CHEMISTRY
We have mentioned editorially the work of the ASA committee whose objective is standardizing pumps dimensions and desirable features (such as back or front opening). This committee is mov ing slowly to avoid hasty conclusions based entirely on technical data. If this seems a slightly heretical ap proach, look at one engineer's slant: Technical data alone are not enough to make complete standards; main tenance labor costs, for instance, are difficult to evaluate—to check some pumps, a pipe fitter and an elec trician are needed besides a me chanic. Changes in pumps and their op eration which have already taken place include a wide range of dif ferent impellers now available for many services and experimental use of very high speeds to get high heads and volumes. Impellers which will handle entrained air and prevent suction loss are available as the result of importing certain Europen patents. To date, higher heads from higher speeds remain experimental and accepted com mercially to only a very limited extent. In spite of the state of flux in pump standards, some manufac turers have gone ahead and stand ardized on pump dimensions and features. API has issued tentative pump specifications (610). Research in fractionation has been challenging the conventional bubble cap tray for some years now. Celanese has been making great use of the perforated plate [I&EC, 44, 2238 (1952)], Shell's Turbo-grid tray was described in this section of I&EC four years ago (I&EC, Sep tember 1952, page 13A). Other large refiners have developed their own trays—Esso's Jet-Tray which has covered perforations directing the vapor horizontally, Socony's Uniflux, an interlocked channel-type tray, Pan American's Panapak, a
THIS IS THE STORY of three men
