Where, N B is the blend number, n is revolutions per second, D is the diameter of the impeller, m, T is tank diameter, m, and θ is time in second. Blend number (N B) attempts to predict the effect of impeller D/T on the results: The impeller blend number, N B, is used to predict the blend time, θ, in a mixed system. Where, N p is the power number, P is the power of the mixer, Watt, D is the diameter of the impeller, m, n is revolutions per second, and ρ is the density of the concentrate, kg/m 3. The impeller power number, N p, is used to predict impeller power, P, directly and torque, t, indirectly: Dimensionless numbers are affected by geometric factors, such as the ratio of impeller to tank diameter, D/T, and the ratio of clearance from the tank bottom to tank diameter, C/T. These numbers can be used to quantify the performance characteristics of an impeller. All must be determined experimentally for a given impeller configuration. There are several important dimensionless numbers that are required to design mixers. Later, the discharge flowrate number was correlated as a function of the paddle dimensions by an experimental investigation set up by Yuji. The results were presented in the form of graphical characteristics of power consumption and mathematically in the form of dimensionless equation. Kamienski, examined the influence of vessel diameter to mixer diameter ratio on power consumption. It is clear that both vessel and impeller diameters have to be adapted to take these properties into account for distributive as well as dispersive mixing. Ĭhemical engineers and food processors often deal with complex fluids in laminar regime which are, usually, highly viscous and shear thinning. These comprise mixers for Rushton, dispersing and dissolution into liquids, blending of particulate material, and mixing of solids and liquids to form doughs, batters and pastes. Mixers for the food processing and agricultural industries are reviewed and classified into three categories according to the materials to be mixed. There are many publication on flow properties of juice concentrates and effects of temperature and concentration which most of them are based on viscometry data. Therefore complex models are developed to describe their behavior. Most fluid foods do not have the simple Newtonian rheological model, hence, their viscosities are independent of shear rate or shear stress and constant with temperature. Viscosity and its variation with concentration and temperature are very important for the food industry in general and for fruit derivatives in particular, since it is necessary for the design and the optimization of several processing operations (e.g., pumping, evaporation, membrane filtration etc. ![]() They benefit the producer, the industry and the consumer. These properties influence the treatment adopted during processing, and they are good indicators of other properties and qualities of food. In food industry, knowledge of the physical properties of food is fundamental in analyzing the unit operations. ![]() Concentration has also solved the problem of seasonal nature of crops and allowed economic utilization of perishable agricultural products. Now, apple juice concentrate may be stored and shipped throughout the world as a relatively stable product. At that time, the greatest volume of apple juice was processed into 70 -75☋rix concentrate to reduce volume and weight, which resulted in lower costs for packaging, storage and transportation. Annual world apple production was estimated to be more than 40 million tons in 19, of which more than 5 million tons were processed to obtain apple juice. Apples are amongst the most widely grown and consumed fruit crops.
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