FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
AUTOMATIC DRAINING SYSTEM FOR FUEL-WATER SEPARATORS IN VEHICLES
FLEETGUARD FILTERS PRIVATE LIMITED
an Indian Company
of Kirloskar House, 100, Anand Park,
Aundh, Pune - 411 007,
Maharashtra, India.
Inventors: Tilak Vidyadhar Madhav Khandkar Arun Ganesh
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF DISCLOSURE
The present disclosure relates to draining systems in fuel-water separators.
BACKGROUND
Diesel fuel is easily contaminated by water because diesel absorbs water more than gasoline does. It is undesirable for water in fuel to be drawn into a diesel engine fuel system as the system relies on diesel for lubrication of the moving parts. For this reason many diesel vehicles are provided with a gadget called a fuel-water separator that separates water from fuel. The water separator is usually housed along with a contaminant filter.
Water accumulates at the bottom of the separator from which it must be drained at regular intervals to ensure continued efficient operation of the engine. A majority of fuel-water separators need to be manually drained by turning a drain valve also referred to as 'petcock' to empty water from the collection chamber of the separator. In order to dispose water properly, one has to wait until clean diesel starts flowing after all the water has drained out. This is a major disadvantage of this mechanism since the only way to determine whether all the water has drained out is to wait until clean diesel flows out resulting in loss of fuel.
Many fuel-water separators contain a water sensor which sends a signal to the engine control unit or directly to the driver via a lamp on the dashboard if the water reaches a predetermined 'warning' level. Also, water can be drained only when the vehicle is stationary. Drivers often overlook and neglect to drain water especially while they are driving. If water gets into a moving part which requires constant

lubrication, for instance, an injector valve, it will cause overheating and unnecessary wear of the part.
Another disadvantage is the location of fuel-water separators. Typically the fuel-water separators are placed at locations which are difficult to reach, thereby making the operation of the drain valve very cumbersome.
Hence there is a need for a system which can drain water from the fuel-water separator at regular intervals without manual intervention. Further there is a need for a system which can prevent loss of fuel while draining water from the fuel-water separator. There is also a need for a system which can be suitably located in the vehicle for ease of operation of the drain valve.
OBJECTS
Some of the objects of the present disclosure are aimed to ameliorate one or more problems of the prior art or to at least provide a useful alternative and are listed herein below.
An object of the system of the present disclosure is to drain water from fuel-water separators without manual intervention.
Another object of the system of the present disclosure is to drain water from fuel-water separators at regular intervals.
Yet another object of the system of the present disclosure is to prevent loss of fuel while draining water from fuel-water separators.

Still another object of the system of the present disclosure is to enable ease of operation of drain valves irrespective of the location of fuel-water separators.
Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present disclosure, an automatic draining system for a fuel-water separator in a vehicle, wherein the system comprises: a first sensing electrode disposed within the fuel-water separator, the first sensing electrode adapted to detect a pre-determined high level of water within the fuel-water separator and generate a corresponding first logic signal; a second sensing electrode disposed within the fuel-water separator at a pre-determined position below the first sensing electrode, the second sensing electrode adapted to detect a pre-determined low level of water within the fuel-water separator and generate a corresponding second logic signal; a drain valve operatively coupled to the fuel-water separator, the drain valve adapted to partially drain water accumulated within the fuel-water separator; and an electric circuit communicating with the first and second sensing electrodes, the electric circuit adapted to open the drain valve in response to the first logic signal to commence draining of water from the fuel-water separator, the electric circuit further adapted to close the drain valve in response to the second logic signal to cease draining of water while retaining a limited quantity of water within the fuel-water separator.

