Drying atmospheric roller

Conventional processing equipment (mixers, granulators, roller compactors, drying equipment, and mills) can be used to produce effervescent preparations if the influence of atmospheric moisture is considered. As a rule, tablet presses have to be adapted to handle effervescent products, except for tablets with a sufficient proportion of a self-lubricating substance, such as acetylsalicylic acid. 

Waste Products.—Offal and tankage are generally handled in rotary steam jacketed dryers, in small quantities. Large plants use the tubular type, and the direct-heated dryer, and the concentrated stock coming from the tank-water evaporators is either added to the wet tankage, or dried separately on atmospheric drum dryers, so-called stock rollers. Garbage which has first been degreased is usually handled in a direct heated dryer. 

Chemical retting consists of softening the tissues by boiling with dilute oxalic acid or alkali either at atmospheric or higher pressure. After treatment, the soluble bodies formed by the degradation of the less-resistant tissues are washed away. The process is considerably quicker than those relying upon natural fermentation. After retting, by whichever means, the residual tissues are passed between squeeze rollers to remove the excess liquor, and are then well washed in fresh water and dried. 

These single-pack protective coatings, based on chlorinated rubber, are fast drying and give very good water, chemical and corrosion resistance. They are suitable for coating steel and concrete surfaces and are recommended for applications subject to chemically laden atmospheres or in a coastal environment and can be applied by spray, roller or brush. Typical uses include bridges, chemical plants, marine structures, ships and structural steelwork. 

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