Apparatus for treating gas

A wet electrostatic precipitator for treating a gas stream, comprising:

• an electrostatic chamber having an electrostatic chamber inlet through which the gas stream to be treated is conveyed into the electrostatic chamber and an electrostatic chamber outlet through which the treated gas stream is conveyed from the electrostatic chamber, an inner electrode and an outer electrode arranged to produce an electrostatically charged field therebetween when an electrical potential is applied between said inner and outer electrodes, a liquid inlet for conveying liquid into the electrostatic chamber for providing a liquid curtain over an inner surface of the outer electrode, such that particulates in the gas stream become electrically charged when passing through the field and are drawn towards the outer electrode, where the particulates are entrained by the liquid curtain and removed from the gas stream, wherein the inner electrode comprises a conduit through which a purge gas can be conveyed and said inner electrode further comprises at least one opening located towards the electrostatic chamber inlet and arranged to convey the purge gas from the conduit into the electrostatic chamber substantially laterally to the gas stream flowing through the electrostatic chamber;
• and
• a control configured for controlling a flow of purge gas through the conduit of the inner electrode such that in a first condition the purge gas is conveyed through the conduit at a first flow rate to perform at least one of directing the gas stream towards the outer electrode and disrupting the gas stream, and in a second condition the purge gas is conveyed through the conduit at a second higher flow rate for dislodging deposits accumulated in a region of said at least one opening in the inner electrode;
• wherein the control is operatively connected to a sensor for sensing the deposits and when the deposits have exceed a predetermined amount the control is configured to activate the second condition.