EP4733247A1

EP4733247A1 - System for detecting overflow of fluids in a storage tank and method therefor

Info

Publication number: EP4733247A1
Application number: EP24208391.3A
Authority: EP
Inventors: Walter LOBUE DOS SANTOS; Fernando FERREIRA LUIZ; Robson RATZKA GUEDES
Original assignee: Yara International ASA
Current assignee: Yara International ASA
Priority date: 2024-10-23
Filing date: 2024-10-23
Publication date: 2026-04-29
Also published as: WO2026087551A1

Abstract

System for detecting overflow of a fluid in a storage tank (15) comprising an an inlet pipe (14) configured to receive the fluid from a delivery station (11) and in communication with the storage tank (15); an outlet pipe (16) in communication with the storage tank (15) and configured to release vapours and excess fluid rising from the storage tank; and an electric level switch (17) mounted on the outlet pipe (16) and connected to a line (18A), the line (18A) configured to receive vapours and the excess fluid from the outlet pipe and particularly configured for transferring the vapours and excess fluid to a scrubbing reservoir (19A). The electric level switch (17) comprises a central body (34) including a plurality of sensors (34a, 34b) disposed at its centre and is adapted to receive or detect the excess fluid rising in the outlet pipe. The present disclosure further provides a method for detecting overflow of a fluid in a storage tank and the use of the system to perform the method of present disclosure.

Description

TECHNICAL FIELD

The present disclosure relates to the field of control systems for filling fluids in storage tanks. More particularly, the present disclosure relates to a system and method for detecting overflow of fluids in storage tanks, thereby preventing the storage tanks from being overfilled during the loading procedure.

BACKGROUND

A wide variety of fluids such as crude oil, gasoline, diesel, kerosene, acids, alkalis, flammable liquids, and combustible liquids are filled in storage tanks either for storing them for a long period or for transporting them from one place to other. These storage tanks can be industrial process tanks, tank trucks and the like. Tank trucks can be used for the transporting some of these fluids to the desired locations. The loading and unloading of fluids in storage tanks is a common practice performed by the operators daily and well known in the art. These practices can significantly impact the quality and safety of the fluids being stored or transported.
A storage tank overfill occurs when a fluid being stored in a tank exceeds the tank's capacity, causing it to spill out of the tank. Given the hazardous nature of these fluids, overfilling of the storage tanks can result in spills that can pose potential safety risks to the operators. Hazardous material spills of significant quantity during their transport on highways or expressways can be expensive to clean up, causing harm to the environment. Such spills in the environmentally sensitive location pose serious risks.
When loading the storage tanks with fluids, a visual indication may not be possible. As known in the prior art, in some systems overfill probes are installed in the tanks that provide a signal to shut down the delivery pumps when loading is complete. These systems typically comprise a probe that extends downward from the top of the tank. When in operation, the probe will be able to sense the presence of the fuel when it rises to a sensor on the bottom end of the probe. However, these systems are not reliable and could face issues when the probe becomes non-functional either by mishandling by operators or because of equipment failure. This results in the tank to be either underloaded or overfilled.
An example of such a delivery system is illustrated in US20100289654 , which discloses an overfill sensor probe that facilitates the establishment of the maximum fuel level in the tank and is controlled by the extent to which the probe tube extends downward into the tank. Such a system is not useful for filling corrosive fluids as there could be internal damage to the probe material coming in their contact.
US20050139286 provides a modular multi-port manifold and fuel delivery system having a plurality of ports in fluid communication with corresponding compartments of the fuel delivery vehicle. Fuel may be loaded into the compartments through API bottom loading valves. Here, the operator attempts to deliver different products into different compartments as desired and the selection of a desired product permits delivery exclusively from the associated compartment and precludes delivery from products from the other compartments. Accordingly, the compartments are filled with their respective products and the product grade indicators are set that enables the logic controller to identify the content of each compartment of the tank truck. However, with highly corrosive liquids such as acids, oxidants, or hazardous liquids, it is not recommended to load various liquids in the same delivery vehicle.
DE1196575B relates to an overfill protection device for tank trucks with a pump and discharge nozzle with a dispensing hose, consisting of an electrical level switch to be inserted into the container to be filled and an electromagnetic overfill protection valve controlled by it. Overfill protection devices of this type serve the purpose of only filling the container up to a certain level and preventing the liquid from overflowing at the end of the filling process. In this case, level switch is inserted into the container to be filled such that the sensor rod is lowered into the dipstick of the container. This could result in damage to the sensor if the fluid to be filled is of corrosive nature.
In conventional industrial process tanks or tank trucks, to efficiently load the fluids the operator needs to manually determine the amount of fluid to be loaded. Tank overfills can occur in a variety of situations such as during the filling process, due to operator error, equipment failure, or due to problem with the tank having a considerable product residue before loading. Overfilling of hazardous fluids can result in environmental damage, safety hazards, and economic losses, as well as damage to the tank and its associated equipment. To prevent tank overfills, it is important to follow proper procedures, use reliable equipment, and maintain clear communication among the operators and the maintenance process.
Thus, there is a need for a system for detecting overflow of fluids that meets these conditions. There is also a need to have physical indication of appropriate amount of fluid being filled in the storage tank, without interfering with the operator services.

