Abstract

A method and apparatus for mixing at least one gaseous fluid stream with a large gas stream flowing in a gas duct, especially for introducing a reducing agent into a flue gas containing nitrogen oxides. The gas stream is directed against at least one disk-shaped mixer element on an inlet side that is inclined at an angle counter to the direction of flow of the gas stream, wherein eddy-type whirls form at the mixer element. The gaseous fluid stream is guided essentially to the center of an impact surface associated with the discharge side of the mixer element and is admixed with a gas stream downstream of the mixer element and is guided essentially perpendicularly onto the center of the impact surface on the discharge side such that the gaseous fluid is distributed over the entire discharge side from the center thereof and is incorporated across the entire whirl system formed at the peripheral edge of the mixer element.

IPC Classes  ?

• B01F 5/04 - Injector mixers

Abstract

A method and apparatus for mixing at least one fluid stream with a large gas stream flowing in a gas duct, especially for introducing reducing agent into flue gas containing nitrogen oxides. The gas stream is directed against at least one disk-shaped mixer element on an inlet side that is inclined at an angle counter to the direction of flow of the gas stream, wherein eddy-type whirls form at the mixer element. A swirled fluid stream is admixed with the large gas stream downstream of the mixer element.

IPC Classes  ?

• B01F 3/02 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases with gases or vapours
• B01F 5/04 - Injector mixers

Abstract

An apparatus for mixing a liquid with a large gas stream flowing in a gas duct, especially for introducing reducing agent into flue gas containing nitrogen oxides. At least one metering lance having at least two atomizer nozzles supplies liquid to the gas stream, with the nozzles being inclined relative to the direction of flow of the gas stream and being inclined in opposite directions relative to one another. At least one disk-shaped mixer element is associated with and spaced from the nozzles, and is inclined relative to the direction of flow of the gas stream. Flow eddies form at the mixer element, and at least a portion of the liquid enters the flow eddies. Atomization is effected in such a way by the mixer element that volatilized gaseous portions in the nozzle streams exiting the nozzles enter the flow eddies, while non-volatized droplet portions, due to their inertia and an atomizer angle, do not enter the flow eddies in the vicinity of the mixer element.

IPC Classes  ?

• B01F 3/04 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases or vapours with liquids

Abstract

A process is disclosed for mixing a fluid stream (F) with a large flow-rate gas stream (2), in particular for introducing a reducing agent into flue gas containing nitrogen oxides, in which process the large flow-rate gas stream impinges against the inflow side of at least one disk-like mixer element (1; 8) arranged at an angle against the direction of flow, and across which eddy currents (3) are formed, and the fluid stream is added to the large flow-rate gas stream downstream from the mixer element. In order to mix the fluid stream more completely with the large flow-rate gas stream, the fluid stream is added in the form of a swirling flow (7; 10). For that purpose, the swirling fluid flow is preferably led on the outflow side (8b) (lee side) of the mixer element (8) substantially perpendicularly to the mixer element (8) and substantially towards the centre (M) of the mixer element, and the fluid enters the eddy current from the centre of the mixer element, past its outflow side. However, it is also possible for the swirling fluid flow to be led on the inflow side (1a) (windward side) substantially perpendicularly to the mixer element (1) and to exit through an opening (8) located substantially in the centre (M) of the mixer element, on the outflow side (1b) (lee side) of the mixer element, and for the fluid to enter the eddy current from the centre of the mixer element, past the outflow side. The invention is also directed to a corresponding device.

IPC Classes  ?

• B01F 3/02 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases with gases or vapours
• B01F 3/04 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases or vapours with liquids
• B01F 5/04 - Injector mixers
• B01F 5/06 - Mixers in which the components are pressed together through slits, orifices, or screens
• B01F 15/00 - Accessories for mixers
• B01D 53/34 - Chemical or biological purification of waste gases
• B01D 53/76 - Gas phase processes, e.g. by using aerosols
• F23J 15/00 - Arrangements of devices for treating smoke or fumes

Abstract

Disclosed is a method for mixing at least one gaseous fluid flow (6; 12) with a large gas flow (2), especially to introduce a reducing agent into a flue gas containing nitrogen oxides. According to said method, the large gas flow flows against at least one mixer element (1; 8) on the intake side (windward side) thereof, said at least one mixer element, on which train-type whirls (3) are formed, being embodied similar to a disk while being disposed at an angle so as to be inclined counter to the direction of flow thereof, the fluid flow is directed to the center (M) of an impact surface 1; 18; 11) located on the discharge side (1 b; 8b) (lee side) of the mixer element, and the gaseous fluid flow is admixed to the gas flow downstream of the mixer element. In order to improve the incorporation of the fluid flow into the large gas flow, the fluid flow (F) is conducted in a substantially vertical direction onto the center (M) of the baffle surface (1; 8; 11) such that the gaseous fluid is distributed across the entire discharge side of the mixer element from the center and is introduced across the whole whirl system formed at the circumferential edge of the mixer element. Preferably, the fluid flow (6) is conducted directly to the discharge side (lee side) of the mixer element or from the intake side (windward side ) through a hole (9) located in the mixer element to a baffle plate that is arranged upstream of said hole on the discharge side (lee side). The invention also relates to a corresponding device.

IPC Classes  ?

• B01F 3/02 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases with gases or vapours
• B01F 5/04 - Injector mixers
• B01F 15/00 - Accessories for mixers
• B01D 53/34 - Chemical or biological purification of waste gases
• B01D 53/76 - Gas phase processes, e.g. by using aerosols
• F23J 15/00 - Arrangements of devices for treating smoke or fumes
• B01F 5/02 - Jet mixers
• B01F 5/06 - Mixers in which the components are pressed together through slits, orifices, or screens

Abstract

In an apparatus for mixing a fluid with a large gas stream (2) flowing in a gas duct, especially for introducing a reducing agent (5a) into a flue gas comprising nitrogen oxides, having at least one metering lance (5) with at least one nozzle (4a; 4b) for the feeding of the fluid, whose axis forms an angle with the flow direction of the gas stream, and at least one flat mixer element which is arranged at a distance from the nozzle and forms an angle with the flow direction of the gas stream, wherein flow eddies (3) are formed at the mixer element and at least some of the fluid gets into these flow eddies, deposit formation is prevented to a substantial extent in the case of direct injection of a liquid as the fluid, especially of a liquid reducing agent, with a short mixing path, in accordance with the invention by providing that, in the case of use of a liquid (5a) as the fluid, the metering lance (4) is equipped with at least two atomizer nozzles (4a, 4b) which are tilted against the flow direction of the gas stream (2) and in opposite directions to one another, such that the atomizer nozzles are assigned to a mixer element (1) with a disk-like design.

IPC Classes  ?

• B01F 3/04 - Mixing, e.g. dispersing, emulsifying, according to the phases to be mixed gases or vapours with liquids
• B01F 5/04 - Injector mixers
• B01F 5/06 - Mixers in which the components are pressed together through slits, orifices, or screens
• B01F 15/00 - Accessories for mixers
• B01D 53/34 - Chemical or biological purification of waste gases
• B01D 53/74 - General processes for purification of waste gasesApparatus or devices specially adapted therefor
• F23J 15/00 - Arrangements of devices for treating smoke or fumes