Cremation Exhaust Gas Purification System and Purification Method

Abstract

The present invention provides a cremation tail gas purification system and a purification method. The purification system includes: a fan, a combustion device, a quenching device, an adsorption and dust removal device, a denitration device, and a washing device. The fan is provided with a cremation tail gas inlet and a cremation tail gas outlet; the combustion device is provided with a first feed inlet and a combustion tail gas outlet, and the first feed inlet is communicated with the cremation tail gas outlet; the quenching device is provided with a combustion tail gas inlet and a cooling gas outlet, and the combustion tail gas inlet is connected to the combustion tail gas outlet; the adsorption and dust removal device is provided with a cooling gas inlet and a primary purified gas outlet, and the cooling gas inlet is communicated with the cooling gas outlet; the denitration device is provided with a primary purified gas inlet and a secondary purified gas outlet, and the primary purified gas inlet is communicated with the primary purified gas outlet through a primary purified gas pipeline; the washing device is used to remove acidic gases in the secondary purified gas to obtain purified tail gas. The above system can greatly improve the purification rate of cremation tail gas.

Description

Technical Field

[0001] The present invention relates to the field of tail gas purification, and in particular to a cremation tail gas purification system and a purification method. Background Art

[0002] The incineration tail gas generated in the existing cremation process includes acidic gas, nitrogen oxides, dust, dioxins and unburned harmful components, etc., which pollute the environment. In order to improve the environmental protection of the crematorium, the field mainly configures the purification equipment of some pollutants in a targeted manner. However, as the emission indicators become stricter, the flue gas emissions of the existing crematorium face the risk of not meeting the standards, which requires a comprehensive and reasonable configuration of the flue gas purification system to achieve deep purification of the tail gas and meet the emission standards.

[0003] The first existing document (CN 103157338 B) provides a full dry post-treatment system for smoke from a cremator, which uses a post-treatment device including a smoke-water isolation quenching device, a powder spraying device, a dust collector and an adsorption device to treat the smoke generated by the cremator. The device is simple in configuration, but does not treat harmful substances such as acidic gases, nitrogen oxides and dioxins, which can easily cause environmental pollution.

[0004] The second existing document (CN107327854A) provides a simple system consisting of a combustion chamber, a bag filter and an activated carbon filter tower. The system cannot remove acidic gases and nitrogen oxides present in smoke, and has high heat loss.

[0005] The third existing document (CN110180356A) provides a device and method for treating incinerator flue gas, which consists of a quenching tower, a spark interceptor, a bag filter, a heat exchanger, a low-temperature plasma reaction device and a flue gas absorption device, and can deeply purify the odor, sulfide, nitrogen oxide, dioxin and other pollutants in the flue gas. However, the tail gas of the integrated device also contains combustible gas, which will lead to the problem of excessive emission of combustible gas in the tail gas.

[0006] It can be seen that the existing cremator tail gas purification system has a poor purification effect, resulting in the problem of excessive emission of purified tail gas. Therefore, it is necessary to provide a purification system with a higher purification effect on cremator tail gas. Summary of the invention

[0007] The main purpose of the present invention is to provide a cremation exhaust gas purification system and purification method to solve the problem that the existing crematorium exhaust gas purification system has poor purification effect, resulting in excessive emissions of purified exhaust gas.

[0008] To achieve the above object, on the one hand, the present invention provides a cremation tail gas purification system, which includes: a fan, a combustion device, a quenching device, an adsorption and dust removal device, a denitrification device, and a washing device. The fan is provided with a cremation tail gas inlet and a cremation tail gas outlet; the combustion device is provided with a first feed inlet, a second feed inlet, and a combustion tail gas outlet, wherein the first feed inlet is communicated with the cremation tail gas outlet, and the second feed inlet is used for conveying fuel and combustion-supporting gas; the quenching device is provided with a refrigerant inlet, a combustion tail gas inlet, and a cooling gas outlet, and the combustion tail gas inlet is connected to the combustion tail gas outlet; the adsorption and dust removal device is provided with a cooling gas inlet and a primary purified gas outlet, and the cooling gas inlet is communicated with the cooling gas outlet, and is used for removing dioxins and heavy metal elements in the cooling gas; the denitrification device is provided with a primary purified gas inlet and a secondary purified gas outlet, and the primary purified gas inlet is communicated with the primary purified gas outlet through a primary purified gas pipeline; and the washing device is used for removing acidic gases in the secondary purified gas to obtain purified tail gas.