SUMMARY

The present disclosure addresses one or more of the above indicated needs. The disclosure provides an improved system and process for loading fluids in a storage tank.
In one aspect of the present disclosure, a system for detecting overflow of a fluid in a storage tank adapted to hold the fluid is disclosed. The system comprises:

an inlet pipe located downstream of a shutoff valve and a pump, configured to receive the fluid from a delivery station at one end and in communication with the storage tank at other end for filling the fluid therein;
an outlet pipe in communication with the storage tank at one end and configured to release vapours and excess fluid rising from the storage tank at its other end; and
an electric level switch mounted on the outlet pipe towards the end of the outlet pipe releasing the vapours and the excess fluid and connected to a third line at its other end, the third line configured to receive vapours and the excess fluid from the outlet pipe and particularly configured for transferring the vapours and excess fluid to a scrubbing reservoir; wherein the electric level switch comprises a central body including a plurality of sensors disposed at its centre, wherein the electric level switch is adapted to receive or detect the excess fluid rising in the outlet pipe from the storage tank and contacting the sensors.

In an embodiment according to the system of the disclosure, the pump is stopped, and the shutoff valve is closed when the excess fluid rising in an outlet pipe contacts the sensors, thereby halting the inflow of the fluid in the storage tank.
In an embodiment according to the system of the disclosure, the scrubbing reservoir is further connected to a first line in communication with a funnel and/or in communication with a second line in communication with a gutter located below the storage tank, wherein the funnel is adapted to receive the excess fluid from the outlet pipe when disconnected from the storage tank and the gutter is adapted to receive the fluid from the tank and transferring it to the scrubbing reservoir through the second line.
In an embodiment according to the system of the disclosure, the electric level switch further comprises a magnetic head connected to the central body and including a socket therein.
In an embodiment according to the system of the disclosure, an electric circuit is enclosed in the socket of the magnetic head and is in communication with the plurality of sensors and further operably connected to an indicator, optionally through a plurality of cables.
In an embodiment according to the system of the disclosure, the electric circuit is encased in a corrosion protection material selected from epoxy resin and conformal coating, and more preferably an epoxy resin, thereby protecting the electric circuit from corrosion.
In an embodiment according to the system of the disclosure, the indicator emits an output signal when the excess fluid filled in the storage tank rises in the outlet pipe and contacts the sensors.
In an embodiment according to the system of the disclosure, the indicator is a visual indicator comprising a screen for displaying a visual signal and/or wherein the indicator is an alarm that emits an audio signal.
In an embodiment according to the system of the disclosure, the fluid filled in the storage tank is preferably selected from the group consisting of acids, alkalis, bases, and oxidants. In an embodiment according to the system of the disclosure, the acids are selected from but not limited to hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, acetic acid, and chromic acid.
In an embodiment according to the system of the disclosure, the alkalis are selected from but not limited to ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium carbonate.
In an embodiment according to the system of the disclosure, the bases are selected from but not limited to ammonia, copper hydroxide, zinc hydroxide, silver hydroxide, and calcium hydroxide.
In an embodiment according to the system of the disclosure, the oxidants are selected from but not limited to hydrogen peroxide and ozone.
In a further aspect of the present disclosure, a method for detecting overflow of a fluid in a storage tank adapted to hold the fluid, is disclosed. The method comprising:

