RU2443483C2 - Method of washing out tank bottom sediment - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to washing out of bottom sediment and may be used in oil industry. Bottom sediment is washed out by oil jet fed via wash-out device arranged at tank bottom. Said device is rotated by fed oil and equipped with rotation speed pickup. Shut-off valves control unit and shut-off valves are designed to vary oil feed to wash-out device.

EFFECT: higher efficiency, reduced electric power consumption.

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Description

The invention relates to devices for erosion of bottom sediments formed at the bottom of vertical tanks with oil and oil products, as well as for mixing oil and oil products to prevent the formation of deposits, and can be used in the oil industry.

It is known "Device for the formation of a rotating fan ring jet of liquid" (No. 2253516), which uses the pressure of the liquid supplied to the tank for erosion of bottom sediments.

The disadvantage of this design and all designs that use the pressure of the liquid of the tank to be filled is that the erosion of bottom sediments occurs only at the time of filling. In practice, erosion of bottom sediments is more important when emptying the reservoir to remove sediment from it into the pipeline.

The well-known "Method of cleaning the tank from bottom sediments and a device for its implementation" (No. 2196062).

The disadvantage is the decrease in the efficiency of erosion of bottom sediments with increasing diameter of the tank.

It is known "Device for erosion of bottom sediments in a tank with oil and oil products" (No. 2220766 prototype).

The disadvantage of this design is the presence of movable joints seals in the tank wall, the repair of which is impossible without decommissioning the tank.

The disadvantage is the decrease in the efficiency of erosion of bottom sediments with increasing diameter of the tank.

The disadvantage is the placement of the electric motor on the tank wall.

The disadvantage is the need to turn off the device when the floating roof reaches a certain safe level, below which the operation of the device is prohibited due to the drift of the floating roof caused by the jet of the device.

The disadvantage of all of the above devices is that the erosion of bottom sediments is carried out without taking into account the quantity, quality and location of bottom sediments. In particular, the prototype device rotates from lock to lock; when the device is turned off and on again, the rotation continues in the same direction, although with the device turned off, the number and location of bottom sediments could change.

The purpose of the invention is the elimination of these disadvantages.

This problem is solved by using a stream of oil supplied to separate erosion devices located on the bottom of the tank for erosion of bottom sediments. In this case, the engine and the pump supplying oil are located outside the tank wall. Oil is taken from the zone without bottom sediments, and the supply to the tank to the erosion devices occurs through separate pipelines, each of which is configured to adjust the oil supply. At the ends of the pipelines, devices are installed to change the direction of the jet of supplied oil. A device for changing the direction of the jet is made to rotate due to the pressure of the supplied oil (is not the subject of the invention). It can either be a hydraulic motor, or jet throwback can be used.

The rotation resistance of the erosion device varies depending on the density of the bottom sediments. A rotation speed sensor is installed on each washout device, the signal from which enters the control unit of the stop valves. The rotation speeds of each device are analyzed depending on the number of simultaneously working devices and their location inside the tank.

The regulation of the flow of oil to various erosion devices is carried out depending on the rotation speed of the erosion device of bottom sediments, i.e. on the quantity and quality of bottom sediments, and the relative position of the erosion devices and the drainage device, to prevent the occurrence of additional loads on the drainage device.

The most effective use of this method on tanks with a high grillage (publication number 2009106195). In this case, all intake and pressure pipelines are located in the space between the grillage and the ground level, outside the tank and do not interfere with erosion of bottom sediments, and are available for monitoring and maintenance. In the same space are the rotation mechanisms of erosion devices with rotation speed sensors.

The use of this invention will allow:

1) constantly maintain tank capacity at the design level;

2) effectively erode bottom sediments regardless of the diameter of the tank;

3) effectively erode bottom sediments at the lowest level of oil spill;

4) reduce the energy consumption of erosion of bottom sediments due to the supply of power to a given point in the tank with minimal losses;

5) to increase the safety of operation of the tank by removing the electric motor from the wall of the tank and eliminating the seals of movable joints in the tank wall;

6) repair the units without taking the tank out of service;

7) reduce the cost of operating the tank.

Claims (1)

A method of erosion of bottom sediments, including exposure to a jet of oil supplied through the erosion device located on the bottom of the tank, characterized in that the erosion jet of oil changes direction due to the rotation of the erosion device by the supplied oil, and the oil supply to each erosion device is regulated depending on the rotation speed erosion devices.