Specific drying energy

The specific drying energy is the energy for heating the air Ho related to the enthalpy of evaporation. From the above equations results... 

Batch versus continuous Flowsheet input-output structure Crystallizer and recycle considerations Separation systems specification Product drying Energy systems... 

One of the first applications of biodegradable materials is based on the cooked, extruded, and expanded starch known from the food and chemical sectors (Fig. 14.23). Starch is cooked with water in the extruder and chemically modified as necessary or mixed with plasticizers, then expanded to a starch foam and dried. The extrudate is ground so that the functional properties thus created can be used in the food/chemicals sector. The foamed, cut, and dried extrudate is the end product for loose-fill packaging applications. The degree of expansion is a measure of the foam texture. It increases strongly with product temperature at the die, helped by a higher specific mechanical energy input. However, both measures increase the water-solubility of the product. 

Application of the Ohm s law analogy allows construction of combined series parallel thermal circuits to describe a specific drying application. The flow of heat energy through the circuit shown in Fig. 3 can be described as... 

Rate of evaporation Specific drying rate Specific energy consumption... 

Not all surfaces exhibit surface melting it appears to depend on the specific free energy Ay that the dry solid surface has in excess of a solid surface wetted by its own liquid. For positive values of Ay, the surface lowers its free energy by melting for negative values, it stays dry. The condition for surface melting is more readily fulfilled for open surfaces such as fcc(l 1 0) than for close-packed ones. In accordance... 

Figure 23. Specific mechanical energy (SME) input of the treatments with different screw configuration (under 40% moisture content based on dry starch) and barrel moisture content (Tang et al., 2008c).

The theoretical energy requirement for the burning of Portiand cement clinker can be calculated from the heat requirements and energy recovery from the various stages of the process. Knowledge of the specific heats of the various phases, and the heats of decomposition, transformation, and reaction then permits calculation of the net theoretical energy requirement of 1760 kj (420 kcal) for 1 kg of clinker from 1.55 kg of dry CaCO and kaolin (see Clays) (8). 

The relationships between specific heat and water content and between specific heat and ash content are hnear. Given the specific heat on a dry, ash-free basis, it can be corrected to an as-received basis. The specific heat and enthalpy of coal to 1366 K (2000°F) are given in Coal Conversion Systems Technical Data Book (part lA, U.S. Dept, of Energy, 1984). 

This legislation was formally adopted on 26 November 1988. It applies to plant for the production of energy (effectively, boiler plant and similar) and specifically excludes heating furnaces, drying plant, etc. The Directive applies to plant of thermal input 50 MW and over. If two or more separate plants are in close proximity such that... 

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