a. introducing a fluid from a delivery station into the storage tank through an inlet pipe located downstream of a shutoff valve and a pump;
b. filling the storage tank with the fluid;
c. enabling excess fluid in the storage tank to rise in an outlet pipe that is in communication with the storage tank and configured to release vapours and the excess fluid from the storage tank in an electric level switch, wherein the electric level switch is mounted on the outlet pipe and comprises a central body including a plurality of sensors disposed at its centre;
d. emitting an output signal on an indicator when the excess fluid rises in an outlet pipe and contacts the sensors of the electric level switch; and
e. stopping the pump and closing the shutoff valve when the sensors detect the excess fluid, thereby halting the inflow of the fluid in the storage tank.

In an embodiment according to the method of the disclosure, the electric level switch further comprises a magnetic head connected to the central body and including a socket therein.
In an embodiment according to the method of the disclosure, an electric circuit is enclosed in the socket of the magnetic head, the electric circuit is in communication with the plurality of sensors and connected to an indicator through a plurality of cables.
In an embodiment according to the method of the disclosure, the indicator is a visual indicator comprising a screen for displaying visual signal or wherein the indicator is an alarm that emits an audio signal.
In an embodiment according to the method of the disclosure, the method further comprises the step of transferring the vapours and the excess fluid rising from the outlet pipe to a scrubbing reservoir, particularly via a third line connected to the electric level switch.
In an embodiment according to the method of the disclosure, the method further comprises the steps of disconnecting the outlet pipe from the storage tank and transferring the excess fluid from the outlet pipe or from the tank to a scrubbing reservoir, particularly via a funnel and/or via a second line connected to a gutter located below the storage tank.
In an embodiment according to the method of the disclosure, the fluid filled in the storage tank is selected from the group consisting of acids, alkalis, bases, and oxidants.
In an embodiment according to the method of the disclosure, the acids are selected from but not limited to hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, acetic acid, and chromic acid.
In an embodiment according to the method of the disclosure, the alkalis are selected from but not limited to ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium carbonate.
In an embodiment according to the method of the disclosure, the bases are selected from but not limited to ammonia, copper hydroxide, zinc hydroxide, silver hydroxide, and calcium hydroxide.
In an embodiment according to the method of the disclosure, the oxidants are selected from but not limited to hydrogen peroxide and ozone.
Another aspect of the present disclosure provides an use of the system according to the present disclosure to perform the method of the present disclosure.
The advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein it is set forth by way of illustration and example, embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the figures of specific embodiments according to the present disclosure is only given by way of example and is not intended to limit the present explanation, its application or use. In the figures, identical reference numerals refer to the same or similar parts and features.

FIG. 1 shows a preferred embodiment of the disclosure wherein the storage tank is a tank truck.
FIG. 2 shows another embodiment of the disclosure wherein the storage tank is an industrial process tank.
FIG. 3 shows the side view of the electric level switch of the present disclosure.
FIG. 3A shows the top view of the electric circuit enclosed in the socket of the electric level switch.
FIGs. 3B, 3C and 3D show a flanged, a welded and a threaded connection of the electric level switch to the outlet pipe of the storage tank along with details of the sensors.
FIG. 4 shows a perspective view of the electric level switch connected to a visual indicator for displaying a visual signal.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, however, for convenience and completeness, particular terms and their meanings are set forth below.
The articles "a," "an" and "the" are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise. The terms "comprise" and "comprising" are used in the inclusive, open sense, meaning that additional elements may be included. The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements, or method steps. It is not intended to be construed as "consists of only."
The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.
Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described.
All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.
The present disclosure relates to a system for detecting overflow of a fluid in a storage tank resulting in efficient operation while loading, storing, or delivering the fluids to their desired location.
In one aspect of the present disclosure, a system for detecting overflow of a fluid in a storage tank adapted to hold the fluid, is disclosed. The system comprises:

an inlet pipe located downstream of a shutoff valve and a pump, configured to receive the fluid from a delivery station at one end and in communication with the storage tank at other end for filling the fluid therein;
an outlet pipe in communication with the storage tank at one end and configured to release vapours and excess fluid rising from the storage tank at other end; and
an electric level switch mounted on the outlet pipe towards the end of the outlet pipe releasing the vapours and the excess fluid and connected to a line at its other end, said line configured to receive vapours and the excess fluid from the outlet pipe and particularly configured for transferring the vapours and excess fluid to a scrubbing reservoir; wherein the electric level switch comprises a central body including a plurality of sensors disposed at its centre, wherein the electric level switch is adapted to receive or detect the excess fluid rising in the outlet pipe from the storage tank and contacting the sensors.

