WO2010067185A1

WO2010067185A1 - Self-sealing draining unit for separating immiscible fluids of different densities

Info

Publication number: WO2010067185A1
Application number: PCT/IB2009/007709
Authority: WO
Inventors: Jorge Enrique Forero Sanabria; Javier Diaz Sierra; Jorge Enrique Veira Ibarra; Victor Julio Echeverria Restrepo
Original assignee: Ecopetrol S.A.
Priority date: 2008-12-12
Filing date: 2009-12-03
Publication date: 2010-06-17
Also published as: CO6170067A1

Abstract

The present invention relates to a self-sealing draining unit for separating immiscible fluids of different densities, amongst which are water and hydrocarbons, requiring minimal human supervision of the hydrocarbon-storage tanks and with greater efficiency, which reduces the loss of valuable liquid. The drainage unit is characterized in that it comprises an outer cylinder (1), an inlet nozzle (2), an outlet nozzle (3), an upper seal (4a), a lower seal (4b), float guides (5a and 5b), an upper float (6a) and a lower float (6b), a cover (8), drains (13a and 13b), an upper flotation chamber (15a), a lower flotation chamber (15b) and a flow-regulation chamber (17).

Description

SELF-SEALING DRAINAGE UNIT FOR SEPARATION OF IMMISCIBLE FLUIDS OF DIFFERENT DENSITY

TECHNICAL FIELD OF THE INVENTION

Light refined storage tanks, such as gasoline, gasoline, diesel and medium crude, decant water that cannot be separated easily into production plants. To drain the water contained in these tanks, the manual visual method is used, which requires a person dedicated to visually verify when the phase changes from water to hydrocarbon.

The self-sealing drainage unit object of the present invention performs the separation of two immiscible liquids of different density, including water and hydrocarbons, requiring minimal human supervision of the hydrocarbon storage tanks and with greater efficiency, which reduces The loss of valuable liquid.

BACKGROUND OF THE INVENTION

In the state of the art there are different types of valves or self-sealing drainage units for the process of decanting liquids of different density. There are commercial settling valves to drain a wide variety of liquids of different specific gravities, these valves are semi-automatic and generally, specific for a limited range of operating densities.

Readicional to the aforementioned disadvantages, said valves do not have an adequate response to the hydrodynamics of the drainage process, which causes a poor closure thereof and require high complexity in their operation when presenting a high number of mechanical elements. For him On the contrary, the present application relates to a system for draining fluids of different specific gravity that requires low supervision by its operation, which presents lower losses of hydrocarbon by drag and has a low cost of manufacturing, installation, operation and maintenance.

U.S. patent application 5,918,622 discloses a valve for separating immiscible liquids of different specific gravity. This includes a container containing a liquid receiving chamber and a device in the lower part of said container for the exit of the liquid of greater specific gravity. In this valve, the float does not always perform the seal, due to the turbulence generated at the exit of the higher density fluid. Another limitation of this valve is that it has two pressure equilibrium points, which increases the possibility of failure in the operation.

On the other hand, the U.S. patent 5,935,427 refers to a system for draining liquid from a storage tank. Specifically, this invention relates to a system by which it is possible to remove liquids, generally in the aqueous phase, which precipitate to the bottom of the liquid product storage tanks. This patent uses a sensor that controls two valves that are operated electrically and / or pneumatically. The unit reported in this document has a greater complexity in the installation and operation, since the calibration of the float system is difficult because the valve is inside a storage tank.

Another request related to this type of valves is the Colombian patent 98-07453, whose invention consists of a portable applicator for delivering material capable of flowing from a container. The system disclosed in this patent application does not apply to the operating conditions of the present application, especially since the valve described in said document is portable, not dedicated and requires actuation by the operator. The invention contained in the application CO 97-69199 consists of a liquid supply system comprising a cylinder that has an inlet to receive the liquid, an outlet to dispense the liquid, a piston that is movably coupled to the cylinder to exert pressure on the liquid when said piston is actuated, and a compression spring connected to said piston and to the housing. The equipment presented in the aforementioned document is not suitable for the separation conditions of liquids of different specific gravity because it basically consists of a mechanical level control system that only supplies a liquid from a full container.

Finally, we mention the Colombian patent 316,858 aimed at a process and apparatus for separating liquids in an alkylation settler. The invention claimed in the present document consists of a container that defines a separation zone with three portions to separate a mixture comprising a heavier liquid and a lighter liquid. Said invention is not used for hydrocarbon-water separation conditions, but in alkylation processes. In addition, the alkylation processes separate sulfuric acid from light hydrocarbons, whose density difference is noticeable and is usually carried out in non-continuous processes.

In view of the separation equipment reported in the state of the art and its deficiencies, there is a need for autonomous and economic valves, which require a minimum of human control, which do not need external energy application, which are very efficient and that allow the separation in line of large quantities of fluids, even flows greater than 4 m ³ per minute.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be understood in a better way by means of the figures, where each of the elements that make up the unit of unit are shown. self-sealing drain for the separation of immiscible fluids, which it is desired to protect. In addition, the figures show the reference numbers assigned to the elements that make up said device.

