Chemical Engineering

im thinking its 2*pi[as in the constant 3.14...]*radius*length

im guessing this gives are of a cylinder

production optimization is increasing the quality&quantity of products

The hydro-testing procedure of a shell and tube heat exchanger requires you to fill the shell and tubing with water that had a color dye added to it. Then, raise the internal pressure by 1.5 times the operating pressure suggested by the manufacturer. If there are any cracks in the vessel, the water will be forced out through the cracks.

From the Bernoulli equation, pressure drop increases with the square of velocity. So if the velocity is doubled the pressure drop will increase by a factor of four.

You usually need at least a bachelor's degree in chemical engineering to enter this field. Some engineering colleges offer work-study programs that combine work experience with formal study. It generally takes four or five years to earn a bachelor's degree in engineering. Many jobs in chemical engineering also require advanced degrees. You can earn a master's degree in one or two additional years of full-time study. Many chemical engineers find that a master's degree in business administration is useful, especially if they want to become managers. If you want to do research or teach at the university level, you will need a doctoral degree. It usually takes about four years of full-time study beyond the bachelor's degree to earn a doctoral degree. Many engineers continue their education on a part-time basis after they have found jobs in their field. Employers often pay tuition for courses that engineers take to improve their job skills. Chemical engineers must be willing to study throughout their careers so that they can keep up with advances in engineering technology.

Engineers who offer their services to the public or whose work affects life, health, or property must be licensed by the state in which they work. They generally need a degree from an approved engineering college, about four years of work experience as an engineer, and a passing grade on a state examination before being licensed as a professional engineer.

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°API = [ 141.5 / (SG @ 60°F) ] - 131.5

SG= specific gravity (always taken at 60°F when calculating API)

243 is used on oily surfaces that can't be cleaned.

Nobody cares

The use of the LMTD arises straightforwardly from the analysis of a heat exchanger with constant flow rate and fluid thermal properties. It is a simple method to approximated the temperature diving force in a heat exchanger. The LMTD is a logarithmic average of the temperature difference between the hot and cold streams at each end of the exchanger. The larger the LMTD, the more heat is transferred.

forms a sediment when it sinks to the bottom of a liquid.

orsat apparatus

empiracal models

The word 'coagulant' is usually used by people when they want to explain why cuts have stopped bleeding. Water purification, particularly on an industrial scale, uses Chlorine to kill harmful bacteria with water passing through various size filters to remove or clean the water before people can drink the water

The rate of transfer of a process is equal to the driving force divided by the resistance.

The mass transfer coefficient is the resistance to mass transfer. In mass transfer the driving force is the concentration gradient. The mass transfer coefficient is considered anything that contributes to resistance to mass transfer: thermal and eddy diffusivity, distance, etc.

Fick's law of diffusion describes convective mass transfer as:

N=-c*D*(ca2-ca1)/(z2-z1)

where:

-c is some constant multiplier (unitless)
-The quantity (z2-z1) is the distance between two points. (length i.e. meters)
-D is the mass diffusivity or the diffusion coefficient and is dependent on properties of the substance (such as particle size etc.) and temperature. (units: length2/time i.e. m2/s)
-The quantity (ca2-ca1) is the concentration gradient between the same two points (the driving force) (units: amount/length3 i.e. mol/m3)
-N is the rate of mass transfer (units: mass/(length2*time) i.e. mol/m2*s) )

Putting Fick's law in terms of the mass transfer coefficient kc', yields:

N=-kc'*(ca2-ca1)

where kc'= -c*D/(z2-z1).

You can see that the mass transfer coefficient is in fact a function of the diffusivity.

The biggest advantage arise from the square root dependence on the diffusion coefficient. This allows one to better predict the behavior of various solutes with different diffusion coefficients based on measured behavior of one particular solute. The square root dependence gives more accurate prediction than the linear dependence found with the two-film model. Recognize however that surface renewal is really most accurate when surface renewal rates are high. The model developed by Toor that combines film and surface renewal can be used for quite a range of surface renewal rates.

It depends on the context. In a.c. circuits, 'reverse polarity' describes a situation in which a device, such as a socket outlet, is wrongly wired -with the line and neutral conductors interchanged.

All types of dust that are not fully oxidized will burn and potentially explode. This includes metal dust such as aluminum, or organic materials such as grain or sugar dust. If a [solid] substance can burn, it can be explode as a dust if the right conditions are present.

A distillaton column works byh contacting vapor and liquid phases. Without reflux traveling down the column the trays will not have sufficient vapor-liquid contact to induce a mass transfer between the phases, and separation will be poor to non-existent.

The nominal pipe size is closest to the inside diameter; however, for exact calculations both should be looked up in a table based on the scheduled pipe size.

The Diesel Index indicates the ignition quality of the fuel. It is found to correlate, approximately, to the cetane number of commercial fuels. It is obtained by the following equation

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water breakthrough is concerned with oil production wells. when a layer of water under the oil layer channeling into the oil accumulation, it called water breakthrough or water coning phenomena.

When more overhead liquid product is refluxed in a distillation column the liquid rate in the column increases. This may or may not be an optimal change in the column. Too little reflux will not have the proper vapor-liquid contact to promote separation and the overhead product will may meet the desired concentration specification. Too much reflux will flood the column and lead to wasted energy and cooling utilities associated with condensing more vapor than necessary. On a McCabe Thiele diagram for a binary distillation, increasing the reflux will decrease the slope of the stripping operating line. Typically the optimum reflux ratio (overhead product sent back to the column divided by distillate removed) is the theoretical minimum reflux ratio multiplied by a factor of 1.2-1.5.