SNCR (selective non-catalytic reduction) and SCR (selective catalytic reduction) combined denitration device for calcining flue gas treatment

Abstract

The invention discloses an SNCR (selective non-catalytic reduction) and SCR (selective catalytic reduction) combined denitration device for calcining flue gas treatment, which mainly relates to the technical field of denitration, and comprises a urea converter, the urea converter is communicated with an ammonia water preparation device, the ammonia water preparation device is communicated with a multipurpose water tank, the ammonia water preparation device is communicated with an ammonia water storage tank, and the ammonia water storage tank is connected with a metering distribution device. The metering distribution device is connected with two large grid-shaped spray guns arranged on the SNCR large boiler, another pipeline is connected with a small grid-shaped spray gun arranged on the SNCR small boiler, the SNCR large boiler is connected with a flue gas pipe, the SNCR small boiler is connected with an SCR reactor through a secondary treatment pipe, the bottom of the SCR reactor is provided with a dust remover, and the dust remover is connected with a waste box; the flue gas denitration device can perform denitration treatment on flue gas twice, so that the denitration efficiency is improved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of denitration, and in particular to an SNCR+SCR combined denitration device for calcination flue gas treatment. Background Art

[0002] In the development of modern industry, harmful gases are often produced during calcination operations in some carbon industries, such as in power plants, steel and other industries. The production of these gases is inevitable, and they cannot be directly discharged into the air after production, which will cause huge pollution. In order to solve this problem, manufacturers now often use denitrification equipment for treatment and then discharge, and the treatment technology is generally SNCR and SCR. The above two have their own advantages and disadvantages. SNCR saves money but has low efficiency, and SCR is efficient but expensive.

[0003] Both denitrification methods still have a certain degree of incomplete nitrate treatment. For example, during SNCR denitrification, there will be deposited scale and slag at the bottom of the boiler. The deposition in the slag ditch will affect the temperature of the boiler. Temperature is an important factor affecting denitrification, which directly affects the efficiency of the reaction and the degree of denitrification. In addition, the existing equipment can only rely on external addition of denitrification raw materials. In view of these difficulties, it is necessary to design a device that can improve the denitrification efficiency and solve the above difficulties. Summary of the invention

[0004] 1. Technical issues to be resolved In view of the above-mentioned problems, the present invention needs to provide a SNCR+SCR combined denitrification device for calcination flue gas treatment, which can improve the denitrification rate. When the two methods are combined, it can not only add denitrification raw materials externally, but also have the function of preparing denitrification raw materials by itself. The operation during denitrification is more free from the limitation of materials, and the dust and dirt at the bottom of the boiler can be cleaned to ensure the denitrification efficiency.

[0005] (II) Technical solution In view of the above technical problems, the present invention provides an SNCR+SCR combined denitrification device for calcination flue gas treatment, comprising a urea converter, the urea converter is used to make ammonia water, the urea converter is connected to an ammonia water preparation device, the ammonia water preparation device is connected to a multi-use water tank, the ammonia water preparation device is connected to an ammonia water storage tank, the ammonia water storage tank is connected to a metering and distributing device, the metering and distributing device is connected to two large grid-shaped spray guns arranged on a large SNCR boiler by a pipeline, another pipeline is connected to a small grid-shaped spray gun arranged on a small SNCR boiler, the large SNCR boiler is connected to a flue gas pipe, the large SNCR boiler and the small SNCR boiler are connected by large and small connecting pipes, the small SNCR boiler is connected to an SCR reactor by a secondary treatment pipe, a dust collector is arranged at the bottom of the SCR reactor, and the dust collector is connected to a waste box; cleaning brushes are arranged in both the large SNCR boiler and the small SNCR boiler.

[0006] Furthermore, the urea converter includes four spaces: an inlet, a dissolution layer, a gas-liquid layer, and a bottom reaction layer. A baffle cover is rotatably provided between the inlet and the dissolution layer, an upper cover is flipped on the top of the inlet, and an annular water gun is fixedly installed between the inlet and the dissolution layer and below the baffle cover. The annular water gun is connected to a multi-use water tank; stirring teeth are rotatably provided in the dissolution layer.

