Blower references

The basic fluid-bed unit consists of a refractory-lined vessel, a perforated plate that supports a bed of granular material and distributes air, a section above the fluid bed referred to as freeboard, an air blower to move air through the unit, a cyclone to remove all but the smallest particulates and return them to the fluid bed, an air preheater for thermal economy, an auxiUary heater for start-up, and a system to move and distribute the feed in the bed. Air is distributed across the cross section of the bed by a distributor to fluidize the granular soflds. Over a proper range of airflow velocities, usually 0.8-3.0 m/s, the sohds become suspended in the air and move freely through the bed. 

With reference to Figure 4, each piston down-stroke provides power, while each upstroke provides compression of the blower/turbo-supplied cylinder air. The actual number of degrees of both of these strokes will vary based on the specific engine make and model, and its year of manufacture needed to comply with U.S. Environmental Protection Agency (EPA) exhaust emission limits. 

The capacity rating of blowers manufactured by the several companies are similar however, the basis of an inlet ff per min volume flow can vary depending on the design ratings published in the respective literature. Therefore, it is important to carefully examine the particular reference standard. Most units are rated for air and must be corrected by the factory representative for conditions of other process gases. 

Another operational limit in the CFB system involves gas suppliers. Three types of gas suppliers, i.e., a reciprocating compressor, a blower with throttle valve, and a compressor, are commonly used in the CFB system. For blower operation, as the gas flow rate decreases, the pressure head of the blower increases. For compressor operation, the pressure head of the compressor can be maintained constant with variable gas flow rates. The interactive behavior between a CFB system and a blower can be illustrated in Fig. 10.9, where dashed curves refer to the blower characteristics and solid curves refer to the riser pressure drop. At point A, the pressure drop across the riser matches the pressure head provided by a blower thus, a stable operation can be established. Since the pressure drop across the riser in fast fluidization increases with a decrease in the gas flow rate at a given solids circulation rate, a reduction in the gas flow rate causes the pressure drop to move upward on the curve in the figure to point B with an increase in the pressure drop of Spr. In the case shown in Fig. 10.9(a), with the same reduction in the gas flow rate, i.e., SQ, the increase in the pressure drop, Spr, from point A to point B is greater than that which can be provided by... 

Barometric pressure is detected by bellows against a reference, which is provided by a sealed-in vacuum. Exposing the instrument to direct sunlight, radiant heaters, or to direct drafts, such as from open windows or doors, should be avoided. Air temperature is measured with a platinum resistance thermometer. It is placed in a long tube that has been painted white on the outside to reflect solar radiation. A small blower pulls ambient air into the tube and across the thermometer. 

Acidic and Neutral Extract Reference Solutions. Prepare solutions in chloroform of authentic samples of drugs as indicated in Table 1, each drug being at a concentration of 1 mg/ml. Method. Divide a TLC plate (silica gel G, 250 iLim) into 8 equal columns by scoring lines with a spatula, and draw a horizontal line 10 cm from the origin, ply 10- li1 aliquots ofthe reference solutions and 25-p, aliquots of the sample extract to the columns on the plate in die sequence shown in Table 1. Evaporation of the spots can be hastened by the use of a cold air blower. 

Method. Apply 25 p, of the reference solution to the first column of the plate, and apply 25 ]al of the acidic extract from the solvent extraction mediod, or of the column extract, to the next column on the plate. Use a lOO-p, gas-chromatography syringe for Ihe application, taking great care to wash the syringe several times with chloroform between the application of each extract. Develop the plate in a tank containing chloroform acetone (4 1) (System TD, p. 168). After development, remove the plate and dry under a hot-air blower. 

The extract is examined using silica gel G plates and ethyl acetate as the mobile phase (System TF, p. 168). Score the plates vertically to bring about an even movement of the mobile phase, and score a horizontal line 10 cm from the bottom of die plate to mark the distance travelled by the solvent front Dissolve the residue from the extract in 100 jiil of acetone and immediately apply 30 )li1 to die plate at the same time apply lO-pl portions of each reference solution. After development, dry the plate with a hot-air blower. 

TB-1-25 blower blew the air through the material. The regulating valve in the blower s inlet maintained the air consumption. The amount of the consumed air was measured by a calibrated round-edged nozzle (length-diameter ratio 1/d = 4.3) which refers to the consumption coefficient ji=0.97. The nozzle was placed in the chamber for gas velocity levelling. The air pressure near the nozzle was measured by a liquid U-shaped manometer. The amount of air passing through the layer was calculated by ... 

Referring to the flow sheet in Figure 22.1.19 the regeneration gas is circulated by blower V-2 to the gas heater, the header 8 to the bed being regenerated. The effluent gas is passed to the header 9, cooler, molecular sieves (or water condenser), to the chiller for sol-... 

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