CLEANING METHOD FOR TANKS INTENDED FOR OIL AND OIL PRODUCTS STORAGE AND TRANSPORTATION AT NEGATIVE VALUES OF AMBIENT AIR TEMPERATURE Russian patent published in 2015 - IPC B08B9/93 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to in particular, to processes of collection, accumulation, storage and transportation of oil and oil products in tanks of different purpose and design, and may be used for year-round cleaning of oil tanks, mainly in winter period, at negative values of ambient air temperature, from deposits generated at the inner surface of tanks. Cleaning of tanks includes heating of the tank by a heat carrier, delivery of washing out agent, dilution and stirring of bottom sediments, discharge and transportation of diluted bottom sediments to the processing stage. At that heating of the inner tank volume and bottom deposits up to positive temperature values and maintenance of positive temperature values within the whole cleaning process is carried out by delivery of pressurized water steam using a steam generator while washing out, dilution and stirring of bottom sediments is made with use of remote-controlled robot-aided guns equipped with video surveillance and lighting system placed inside the tank through the lower process hatches. Discharge of diluted bottom sediments is made by pumps installed at remote-controlled mobile units, which are also placed inside the tank through the lower process hatches. Washing out and transportation is made by the washing out agent at temperature that depends on ambient air temperature up to 310°C under pressure of 1.0-10.0 MPa. Washing of the tank head, walls and bottom is made by orbital washing heads placed in the tank head hatches to which delivery of the washing out agent is switched. Heating of the process equipment placed under framed and tent structures, the structures and pipelines used for delivery of the heat carrier for the tank heating, delivery and discharge of the washing out agent, transportation of diluted deposits for the processing stage is made through the steam line by delivery of pressurized water steam. When the low explosive limit is exceeded inert gas is delivered to the tank automatically.

EFFECT: development of safe and effective cleaning of oil tanks from sediments and further processing of the above sediments at negative values of ambient air temperature.

2 dwg