Process Measurement, Dynamics & Control Assignment
The P&ID in Figure 1 shows the equipment needed to perform an experiment to determine the effect that Temperature, Flow rate and Concentration of NaOH have on cleaning a consumer healthcare product from inside sections of pipe work (S001 and S002). The purpose of the experimental rig is to investigate the potential for cost savings on a large-scale process by optimising the standard operating cleaning procedure.
To set up the experiment, first the sections of pipe work S001 and S002 are removed from the rig. The pipes are then filled with product before being replaced in situ. The properties of the product are that it is an opaque, viscous liquid that is soluble in water.
T001 contains pure water and is kept at a constant level using a float valve. It provides the water for T002 and for rinsing the system after cleaning.
T002 is used to make up different concentrations of NaOH in water. To increase the bulk temperature of this cleaning mixture, the fluid is pumped using P001 through the heat exchanger X001 and re-circulates back into T002, by-passing the test sections by opening valve V004.
To perform an experiment, the heated cleaning fluid is passed through either S001 or S002 before going back into either; the feed tank (T002), the collection tank (T003) or to the drain depending on the mode of operation required by the operator.
a) Specify all the instrumentation and control loops that you think are necessary for the operator to perform this experiment and gather as much useful data as possible. You should state the reasons for your choice of instrumentation.
b) Using the information provided in Table 1, re-draw the P&ID including the instruments you have selected taking care to ensure appropriate placement of the devices. The diagram should drawn to an A3 size using an appropriate software package such as Microsoft Visio and be of a professional standard.
Instructions
Your report should be no more than 3 pages and in addition should include your finalised P&ID as an appendix. The contents of the report should focus on the justification of your choice of instrument and their locations/ control loop pairings.
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First Letter
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Succeeding Letters
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Measured or
Initiating Variable
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Modifier
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Read Out or
Passive Function
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Output Function
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Modifier
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A
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Analysis
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Alarm
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B
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Burner or Combustion
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User's Choice
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User's Choice
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User's Choice
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C
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User's Choice (e.g. Conductivity)
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Control
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D
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User's Choice (e.g. Density)
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Differential
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E
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Voltage or emf
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Sensor or Primary Element
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F
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Flow rate
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Ratio/Fraction
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G
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User's Choice
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Sight Glass or Viewing Device
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H
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Hand
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High
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I
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Electrical Current
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Indicate
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J
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Power
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Scan
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K
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Time or Schedule
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Rate of Change
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Control Station
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L
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Level
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Light (Pilot)
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Low
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M
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User's Choice (e.g. Moisture/Humidity)
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Momentary
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Middle
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N
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User's Choice
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User's Choice
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User's Choice
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User's Choice
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O
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User's Choice
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Orifice or restriction
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P
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Pressure or Vacuum
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Point (Test)
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Q
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Quantity (e.g. Conc./Conductivity)
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Integrate/Totalise
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R
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Radiation
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Record or Print
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S
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Speed or Frequency
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Safety
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Switch
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T
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Temperature
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Transmit
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U
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Multivariable
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Multifunction
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Multifunction
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Multifunction
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V
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Vibration or Mechanical Analysis
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Valve or Damper
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W
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Weight or Force
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Well or Pocket
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X
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Unclassified
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X-axis
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Unclassified
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Unclassified
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Unclassified
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Y
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Event, State or Presence
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Y-axis
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Relay, Compute or Convert
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Z
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Position or Dimension
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Z-axis
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Driver, Actuator or Other
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