The storage tank can be selected from, but not limited to, an industrial process tank or a tank truck and is capable of storing a variety of fluids. The term "Industrial Storage Tank" construes to mean a container used for storage of variety of fluids and is employed for industrial purposes. Industrial storage tanks come in different sizes and shapes and could be above the ground tanks or underground tanks. They can be horizontal or vertical, and be made from concrete, stone, fiberglass, steel, or plastic. The term "Tank Truck" refers to a truck with a tank body, suitable for transporting gases or liquids. The term 'Electric Level Switch' refers to an electrical device used to measure the level of fluid and is designed to trigger an output signal when the fluid level in the storage tank reaches a predetermined value.
The inlet pipe and the outlet pipe can be removably attached to the storage tank to create a fluid-gas tight seal. In some embodiments, when the storage tank is a tank truck, the inlet pipe and the outlet pipe can preferably be a flexible hose. In certain embodiments, when the storage tank is an industrial process tank, the inlet pipe and the outlet pipe can preferably be a rigid pipe.
In an embodiment according to the system of the disclosure, the pump is stopped, and the shutoff valve is closed when the excess fluid rising in an outlet pipe contacts the sensors, thereby halting the inflow of the fluid in the storage tank. As known to the skilled person, shut-off valves are known to safely stop or continue the flow of fluids in various applications. Stated differently, in an embodiment according to the system of the disclosure, the system is configured to stop the pump and to close the shutoff valve, when the excess fluid rising in the outlet pipe contacts the sensors, thereby halting the inflow of the fluid in the storage tank. In some embodiments, the system may comprise a control module configured to stop or deactivate the pump and to close the shutoff valve upon the detection of excess fluid rising in the outlet pipe by the sensors in the electric level switch.
In an embodiment according to the system of the disclosure, the scrubbing reservoir is further connected to a first line in communication with a funnel and/or in communication with a second line in communication with a gutter located below the storage tank, wherein the funnel is adapted to receive the excess fluid from the outlet pipe when disconnected from the storage tank and the gutter is adapted to receive the fluid from the tank and transferring it to the scrubbing reservoir through the second line.
In a preferred embodiment, when the fluid to be filled in the storage tank is an acid, the scrubbing reservoir comprises a water based solution to capture the acidic gases by absorbing them. The subsequent vapours emitted from the scrubber and discharged out from the opening contain a low residual amount of the acidic gas that it no longer poses a threat.
The gutter is alternatively referred to as a containment dike and is used to confine leaks, drips, runoff, and spillages of the tank should it spill. In certain embodiments, the gutter can be built around the storage tank.
In an embodiment according to the system of the disclosure, the electric level switch further comprises a magnetic head connected to the central body and including a socket therein.
In an embodiment according to the system of the disclosure, an electric circuit is enclosed in the socket of the magnetic head and is in communication with the plurality of sensors and further operably connected to an indicator, optionally through a plurality of cables.
The sensors are made of any material that delivers reliable measurement of the flow of the fluids and has a great resistance to the acids, alkalies, bases and oxidants. As known to the skilled person, Tantalum is impermeable to most liquids, especially acids, alkalies, bases and oxidants, making it ideal for use in an electric level switch. In preferable embodiments of the present disclosure, the plurality of sensors are made of Tantalum.
In an embodiment according to the system of the disclosure, the electric circuit is encased in a corrosion protection material thereby protecting the electric circuit from corrosion.
A variety of corrosion protection materials as known to the skilled person can be used in the present disclosure. In a preferred embodiment, the corrosion protection material is selected from epoxy resin and conformal coating, and more preferably an epoxy resin. The epoxy resin is a thermosetting polymer that hardens when mixed with a catalyst. Due to high adhesion, hardness, mechanical strength, and resistance to solvents and chemicals, the epoxy resin protects the electric circuit from impacts, vibrations, chemicals and moisture. It maintains stable properties between -40 to 120°C. The resin encases the entire electric circuit, exposing only the powers supply terminals. A conformal coating is a thin protective coating applied to the electric circuit and provides corrosion resistance by creating a barrier to the penetration of corrosive gases or fluids.
In an embodiment according to the system of the disclosure, the indicator emits an output signal when the excess fluid filled in the storage tank rises in the outlet pipe and contacts the sensors.
In an embodiment according to the system of the disclosure, the indicator is a visual indicator comprising a screen for displaying a visual signal and/or wherein the indicator is an alarm that emits an audio signal.
The visual and audio signal, alone or in combination, alert the operator to effectively monitor fluid level in the storage tank and to detect overfill events, ensuring immediate response when critical threshold is reached. In the preferred embodiment, the visual signal can be in the form of a light. In certain embodiments, the system may provide transmission of a potential alarm to a remote site with a wired or a wireless signal. Once deployed at a remote location, the operator can use a web or mobile application to manage the fluid level.
In an embodiment according to the system of the disclosure, the fluid filled in the storage tank is particularly selected from the group consisting of acids, alkalis, bases, and oxidants. In an embodiment according to the system of the disclosure, the acids are selected from but not limited to hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, acetic acid, and chromic acid.
In an embodiment according to the system of the disclosure, the alkalis are selected from but not limited to ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium carbonate.
In an embodiment according to the system of the disclosure, the bases are selected from but not limited to ammonia, copper hydroxide, zinc hydroxide, silver hydroxide, and calcium hydroxide.
In an embodiment according to the system of the disclosure, the oxidants are selected from but not limited to hydrogen peroxide and ozone.
In a further aspect of the present disclosure, a method for detecting overflow of a fluid in a storage tank adapted to hold the fluid, is disclosed. The method comprising:

