CN108201778A - A kind of limekiln combined denitration system - Google Patents

Abstract

The invention relates to a lime kiln combined denitration system, which comprises a compressed air storage tank, a reducing agent storage tank, a demineralized water storage tank, a denitrification agent storage tank and a lime kiln. The lime kiln is equipped with reducing agent spray guns and denitrification agent spray guns, and the compressed air storage tank is connected to the compressed air inlets of each reducing agent spray gun and denitrification agent spray gun through compressed air main pipe, compressed air sub-pipe and compressed air branch pipe. The reducing agent storage tank is connected to the reducing agent inlet of each reducing agent spray gun through the reducing agent main pipe, the reducing agent branch pipe and the reducing agent branch pipe. The denitration agent storage tank is connected to the static mixer through the denitrification pump and the meter, the desalted water storage tank is connected to the static mixer through the denitrification pump and the meter, and the static mixer is connected through the denitration agent main pipe, the denitration agent branch pipe and the denitration agent branch pipe To the denitration agent inlet of each denitration agent spray gun. The invention uses a combined denitrification system combining denitrification agent denitrification and reducing agent denitrification to carry out denitrification, thereby improving the denitrification efficiency of the selective non-catalytic reduction of flue gas from a lime kiln.

Description

A lime kiln combined denitrification system

technical field

The invention belongs to the technical field of tail gas treatment of industrial furnaces and kilns, and relates to denitrification equipment, in particular to a lime kiln combined denitrification system.

Background technique

Flue gas is the main discharge of the lime kiln, which is a mixed gas produced by the combustion of combustibles in the kiln and the decomposition of limestone. Since the flue gas contains a large amount of nitrogen oxides such as NOx, if these nitrogen oxides are directly discharged into the atmosphere, they will pollute the air, form photochemical smog and acid rain, and endanger human health. Therefore, the flue gas must be denitrified before being discharged ( That is, denitrification) treatment.

At present, there are two main technologies for flue gas denitrification: Selective Reduction Reduction (SCR) technology and Selective Non-Catalytic Reduction (SNCR) technology. Selective non-catalytic reduction (SNCR) denitrification is to uniformly spray the reducing agent containing amino groups into the area where the temperature of the flue gas is 850-1050 ° C under the condition of no catalyst, and selectively reduce the NOx in the flue gas to N ₂ And H ₂ O, in order to achieve the purpose of reducing nitrogen oxides. In addition, it was found that spraying reducing agents such as methane, hydrogen, and carbon monoxide into the high-temperature flue gas also has a certain denitrification effect. The SNCR denitrification process of the prior art is applied to the circulating fluidized bed boiler, and the denitrification efficiency is between 30-50%. It has not been found that the SNCR denitrification is applied to the field of lime kiln flue gas denitration, and the existing technology cannot fully meet the requirements of lime kiln flue gas emission. quality requirements.

Contents of the invention

The purpose of the present invention is to provide a lime kiln combined denitrification system, which combines denitrification agent denitrification and reducing agent denitrification to perform combined denitrification, so as to improve the denitrification efficiency of selective non-catalytic reduction of lime kiln flue gas.

The technical solution of the present invention is: lime kiln combined denitrification system, including compressed air storage tank, reducing agent storage tank, desalted water storage tank, denitrification agent storage tank, waste water treatment device, static mixer and lime kiln, denitrification agent storage tank and The waste water treatment unit is connected. The lime kiln is provided with a reducing agent spray gun and/or a denitration agent spray gun, the reducing agent spray gun is provided with a reducing agent inlet and a compressed air inlet, and the denitration agent spray gun is provided with a denitrification agent inlet and a compressed air inlet. The compressed air storage tank is connected to the compressed air inlets of the reducing agent spray guns and denitration agent spray guns respectively through the compressed air main pipe, the compressed air branch pipe and the compressed air branch pipe. The reductant storage tank is connected to the reductant inlet of each reductant spray gun through the reductant main pipe, the reductant branch pipe and the reductant branch pipe, and the reductant main pipe is provided with a meter. The denitration agent storage tank is connected to the static mixer through the denitrification pump and the meter, the desalted water storage tank is connected to the static mixer through the denitrification pump and the meter, and the static mixer is connected through the denitration agent main pipe, the denitration agent branch pipe and the denitration agent branch pipe To the denitration agent inlet of each denitration agent spray gun.

