Patent Application
20190015782
The present invention is generally directed toward reagent vaporization, and more specifically, toward a reagent vaporization system utilizing exhaust gas.
Combustion exhaust gas, otherwise referred to as flue gas, is emitted as a result of the combustion of fuels such as natural gas, gasoline, petrol, diesel fuel, fuel oil, or coal. Typically contained within the combustion exhaust gas are particulates of nitrogen oxides (NOx), a pollutant. The introduction of a reagent such as ammonia or urea into the flue gas in conjunction with a catalyst can produce a reaction with the nitrogen oxides to produce nitrogen gas. The reagent can be introduced into the stream of flue gas in a vapor state.
The prior art has a number of various vaporization processes, including systems that utilize direct contact with hot exhaust gas to vaporize aqueous reagent. These systems utilize a hot fan assembly to induce flow of hot exhaust gas to an external vaporizer chamber and then reinject the combined exhaust gas/vaporized reagent into the stream of exhaust gas. These systems have the disadvantage of having high initial costs related to the hot fan and high long term costs to maintain the external components. The prior art further includes systems that utilize external electrically generated heat. These systems have the disadvantage of having high long term costs relating to the maintenance and ongoing power requirements.
Clearly, there is a need for an improved reagent vaporization system.
The present invention satisfies the needs discussed above. The present invention is generally directed toward reagent vaporization, and more specifically, toward a reagent vaporization system utilizing exhaust gas.
One aspect of the present invention is directed toward a reagent vaporization system. This system includes a vaporization chamber located within a stream of hot exhaust gas. Aqueous reagent is provided to the vaporization chamber from an external source located outside of the stream of the hot exhaust gas. In this aspect, the stream of hot exhaust gas heats the aqueous reagent located within the vaporization chamber area until vaporization. The vaporized reagent is then introduced into the stream of hot exhaust gas. The aqueous reagent source may include a reagent storage and pump; and a reagent flow control rack.
Another aspect of the present invention may also include a dilution air heating coil located within the stream of hot exhaust gas. The dilution air heating coil may be located either upstream or downstream of the vaporization chamber. Dilution air is provided to the dilution air heating coil from a dilution air apparatus located outside of the stream of hot exhaust gas. The dilution air apparatus may include an ambient dilution air blower.
It is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein are for the purpose of description and not of limitation.
Upon reading the above description, various alternative embodiments will become obvious to those skilled in the art. These embodiments are to be considered within the scope and spirit of the subject invention, which is only to be limited by the claims which follow and their equivalents.
The present invention satisfies the needs discussed above. The present invention is generally directed toward reagent vaporization, and more specifically, toward a reagent vaporization system utilizing exhaust gas.
An embodiment 10 of the present invention is illustrated in
An embodiment of the vaporization chamber 16 may comprise one or more atomizing nozzles configured to transform the aqueous reagent into a mist. The atomization of the aqueous reagent increases the surface area of the fluid, which allows for more efficient heat absorption to achieve vaporization. This embodiment may also comprise a static mixing system configured to disperse the atomized reagent. The static mixing system may include a plurality of fixed baffles configured to induce turbulence within the atomized reagent.
Another embodiment 50 of the present invention is illustrated in
This embodiment 50 may also comprise a reagent injection grid 28 located downstream from, and in communication with, the vaporization chamber 16. Reagent injection grid 28 may inject vaporized reagent into the stream of exhaust gas 14. Further downstream, the stream of exhaust gas may engage a SCR catalyst 30 which causes the NOx to convert into nitrogen gas. The location of reagent injection grid 28 and SCR catalyst 30 being downstream of vaporization chamber 16 is illustrative and not meant to be limiting. Those skilled in the art will recognize that reagent injection grid 28 and SCR catalyst 30 may be located upstream of vaporization chamber 16.
An embodiment 60 of the present invention is illustrated in
An embodiment 70 of the present invention is illustrated in
An embodiment 80 of the present invention is illustrated in
An embodiment 90 of the present invention is illustrated in
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification.
