Feed solids concentration

The method is apphcable for unflocculated pulps or those in which the ionic characteristics of the solution produce a flocculent structure. If polymeric flocculants are used, the floccule size will be highly dependent on the feed concentration, and an approach based on the Kynch theoiy is preferred. In this method, the test is carried out at the expec ted feed solids concentration and is continued until underflow concentration is achieved in the cyhnder. To determine the unit area, Talmage and Fitch (op. cit.) proposed an equation derived from a relationship equivalent to that shown in Eq. (18-45) ... 

Agitation by a wide spatula may be substituted for hand agitation, but only after it has been determined by feel that the spatula will provide the needed agitation. If this cannot be done, then confirmation of proper agitation must be based on back-calculated feed solids concentrations and/or particle size analyses of the filter cakes. 

The solids recovery in the cake can be inferred from measurements using Eq. (18-90). It is shown as a function of G-seconds for different feed solids concentration in Fig. 18-141 see also theoiy discussed below. 

For a properly designed and operated cyclone, the sharpness index is constant, typically 0.6. The cut size and apparent bypass are a function of the cyclone geometry, the volumetric feed rate, the material relative density, the feed solids concentration, and the slurry rheology. The relationship for a standard cyclone geometry, where if D. is the cylinder diameter in cm and inlet area = 0.05 D vortex finder diameter = 0.35 Dc ... 

Benefits of Prelltickeniug. The feed solids concentration has a profound effect on the performance of any cake filtration equipment. It affects the capacity and the cake resistance, as well as Uic penetration of the solids into [lie cloth which influences filtrate clarity and medium resistance. Thicker feeds lead to improved performance of most filters through higher capacity and lower cake resistance,... 

The zeolite and the resin adsorbents show different adsorption isotherm characteristics, particularly at higher concentration (51). The resin adsorbent isotherm is slightly concave upward, whereas the zeolite isotherm is linear, or even slightly concave downward. Resins, therefore, have an advantage in a UOP Sarex operation that involves high feed-solids concentration. 

Type of centrifuge G/g Minimum feed solids concentration by wt. Minimum mean particle size, lm Minimum m/s... 

Scroll/decanter Continuous 5-50,000 200 1. Continuous solid discharge 2. High-feed solid concentration 1. Turbulence created by scroll 2. Low centrifugal force Antibiotic production... 

Feed solid concentration Solid particle size (nun) ... 

There is clearly a need to investigate the mechanism of attrition to relate it to the fracture properties of the solids, and to develop a realistic attrition index , similar to that used for abrasion in cyclones. Such an index would indicate the relative importance of operating conditions and design variables such as inlet velocity, feed solids concentration or cyclone diameter. This could then be used in scale-up to predict (or minimize) the effect of the shape, the particle size distribution or the hardness and strength of the feed solids, if known, may allow such predictions without any experimental tests. Generally, better understanding of attrition and its relation to abrasion may lead to better equipment design and operation. 

Particle diameter 20 pm to 1 cm feed solid concentration >50% sohds. Liquid contamination in exit solids 0 to 20% v/v liquid. Use batch for <40 g/s use continuous for >280 g/s. Select inihally on temperature sensitivity. Prefer adiabahc over conduction. 

Particle size 0.1 to 300 pm try to avoid using a thickener for particle diameters >200 pm, especially if their density is >2 Mg/mL Feed solids concentration 0.01 to 20% v/v exit liquid contamination in the solids exit 80 to 90% v/v liquid. Deep cone thickener exit liquid contamination in the solids exit 30 to 40% v/v liquid. 

High-speed disc, intermittent solids ejecting particle diameter 1 to 500 J,m feed concentration solids 2 to 6% v/v and <5% w/w. High-speed disc, continuous nozzle discharge particle diameter 0.1 to 500 am feed concentration solids 5 to 30% v/v <10% w/w. Usually select when have a large amount of fines. Horizontal scroll discharge (solid bowl decanter) 10 to 5 x 10 m/s particle diameter 2 to 5,000 am feed solids concentration 0.5 to 50% v/v. Usually >10% v/v. Only option when feed concentration >40% v/v sohds. 

Semicontinuous horizontal basket, pusher discharge particle diameter 50 to 5000 pm feed solids concentration 15 to 70% w/w. Capacity 0.3 to 7 kg/s. Product dryness 85 to 98%. Free draining. Main advantage is to rinse the solids. 

Continuous horizontal combo solid-screen, scroll discharge particle diameter >150 pm feed solids concentration 10 to 75% w/w. Solvent-based reactions. Vertical or horizontal cone slip discharge continuous, particle diameter >200 pm feed solids concentration 10 to 80% w/w, capacity 0.25 kg/s. Dewater crystals and free draining libers. Vertical cone, scroll discharge continuous, particle diameter 200 to 5,000 pm feed solids concentration 5 to 60% w/w. Capacity 0.02 to 8 kg/s. Horizontal cone oscillating/torsional vibration... 

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