Method and device for introducing liquid into an exhaust-gas purification system
First Claim
1. A method for operating an exhaust-gas purification device, which comprises:
- drawing a liquid from a reservoir through a supply line;
introducing the liquid into an exhaust gas in an exhaust of a combustion system during combustion, for chemical purification of the exhaust gas; and
draining at least a section of the supply line with a pressurized gas during a shutdown of the combustion system.
3 Assignments
0 Petitions
Accused Products
Abstract
Nitrogen oxides emitted by an internal-combustion engine operated with excess air are normally converted by the method of selective catalytic reduction by bringing the nitrogen oxides, together with ammonia, into contact with a selective catalyst. Due to the dangers associated with the use of ammonia, in a motor vehicle ammonia should only be carried in the form of a substance which liberates ammonia, generally an aqueous urea solution. A method and a device for introducing liquid into an exhaust-gas purification system according to the invention avoids frost damage to sections of the system during shutdown times and permits operation of the system at temperatures below the freezing point of the reducing agent solution being used. The method and device include a (thermally insulated) reservoir for the reducing agent liquid and a liquid supply line which is connected thereto and terminates in an outlet opening for the liquid. The reservoir and the liquid supply line can be heated. Furthermore, a heater is provided for liquefying a starting volume which is small as compared with the volume of the reservoir. The liquid supply line may also have a back-flush valve to which a gas that is under pressure can be applied. The supply line can consequently be blown free.
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Citations
27 Claims
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1. A method for operating an exhaust-gas purification device, which comprises:
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drawing a liquid from a reservoir through a supply line; introducing the liquid into an exhaust gas in an exhaust of a combustion system during combustion, for chemical purification of the exhaust gas; and draining at least a section of the supply line with a pressurized gas during a shutdown of the combustion system. - View Dependent Claims (2, 3, 4, 7, 8)
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5. A method of operating an exhaust-gas purification device, which comprises:
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drawing a liquid through a supply line from a reservoir having a given volume; introducing the liquid into an exhaust gas in an exhaust of a combustion system during combustion, for chemical purification of the exhaust gas; and heating a starting volume of the liquid being smaller than the given volume with a heater and introducing the starting volume into the exhaust gas, no later than during startup of the combustion system. - View Dependent Claims (6)
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9. A device for operating an exhaust-gas purification device, comprising:
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a reservoir for a liquid; a supply line connected between said reservoir and an exhaust-gas purification device; a pressurized-gas inlet; and a valve connected between said pressurized-gas inlet and said supply line for introducing pressurized gas into said supply line in a direction towards said reservoir. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. An exhaust-gas purification system of a utility motor vehicle having an internal-combustion engine, the system comprising:
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a reservoir for a liquid; a supply line connected between said reservoir and an exhaust-gas purification device; a pressurized-gas inlet; and a valve connected between said pressurized-gas inlet and said supply line for introducing pressurized gas into said supply line in a direction towards said reservoir. - View Dependent Claims (27)
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Specification