Feeds drying

Ma.nufa.cture. The preparation of sulfuryl chloride is carried out by feeding dry sulfur dioxide and chlorine into a water-cooled glass-lined steel vessel containing a catalyst, eg, activated charcoal. Alternatively, chlorine is passed into Hquefted sulfur dioxide at ca 0°C in the presence of a dissolved catalyst, eg, camphor, a terpene hydrocarbon, an ether, or an ester. The sulfuryl chloride is purified by distillation the commercial product is typically 99 wt % pure, as measured by ASTM distillation method D850. 

The overriding consideration in the selection of drying equipment is the nature and concentration of the feed. Drying is an energy-intensive process, and the removal of liquid by thermal drying will be more costly than by mechanical separation techniques. 

Table 100 CO conversion rates as a function of steam/gas (S/G) ratio under high temperature shift conditions. Feed (dry basis) 10% CO, 10%CO2, 50% H2, 30% N2. WHSV = 42 h l. 33 mg of catalyst employed469...

When feeding dry food, provide just enough food so that most of it remains on the water surface. 

The material comes off as flakes 1-3 mm or less thick. They are broken up to standard size of about g in. square. That process makes fines that are recycled to the dryer feed. Drying times fall in the range of 3-12 sec. Many laboratory investigations have been made of drying rates and heat transfer coefficients, but it appears that the only satisfactory basis for sizing plant equipment is pilot plant data obtained with a drum of a foot or more in diameter. Usually plant performance is superior to that of pilot plant units because of steadier long time operation. 

Formation of spray in small drops (i.e. 30 microns, with a narrow size distribution) using a rotary disc or nozzle, to enhance the product-air interface. The preparation of the feed (dry matter content, composition, temperature, mixing) must facilitate pumping and spraying with minimal modification (partition of constituents, droplet coalescence in emulsions). 

Feeding supplement fats at concentrations greater than 2-3% of feed dry matter. Degree of fatty acid solubility, with medium-chain (12- to 14-carbon) and unsaturated (vegetable oils, fish oils) being most inhibitory. 

Ruminants are equal to or superior to nonruminants in their ability to digest saturated fatty acids, but unsaturated fatty acids fed conventionally have lower digestibility due to rumen biohydrogenation. Unsaturated fatty acids, fed in protected form, are digested equally in ruminants or nonruminants. Moderate levels of added fat (up to 3% of feed dry matter) are 85% truly digestible (52). 

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