Forced draft cooling system for an exhaust gas purifying device

Claim 2

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, means disposed on the connection between said first mentioned means and said air jacket for controlling the flow of the cooling air in response to an engine condition, and a non-return valve connected in series with said controlling means for preventing the flow of air, that has been passed through said controlling means, from said air jacket to said cooling air supply means while permitting the flow of said air from said cooling air supply means to the air jacket.

Claim 3

A system as claimed in claim 1, wherein said air source includes an air pump adapted to be driven by said engine.

Claim 4

A system as claimed in claim 1, wherein said controlling means is a thermo valve adapted to control the flow of the cooling air in response to the temperature of at least one of the engine and the exhaust system.

Claim 5

A system as claimed in claim 1, further comprising a relief valve disposed on the connection between said air source to the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 6

A system as claimed in claim 1, wherein said secondary air supply meaNs includes a secondary air controlling device for controlling the flow of the secondary air in response to the engine condition.

Claim 7

A system as claimed in claim 3, wherein said secondary air supply means includes a secondary air controlling device for controlling the flow of the secondary air in response to an engine condition.

Claim 8

A system as claimed in claim 5, wherein said secondary air controlling device comprises a check valve.

Claim 9

A system as claimed in claim 5, wherein said secondary air controlling device comprises a series connected combination of a check valve and a cut-off valve capable of cutting off the communication between said air source and said check valve when the engine speed exceeds a predetermined value.

Claim 10

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, a cooling air control device included in said first mentioned means for controlling the flow of the cooling air in response to an engine condition, and a non-return valve connected in series with said cooling air control device between the latter and said air jacket for preventing the flow of air, that has been passed through said control device, from said air jacket to said control device while permitting the flow of said air from said control device to said air jacket.

Claim 11

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, a cooling air control device included in said first mentioned means for controlling the flow of the cooling air in response to an engine condition, and a non-return valve connected in series with said cooling air control device between the latter and said air jacket for preventing the flow of air, that has been passed through said control device, from said air jacket to said control device while permitting the flow of said air from said control device to said air jacket.

Claim 12

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, a cooling air control device included in said first mentioned means for controlling the flow of the cooling air in response to an engine condition, and a thermo valve connected in series with said cooling air control device between the latter and said air jacket for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system.

Claim 13

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, a cooling air control device included in said first mentioned means for controlling the flow of the cooling air in response to an engine condition, and a thermo valve connected in series with said cooling air control device between the latter and said air jacket for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system.

Claim 14

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed, a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a relief valve disposed between said air source and said parallely disposed metering valve and positive relief valve for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 15

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed, a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a relief valve disposed between said air source and said parallely disposed metering valve and positive relief valve for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 16

A system as claimed in claim 11, wherein said secondary air supply means includes a secondary air control device for controlling the flow of the secondary air therethrough in response to an engine condition.

Claim 17

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed, a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a thermo valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system.

Claim 18

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed, a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a thermo valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system.

Claim 19

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a non-return Valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction.

Claim 20

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, and a non-return Valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction.

Claim 21

A system as claimed in claim 14, further comprising a thermo valve disposed between said metering valve and said positive relief valve and said non-return valve for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system.

Claim 22

A system as claimed in claim 14, wherein said secondary air supply means includes a secondary air control device for controlling the flow of the secondary air therethrough in response to an engine condition.

Claim 23

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through of said metering valve and said positive relief valve, from said air jacket to of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 24

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the reburning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through of said metering valve and said positive relief valve, from said air jacket to of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 25

A system as claimed in claim 17, wherein said secondary air supply means includes a secondary air control device for controlling the flow of the secondary air therethrough in response to an engine condition.

Claim 26

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, a thermo valve disposed between said pair of parallely disposed metering valve and positive relief valve and said non-return valve for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 27

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between said parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, a thermo valve disposed between said pair of parallely disposed metering valve and positive relief valve and said non-return valve for controlling the flow of the cooling air therethrough in response to the temperature of at least one of the engine and the exhaust system, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 28

A system as claimed in claim 19, wherein said secondary air supply means includes a secondary air control device for controlling the flow of the secondary air therethrough in response to an engine condition.

