Basic concepts in chemical engineering. Part 1
Hello friends of steemit in my presentation to this social network tell them that I was a graduate in petrochemical engineering that is why I dared to make a post with some of the basic concepts that can be studied in this wonderful career with basic knowledge of chemistry , math and physics seeks to obtain petroleum derivatives for everyday use in our lives., since to carry out the work of refining petroleum the sciences and basic concepts are fundamental.
Density
It is the relation between the mass and the volume of a fluid, the daily example is that of water with oil, where when trying to mix them, the oil stays in the upper part since its density is lower than that of water, it is expressed as :
Its units are:
gr / cm3 = gr / ml
kg / L = 1000 kg / m3
lb / pie3
The density of liquids unless handled at very high pressures does not show significant variations
The density values for liquids are found in tables. The density of the water at 20ºC to 14.7 psi is 1 gr / cm3 or 1000 kg / m3.
The density of the gases depends on the temperature and operating pressure. For ideal gases, it can be calculated using:
R = Universal gas constant
M = Molecular weight of the gas
T = temperature
Relative density
Also known as specific weight, it is the ratio between the densities of two different fluids at the same temperature. Generally for liquids the water at 20 ºC is used as reference and for gases the air is used as a reference at 20 ºC and 1 atm of pressure. It is also known as dynamic viscosity, its symbol is xpresa the ease that a fluid has to move when an external force is applied, that is, it is a measure of its resistance to displacement or to suffer internal deformations.
The units for its measurement are Pascal and Poise.
Kinematic viscosity
It is the quotient between the dynamic viscosity of a fluid and its density
Reynold number
It is the relation of the dynamic forces of the mass of the fluid with respect to the deformation efforts caused by the viscosity. It is a dimensionless quantity given by:
Where:
When calculating the Reynolds number according to the result, we obtain the flow regime with which we are working since these can be laminar which is characterized by the sliding of concentric cylindrical layers one over the other in an orderly manner. The fluid velocity is maximum at the pipeline and decreases rapidly until it becomes zero at the pipe wall. and its result is less than 2000.
Turbulent fluid
It is characterized by an irregular and indeterminate movement of the fluid particles in directions transverse to the main direction of flow. The distribution of speeds is more uniform through the diameter of the pipe. Your Reynolds number is: and its result is greater than 4000.
Bernoulli's Theorem
It is a form of expression of the application of the law of conservation of energy to the flow of fluids in a pipeline.
The total energy at any point above an arbitrary horizontal plane set as a reference is equal to the sum of the geometric height, the height due to the pressure and the height due to the velocity.
If there are no friction losses or there is no additional energy input (pumps or turbines) inside the pipe, the height Z should remain constant at any point in the fluid. However, there are losses caused by the friction of the fluid with the pipeline and by obstructions that the line itself may have.
For more information visit the following links.
https://www.biografiasyvidas.com/tema/densidad.htm
https://es.wikipedia.org/wiki/N%C3%BAmero_de_Reynolds
https://hernanleon1002.wordpress.com/fisica-de-fluidos-y-termodinamica/segundo-corte/marco-teorico/principio-bernoulli/