Typically, the first sensing electrode is a three terminal HIGH-LOW level sensing resistive electrode wherein parallel resistances are embedded across the sensing electrode points to enable sensing of open wire faults.
Typically, the second sensing electrode is a three terminal HIGH-LOW level sensing resistive electrode wherein parallel resistances are embedded across the sensing electrode points to enable sensing of open wire faults.
Typically, the first logic signal is HIGH signal.
Typically, the second logic signal is LOW signal.
Typically, the drain valve is a 'peak and hold' type solenoid valve.
Typically, the electric circuit is at least one of a Pulse Width Modulation (PWM) circuit and a coil power hold circuit.
Additionally, the electric circuit comprises a plurality of power switching components coupled in an AND'ed arrangement, wherein each of the power switching components comprises at least one relay and at least one high power transistor.
Additionally, the automatic draining system further comprises a manual override mechanism for manually operating the drain valve to drain water.
DETAILED DESCRIPTION
The automatic draining system of the present disclosure will now be described with reference to the embodiments. The embodiment does not limit the scope and

ambit of the disclosure. The description relates purely to the examples and preferred embodiment of the disclosed method and its suggested applications.
The automatic draining system herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known parameters and processing techniques are omitted so as to not unnecessarily obscure the embodiment herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiment herein may be practiced and to further enable those of skill in the art to practice the embodiment herein. Accordingly, the examples should not be construed as limiting the scope of the embodiment herein.
The automatic draining system of the present disclosure comprises an automatic draining arrangement for draining water accumulated in fuel-water separators. The automatic draining system comprises at least two sensing electrodes positioned at different heights inside the fuel-water separator for sensing the level of the medium (water / diesel / mixture of emulsified water and diesel) inside the fuel-water separator, a drain valve for draining water out of the fuel-water separator and an electrical circuit for actuating the drain valve based on the water level sensed by the electrodes.
In accordance with one embodiment, a first sensing electrode is positioned at a higher height than a second sensing electrode whereby a difference in the level of water sensed by the electrodes is used for actuation of the drain valve. The first sensing electrode generates a logic HIGH signal when the level of water reaches a tip of the first electrode. Upon detecting the logic HIGH signal, the electrical circuit opens the drain valve to start draining of water out of the fuel-water

separator. The second sensing electrode generates a logic LOW signal when the water level reduces and reaches a tip of the second electrode. Upon detecting the logic LOW signal, the electrical circuit closes the drain valve to stop draining of water. The entire content of water in the fuel-water separator is not drained out. A small quantity of water is retained, thereby preventing loss of fuel.
In accordance with one embodiment, an air passage is created by lifting a vent disk in the fuel-water separator. In accordance with another embodiment, the air passage is created by lifting a valve shaft in the fuel-water separator upwards. When the water level is sensed, water starts draining only when the air passage is opened up. As a result a continuous flow of water is maintained during draining.
In accordance with one embodiment, the drain valve of the automatic draining system is a 'peak and hold' type solenoid valve driven by a Pulse Width Modulation (PWM) circuit to drain out water. The solenoid valve opens and closes at predetermined intervals controlled by the PWM circuit to drain out water.
In accordance with another embodiment, the electrical circuit comprises a coil power hold module. The module intermittently supplies power to the coil of the drain valve wherein the holding force is achieved with minimal power and current usage.
In accordance with the present disclosure, the automatic draining system as described herein above is independent of the location of the system with reference to a fuel pump in the vehicle. The automatic draining system of the present disclosure can be located on either a pressure side or a suction side of a fuel pump thereby making the system very versatile.

Optionally, the automatic draining system of the present disclosure comprises a manual override mechanism for manually operating the drain valve to drain out water in the event of any emergency situation.
The key features of the automatic draining system are listed herein below but not limited to:
• The automatic draining system can be placed at a location convenient for operation in a vehicle.
• The drain valve is a fail safe operation valve which trips under no power condition arresting the drain of the diesel.
• The valve is powered by a double safety 'ANDed' arrangement of power switching components increasing safety against failures.
• The power switching components include at least one relay and at least one high power transistor. The relay provides galvanic isolation between power supply and coil of the drain valve. It is switched ON at zero voltage and switched OFF at zero current thereby increasing the life of the relay. Furthermore, galvanic isolation provides defence against load dump pulses.
• A three terminal HIGH-LOW level sensing resistive electrode is used which enables state-based draining instead of time-based draining. As a result, water can be drained without loss of diesel irrespective of the location of the fuel-water separator.
• Two level sensing allows the electrode faults to be detected even if the electrodes are contaminated with microbial growth.
• Parallel resistances are embedded across the sensing electrode points to allow sensing of open wire faults.

