FORM 2
THE PATENT ACT, 1970
(39of 1970)
&
THE PATENTES RULES, 2005
COMPLETE SPECIFICATION (See section 10, rule 13)
1. TITLE OF THE INVENTION
"Heating System For Melting Solid Biofuel In A Fuel Tank"
2. APPLICANT
(a) Name : MAHINDRA & MAHINDRA LIMITED
(b) Nationality : Indian Company registered under the provisions
of the Companies Act, 1956 (c) Address : R&D Center, Automotive Sector,
89, M.I.D.C, Satpur, NASHIK - 422 007 Maharashtra State, India
3. PREAMBLE OF THE DESCRIPTION
COMPLETE
The following specification particularly
describes the invention and the manner in which it is to be performed.

Heating System For Melting Solid Biofuel In A Fuel Tank
Field of invention
The present invention relates to a heating system employed in the fuel tank of an automotive vehicle running on biofuel, for example, biodiesel, and more particularly, the present invention relates to a heating system for melting solid biofuel in a fuel tank.
Background of the invention
During cold weather conditions and due to poor freezing point, biofuel, for example, biodiesel in a fuel tank starts freezing and gradually solidifies. Even at 10 C, waxing starts occurring in the fuel tank. As the solidified/waxed biodiesel restricts the fuel flow, vehicles do not start - especially during morning hours when the ambient temperature is low. Therefore, it is necessary to liquidize the biofuel to make it available for suction from the fuel tank.
The use of the heater is restricted to usage of 100% biodiesel only, since flash point of the biodiesel is around 170° C, which is much higher compared to the 40° C of regular diesel. For automotive applications, instant heating is essential while considering the safety aspects of the fuel tank.
Accordingly, there exist a need to provide a heating unit for melting the solidified biodiesel in the fuel tank which overcomes the abovementioned drawbacks.
Object of the invention

An object of the present invention is to melt waxed/solidified biodiesel in the tank and make it free to flow so that the biodiesel is available for suction.
Another object of the invention is to provide a circuit that regulates temperature of the heating unit in the fuel tank and maintains that safety aspects are satisfied.
Yet another object of the present invention is to optimize heat transfer to melt waxed/solidified biodiesel in the tank for ensuring safe and optimum heat
distribution.
Still another object of the present invention is to provide a sensor and its independent mounting for sensing fuel temperature near the heater.
Further object of the present invention is to provide a cost efficient, compact and highly versatile heating solution that can be mounted on almost all biodiesel vehicles with minimum modification of auto component parts.
Brief description of the drawings
The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
Figure 1 shows a front view of a heating system for melting solid biofuel in a fuel tank of the automobile, in accordance with the present invention;
Figure 2 shows front and side view of an outer design of a cover of heating system of figure 1; and

Figure 3 shows front view a glow plug with the cover of the heating system of figure 1.
Detailed description of the invention
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring to figure 1, there is shown a heating system (100) for melting solid biofuel in a fuel tank of an automobile, in accordance with the present invention. The heating system (100) includes a heater unit (50), a sensor mounting tube (60) and a temperature control circuit (70) configured in the fuel tank (80) of the automobile.
The heater unit (50) is positioned in close proximity to a fuel suction strainer (72) attached to a fuel suction line (74) of the fuel tank (80). The heater unit (50) includes an elongated hollow cover member (20) having a first open end (12) and a second closed end (14). As shown in front view and a side view as seen from RHS of the elongated hollow cover member (20) in figure 2, the elongated hollow cover member (20) is configured with grooves (16) on outer surface thereof.
In an embodiment, the elongated hollow cover member (20) is made of stainless steel. The stainless steel material provides better resistance to corrosive nature of biodiesel.

