Dangers and Uses of Static Electricity

Static electricity can be dangerous Static electricity can be dangerous! A spark could ignite a flammable gas or liquid.

Dangers with fuelling aircraft As an aircraft flies through the air, it can accumulate a charge of static electricity. If this is not dissipated before fuelling, an electric spark can occur which may ignite fuel vapours. To prevent this, aircraft and fuel pipe are EARTHED using a copper wire Dangers with fuelling aircraft What causes the build up of charge? The moving fuel rubs along the inside of the fuel pipe. Due to the friction the pipe gets charged up as it picks up electrons from the fuel. The pipe gets a negative charge that could lead to a spark.

Explain how connecting a copper wire to the aeroplane and the ground during fuelling can prevent an explosion.

Uses of static electricity: 1. Paint spraying The spray nozzle is connected is connected to the positive terminal of an electrostatic generator. As the paint droplets leave they repel each other and spread out to form a fine cloud of paint. The metal panel to be painted is connected to the negative terminal. The negatively charged metal panel attracts the positively charged paint.

2.Smoke precipitator An electrostatic precipitator is used to prevent the dust and ash produced by coal fired power stations from entering the atmosphere. The ash and dust becomes charged as it passes through the charged grid of wires. The ash and dust is then attracted to the oppositely charged metal plates. When the plates are shaken the accumulated ash and dust falls down to be collected and removed.