In an embodiment according to the method of the disclosure, the electric level switch further comprises a magnetic head connected to the central body and including a socket therein.
In an embodiment according to the method of the disclosure, an electric circuit is enclosed in the socket of the magnetic head, the electric circuit is in communication with the plurality of sensors and connected to an indicator through a plurality of cables.
In an embodiment according to the method of the disclosure, the indicator is a visual indicator comprising a screen for displaying visual signal or wherein the indicator is an alarm that emits an audio signal.
The visual and audio signal, alone or in combination, alert the operator to effectively monitor fluid level in the storage tank and to detect overfill events, ensuring immediate response when critical threshold is reached. In the preferred embodiment, the visual signal can be in the form of a light. In certain embodiments, the system may provide transmission of a potential alarm to a remote site with a wired or a wireless signal. Once deployed at a remote location, the operator can use the web or a mobile application to manage the fluid level.
In an embodiment according to the method of the disclosure, the method further comprises the step of transferring the vapours and the excess fluid rising from the outlet pipe to a scrubbing reservoir, particularly via a third line connected to the electric level switch.
In an embodiment according to the method of the disclosure, the method further comprises the steps of disconnecting the outlet pipe from the storage tank and transferring the excess fluid from the outlet pipe or from the tank to a scrubbing reservoir, particularly via a funnel and/or via the second line connected to a gutter located below the storage tank.
In an embodiment according to the method of the disclosure, the fluid filled in the storage tank is preferably selected from the group consisting of acids, alkalis, bases, and oxidants. In an embodiment according to the method of the disclosure, the acids are selected from but not limited to hydrochloric acid, sulphuric acid, nitric acid, phosphoric acid, acetic acid, and chromic acid.
In an embodiment according to the method of the disclosure, the alkalis are selected from but not limited to ammonium hydroxide, potassium hydroxide, sodium hydroxide and sodium carbonate.
In an embodiment according to the method of the disclosure, the bases are selected from but not limited to ammonia, copper hydroxide, zinc hydroxide, silver hydroxide, and calcium hydroxide.
In an embodiment according to the method of the disclosure, the oxidants are selected from but not limited to hydrogen peroxide and ozone.
Another aspect of the present disclosure provides an use of the system according to the present disclosure to perform the method of the present disclosure.
In a preferred embodiment of the disclosure, FIG. 1 illustrates a system for detecting overflow of a fluid in a tank truck (10). The tank truck comprising a storage tank (15) is adapted to hold the fluid, such as an acid, which is to be transported to the desired location. The delivery station (11), filled with the desired fluid, is connected to a pump (12) and a shutoff valve (13). The inlet pipe (14), preferably in the form of flexible hose, is located downstream of the shutoff valve (13) and is configured to receive the fluid from the delivery station at one end. The inlet pipe (14) is in communication with the storage tank (15) at the other end for filling the fluid therein, to form a fluid-gas tight seal. An outlet pipe (16), preferably in the form of a flexible hose, is in communication with the storage tank (15) at one end and is configured to release vapours and excess fluid rising from the storage tank at its other end. During the loading procedure, the operator manually connects the inlet pipe (14) and the outlet pipe to a storage tank (15) of the tank truck and aligns the fluid in the delivery station (11) to set a predetermined value of the fluid to be filled. This sets the