The heating unit (50) further includes at least one glow-plug (30) positioned in the elongated hollow cover member (20). The glow plug (30) is capable of receiving electrical power supply from a power unit (42). As an automotive fuel, biodiesel has a poor heat conductivity coefficient and a high flash point of about 170°c. Since the heat from the glow-plug (30) is concentrated at the tip only, it is required to distribute it evenly along a surface. This function is executed by the stainless steel elongated hollow cover member (20). The grooves (16) on the stainless steel elongated hollow cover member (20) ensure maximum heat transfer by increase in surface area. The glow-plug (30) is an easily available automotive part that runs on 12V battery power and is cheaper, due to which it has been incorporated in the present invention.
Furthermore, the heating unit (20) includes a hollow cylindrical shaft (40) having a top end (32) affixed to the fuel tank (80) and a bottom end (34) affixed to the first open end (12) of the elongated hollow cover member (20). In an embodiment, the elongated hollow cover member (20) is joined to a hollow cylindrical shaft (40) of suitable length by a threaded joint or by a simple press-fit mechanism. The hollow cylindrical shaft (40) prevents direct contact of the fuel with the electrical power supply to the glow-plug (30) and also helps to adjust the heating depth.
The hollow cylindrical shaft (40) is mounted onto a fuel tank (80) using appropriate fixtures. Specifically, an outer thread cut is provided on the cylindrical hollow shaft (40) to facilitate mounting onto the fuel tank (80) by using a washer-nut arrangement therebetween.
Figure 3 shows a sectional view of the elongated hollow cover member (20) including the glow-plug (30). In an embodiment, the glow-plug (30) is either threaded into or attached by press fit into the elongated hollow cover member (20). Specifically, one end of the glow-plug (30) is connected to supply from the temperature controller circuit (70) and the other end is connected to the heating point. The temperature is

concentrated around the tip of the glow plug (30) which is evenly distributed into the frozen fuel by the elongated hollow cover member (20). The temperature attained by glow-plug (30) is as high as 300° to 400° C which can prove very dangerous if not controlled. Hence, the temperature sensor (52) takes into account the fuel temperature at the closest point near the heater unit (50) and provides feedback to the temperature controller circuit (70), which keeps the heater temperature within safe specified limits.
The sensor mounting tube (60) is configured onto the fuel tank (80) wall to hold the temperature sensor (52) thereon. In an embodiment, the sensor mounting tube (60) is made of stainless steel and the temperature sensor (52) is a NTC thermistor temperature sensor.
The temperature control circuit (80) provided for controlling the power unit (42) supplying electrical power supply to the glow plug (30). Specifically, the electrical power supply to the glow plug (30) is controlled by the temperature control circuit (80) based on the input from the temperature sensor (52).
In preferred embodiment, the present invention is specifically to be used for applications involving B100 i.e. 100% pure biodiesel and not for blends. The biodiesel used can be of any feedstock i.e. Jatropha Curcas, Rapeseed, Karanje, Pongamia, Soya, Palm etc provided that it meets ASTM/BIS standards.
Advantages of the invention
1. The heater system (100) greatly improves the cold start ability of a vehicle running on B100.
2. The heater system (100) is rugged, compact and easily mountable.

3. No major changes have to be done on the vehicle to incorporate the heater system (100) therein.
4. The heating system (100) is highly cost effective.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim
1. A heating system for melting solid biofuel in a fuel tank, the heating
system comprising:
a heater unit positioned in close proximity to a fuel suction strainer attached to a fuel suction line of the fuel tank, the heater unit having,
an elongated hollow cover member having a first open end and a second closed end, the elongated hollow cover member configured with grooves on outer surface thereof;
at least one glow-plug positioned in the elongated hollow cover member, the glow plug capable of receiving electrical power supply from a power unit, and
a hollow cylindrical shaft having a top end affixed to the fuel tank and a bottom end affixed to the first open end of the elongated hollow cover member, wherein the hollow cylindrical shaft prevents direct contact of the fuel with the electrical power supply to the glow-plug;
a sensor mounting tube configured onto the fuel tank wall to hold the temperature sensor thereon; and
a temperature control circuit for controlling the power unit supplying electrical power supply to the glow plug, wherein electrical power supply to the heater unit is controlled by the temperature control circuit based on the input from the temperature sensor.
2. The heating system for heating frozen biofuel in a fuel tank as claimed in
claim 1, wherein one end of the glow-plug is connected to supply from the
temperature controller circuit and the other end is a tip of the glow plug which is a
heating point.

3. The heating system for heating frozen biofuel in a fuel tank as claimed in claim 1, wherein temperature is concentrated around the tip of the glow plug which is evenly distributed into the frozen fuel by the elongated hollow cover member.