[0007] Furthermore, a cover rod is fixedly connected horizontally to the upper cover, a pinion is fixedly arranged on the cover rod, the pinion and the small rack form a gear rack match, the small rack is fixedly mounted on the special-shaped plate, a cylinder is also arranged between the special-shaped plate and the elliptical space, and a short inclined surface and a long slope are arranged at the end of the special-shaped plate.

[0008] Furthermore, a rotating shaft is fixedly connected to the blocking cover, and the rotating shaft is rotatably mounted on the urea converter. A torsion spring is provided between the rotating shaft and the urea converter. A cylindrical rod is fixedly mounted on the rotating shaft, and the cylindrical rod cooperates with the short inclined surface and the long slope.

[0009] Furthermore, the dissolution layer and the bottom reaction layer are connected by a transfer pump pipe assembly, and the gas-liquid layer and the bottom reaction layer are connected by a bent pipe. A gas-liquid separator is provided in the gas-liquid layer, and a gas transferor is provided in the space between the gas-liquid separator and the gas-liquid layer and connected to the ammonia water preparation device; the ammonia water preparation device is provided with a terminal ammonia water pipe, which is connected to an ammonia water pump pipe assembly, which is connected to an ammonia water storage tank, and a check valve is provided in the terminal ammonia water pipe, and an external valve pipe assembly is connected to the terminal ammonia water pipe; the bottom reaction layer is connected to a lower return water pipe, and an upper return water pipe is connected in the space from the gas-liquid separator to the bottom of the gas-liquid layer, and the lower return water pipe and the upper return water pipe are mixed and connected to a recovery pump pipe assembly, and the recovery pump pipe assembly is connected to a multi-use water tank; a purification pipe is also connected between the ammonia water preparation device and the multi-use water tank.

[0010] Furthermore, the multi-use water tank is provided with a pure water external pipe, a pure water left port, and a pure water right port. There are corresponding chambers below the pure water left port and the pure water right port respectively. After the water is introduced from the pure water external pipe, it enters the chamber below from the pure water left port and the pure water right port respectively. A cleaning connection port is provided in the chamber below the pure water left port. The cleaning connection port is connected with a cleaning pipe, which is connected to a cleaning pump. A water pipe is provided on the cleaning pump to connect with the SNCR large boiler. The cleaning pump is also connected with a cleaning water outlet pipe to connect with the SNCR small boiler. The recovery pump-pipe assembly is connected to the return water connection port, and the prepared water enters the chamber where the pure water right port is located from the return water inlet.

[0011] Furthermore, two upper and lower first raised plates are provided on one side of the large SNCR boiler, and a second raised plate is provided on the other side of the large SNCR boiler and located between the two first raised plates; two large grid-shaped spray guns, one is provided below the second raised plate, and the other is provided between the two first raised plates and close to the upper first raised plate; the height of the large SNCR boiler is lower than that of the small SNCR boiler.

[0012] Furthermore, an inclined baffle is fixedly installed in the SNCR small boiler, and an angle of 23.94 degrees is formed between the inclined baffle and the top of the SNCR small boiler. The small grid-shaped spray gun is arranged on the opposite side of the inclined baffle and is higher than the inclined baffle. The gas in the SNCR small boiler enters the SCR reactor, and the SCR reactor is provided with an SCR catalyst.

