PROCESS: TANK WATER FILLING

PROCESS- The Process is the change in the level of the water in the tank. The Input signal is the

flow in the tank, q (m³/s). The Output signal is the height of the water in the tank. Combining this give the process block diagram.

PHYSICAL AND DESIGN PARAMETERS

Height of the Tank : 5 m

Maximum Fill Level : 4 m

Tank Capacity: 90 m³

Pressure Input Signal : 0 – 10 bar

Exit Pipe Restrictance Parameter: s/m2

In flow (m³/s) Liquid level (m)

Q H

Figure: PROCESS BLOCK DIAGRAM

TRANSDUCER- The Transducer does not measure level directly, but measure the pressure, pressure =

density x gravity x head of liquid. The Pressure Measurement Transducer converts the gauge pressure reading (pressure reading to atmospheric) to an equivalent electrical signal (mA).

TRANSDUCER SPECIFICATIONS

Output Signal 4 to 20mA

Span Limit 10 bar

Accuracy Rating ± 0.1% of span

TANK

Height (m) Measurement Height (mA) H Hm

Figure: MEASUREMENT TRANSDUCER

PUMPS- Pumping System Activate when the control input signal Uc, a current in mA applies to a

Pressure Transducer which in turn produces a Pump to run with a variable torque. This will determines the Flow ( m³/s).

Control Input (mA) Flow Out (m³/s)

Uc Qi

Figure: PUMPS BLOCK

By combining the PUMPS – PROCESS – TRANSDUCER BLOCK DIAGRAM, we find that the Process Block Diagram below.

Control Input (mA) In Flow (m³/s) Liquid Level (m) Measuring Height (mA)

Uc Qi H Hm

Figure: COMBINED BLOCK DIAGRAM

PUMPS – PROCESS – TRANSDUCER: THE PROCESS BLOCK

U = Qi Y = H

LIQUID INFLOW: Qi

MEASUREMENT TRANSDUCER

PUMPS

PUMPS TANK PRESSURETRANSDUCER

LIQUID LEVEL AND TANK PROCESS

SYSTEM

LIQUID OUTFLOW: QoLIQUID LEVEL HEIGHT: H