• The automatic draining system of the present disclosure can be adopted across
vehicles because the design of the system includes:
■ On the fly tuning of 12V / 24V battery operated vehicles. No separate zero calibration is required.
■ Full functionality - Ignition / Acceleration / OFF type of ignition switch, cowl variants.
■ Indication of water status via LED or Lamp based instrument clusters.
1 Intelligence to detect, annunciate and reset possible field faults. No separate third party tool is required for fault annunciation.
■ Optimum thermal and sleep mode design.
• The drain valve of the automatic draining system utilizes a peak and hold type
solenoid valve driven by PWM technique to accommodate both 12V and 24V
power supplies.
The automatic draining system of the present disclosure includes safety features listed herein below:
• The system will operate only when engine is stopped.
• If the engine is cranked during draining operation, the supply coil is cut-off and draining stops immediately.
Thus the automatic draining system of the present disclosure enables draining of water from fuel-water separators at regular intervals without manual intervention, at the same time preventing loss of fuel while draining water. Furthermore, the automatic draining system of the present disclosure can be located on either a pressure side or a suction side of a fuel pump thereby making the system very versatile.

TECHNICAL ADVANCEMENTS AND ECONOMIC SIGNIFICANCE
The technical advancements offered by the system and method of the present disclosure include the realization of:
• draining water from the fuel water separator without manual intervention;
• draining water from the fuel water separator at regular intervals;
• preventing loss of fuel while draining water from the water fuel separator; and
• enabling ease of operation of the valve irrespective of the location of the fuel water separator in cases of manual overriding.
Throughout this specification the word "comprise", or variations such as "comprises"
or "comprising", will be understood to imply the inclusion of a stated element, integer
or step, or group of elements, integers or steps, but not
the exclusion of any other element, integer or step, or group of elements, integers or
steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements, as the use may be in one of the embodiments to achieve one or more of the desired objects or results.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the invention, unless there is a statement in the specification specific to the contrary.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within me meaning an£ range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We Claim:
1) An automatic draining system for a fuel-water separator in a vehicle, said
system comprising:
• a first sensing electrode disposed within the fuel-water separator, said first sensing electrode adapted to detect a pre-determined high level of water within the fuel-water separator and generate a corresponding first logic signal;
• a second sensing electrode disposed within the fuel-water separator at a predetermined position below said first sensing electrode, said second sensing electrode adapted to detect a pre-determined low level of water within the fuel-water separator and generate a corresponding second logic signal;
• a drain valve operatively coupled to the fuel-water separator, said drain valve adapted to partially drain water accumulated within the fuel-water separator; and
• an electric circuit communicating with said first and second sensing electrodes, said electric circuit adapted to open said drain valve in response to said first logic signal to commence draining of water from the fuel-water separator, said electric circuit further adapted to close said drain valve in response to said second logic signal to cease draining of water while retaining a pre-determined quantity of water within the fuel-water separator.

2) The automatic draining system as claimed in claim 1, wherein said first sensing electrode is a three terminal HIGH-LOW level sensing resistive electrode wherein parallel resistances are embedded across the sensing electrode points to enable sensing of open wire faults.
3) The automatic draining system as claimed in claim 1, wherein said second sensing electrode is a three terminal HIGH-LOW level sensing resistive

electrode wherein parallel resistances are embedded across the sensing electrode points to enable sensing of open wire faults.
4) The automatic draining system as claimed in claim 1, wherein said first logic signal is HIGH signal.
5) The automatic draining system as claimed in claim 1, wherein said second logic signal is LOW signal.
*
6) The automatic draining system as claimed in claim 1, wherein said drain valve is a 'peak and hold' type solenoid valve.
7) The automatic draining system as claimed in claim 1, wherein said electric circuit is at least one of a Pulse Width Modulation (PWM) circuit and a coil power hold circuit.
8) The automatic draining system as claimed in claim 1, wherein said electric circuit comprises a plurality of power switching components coupled in an AND'ed arrangement, each of said power switching components comprising at least one relay and at least one high power transistor.
9) The automatic draining system as claimed in claim 1, further comprising a manual override mechanism for manually operating the drain valve to drain water.