[0013] Furthermore, a large cleaning brush is rotatably installed at the bottom of the SNCR large boiler, and a small cleaning brush is rotatably installed at the bottom of the SNCR small boiler. The large cleaning brush extends to the shaft outside the SNCR large boiler and is fixedly installed with a cleaning double-groove pulley. The small cleaning brush extends to the shaft outside the SNCR small boiler and is fixedly connected to the cleaning pulley. A cleaning belt is sleeved on the cleaning double-groove pulley and the cleaning pulley. A cleaning transmission belt is also sleeved on the cleaning double-groove pulley and connected to the power device.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention is provided with a urea converter, which can be converted multiple times to prepare ammonia water, and has a sealing function during preparation to prevent urea solid, liquid, and gas from splashing and causing harm to human health; 2. The present invention is provided with a multi-use water tank, which can supply water required for preparing ammonia water, and can also recycle water, and has pure water for denitrification and pure water for cleaning boilers, and has complete functions; 3. The present invention is provided with a SNCR large boiler and a SNCR small boiler, and the two boilers are respectively provided with a first raised plate, a second raised plate, an inclined baffle, a large grid-shaped spray gun, and a small grid-shaped spray gun, and the raised plate and the inclined baffle are used to block the flue gas when the flue gas is introduced. Block the flue gas, and then use the spray gun to spray water for denitrification, which can minimize the escape of harmful flue gas and treat the nitrate in the flue gas to the maximum extent; 4. The present invention is equipped with a large cleaning brush and a small cleaning brush to clean the bottom of the two boilers, and rinse with water to remove the dust and dirt at the bottom of the boiler to avoid the dust and dirt affecting the temperature in the boiler, thereby ensuring the normal use of the boiler and improving the degree of denitrification; 5. The present invention belongs to a technology for calcination flue gas treatment in the carbon industry, which can be applied in power plants, steel and other industries. When in use, ammonia water can be sprayed at the front end (SNCR large boiler) and less or no spraying can be done at the back end (SNCR small boiler), which can greatly reduce ammonia escape while ensuring high denitrification efficiency, with good operating stability and simple operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 It is a schematic diagram from another angle of the present invention.

[0017] Figure 3 It is a partial first angle schematic diagram of the denitration mechanism of the present invention.

[0018] Figure 4 It is a partial second angle schematic diagram of the denitration mechanism of the present invention.

[0019] Figure 5 It is a partial third angle schematic diagram of the denitration mechanism of the present invention.

[0020] Figure 6 for Figure 5 Section view at AA in the middle.

[0021] Figure 7 It is a partial schematic diagram of the denitration mechanism of the present invention from the fourth angle.

[0022] Figure 8 for Figure 7 Cross-sectional view at BB in the middle.

[0023] Fig. 9 for Figure 3 A local enlarged schematic diagram of A1 in the figure.

[0024] Fig.10 It is a partial fifth angle schematic diagram of the denitration mechanism of the present invention.

[0025] Fig.11 It is a partial sixth angle schematic diagram of the denitration mechanism of the present invention.

[0026] Fig.12 It is a partial schematic diagram of the seventh angle of the denitrification mechanism of the present invention.

[0027] Fig.13 for Fig.12 Sectional view at CC.

[0028] Fig.14 It is a schematic diagram of a multi-use water tank of the present invention.

[0029] Figure numbers: 1-denitrification mechanism; 101-urea converter; 102-ammonia preparation device; 103-multi-use water tank; 104-ammonia storage tank; 105-SNCR large boiler; 106-SNCR small boiler; 107-SCR reactor; 108-waste box; 109-upper cover; 110-cover rod; 111-small rack; 112-small gear; 113-cylinder; 114-special-shaped plate; 114-1-short slope; 114-2-long slope; 115-stirring motor; 116-transfer pump pipe assembly; 11 7-elliptical space; 118-gas transfer device; 119-recovery pump pipe assembly; 120-external valve pipe assembly; 121-water supply pump; 122-bend pipe; 123-upper layer return pipe; 124-lower layer return pipe; 125-purification pipe; 126-terminal ammonia pipe; 127-ammonia pump pipe assembly; 128-rotating shaft; 129-blocking cover; 130-torsion spring; 131-inlet; 132-dissolving layer; 133-gas-liquid layer; 134-gas-liquid separator; 135-bottom reaction layer; 136-stirring pulley; 137- agitating drive belt; 138- agitating teeth; 139- check ball; 140- check spring; 141- annular water gun; 142- air compressor; 143- metering and distributing device; 144- flue gas pipe; 145- large metering pipe; 146- large discharge pipe; 147- small discharge pipe; 148- dust collector; 149- dust removal pipe; 150- secondary treatment pipe; 151- small metering pipe; 152- large and small connecting pipes; 153- cleaning pipe; 154- cleaning pump; 155- cleaning water outlet pipe; 156- cleaning pulley; 157- Cleaning belt; 158-cleaning double groove pulley; 159-cleaning transmission belt; 160-cleaning main pulley; 161-cleaning motor; 162-SCR catalyst; 163-small grid-shaped spray gun; 164-oblique baffle; 165-first raised plate; 166-second raised plate; 167-large grid-shaped spray gun; 168-large cleaning brush; 169-small cleaning brush; 170-pure water left inlet; 171-pure water right inlet; 172-return water inlet; 173-return water connection port; 174-pure water external pipe; 175-cleaning connection port. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific embodiments. The present invention is explained by means of the illustrative embodiments and descriptions of the present invention, but is not intended to be limiting of the present invention.

