SU1661076A1 - Method of storing gas-saturated petroleum in pontoon roof tanks - Google Patents

Abstract

The invention relates to the oil refining and oil producing industries and can be used in the operation of tanks intended for the preparation and storage of crude gas saturated oil. The aim of the invention is to reduce evaporation losses while reducing the filling time and increasing the effective volume of the tank. In the flow of crude gas-saturated oil entering the tank during the period of filling it up to the liquid level below the height preventing oil degassing, an antifoam additive is supplied. 1 il.

Description

The invention relates to the oil and petrochemical industry and can be used in the operation of tanks for the preparation and storage of oil.

The aim of the invention is to reduce evaporation losses while reducing the filling time and increasing the effective volume of the tank. The implementation of the proposed method allows, during the operation of tanks with a pontoon, to provide conditions under which oil foaming is prevented, and consequently, the sinking of the pontoon by pouring oil onto the pontoon due to foaming, increase the filling rate and reduce evaporation losses during filling.

The drawing shows a tank with a pontoon for storing crude gas-saturated oil,

The tank 1 for crude gas-saturated oil contains a pontoon 2, a dispenser 3, a metering pump 4, a tank 5 for antifoam additive, a pipeline 6 for supplying gas-saturated crude oil, a signal buoy 7 placed in one of the racks 8, and a switch 9 electrically associated with the pump.

The method of storing gas-saturated oil is as follows.

Gas-saturated froth oil is fed to an empty tank 1 with a pontoon 2 through a dispensing pipe 3. Simultaneously with the oil using the metering pump 4 from the tank 5 Through pipe 6 serves to the oil inlet into the tank antifoam additive (for example, type SKTN). At the same time between the walls of the pontoon and reservoir 1 there is a gas that is formed as a result of oil degassing, but without foaming. The surface of the pontoon remains dry. Upon reaching the level of oil corresponding to the height h, excluding the possibility of razgazirovasl

with

oh oh

about

4 o

neither the oil entering the reservoir 1, and therefore the foaming, the signal buoy 7, located in one of their guiding pillars 8 of the pontoon 2, touches the switch 9 located at height h and turns it off. In this case, the dosing pump 4 is turned off and the supply of the antifoam additive to the tank is stopped. When the oil level in the reserve reaches, the height h through the signal buoy 7 is restarted. The pump 4 is activated.

In this case, the height excluding the oil degassing in the tank is considered to be the height h, consisting of the three component heights hi, ha and Of (see) li 5 ° TI-I h2 3, where hi is the height from the bottom of the reg-rvoir to the jet axis;

Ii2 is the height of the maximum outlet of the buried jet (near the tank wall) of the surface;

L3 is the height providing the pressure of the liquid column equal to the pressure of saturated oil vapor.

P2 (3, 4-1) .R0

where a is the coefficient of the structure (a — 0.08 for a round jet; and 0.09–0.12 for a spray jet);

x is the distance or exit cut of the angle to a given point to the reservoir wall;

Ro is the radius of the pumping head or the supply pipeline. The height is calculated according to the Formula.

P wg

h3 -;

Ri

where PS is the vapor pressure of oil;

Pr is the pressure in the gas zone of the reservoir (above the surface of the liquid;

PH is the density of oil.

In the raw material tanks, they try to maintain the maximum possible level (they only leave a reserve for possible uneven pumping and pumping of liquid from the reservoir), as it is necessary to maintain a significant (2–4 m) water level (water cushion). Therefore, most of the time, the level of oil in the tank exceeds the height, which prevents the oil entering it from degassing. And only because of the uneven pumping and pumping of oil (approximately 5-20% of the working time) does the level of oil in the reservoir fall below the height precluding the degassing of the oil. At these moments, partial oil degassing occurs, accompanied by foaming, which often leads to

drowning pontoons, oil overflows in the form of foam from the tank, etc. In the case of using an unsinkable pontoon, oil in the form of a foam enters and evaporates from its surface, thereby

the efficiency of use of the pontoon is significantly reduced.

The proposed method does not limit the filling capacity of the tank depending on the height of the inlet (level)

fluid in it. The tank can be filled with any capacity without fear of foaming it by supplying an antifoam additive at low levels of oil and by using large take-off levels (levels to prevent oil from being injected into the tank, which reduces evaporation.

Claims (2)

Invention Formula  . The method of storing gas oil in a pontoon tank, including filling, sludge and dispensing, characterized in that, in order to reduce evaporation losses while reducing the filling time and increasing the net volume, in the filling process to the level at which oil degassing is excluded, simultaneously with supplying i-saturated oil, foam is quenched by introducing antifoam additive into the volume of oil. 2. A method according to claim 1, characterized by heme, that the level at which oil degassing is excluded is defined by the formula h П1 + П2 + ПЗ, m where hi is the height from the bottom of the tank to the axis of the infusion jet, m; P2 - the height of the maximum output of the submerged jet (near the tank wall) to the surface, m From the height of the oil column pressure equal to the saturated vapor pressure, m