The lime kiln is double-chamber kiln, rotary kiln sleeve kiln, beam kiln or annular counter-fired kiln. The double-chamber kiln is provided with a calcination zone and a channel, and the channel is provided with a reducing agent spray gun and/or a denitrifying agent spray gun, and the reducing agent spray gun and the denitrifying agent spray gun are arranged in a ring on the two kiln chambers of the double-chamber kiln. The calcining zone is equipped with denitrification agent spray gun, reducing agent spray gun or composite spray gun, or any combination of denitrification agent spray gun, reducing agent spray gun and composite spray gun, or denitrification agent spray gun, reducing agent spray gun and composite spray gun are set at the same time. The composite spray gun is equipped with a reducing agent atomizer, which is provided with a denitration agent inlet and a compressed air inlet, and the outlet of the reducing agent atomizer is connected to the cooling medium channel of the spray gun. The static mixer is connected to the denitration agent inlet of the reducing agent atomizer through the denitrification main pipe, the denitrification branch pipe and the denitrification branch pipe, and the compressed air storage tank is connected to the reducing agent mist through the compressed air main pipe, compressed air branch pipe and compressed air branch pipe. compressed air inlet to the carburetor.

The calcination zone and channel are all equipped with denitration agent spray guns, or all are equipped with reducing agent spray guns, or both are installed at the same time. The composite spray gun is a single-layer or double-layer casing structure, which is set on the fuel spray gun to compositely spray the denitrification agent and/or reducing agent; or set the denitrification agent spray gun/reductant spray gun separately, independent of the fuel spray gun, and the position is above the fuel spray gun , or below the fuel spray gun, so that the denitration agent spray gun can reach deeper and higher temperature. The denitration agent spray gun and the reducing agent spray gun work in the calcined state or in the heat storage state. The denitration agent spray gun and reducing agent spray gun work under the condition of flue gas downstream or under the condition of flue gas countercurrent.

The rotary kiln includes a kiln head, a kiln tail and a preheater, and the preheater is connected to the kiln tail. A reducing agent spray gun and/or a denitration agent spray gun is installed at the kiln tail. All denitrification agent spray guns, all reducing agent spray guns, or both are installed at the kiln tail, and the ratio of the two quantities can be adjusted arbitrarily, and the total number of the two can be adjusted arbitrarily. The denitration agent is atomized by compressed air and sprayed out with the fuel, or alone. The denitration agent is ammonia water or urea or a mixture of the above two. The reducing agent is hydrogen, methane or carbon monoxide, or a mixture of the above gases, or a carbon-containing reducing gas or liquid or solid or a mixture of the above substances.

The beam kiln is equipped with a preheating zone, a calcining zone and a cooling zone. The preheating zone is equipped with an upper suction beam, and the lower part of the upper suction beam is equipped with a denitrification beam. The calcining zone is equipped with a combustion beam, and the cooling zone is equipped with a lower suction beam. beam. The upper suction beam is provided with a denitration spray gun, the lower suction beam and the denitration beam are provided with a denitration channel, the denitration spray gun and the denitration channel are provided with a denitration agent atomizer, and the denitration agent atomizer is provided with a denitrification agent inlet and a compressed air inlet. The static mixer is connected to the denitration agent inlet of the denitrification atomizer of the denitrification spray gun at the lower part of the upper suction beam, the denitrification channel of the denitrification beam and the denitrification channel of the lower suction beam through the main denitrification agent pipe, the denitrification agent branch pipe and the denitrification agent branch pipe. The compressed air storage tank is connected to the compressed air inlet of each denitrification spray gun and the denitration agent atomizer of the denitrification channel through the compressed air main pipe, compressed air branch pipe and compressed air branch pipe respectively.

