Calcination system of corrugated plate type SCR denitration catalyst

Abstract

The corrugated plate type SCR denitration catalyst calcining system comprises a furnace chamber, and the furnace chamber is divided into an upper flow guide cavity on the upper side, a lower flow guide cavity on the lower side and a middle calcining cavity; the device further comprises a circulating fan and a circulating pipeline, the circulating fan is installed in the upper flow guide cavity, a first end and a second end are formed at the two ends of the circulating pipeline respectively, the first end communicates with the circulating fan, the second end communicates with the lower flow guide cavity, and the circulating fan is used for supplying air from the first end to the second end. A heating module is mounted at the middle section of the circulating pipeline; the energy-saving and environment-friendly stove further comprises a fresh air fan, the fresh air fan is connected with a fresh air pipeline, and the fresh air pipeline can introduce fresh air into the stove cavity through the fresh air fan. The furnace further comprises an exhaust fan, and the exhaust fan is communicated with the furnace cavity through an exhaust pipeline and used for exhausting air in the furnace cavity. In the calcining process, catalytic active components are fully thermally decomposed and activated, and the denitration performance of the product is improved.

Description

Technical Field

[0001] This invention relates to the field of SCR denitrification catalyst technology, and more specifically, to a calcination system for a corrugated plate type SCR denitrification catalyst. Background Technology

[0002] SCR (Selective Catalytic Reduction) is the most mature denitrification technology known to date. Currently, the most common catalyst forms in the denitrification field are honeycomb, flat-plate, and corrugated types. Corrugated denitrification catalysts use glass fiber as a substrate, which is hot-pressed into a support and then uniformly coated with catalytic active materials. Due to its unique preparation process, it possesses advantages such as high denitrification efficiency, light weight, high specific surface area, corrosion resistance, and strong thermal shock resistance. The calcination of the SCR catalyst is a crucial step in the production process, directly affecting the final denitrification effect. During calcination, it is necessary to ensure the discharge of organic matter from the catalyst and the waste gas generated from the pyrolysis of catalytic active components, maintaining the calcination temperature within a reasonable range to thermally decompose and activate the internal catalytic active components.

[0003] Therefore, a new solution is needed to address the calcination problem of corrugated plate SCR denitration catalysts. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a calcination system for a corrugated plate SCR denitrification catalyst.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A calcination system for a corrugated plate SCR denitration catalyst includes a furnace chamber, which is divided into an upper guide chamber on the upper side, a lower guide chamber on the lower side, and a calcination chamber in the middle.

[0007] It also includes a circulating fan and a circulating pipeline. The circulating fan is installed in the upper guide cavity. The two ends of the circulating pipeline form a first end and a second end, respectively. The first end is connected to the circulating fan, and the second end is connected to the lower guide cavity. The circulating fan is used to send air from the first end to the second end. A heating module is installed in the middle section of the circulating pipeline.

[0008] It also includes a fresh air fan, which is connected to a fresh air duct, and the fresh air duct can introduce fresh air into the furnace cavity through the fresh air fan;

[0009] It also includes an exhaust fan, which is connected to the furnace cavity through an exhaust duct to exhaust the air inside the furnace cavity.

[0010] The present invention is further configured such that a flow guide base is installed in the calcination chamber, the catalyst is placed in layers on the flow guide base, and the catalyst layers are separated by a partition frame; the catalyst has vertically oriented channels, and circulating hot air flows from bottom to top through the channels in the catalyst to heat and calcine the catalyst.

[0011] The present invention is further configured such that an upper uniform plate and a lower uniform plate are provided inside the furnace cavity, and the upper uniform plate and the lower uniform plate divide the furnace cavity into an upper guide cavity, a lower guide cavity and a calcination cavity.

[0012] The present invention is further configured such that the exhaust fan is connected to the upper guide cavity through an exhaust duct, and an exhaust anemometer is installed in the exhaust duct; and a fresh air anemometer is installed in the fresh air duct.

[0013] The present invention is further configured such that the fresh air duct is connected to a lower fresh air branch pipe and an upper fresh air branch pipe, one end of the lower fresh air branch pipe is a lower fresh air end connected to the lower guide cavity, and the lower fresh air branch pipe is equipped with a lower fresh air valve; one end of the upper fresh air branch pipe is an upper fresh air end connected to the upper guide cavity, and the upper fresh air branch pipe is equipped with an upper fresh air valve.

[0014] The present invention is further configured such that, during the process of supplying fresh air to the furnace cavity, the proportion of fresh air flowing from the lower fresh air branch pipe and the upper fresh air branch pipe is controlled according to the temperature inside the calcination cavity, and the proportion of fresh air input into the upper guide cavity and the lower guide cavity is controlled, thereby assisting in the temperature regulation inside the calcination cavity.

