Role Of The Chemical Engineer In Design Flashcards
List some responsibilities of a process/chemical engineer
- Prepare process flow diagrams and heat and material balances
- Assist in calculating and evaluating the economics of a project
- Assist in the development of flow diagrams for piping and instrumentation design
- Size and review inquiry specifications for tanks, vessels, reactors, towers and other equipment
- Review specifications for equipment for utility services
- Supply basic data required for instrumentation specifications
- Size safety relief valves and flare systems
- Create flow diagrams covering vent and flare systems
- etc…
List the six basic stages of a typical chemical process
- Raw material storage
- Feed preparation
- Reactor
- Product separation
- Purification
- Product storage
List the fixed design constraints encountered during the design process (these set the outer boundary of possible designs)
- Constraints that arise from physical laws
- Government regulations
- Standards and codes
- Resources
- Safety regulations
- Economic constraints
List the flexible design constraints encountered during the design process (these set the inner boundary of possible designs)
- Choice of process
- Process conditions
- Materials
- Equipment
- Personnel
- Time
- Methods
What are the different stages a plant design project goes through
- Idea generation
- Pre-feasibility study
- Feasibility study
- Basic and final development
- Execution
- Commissioning and start-up
- Evaluation and operation
What are the benefits of breaking down the project life span into different stages
- Easier management
- Money saving decision making (stopping a failing project before a lot of money is spent on it)
Explain what happens in the design objective stage
A complete statement of the requirements should be obtained before starting. Distinguish between the real needs and wants.
Explain what happens in the data collection stage
Collecting information on possible processes, equipment performance and physical property data
Explain what happens in the generation of possible design solutions stage
The first step in devising a new process design is to sketch out a rough block diagram showing the main stages in the process and to list the primary function and major constraints for each stage.
Explain what happens sateges happens in the selection stage
The selection process goes through four stages:
- possible designs (credible) - within external constraints
- plausible designs (feasible) - within internal constraints
- probably designs - likely candidates
- best design (optimum) - best solution for problem
Name the different types of documentation that will be circulated and accumulated during a projects life span
- General correspondence
- Calculation sheets
- Drawings
- Specification sheets
- Purchase orders
Give some examples of general correspondence within the group and:
- government departments
- equipment vendors
- site personnel
- the client
Give some examples of calculation sheets
- design calculations
- costing
- computer print-out
Give some examples of drawings
- flow-sheets
- piping and instrumentation diagrams
- layout diagrams
- plot/site plans
- equipment details
- piping diagrams
- architectural drawings
- design sketches
Give some examples of specification sheets
- pumps
- heat exchangers
Give some examples of purchase orders
- quotations
- invoices
Describe the different areas of engineering practice that codes and standards cover
- Materials, properties and composition
- Testing procedures for performance, composition, quality
- Preferred sizes
- Design methods, inspection and fabrication
- Codes of practice for plant operation and safety
What are the main advantages of using codes and standards
- Best means of communication
- Communicates desire
- Utilises valuable experience and latest technology
- Lower equipment costs
- Reduced operating costs
- Improved safety and reliability
What are the main disadvantages of using codes and standards
Standards impose constraints on the designer
Describe the factors of safety encountered during the design process
To ensure that design specifications are met, factors are included to give a margin of safety in design. Design factors are applied in process design to give some tolerance in the design
Describe units of measurement during the design process
It is best practice to stick to one set of units in a design
Name the steps when optimizing a system
- Clearly identify the objective
- Determine the objective function
- Find the values of the variables that give the optimum value of the objective function
Name the general factors to consider for design over and above the ones already mentioned
- plant location
- plant layout
- plant operation and control
- utilities
- structural design
- storage
- materials handling
- waste disposal
- health and safety
- patents
- environmental considerations
- legal restrictions
Name the factors when choosing a plant site
- raw materials
- markets
- power and fuel
- climate
- transportation facilities
- water supply
- waste disposal
- labour supply
- taxation and legal restrictions
- site characteristics
- flood and fire protection
- community factors
