FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Silencer With Heat Exchanger For Vehicles
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Ranganath kumar S.V. & Sangeet H.Kapoor
both Indian Nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following Complete specification particularly describes the invention
and the manner in which it is to be performed.

FIELD OF INVENTION
This invention relates to silencers used in vehicles and more particularly to silencer with heat exchanger for vehicles.
BACKGROUND OF INVENTION
It is important to provide required temperature level for the passenger compartment and faster clearing of mist / frost formed on the wind screen in rainy or winter seasons in an automobile to enhance occupant comfort. This helps in keeping the passenger fresh by avoiding strain and fatigue in long drives. This also helps in preventing the accidents by clearing mist/frost formed on the windscreen to have clear vision. There are many ways by which a vehicle designer provides such comfort in a vehicle/automobile viz., conventional (heating, ventilation and air conditioning) HVAC systems, only AC systems, only heating systems, heat generated through combustion air for heating coolant and air through cabin heat exchanger, heat generated through electric heaters for heating the coolant and air through cabin heat exchangers or a sophisticated semi automatic / fully automatic HVAC system.
Automobile/vehicles are having different types of engines viz. petrol / gasoline, diesel, hybrid, electrical, bio-fuels. All engines heat up rates differ with respect to time and fully depends on the engine efficiency. If engine is more efficient, the heat rejected to coolant will reduce there by the conventional cabin heater efficiency will drop down. In case of petrol/gasoline engines the heat up rate is better but due to improvement in technology for higher engine efficiency, the problem for engine heat up rate started and required some external heat to meet the regulations and better comfort. Especially new generation diesel engines are facing very severely the problem of engine heat up rate and thereby the cabin heater efficiency getting reduced drastically.


Presently it is in practice to bleed the coolant from engine through the upper cooling line and then pumped to the conventional cabin heater (heat exchanger packed in black box placed underneath the dashboard inside the passenger compartment). The coolant from the cabin heater rejects heat to the air and gets comparatively cooled then passes into the suction line connected to the pump.
US 5799632 teaches a heat transfer system for transferring heat for use onboard a vehicle includes a conductor arranged to conduct exhaust gas discharged from an engine of the vehicle along a serpentine path to generate back pressure for transmission to the engine so that heat of exhaust gas flowing along the serpentine path is maximized. The heat transfer system includes a tube arranged to conduct fluid so that heat is transferred from the exhaust gas to the fluid, whereby the heat transfer rate is not effective since the heat transfer surface area is less and heavy pressure drop causes to reduced coolant flow rate.
US006151891 teaches a heat exchanger for a motor vehicle exhaust includes an outer tubular body and an inner tubular body. The outer tubular body has peripheral sidewalls, an interior cavity, a first end and a second end. The inner tubular body has fluid impervious sidewalls formed out of a single length of conduit wound in a spiral coil. The spiral coil has an exterior surface and an interior surface. The inner tubular body is disposed within the interior cavity of the outer tubular body spaced from the peripheral sidewalls. This provides a first flow channel between the exterior surface of the inner tubular body, and the peripheral sidewalls of the outer tubular body, and a second flow channel along the interior surface of the inner tubular body. The conduit of the spiral coil has in inlet end and an outlet end, whereby fluid is circulated through the coil and in addition to this there is higher coolant side pressure drop while the


fluid is flowing through the single spiral coil and the heat transfer effectiveness will be much reduced.
OBJECTS OF INVENTION
The main object of this invention is to provide a silencer with heat exchanger for vehicles, which can assist in cabin heating by utilization of waste exhaust gases.
Another object of this invention is to provide silencer with heat exchanger for vehicles, which can assist in improving the inlet gas temperature of catalytic converter.
Yet another object of this invention is to provide silencer with heat exchanger for vehicles, which can maintain desired temperature inside the cabin.
Yet another object of this invention is to provide silencer with heat exchanger for vehicles, which is simple in construction and cost effective.
Yet further object of this invention is to provide silencer with heat exchanger for vehicles, which is easy to service.
STATEMENT OF INVENTION
Silencer with heat exchanger for vehicles comprising of silencer casing having inlet and outlet and heat exchanger with inlet and outlet, wherein said silencer casing is having inlet with diverging zone, body portion and outlet with conversing zone, said heat exchanger is having plurality of tubes sealingly fixed to perforated plates at both ends, said heat exchanger is provided inside said silencer casing in such a way that one of said perforated plate is sealingly


fixed in said diverging zone and other perforated plate is sealingly fixed in said conversing zone of said silencer casing.
Silencer with heat exchanger for vehicles wherein said heat exchanger is further provided with one or more deflectors placed in between said perforated plates to divert the fluid in a particular direction/fashion.
Silencer with heat exchanger for vehicles wherein Said pluralities of tubes are further provided with extended surfaces preferably fins to increase the contact surface area of said tubes.
Silencer with heat exchanger for vehicles wherein said body portion is either elliptical, circular, rectangular or triangular in shape.
Silencer with heat exchanger for vehicles wherein said heat exchanger is provided with inlet and outlet by providing opening in body portion of silencer casing on its outer surface at its extreme ends.
Silencer with heat exchanger for vehicles wherein said heat exchanger tubes are having either elliptical, circular, rectangular or triangular shape.
Silencer with heat exchanger for vehicles wherein said pluralities of tubes are further provided with extended surfaces preferably fins which can be of any shape and size.
Silencer with heat exchanger for vehicles wherein said coolant pump is connected either near to or faraway from the heat exchanger, for circulation of fluid.
Vehicle fitted with silencer with heat exchanger.


