STUDY OF LOW VOLTAGE WATER MIST INDUCTION

CHARGING:WATER PRESSURE EFFECT

SITI NUR’AIN BT AJIS [25109]

INTRODUCTION

•Water mist system is the water that formed into small droplet water through nozzle in desire pressure.

•The smaller the water droplet, the higher the ability of water spray effectiveness.

•Small droplets of water mist charging can be created when the water is sprayed at high pressure.

PROBLEM STATEMENT

• A lot of water is used to produce high water pressure.• It wasted a lot of water and cost.• Some researched are done to upgrade water mist

system.• Electrostatic charging method is used to approach this

problem.• The voltage will applied into the liquid and formed

very small particle of water.• Water pressure is used as the parameter to investigate

the effect of water pressure on the water mist system.

OBJECTIVES

• To study the water pressure effect on water mist.• To study the effect of electrostatic charging

towards water mist.• To study the relationship between the

electrode-nozzle distance with current, voltage and charge-to-mass.• To study the water mist separation region.

LITERATURE REVIEW

Advantages of using water mist system.•The amount of water used in water mist is

very less compared using sprinkler system.

•The water mist system has very small size of water droplet than sprinkler system.

•Water mist system low in cost compared to agent gaseous system.

Water mist system Sprinkler system

Electrostatic charging methods

Classified into direct charging and indirect charging.

I.Direct charging method• For example, conduction charging method.• Known as ‘charging by contact’.• Connect the charged object to the neutral

object.• Risk in leaking current from nozzle to the

water tank as the nozzle configuration directly applied with voltage.

II. Indirect charging method• For example, induction charging method.• Does not apply contact between material

to the charged object.• More safer than conduction charging

method.

COMPARISON OF DIRECT AND INDIRECT CHARGING METHOD

Direct charging Indirect charging

METHODOLOGY

I. Water mist separation region• To clarify the electrostatic atomization

mechanism.• Because in the induction charging, the

generation time of drop must surpass the charge relaxation time

II. Electrostatic atomization• Investigate the relationship between

electrode configuration and water mist separation region.

Experiment Apparatus for Water Mist Separation Region.

Experiment Parameter

Apparatus Setup for Electrostatic Atomization

Experiment

Flow chart of experiment

PROJECT ANALYSIS & DISCUSSION

Water mist separation region• Higher nozzle-wire

distance, d, the higher it resistance value.

• The water mist separation region for 0.05MPa is between 1 - 11 mm.

• The water mist separation region for 0.10MPa is between 1 - 15 mm.

• Water mist exceed its water surface tension limit and caused water drop become smaller.

Current versus Electrode-nozzle Distance for 0.05 Mpa and 0.10 Mpa

Charge-to-mass of Water Mist• Slightly increased and

decreased value of charge-to-mass.

• At point 13mm fro 0.05MPa, charge-to-mass rapidly change.

• Due to the relationship between current and electrode-nozzle distance

• Consumed that chorona discharged was determined when spray angle of water mist touched the ring electrode.

CONCLUSION

• The experiment is conducted in two different water pressure, 0.05MPa and 0.10MPa. • Induction method was choose as the

charging method.• In this project, low voltage is applied rather

than high voltage. • From the observation , low voltage produce

unstable current flow.

RECOMMENDATION

• The experiment should be conduct using high voltage. The highest voltage will produce fine water droplet than the low voltage.• Used more high pressure to get better

result.• Additional subtopic such as investigate

the water pressure effect on spray characteristic of electrostatic-induction water mist charging should be suggested.

THANK YOU