|
Electrostatic
Precipitators
De-Tarrer
& De-Oiler - Wet
Features
-
First installed in Australia in 1964.
-
Steam coil heated insulator compartments, optional electric trace heating.
-
Separate spray systems for washing of upper HV support frame and lower alignment
frame.
-
Wire weight discharge electrodes have long life.
-
Cylindrical construction for high pressure applications.
Construction
Features
The De-Tarrer and De-Oiler electrostatic precipitator are similar in construction and detail, the duty only dictating size differences.
The casing enclosing the interior parts is fabricated from steel plate, heavy gauge all for high pressure applications and 5mm thick wall for standard pressure units.
Access doors are provided in the upper and lower casing sections.
Located on top, but on opposite sides of the casing are the insulator compartments housing the high voltage system support insulators. Steam coils are fitted to the compartments to heat the metal and avoid condensation, Alternatively, the compartments may be electrically heat traced. A blanket of insulation, clad with sheeting is fitted to assist in heat retention.
The collecting system consists of a number of steel pipe sections suspended vertically from the tube sheet and seal welded to it. Each pipe is considered as one gas passage. The tube length and diameter are specific to each application.
The high voltage system consists of an individual electrode per collecting tube, suspended from an upper frame and help taut by a weight per electrode. A frame is fitted at the bottom of the field for alignment and stability purposes. The upper frame is fixed to the support beam, which is support by the insulators either side of the casing.
A transformer rectifier to supply the required high voltage is provided and connects to the high voltage discharge system via bus-ducting. The control cubicle for operation of the transformer rectifier is supplied separate for mounting in a convenient switch room.
Principle of Operation
Gas laden with tar and or oil aerosols enter the ESP casing and then pass upwards through the steel tubing. The aerosol enters the influence of the HV discharge system and becomes charged with negative electrodes. The aerosol is then attracted to the positive grounded pipe, agglomerates in the tubes before trickling down the walls fall into the base of the unit. From there, the liquid exits the module through a nozzle on the low side of the sloping base. The HV System is periodically flushed by the spray system. Benefits
Very high collection efficiency of otherwise difficult to collect wet aerosols.
|