EQUIPMENT
GOES ON IN A HURRY. Wyandotte's urethane foam goes onto rough or smooth surfaces, dries t o the touch in five minutes. This tank took 3 0 man-hours t o coat
Foam Produces Improved Insulation Wyandotte's urethane foam containing fluorinated hydrocarbon gas cuts heat losses, saves labor w
VAXDOTTE CHEMICALS has
devel
oped an improved method for spraying rigid urethane foams based on polyethers. Potential uses: insulation for process equipment, corrosion preven tive. Wyandotte uses polyethers in stead of polyesters because, the com pany says, they are cheaper and have better aging stability. An unusual feature: The blowing agent for these foams is a fluorinated hydrocarbon—Freon 11, Genetron 11, Ucon 11, or Isotron 1 1 . Normally, carbon dioxide generated through chemical reaction produces the foam. As the liquid fluorinated hydrocarbon vaporizes in the new formulation, it forms the plastic's cellular structure. Furthermore, most of it remains in the foam, thus boosting heat-insulating properties. Thermal conductivity of the gas-containing foam is about 0.14 for a 2-lb.-per-cu.-ft. foam—compared to more than 0.2 for conventional insu lation such as glass fibers, cork, or ex panded polystyrene. > Developed with DeVilbiss. Wy andotte worked out the new system with DeVilbiss Co., a maker of spray equipment. T h e spray gun was spe cially designed; the auxiliary pressure units are the types normally used to 56
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spray paint. The DeVilbiss equipment is compact, easy to move around, and relatively low-cost, Wyandotte adds. The foam itself can be sprayed on both smooth and irregular surfaces. In most cases, the surface does not have to be specially treated beforehand. The foam is self-adhering and is dry to the touch five minutes after it is ap plied. It produces a continuous coat ing resistant to weathering a n d chemi cal attack, Wyandotte says. And it can b e readily painted with conven tional paints. Foam goes on at 10 to 20 board-feet a minute. In single-pass operation, the foam rises to about l1 L» in. Repeated passes produce thicker coatings. > Has Been Used. Wyandotte at its headquarters plant in Michigan has already insulated several large pieces of process equipment with the new foam. One is a cone-shaped brine tank, 35 ft. high and 2 5 ft. in maximum diameter. Brine in t h e tank is kept at 6 8 ° F . Before it was insulated, it h a d a great deal of water condensed on its outer surface during hot, humid weather. This moisture accelerated corrosion. With the new foam insulation, there is no condensation, Wyandotte says. In some cases, you can save up to
75'< with the new foam, says Wyan dotte. Main source of savings: greatly reduced labor costs. With conven tional block insulation, four men would have taken two weeks to complete t h e insulating job on t h e cone-shaped tank. Spraying took only 30 man-hours. Wyandotte makes two of the rawmaterials—Pluracol T P 4 4 0 and Quadrol —used in the new foam. Pluracol T P 440 is o n e of a series of polyoxyprop^f cue derivatives of trimethylolpropane. Quadrol serves as a catalyst and crosslinking agent. Chemically, it is Λ7, N, Ν',Ν'-tctrakis ( 2-hydroxypropyl ) ethylenediamine. In t h e spray gun, two liquid input streams combine into a single stream. One of these two inputs is a solution of Quadrol and liquid fluorinated hydro carbon. The second is the prepolymer—a mixture of tolylene diisocyanate a n d Pluracol T P 4 4 0 . Air at about 90 p.s.i. atomizes the output stream, which discharges at 3 to 5 lb. of liquids per min. The prepolymer will b e made by cus tom formulators—not b y Wyandotte. T h e spray equipment will be sold by DeVilbiss. • Problems Tackled. In develop ing a sprayable urethane formulation, Wyandotte faced several major prob lems. It needed a formula that: • Has low enough viscosity that it can be sprayed at moderate pressures. • Solidifies rapidly, so that it can be sprayed on vertical surfaces without sagging or dripping. • Traps the fluorinated gas in t h e foam.
hydrocarbon
• Is relatively insensitive to small variations in proportions of the various ingredients. • Resists heat and corrosion. Wyandotte says the new formula largely meets these requirements. T h e finished foam can withstand tempera tures as high as 2 2 0 ° F . Research is going ahead on improved formulations to permit even higher service tempera tures. Wyandotte chemists are also working on ways to improve the fire retardant properties of the foam. Wyandotte expects increasing use of these materials in plant maintenance a n d new construction. Sprayable ure thane foams might insulate everything from pipes a n d tanks t o cold storage rooms a n d Quonset huts.