[0015] The auxiliary adjustment process includes the following steps:

[0016] Step 1: Obtain the theoretical temperature change curve inside the calcination chamber;

[0017] Step 2: The flow rate of the lower fresh air branch pipe is P(i), and the flow rate of the upper fresh air branch pipe is Q(i), where Q(i) = 1 - P(i):

[0018] Step 3: At each unit time interval, obtain the current theoretical temperature value T1(i) and detect the actual temperature value T2(i) inside the calcination chamber;

[0019] The initial value of i is 0, and each detection is recorded as i = i + 1;

[0020] Step 4: The actual difference between the theoretical temperature value T1(i) and the actual temperature value T2(i) is ΔT(i), where ΔT(i) = T2(i) - T1(i);

[0021] Step 4: Obtain the current allowable deviation threshold σ, where the current allowable temperature range is [T1(i)-σ, T1(i)+σ];

[0022] Step 5: Compare ΔT(i) with the currently allowed temperature range, and adjust the flow rates of the lower fresh air branch pipe and the upper fresh air branch pipe according to the relationship between ΔT(i) and the currently allowed temperature range;

[0023] Step 5 includes: Step 5a and Step 5b;

[0024] Step 5a: When ΔT(i) exceeds the currently allowed temperature range, enter the adjustment mode and adjust the flow rates of the lower fresh air branch pipe and the upper fresh air branch pipe;

[0025] If P(i) < P(0), increase the flow rate of the fresh air branch pipe, P(i + 1) = P(i) + k1, k1 = 5%;

[0026] If P(i) > P(0), decrease the flow rate of the fresh air branch pipe, P(i + 1) = P(i) - k1, k1 = 5%;

[0027] Step 5b: When ΔT(i) does not exceed the currently allowed temperature range, enter the steady state mode and maintain the flow rates of the lower fresh air branch pipe and the upper fresh air branch pipe; P(i + 1) = P(i).

[0028] Step 6: Repeat Steps 2 - 5 to perform steady state adjustment on the flow rates of the lower fresh air branch pipe and the upper fresh air branch pipe.

[0029] In Step 6, when entering the steady state mode three times continuously, perform initialization adjustment on the flow rate of the lower fresh air branch pipe. During the initialization adjustment process, if T2(i) > T1(i), increase the flow rate of the lower fresh air branch pipe. The adjusted flow rate of the fresh air branch pipe is P(i + 1), P(i + 1) = P(i) + k2; the initial value of the flow rate of the lower fresh air branch pipe is P(0), P(0) = 50%; k2 = 5%;

[0030] If T2(i) < T1(i), decrease the flow rate of the lower fresh air branch pipe. The adjusted flow rate of the fresh air branch pipe is P(i + 1), P(i + 1) = P(i) - k2; the initial value of the flow rate of the lower fresh air branch pipe is P(0), P(0) = 50%; k2 = 5%.

[0031] In summary, the present invention has the following beneficial effects:

[0032] By adopting the diversion base and the isolation rack, the catalyst module can be supported, so that there is a space for air circulation between the catalyst modules; combined with the hot air circulation, it can ensure that uniform hot air flows through each catalyst module, ensuring that the calcination effects of each catalyst are consistent.

[0033] The flow difference between fresh air intake and exhaust gas creates a pressure differential within the calcining furnace, facilitating the removal of organic matter from the catalyst and exhaust gases generated from the pyrolysis of catalytically active components. This helps stabilize the calcination environment within the calcination chamber. Furthermore, in conjunction with a nitrogen generator, the oxygen content within the calcination chamber can be controlled, ensuring effective calcination of the catalytic converter module. Additionally, during the supply of fresh air to the furnace chamber, the ratio of fresh air flowing from the lower and upper fresh air branch pipes, and the ratio of fresh air input to the upper and lower guide chambers, are controlled based on the temperature within the calcination chamber, thus providing auxiliary temperature regulation within the calcination chamber. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the calcination system of a corrugated plate SCR denitration catalyst in this embodiment;

[0035] Figure 2 This is a schematic diagram of the structure of the fresh air fan and fresh air duct in this embodiment. Figure 1 ;

[0036] Figure 3 This is a schematic diagram of the structure of the fresh air fan and fresh air duct in this embodiment. Figure 2 ;

[0037] Figure 4 The images show photographs of catalyst samples from each of Examples 1 and Comparative Example 1 in the calcination method of this embodiment. Parts A and B in the images represent Example 1, and parts C and D represent Comparative Example 1.

[0038] Reference numerals: Furnace cavity 1; Upper uniform plate 101; Lower uniform plate 102; Upper guide cavity 103; Lower guide cavity 104; Calcination cavity 105; Circulating fan 2; Exhaust fan 3; Exhaust duct 31; Exhaust anemometer 32; Fresh air fan 4; Circulating duct 5; First end 51; Second end 52; Heating module 53; Fresh air duct 6; Main air duct 60; Fresh air anemometer 61; Lower fresh air branch duct 62; Lower fresh air valve 621; Lower fresh air end 622; Branch anemometer 623; Upper fresh air branch duct 63; Upper fresh air valve 631; Upper fresh air end 632; Guide base 7; Isolation frame 71; Heat exchanger 8; Catalyst module 9. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This embodiment discloses a calcination system for a corrugated plate SCR denitration catalyst, referring to... Figure 1 , Figure 2 As shown, the furnace includes a furnace cavity 1. An upper uniform plate 101 and a lower uniform plate 102 are arranged in parallel inside the furnace cavity 1. The upper uniform plate 101 is close to the top of the furnace cavity 1, and the lower uniform plate 102 is close to the bottom of the furnace cavity 1. The upper uniform plate 101 and the lower uniform plate 102 divide the furnace cavity 1 into an upper guide cavity 103 on the upper side, a lower guide cavity 104 on the lower side, and a calcination cavity 105 in the middle.