[0009] Further, the fan is a high-temperature fan.

[0010] Further, the combustion device includes: a primary heat exchange device, a combustion chamber, and a secondary heat exchange device. The primary heat exchange device is used for exchanging heat between the combustion tail gas and the cremation tail gas; the combustion chamber is used for burning the cremation tail gas processed by the primary heat exchange device to obtain combustion tail gas; and the secondary heat exchange device is used for exchanging heat between the combustion tail gas and the combustion-supporting gas.

[0011] Further, the adsorption and dust removal device includes: an adsorption device and a dust removal device. The adsorption device is provided with a cooling gas inlet and a dust-containing tail gas outlet; the dust removal device is provided with a dust-containing tail gas inlet and a primary purified gas outlet, the cooling gas inlet is communicated with the cooling gas outlet, and the dust-containing tail gas outlet is communicated with the dust-containing tail gas inlet.

[0012] Further, the denitrification device is an ozone oxidation denitrification device.

[0013] Further, the cremation tail gas purification system further includes a boosting device, and the boosting device is arranged on the primary purified gas pipeline.

[0014] Further, the cremation tail gas purification system further includes a flue gas heat exchange device. The flue gas heat exchange device includes a cooling zone and a heating zone. The cooling zone is used for cooling the primary purified gas discharged from the boosting device, and the heating zone is used for heating the purified tail gas processed by the washing device.

[0015] Further, the washing device is a reverse spray alkaline washing device.

[0016] Another aspect of the present application also provides a method for purifying cremation tail gas, which includes: accelerating the cremation tail gas by a blower and then burning it with fuel and combustion-supporting gas to obtain combustion tail gas; quenching the combustion tail gas and then performing adsorption and dust removal treatment to obtain primary purified gas; performing denitrification treatment on the primary purified gas to obtain secondary purified gas; and washing the secondary purified gas to obtain purified tail gas.

[0017] Further, the adsorption and dust removal step includes: adsorbing the combustion gas with an activated carbon adsorbent to remove dioxins and metal elements in the combustion gas to obtain dust-containing tail gas; and performing dust removal treatment on the dust-containing tail gas to obtain primary purified gas; preferably, the adsorbent is an activated carbon adsorbent.

[0018] Further, the temperature of the combustion process is 850-900 °C and the time is 2-3 s.

[0019] Further, the combustion process also includes heat exchange of the combustion tail gas with the combustion-supporting gas and the cremation tail gas conveyed by the blower in sequence. Preferably, the temperature of the combustion tail gas is reduced to 550 °C.

[0020] Further, the quenching step includes quenching the combustion tail gas with a mixture of water and compressed air as a refrigerant. Preferably, after the quenching step, the temperature of the combustion cold gas is 200-230 °C.

[0021] Further, between the adsorption agent and dust removal treatment step and the denitrification treatment step, the purification method further includes: pressurizing the primary purified gas.

[0022] Further, the denitrification process includes: oxidizing the primary purified gas with ozone. Preferably, the concentration of ozone is 120-180 g / m 3 .

[0023] Further, the purification process also includes: cooling the primary purified gas after pressurization treatment, and at the same time heating the purified tail gas; preferably, the temperatures of the purified tail gas and the primary purified gas are 50-140 °C.