EQUIPMENT
Briefs · · . • L a b o r a t o r y h o m o g e n i z e r to d i s p e r s e o r e m u l s i f y l i g h t - t o - v i s c o u s m a t e r i a l s is n o w available from Cornell Machine, X e w York C i t y . Of s t a i n l e s s s t e e l , t h e in lit o p e r a t e s at a p r e s s u r e r a n g e f r o m 3 0 in. of m e r c u r y ( v a c u u m ) t o a t m o s p h e r i c , t h e c o m p a n y s a y s . It is 12 in. w i d e , 2 1 in. h i g h , and 3 8 in. l o n g . Ε Ί • Mobile vacuum system has been de s i g n e d b y F i s h e r Scientific, P i t t s b u r g h , P a . T h e u n i t m a i n t a i n s p r e s s u r e s from 2 5 0 d o w n t o 0 . 5 m m . ( d e p e n d i n g on t h e l o a d ) a n d h o l d s t h e m w i t h i n dz().2 m m . , F i s h e r says. A 1 A h p . t w o - s t a g e v a c u u m p u m p operates the system. Ε 2 • G r a d u a t e d c y l i n d e r s m a d e of p o l y p r o p y l e n e h a v e b e e n a d d e d to its line b y N a l g e , R o c h e s t e r , Ν . Υ. Volumes a r e easily r e a d , N a l g e s a y s , b e c a u s e w a t e r in p o l y p r o p y l e n e h a s a l m o s t no meniscus. T h e cylinders are available in six sizes from 2 5 to 1 0 0 0 m l . Ε3 • Strengthened glassware designed for s t u d e n t u s e c o m e s from C o r n i n g C l a s s W o r k s , C o r n i n g , Ν . Υ. Made f r o m b o r o s i l i c a t e glass, t h e i t e m s resist h e a t , shock, a n d chemical attack, ac-
c o r d i n g to C o m i n g . They include a volumetric pipet, both plain and l a b e l e d reagent bottles, a thistle t u b e funnel, and b u r e t s w i t h straight-bore stopcocks. Ε4 • Electrically heated l a b o r a t o r y oven for u s e with flammable l i q u i d s , g a s e s , a n d v o l a t i l e s o l i d s is n o w b e i n g m a d e hy D e s p a t c h O v e n , M i n n e a p o l i s , M i n n . D e s i g n e d to h e e x p l o s i o n - p r o o f , it is a v a i l a b l e in t e m p e r a t u r e r a n g e s from a m b i e n t to 5 0 0 ° , 6 5 0 \ a n d 8 5 0 ° F., the c o m p a n y says. Ε5 • B e n c h o v e n for use at from 1 2 5 ° to 1000° F . comes from A m e r i c a n Instru ment, Silver Spring, M d . E l e c t r i c re s i s t a n c e h e a t e r s l o c a t e d in all six w a l l s g i v e a t e m p e r a t u r e u n i f o r m i t y of =b4°
ι I I | •
I
at 1 0 0 0 F . , t h e c o m p a n y says. The o v e n is 3 4 b y 3 3 in. a n d is said t o g o from r o o m t e m p e r a t u r e to 1 0 0 0 ° F . in 3 1 .» h o u r s . Ε 6 • Mechanical convection ovens come f r o m B l u e M E l e c t r i c , B l u e I s l a n d , 111. Of steel a n d s t a i n l e s s steel, t h e o v e n s h a v e a t e m p e r a t u r e r a n g e from 150 to 1200° F . a n d can be controlled w i t h i n -±2C F . , t h e c o m p a n y s a y s . T h e u n i t s ire available» in f o u r sizes w i t h c a p a c i ties f r o m 1 t o 11 c u . ft. Ε 7
I I I I {
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t Tiniest GLC Yet H a n d - s i z e d gas-liquid chromatograph w i t h s e p a r a t i o n efficiency e q u i v a l e n t to 1 5 , 0 0 0 t h e o r e t i c a l p l a t e s s e p a r a t e s 10 c o m p o n e n t s to n - p e n t a n e in 2 m in., c a n m a k e s o m e s e p a r a t i o n s in j u s t a few seconds. D e s i g n e d b y Shell D e velopment's instrumentation depart m e n t , E m e r y v i l l e , Calif., t h e u n i t s h o w n is c o m p l e t e e x c e p t for r e c o r d e r a n d c a r rier gas. Key t o small size: a new c o l u m n design w h i c h gives high reso l u t i o n w i t h h i g h s p e e d . Shell s a y s t h e t e c h n i q u e c a n b e a p p l i e d to p r o c e s s gas chromatography.
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