[0041] Both the upper uniform plate 101 and the lower uniform plate 102 have several air guide holes to allow hot air to circulate. During the circulation process, hot air is input from the lower guide cavity 104, and after being uniformly circulated by the lower uniform plate 102, it forms a uniform upward airflow. The hot air flows through the calcination cavity 105, which heats and calcines the catalyst inside. Then, the hot air flows through the upper uniform plate 101 and enters the upper guide cavity 103. Through the circulating fan 2 and the circulating pipe 5, the hot air can circulate between the lower guide cavity 104, the calcination cavity 105, and the upper guide cavity 103, thus realizing hot air circulation.

[0042] The circulation pipe 5 has a first end 51 and a second end 52 at its two ends. The first end 51 is connected to the upper guide cavity 103, and the second end 52 is connected to the circulation fan 2 in the lower guide cavity 104. The circulation fan 2 is installed in the upper guide cavity 103; the air inlet side of the circulation fan 2 is connected to the upper guide cavity 103, and the air outlet side is connected to the first end 51 of the circulation pipe 5. The circulation fan 2 can deliver air from the first end 51 to the second end 52. Furthermore, a heating module 53 is installed in the middle section of the circulation pipe 5. The heating module 53 can heat the circulating air during the calcination process to generate hot air at the required temperature.

[0043] In this embodiment, the circulation flow rate of the circulating fan 2 is greater than 20,000 m³ / s. 3 / h, through large-flow circulation, helps to uniform heat, and the air velocity at the top of the calcination chamber 105 (i.e. near the upper uniform plate 101) is not less than 1m / s. The air velocity at this position is used to roughly judge whether the air circulation volume in the furnace meets the requirements.

[0044] In addition, the calcination system of this embodiment is also equipped with a fresh air fan 4 and an exhaust fan 3. The fresh air fan 4 can introduce fresh air into the furnace chamber 1, while the exhaust fan 3 can exhaust the waste gas generated during calcination in the furnace chamber 1. By controlling the fresh air volume and the exhaust volume, the pressure of the furnace chamber 1 can be maintained to form the required internal and external pressure difference.

[0045] During the calcination process, the exhaust duct 31 can exhaust the hot air from the furnace chamber 1 to the outside, and the fresh air duct 6 can introduce fresh air into the furnace chamber 1. By controlling the flow rates of the exhaust duct 31 and the fresh air duct 6, the pressure inside the furnace chamber 1 can be controlled. For example, if the calcination parameters require maintaining a positive pressure, the positive pressure inside the calcination chamber 105 must not be lower than 200 Pa, that is, it must be higher than the external atmospheric pressure by 200 Pa. For example, if the calcination parameters require maintaining a negative pressure, the negative pressure inside the calcination chamber 105 must not be lower than 150 Pa, that is, it must be lower than the external atmospheric pressure by 150 Pa.

[0046] In this embodiment, the exhaust fan 3 is connected to the upper guide cavity 103 via the exhaust duct 31. The exhaust fan 3 can draw air from the upper guide cavity 103, thereby enabling the exhaust gas from the furnace to be discharged. An exhaust anemometer 32 is installed in the exhaust duct 31 to obtain the exhaust status by measuring the wind speed. During the exhaust process, controlling the power of the exhaust fan 3 will change the exhaust wind speed, which is used as the control parameter.

[0047] In this embodiment, the fresh air fan 4 is connected to a fresh air duct 6, and a fresh air anemometer 61 is installed in the fresh air duct 6. The fresh air anemometer 61 can obtain the air volume of fresh air entering the furnace. Furthermore, the air outlet of the fresh air duct 6 forms two branches, namely a lower fresh air branch 62 and an upper fresh air branch 63. One end of the lower fresh air branch 62 is connected to the lower guide cavity 104 (lower fresh air end 622), which can deliver fresh air into the lower guide cavity 104; one end of the upper fresh air branch 63 is connected to the upper guide cavity 103 (upper fresh air end 632), which can deliver fresh air into the upper guide cavity 103.

[0048] In addition, a lower fresh air valve 621 is installed on the lower fresh air branch duct 62; an upper fresh air valve 631 is installed on the upper fresh air branch duct 63. Both the lower fresh air valve 621 and the upper fresh air valve 631 can regulate the airflow. For example, both valves can control the airflow and have a multi-level adjustment structure, each with 10 or more levels. During adjustment, for example, if the opening range of the two valves is controlled to be the same, the airflow of the two lines will be approximately 50%, and the total airflow will be 100%.

[0049] During the adjustment process, the overall air intake of the fresh air duct 6 is kept stable by controlling the power of the fresh air fan 4, that is, the reading of the fresh air anemometer 61 remains stable. In order to better control the air volume ratio between the lower fresh air branch duct 62 and the upper fresh air branch duct 63, a branch anemometer 623 can be installed in the lower fresh air branch duct 62 to accurately obtain the air volume of this duct. By comparing the readings of the branch anemometer 623 and the fresh air anemometer 61, the air volume ratio P flowing through the lower fresh air branch duct 62 can be obtained.

[0050] In addition, to control the oxygen content inside the furnace, the calcination system of this embodiment also includes a nitrogen generator. The nitrogen generator is connected to the air inlet of the fresh air fan 4, meaning that the fresh air input to the fresh air fan 4 comes from the nitrogen generator. This allows for control of the ratio of air to nitrogen in the fresh air, thereby controlling the oxygen content inside the calcination chamber 105. During the calcination process, the oxygen content is detected by an online trace oxygen analyzer, ensuring that the oxygen content inside the calcination furnace does not exceed 5%, and nitrogen is used to maintain the oxygen balance.

