Combination step pressure drop

As shown in Step 1 of Fig. 3, the fluid flowing in the dilute phase has to support the discrete particles it contains as well as the clusters in suspension, and the combined forces result in a pressure drop equal to that of the parallel dense-phase fluid flow ... 

For the case of isothermal operafion with no pressure drop, we were able to obtain an analytical solution, given by equation B, which gives the reactor volume necessary to achieve a conversion X for a gas-phase reaction carried out isothermaliy in a PFR, However, in the majority of situations, analytical solutions to the ordinary differential equations appearing in (he combine step are not possible. Consequently, we include POLYMATH, or some other ODE solver such as MATLAB, in our menu in that it makes obtaining solutions to the differential equations much more palatable, ... 

Multichordal downcomers can increase weir length (Fig. 6). Fig. 6 shows a combined multichordal and stepped downcomer. The increased weir length decreases the liquid crest height over the weir. This decreases total tray pressure drop. The stepping is a variation of a sloped downcomer. The step increases the downcomer inlet area with a minimum decrease in tray active area. 

Timewise, exhaustion is much longer than all the other steps combined, and is practically equal to cycle time, cycie- Particle diameter in a packed bed influences both pressure drop and kinetics of ion exchange. For rigid, spherical particles like ion exchange beads, the pressure drop under laminar conditions can be estimated from the following equation... 

An elegant means of gathering intrinsic data is the use of microtechnology, where heat and mass transfer as well as pressure drop can be characterized with great accuracy. Combined with proper resources (like catalyst particle size), microreactors provide direct access to the imderlying mechanisms and the kinetics of the various steps. 

The first step involves the preparation of 1 -(3-isobutoxy-2-chloro)propyl pyrrolidine as an intermediate. 345 ml of thionyl chloride dissolved in 345 ml of chloroform are added, drop by drop, to 275 g of 1 -(3-isobutoxy-2-hydroxy)propyl pyrrolidine dissolved in 350 ml of chloroform, while maintaining the temperature at approximately 45°C. The reaction mixture is heated to reflux until gas is no longer evolved. The chloroform and the excess of thionyl chloride are removed under reduced pressure. The residue is poured on to 400 g of crushed ice. The reaction mixture is rendered alkaline with soda and the resulting mixture is extracted twice with 250 ml of diethyl ether. The combined ethereal extracts are dried over anhydrous sodium sulfate. After evaporation of the solvent the residue is distilled under reduced pressure. 220 g of product are obtained having the following properties boiling point = 96°C/3 mm, n074 = 1.4575. 

B. 10-Metkyl-10,9-borazarophenanthrene. The tan bis(10,9-borazarophenanthryl) ether from the previous step is transferred to a dry, 5-1., four-necked flask equipped with a mechanical stirrer, a nitrogen inlet, a 1-1. pressure-equalized dropping funnel, a thermometer, and a very efficient reflux condenser with a drying tube packed with silica gel at the top (Note 9). A 3.2-1. portion of anhydrous ether is placed in the flask, and the mechanical stirrer is started. The flask is cooled in an ice bath, and 700 ml. (2.1 moles) of 3M methylmagnesium bromide solution in ether (Note 10) is added dropwise through the funnel during 1 hour. The reaction mixture is heated under reflux overnight. The mixture is cautiously and slowly poured into 11. of ice water and then cautiously acidified with 385 ml. (10% excess) of 6N hydrochloric acid. The ether layer is separated, and the water layer is extracted with five 400-ml. portions of ether. The combined ether fractions are washed with 200 ml. of saturated sodium bicarbonate solution the sodium bicarbonate solution is washed with 300 ml. of ether, which is added to the other ether fractions. 

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