[0024] Applying the technical solution of the present invention, the fan can create a negative pressure at the cremation tail gas inlet, which is beneficial to improving the transportation efficiency of the cremation tail gas. At the same time, it is also beneficial to inhibit the escape of harmful gases and improve the environmental protection of the purification system. In the combustion system, the cremation tail gas undergoes secondary combustion, which is beneficial to improving the combustion degree of organic matter in the cremation tail gas and reducing the content of harmful gases such as CO. In the quenching device, the combustion tail gas is quenched, which can inhibit the secondary synthesis of dioxins in the subsequent process. The quenched cooling gas is transported to the adsorption and dust removal device, where it can first adsorb dioxins and heavy metal elements in the cooling gas and then remove them from the cooling gas to obtain primary purified gas. Passing the primary purified gas through the denitrification device can remove nitrogen-containing compounds therein to obtain secondary purified gas. In the washing device, the acidic gas in the secondary purified gas is removed through washing, thereby purifying the tail gas. In summary, adopting the above purification system can greatly improve the removal rate of acidic gases and nitrogen oxides in the cremation tail gas, reduce the content of dioxins, and the dust content in the purified tail gas is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0026] Figure 1 shows a schematic structural diagram of a cremator tail gas purification system provided according to a preferred embodiment of the present invention; and

[0027] Figure 2 shows a schematic structural diagram of a combustion device provided according to a preferred embodiment of the invention.

[0028] Among them, the above-mentioned drawings include the following reference numerals:

[0029] 10, fan; 20, combustion device; 21, primary heat exchange device; 211, heat absorption side; 212, heat release side; 22, combustion chamber; 23, secondary heat exchange device; 201, first feed port; 202, second feed port; 203, combustion chamber outlet; 204, combustion tail gas outlet; 30, quenching device; 40, adsorption and dust removal device; 41, adsorption device; 42, dust removal device; 50, denitrification device; 60, washing device; 70, booster device; 80, flue gas heat exchange device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0031] As described in the background art, the existing cremator tail gas purification system has a poor purification effect, resulting in the problem that the purified tail gas emissions exceed the standard. To solve the above technical problems, the present application provides a cremation tail gas purification system, as Figure 1 shown, the cremation tail gas purification system includes: a fan 10, a combustion device 20, a quenching device 30, an adsorption and dust removal device 40, a denitration device 50, and a washing device 60. The fan 10 is provided with a cremation tail gas inlet and a cremation tail gas outlet; the combustion device 20 is provided with a first feed port 201, a second feed port 202, and a combustion tail gas outlet 204, wherein the first feed port 201 is communicated with the cremation tail gas outlet, and the second feed port 202 is used for conveying fuel gas and combustion-supporting gas; the quenching device 30 is provided with a combustion tail gas inlet and a cooling gas outlet, and the combustion tail gas inlet is connected with the combustion tail gas outlet 204; the adsorption and dust removal device 40, the adsorption and dust removal device 40 is provided with a cooling gas inlet and a primary purified gas outlet, and the cooling gas inlet is communicated with the cooling gas outlet, and is used for removing dioxins and heavy metal elements in the cooling gas; the denitration device 50 is provided with a primary purified gas inlet and a purified tail gas outlet, and the primary purified gas inlet is communicated with the primary purified gas outlet through a primary purified gas conveying pipeline; the washing device 60 is used for removing acidic gases in the secondary purified gas.

[0032] In the above-mentioned cremation tail gas purification system provided by the present application, the fan 10 can form a negative pressure at the cremation tail gas inlet, which is beneficial to improving the conveying efficiency of the cremation tail gas, and at the same time is beneficial to suppressing the escape of harmful gases and improving the environmental protection of the purification system; in the combustion system, the cremation tail gas is combusted for the second time, which is beneficial to improving the combustion degree of organic matter in the cremation tail gas and reducing the content of harmful gases such as CO; in the quenching device 30, the combustion tail gas is quenched, which can inhibit the secondary synthesis of dioxins in the subsequent process; the quenched cooling gas is transported to the adsorption and dust removal device 40, which can first adsorb dioxins and heavy metal elements in the cooling gas, and then remove them from the cooling gas to obtain primary purified gas; the primary purified gas can remove nitrogen-containing compounds therein through the denitration device 50 to obtain secondary purified gas; in the washing device 60, the acidic gases in the secondary purified gas are removed through washing, thereby purifying the tail gas. In summary, using the above-mentioned cremation tail gas purification system can greatly improve the removal rate of acidic gases and nitrogen oxides in the cremation tail gas, reduce the content of dioxins, and the soot content in the purified tail gas is low.