Figure. 1: This figure corresponds to a view of a central section of the self-sealing unit of the present invention, showing all the internal and external elements that comprise it.

Figure. 2: This figure corresponds to several perspective views of the self-sealing unit of the present invention.

Figure. 3: This figure corresponds to the general location of the self-sealing unit of the present invention within the drainage process of the hydrocarbon storage tank.

DETAILED DESCRIPTION OF THE INVENTION

The self-sealing drainage unit for separation of immiscible fluids of different density object of the present application, is a useful equipment for the drainage of the separated water in the storage tanks of light and crude unrefined hydrocarbons, which is used to recover the heaviest of two immiscible liquids that has been decanted in a storage container.

The applicability and versatility of this equipment is focused on eliminating problems that arise during the drainage or manual separation of one of the immiscible phases. Its basic advantages are: to minimize the intervention of the operator in the drainage process, avoiding the loss of product due to human error, especially when there is little difference in color between the phases; constitute a security element in effluent discharge systems reducing and / or eliminating pollution problems; and require Low attention, service and maintenance, which substantially reduces operating costs.

The self-sealing unit of the present invention consists of the following parts: an outer cylinder (1), an inlet nozzle (2), an outlet nozzle (3), an upper seal (4a), a lower seal (4b), float guides (5a and 5b), an upper float (6a), a lower float (6b), a cover (8), a rod guide (9), a rod (10), a flow stabilizing grid ( 11), a vent or pressure regulator (12), drains (13a and 13b), a steering wheel of the rod (14), an upper flotation chamber (15a), a lower flotation chamber (15b), a regulating valve of the upper float (16a), a lower float regulator valve (16b) and a flow regulation chamber (17).

The floats (6a and 6b) of the invention can be solid or hollow. Preferably, said floats are hollow in order to allow the modification of their apparent densities, to adjust them by introducing inert materials through the regulating valves (16a and 16b), which modify the flotation properties according to the fluid system in which the self-sealing unit will operate. This allows the production of self-sealing units in series, the reduction of manufacturing costs and the adaptation of said unit to any fluid separation system.

Additionally, the valve of the present application comprises two floats to optimize the security in the seal and decrease the volume of hydrocarbon lost. In addition to the above, the configuration of the float guide (5a and 5b) allows the orientation of the floats (6a and 6b) to be directed towards the seals (4a and 4b), as will be described later.

In a preferred embodiment, the upper (4a) and lower (4b) seals are interchangeable and are made of soft metallic or polymeric materials. Operating system

The self-sealing drain unit for fluid separation operates based on the principle of buoyancy force given by the difference in the specific gravity of the float with the immiscible phases. The heavy phase enters the flow regulation chamber (17) through the inlet nozzle (2), then the fluid passes through a flow stabilizing grid (11) and enters the upper flotation chamber (15a ), where the upper float (6a) is raised allowing the passage of fluid into the lower flotation chamber (15b) through the upper seal (4a). When fluid passes to the lower flotation chamber (15b), the lower float (6b) is also raised, allowing the exit of the highest density liquid through the outlet nozzle (3).

The drainage process continues until a change in the specific gravity of the fluid lowers the upper float (6a) to the first upper seal (4a), closing it automatically and preventing the passage of fluid. Likewise, the lower float (6b) descends when the liquid contained in the lower flotation chamber (15b) is drained through the outlet nozzle (3).

The presence of two floats (6a and 6b) in the self-sealing unit reduces the risk of leaks because in case of failures in the first upper seal (4a), the lower float (6b) will act by closing the lower seal (4b), avoiding the passage of the light fluid to the collection tank of the first fluid. Additionally, the existence of these two floats allows to extend the range of effective operation of the self-sealing unit, using floats of different specific density, with which it is possible to control the small changes in density that a fluid experiences due to external factors, including changes in temperature and system pressure. The self-sealing unit of the present invention has its main application in the drainage of the heavy phase of a storage system or tank. Although its applications in the oil industry are mainly related to the drainage of water in oil storage tanks, refined and / or intermediate products, the self-sealing valve of the invention can be used in typical two-phase systems, such as hydrocarbon-water, naphtha-water, diesel-water, light distillates-water and gasoline-aviation-water.

However, the application of the self-sealing drainage unit for separation should be avoided when high viscosity fluids are present, such as breasts or heavy crudes, when there is a high concentration of solids present in the mixture, when high temperatures occur intermittence or when the specific gravity of the two liquids is very close.

Thus, the self-sealing drain unit can be used for any separation operation within the limits of its capacity and available pressure.