Claim 29

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between a pair of parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, said secondary air supply means including a series connected combination of a check valve and a cut-off valve capable of cutting off the communication between said air source and said check valve when the engine speed exceeds a predetermined value, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 30

A forced draft cooling system adaptable in an exhaust gas purifying device including a thermal reactor for purifying noxious compounds present in an exhaust gas emitted from the exhaust system of an internal combustion engine, which comprises an air source, means connected with said air source for supplying air to said reactor, said reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of the noxious gas present in the exhaust gas can be effected by re-burning said noxious compounds, said air from said air source through said air supply means being supplied to said air jacket of said reactor as a cooling air for forcibly cooling said shell, means connected with said air source for supplying secondary air to said reaction chamber to enable the re-burning of said noxious compounds to take place in said reaction chamber, said first mentioned means including a metering valve for controlling the flow of the air from the air source to the air jacket in response to the engine speed and a positive relief valve connected in parallel with said metering valve for permitting the substantially whole amount of air from the air source to flow to the air jacket when the engine speed exceeds a predetermined value, a non-return valve connected between a pair of parallely disposed metering valve and positive relief valve and said air jacket for preventing the flow of air, that has been passed through at least one of said metering valve and said positive relief valve, from said air jacket to at least one of said metering valve and said positive relief valve while permitting the flow of said air in the reverse direction, said secondary air supply means including a series connected combination of a check valve and a cut-off valve capable of cutting off the communication between said air source and said check valve when the engine speed exceeds a predetermined value, and a relief valve disposed on the connection between said air source and the atmosphere for exhausting the air to the atmosphere when the pressure of said air supplied from said air source exceeds a predetermined value.

Claim 31

A system as claimed in claim 21, wherein said metering valve, said positive relief valve, said check valve and said cut-off valve are all assembled into a single valve structure which comprises a casing having first through fifth working chambers, the first working chamber being communicated with a vacuum generating area of the engine, the second working chamber being communicated with the atmosphere, the third working chamber being communicated with the air jaCket, the fourth working chamber being communicated with the atmosphere through said relief valve and the air source, and the fifth working chamber being communicated with the reaction chamber of the reactor through the exhaust system, a piston rod having one end situated within the second working chamber and rigidly connected with a diaphragm member partitioning between said first and second working chambers, said diaphragm member being normally urged to a first position by a compression spring, and the other end situated within said third working chamber and rigidly connected with a first valving member of the size sufficient enough to close said third working chamber, said first valving member being formed with a hole adapted to communicate between said fourth working chamber and said third working chamber, a second valving member slidably mounted on said piston rod within said third working chamber and normally urged to the first valving member by a compression spring so as to close said hole of said first valving member, a rigid member partitioning between said fourth and fifth working chamber and formed with a hole of the diameter smaller than that of said first valving member which is adapted to communicate between said fourth and fifth working chambers, a third valving member disposed within said fifth working chamber and normally urged to said rigid member by a compression spring so as to close said hole, whereby, when the piston rod is in the other position and the pressure of the air supplied from the air source to said fourth working chamber is of the value lower than the resiliency of said second mentioned compression spring, the air in the fourth working chamber can be supplied to the reaction chamber pushing the third valving member against the third mentioned compression spring and in part to the relief valve and, when the piston rod is in said other position and the pressure of the air supplied from the air source to said fourth working chamber is of the value sufficient enough to overcome the resiliency of said second mentioned compression spring, the air in the fourth working chamber can be in part supplied to the air jacket through the hole of the first valving member and then the third working chamber, in part to the relief valve and in part to the reaction chamber through the fifth working chamber, provided that the latter can be achieved only when the pressure of that portion of the air in the fourth working chamber is of the value sufficient enough to overcome the resiliency of the second mentioned compression spring, and, when said piston rod is in the first position, said hole of said rigid member can be closed by said first mentioned valving member so that the air supplied to the fourth working chamber can be in part supplied to the air jacket through the third working chamber and in part to the relief valve.

Claim 32

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, and cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, said cooling air control means including a cooling air control device for controlling the flow of cooling air in said cooling air line means as a function of an engine operating condition and a thermo valve connected in series with and between said cooling air control device and said cooling air jacket, said thermo valve including means for controlling the flow of cooling air therethrough as a function of the temperature of at least one of the engine and the exhaust systEm of the engine.

Claim 33

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, and cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, said cooling air control means including a cooling air control device for controlling the flow of cooling air in said cooling air line means as a function of an engine operating condition and a thermo valve connected in series with and between said cooling air control device and said cooling air jacket, said thermo valve including means for controlling the flow of cooling air therethrough as a function of the temperature of at least one of the engine and the exhaust systEm of the engine.

Claim 34

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, wherein said cooling air control means includes a metering valve and a positive relief valve arranged in said cooling air line means in parallel flow relationship with one another, wherein said metering valve includes means for varying the flow of air therethrough as a function of at least one engine operating parameter, wherein said positive relief valve is closed at low engine speeds such that said metering valve effectively controls the cooling air flow to said cooling air jacket during low engine speed operation, wherein said positive relief valve is opened in response to engine speeds above a predetermined value such that substantially the whole amount of cooling air supplied by the air source is supplied as cooling air to said cooling air jacket irrespective of the position of said metering valve, and a non-return valve interposed between said cooling air jacket and said parallely disposed metering and positive relief valves for preventing the backflow of cooling air from said cooling air jacket to said metering and positive relief valves and said air source.

