CN205007830U - Denitration dust pelletizing system of industrial stoves flue gas - Google Patents

Abstract

The denitrification and dust removal system for industrial kiln flue gas, including slaked lime injection device, flue gas mixing device, high-efficiency dust collector, ammonia injection device, fluidized bed reactor; On the pipeline, the outlet of the dust collector is connected with the inlet flue of the reactor, and a flow guide device is installed respectively. There is an ash hopper under the flue, and the ammonia injection device and the flow equalizer are installed on the inlet flue of the reactor; The inside of the fluidized bed reactor is provided with a porous plate for placing catalyst particles, and holes for catalyst feeding and discharging are arranged on the reactor.

Description

A denitrification and dust removal system for industrial kiln flue gas

Technical field:

The utility model relates to the technical field of dedusting and denitrification of industrial kiln tail gas, and is particularly suitable for denitrification and dust removal of sintering flue gas, coal-fired boiler flue gas and cement industry flue gas.

Background technique:

With the gradual increase of air pollution control efforts, the policy focus has begun to shift to heavy polluting industries such as steel, cement and flat glass. The air pollution control plans of the Beijing-Tianjin-Hebei region, the Yangtze River Delta and the Pearl River Delta specifically proposed specific rectification tasks for the four key pollution control industries of electric power, steel, cement and flat glass. Among them, the transformation market of the iron and steel industry is the most impressive. It is estimated that from 2015 to 2020, the transformation market of steel flue gas treatment facilities will reach 16 billion yuan. The temperature of the conventional SCR denitrification reaction is 280-420°C, but the flue gas temperature of many industrial boilers is relatively low, usually less than 200°C. Although there are medium and low temperature denitrification catalysts developed on the market, at this temperature, NH3 will interact with the flue gas. The SO3 in the gas reacts to form a viscous substance, which blocks the pores of the catalyst and reduces the performance of the catalyst. In the power industry, when the unit is running at low load and the flue gas temperature is lower than 280°C, this problem also exists. At this time, the SCR reactor is usually disabled, and the pollutant emissions will exceed the standard.

Utility model content:

The technical problem to be solved by the utility model is to provide an industrial kiln flue gas SCR denitrification system suitable for lower temperature, long service life, high efficiency and low cost of use.

In order to solve the above-mentioned technical problems, the technical proposal of the present invention is a denitrification and dust removal system for industrial kiln flue gas, which is characterized in that it includes a slaked lime injection device, a flue gas mixing device, a dust collector, an ammonia injection device, and a fluidized bed reactor; The slaked lime injection device and the flue gas mixing device are respectively installed on the intake pipe of the high-efficiency dust collector. The outlet of the dust collector is connected with the inlet flue of the reactor, and a flow guide device is installed respectively. There is an ash hopper under the flue. The ammonia injection device and the flow equalizer are installed on the inlet flue of the reactor; the inside of the fluidized bed reactor is provided with a porous plate for placing catalyst particles, and holes for catalyst feeding and discharging are arranged on the reactor.

Further, one or more layers of catalysts are arranged inside the fluidized bed reactor.

Further, the main active material of the catalyst used is V ₂ O ₅ -WO ₃ or V ₂ O ₅ -MoO ₃ .

Further, it includes installing a temperature measuring device and an SO ₃ detection device in the flue of the industrial kiln, and several nozzles facing the flue gas flow of the coal-fired boiler.

The dust collector can be selected according to the actual situation, and it can be a bag filter, an electric dust collector or a ceramic filter, etc.

Utilize the denitrification and dust removal method of the industrial kiln flue gas of the device of the present utility model, its step is: 1) in industrial kiln flue, to flue gas spray slaked lime to remove SO in the flue gas, the calcium sulfite particle that produces and flue gas 2) The flue gas after dust removal passes through the fluidized bed reactor, and reacts with ammonia gas under the action of the catalyst for denitrification, thereby completing dust removal and denitrification.

The described slaked lime injection device includes SO3 detection system, several slaked lime injection nozzles facing the flue gas flow direction, and a nozzle spray volume control system. Add slaked lime and the amount of slaked lime. When the temperature is lower than 240°C, slaked lime needs to be sprayed. The amount of slaked lime depends on the concentration of SO3, which is set at 3 to 5 times the theoretical consumption. SO3 can be stably controlled within 10ppm.

The utility model has beneficial effects. In the SCR denitrification system of the flue gas of the industrial kiln, the SO3 in the flue gas is absorbed by spraying lime in front of the dust collector, and the generated calcium sulfite is intercepted by the dust collector to avoid SO3 at low temperature. The reaction with NH3 to generate ammonium sulfate has a negative impact on the denitrification process. Due to the use of a high-efficiency dust collector to finely treat the particles, there is almost no dust at the outlet of the dust collector, which effectively prevents catalyst poisoning and corrosion in the fluidized bed, and not only prolongs catalyst life. Longer service life and lower operating costs; compared with modular catalysts, the flow-type catalyst has less pressure loss, can reduce the amount of catalyst used, increase the contact area between the catalyst and flue gas, improve denitrification efficiency, and save operating costs.