[0051] During the calcination process, a flow guide base 7 is placed inside the calcination chamber 105. Catalyst modules 9 are layered on the flow guide base 7, and each layer of catalyst modules 9 is separated by an isolation frame 71. This allows for the placement of multiple layers of catalyst modules 9 in the calcination chamber 105, and ensures stable hot air flow to the catalyst modules 9 during the flow guide process. When the catalyst is placed, its internal flow channels are oriented vertically, consistent with the direction of the rising hot air flow. The hot air flow can pass through the internal flow channels of the catalyst module for heating and calcination.

[0052] This embodiment also provides a calcination method for a corrugated plate SCR denitration catalyst, which uses the calcination system described above for calcination; the theoretical temperature change curve during the calcination process is set according to design requirements, and the heating temperature of the heating module 53 is designed according to the theoretical temperature change curve.

[0053] The heating and cooling methods during the calcination process are as follows: First, heat the corrugated plate SCR catalyst from room temperature to 450-550℃, with a heating rate not exceeding 1℃ / min; during the heating process, multiple heat preservation stages can be set.

[0054] After reaching the predetermined temperature, calcine at a constant temperature for 2-5 hours;

[0055] After the heating is complete, the temperature is lowered. The cooling rate should not exceed 5℃ / min. When the temperature drops below 80℃, the furnace door is opened.

[0056] Example 1

[0057] The corrugated plate SCR denitration catalyst product was calcined using the above-mentioned calcination system. The catalyst product was a 2.7mm pitch corrugated plate SCR catalyst. The specific calcination method is as follows:

[0058] (1) During the calcination process, the catalyst product is placed on the guide base 7 of the calcination chamber 105, and the two catalyst modules are isolated by the isolation frame 71 and the furnace door is closed.

[0059] (2) Turn on the circulating fan 2, the fresh air fan 4, and the exhaust fan 3. Adjust the flow rate of the exhaust fan 3 to 200 m³ / h. 3 / h, adjust the flow rate of fresh air fan 4 to 1300m³ / h. 3 / h, the furnace pressure eventually stabilized at approximately a positive pressure of 200Pa; the flow rate of the hot air circulating fan 2 was adjusted to 18000m³ / h. 3 / h, after the gas flows through the catalyst, the average gas velocity at the top is about 2m / s;

[0060] (3) Turn on the nitrogen generator and use the high-purity nitrogen produced by the nitrogen generator as the fresh air source to control the oxygen content in the calcination chamber 105. The oxygen detector shows that the oxygen content in the furnace is about 5%.

[0061] (4) A stepped heating and cooling calcination method is adopted. The calcination temperature and time are set through the electrical control cabinet, and the heating program is started to begin heating. The specific calcination temperature and time steps are as follows:

[0062] Table 1 Stepped calcination curves

[0063]

[0064] Example 2

[0065] The corrugated plate SCR denitration catalyst product was calcined using the above-mentioned calcination system. The catalyst product was a 4.8mm pitch corrugated plate SCR catalyst. The specific calcination method is as follows:

[0066] (1) During the calcination process, the catalyst product is placed on the guide base 7 of the calcination chamber 105 and isolated between the two catalyst modules by the isolation frame 71, and the furnace door is closed; the arrangement of the catalyst modules is the same as in Example 1.

[0067] (2) Turn on the circulating fan 2, the fresh air fan 4, and the exhaust fan 3. Adjust the flow rate of the exhaust fan 3 to 1300 m³ / h. 3 / h, adjust the flow rate of fresh air fan 4 to 300m³ / h. 3 / h, the furnace pressure eventually stabilized at approximately a negative pressure of 150Pa; the flow rate of the hot air circulating fan 2 was adjusted to 18000m³ / h. 3 / h, after the gas flows through the catalyst, the average gas velocity at the top is about 2m / s;

[0068] (3) Turn on the nitrogen generator and use the high-purity nitrogen produced by the nitrogen generator as the fresh air source to control the oxygen content in the calcination chamber 105. The oxygen detector shows that the oxygen content in the furnace is about 5%.

[0069] (4) A stepped heating and cooling calcination method is adopted. The calcination temperature and time are set through the electrical control cabinet, and the heating program is started to begin heating. The specific calcination temperature and time steps are as follows:

[0070] Table 2 Stepped calcination curves

[0071]

[0072] Example 3

[0073] The corrugated plate SCR denitration catalyst product was calcined using the above-mentioned calcination system. The catalyst product was a 3.2mm pitch corrugated plate SCR catalyst. The specific calcination method is as follows:

[0074] (1) During the calcination process, the catalyst product is placed on the guide base 7 of the calcination chamber 105 and isolated between the two catalyst modules by the isolation frame 71, and the furnace door is closed; the arrangement of the catalyst modules is the same as in Example 1.

[0075] (2) Turn on the circulating fan 2, the fresh air fan 4, and the exhaust fan 3. Adjust the flow rate of the exhaust fan 3 to 1300 m³ / h. 3 / h, adjust the flow rate of fresh air fan 4 to 300m³ / h. 3 / h, the furnace pressure eventually stabilized at approximately a negative pressure of 150Pa; the flow rate of the hot air circulating fan 2 was adjusted to 18000m³ / h. 3 / h, after the gas flows through the catalyst, the average gas velocity at the top is about 2m / s;

[0076] (3) Turn on the nitrogen generator and use the high-purity nitrogen produced by the nitrogen generator as the fresh air source to control the oxygen content in the calcination chamber 105. The oxygen detector shows that the oxygen content in the furnace is about 5%.

