Proportional pressure input with on/off controller using Normally Closed Solenoid

Valve

Asequia, Christian PaoloBayeta, Sheena ClaireCimafranca, Emmanuel

Limo, MariettaPalen, Ian Arnold

Patica, Hazel Dawn

INTRODUCTION Objective:

To control the level in a process vessel using an on/off controller connected to a pressure sensor, with a Normally Closed solenoid valve (SOL2) controlling outflow from the vessel.

Overview: The proportional pressure control method in this

exercise consists of a pressure sensor with an output proportional to the pressure exerted on the sensor. The output is sent to an on/off controller that controls a Normally Closed solenoid valve.

Methodology

Turn main power ON and Run

SoftwareSet PSV to 75%

Set Sampling to automatic @ 10s

interval and continuous duration

Setting the on/off

controllerDisturbances

Feed RateEffect of Inlet

and Outlet Flow Rates

Set Point

METHODOLOGY : SETTING ON/OFF CONTROLLER

Set Proportional Band, Integral Time and Derivative Time to 0.

Set Point Value = 200mm Data logging to automatic and 10 s interval Partially Close Drain Valve Begin Data loggingNote the behavior of Sol 2 as level approaches set point

Continue data logging until stable values for magnitude and height are reached.

METHODOLOGY : DISTURBANCES Create New Results Sheet Begin data logging Allow the fluid level oscillations to settle their original values

Finish Data logging Create new results sheet Begin data logging Close the SOL3 valve Allow the fluid level oscillations to settle their original values

Finish Data logging

METHODOLOGY : SET POINT Alter set point to 100mm begin data logging Allow the oscillations in fluid level to reach steady values of magnitude and duration.

Finish Data logging Create a new results sheet Repeat procedure varying the set point to 150mm, 200mm and 300mm.

METHODOLOGY : FEED RATE Create new results sheet begin data logging Change Inlet feed rate by adjusting the pressure regulator on the inlet of the pipe of the apparatus

Allow the oscillations in fluid level to reach steady values of magnitude and duration.

Alter the feed rate. Continue to reduce feed rate until fluid level in the vessel does not return to set point

finish data logging

METHODOLOGY : EFFECT OF INLET AND OUTLET FLOW RATES Decrease the Outflow rate begin data logging Continue logging until the oscillations about the set point value reach stable values.

finish data logging create new results sheet Increase outflow rate repeat procedure 2-4 Return drain valve to a partially closed position

RESULTS AND DISCUSSION:ON/OFF

0 10 20 30 40 50 60 700

50

100

150

200

250Level vs. Time

Level vs. Time

RESULTS AND DISCUSSION:DISTURBANCE(1)

0 10 20 30 40 50 60 70180

185

190

195

200

205

210Disturbance (1)

Level vs. time

RESULTS AND DISCUSSION:DISTURBANCE(2)

0 5 10 15 20 25 30180

190

200

210

220

230

240

250

239

Disturbance (2)

level vs. time

RESULTS AND DISCUSSION:100mm Setpoint

0 20 40 60 80 100 1200

50

100

150

200

250

Set Point (100mm)

level vs. time

RESULTS AND DISCUSSION:150mm Setpoint

0 5 10 15 20 25 300

20

40

60

80

100

120

140

160

180

SetPoint (150mm)

level vs time

RESULTS AND DISCUSSION:Effect of Feed Rate

0 10 20 30 40 50 60 70 800

50

100

150

200

250

Effect of Feed Rate

level vs time