[0031] Example: Figure 1-Figure 14 The SNCR+SCR combined denitrification device for calcination flue gas treatment shown in the figure includes a denitrification mechanism 1, which includes a urea converter 101 and a waste box 108. The urea converter 101 is used to produce ammonia water, and the waste box 108 is a fixed base of the present invention and can also have the function of receiving waste.

[0032] The urea converter 101 includes four spaces, namely, an inlet 131, a dissolution layer 132, a gas-liquid layer 133, and a bottom reaction layer 135. A baffle 129 is rotatably provided between the inlet 131 and the dissolution layer 132, an upper cover 109 is flipped on the top of the inlet 131, and an annular water gun 141 is fixedly installed between the inlet 131 and the dissolution layer 132 and below the baffle 129. The annular water gun 141 is connected to the multi-use water tank 103; stirring teeth 138 are rotatably provided in the dissolution layer 132.

[0033] A stirring pulley 136 is fixedly mounted on the stirring teeth 138 , another stirring pulley 136 is fixedly mounted on the stirring motor 115 , a stirring transmission belt 137 is sleeved on the two stirring pulleys 136 , and the stirring motor 115 is fixedly mounted on the urea converter 101 .

[0034] A heating device is provided at the bottom of the dissolving layer 132, specifically, it is provided at the solid area with oblique lines below the stirring teeth 138 in the figure. The heating device is a device in the prior art, which utilizes a heating tube and is powered on for heating.

[0035] A cover rod 110 is fixedly connected to the upper cover 109 in a horizontal position, and the cover rod 110 is rotatably mounted on the urea converter 101. A pinion 112 is fixedly arranged on the cover rod 110, and the pinion 112 forms a gear-rack match with a small rack 111. The small rack 111 is fixedly mounted on a special-shaped plate 114. Two support rods are arranged on the special-shaped plate 114, and the two support rods are slidably mounted on an elliptical space 117. The elliptical space 117 is fixedly arranged on the urea converter 101. The elliptical space 117 is used to accommodate a baffle 129. The support rods on the special-shaped plate 114 should avoid the baffle 129 so that the baffle 129 can be opened and closed. A cylinder 113 is also arranged between the special-shaped plate 114 and the elliptical space 117. The special-shaped plate 114 is fixedly connected to the movable end of the cylinder 113, and the cylinder 113 is fixedly mounted on the elliptical space 117. A short inclined surface 114-1 and a long slope 114-2 are arranged at the end of the special-shaped plate 114.

[0036] A rotating shaft 128 is fixedly connected to the blocking cover 129, and the rotating shaft 128 is rotatably mounted on the urea converter 101. A torsion spring 130 is provided between the rotating shaft 128 and the urea converter 101. One end of the torsion spring 130 is fixedly mounted on the rotating shaft 128, and the other end is fixedly mounted on the urea converter 101, so that the rotating shaft 128 can rotate and reset. A cylindrical rod is fixedly mounted on the rotating shaft 128, and the cylindrical rod cooperates with the short inclined surface 114-1 and the long slope 114-2.

[0037] The annular water gun 141 is connected to the water supply pump 121, and the water supply pump 121 is fixedly connected to the chamber of the multi-use water tank 103 located below the left pure water outlet 170 by a pipeline to obtain pure water.

[0038] The dissolution layer 132 is connected to the bottom reaction layer 135 by a transfer pump pipe assembly 116 to directly transfer the melted urea liquid to the bottom. The bottom reaction layer 135 is also a hydrolysis reaction mechanism with a catalyst placed inside. The gas-liquid layer 133 is connected to the bottom reaction layer 135 by a bend pipe 122. After the hydrolysis reaction, the bend pipe 122 is used to pass into the gas-liquid layer 133 for gas-liquid separation.

