Reactor with Agitators

A 50-gallon, stainless steel reactor with agitator used in ice quenching of the nitration mixt... 

Such reactors are doubtlessly superior to stationary apparatuses. First and foremost, the reactors with agitators offer an improved mixing of gaseous chlorine derivative with contact mass, which increases its conversion degree. They also help to considerably reduce the baking of contact mass, which increases the degree of silicon use. Such reactors can be also used for a continuous process of organochlorosilane production. 

No liquid flow-batch slurry reactor with agitation ... 

Features - continuous stirred tank reactors with agitators are used - multiple reactor zones typically used - polymerization takes place in "solution" - organic peroxides typically used as initiators - polymer has fewer branches but of somewhat longer length relative to tubular process... 

Total Matrix 2 The Total Matrix for a First-Order. Homogeneous Batch Reactor With Agitation... 

This procedure may result in a concentration of cumene hydroperoxide of 9—12% in the first reactor, 15—20% in the second, 24—29% in the third, and 32—39% in the fourth. Yields of cumene hydroperoxide may be in the range of 90—95% (18). The total residence time in each reactor is likely to be in the range of 3—6 h. The product is then concentrated by evaporation to 75—85% cumene hydroperoxide. The hydroperoxide is cleaved under acid conditions with agitation in a vessel at 60—100°C. A large number of nonoxidising inorganic acids are usehil for this reaction, eg, sulfur dioxide (19). 

In a typical adiabatic polymerization, approximately 20 wt % aqueous acrylamide is charged into a stainless steel reactor equipped with agitation, condenser, and cooling jacket or coils. To initiate the polymerization, an aqueous solution of sodium bisulfite [7631-90-5] is added, followed by the addition of a solution of ammonium persulfate [7727-54-0] N2HgS20g. As the polymerization proceeds, the temperature rises to about 90°C, and then begins to fall at the end of the polymerization. The molecular weight obtained depends primarily on the initiator concentration employed. 

The reaction is initiated with nickel carbonyl. The feeds are adjusted to give the bulk of the carbonyl from carbon monoxide. The reaction takes place continuously in an agitated reactor with a Hquid recirculation loop. The reaction is mn at about atmospheric pressure and at about 40°C with an acetylene carbon monoxide mole ratio of 1.1 1 in the presence of 20% excess alcohol. The reactor effluent is washed with nickel chloride brine to remove excess alcohol and nickel salts and the brine—alcohol mixture is stripped to recover alcohol for recycle. The stripped brine is again used as extractant, but with a bleed stream returned to the nickel carbonyl conversion unit. The neutralized cmde monomer is purified by a series of continuous, low pressure distillations. 

Slurry Reactors with Mechanical Agitation The catalyst may be retained in the vessel or it may flow out with the fluid and be separated from the fluid downstream. In comparison with trickle beds, high heat transfer is feasible, and the residence time can be made veiy great. Pressure drop is due to sparger friction and hydrostatic head. Filtering cost is a major item. 

Into a reactor equipped with agitator and temperature control jacket is charged approximately 100 lb (about 3 lb mols) of methanol, technical. This methanol is used in excess, and so it is both a reactant and a solvent in the synthesis. 

For heat transfer fluids inside reactor jackets or other process vessels with agitation to fluids in vessels (Figure 10-93A), the heat transfer is expressed as... 

Example 2. Reactor Experiment.66 Waste PET (110 g), 800 g of ethylene glycol, and 93 g of 50% aqueous sodium hydroxide were introduced into a reactor. The reaction mixture was heated to 170° C with agitation while collecting distillate (mostly water with some ethylene glycol). The slurry, which consisted of disodium terephthalate in ethylene glycol, was filtered at a temperature of 170° C in a vacuum filter. The disodium terephthalate obtained was pressed as dry as possible and the ethylene glycol was recovered. The filter cake was washed with room temperature EG to remove impurities and to cool the disodium terephthalate to less than 100° C, followed by washing with a saturated solution of disodium terephthalate in water (maintained at 90-100° C). 

Batch Mass Reactors. The batch-mass reactors used in these processes are of two types low conversion agitated kettles and high conversion static reactors with extended cooling surfaces. 

The polymerizations were conducted in a 20-liter stainless steel reactor with a pitched-blade turbine agitator and four side-wall baffles. The monomer was polymerized at the same temperature, initiator and monomer concentration in two different inert diluents. The data (Figure 6) illustrate the substantial lowering of the overall heat transfer coefficient for the system with the more highly swollen particles. 

Mixing Models. The assumption of perfect or micro-mixing is frequently made for continuous stirred tank reactors and the ensuing reactor model used for design and optimization studies. For well-agitated reactors with moderate reaction rates and for reaction media which are not too viscous, this model is often justified. Micro-mixed reactors are characterized by uniform concentrations throughout the reactor and an exponential residence time distribution function. 

FIGURE 1.5 The classic CSTR a contitmous-ilow stirred tank reactor with mechanical agitation. 

A 100-gal pilot-plant reactor is agitated with a six-blade pitched turbine of 6 in diameter that consumes 0.35 kW at 300 rpm. Experiments with acid-base titrations showed that the mixing time in the vessel is 2 min. Scale up to a 1000-gal vessel with the same mixing time is desired. 

Stirred Tank Reactor with a Monoiithic Agitator... 

The ethylene polymerization was carried out using a 12 OZ glass reactor equipped with a two blade impeller under a constant ethylene pressure of 20 psi. A predetermined amount of solvent (n-heptane), monomer, MAO and embedded catalyst were charged in series into the reactor. Polymerization was carried out at 70"C with agitation speed of 800 rpm. The polymer obtained was washed with excess amount of methanol containing hydrochloric acid solution and dried in vacuo for 24 hrs. The polymerization rate was determined from the amount of consumed ethylene, measured using a mass flow meter. DSC analyses (Dupont V4.0B) was carried out at a rate of 10 C /min, and the results were obtained in the second scan. 

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