loading procedure in action. An electric level switch (17) is mounted on the outlet pipe (16) towards the end of the outlet pipe releasing the vapours and the excess fluid and connected to a line (18A) at its other end. The line 18A is configured to receive vapours and the excess fluid from the outlet pipe and particularly configured for transferring the vapours and excess fluid to a scrubbing reservoir (19A). The scrubbing reservoir (19A) is further connected to a line 18B in communication with a funnel (16A) and/or in communication with a line 18C in communication with a gutter located below the storage tank. The funnel (16A) is adapted to receive the excess fluid from the outlet pipe (16) when disconnected from the storage tank (15) and the gutter is adapted to receive the fluid from the tank and transferring it to the scrubbing reservoir (19A) through line 18C.
In another embodiment of the diclosure, Fig. 2 illustrates a system for detecting overflow of a fluid in an industrial process tank (20). The industrial process tank comprises a storage tank (15) that is adapted to hold the fluid, such as an acid. During loading of the industrial process tank, operator manually connects an inlet pipe (not shown) to the opening (22) of the storage tank (15). The inlet pipe, preferably a rigid pipe, is located downstream of a shutoff valve and a pump (not shown) and is configured to receive the desired fluid from a delivery station (not shown). An outlet pipe (16), preferably a rigid pipe, is in communication with the storage tank (15) at one end and is configured to release vapours and excess fluid rising from the fluid filled in the storage tank at other end. The vapours rising from the fluid filled in the storage tank (15) are directed to upper section of the tank and, in turn, to the outlet pipe that is connected to the electric level switch (17) and the line (18). The electric level switch is mounted on the same outlet pipe (16), as there is no resistance to the fluid or vapour outflow. Downstream of the electric level switch (17), the line (18) transfers the vapours rising from the fluid filled in the storage tank (15), particularly acidic gases, to a scrubbing reservoir (not shown).
Referring now to Fig. 3 , the side view of the electric level switch (17) of the present disclosure can be elaborated. The electric level switch may be powered by a 24-volt source and comprises a central body (34) including two sensors (34a, 34b) disposed at its centre.
These sensors as seen in Figs. 3b-3d , are connected to two electrodes (35a and 35b) at opposite positions on the piece and are adapted to receive or detect the excess fluid rising in the outlet pipe from the storage tank of Figs. 1 and 2 . The electric level switch (17) further comprises a magnetic head (31) connected to the central body (34) and including a socket (32) therein. An electric circuit (32a) is enclosed in the socket (32) of the magnetic head (31), the electric circuit is in communication with the sensors (34a, 34b) and further operably connected to an indicator, optionally through a plurality of cables. In a preferred embodiment, the electric circuit is connected to a visual indicator (43) through a plurality of cables (44), as seen in Fig. 4 .
The diameter of the pipe (33) between the sensors in a preferable embodiment is approximately 1 inch and can be customized as per requirements. The pipe (33) of the electric level switch is connected to the outlet pipe of Figs. 1 and 2 and can be either flanged (as seen in Fig. 3b ), welded (as seen in Fig. 3c ) or threaded (as seen in Fig. 3d ). The flanged connection provides an ease of use with a stable flange mounting (36). The welded connection is welded directly on the outlet pipe at the interface (37). The threaded connection comprises a plurality of threads (38) that ensure secure connection with the outlet pipe. These connection types of the pipe (33) with the inlet pipe facilitate installation and standardisation according to the industrial process design.