The outlets of the desalinated water storage tank and the denitrification agent storage tank are provided with filters, the desalinated water storage tank is connected to the desalination water pump through the filter, and the ammonia water storage tank and the denitrification agent storage tank are connected to the denitrification pump through the filter. The desalted water storage tank and the denitrification agent storage tank are respectively provided with return pipelines, and the outlet of the desalted water pump returns to the desalted water storage tank through the return pipeline. The denitration pump is connected to the denitration agent storage tank through the return line. The denitration agent branch is equipped with a reversing valve to control the reversing of ammonia water. A reversing valve is installed on the reducing agent pipe to control the reversing operation of the reducing agent.

The lime kiln combined denitrification system of the present invention combines the denitration agent denitrification and the reducing agent denitrification to perform combined denitrification, and improves the denitrification efficiency of the selective non-catalytic reduction of flue gas in the lime kiln. The double-chamber kiln uses a compound spray gun to spray the ammonia water denitration agent mist atomized by the reducing agent atomizer into the regenerator chamber through the spray gun cooling medium channel to contact with the flue gas countercurrently, which increases the reaction time and improves the denitrification efficiency. For the cooling medium of the spray gun. The ammonia water sprayed from the denitration agent spray gun of the rotary kiln contacts with the flue gas countercurrently, which increases the reaction time and improves the denitrification efficiency.

Compared with the prior art, the beneficial effects of the lime kiln combined denitrification system of the present invention are: ① The denitrification agent denitrification system is equipped with a wastewater treatment device, which can quickly discharge the ammonia water in the denitrification agent storage tank and perform harmless treatment in case of emergency. ②The combined denitrification system is equipped with a reversing valve, and the supply of ammonia water is reversed with the periodic reversing of the double chamber kiln, realizing the continuous operation of the denitrification pump and the desalinated water pump, avoiding frequent opening of the pump and prolonging its service life. ③The denitration agent spray gun is made of high temperature resistant materials, high temperature corrosion resistance, wear resistance, large load adjustment ratio, fine atomization particle size, large output, low ammonia water pressure, low gas consumption, and long service life, which expands the load of the combined denitrification system Adjusting the range improves the denitrification effect, which is beneficial to reduce the consumption of atomization medium and power consumption. ④The denitrification pump and the desalinated water pump are both used for one use and one for standby, and filters are installed in front of the pumps, which improves the stability of the combined denitrification system. ⑤The denitrification pump and the desalinated water pump are equipped with return pipelines to prevent equipment damage and system overload, and improve the safety of the combined denitrification system; Large, expanding the load adjustment range of the system.

Description of drawings

Fig. 1 is the schematic flow sheet of lime kiln combined denitrification system of the present invention;

Fig. 2 is the schematic diagram of double chamber kiln denitrification system;

Fig. 3 is the schematic diagram of another embodiment of the present invention;

Fig. 4 is the schematic diagram of another embodiment of the present invention;

Among them: 1—compressed air storage tank, 2—reductant storage tank, 3—demineralized water storage tank, 4—denitration agent storage tank, 5—waste water treatment device, 6—flue gas channel, 7—spray gun injection area, 8— Meter, 9—demineralized water pump, 10—denitration pump, 11—valve, 12—check valve, 13—filter, 14—static mixer, 15—compressed air main pipe, 16—cooling medium channel, 17— Reductant atomizer, 18—reductant main pipe, 19—denitration agent main pipe, 20—reductant branch pipe, 21—compressed air branch pipe, 22—reductant spray gun, 23—reversing valve, 24—denitration agent branch pipe, 25—Denitration agent branch, 26—Reducing agent branch, 27—Composite spray gun, 28—Denitrification agent spray gun, 29—Rotary kiln, 30—Preheater, 31—Return pipeline, 32—Overflow valve, 33—Compressed air Branch pipe, 34—calcining zone, 35—preheating zone, 36—cooling zone, 37—outlet, 38—feeding system, 39—upper suction beam, 40—denitration spray gun, 41—denitration beam, 42—combustion Beam, 43—lower suction beam, 44—denitration channel, 45—beam kiln.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and the accompanying drawings. The protection scope of the present invention is not limited to the embodiments, and any changes made by those skilled in the art within the scope defined in the claims also belong to the protection scope of the present invention.

