Control Flashcards
all operations undertaken manually
manual
the majority of operations undertaken manually but some critical parameters controlled automatically
semi-automated
the majority of the plant operations automatically undertaken, with some manual input
fully automated
maintains the process variable as close as possible to the set point
control element
A process plant undergoing ___ processes can be manually operated
slow
level of automated suited for complicated processes
fully automated
for safety reasons a very complicatd process plant involving rapid process changes
level of automatiion suited for a process plant where certain process parameters must be maintained for reasons of safety or product quality
semi-automated
Why plants might not be FULLY automated
- Comparison of the automation capital cost relative to on ite manpower costs
- Available of expertise on site to operate a fully automated process plant
- A dependable power supply
Benefit of process control
- Safer operation
- Consistent specification of produced
- Easier to optimise process
- Data history
- Remote operation from site process plant
- Reduced manpower requirements
in “contact” with the process and gives an output that depends on the variable
sensing elements
takes the signal and converts it to a more suitable form for the processing
signal conditioning
takes the output and converts it is a form suitable for presentation (e.g. analogue to digitial converter)
signal processing
the read out
data presentation element
present a numerical value corresponding to the variable being measured
measurement system
require operator to interpret the measurement and take appropriate action
indicators