Description of drawings

Fig. 1 is a structural representation of the utility model.

detailed description

Taking sintering flue gas denitrification in the iron and steel industry as an example, Figure 1 is a schematic structural diagram of the device. As shown in the figure, the system mainly includes slaked lime injection device 1, flue gas mixing devices 2 and 10, bag filter 3, ammonia injection Device 9, fluidized bed reactor 13. The slaked lime injection device 1 and the flue gas mixing device 2 are respectively installed on the intake pipe of the bag filter 3, the outlet flue 5 of the dust collector is connected with the inlet flue 6 of the reactor, and deflectors 4 and 8 are installed respectively An ash hopper 7 is arranged below the flue 6 , and an ammonia injection device 9 and a flow equalizer 10 are installed on the inlet flue of the reactor 13 . A perforated plate 12 for placing catalyst particles is provided inside the reactor 13, and a manhole 11 for catalyst feeding and discharging is arranged on the reactor 13. The smoke outlet 15, the slaked lime injection device 1 includes SO3 detection system, several nozzles facing the direction of the flue gas flow and the control system, etc. It can automatically judge whether it is necessary to inject slaked lime and the amount of slaked lime according to the size of the SO3 concentration in the flue gas. The slaked lime injection device includes a SO3 detection system, a number of nozzles facing the flue gas flow direction, and a control system. It can automatically judge whether it is necessary to inject slaked lime and the amount of slaked lime according to the concentration and temperature of SO3 in the flue gas. When the temperature is lower than 240°C, slaked lime needs to be sprayed. The amount of slaked lime depends on the concentration of SO3, which is set at 3 to 5 times the theoretical consumption. SO3 can be stably controlled within 10ppm.

In this case, only one layer of catalyst particles is arranged in the reactor. Since the flue gas temperature of the sintering machine is only 120-180°C, if the flue gas temperature is heated to 320°C, and then SCR denitrification is used, although it is technically feasible, the energy consumption is too large; or a low-temperature denitrification catalyst is used, but requires There is no SO3 in the flue gas. In this case, by spraying lime in front of the dust collector 3 and absorbing SO3 in the flue gas, the generated calcium sulfite is trapped by the dust collector 3, so as to avoid the reaction of SO3 and NH3 to form ammonium sulfate at low temperature and cause damage to the denitrification process. Negative impact, due to the use of high-efficiency dust collectors for fine treatment of particulate matter, there is almost no dust at the outlet of the dust collector, thus effectively preventing catalyst agglomeration, poisoning and corrosion in the fluidized bed, not only prolonging the service life of the catalyst, but also reducing the cost of use; Compared with the modular catalyst, the pressure loss of the flow-type catalyst is small, and it can reduce the amount of catalyst used, increase the contact area between the catalyst and the flue gas, improve the denitrification efficiency, and save operating costs.

Slaked lime is slaked lime suspension or slaked lime solid particles. The specific surface area of the slaked lime particles is 28-40 cm ² /g.

The above is only a preferred embodiment of the utility model, and is not intended to limit the utility model. Any modification, equivalent replacement and improvement within the spirit and principles of the utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (4)

1. the denitration dust removal system of industrial furnace smoke, is characterized in that, comprises calcium hydroxide injection apparatus, flue gas mixing arrangement, deduster, ammonia-gas spraying device, fluidized-bed reactor; Calcium hydroxide injection apparatus, flue gas mixing arrangement are arranged on the admission line of high-efficiency dust remover respectively, the outlet of deduster is connected with the inlet flue duct of reactor, and being separately installed with guiding device, be provided with ash bucket below this flue, ammonia-gas spraying device and current equalizer are arranged on the gas approach of reactor; Fluidized-bed reactor inside is provided with porous plate for placing catalyst granules, reactor is furnished with and feeds in raw material for catalyst and the hole of discharging.

2. the denitration dust removal system of a kind of industrial furnace smoke according to claim 1, is characterized in that,

Fluidized-bed reactor inside arranges one or more layers catalyst.

3. the denitration dust removal system of industrial furnace smoke according to claim 1, is characterized in that being included in Industrial Stoves flue and installs temperature measuring equipment and SO ₃checkout gear, several just to fire coal boiler fume flow to nozzle.

4. the denitration dust removal system of industrial furnace smoke according to claim 1, is characterized in that deduster is sack cleaner, electric cleaner or ceramic filter.