Example 1

The lime kiln combined denitrification system of the present invention is shown in Fig. 1, comprises compressed air storage tank 1, reductant storage tank 2, demineralized water storage tank 3, denitration agent storage tank 4, waste water treatment device 5, static mixer 14 and lime kiln . The reducing agent in the reducing agent storage tank 2 is hydrogen, and the denitrating agent in the denitrating agent tank is ammonia water. The denitration agent storage tank is equipped with an automatic overflow pipeline and a discharge pipeline, and is connected with the wastewater treatment device. The lime kiln is a double-chamber kiln. As shown in Figure 2, the double-chamber kiln is provided with a channel 6 and a calcination zone 34, and the channel is provided with a reducing agent spray gun 22 and a denitration agent spray gun 28. The two kiln chambers are arranged in a ring. Reductant spray guns and denitrification agent sprays are arranged alternately, and the injection points of the reducing agent spray guns and denitrification agent spray guns are located in the flue gas channel of the double-chamber kiln, and the injection points of the reducing agent spray guns do not overlap with the injection points of the denitrification agent spray guns. The calcination zone 34 is provided with a composite spray gun 27, and the composite spray gun is equipped with a reducing agent atomizer 17, and the reducing agent atomizer is provided with a denitration agent inlet and a compressed air inlet, and the outlet of the reducing agent atomizer is connected to the cooling medium channel 16 of the spray gun . After atomization, the ammonia water enters the composite spray gun 27 through the cooling medium passage 16, and is sprayed into the spray area 7 of the composite spray gun. The reducing agent spray gun is provided with a reducing agent inlet and a compressed air inlet, the denitration agent spray gun is provided with a denitrification agent inlet and a compressed air inlet, and the reducing agent atomizer is provided with a denitrification agent inlet and a compressed air inlet. The compressed air storage tank 1 is connected to the compressed air inlets of the reductant spray guns, reductant atomizers and denitration agent spray guns respectively through the compressed air main pipe 15, the compressed air branch pipe 33 and the compressed air branch pipe 21. The reductant storage tank 2 is connected to the reductant inlet of each reductant spray gun through the reductant main pipe 18 , the reductant branch pipe 26 and the reductant branch pipe 20 , and the reductant main pipe is provided with a meter 8 . A reversing valve 23 is installed on the reducing agent branch pipe 26 to control the reversing operation of the reducing agent. The outlets of the desalted water storage tank and the denitrification agent storage tank are equipped with filters, and the desalted water storage tank is connected to the desalinated water pump through the filter. The desalted water pump outlet is divided into two paths through the check valve 12 and the valve 11, and one path passes through the meter 8 is connected to the static mixer 14, and one way is connected to the return inlet of the desalted water storage tank through the return line 31, and the return line is provided with a valve 11 and an overflow valve 32. The denitration agent storage tank is connected to the denitration pump 10 through a filter. The outlet of the denitration pump is divided into two paths through the check valve 12 and the valve 11, one path is connected to the static mixer 14 through the meter 8, and the other path is connected to the return inlet of the denitration agent storage tank through the return line 31, and the return line is provided with a valve 11 and overflow valve. The static mixer is connected to the denitration agent inlet of each denitration agent spray gun and reducing agent atomizer 17 through the denitration agent main pipe 19, the denitration agent branch pipe 25 and the denitration agent branch pipe 24. The denitration agent branch pipe 25 is equipped with a reversing valve 23 to control the reversing of ammonia water. There are two denitrification pumps and two desalinated water pumps, one for use and one for standby. The reducing agent branch pipe 20 , the compressed air branch pipe 21 and the denitration agent branch pipe 24 are equipped with a valve 11 and a check valve 12 .

After the ammonia water passes through the denitration agent main pipe and the denitration agent branch pipe, the three-way denitration agent branch pipe supplies the spray gun of the heat storage kiln chamber, and is atomized by the reducing agent atomizer and sprayed into the kiln chamber in the heat storage state through the cooling medium channel of the composite spray gun Inside, it is in countercurrent contact with the flue gas, and the atomized ammonia mist is also used to cool the spray gun. At this time, the compressed air is used as the atomizing medium for atomizing ammonia water. Combustion chamber composite spray gun stops supplying ammonia water and only supplies compressed air, which is used to cool the spray gun.