The electric circuit (32a) is encased in a corrosion protection material thereby protecting the electric circuit from premature corrosion. A variety of corrosion protection materials as known to the skilled person can be used in the present disclosure. In a preferred embodiment, the corrosion protection material is an epoxy resin. The resin encases the entire electric circuit, exposing only the three connection terminals (39a) and the conductivity regulator (39b). The connection terminals (39a) include positive powers supply terminal, negative power supply terminal and a digital signal terminal. The regulator (39b) is responsible for ensuring accuracy when detecting the transition from liquid to vapour.
Referring now to Figs. 1-4 , a method for detecing the overflow of the a fluid in a storage tank and the functioning of the electric level switch (17) can be demonstrated. The desired fluid from a delivery station (11) is introduced into the storage tank (15) through an inlet pipe (14) located downstream of a shutoff valve (13) and a pump (12). When the fluid to be filled in the storage tank (15) exceeds the predetermined value, the excess fluid in the storage tank is enabled to rise inside the outlet pipe (16) and to contact with the electric level switch, particularly the sensors. The sensors (34a and 34b) enclosed in the electric level switch are adapted to receive or detect the excess fluid rising in the outlet pipe from the storage tank (15). An electric circuit (32a) enclosed in the socket (32) of the magnetic head (31) is connected to an indicator optionally through a plurality of cables. In a preferred embodiment of Fig 4 , the indicator is a visual indicator (43) connected to the electric circuit through a plurality of cables (44) and is adapted to emit an output signal when the excess fluid rises in the outlet pipe (16) and contacts the sensors. The visual indicator comprises a screen (43a) for displaying the output signal. More particularly, the visual indicator emits light as an output signal, thereby visually indicating to immediately stop the loading procedure. At the same time, the pump and the shutoff valve are closed, such as via a control module (not shown), to stop the inflow of the fluid into the storage tank (15).
As the fluid in the storage tank exceeds the predetermined value, the outlet pipe transfers the rising vapours and the excess fluid to a scrubbing reservoir (19A), via line 18A. The outlet pipe is further disconnected from the storage tank (15) and the excess fluid from the outlet pipe (16) is transferred to a scrubbing reservoir (19A), particularly via a funnel (16A) and/or via a line (18C) connected to a gutter located below the storage tank (15).
The system according to the present disclosure offers several advantages. The system allows efficient detection of the overflow of fluids in storage tanks thereby enabling the operators to efficiently load desired fluids. The system is effective in preventing environmental accidents, bodily harm to the operators, material damage and minimizes potentially hazardous spills. This system is suitable for use with a tank truck, an industrial process tank or any other storage tank for filling any type of fluid. The examples of fluids commonly filled in the tank truck include crude oil, gasoline, diesel, kerosene, acids, flammable liquids, and combustible liquids. More preferably, the system of present disclosure is suitable for filling acids, alkalis, bases, and oxidants in storage tanks. The electric level switch used in the system, is preferably installed vertically, and works with precision and offers functional reliability. Moreover, the system of present disclosure provides a physical indication of appropriate amount of fluid being filled in the storage tank without interfering with the operator's service. In case of the industrial process tank, the electric level switch is installed vertically in the same upper gas drain duct or the oulet pipe. The advantage of this equipment is that the process has no internal interference or resistance within the ducts, preventing any encrustation or deposition of chemical materials.

