CN201719973U - A high-efficiency ammonia denitrification device - Google Patents

Abstract

The utility model discloses a high-efficient ammonia process denitrification facility atomizes aqueous ammonia or urea solution at first normal atmospheric temperature in advance through an ammonia temperature-raising pressure boost blender, then in high temperature gasification and the denitration reaction zone who spouts the flue gas after the pressure boost produces the source, make with flue gas intensive mixing and contact reaction. The utility model discloses with the atomizing of aqueous ammonia solution or urea solution, gasification leading, just let in the flue gas after making high temperature ammonia misce bene stable and produce the source reaction zone, can promote denitration effect to about 70%, can reach 85% the highest to enlarged former SNCR's effective reaction temperature to 800 ability of cake 1100 ℃, consequently can be called high-efficient high temperature ammonia process denitration (HE-SNCR) system. Moreover, due to the adoption of the ammonia method non-catalytic selective reduction reaction, the denitration effect can be achieved under the condition of high dust, and is superior to the denitration effect of SCR or other post-treatment sections (low dust and low water-gas components).

Description

A high-efficiency ammonia denitrification device

technical field

The utility model relates to the field of flue gas denitrification, in particular to a non-coal contact ammonia method denitrification (SNCR) device.

Background technique

The effective denitrification temperature of the existing SNCR system is between 850-1050°C. The system adopts the non-coal contact ammonia method for denitrification. The ammonia liquid or urea solution with a water content of 80% is directly sprayed into the temperature reaction at room temperature through high-pressure steam or compressed air. The atomization in the area is in contact with the flue gas for denitrification. In this process, the atomized ammonia liquid or urea solution at room temperature directly exchanges heat with the high-temperature flue gas in the high-temperature reaction zone, which will cause sudden cooling in the high-temperature reaction zone, and the temperature of each area in the high-temperature reaction zone will be uneven, resulting in This leads to low denitrification efficiency. At present, the general denitrification efficiency is only 30-50%, and the denitrification effect of the system at 800 ° C is almost zero.

Contents of the invention

In order to solve the above problems, the purpose of this utility model is to provide a high-efficiency ammonia denitrification device, the denitrification efficiency is improved, and the temperature range is wider.

The purpose of this utility model is achieved in that:

A high-efficiency ammonia method denitrification device, including a flue gas generation source, is characterized in that: it also includes an ammonia temperature booster mixer, including an atomization section, a heating section, and a booster section arranged in sequence, and the ammonia gas booster The warm booster mixer is connected to the flue gas generation source through the delivery pipeline, and the ammonia gas is transported into the denitrification reaction area of the flue gas generation source.

The utility model puts the atomization and gasification of the ammonia solution or urea solution in front, so that the high-temperature ammonia gas is mixed evenly and stably before being passed into the flue gas generation source reaction area, which can improve the denitrification effect to about 70%, up to 85%. , and expanded the effective reaction temperature of the original SNCR to 800-1100 ° C, so it can be called a high-efficiency high-temperature ammonia denitrification (HE-SNCR) system. Moreover, due to the non-catalytic selective reduction reaction of the ammonia method, the above-mentioned denitrification effect can still be achieved under high dust conditions, which is better than the denitrification effect of SCR or other post-treatment sections (low dust, low water vapor components), such as CSCR and A denitrification process that uses activated coke or alumina as a catalyst (contact coal).

Description of drawings

Fig. 1 is a process flow block diagram of the present utility model;

Fig. 2 is a device schematic diagram of the present utility model;

Fig. 3 is a schematic diagram of the internal structure of the ammonia temperature-increasing booster mixer of the present invention.

Detailed ways

The utility model is a high-efficiency ammonia denitrification device, which may include an ammonia gas temperature-increasing and boosting mixer 1, a flue gas generating source (such as a boiler 2, a kiln, etc.), and a flue gas post-processor 3, and the three are sequentially connected. The ammonia temperature booster mixer 1 includes an atomization section 12, a heating section 13-15, and a pressurization section 16 arranged in sequence, and finally connected to the boiler 2 through a delivery pipeline, and the ammonia gas is sent into the boiler 2 for denitrification reaction Within District 21. The heating section is provided with a heat exchanger, a thermal mixer, an electric heating device or an external heating device, as long as the atomized ammonia solution or urea solution flows through the heating section, it can achieve uniform heating Can. Preferably, the heating section includes one or more sections. Preferably, the flue gas discharged from the boiler can be used as a heat source for heat exchange to achieve temperature increase. The heat exchanger located in the upstream heating section communicates with the flue gas post-processor 3 , and the heat exchanger located in the downstream heating section communicates with the boiler 2 . Preferably, there are more than two ammonia gas injection points in the denitration reaction zone 21 of the boiler 2 .