The calcination zone and channel are all equipped with denitration agent spray guns, or all are equipped with reducing agent spray guns, or both are installed at the same time. The composite spray gun is a single-layer or double-layer casing structure, which is set on the fuel spray gun. When the composite spray gun has a single-layer casing structure, it means that a ring of casing is set on the outer ring of the fuel spray gun, and the denitrification agent and/or reducing agent is sprayed from the ring pipe set on the outer ring of the fuel spray gun; when the composite spray gun has a double-layer casing structure , means that two rings of sleeves are set on the outer ring of the fuel spray gun, and the denitration agent and reducing agent are sprayed out from the ring pipes set in the outer ring of the fuel spray gun; the ring pipe can also be combined in the fuel spray gun, and the fuel injection pipe is a separate spray gun structure , the denitrification agent and/or reducing agent are injected together with the fuel. Or set the denitration agent spray gun/reductant spray gun separately, independent of the fuel spray gun, and position above the fuel spray gun, or below the fuel spray gun, so that the denitrification agent spray gun can extend to a deeper and higher temperature place. The denitration agent is atomized by compressed air and sprayed out with the fuel, or sprayed separately; the denitration agent spray gun and the reducing agent spray gun work under the condition of flue gas downstream or under the condition of flue gas countercurrent.

The combined denitrification system of the double chamber kiln is connected in parallel under the control of the PLC system, and works automatically according to the program. The process is as follows: (1) The ammonia water tanker is connected to the ammonia discharge pipeline, and the ammonia discharge pump is turned on. The ammonia water enters the denitration agent storage tank 4 after being filtered by the filter, The mass concentration of ammonia water in the denitrification tank is 20-25%. (2) The ammonia water in the denitration agent storage tank flows out due to the suction generated by the denitration pump, and after being filtered by the filter 13, it enters the denitrification pump and enters the main pipe of the denitrification agent. Enter static mixer 14 to mix, and the mass concentration of ammoniacal liquor after static mixer is 8-15%. The mixed and diluted low-concentration ammonia water enters the denitration agent main pipe 19 on the kiln. (3) The main denitration agent pipe on the kiln distributes the low-concentration ammonia water to the corresponding denitration agent branch pipe of the double chamber kiln, and the denitrification agent branch pipe distributes the ammonia water to the denitrification agent branch pipe, and enters the denitration agent spray gun located in the flue gas channel of the double chamber kiln. The compressed air is atomized and enters the kiln for denitrification. The two kiln chambers are operated in reverse, alternately performing calcination and heat storage. During the denitrification process of denitrification agent, compressed air is used as the atomization medium of ammonia water, and at the same time, it is used as the cooling medium for cooling the denitrification agent spray gun that stops supplying ammonia water during the reversing period. (4) During the reversing of the denitration agent branch pipe and the stop of supplying ammonia water, continue to supply compressed air to the denitrification agent spray gun. At this time, the compressed air is used to cool the denitrification agent spray gun. (5) When the working pressure of the denitration agent pipeline is higher than the pressure setting value of the overflow valve on the ammonia water return pipeline, the overflow valve opens, and the excess flow of ammonia water returns to the denitrification agent storage tank through the ammonia water return pipeline. (6) When the working pressure of the desalted water pipeline system is higher than the pressure setting value of the overflow valve on the desalted water return pipeline, the overflow valve opens, and the excess flow of desalted water returns to the desalted water storage tank through the desalted water return pipeline. (7) When the liquid level of the denitration agent storage tank of the ammonia water storage tank is higher than the maximum liquid level, the ammonia water will automatically overflow to the wastewater treatment device. In case of emergency, open the discharge pipeline at the bottom of the denitration agent storage tank, and discharge the ammonia water in the denitration agent storage tank and the upper pipeline of the kiln to the wastewater treatment device. (8) Flow metering devices are installed on the denitration agent main pipe and the desalinated water pipeline, which can monitor the flow of ammonia water and desalinated water in real time to achieve precise control of the concentration of ammonia water. (9) Install a coarse filter before the ammonia discharge pump, and a fine filter before the denitrification pump and the desalinated water pump to prevent debris from entering the system and prevent system blockage and equipment damage. Both the denitrification pump and the desalinated water pump use one for use and one for standby to prevent equipment damage and system overload, and ensure system safety and stability. (10) The overflow valve has the functions of constant pressure overflow, pressure stabilization, system unloading, and safety protection to ensure constant system pressure. (11) The reducing agent in the reducing agent storage tank enters the reducing agent main pipe due to the pressure difference, and after being measured by the flow metering device, it is distributed to the corresponding reducing agent branch pipe of the calcination chamber, and then distributed to the reducing agent branch pipe, enters the reducing agent spray gun, and sprays to Denitrification in the flue gas channel of the double chamber kiln. (12) During the reversing of the reducing agent branch pipe and the stop of reducing agent supply, the reducing agent spray gun starts to supply compressed air, and the compressed air is used to cool the reducing agent spray gun. The reducing agent denitrification system is used in conjunction with the denitrification agent denitrification system to improve the denitrification efficiency.