For the start-up of the system, once it has been installed, the flow of the fluid through the inlet nozzle (2) to the self-sealing unit is allowed. The air in the system is released through the vent valve (12) located in the lid (8). Subsequently, the balancing valves connected to the drains (13a and 13b) are opened to equalize pressures on both sides of the floats (6a and 6b) and during the transit of fluid through the unit said valves are closed. This allows the floats (6a and 6b) to ascend in the heavy fluid. Then the flow is allowed through the outlet nozzle (3) to the drain to allow the start of the discharge of the heavy phase. The drainage period is maintained until the light phase enters the upper flotation chamber (15a), allowing the upper float (6a) to descend and make the first seal to restrict the flow through the unit. The lower float (6b) maintains its open position while the sealing efficiency of the upper float (6a) is optimal. In case there is a light phase leak from the upper chamber (15a) to the lower chamber (15b), the lower float (6b) will act by sealing the unit. Once the floats (6a) and / or (6b) have reached their location in the seals (4a and 4b), the flow stops. To finish the drainage stage, the inlet valve is closed and the system is unoccupied by the drains (13a and 13b). In the next drain shift, the procedure is repeated taking into account that all valves start in the closed position.

The optimum performance of the self-sealing unit of the invention is ensured with the presence of a flow regulation chamber (17) installed inside the valve, prior to the flotation chambers (15a and 15b). This camera allows to counteract the turbulence effect that could be created on the two floats (6a and 6b), which would limit their efficiency.

Finally, the self-sealing unit system has a cover (8) that allows quick and easy access for the maintenance of the internal elements of the equipment. The placement of the lid (8) in the upper part of the self-sealing unit is versatile because it has a quick opening system defined by a rod (10), which has a guide (9) for its movement and a steering wheel ( 14) which allows to rotate the rod (10) in an easy, versatile and safe way, in order to have access to the interior of the self-sealing unit and to carry out the proper maintenance.

However, in Figure 3, the best way to incorporate the self-sealing unit of the invention is illustrated in a process of draining storage tanks. In it the drainage of the storage tank (20) is directly connects to the nozzle (2) of the self-sealing unit and the drainage system of the area (30) is connected to the nozzle (3) of the same unit.

Thus, the installation of the self-sealing drainage unit must be carried out on the drainage line of the storage tank (20). For this, it must be taken into account that the dimensions of the inlet pipe must not be smaller than those of the entrance to the self-sealing drain unit, which has a diameter that is in the range of 10.16 a 15.24 centimeters (4 to 6 inches). Additionally, in the outlet connection a blocking valve must be installed, with a hole diameter similar to that of the connection flange. Any section of pipe installed downstream of the self-sealing drain unit must be as short and straight as possible. Also, it is recommended to enable an alternate exit point to perform the normal drainage operation.

Claims

1. A self-sealing drain unit for the separation of immiscible fluids of different density, characterized in that it comprises an outer cylinder (1), an inlet nozzle (2), an outlet nozzle (3), an upper seal (4a), a lower seal (4b), float guides (5a and 5b), an upper float (6a), a lower float (6b), a cover (8), drains (13a and 13b), an upper flotation chamber ( 15a), a lower flotation chamber (15b) and a flow regulation chamber (17).

2. The self-sealing drain unit of claim 1, characterized in that the flow regulation chamber (17) is located inside the valve, prior to the flotation chambers (15a and 15b) and allows to counteract the effect of turbulence of the inlet fluid to the self-sealing unit.

3. The self-sealing drain unit of claim 1, characterized in that the upper and lower floats (6a, 6b) and the upper and lower seals (4a, 4b) are arranged inside the upper and lower flotation chambers (15a , 15b), specifically the seals (4a, 4b) are located in the lower part of each of said floats (6a, 6b).

4. The self-sealing drain unit of claim 3, characterized in that the upper (4a) and lower (4b) seals are interchangeable.

5. The self-sealing drain unit of claim 4, characterized in that said seals (4a, 4b) are made of soft metallic or polymeric materials.

6. The self-sealing drain unit of claims 3 to 5, characterized in that the floats (6a and 6b) can be solid or hollow.

7. The self-sealing drain unit of claim 6, characterized in that said floats (6a, 6b) are preferably hollow to allow the modification of their apparent densities.

8. The self-sealing drain unit of claim 7, characterized in that the floats (6a, 6b) further comprise regulating valves (16a, 16b).

9. The self-sealing drain unit of claim 8, characterized in that said floats (6a, 6b) are filled with inert materials, through the regulating valves (16a and 16b).

10. The self-sealing drain unit of claim 1, characterized in that it further comprises a flow stabilizing grid (11).

11. The self-sealing drain unit of claim 1, characterized in that the cover (8) comprises a vent valve (12) that allows the release of air from the self-sealing unit.

12. The self-sealing drain unit of claim 11, characterized in that said cover (8) also comprises a rod (10), a rod guide (9) and a rod flywheel (14).

13. The self-sealing drain unit of claim 1, characterized in that the drains (13a, 13b) are connected to a series of balancing valves to equalize the pressures on both sides of the floats (6a and 6b).