The utility model will be further elaborated below through specific examples in conjunction with the accompanying drawings, but the utility model is not limited to this specific example.

Example

As shown in Figure 1-3, the technological process of the present utility model is:

Step 1. Prepare ammonia solution or urea solution;

Step 2. Pass the above-mentioned ammonia solution or urea solution into the external ammonia temperature booster mixer 1, pass through the injection section 11, and enter the atomization section 12 for atomization.

Step 3. After the atomized ammonia solution or urea solution passes through the first heating section 13, the second heating section 14, and the third heating section 15 in sequence, it undergoes staged heating and gasification, and finally enters the diversion pressurization section 16, Ammonia gas with uniform temperature and pressure is formed. In each heating section, a heat exchanger is provided for heat exchange and temperature increase. In this embodiment, for the sake of environmental protection and energy saving, the gasification heat source is the high-temperature flue gas and medium-temperature flue gas of the boiler 2 or the kiln itself, as shown by the dotted arrow in Fig. 2, to achieve recycling without providing an additional heat source. The heat exchangers in the first heating section 13 and the second heating section 14 are connected to the exhaust end of the flue gas post-processor 3, and the medium-temperature flue gas passing through the flue gas post-processor 3 is transported to the first heating section 1 through pipelines. Section 13, the second heating section 14 are mixed with atomized ammonia solution or urea aqueous solution and heat exchanged (step 6); the heat exchanger of the third heating section 15 is communicated with boiler 2 exhaust end 22, by The high-temperature flue gas discharged from the boiler 2 is transported to the third heating section 15 through pipelines, and mixed with the ammonia gas heated in step (6) for heat exchange (step 5). The diversion booster section 16 can be boosted by connecting a booster fan, and the pressure can be set by the actual pressure loss.

Step 4. High-temperature and high-pressure ammonia is injected into the denitrification reaction zone of boiler 2 through pipelines. As shown in Figure 2, there are two injection points 23 in this embodiment, and ammonia is injected at a concentration lower than the minimum explosion limit. Complete efficient denitrification.

In the actual design of atomization, gasification, and heat mixing exchangers, the detailed design of the project is made according to different situations on site, and it is not a fixed standard device. In terms of technology, the utility model must be based on the actual situation of the site, combined with the current situation of the project, through the long-term accumulated practical experience, based on the mass-energy balance of the treatment system and the calculation of fluid thermodynamics. After calculation, an effective ammonia gas injection and distribution point, the purpose of which is to make the denitrification reaction area as uniform and stable as possible, so that the injection of gasified ammonia water in partitions and sections can achieve the greatest denitrification effect and reduce the extra energy consumption required for gasification of ammonia water, so as to achieve energy saving and reduction. row effect.

The utility model is a "HE_SNCR" high-efficiency ammonia method (selective non-catalytic reduction) denitrification process, through pre-atomization outside the denitrification reaction area, high-temperature vaporization and heat exchange system... and other comprehensive treatment technologies and equipment, using the injected gasification containing Ammonia gas reacts selectively with NOx, and in the unfavorable environment of high dust, it can still achieve a denitrification effect of 70% or above (minimum>60%, generally 70% or above, and maximum 85% or above). At the same time, the lower limit of the SNCR reaction is extended from 850°C to 800°C, and the denitrification effect is still 15-30% at the lower limit temperature, while the previous SNCR system has almost zero denitrification effect at 800°C.

Claims (5)

1. high-efficiency ammonia-method denitration device, comprise that flue gas produces the source, it is characterized in that: comprise that also an ammonia heats supercharging mixer, comprise sections of atomization, the section of heating and supercharging section that order is provided with, this ammonia heats supercharging mixer and is connected with flue gas generation source by transfer pipeline, carries ammonia to enter in the denitration reaction district in flue gas generation source.

2. high-efficiency ammonia-method denitration device according to claim 1 is characterized in that: the described section of heating comprise one or more than.

3. high-efficiency ammonia-method denitration device according to claim 1 and 2 is characterized in that: carry out heat exchange and heat by heat exchanger, hot blender or electric heater unit are set in the described section of heating.

4. high-efficiency ammonia-method denitration device according to claim 3, it is characterized in that: described flue gas produces the source exhaust end and is connected with the flue gas preprocessor, in the described section of heating, heat exchanger/hot the blender that is positioned at upstream position is communicated with flue gas preprocessor exhaust end, and the heat exchanger/hot blender that is positioned at downstream position produces the source exhaust end with flue gas and is communicated with.

5. high-efficiency ammonia-method denitration device according to claim 1 is characterized in that: the ammonia decanting point that described flue gas produces the denitration reaction district in source comprises more than two.

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