[0077] (4) A stepped heating and cooling calcination method is adopted. The calcination temperature and time are set through the electrical control cabinet, and the heating program is started to begin heating. The specific calcination temperature and time steps are as follows:

[0078] Table 3 Stepped calcination curves

[0079]

[0080] Comparative Example 1

[0081] The corrugated plate SCR denitration catalyst product, which is a 2.7mm pitch corrugated plate SCR catalyst, was calcined using a conventional calcination system. The specific calcination method is as follows:

[0082] (1) During the calcination process, the catalyst product is placed on the guide base 7 of the calcination chamber 105 and isolated between the two catalyst modules by the isolation frame 71, and the furnace door is closed; the arrangement of the catalyst modules is the same as in Example 1.

[0083] (2) Turn on the exhaust fan and fresh air fan normally, and adjust the flow rate to 1300 m³ / h. 3 / h, no pressure inside the furnace; adjust the flow rate of the hot air circulating fan to 18000m³ / h. 3 / h, the average gas velocity at the top after the gas flows through the catalyst is approximately 2m / s; it does not have a nitrogen generator, maintaining a normal oxygen content of 21% inside the furnace;

[0084] (3) A unique stepped heating and cooling calcination method is adopted. The calcination temperature and time are set through the electrical control cabinet, and the heating program is started to begin heating. The specific calcination temperature and time steps are as follows:

[0085] Table 4 Stepped calcination curves

[0086]

[0087] Comparative Example 2

[0088] The corrugated plate SCR denitration catalyst product was calcined using the above-mentioned calcination system. The catalyst product was a 2.7mm pitch corrugated plate SCR catalyst. The specific calcination method is as follows:

[0089] (1) During the calcination process, the catalyst product is placed on the guide base 7 of the calcination chamber 105 and isolated between the two catalyst modules by the isolation frame 71, and the furnace door is closed; the arrangement of the catalyst modules is the same as in Example 1.

[0090] (2) Turn on the hot air circulation fan, fresh air fan, and exhaust fan. Adjust the exhaust fan flow rate to 200 m³ / h. 3 / h, adjust the fresh air fan flow rate to 1300m³ / h. 3 / h, the furnace pressure eventually stabilized at a positive pressure of 200Pa; the flow rate of the hot air circulating fan was adjusted to 18000m³ / h. 3 / h, after the gas flows through the catalyst, the average gas velocity at the top is about 2m / s;

[0091] (3) Turn on the nitrogen generator and use the high-purity nitrogen produced by the nitrogen generator as the fresh air source to control the oxygen content in the calcination chamber 105. The oxygen detector shows that the oxygen content in the furnace is about 5%.

[0092] (4) A non-step heating curve was adopted, and the calcination curve was set as shown in the table below:

[0093] Table 5 Non-stepwise calcination curves

[0094]

[0095] Evaluation conditions for the denitrification performance of the catalyst of this invention: space velocity 45000 h⁻¹ -1 The reaction temperature is 320℃, and the inlet NO is... x 60mg / m 3The O2 content is 3%, the H2O content is 6.3%, and the ammonia-nitrogen molar ratio is 1:1. The compressive strength of the catalyst of this invention was tested according to the standard "Technical Specification for Testing Corrugated Plate Denitrification Catalysts" GB / T 39703-2020.

[0096] The denitrification efficiency and axial compressive strength of the calcined catalysts of each embodiment and comparative example were tested, and the interlayer bonding strength and appearance color of the catalysts were compared. The results are shown in Table 6.

[0097] Table 6 Performance test results of the examples and comparative examples

[0098]

[0099] As shown in Table 6 above, comparing Example 1 and Comparative Example 1 reveals that although the same calcination curve was used, different calcination furnace parameters resulted in variations in furnace pressure, oxygen content, and wind speed, leading to significant differences in the catalyst's denitrification efficiency and axial compressive strength. The calcination process and method provided by this invention can significantly improve the denitrification efficiency and compressive strength of corrugated plate SCR catalysts.

[0100] Comparing Example 1 and Comparative Example 2, it was found that using the same calcination system and furnace parameter settings, but with different calcination heating curves, resulted in significant performance differences. The stepped calcination curve can significantly improve the denitrification efficiency and axial compressive strength of the corrugated plate SCR catalyst. Furthermore, the sample in Example 1 showed no blackening, while the sample in Comparative Example 2 showed internal blackening, indicating that the stepped calcination method allows for the complete decomposition and removal of internal organic matter.

[0101] As can be seen from Table 6 above, the calcination method of the present invention can effectively calcine various corrugated plate SCR catalysts with different pitches, and the method has a certain degree of universality.

[0102] This embodiment also discloses a calcination method for a corrugated plate SCR denitration catalyst, which uses the above-mentioned calcination device and, based on the above-mentioned calcination method, supplements and adjusts the temperature fluctuations in the furnace.

[0103] Multiple temperature sensors are installed inside the calcination chamber 105. Based on the required temperature change curve, the heating module 53 can automatically control the temperature. However, during the calcination process, the temperature inside the furnace will fluctuate due to fluctuations in external temperature, heating voltage, and other factors. These fluctuations have a particularly significant impact during the heating and cooling processes.