BRIEF DESCRIPTION OF INVENTION
Silencer with heat exchanger for vehicles in accordance with this invention basically comprises of silencer casing with inlet and outlet and heat exchanger with inlet and outlet. Wherein said silencer casing is having inlet with diverging zone, body portion and outlet with conversing zone. Said body portion is having either elliptical, circular, rectangular or triangular shape. Said heat exchanger is having plurality of tube held in its position through perforated plates. Said heat exchanger is provided inside said silencer in such a way that one end of bundle of said tubes through perforated plate is sealingly fixed in said diverging zone and other end is sealingly fixed through another perforated plate in said conversing zone of said silencer casing. Said body portion of casing is provided with openings on its outer surface for fluid inlet and outlet at its extreme ends.
Said heat exchanger is further provided with one or more deflectors placed in between said perforated plates to divert the fluid in a particular direction/fashion. Said pluralities of tubes are further provided with extended surfaces preferably fins to increase the surface area of said tubes.
Said silencer with heat exchanger may be a pre-silencer or main silencer, if it is a pre-silencer it is placed in between the catalytic converter and main silencer connected with tube to lay down the path for exhaust gases.
When engine is in running condition the exhaust gases passes through plurality of tubes and coolant passes around said tubes, due to which the coolant absorbs heat from the exhaust gases.


The heated coolant flows through the coolant hose of the pre-silencer outlet into the cabin heater. The coolant rejects heat to the air, which is circulated by the blower for heating up the passenger compartment.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 - Shows isometric view of coolant circuit along with silencer with heat
exchanger for vehicles
Fig.2 - Shows top view of coolant circuit along with silencer with heat
exchanger for vehicles
Figs. 3 and 4 - Show isometric view of silencer with heat exchanger for
vehicles in accordance with this invention
Fig. 5 - Shows isometric view of heat exchanger used in this invention
Fig. 6 - Shows sectional view of silencer with heat exchanger
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same,
Now referring Figures 1 to 6,
Silencer with heat exchanger for vehicles in accordance with this invention basically comprises of silencer casing (1) with inlet and outlet and heat exchanger (39) with inlet (26) and outlet (27). Wherein said silencer casing is having inlet with diverging zone (3), body portion (la) and outlet with conversing zone (2). Said body portion (la) is having either elliptical, circular, rectangular, triangular in shape. Said heat exchanger (39) is having plurality of tubes (30) held in its position through perforated plates (31,32). Said heat exchanger is provided inside said silencer casing (1) in such a way that one end


of bundle of said tubes through perforated plate (31) is sealingly fixed in said diverging zone (3) and other end is sealingly fixed through another perforated plate (32) in said conversing zone (2) of said silencer casing. Said body portion (la) of silencer casing (1) is provided with openings (26, 27) on its outer surface for fluid inlet and outlet at its extreme ends.
Said heat exchanger is further provided with one or more deflectors (41) placed in between said perforated plates (31, 32) to divert the fluid in a particular direction/fashion. Said pluralities of tubes (30) are further provided with extended surfaces (42) preferably fins to increase the surface area of said tubes.
Said silencer with heat exchanger may be a Pre-silencer or main silencer, if it is a pre-silencer it is placed in between the catalytic converter (22) and main silencer connected with tube to lay down the path for exhaust gases (9).
When engine is in running condition the exhaust gases passes through plurality of tubes and coolant passes around said tubes, due to which the coolant absorbs heat from the exhaust gases.
The heated coolant flows through the coolant hose (5) of the pre-silencer outlet into the cabin heater (10). The coolant rejects heat to the air, which is circulated by the blower for heating up the passenger compartment.
Said silencer casing is equipped with heat exchanger (39) connected with coolant inlet and coolant outlet. This allows the coolant to flow through the peripheral space (37) between said tubes. Exhaust gas hollow tube (24) from engine block (15) is connected to catalytic converter (22). Said catalytic converter is connected to said pre-silencer through tube (28). The outlet of the pre-silencer exhaust gas outlet (8) is connected to main silencer.


