Electric dehydrator

Automation of an electric dehydrator with a volume of 160 m3.

Electric dehydrators with a three-row electrode system with a high-voltage power supply OILPRC with an extensive collector system, in the aggregate of their design elements, equipment and automation, are not inferior to the best foreign analogues.

Electric dehydrators are capacitive horizontal devices with elliptical bottoms, internal devices, fittings for inlet and outlet of working media, for a safety valve block, sampling, drainage and sludge removal, steaming and blowing, for installing instrumentation devices, high voltage bushings, with hatches - manholes, overlays for fixing thermal insulation and service platforms.

The most important part in ensuring the smooth and efficient operation of the electric dehydrator is a high-voltage power source. The proposed power supply is specially designed and patented with 100% reactivity. The power of the high-voltage power source is selected based on the electrophysical and physico-chemical properties of the water-oil emulsion and the technological parameters of the process. The power supply is factory filled with oil and sealed, self-cooling and with a top screw cap.

The advantage of high voltage power supplies:

- for electric dehydrators of various volumes and depending on the physical, chemical and electrophysical properties of oil, a wide range of power supplies with a power of 25 is offered; 37.5; fifty; 75; 100 and 150 kVA, which allows limiting one VIP per electric dehydrator, optimizing its design and reducing the cost;
- have 100% reactivity and are not critical to overloads in case of short circuits of the electrodes;
- provide the ability to select the maximum value of the output voltage in a wide range (12; 16.5; 20; 23; 25 kV AC) by using a simple switch;
- distinguished by a reliable design that ensures high tightness of the power supply housing and, as a result, consistently high dielectric properties of transformer oil throughout the entire service life of the high-voltage power supply;
- have a version with output high voltage direct current with a similar possibility of discrete change of its value, which gives additional efficiency to electric dehydrators used at CDU refineries, where a special depth of dehydration and desalting of oil is required;
- vacuum impregnation of windings with oil according to IEC/IEEE design standards;
- well-established production technology using know-how, a factory cycle of rigorous vacuum and pressure tests guarantee long-term operation;
- equipped with all the necessary means to control the temperature, level and pressure of the oil, as well as to heat the latter during stops to maintain its dielectric properties in cold climates.

Electric dehydrators are equipped with high-voltage power supplies. The control of the high-voltage power supply is provided through the local control panel (hereinafter referred to as the LCP).

The LPU is equipped with an anti-condensation heater, switched on locally with a locking button. The LPU is installed in the immediate vicinity of the electric dehydrator and has an explosion-proof design of the Exd category and a degree of protection against external influences IP66. The location of the health facility is selected near the service area of the electric dehydrator, taking into account the convenience of the staff.

Panel indicating devices can be installed on the LPU - an ammeter showing the current at the input of the high-voltage power source and a voltmeter showing the voltage in the output winding of the high-voltage power source. Inside the body of the LPU, current and voltage converters are mounted for transmission to the automation system according to a standardized protocol. Also, the emergency oil level in the transformer and the emergency temperature in the transformer are indicated on the LPU by means of signal lamps.

The operator can control the transformer locally using the "start", "stop" buttons. The "start" and "stop" buttons can be connected both directly to the transformer power control circuit, and to the automation system, which issues the corresponding control signal. For emergency situations, a mushroom button with an "Emergency Stop" lock is provided, which must be connected directly to the transformer power control circuit.

The local automation system (LSA) based on a programmable industrial controller is designed for operational control, management and technological protection of the electric dehydrator, with the functionality of data exchange with external systems using the standardized RS-485 Modbus protocol, visualization, historical trending and event recording.

The automation project contains a minimum list of controlled parameters:

- The presence of a gas cap in the electric dehydrator;
- Pressure, temperature, interfacial level in the electric dehydrator;
- Opening the gate of the transformer enclosure;
- Pressing buttons on the local control panel of the transformer;
- Current, voltage, oil level and temperature in the transformer;
- Availability of operating voltage;
- Transformer status (on/off).

List of control actions:

- Discrete signals to turn on the light and sound alarms;
- Discrete signals for turning on/off the EDG transformer.