[0104] After fluctuations, the heating module 53, temperature sensor, and temperature control system can automatically regulate the temperature in the calcination chamber 105 to a steady state, so that the temperature in the calcination chamber 105 returns to the required temperature.

[0105] In this embodiment, during the process of supplying fresh air to the furnace chamber 1, the ratio of fresh air flowing from the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63 is controlled according to the temperature inside the calcination chamber 105, and the ratio of fresh air input to the upper guide chamber 10 and the lower guide chamber 104 is controlled to assist in the temperature regulation inside the calcination chamber 105.

[0106] The specific adjustment method is as follows: when the temperature inside the calcination chamber 105 is slightly higher than the theoretical temperature, the fresh air flow rate of the lower fresh air branch pipe 62 is appropriately increased, while the fresh air flow rate of the upper fresh air branch pipe 63 is reduced to maintain the total fresh air volume unchanged. More fresh air with lower temperature can be directly introduced into the lower guide chamber 104, which can slightly reduce the temperature of the hot air directly flowing into the calcination chamber 105, thereby appropriately reducing the temperature of the calcination chamber 105 and supplementing the temperature adjustment inside the calcination chamber 105.

[0107] Conversely, when the temperature inside the calcination chamber 105 is slightly lower than the theoretical temperature, the fresh air flow rate of the lower fresh air branch pipe 62 is appropriately reduced, while the fresh air flow rate of the upper fresh air branch pipe 63 is increased to maintain the total fresh air volume unchanged. The lower-temperature fresh air can be directly introduced into the lower guide chamber 104 less, and the temperature of the hot air directly flowing into the calcination chamber 105 will be slightly increased, thereby appropriately increasing the temperature of the calcination chamber 105 and supplementing the temperature regulation inside the calcination chamber 105.

[0108] In this embodiment, the method for assisting temperature regulation within the calcination chamber 105 during the calcination process includes the following steps:

[0109] Step 1: Obtain the theoretical temperature change curve inside the calcination chamber 105, which will give you the theoretical temperature value at each corresponding time point and the temperature deviation range at each corresponding time point.

[0110] Step 2: The flow rate of the lower fresh air branch pipe 62 is P(i), and the flow rate of the upper fresh air branch pipe 63 is Q(i), Q(i) = 1 - P(i): Specifically, the flow rates of the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63 can be expressed as percentages.

[0111] When i=0, P(0) is the initial flow rate of the lower fresh air branch pipe 62. Under normal circumstances, both P(0) and Q(0) are 50%, which allows for a certain amount of adjustment for both upward and downward adjustment.

[0112] Step 3: During the supplementary adjustment process, the temperature inside the calcination chamber 105 is dynamically monitored at each unit time interval; the current theoretical temperature value T1(i) is obtained, and the actual temperature value T2(i) inside the calcination chamber 105 is detected;

[0113] The initial value of i is 0. Each time a detection record is made, it is denoted as i = i + 1. That is, at the time point of the first detection record, the theoretical temperature value T1(1) can be obtained according to the theoretical temperature change curve; the actual temperature value T2(1) inside the calcination chamber 105 is detected and obtained; during each subsequent detection, T1(2), T2(2), T1(3), T2(3), T1(4), T2(4) …… are obtained respectively.

[0114] Step 4: After each detection, obtain the actual difference ΔT(i) between the theoretical temperature value T1(i) and the actual temperature value T2(i), ΔT(i) = T2(i) - T1(i);

[0115] Step 4: According to the theoretical temperature change curve and the preset theoretical parameters, obtain the currently allowed deviation threshold σ, and the currently allowed temperature range is [T1(i) - σ, T1(i) + σ];

[0116] Step 5: Compare ΔT(i) with the currently allowed temperature range, and adjust the flow rates of the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63 according to the relationship between ΔT(i) and the currently allowed temperature range;

[0117] Step 5a: When ΔT(i) exceeds the currently allowed temperature range, enter the adjustment mode and adjust the flow rates of the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63;

[0118] If P(i) < P(0), then increase the flow rate of the fresh air branch pipe 62. The flow rate of the fresh air branch pipe 62 in the next detection cycle is P(i + 1), and P(i + 1) = P(i) + k1. Generally, k1 can be 5%.

[0119] If P(i) > P(0), then decrease the flow rate of the fresh air branch pipe 62. The flow rate of the fresh air branch pipe 62 in the next detection cycle is P(i + 1), and P(i + 1) = P(i) - k1. Generally, k1 can be 5%.

[0120] Step 5b: When ΔT(i) does not exceed the currently allowed temperature range, enter the steady state mode and maintain the flow rates of the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63; the flow rate of the fresh air branch pipe 62 in the next detection cycle is P(i + 1), maintaining the value of the previous detection cycle, that is, P(i + 1) = P(i).

[0121] Step 6: Repeat steps 2 - 5 to perform steady state adjustment on the flow rates of the lower fresh air branch pipe 62 and the upper fresh air branch pipe 63.

[0122] During the loop detection process in step 6, when entering the steady state mode three times consecutively, it indicates that the current temperature control system is in a stable operating state. The temperature can be controlled within an appropriate range through the regulation of the temperature control system, and there is no need to supplement and adjust with fresh air. At this time, the flow distribution of the fresh air system can be initialized, and the flow rate of the lower fresh air branch pipe 62 can be initialized to gradually restore the flow rate of the fresh air branch pipe 62 to the initial value P(0). For example, if the flow rate P(0) of the fresh air branch pipe 62 is 50%, it is gradually restored to 50%.