Claim 35

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, wherein said cooling air control means includes a metering valve and a positive relief valve arranged in said cooling air line means in parallel flow relationship with one another, wherein said metering valve includes means for varying the flow of air therethrough as a function of at least one engine operating parameter, wherein said positive relief valve is closed at low engine speeds such that said metering valve effectively controls the cooling air flow to said cooling air jacket during low engine speed operation, wherein said positive relief valve is opened in response to engine speeds above a predetermined value such that substantially the whole amount of cooling air supplied by the air source is supplied as cooling air to said cooling air jacket irrespective of the position of said metering valve, and a non-return valve interposed between said cooling air jacket and said parallely disposed metering and positive relief valves for preventing the backflow of cooling air from said cooling air jacket to said metering and positive relief valves and said air source.

Claim 36

An installation according to claim 24, wherein said at least one engine operating parameter controlling said metering valve includes engine operating speed.

Claim 37

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, wherein said cooling air control means includes a metering valve and a positive relief valve arranged in said cooling air line means in parallel flow relationship with one another, wherein said metering valve includes means for varying the flow of air therethrough as a function of at least one engine operating parameter, wherein said positive relief valve is closed at low engine speeds such that said metering valve effectively controls the cooling air flow to said cooling air jacket during low engine speed operation, wherein said positive relief valve is opened in response to engine speeds above a predetermined value such that substantially the whole amount of cooling air supplied by the air source is supplied as cooling air to said cooling air jacket irrespective of the position of said metering valve, and a thermo valve interposed between said cooling air jacket and said parallely disposed metering and positive relief values for controlling the flow of cooling air therethrough as a function of the temperature of at least one of the engine and the exhaust system of the engine.

Claim 38

An exhaust gas purifying installation for an internal combustion engine comprising: an air source for supplying air under pressure, a thermal reactor including a cooling air jacket surrounding a shell which defines therein a reaction chamber in which reduction of the amount of noxious compounds present in the exhaust gas can be effected by re-burning said exhaust gas, cooling air line means connected between said air source and said cooling air jacket for supplying cooling air to said cooling air jacket, cooling air control means interposed in said cooling air line means for controlling the amount of cooling air supplied to said cooling air jacket, wherein said cooling air control means includes a metering valve and a positive relief valve arranged in said cooling air line means in parallel flow relationship with one another, wherein said metering valve includes means for varying the flow of air therethrough as a function of at least one engine operating parameter, wherein said positive relief valve is closed at low engine speeds such that said metering valve effectively controls the cooling air flow to said cooling air jacket during low engine speed operation, wherein said positive relief valve is opened in response to engine speeds above a predetermined value such that substantially the whole amount of cooling air supplied by the air source is supplied as cooling air to said cooling air jacket irrespective of the position of said metering valve, and a thermo valve interposed between said cooling air jacket and said parallely disposed metering and positive relief values for controlling the flow of cooling air therethrough as a function of the temperature of at least one of the engine and the exhaust system of the engine.

Claim 39

An installation according to claim 26, further comprising a relief valve in said cooling air line means between said air source and said parallely disposed metering and positive relief valves for exhausting cooling air to atmosphere when the pressure supplied from said air sOurce exceeds a predetermined value.

Claim 40

An installation according to claim 24, further comprising a relief valve in said cooling air line means between said air source and said parallely disposed metering and positive relief valves for exhausting cooling air to atmosphere when the pressure supplied from said air source exceeds a predetermined value.

Claim 41

An installation according to claim 24, further comprising a thermo valve interposed between said non-return valve and said parallely disposed metering and positive relief valves for controlling the flow of cooling air therethrough as a function of the temperature of at least one of the engine and the exhaust system of the engine.

Claim 42

An installation according to claim 29, further comprising a relief valve in said cooling air line means between said air source and said parallely disposed metering and positive relief valves for exhausting cooling air to atmosphere when the pressure supplied from said air source exceeds a predetermined value.

Claim 43

A system as claimed in claim 4, wherein said secondary air supply means includes a secondary air controlling device for controlling the flow of the secondary air in response to an engine condition.

Claim 44

A system as claimed in claim 13, wherein said secondary air supply means includes a secondary air control device for controlling the flow of the secondary air therethrough in response to an engine condition.