# Tutor profile: Tahir S.

## Questions

### Subject: Physics (Fluid Mechanics)

Why is a centrifugal pump referred to as a high discharge pump?

A centrifugal pump is an example of a kinetic device. Centrifugal force is used to drive the fluid out of the centrifugal pump. Thus, the liquid entering the pump gains kinetic energy from the impeller's rotation. The impeller's centrifugal force propels the liquid to a high velocity, imparting mechanical (rotational) energy to it. As a result, it releases the liquid at a rapid rate. It is denoted by the equation below: Centrifugal force F= (M*V2)/R. Where, M-Mass V-Velocity R-Radius

### Subject: Basic Math

Solve the following system of linear equations by substitution method: 3x – y = 5 x + 4y =20

3x – y = 5 eq(1) y = 3x – 5 eq(2) x + 4y = 20 eq(3) Put the value of y from eq(2) in eq(3) x + 4(3x – 5) = 20 x + 12x – 20 = 20 13x = 40 x = 3.07 Put the value of x in eq(2) y = 3(3.07) – 5 y = 4.21 Final Answer: x = 3.07, y = 4.21

### Subject: Chemical Engineering

Suppose an absorber Column for CO2 capture from flue gas in which CO2 is absorbed through the chemical absorption in an amine solvent. There are two input streams: amine solvent and flue gas. The two output streams are sweet gas and rich solvent. (1) How you will control the composition of CO2 gas in sweet gas? (2) What are the process control strategies used for the effective control of such processes?

(1) There are multiple ways to control and monitor the CO2 composition in sweet gas. It can be controlled through the input conditions of the input streams such as temperature, pressure, mass fractions. However, for accurate and effective control, a control valve can be installed at the input stream of amine solvent. The rate of absorption depends significantly on the amount or flow rate of amine solvent. The amount of flow rate of the amine solvent is controlled through a control valve. The less valve opening corresponds to the less amount of amine solvent available for CO2 absorption, which results in more composition of CO2 available in the sweet gas stream. (2) The most commonly used process control strategies include Proportional-Integral (PI) controller, Proportional-Integral-Derivative (PID) controller and Model Predictive Control (MPC).