Concentration batch

Equilibration conditions Additive concentrations Batches of reagents Detector wavelength Sample loading conditions (t j, Ap)... 

Once 5000 L of surface water was attained, all previously concentrated batches were added into the feed tank for further concentration. All batches were stored in a refrigerator. 

Results of two batches are shown, the first batch is in standard operation while the last batch is the final concentration step of all previous concentrate batches. In the last concentration step a concentration factor of approximately 250 was attained. 

When the concentrate batches were added flux declined rapidly. This could be due to an increased osmotic pressure, increased viscosity of the solutions, or adsorption of material on the membrane or, more likely, a combination of aU of these effects. No precipitation occurred in the tank. After the last batch was concentrated, the RO was rinsed with pure water (permeate). Flux was strongly influenced by temperature, which was responsible for most flux changes occurring during usual operation. The graph showing temperature dependence is shown in Figure A1.8. 

Harily Clean-in-place (CIP) Compress Concentrate (batch)... 

The description of a process at the laboratory stage usually only gives specific values for parameters such as temperatures, quantities of reactants and solvents, times of addition and so on. A hazard assessment of such a process would not consider the small variations in the process conditions that occur in normal operation and are not considered as abnormal (small changes in temperature, concentration, batch times and so on). 

However, Al-Hashem et al. [34] reported another example of dual biocide treatment where a high concentration batch treatment by a biocide was followed by a low concentration of continuos biocide treatment. The first step had been introduced to reduce the numbers of the bacteria (batch treatment) and keep it low (continuous treatment). Those authors, after not finding such treatments feasible enough both in terms of the extra time to be allocated for each treatment and the costs of the chemicals and facilities, prefer a batch dose of high concentration with special consideration of factors such as the frequency of biocide application and pre-treatment of the water entering into the system. 

The silane pre-treatment of nano-silica is based on the consideration of the fact that graft polymerization onto nanoparticulate surfaces in molten PP is more difficult than in solution of the polymer. To further increase collision between nano-silica and the monomer mider melt mixing, concentrated batches should be made by incorporating nano-silica and graft monomer into small amounts of matrix polymer. Then, the concentrated batches can be diluted into desired concentrations to prepare nano-silica/PP composites. 

Many antistatic additives are either liquid at room temperature or melt at temperatures below the processing temperature. Often liquid antistatic additives are sold in solid form, as they are absorbed on a carrier such as silica, or they are in the form of a highly concentrated batch. 

Achieving an appropriate concentration of the free drug and quantification of that concentration, variation in drug concentration (batch-to-batch),... 

Multiple reactions in parallel producing byproducts. Consider again the system of parallel reactions from Eqs. (2.16) and (2.17). A batch or plug-flow reactor maintains higher average concentrations of feed (Cfeed) than a continuous well-mixed reactor, in which the incoming feed is instantly diluted by the PRODUCT and... 

Using a batch reactor, a constant concentration of sulfuric acid can be maintained by adding concentrated sulfuric acid as the reaction progresses, i.e., semi-batch operation. Good temperature control of such systems can be maintained, as we shall discuss later. 

Pentaerythritol may be nitrated by a batch process at 15.25°C using concentrated nitric acid in a stainless steel vessel equipped with an agitator and cooling coils to keep the reaction temperature at 15—25°C. The PETN is precipitated in a jacketed diluter by adding sufficient water to the solution to reduce the acid concentration to about 30%. The crystals are vacuum filtered and washed with water followed by washes with water containing a small amount of sodium carbonate and then cold water. The water-wet PETN is dissolved in acetone containing a small amount of sodium carbonate at 50°C and reprecipitated with water the yield is about 95%. Impurities include pentaerythritol trinitrate, dipentaerythritol hexanitrate, and tripentaerythritol acetonitrate. Pentaerythritol tetranitrate is shipped wet in water—alcohol in packing similar to that used for primary explosives. 

The main features in which the Radford process differs from the batch operation are in thermal dehydration and compounding. Water-wet nitrocellulose on a continuous vacuum belt filter is vacuum-dried followed by hot air transfusion (80°C) to reduce the moisture to less than 2%. After cooling, alcohol is sprayed on the nitrocellulose to a concentration of 15—20%. The alcohol-wet nitrocellulose is then transferred from a surge feeder to a compounder by a continuous weigh-belt along with the other ingredients of the composition, which are also weighed and added automatically. 

Cg = the concentration of the saturated solution in contact with the particles, D = a diffusion coefficient (approximated by the Hquid-phase diffusivity), M = the mass of solute transferred in time t, and S = the effective thickness of the liquid film surrounding the particles. For a batch process where the total volume H of solution is assumed to remain constant, dM = V dc and... 

In the batch methylene chloride process, the sulfuric acid concentration can be as low as 1% and only limited desulfonation is required to reach a combined acetic acid content of 62.0%. With perchloric acid catalyst, the nearly theoretical value of 62.5% combined acetic acid is obtained. 

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