exit Flashcards
When one of the fluids is highly corrosive and has a fouling tendency, it should flow:
Preferably flow outside the tube
This ensures easier cleaning and reduces corrosion.
Concrete tanks can be used to store:
- Iron (II) sulfate
- Saturated brine
- Sulfuric acid
- Alum
These materials are compatible with concrete storage.
Fouling factor must be included in the calculation of overall heat transfer coefficient when the liquid:
- Is of high specific viscosity
- Contains suspended solids flows at high velocity
- Is highly viscous
- Contains suspended solids flows at low velocity
These conditions can significantly affect heat transfer efficiency.
In the case of a continuous distillation column, an increase of reflux ratio may result in all of the following except:
Lower fixed charges for the column
Higher reflux ratios typically increase operational costs.
A cylindrical storage tank can have a self-supported conical roof if:
Its diameter is less than 15 to 20 meters
This design is influenced by structural stability considerations.
In a condenser, the cooling water is passed in tube side in a multiple-pass arrangement, because:
Pressure drop is reduced
This design enhances the efficiency of heat exchange.
Which of the following is the best tube material from thermal conductivity point of view alone?
Copper
Copper has the highest thermal conductivity among common materials.
The presence of Mn in steel improves its:
- Corrosion resistance
- Cutting ability
- Elasticity and creep resistance
- Abrasion resistance and toughness
Manganese enhances several mechanical properties of steel.
Which of the following is correct regarding the design of pressure vessels?
Design pressure > operating pressure
This ensures safety and accounts for pressure fluctuations.
What is the value of Lf for a predominantly fluids processing plant?
6
This Lang factor is used for estimating fixed capital costs.
What information does scheduling in a manufacturing plant provide?
Time of starting of job and about how much work should be completed during a particular period
Effective scheduling aids in resource management.
Which of the following is not part of the working capital?
Transport facilities
Working capital typically includes inventory and other current assets.
How does change in pipe diameter affect the pumping cost for a given fluid?
Increase in diameter means decrease in pumping cost
Larger diameters reduce resistance and energy consumption.
Which of the following is incorrect, in the case of a chemical process plant?
Manufacturing cost = direct production cost + fixed cost + plant overhead cost
This equation misrepresents the components of manufacturing cost.
The utilities cost in the operation of chemical processing plant are considered:
Plant overhead cost
Utilities are necessary for operations but not directly tied to production.
The accuracy of order-of-magnitude estimate is:
-10 to +15%
This range indicates the estimated variability in cost estimates.
An autocatalytic anodic reaction process, this type of corrosion is an extremely localized attack that results in a hole in the material.
Pitting
Pitting corrosion can lead to unexpected failures in materials.
The reboiler of most industrial-scale distillation systems are of this type.
Shell-and-tube heat exchanger
This design is favored for its efficiency and capacity.
Which method of profitability evaluation of a project does not account for investment cost due to land?
Payback or payout period
This method focuses on cash flow recovery rather than total investment.
In a manufacturing plant, break-even point occurs when _____
Total annual product cost = total annual sales
At this point, the business neither makes a profit nor incurs a loss.
Which parameter determines the speed of which a first-order system responds to disturbance?
Time constant
The time constant indicates how quickly the system reacts.
The output bias of a proportional controller is known as _____
Offset
Offset occurs when a controller does not eliminate steady-state error.
The industry-accepted symbols for drawing P&ID are based on standards developed by the ISA, which stands for _____
Instrumentation, Systems, and Automation Society now International Society of Automation
ISA has established key standards for instrumentation.
These are simple devices that are widely used to control sequential and batch processes.
Programmable Logic Controllers
PLCs are versatile and widely adopted in automation.
What is the most common linear stem-motion control valve?
Globe
Globe valves are known for their flow regulation capabilities.
A _____ is a compact device that maintains the process variable at a specific value in spite of disturbances in load flow.
Regulator
Regulators are essential for maintaining system stability.
Which of the following is at the core or center of the layers of safety protection in chemical plants?
Basic controls
Basic controls are fundamental to ensuring operational safety.
What do you call devices that convert measurements to physical entities that can be transmitted with ease?
Transducers
Transducers play a critical role in control systems.
Which of the following is never used as a final control element?
Flowmeter
Flowmeters are measurement devices, not control elements.
Which control action eliminates offset?
Integral
Integral control actions help to eliminate steady-state errors.
For a faster response, the integral time parameter of a composite controller (i.e., PID) must be _____
Adjusted to a lower value
Lower integral times lead to quicker system responses.
The most important hardware component of any control system is the:
Final control element
The final control element directly influences process outcomes.
Which of the following describes a (first-order) pulse transfer function with delay?
Ke(-θs) / (τs + 1)
This transfer function accounts for time delays in system response.
An interest rate of 1% per month is the same as:
All of these
Different expressions represent the same effective interest rate.
An interest rate of effective 12% per year compounded monthly is nearest to:
1% per month
This conversion reflects the compounding effect.
Which of the following methods of calculating depreciation gives the maximum value computed for the entire useful life of the equipment?
Diminishing balance
This method allows for higher depreciation in early years.
The operating profit of a chemical manufacturing plant is equal to _____
Profit after tax + depreciation
This reflects the true profitability of operations.