[0033] Preferably, the above-mentioned cremation tail gas purification system may include multiple cremators and multiple fans 10 connected to them one by one to ensure the stable and reliable operation of the cremators during each working period, and at the same time ensure the stable negative pressure of each cremator system. Preferably, the above-mentioned fan 10 is a high-temperature fan. The high-temperature fan has good high-temperature resistance, so it can ensure the operation stability of the whole system.

[0034] In a preferred embodiment, the combustion device 20 includes: a primary heat exchange device 21, a combustion chamber 22, and a secondary heat exchange device 23. The primary heat exchange device 21 is used to exchange heat between the combustion exhaust gas and the cremation exhaust gas. The combustion chamber 22 is used to burn the cremation exhaust gas processed by the primary heat exchange device 21 to obtain combustion exhaust gas. The secondary heat exchange device 23 is used to exchange heat between the above-mentioned combustion exhaust gas and the combustion-supporting gas.

[0035] The combustion process carried out at a relatively high temperature is beneficial to reducing the generation of dioxins. Therefore, in order to reduce the content of dioxins and improve the utilization rate of heat at the same time, the combustion exhaust gas with a relatively high temperature is first subjected to the first heat exchange with the cremation exhaust gas entering the combustion device 20 subsequently in the first heat exchange device. The combustion exhaust gas after the first heat exchange is then subjected to the second heat exchange with the combustion-supporting gas in the second heat exchange device. The cremation exhaust gas and the combustion-supporting gas after heat exchange enter the combustion chamber 22 for combustion to obtain combustion exhaust gas. Through the combustion device 20, on the one hand, the combustible gas in the cremation exhaust gas can be removed by combustion, which is beneficial to improving the purification degree of the finally obtained purified exhaust gas. On the other hand, the heat recycling utilization rate can be improved through heat exchange.

[0036] The above-mentioned primary heat exchange device 21 and secondary heat exchange device 23 only need to be able to achieve heat exchange, and their structures are not specifically limited. Preferably, as Figure 2 shown, the primary heat exchange device 21 includes an endothermic side 211 and an exothermic side 212, which are separated by a partition with heat conduction function. The cremation exhaust gas enters the endothermic side of the primary heat exchange device 21 through the first feed port 201. At the same time, the combustion gas in the combustion chamber 22 is discharged from the combustion chamber outlet 203, and then transported to the exothermic side of the primary heat exchange device 21. The heat of the exothermic side 212 is conducted to the endothermic side to raise the temperature of the cremation exhaust gas, and the cremation exhaust gas after the temperature rise enters the combustion chamber 22. The combustion exhaust gas after the first heat exchange is transported to the secondary heat exchange device 23. At the same time, the combustion-supporting gas enters the secondary heat exchange device 23 through the second feed port 202, and the two perform non-contact heat exchange. The combustion-supporting gas after the temperature rise is transported to the combustion chamber 22, and at the same time, the combustion gas after the second heat exchange enters the subsequent quenching device 30. By adopting the above-mentioned combustion device 20, on the one hand, the cremation exhaust gas can be burned, and on the other hand, the heat in the combustion process can be fully utilized to reduce energy loss.

[0037] The above-mentioned adsorption and dust removal device 40 can be any device with adsorption and dust removal functions in the art, and its specific structure is not limited. In a preferred embodiment, the adsorption and dust removal device 40 includes an adsorption device 41 and a dust removal device 42. The adsorption device 41 is provided with a cooling gas inlet, an adsorbent inlet, and a dust-containing exhaust gas outlet; the dust removal device 42 is provided with a dust-containing exhaust gas inlet and a primary purified gas outlet. The cooling gas inlet is communicated with the cooling gas outlet, and the dust-containing exhaust gas outlet is communicated with the dust-containing exhaust gas inlet.

