Which impeller is effective in lifting solids from the base of the tank?

The impellers, which generate the axial flow in a vessel with baffles, were found to have a higher performance to suspend solids off the tank bottom. For the mixing tank without baffles, radial-flow impellers were found performed better than axial flow impellers.

What is agitation process?

Generally, agitation refers to forcing a fluid by mechanical means to flow in a circulatory or other pattern inside a vessel. Mixing usually implies the taking of two or more separate phases, such as a fluid and a powdered solid or two fluids, and causing them to be randomly distributed through one another.

Why do we need agitation in a reactor?

If there is no agitation in a reactor, the reaction will be slow or stop, and unreacted chemicals will accumulate. In an exo- thermic reaction this is a serious hazard. If you re- start the agitator, there will be a lot of unreacted material available and the reaction may be very fast.

What is the agitator used for?

Traditional agitators are tall spindles, vaned or finned, in the center of the wash basket that twist (or agitate) back and forth, rubbing against clothes to help break down loose soils.

What is the use of agitator in tanks?

An Agitator is a machine used in a tank for mixing various process media together. Media include all liquid types, gases & solids (such as salts, powders, granules etc). In summary, it works by rotating an impeller to impart energy to the media which interact and mix.

How to project on heat transfer surfaces in agitated vessels?

The project on heat transfer surfaces in agitated vessels is based on the determination of the heat exchange area, which is necessary to abide by the process conditions as mixing quality and efficiency of heat transfer. The heat transfer area is determined from the overall heat transfer coefficient (U).

What is the heat transfer coefficient of a jacketed agitated vessel?

Question: A jacketed-agitated vessel is used for heating water (C = 4.18 kJ/ (kg K)) from 10 °C to 80 °C. The heat transfer coefficient for water (in kW/ (m2 K)) is given by: [hi = 1.5 n2/3], where n is the impeller speed in rev/s.

What do we know about the heat transfer coefficient of agitators?

One of the focal researches in the heat transfer of agitated vessels is the study by Dream et al. [9] that identified the distinctive sorts of the jacketed vessels and conducted the set of correlations for both inside and outside heat transfer coefficients, according to the type of the agitator and the design of jacket respectively.

What are the agitation variables for a given tank and impeller?

For a given tank and impeller geometry, the only agitation variable is the shaft speed, N. Since the Reynolds number is to the 1/3 power in the Nusselt number equation, the process-side convective heat-transfer coefficient is proportional to N1/3.