Example 2

Another embodiment of the present invention is shown in Figure 3, the lime kiln is a rotary kiln 29, and the rotary kiln includes a kiln head, a kiln tail and a preheater 30, and the preheater is connected to the kiln tail. Reductant spray gun 22 and denitration agent spray gun 28 are arranged at the kiln tail. The reducing agent spray gun is provided with a reducing agent inlet and a compressed air inlet, and the denitration agent spray gun is provided with a denitrification agent inlet and a compressed air inlet. The compressed air storage tank is respectively connected to the compressed air inlet of the reducing agent spray gun and the denitration agent spray gun and the compressed air main pipe 15, the compressed air 33 branch pipe and the compressed air branch pipe 21. The reducing agent storage tank 2 is connected to the reducing agent inlet of each reducing agent spray gun through the reducing agent main pipe 18 , the reducing agent branch pipe 26 and the reducing agent branch pipe 20 . Filters are installed at the outlets of the desalinated water storage tank and the denitrification agent storage tank. The desalted water storage tank is connected to the desalinated water pump through the filter. The desalted water pump outlet is divided into two paths through the check valve 12 and the valve 11. The water pump 9 and meter 8 are connected to the static mixer 14 , and one path is connected to the return inlet of the desalted water storage tank through the return line 31 . The denitration agent storage tank is connected to the denitration pump 10 through a filter. The outlet of the denitration pump is divided into two paths through the check valve 12 and the valve 11, one path is connected to the static mixer 14 through the denitration pump 10 and the meter 8, and the other path is connected to the return inlet of the denitration agent storage tank through the return line 31. The static mixer is connected to the denitration agent inlet of each denitration agent spray gun and reductant atomizer 17 through denitration agent main pipe 19, denitration agent branch pipe 25 and denitration agent branch pipe 24. The reducing agent in the reducing agent storage tank 2 is carbon monoxide. There are two denitrification pumps and two desalinated water pumps, one for use and one for standby. The operation of this embodiment is the same as that of Embodiment 1.

Example 3

Still another embodiment of the present invention is shown in FIG. 4 , the lime kiln is a beam kiln 45 , and the beam kiln includes a feeding system 38 , a kiln body and a discharge port 37 . The kiln body is provided with a preheating zone 35 , a calcining zone 34 and a cooling zone 36 . The preheating zone is provided with an upper suction beam 39, the lower part of the upper suction beam is provided with a denitrification beam 41, the calcining zone is provided with a combustion beam 42, and the cooling zone is provided with a lower suction beam 43. The upper suction beam is provided with a denitration spray gun 40, the lower suction beam and the denitration beam are provided with a denitration channel 44, the denitration spray gun and the denitration channel are provided with a denitration agent atomizer, and the denitration agent atomizer is provided with a denitrification agent inlet and a compressed air inlet . The desalinated water storage tank is connected to the static mixer 14 through the desalinated water pump and the meter 8, and the denitration agent storage tank is connected to the static mixer 14 through the denitrification pump 10 and the meter 8. The static mixer is connected to the denitrification atomizer of the denitrification spray gun 40 at the lower part of the upper suction beam, the denitrification channel of the denitrification beam and the denitrification channel 44 of the lower suction beam respectively through the main denitrification agent pipe 19, the denitrification agent branch pipe 25 and the denitrification agent branch pipe 24. Drug entrance. The compressed air storage tank 1 is respectively connected to the compressed air inlets of the denitration spray guns and the denitration atomizers of the denitration channels through the compressed air main pipe 15 , the compressed air branch pipe 33 and the compressed air branch pipe 21 .