EXAMPLE

The system of the present disclosure was tested in the laboratory. The laboratory setup is in accordance with the Fig. 4 described herein. In the laboratory on a test bench, the fluid is introduced directly in the electric level switch (17) via a sample tube (41). The sensors (not shown) enclosed in the central body (34) are adapted to receive or detect the fluid entering from the sample tube. An electric circuit (32a) enclosed in the magnetic head (31) is connected to a visual indicator (43) through a plurality of cables (44), the visual indicator is adapted to emit an output signal when the excess fluid contacts the sensors. The visual indicator comprises a screen (43a) for displaying the output signal. When the fluid comes in contact with the sensors, the visual indicator displays an output signal, in the form of a light, thereby indicating to stop the process of introducing the fluid in the electric level switch.
While the preferred embodiments of the present disclosure have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims.

Claims

A system for detecting overflow of a fluid in a storage tank (15) adapted to hold the fluid, the system comprising:
- an inlet pipe (14) located downstream of a shutoff valve (13) and a pump (12), configured to receive the fluid from a delivery station (11) at one end and in communication with the storage tank (15) at other end for filling the fluid therein;

- an outlet pipe (16) in communication with the storage tank (15) at one end and configured to release vapours and excess fluid rising from the storage tank at other end; and

- an electric level switch (17) mounted on the outlet pipe (16) towards the end of the outlet pipe (16) releasing the vapours and the excess fluid and connected to a line (18A) at other end, the line (18A) configured to receive vapours and the excess fluid from the outlet pipe and particularly configured for transferring the vapours and excess fluid to a scrubbing reservoir (19A); wherein the electric level switch (17) comprises a central body (34) including a plurality of sensors (34a, 34b) disposed at its centre, wherein the electric level switch is adapted to receive or detect the excess fluid rising in the outlet pipe from the storage tank and contacting the sensors.
The system according to claim 1, wherein the pump is stopped and the shutoff valve (13) is closed when the excess fluid rising in an outlet pipe (16) contacts the sensors, thereby halting the inflow of the fluid in the storage tank (15).
The system according to claim 1 or 2, wherein the scrubbing reservoir (19A) is further connected to a first line (18B) in communication with a funnel (16A) and/or in communication with a second line (18C) in communication with a gutter located below the storage tank, wherein the funnel (16A) is adapted to receive the excess fluid from the outlet pipe (16) when disconnected from the storage tank (15) and the gutter is adapted to receive the fluid from the tank and transferring it to the scrubbing reservoir (19A) through the second line (18C).
The system according to any one of claims 1 to 3, wherein the electric level switch (17) further comprises a magnetic head (31) connected to the central body (34) and including a socket (32) therein.
The system according to claim 4, wherein an electric circuit (32a) is enclosed in the socket (32) of the magnetic head (31) and is in communication with the plurality of sensors (34a, 34b) and further operably connected to an indicator, optionally through a plurality of cables.
The system according to claim 5, wherein the electric circuit (32a) is encased in a corrosion protection material selected from epoxy resin and conformal coating, and more preferably an epoxy resin, thereby protecting the electric circuit from corrosion.
The system according to claim 5, wherein the indicator emits an output signal when the excess fluid filled in the storage tank (15) rises in the outlet pipe (16) and contacts the sensors.
The system according to any one of claims 5 to 7, wherein the indicator is a visual indicator (43) comprising a screen (43a) for displaying a visual signal and/or wherein the indicator is an alarm that emits an audio signal.
A method for detecting overflow of a fluid in a storage tank (15) adapted to hold the fluid, the method comprising:
a. introducing a fluid from a delivery station (11) into the storage tank (15) through an inlet pipe (14) located downstream of a shutoff valve (13) and a pump (12);

b. filling the storage tank (15) with the fluid;

c. enabling excess fluid in the storage tank (15) to rise in an outlet pipe (16) that is in communication with the storage tank and configured to release vapours and the excess fluid from the storage tank in an electric level switch (17), wherein the electric level switch is mounted on the outlet pipe (16) and comprises a central body (34) including a plurality of sensors (34a, 34b) disposed at its centre;

d. emitting an output signal on or by an indicator when the excess fluid rises in an outlet pipe (16) and contacts the sensors (34a, 34b) of the electric level switch (17); and

e. stopping the pump and closing the shutoff valve when the sensors detect the excess fluid, thereby halting the inflow of the fluid in the storage tank.
The method according to claim 9, wherein the electric level switch (17) further comprises a magnetic head (31) connected to the central body (34) and including a socket (32) therein.
The method according to claim 10, wherein an electric circuit (32a) is enclosed in the socket (32) of the magnetic head (31), the electric circuit is in communication with the plurality of sensors (34a, 34b) and connected to an indicator through a plurality of cables.
The method according to any one of claims 9 to 11, wherein the indicator is a visual indicator (43) comprising a screen (43a) for displaying visual signal or wherein the indicator is an alarm that emits an audio signal.
The method according to any one of claims 9 to 12, wherein the method further comprises the steps of disconnecting the outlet pipe (16) from the storage tank (15) and transferring the excess fluid from the outlet pipe (16) or from the tank (15) to a scrubbing reservoir (19A), particularly via a funnel (16A) and/or via a second line (18C) connected to a gutter located below the storage tank (15).
The method according to claims 9 to 13, wherein the fluid filled in the storage tank is selected from the group consisting of acids, alkalis, bases, and oxidants.
Use of the system according to claims 1 to 8 to perform the method according to claims 9 to 14.