[0039] A gas-liquid separator 134 is provided in the gas-liquid layer 133, a gas transfer device 118 is provided in the space between the gas-liquid separator 134 and the gas-liquid layer 133, and the gas transfer device 118 is connected to the ammonia water preparation device 102, and the ammonia water preparation device 102 is provided with a terminal ammonia water pipe 126, and the terminal ammonia water pipe 126 is connected to the ammonia water pump pipe assembly 127, and the ammonia water pump pipe assembly 127 is connected to the ammonia water storage tank 104, and a check valve is provided in the terminal ammonia water pipe 126, and an external valve pipe assembly is connected to the terminal ammonia water pipe 126. 120, the external delivery valve pipe assembly 120 is used to transport ammonia from the outside; the bottom reaction layer 135 is connected with a lower return pipe 124, the space from the gas-liquid separator 134 to the bottom of the gas-liquid layer 133 is connected with an upper return pipe 123, the lower return pipe 124 and the upper return pipe 123 are mixed and connected to the recovery pump pipe assembly 119, and the recovery pump pipe assembly 119 is connected to the multi-use water tank 103; a purification pipe 125 is also connected between the multi-use water tank 103 and the ammonia water preparation device 102.

[0040] The check valve includes a check ball 139 and a check spring 140. The check spring 140 is fixedly mounted on the terminal ammonia pipe 126. The check ball 139 is fixedly mounted on the small end of the check spring 140. The function of the check valve is to allow only the prepared ammonia gas to be sent to the ammonia storage tank 104.

[0041] The multi-use water tank 103 is provided with a pure water external pipe 174, a pure water left port 170, and a pure water right port 171. The pure water external pipe 174 is used to connect pure water from the outside. There are chambers corresponding to the lower parts of the pure water left port 170 and the pure water right port 171. The pure water right port 171 and the return water inlet 172 are located above the same chamber. After the water is introduced from the pure water external pipe 174, it enters the lower chamber from the pure water left port 170 and the pure water right port 171 respectively. A cleaning connection port 175 is provided in the square chamber, and a cleaning pipe 153 is connected to the cleaning connection port 175, and the cleaning pipe 153 is connected to the cleaning pump 154. The cleaning pump 154 ​​is provided with a water pipe connected to the SNCR large boiler 105, and the cleaning pump 154 ​​is also connected to a cleaning water outlet pipe 155 connected to the SNCR small boiler 106; the recovery pump pipe assembly 119 is connected to the return water connection port 173, and the prepared water enters the chamber where the pure water right outlet 171 is located from the return water inlet 172.

[0042] An air compressor 142 is connected to the ammonia storage tank 104, and the air compressor 142 is connected to the metering and distributing device 143. The metering and distributing device 143 is connected to two large grid-shaped spray guns 167 installed on the SNCR large boiler 105 through a pipeline, and another pipeline is connected to a small grid-shaped spray gun 163 installed on the SNCR small boiler 106. The SNCR large boiler 105 is connected to a flue gas pipe 144, and the SNCR large boiler 105 and the SNCR small boiler 106 are connected by large and small connecting pipes 152.

[0043] Two upper and lower first raised plates 165 are provided on one side of the SNCR large boiler 105, and a second raised plate 166 is provided on the other side of the SNCR large boiler 105 and located between the two first raised plates 165, and two large grid-shaped spray guns 167, one is provided below the second raised plate 166, and the other is provided between the two first raised plates 165 and close to the upper first raised plate 165; the height of the SNCR large boiler 105 is lower than that of the SNCR small boiler 106.

[0044] An inclined baffle 164 is fixedly installed in the SNCR small boiler 106, and an angle of 23.94 degrees is formed between the inclined baffle 164 and the top of the SNCR small boiler 106. A small grid-shaped spray gun 163 is arranged on the opposite side of the inclined baffle 164 and is higher than the inclined baffle 164. The gas in the SNCR small boiler 106 enters the SCR reactor 107, and an SCR catalyst 162 is arranged in the SCR reactor 107.