After the ammonia water passes through the nitrate main pipe 19 and the denitrification branch pipe 25, it is respectively supplied to the denitrification spray gun at the lower part of the upper suction beam, the denitrification beam, and the denitrification branch pipe 24 corresponding to the denitrification channel of the lower suction beam, and is atomized by the denitrification atomizer. The denitrification spray gun, denitrification beam, and denitrification channel of the lower exhaust beam enter the preheating zone and cooling zone respectively, and are mixed with flue gas for denitrification. At this time, the compressed air is used as the atomization medium for atomizing ammonia water. When the denitrification spray gun, denitrification beam, and denitrification channel of the lower air extraction beam stop supplying ammonia water, the compressed air will continue to be supplied, and the compressed air is used as a cooling medium at this time.

Claims (10)

1. A lime kiln combined denitrification system, including compressed air storage tank (1), reducing agent storage tank (2), desalted water storage tank (3), denitrification agent storage tank (4), wastewater treatment device (5), The static mixer (14) and the lime kiln, the denitration agent storage tank is connected with the waste water treatment device; it is characterized in that: the lime kiln is provided with a reducing agent spray gun (22) and/or a denitrification agent spray gun (28), and the reducing agent The spray gun is provided with a reducing agent inlet and a compressed air inlet, and the denitration agent spray gun is provided with a denitrification agent inlet and a compressed air inlet; and compressed air branch pipes (21) are respectively connected to the compressed air inlets of the reducing agent spray guns and denitration agent spray guns; The branch pipe (20) is connected to the reducing agent inlet of each reducing agent spray gun, and the reducing agent main pipe is provided with a meter (8); the denitration agent storage tank is connected to the static Mixer, the desalted water storage tank (3) is connected to the static mixer (14) through the desalted water pump (9) and meter (8), and the static mixer passes through the denitration agent main pipe (19), denitration agent The branch pipe (25) and the denitration agent branch pipe (24) are connected to the denitration agent inlet of each denitration agent spray gun. 2. The lime kiln combined denitrification system according to claim 1, characterized in that: the lime kiln is a double-chamber kiln, a rotary kiln (29), a sleeve kiln, a beam kiln or an annular counter-fired kiln. 3. The lime kiln combined denitrification system according to claim 2, characterized in that: the double chamber kiln is provided with a calcination zone (34) and a channel (6), and the channel (6) is provided with a reducing agent spray gun (22 ) and/or denitrification spray guns (28), the reducing agent spray guns and denitrification spray guns are arranged annularly in the two kiln chambers of the double-chamber kiln; ) or composite spray gun (27), or any combination of denitration agent spray gun, reducing agent spray gun and composite spray gun, or denitrification agent spray gun, reducing agent spray gun and composite spray gun are set at the same time; composite spray gun is equipped with reducing agent atomizer, reducing agent The atomizer is provided with a denitration agent inlet and a compressed air inlet, and the outlet of the reducing agent atomizer is connected to the cooling medium channel (16) of the spray gun; ) and the denitration agent branch pipe (24) are connected to the denitration agent inlet of the reducing agent atomizer, and the compressed air storage tank (1) passes through the compressed air main pipe (15), the compressed air branch pipe (33) and the compressed air branch pipe (21 ) to the compressed air inlet of the reductant atomizer. 