ΕΝ VER
I
THICKENERS
EQUIPMENT
Fight Corrosion With Clad Ti Chicago Bridge & Iron finds that its titanium-clad vessels can withstand stiff abuse • . . f o r a l l wetter a n d w a s t e t r e a t m e n t , w a s h i n g , thickening and clarification operations· #
New simplicity, new efficiency, long, trouble-free service. Simple, rugged, fully-enclosed gear mechanism. Gear sizes through 7 2 " dia. Spiral rakes or rakes to suit operation in tanks up to 150' d i a . Write for Bulletin No. T5-B6. Phone CHerry 4-4466
DENVER Adjustable Stroke DIAPHRAGM PUMPS
. . . f o r handling and metering thickened solids. Stroke can be adjusted while pump is oper ating. Capacity to 1000 g.p.m. Write for Bulletin P8-B12. See our catalog, pages 997-1004 i n CEC.
D Ε
V Ε
E Q U I P M E N T CO. BOX 5268, DENVER 17, COLORADO
MBQM WET-^frOUNP-AND-ŒN^TRIFUGALLY CLASSIFIED— TREATED A N D UNTREATED DRY GROUND A N D AIR FLOATED - BOTH R A Y M O N D A N D TUBE MILL PRODUCTS CRUSHED A N D SCREENED
92
C&EN
OCT.
12,
1959
I T ' S a complete success. That's the way Chicago Bridge & Iron, Chicago, 111., describes die titanium-clad vessel it built early this year for an undisclosed west coast petrochemical company. Calling it "the world's first titanium-clad pressure vessel of commercial size/' GB&I says the unit has stood up well after months of strenuous service. The vessel was designed for use at 150 p.s.i. at 500° R About 4 ft. in diameter by 12 ft. high, it is made from plates of 1 2 -in. mild steel clad with ·"· ,i4-in· and 7 , i4 -in. titanium, grade A40. The top and bottom hemispherical heads are welded from pressed segments, and the fittings and flanges are titanium lined. CB&I sees a promising future for titanium-clad equipment in the chemical, petroleum, paper, and other processing industries. With these units, the user gets the benefit of titanium's high corrosion resistance at much less cost than would be possible if they were made of solid titanium. Before building the large-scale titanium-clad vessel, CB&I constructed an, 18-ineh-high pilot unit which it tested for over a year. In particular, the company had to be sure that the welding technique used to join the individual clad plates would give good results. ί Problems Solved. CB&I says it has worked out methods to prevent the titanium from being contaminated by the steel backing during formation of the clad plate. Contamination could greatly reduce the corrosion resistance of the titanium. The company has also found ways to form the clad sheets in sizes comparable to those of conven tional corrosion-resistant metals. So far, the largest sheets formed have been δ ft. b y 7 ft. Declining to discuss details, CB&I says its cladding process involves use of a metallic powder that acts as a bonding agent. This powder is placed between the titanium sheet and the backing plate and is heated to a temI perature that will liquefy the powder.
Vacuum is applied betxveem the sheet and backing plate to make sure that a good seal is formed. CB&I's fabrication center for tita nium-clad equipment will b e in Birm ingham, Ala. The company says it is now set up to build titanium-clad equipment commercially.
More Analyzers Added Equipment makers a d d six more a n a l y t i c a l instruments to the growing list «ANALYTICAL, instruments continue to come thick a.nd fast from developers* labs. This w^ek, there are s i x more for users to choose from: • Process r-efractometer, from Mine Safety Appliances, Pittsburgh, Pa., for continuous m«asiiremeiit and control of organic and inorganic liqxiids. The unit compares the refractive index of a stream with a standard, is built in modules to f i t it for h i dust rial use. • Portable infrared analyzer, also from Mine Safety Appliances, is de signed for process streams or atmos phere control problems where you do not need extreme sensitivity or selec tivity. The Model 3O0 LI Β A weighs only 30 lb. a n d is more simply designed than MSA's other IR instruments. • Dissolvecd oxygen meter, from Hays Corp., Michigan City, Ind-, automati cally analyzes and continuously records dissolved oxygen in surface waters such as sewage a n d industrial plant effluents, rivers and sti-earns, and reservoirs. The unit is basec3 on Henry's Law—partial pressure of oxygen above a water sur face is proportional t o the amount of oxygen ir> trie water—and detects the oxygen by its paramagnetism. • Suppressed range oxygen analyzer, again from Hays Corp., also uses oxy gen's paramagnetism, gives concentra tion spans from 1 Vr t o 6'/£ when oxy gen content is 30% or less (20% to
metallic catalysts speed synthesis of NEOPENTYL GLYCOL POLYESTERS Report from Eastman research
direct polyesterification on commercial scale now practical derivatives noted for resistance to heat, water and sunlight Direct polyesterification reactions of neopentyl glycol with dibasic acids have been under intensive study at Eastman's Development Laboratories for more than a year. Results of this work show that the long reaction period normally associated with the preparation of neopentyl glycol polyesters may be shortened considerably through use of the proper metallic catalyst system. The study demonstrates, too, that the problems of side reactions, color formation and polyester cracking, which attend lengthy reaction periods at high temperatures, are minimized through shorter reaction times. A report on the nature of the catalyst evaluated and the procedures and techniques employed is available upon request. Interest in polyesters based on neopentyl glycol stems from the stability characteristics it possesses and, in turn, imparts to its derivatives. These stability characteristics are attributed to the compact, symmetrical molecular configuration of neopentyl glycol, and, in particular, to the presence of the two methyl groups on the central carbon atom. For example, when neopentyl glycol is condensed with a dibasic acid it results in an easy-processing plasticizer of moderate molecular weight that exhibits permanence properties equal or superior to those of polymeric plasticizers of higher molecular weights. Eastman offers such a product in its polymeric plasticizer NP-10. Certain hydroxy-terminated polyesters of neopentyl glycol show promise in the manufacture of both rigid and flexible polyurethane foams.
These foams feature better tensile properties and improved resistance to sunlight and heat. Unsaturated polyester resins made with neopentyl glycol can be formulated to meet an extended range of desirable mechanical requirements. The electrical properties of several of these suggest their use in insulating varnishes. Others, because of their hydrolytic stability, may be useful as water-soluble resins. Among other derivatives of neopentyl glycol that warrant investigation are unsaturated polyester resins for cross linking with styrène; monoesters through diester interchange with neopentyl glycol for hydraulic fluids; and diesters for lube oil additives and for synthesis of specialized lubricants. A copy of the technical data report describing this study as well as samples of neopentyl glycol may b e obtained through your Eastman Chemical sales office or from Eastman Chemical Products, Inc., Chemicals Division, Kingsport, Tennessee.
Jtj astman CHEMICAL PRODUCTS, INC. subsidiary of Eastman Kodak Company KINGSPORT, TENNESSEE
SALES OFFICES: Eostmon Chemical Products, Inc., Kingsport, Ten n. ; Atlanta; Chicago; Cincinnati; Cleveland; Detroit; F