[0123] During the initialization adjustment process,

[0124] If T2(i) > T1(i), increase the flow rate of the lower fresh air branch pipe 62. The adjusted flow rate of the fresh air branch pipe 62 is P(i + 1), and P(i + 1) = P(i) + k2; the initial value of the flow rate of the lower fresh air branch pipe 62 is P(0), and P(0) = 50%;

[0125] If T2(i) < T1(i), decrease the flow rate of the lower fresh air branch pipe 62. The adjusted flow rate of the fresh air branch pipe 62 is P(i + 1), and P(i + 1) = P(i) - k2; the initial value of the flow rate of the lower fresh air branch pipe 62 is P(0), and P(0) = 50%;

[0126] Specifically, k2 represents the amount of each initialization adjustment. k2 is 0.5 times to 1.5 times of k1. The smaller k2 is, the smaller the adjustment amplitude each time. k2 can also be 5%.

[0127] During the loop detection process in step 6, when entering the adjustment mode three times consecutively, it indicates that the current compensation adjustment amplitude is not sufficient to compensate for the temperature, and the compensation adjustment amplitude needs to be increased. The value of k1 can be increased. For example, k1 can be increased, and k1 can be increased to 8% - 10%;

[0128] Moreover, when P(i) ≥ 95% or P(i) ≤ 5%, the compensation adjustment mode is entered. In the compensation adjustment mode, the total fresh air volume and the exhaust air can be increased or decreased simultaneously. On the one hand, it can maintain the pressure in the furnace basically unchanged, and on the other hand, it can adjust the total fresh air volume, thereby further improving the effect of fresh air auxiliary adjustment.

[0129] The steps of the compensation adjustment mode include:

[0130] Step S1: Obtain the total fresh air volume X(i, j) input into the furnace chamber 1, obtain the exhaust air volume Y(i, j) discharged from the furnace chamber 1, and obtain the air pressure value in the furnace chamber 1; the initial value of j is 0, and each compensation adjustment is recorded as j = j + 1;

[0131] Step S2: When P(i)≥95%, it indicates that the air intake compensation of the lower fresh air branch 62 is close to the maximum value under the current state. In the subsequent auxiliary adjustment process, the air intake of the lower fresh air branch 62 may not meet the requirements of the auxiliary adjustment. Therefore, the total fresh air volume can be appropriately increased. The total fresh air volume after adjustment is X(i,j+1), X(i,j+1)=X(i,j)·(1+k3);

[0132] When P(i)≤5%, it indicates that the air intake compensation of the lower fresh air branch 62 is close to the minimum value under the current state. In the subsequent auxiliary adjustment process, the air intake of the lower fresh air branch 62 may not meet the requirements of the auxiliary adjustment. Therefore, the total fresh air volume can be appropriately reduced. The total fresh air volume after adjustment is X(i,j+1), X(i,j+1)=X(i,j)·(1-k3);

[0133] Specifically, the value of K3 can generally be 20% to 30%, which means it can adjust 20% to 30% of the total fresh air volume.

[0134] Step S3: Adjust the exhaust volume of the furnace chamber 1. By balancing the intake and exhaust volumes, the air pressure in the furnace chamber 1 is maintained within the threshold range of the air pressure value, thus completing the compensation adjustment.

[0135] During the cyclic detection process in step 6, if the steady-state mode is entered three times consecutively, it indicates that the current temperature control system is operating stably. At this time, the total fresh air volume X(i,j) discharged from furnace cavity 1, after adjustment, differs from the initial value X(i,0). Therefore, the total fresh air volume discharged from furnace cavity 1 is reset and adjusted gradually to its initial state. Each adjustment can be 0.2 times k3 to 0.5 times k3, restoring the preset air volume parameters.

[0136] Furthermore, referring to Figure 3 As shown, a heat exchanger 8 is installed between the exhaust duct 31 and the fresh air end 632 of the fresh air branch duct 63. The heat exchanger 8 can exchange heat between the exhaust duct 31 and the fresh air end 632 of the fresh air branch duct 63. During the exhaust process of the exhaust duct 31, the fresh air introduced into the fresh air end 632 can be preheated through the heat exchanger 8; at the same time, the temperature of the exhaust from the exhaust duct 31 is lower, which can carry away part of the cold air input, thereby reducing the impact of the fresh air on the cooling of the furnace cavity and further supplementing the effect of the fresh air auxiliary regulation.

[0137] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A calcination system for a corrugated plate type SCR denitration catalyst, characterized in that, It includes a furnace cavity (1), which is divided into an upper guide cavity (103) on the upper side, a lower guide cavity (104) on the lower side and a calcination cavity (105) in the middle; It also includes a circulating fan (2) and a circulating pipe (5). The circulating fan (2) is installed in the upper guide cavity (103). The two ends of the circulating pipe (5) are respectively formed as a first end (51) and a second end (52). The first end (51) is connected to the circulating fan (2), and the second end (52) is connected to the lower guide cavity (104). The circulating fan (2) is used to send air from the first end (51) to the second end (52). A heating module (53) is installed in the middle section of the circulating pipe (5). It also includes a fresh air fan (4), which is connected to a fresh air duct (6), and the fresh air duct (6) can introduce fresh air into the furnace cavity (1) through the fresh air fan (4); It also includes an exhaust fan (3), which is connected to the furnace chamber (1) through an exhaust pipe (31) to exhaust the air in the furnace chamber (1).