4. The lime kiln combined denitrification system according to claim 3, characterized in that: all of the calcining belts and passages are equipped with denitrification agent spray guns, or all of them are equipped with reducing agent spray guns, or both are installed at the same time, and the ratio of the two quantities can be adjusted arbitrarily , the total number of the two can be adjusted arbitrarily; the compound spray gun is a single-layer or double-layer casing structure, which is set on the fuel spray gun to spray out the denitrification agent and/or reducing agent; or set the denitrification agent spray gun/reductant spray gun separately, independent of the fuel The spray gun is located above the fuel spray gun or below the fuel spray gun, so that the denitrification agent spray gun can be extended to a deeper and higher temperature place; the denitrification agent is sprayed with the fuel after being atomized by compressed air, or sprayed separately; the denitrification agent The spray gun and the reducing agent spray gun work under the state of calcination or heat storage; the denitration agent spray gun and the reducing agent spray gun work under the condition of flue gas downstream or under the condition of flue gas countercurrent. 5. The lime kiln combined denitrification system according to claim 2, characterized in that: the rotary kiln (29) includes a kiln head, a kiln tail and a preheater (30), and the preheater is connected to the kiln tail; Reductant spray guns (22) and/or denitrification agent spray guns (28) are installed at the kiln tail; all denitrification agent spray guns, or all reducing agent spray guns, or both are installed at the kiln tail, and the ratio of the two numbers can be adjusted arbitrarily. The total number of them can be adjusted arbitrarily; the denitrification agent is atomized by compressed air and then sprayed out with the fuel, or sprayed out alone. 6. The lime kiln combined denitrification system according to claim 2, characterized in that: the beam kiln (45) is equipped with a preheating zone (35), a calcination zone (34) and a cooling zone (36), and the The preheating zone is provided with an upper suction beam (39), the lower part of the upper suction beam is provided with a denitrification beam (41), the calcining zone is provided with a combustion beam (42), and the cooling zone is provided with a lower suction beam. beam (43); the upper suction beam is provided with a denitration spray gun (40), and the lower suction beam and the denitration beam are provided with a denitration channel (44); the denitration spray gun (40) and the denitration channel (44) are provided with There is a denitrification agent atomizer, and the denitrification agent atomizer is provided with a denitrification agent inlet and a compressed air inlet; the static mixer is connected through a denitrification agent main pipe (19), a denitrification agent branch pipe (25) and a denitrification agent branch pipe (24) The denitrification agent inlet of the denitrification spray gun (40) at the lower part of the upper suction beam, the denitrification channel of the denitrification beam and the denitrification channel (44) of the lower suction beam; the compressed air storage tank (1) passes through the compressed air bus Pipe (15), compressed air branch pipe (33) and compressed air branch pipe (21) are respectively connected to the compressed air inlet of each denitration spray gun and the denitrification agent atomizer of the denitration channel. 7. The lime kiln combined denitration system according to claim 1, characterized in that: the outlets of the desalted water storage tank (3) and the denitrification agent storage tank (4) are provided with a filter (13), and the desalted water The storage tank (3) is connected to the demineralized water pump (9) through a filter, and the denitration agent storage tank is connected to the denitration pump (10) through a filter. 8. The lime kiln combined denitrification system according to claim 1, characterized in that: the desalinated water storage tank (3) and the denitrification agent storage tank (4) are respectively provided with return pipelines (31), and the desalination The outlet of the water pump (9) returns all the way to the desalted water storage tank through the return pipeline; the denitrification pump (10) is connected to the denitrification agent storage tank (4) through the return pipeline. 9. The lime kiln combined denitrification system according to claim 1, characterized in that: the denitrification agent branch pipe (25) is equipped with a reversing valve (23) to control the reversing of ammonia water; the reducing agent branch pipe (26) A reversing valve is installed on the top to control the reversing operation of the reducing agent. 10. The lime kiln combined denitrification system according to claim 1, characterized in that: the denitrification agent is ammonia water or urea or a mixture of the above two; the reducing agent is hydrogen, methane or carbon monoxide, or a mixture of the above gases , or carbon-containing reducing gas or liquid or solid or a mixture of the above substances.