Flash driers

Polyethers such as monensin, lasalocid, salinomycin, and narasin are sold in many countries in crystalline or highly purified forms for incorporation into feeds or sustained-release bolus devices (see Controlled-RELEASE technology). There are also mycelial or biomass products, especially in the United States. The mycelial products are generally prepared by separation of the mycelium and then drying by azeotropic evaporation, fluid-bed driers, continuous tray driers, flash driers, and other types of commercial driers (163). In countries allowing biomass products, crystalline polyethers may be added to increase the potency of the product. 

Pregelatinized starches are formed when a dispersion of starch is dried on a heated roll or in a hot air (flash) drier. Added surfactants will aid in rewetting. The use of a pregelatinized starch simplifies the preparation of coating colors, but this practice is restricted due to higher cost and difficulties in obtaining a homogeneous product. 

Harvesting is continuous and under aseptic conditions, with medium recycle without re-sterilisation. Residual nutrients are monitored to ensure there is no build up (for example of phosphate). Hie cream (biomass) from flocculation and centrifugation is adjusted to normal pH (remember it was acidified for flocculation), then dried in an downstrsam air-lift flash drier. Forthis thecreamis fed into the venturi of the drier tube and is carried... 

In choosing the type of drier for drying the flue gas gypsum it was found that of all the cocurrent driers available, such as rapid driers, flash driers, or contact driers, the directly heated cocurrent rapid drier was the most suitable. Its design and mode of operation are described in Fig. 5. 

The resulting suspension of PCC is screened at about 50 pm and is either used as an aqueous suspension containing 20 to 50 % of solids, or de-watered using rotary vacuum filters, pressure filters or centrifuges. The resulting moist cake is dried in rotary, spray or flash driers. 

Sodium Bicarbonate. Many soda ash plants convert a portion of their production to sodium bicarbonate [144-55-8], NaHCO. Soda ash is typically dissolved, carbonated, and cooled to crystallize sodium bicarbonate. The mother Hquor is heated and recycled. The soHd bicarbonate is dried in flash or tray driers, screened, and separated into various particle size ranges. Bicarbonate markets include food, pharmaceuticals, catde feed, and fire extinguishers. U.S. demand was approximately 320,000 t in 1989 world demand was estimated at one million metric tons. 

The floated mica concentrate is dewatered. After dewatering (qv), the mica is either dried in a fluid-bed rotary drier, flash dried in a fluid energy mill, or sold "drip-dry" to other mica grinders. The dry mica is then ground and screened to a si2e gradation dictated by the customer. 

One centrifuge was powered by a hydraulic oil installation 2-3 m away. A leak of oil from a cooler was ignited, and the fire was spread by oil and product spillages and by plastic-covered cables. It destroyed the plastic seal between the centrifuge and its exit chute. There was an explosion in the chute and a flash fire in the drier to which it led. The centrifuge exit valve was closed, but the aluminum valve actuator was destroyed. Fortunately, the exit valve did not leak, or several tons of solvent would have been added to the fire. Aluminum is not a suitable material of construction for equipment that may be exposed to fire. 

Boiled linseed oil is a misnomer, since the oil does not boil. Small amts of driers (oxides of Mn, Pb or Co, or their naphthe-nates, resinates or linoleates) are added to hot linseed oil to accelerate drying. The boiled oil becomes thicker and darker. It is combustible, with a flash p of 403°F and an autoignition temp of 650°F (Ref 4)... 

Figure 5 Phillips Particle-forming process a) catalyst hopper b) double loop reactor c) flash tank d) purge drier e) powder-fed extruder f) impeller g) sedimentation leg.

A continuous process for polymerization of nylon 6,6 in which a fluidized bed solid state polymerization reactor is used as the high polymerizer is represented schematically in Figure 3 (26). In this process the low molecular weight polymer is produced in a filled pipe reactor located just upstream of the spray drier. The liquid product of this step is then sprayed into a hot inert gas atmosphere where the water is flashed off and a fine powder is produced. This powder is fed into an opposed-flow, fluidized bed reactor at 200 °C where the high molecular weight polymer powder is generated at temperatures well below the 255 °C melting point of nylon 6,6. The powder is then melted in the extruder and converted into fiber or chip. 

PAINT DRIER (1338-02-9) Forms explosive mixture with air (flash point 100°F/38°C). Violent reaction with strong oxidizers, strong acids. Mixtures with 1,3-di(5-tetrazoyl)triazene are heat- and friction-sensitive explosives. Increases the sensitivity of explosive hydrazinium perchlorate. Incompatible with acetylene, ammonium nitrate, mercurous chloride, picric acid, silver nitrate. 

Features Optimizes drier perfonnance no ozone-depleting substances Properties Liq. n-butanol odor dens. 0.95 mg/m dens. 7.9 Ib/gal flash pt. (CC) 36 C min. VOC 492 g/l... 

Uses Drier for waterborne oxidatively drying alkyd resin paints, esp. externally emulsified alkyd resin emulsions Features Lead-free, barium-free nonylphenol ethoxylate-ffee Properties Violet liq. water-emulsifiable dens. -1.09 g/cm (20 C) dynamic vise. 150-1000 mPa s flash pt. = 66 C 5% Co, 0.22% Li, 7.5% Zr Use Level 1-3% (on solid resin)... 

Uses Drier, chelating catalyst in modified polyurethanes and alkyds, clear and brightly pigmented oil- or alkyd-modified polyurethanes, in conventional alkyds which tend to discolor, traffic paints, anticorrosive primers, marine topcoats, wood furniture coatings Features Replaces cobalt drier Properties Sp.gr. 0.85 dens. 7.1 Ib/gal flash pt. 27 C Dapro 7007 [Elementis Spec. U.S.]... 

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