Equipment drying

Another concentration method involves passing an inert gas such as N2 or CO2 through the reaction medium (12). As the gas passes through, it becomes humidified and carries captured water with it. Most of the energy required for the gas humidification comes from the heat of reaction. An advantage is that expensive drying equipment is not needed. Also, the sulfuric acid mist formed in typical concentrators is minimized. Du Pont uses a similar process in its nitrobenzene production faciUty. 

There are 10 producers of calcium chloride solutions in the United States, three of these also make a dry product. Solution production is centered around Michigan (brines), California and Utah (brines), and Louisiana (by-product acid). The majority of dry calcium chloride is made in Michigan, lesser quantities in Louisiana, and minor quantities in California. Production involves removal of other chlorides (primarily magnesium) by precipitation and filtration followed by concentration of the calcium chloride solution, either for ultimate sale, or for feed for dry product. Commercial dry products vary by the amount of water removed and by the nature of the drying equipment used. Production and capacity figures for the United States are indicated in Table 2. 

Air Drying Equipment. Tunnel kiln dryers (70) are long furnaces comprised of several zones of different temperature, humidity, and air flow through which the ware travels on a moving car or belt. These kilns afford continuous processing. Periodic kiln cross-circulation dryers (70) are box furnaces in which ware is stacked on permanent racks or on a car that can be shuttled in and out of the furnace. Fans or jets are used to circulate heat uniformly through the ware. The process is not continuous, but production rates can be enhanced by shuttling multiple cars. 

The material on solids drying is divided into two subsections, Solids-Drying Fundamentals, and Sohds-Drying Equipment. In this introductory part some elementary definitions are given. In solids-gas contacting equipment, the solids bed can exist in any of the following four conditions. 

Since the standard insulation level (BIL) of a machine, equipment or a system is already defined, according to Tables 11,6. 14.1, 32.1(A), 13.2 and 13.3. the mtichines are aecordingly designed for this btisic insulation (BIL) only. When the prospective surges are expected to be more severe than this, separate protection becomes imperative. This is particularly important for a rotating machine w hich, besides being a dry equipment, also has only a limited space within the stator slots and hence has the smallest BIL of all, as is evident from Table I 1.6. compared to Tables 14.1, 32.1(A) and 13.2. For its comprehensive protection it can be considered in two parts,... 

Glowing embers, brands Drying equipment Molten metal or glass Heat transfer salt Hot oil/salt transfer lines... 

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