2. The calcination system for a corrugated plate SCR denitration catalyst according to claim 1, characterized in that: The calcination chamber (105) is equipped with a flow guide base (7), and the catalyst is placed in layers on the flow guide base (7), and the catalyst layers are separated by an isolation frame (71); the catalyst has vertically oriented channels, and the circulating hot air flows from bottom to top through the channels in the catalyst to heat and calcine the catalyst.

3. The calcination system for a corrugated plate SCR denitration catalyst according to claim 1, characterized in that, The furnace cavity (1) is provided with an upper uniform plate (101) and a lower uniform plate (102), which divide the furnace cavity (1) into an upper guide cavity (103), a lower guide cavity (104) and a calcination cavity (105).

4. The calcination system for a corrugated plate SCR denitration catalyst according to claim 1, characterized in that, The exhaust fan (3) is connected to the upper guide cavity (103) through the exhaust pipe (31), and the exhaust pipe (31) is equipped with an exhaust anemometer (32); the fresh air pipe (6) is equipped with a fresh air anemometer (61).

5. The calcination system for a corrugated plate SCR denitration catalyst according to claim 4, characterized in that, The fresh air duct (6) is connected to a lower fresh air branch pipe (62) and an upper fresh air branch pipe (63). One end of the lower fresh air branch pipe (62) is a lower fresh air end (622) connected to the lower guide cavity (104), and the lower fresh air branch pipe (62) is equipped with a lower fresh air valve (621). One end of the upper fresh air branch pipe (63) is an upper fresh air end (632) connected to the upper guide cavity (103), and the upper fresh air branch pipe (63) is equipped with an upper fresh air valve (631).

6. The calcination system for a corrugated plate SCR denitration catalyst according to claim 5, characterized in that: During the process of supplying fresh air to the furnace cavity (1), the ratio of fresh air flowing from the lower fresh air branch pipe (62) and the upper fresh air branch pipe (63) is controlled according to the temperature inside the calcination cavity (105), and the ratio of fresh air input to the upper guide cavity (10) and the lower guide cavity (104) is controlled to assist in the temperature regulation inside the calcination cavity (105).

7. The calcination system for a corrugated plate SCR denitration catalyst according to claim 6, characterized in that: The auxiliary adjustment process includes the following steps: Step 1: Obtain the theoretical temperature change curve inside the calcination chamber (105); Step 2: The flow rate of the lower fresh air branch pipe (62) is P(i), and the flow rate of the upper fresh air branch pipe (63) is Q(i), where Q(i) = 1 - P(i): Step 3: Every interval of the unit time period, obtain the current theoretical temperature value T1(i), and detect the actual temperature value T2(i) in the calcination chamber (105); The initial value of i is 0, and each detection record is denoted as i = i + 1; Step 4: The actual difference ΔT(i) between the theoretical temperature value T1(i) and the actual temperature value T2(i), ΔT(i) = T2(i) - T1(i); Step 4: Obtain the current allowable deviation threshold σ, and the current allowable temperature range is [T1(i) - σ, T1(i) + σ]; Step 5: Compare ΔT(i) with the current allowable temperature range, and adjust the flow rates of the lower fresh air branch pipe (62) and the upper fresh air branch pipe (63) according to the relationship between ΔT(i) and the current allowable temperature range; Step 6: Repeat Steps 2 - 5 to perform a steady - state adjustment on the flow rates of the lower fresh air branch pipe (62) and the upper fresh air branch pipe (63).

8. The calcination system for a corrugated plate SCR denitration catalyst according to claim 7, characterized in that: Step 5 includes: Step 5a and Step 5b; Step 5a: When ΔT(i) exceeds the current allowable temperature range, enter the adjustment mode and adjust the flow rates of the lower fresh air branch pipe (62) and the upper fresh air branch pipe (63); If P(i) < P(0), then increase the flow rate of the fresh air branch pipe (62), P(i + 1) = P(i) + k1, k1 = 5%; If P(i) > P(0), then decrease the flow rate of the fresh air branch pipe (62), P(i + 1) = P(i) - k1, k1 = 5%; Step 5b: When ΔT(i) does not exceed the current allowable temperature range, enter the steady - state mode and maintain the flow rates of the lower fresh air branch pipe (62) and the upper fresh air branch pipe (63); P(i + 1) = P(i).

9. The calcination system for a corrugated plate SCR denitration catalyst according to claim 8, characterized in that: In Step 6, when entering the steady - state mode three times continuously, perform an initialization adjustment on the flow rate of the lower fresh air branch pipe (62). During the initialization adjustment process, if T2(i) > T1(i), increase the flow rate of the lower fresh air branch pipe (62), and the adjusted flow rate of the fresh air branch pipe (62) is P(i + 1), P(i + 1) = P(i) + k2; the initial value of the flow rate of the lower fresh air branch pipe (62) is P(0), P(0) = 50%; k2 = 5%.

10. The calcination system for a corrugated plate SCR denitration catalyst according to claim 9, characterized in that: If T2(i) < T1(i), decrease the flow rate of the lower fresh air branch pipe (62), and the adjusted flow rate of the fresh air branch pipe (62) is P(i + 1), P(i + 1) = P(i) - k2; the initial value of the flow rate of the lower fresh air branch pipe (62) is P(0), P(0) = 50%; k2 = 5%.

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