[0038] In the adsorption device 41, dioxins and metal elements contained in the cooling gas discharged from the quenching device 30 can be removed through adsorption. However, since the adsorbent causes a problem of high solid content in the dust-containing tail gas discharged from the adsorption device, a dust removal device 42 is subsequently used to treat it to remove solid particles in the dust-containing tail gas and obtain primary purified gas. Preferably, the dust removal device 42 is a bag dust removal device 42. A low-pressure spray pulse bag filter is used to collect the soot in the flue gas. The dust-containing flue gas enters the box body from the air inlet of the dust removal chamber, and the purified gas enters the box body through the filter bag mouth in the filter bag and is discharged from the air outlet. To prevent the flue gas from condensing and affecting the normal operation of the bag filter, the dust remover is provided with perfect overall heat preservation and heating measures.

[0039] In the above cremation tail gas purification system, the denitration device 50 can adopt common types in the art. Preferably, it is an ozone oxidation denitration device 50. Compared with other denitration devices 50, the ozone oxidation denitration device 50 has more excellent denitration efficiency.

[0040] In a preferred embodiment, the cremation tail gas purification system further includes a pressurization device 70, and the pressurization device 70 is arranged on the primary purified gas pipeline. The pressurization device 70 can provide the power required for the operation of the above cremation tail gas purification system. By arranging the pressurization device 70 between the bag dust collection device and the ozone oxidation denitration device 50, on the one hand, it can provide the negative pressure required for the operation of the front-stage internal circulation regenerative combustion system, the flue gas quenching device 30 and the bag dust collector, and on the other hand, it can provide the operation power for the rear-stage ozone oxidation denitration device 50 and the washing device 60. Furthermore, in order to reduce the influence of the pressure fluctuation of the fan 10 caused by the large range of air volume change of the fan 10, multiple pressurization devices 70 are used in parallel in the activated tail gas purification system.

[0041] Preferably, the cremation tail gas purification system further includes a flue gas heat exchange device 80. The flue gas heat exchange device 80 includes a cooling zone and a heating zone. The cooling zone is used to cool the primary purified gas discharged from the pressurization device 70, and the heating zone is used to heat the purified tail gas treated by the washing device 60. Cooling the primary purified gas discharged from the pressurization device 70 is beneficial to reducing the corrosion of the primary purified gas to the denitration device 50 and meeting the requirements in terms of anti-corrosion. And heating the tail gas discharged from the washing device 60 to make its discharge temperature reach above the dew point can achieve deep white elimination and reduce the corrosion of the purified tail gas to the flue and chimney.

[0042] In a preferred embodiment, the washing device 60 is a reverse spray alkaline washing device 60. The nitrogen oxides in the secondary purified gas treated by the ozone oxidation denitration device 50 exist in the form of high valence states and are extremely soluble in water or alkaline solution to form nitrates or nitrites. Therefore, by using alkaline solution absorption, NO in the secondary purified gas of ozone oxidation denitration can be removed. xfor efficient removal. Its NO x removal rate can be as high as over 90%; meanwhile, the wet spraying process can deeply absorb pollutants such as sulfur dioxide, mercury, and dust.

[0043] On the other hand, the present application also provides a method for purifying cremation tail gas, which includes: accelerating the cremation tail gas by a blower and then burning it with fuel and combustion-supporting gas to obtain combustion tail gas; rapidly cooling the combustion tail gas and then performing adsorption and dust removal treatment to obtain primary purified gas; performing denitrification treatment on the primary purified gas to obtain secondary purified gas; and washing the secondary purified gas to obtain purified tail gas.

[0044] In the above purification method provided by the present application, the setting of the blower enables the cremation tail gas to be input under negative pressure conditions, which not only helps improve the transportation efficiency of the cremation tail gas and enables the entire cremation tail gas purification system to operate in a negative pressure environment, but also helps inhibit the escape of harmful gases and improve the environmental protection of the purification system; in the combustion system, the cremation tail gas undergoes secondary combustion, which helps improve the combustion degree of organic matter in the cremation tail gas and reduce the content of harmful gases such as CO; rapidly cooling the combustion tail gas helps inhibit the secondary synthesis of dioxins in the subsequent process; performing adsorption and dust removal treatment on the cooled gas after rapid cooling can first adsorb dioxins and heavy metal elements in the cooled gas and then remove them from the cooled gas to obtain primary purified gas; performing denitrification treatment on the primary purified gas can remove nitrogen-containing compounds therein to obtain secondary purified gas; and removing acidic gases in the secondary purified gas through washing to purify the tail gas. In summary, adopting the above purification method can greatly improve the removal rates of acidic gases and nitrogen oxides in the cremation tail gas, reduce the content of dioxins, and the soot content in the purified tail gas is relatively low.