When engine is in running condition the coolant absorb heat from the engine housing and comes out through upper cooling line (14) and gets divided near the thermostat (17). Some amount of coolant passes through by-pass line (21) and back to suction of the engine coolant pump (12) and some amount of coolant passes through the suction hose (16) to the coolant pump (13). Remaining coolant passes through the radiator (19) through coolant hose(20). When the temperature of the coolant reaches to a set value of thermostat, then thermostat allows the coolant to flow through the said radiator to safe guard the engine block (15). When the temperature of the coolant is well within the set value of said thermostat, thermostat (17) does not open and all the coolant passes through by-pass line (21) and suction hose (16). Once the temperature reaches its design value the thermostat (17) starts opening and the coolant will be flowing through the radiator (19) gets cooled by the ram air and flows back to the suction of the engine coolant pump (12). Said coolant pump (13) pumps the coolant into the inlet (26) of said heat exchanger through coolant hose (4).
The coolant (40) enters said heat exchanger (39) through the coolant inlet tube (26) and passes over the circular tube outer periphery (36) between said circular tubes. Coolant (40) gets heated up by the exhaust gases (9) and leaves said silencer casing through coolant outlet opening (27) and passes into the cabin heater coolant hose inlet (5) and into the cabin heater (10). The coolant (40) rejects heat to the air, which is circulated by the blower for heating up the passenger compartment.
The relative cold coolant passes through the coolant hose outlet (11) from the cabin heater (10) back to the suction of the engine coolant pump (12). Engine coolant pump (12) circulates the total collected coolant (40) from by-pass line (21), cabin heater (10) and radiator (19) back to the engine (15) for removing the generated heat.


The mixture of the air and fuel ignites through compression by means of high pressure or through ignition of spark plug. The mixture burs and generate heat in turns converted to power for driving the vehicle. The generated heat will be converted into three categories. Some percentage of the heat converts to mechanical work i.e. power, some percentage of the heat rejects to coolant in the engine block and some percentage is carried away by the combustion gases which can be referred as exhaust gases (9) also. The exhaust gases (9) that are leaving the engine (15) carry tremendous amount of energy which going as waste. If exhaust gas (9) heat can be re-used, enormous quantity of power and fuel can be saved and quick and fast heating effect can be delivered for the passenger comfort. The exhaust gases from the engine passes through the catalytic converter (22) and get heated up due to the reactions between the various gases for better emission level. The catalytic converter (22) delivers its best performance once its heats up to its design intended function for better emission control.
Said silencer acts back pressure to the flow of exhaust gases (9) for reducing the noise level. A compact heat exchanger (39) is provided in said silencer casing (1) to extract heat from the exhaust gases (9) passing through the circular tubes (30) and in turn to heat up the coolant (40) flowing through the circular tubes cavity (37). The relatively less temperature exhausts gases from the pre-silencer leaves to the main silencer.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.


WE CLAIM
1. Silencer with heat exchanger for vehicles comprising of silencer casing having inlet and outlet and heat exchanger with inlet and outlet, wherein said silencer casing is having inlet with diverging zone, body portion and outlet with conversing zone, said heat exchanger is having plurality of tubes sealingly fixed to perforated plates at both ends, said heat exchanger is provided inside said silencer casing in such a way that one of said perforated plate is sealingly fixed in said diverging zone and other perforated plate is sealingly fixed in said conversing zone of said silencer casing.
2. Silencer with heat exchanger for vehicles as claimed in claim 1, wherein said heat exchanger is further provided with one or more deflectors placed in between said perforated plates to divert the fluid in a particular direction/fashion.
3. Silencer with heat exchanger for vehicles as claimed in claims 1 and 2, wherein Said pluralities of tubes are further provided with extended surfaces preferably fins to increase the contact surface area of said tubes.
4. Silencer with heat exchanger for vehicles as claimed in claims 1 to 3, wherein said body portion is having either elliptical, circular, rectangular, triangular in shape.
5. Silencer with heat exchanger for vehicles as claimed in claims 1 to 4, wherein said heat exchanger is provided with inlet and outlet by providing opening in body portion of silencer casing on its outer surface at its extreme ends.
6. Silencer with heat exchanger for vehicles as claimed in claims 1 to 5, wherein said heat exchanger tubes are having either elliptical, circular, rectangular, triangular in shape.


7. Silencer with heat exchanger for vehicles as claimed in claims 1 to 6,
wherein Said pluralities of tubes are further provided with extended
surfaces preferably fins which can be of any shape and size.
8. Silencer with heat exchanger for vehicles as claimed in claims 1 to 7,
wherein Said coolant pump is connected either near or faraway from the
heat exchanger for circulation of fluid.
9. Vehicle fitted with Silencer with heat exchanger as claimed in claims 1
to 8.
10 Silencer with heat exchanger for vehicles substantially as herein
described with reference to accompanying drawings.




ABSTRACT
Silencer With Heat Exchanger For Vehicles
This invention relates to a silencer with heat exchanger for vehicles comprising of silencer casing having inlet and outlet and heat exchanger with inlet and outlet, wherein said silencer casing is having inlet with diverging zone, body portion and outlet with conversing zone, said heat exchanger is having plurality of tubes sealingly fixed to perforated plates at both ends, said heat exchanger is provided inside said silencer casing in such a way that one of said perforated plate is sealingly fixed in said diverging zone and other perforated plate is sealingly fixed in said conversing zone of said silencer casing. Fig.l