[0045] The SNCR small boiler 106 is connected to the SCR reactor 107 via a secondary treatment pipe 150 . A dust collector 148 is provided at the bottom of the SCR reactor 107 , and the dust collector 148 is connected to the waste box 108 .

[0046] A large cleaning brush 168 is rotatably installed at the bottom of the SNCR large boiler 105, and a small cleaning brush 169 is rotatably installed at the bottom of the SNCR small boiler 106. The large cleaning brush 168 extends to the shaft outside the SNCR large boiler 105 and is fixedly installed with a cleaning double-groove pulley 158. The small cleaning brush 169 extends to the shaft outside the SNCR small boiler 106 and is fixedly connected to the cleaning pulley 156. A cleaning belt 157 is sleeved on the cleaning double-groove pulley 158 and the cleaning pulley 156. A cleaning drive belt 159 is also sleeved on the cleaning double-groove pulley 158 and connected to the power unit.

[0047] The power device includes a cleaning motor 161, which is fixedly mounted on the waste box 108. The output shaft of the waste box 108 is fixedly connected to the cleaning main pulley 160. The cleaning main pulley 160 and the cleaning double-groove pulley 158 are sleeved with a cleaning transmission belt 159.

[0048] The large SNCR boiler 105 is connected to a large drain pipe 146, and the small SNCR boiler 106 is connected to a small drain pipe 147. Both the large drain pipe 146 and the small drain pipe 147 are provided with valves, and the ends of the large drain pipe 146 and the small drain pipe 147 are connected to a waste box 108 for discharging waste.

[0049] Working principle of the present invention: Urea and ammonia water can both act as restoring agents for denitrification. The present invention has the function of directly adding ammonia water from the external delivery valve pipe assembly 120 to the ammonia water storage tank 104 for use and making ammonia water by oneself.

[0050] When ammonia water needs to be prepared, urea is added into the urea converter 101. Under normal circumstances, the upper cover 109 is in an open state and the baffle 129 is in a closed state. After the urea is added, it accumulates on the baffle 129. After the urea is added, the cylinder 113 is started to contract, driving the special-shaped plate 114 to descend. The small rack 111 and the small gear 112 form a match to drive the cover rod 110 and the upper cover 109 to rotate, and the upper cover 109 is closed. At the same time, when the special-shaped plate 114 descends, the short inclined surface 114-1 pushes the cylindrical rod of the rotating shaft 128, so that the rotating shaft 128 and the baffle 129 rotate. When the baffle 129 rotates, the urea is pushed and falls into the dissolution layer 132.

[0051] During the gradual movement, the long slope 114-2 will cooperate with the cylindrical rod to completely rotate the blocking cover 129 to one side, and the urea will be completely pushed down. At this time, the upper cover 109 is in a closed state, which can prevent liquid splashing and the generation of unpleasant gases that affect human health. The water supply pump 121 is started to pump pure water out from the annular water gun 141, and then the stirring motor 115 is used to drive the stirring pulley 136 to rotate, and the stirring pulley 136 drives the stirring teeth 138 to rotate, so that the urea and water are stirred to fully dissolve the urea, and at the same time, the water mixture is heated to accelerate the dissolution.

[0052] After the dissolution is completed, the stirring is stopped and the urea solution will be transported to the bottom reaction layer 135 by the transfer pump pipe assembly 116, where it will interact with the water molecules under the action of the catalyst, causing changes in the molecular structure of the urea to generate ammonia and carbon dioxide, while the liquid water will be pumped back into the multi-use water tank 103 by the return water pipe 124 and the recovery pump pipe assembly 119 below, and will mainly enter the multi-use water tank 103 from the return water connection port 173 and the return water inlet 172.

[0053] The generated hydrogen and carbon dioxide will form a mixed gas with water, and enter the gas-liquid layer 133 from the bottom reaction layer 135 through the curved pipe 122. Under the action of the gas-liquid separator 134, the ammonia will be separated and reach the upper layer, and enter the ammonia water preparation device 102 through the gas transferor 118, while the liquid water will re-enter the multi-use water tank 103 from the upper return pipe 123 and the recovery pump pipe assembly 119 for reuse.

[0054] The ammonia gas entering the ammonia water preparation device 102 reacts with the pure water transported in the multi-use water tank 103 to obtain pure ammonia water, which is finally input into the ammonia water storage tank 104 for storage under the action of the ammonia water pump pipe assembly 127.

[0055] When it is necessary to denitrify the flue gas, start the air compressor 142 to extract the ammonia water, which is then distributed using the metering and distributing device 143 and connected to the flue gas from the flue gas pipe 144. After the flue gas enters the SNCR large boiler 105, due to the obstruction of the second raised plate 166, the flue gas will gather under the SNCR large boiler 105. At this time, a large grid-shaped spray gun 167 is used to spray ammonia water for denitrification. A portion of the flue gas gradually goes up and reaches between the two first raised plates 165. The large grid-shaped spray gun 167 between the two first raised plates 165 sprays ammonia water again. Another portion of the flue gas will enter the SNCR small boiler 106 from the large and small connecting pipes 152. Under the cover of the inclined baffle 164, it is sprayed using the small grid-shaped spray gun 163 to improve the denitrification efficiency.

[0056] The remaining flue gas enters the SCR reactor 107 from the secondary treatment pipe 150, reacts under the action of the SCR catalyst 162, and undergoes secondary treatment to finally obtain denitrified flue gas and dust. At this time, the dust collector 148 is started to discharge it from the dust removal pipe 149 into the waste box 108. The water-dust mixture in the previous step can be discharged into the waste box 108 through the small discharge pipe 147 and the large discharge pipe 146 respectively.

[0057] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A SNCR+SCR combined denitrification device for calcination flue gas treatment, characterized in that: The invention comprises a urea converter (101), the urea converter (101) is used to produce ammonia water, the urea converter (101) is connected to an ammonia water preparation device (102), the ammonia water preparation device (102) is connected to a multi-use water tank (103), the ammonia water preparation device (102) is connected to an ammonia water storage tank (104), the ammonia water storage tank (104) is connected to a metering and distributing device (143), the metering and distributing device (143) is connected to two large grid-shaped spray guns (167) arranged on a SNCR large boiler (105) by a pipeline, and another pipeline is connected to a small grid-shaped spray gun (163) arranged on a SNCR large boiler (105). A flue gas pipe (144) is connected to the CR small boiler (106) and the SNCR large boiler (105); the SNCR large boiler (105) and the SNCR small boiler (106) are connected via large and small connecting pipes (152); the SNCR small boiler (106) is connected to the SCR reactor (107) via a secondary treatment pipe (150); a dust collector (148) is provided at the bottom of the SCR reactor (107); and the dust collector (148) is connected to the waste box (108); cleaning brushes are provided inside the SNCR large boiler (105) and the SNCR small boiler (106).

2. The SNCR+SCR combined denitrification device for calcination flue gas treatment according to claim 1, characterized in that: The urea converter (101) comprises four spaces, namely an inlet (131), a dissolving layer (132), a gas-liquid layer (133), and a bottom reaction layer (135), wherein a blocking cover (129) is rotatably provided between the inlet (131) and the dissolving layer (132), an upper cover (109) is flipped on the top of the inlet (131), an annular water gun (141) is fixedly installed between the inlet (131) and the dissolving layer (132) and below the blocking cover (129), and the annular water gun (141) is connected to a multi-use water tank (103); and stirring teeth (138) are rotatably provided in the dissolving layer (132).

3. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 2 is characterized in that: A cover rod (110) is fixedly connected to the upper cover (109) in a horizontal manner. A pinion gear (112) is fixedly arranged on the cover rod (110). The pinion gear (112) and a small rack (111) form a gear-rack match. The small rack (111) is fixedly mounted on a special-shaped plate (114). A cylinder (113) is further arranged between the special-shaped plate (114) and the elliptical space (117). A short inclined surface (114-1) and a long slope (114-2) are arranged at the end of the special-shaped plate (114).

4. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 3 is characterized in that: A rotating shaft (128) is fixedly connected to the blocking cover (129), and the rotating shaft (128) is rotatably mounted on the urea converter (101). A torsion spring (130) is provided between the rotating shaft (128) and the urea converter (101). A cylindrical rod is fixedly mounted on the rotating shaft (128), and the cylindrical rod cooperates with the short inclined surface (114-1) and the long inclined surface (114-2).

5. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 2, characterized in that: The dissolving layer (132) and the bottom reaction layer (135) are connected by a transfer pump pipe assembly (116), and the gas-liquid layer (133) and the bottom reaction layer (135) are connected by a bent pipe (122). A gas-liquid separator (134) is provided in the gas-liquid layer (133), and a gas transfer device (118) is provided in the space between the gas-liquid separator (134) and the gas-liquid layer (133) and is connected to the ammonia water preparation device (102); the ammonia water preparation device (102) is provided with a terminal ammonia water pipe (126), and the terminal ammonia water pipe (126) is connected to the ammonia water pump pipe assembly (127), and the ammonia water pump pipe assembly (127) is connected to the ammonia water storage tank ( The ammonia water pipe (126) is connected to the bottom reaction layer (135), a check valve is provided in the terminal ammonia water pipe (126), and an external valve pipe assembly (120) is connected to the terminal ammonia water pipe (126); the bottom reaction layer (135) is connected to the lower return pipe (124), the space from the gas-liquid separator (134) to the bottom of the gas-liquid layer (133) is connected to the upper return pipe (123), the lower return pipe (124) and the upper return pipe (123) are mixed and connected to the recovery pump pipe assembly (119), and the recovery pump pipe assembly (119) is connected to the multi-use water tank (103); a purification pipe (125) is also connected between the ammonia water preparation device (102) and the multi-use water tank (103).

6. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 5, characterized in that: The multi-use water tank (103) is provided with a pure water external pipe (174), a pure water left port (170), and a pure water right port (171). There are chambers corresponding to the lower parts of the pure water left port (170) and the pure water right port (171). After water enters the pure water external pipe (174), it enters the lower chamber from the pure water left port (170) and the pure water right port (171). A cleaning connection port (175) is provided in the chamber below the pure water left port (170). A cleaning pipe (153) is connected to the cleaning pump (154), the cleaning pipe (153) is connected to the cleaning pump (154), a water pipe is provided on the cleaning pump (154) and is connected to the SNCR large boiler (105), and a cleaning water outlet pipe (155) is also connected to the cleaning pump (154) and is connected to the SNCR small boiler (106); the recovery pump pipe assembly (119) is connected to the return water connection port (173), and the prepared water enters the chamber where the pure water right port (171) is located from the return water inlet (172).

7. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 1, characterized in that: Two upper and lower first raised plates (165) are provided on one side of the large SNCR boiler (105); a second raised plate (166) is provided on the other side of the large SNCR boiler (105) and is located between the two first raised plates (165); two large grid-shaped spray guns (167), one is provided below the second raised plate (166), and the other is provided between the two first raised plates (165) and close to the upper first raised plate (165); the height of the large SNCR boiler (105) is lower than that of the small SNCR boiler (106).

8. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 7, characterized in that: An inclined baffle (164) is fixedly installed in the SNCR small boiler (106), and an angle of 23.94 degrees is formed between the inclined baffle (164) and the top of the SNCR small boiler (106). A small grid-shaped spray gun (163) is arranged on the opposite side of the inclined baffle (164) and is higher than the inclined baffle (164). The gas in the SNCR small boiler (106) enters the SCR reactor (107), and an SCR catalyst (162) is arranged in the SCR reactor (107).

9. The SNCR+SCR combined denitration device for calcination flue gas treatment according to claim 8, characterized in that: A large cleaning brush (168) is rotatably mounted on the bottom of the SNCR large boiler (105), and a small cleaning brush (169) is rotatably mounted on the bottom of the SNCR small boiler (106). The large cleaning brush (168) extends to the shaft outside the SNCR large boiler (105) and is fixedly mounted with a cleaning double-groove pulley (158). The small cleaning brush (169) extends to the shaft outside the SNCR small boiler (106) and is fixedly connected to a cleaning pulley (156). A cleaning belt (157) is sleeved on the cleaning double-groove pulley (158) and the cleaning pulley (156). A cleaning transmission belt (159) is also sleeved on the cleaning double-groove pulley (158) and is connected to a power device.

Images