[0045] In a preferred embodiment, the temperature during the combustion process is 850 - 900 °C, and the combustion time is 2 - 3 s. Conducting the combustion process at a relatively high temperature is beneficial to reducing the generation of dioxins. Therefore, in order to reduce the content of dioxins and at the same time improve the utilization rate of heat. More preferably, the combustion tail gas with a relatively high temperature is first heat-exchanged with the subsequent incoming cremation tail gas for the first time, and the combustion tail gas after the first heat exchange is heat-exchanged with the combustion-supporting gas again for the second time. The cremation tail gas and the combustion-supporting gas after heat exchange are burned to obtain combustion tail gas.

[0046] In a preferred embodiment, the adsorption and dust removal steps include: adsorbing the cooling gas with an adsorbent to remove the dioxins and metal elements contained therein, obtaining a dust-containing tail gas; and performing dust removal treatment on the dust-containing tail gas to obtain a primary purified gas. The adsorbent can contact the cooling gas discharged from the quenching step to adsorb the dioxins and metal elements contained therein. However, since the adsorbent will cause a problem of high solid content in the dust-containing tail gas discharged from the adsorption device, the subsequent dust removal device 42 is used to treat it to remove the solid particles in the dust-containing tail gas and obtain a primary purified gas. Preferably, the above-mentioned dust removal device 42 is a bag dust removal device. More preferably, a low-pressure pulse jet bag filter is used to collect the soot in the flue gas. The dust-containing flue gas enters the box body from the air inlet of the dust removal chamber, and the purified gas enters the box body through the filter bag mouth in the filter bag and is discharged from the air outlet. To avoid the influence of flue gas condensation on the normal operation of the bag filter, the bag filter is provided with perfect overall heat preservation and heating measures. Preferably, the above-mentioned adsorbent includes but is not limited to activated carbon.

[0047] In a preferred embodiment, the combustion process further includes exchanging heat between the combustion tail gas and the combustion-supporting gas and the cremation tail gas conveyed by the fan 10 in sequence. Conducting the combustion process at a relatively high temperature is beneficial to reducing the generation of dioxins. Therefore, in order to reduce the content of dioxins and improve the utilization rate of heat at the same time, the combustion tail gas with a relatively high temperature is first subjected to the first heat exchange with the cremation tail gas entering the combustion device 20 subsequently in the first heat exchange device, and the combustion tail gas after the first heat exchange is subjected to the second heat exchange with the combustion-supporting gas in the second heat exchange device. More preferably, the temperature of the combustion tail gas is reduced to 550 °C.

[0048] In a preferred embodiment, the above-mentioned quenching step includes quenching the combustion tail gas with a mixture of water and compressed air as the refrigerant. Using the mixture of water and compressed air as the refrigerant together is beneficial to increasing the contact area between the refrigerant and the combustion tail gas on the one hand, and beneficial to improving its cooling efficiency on the other hand. Preferably, after the quenching step, the temperature of the cooling gas is 200-230 °C. Quenching the combustion tail gas to the above temperature range is beneficial to inhibiting the secondary synthesis of dioxins.

[0049] In a preferred embodiment, between the adsorbent and dust removal treatment step and the denitrification treatment step, the purification method further includes: pressurizing the primary purified gas. Setting a pressurization step between the adsorbent and dust removal treatment step and the denitrification treatment step can, on the one hand, enable the previous combustion step, quenching step and dust collection step to be carried out under negative pressure, and on the other hand, provide operating power for the subsequent denitrification step and washing step, thereby reducing the influence of the wind pressure fluctuation in the fan 10 caused by the large change range of the air volume of the fan 10.

[0050] In a preferred embodiment, the denitrification process includes: oxidizing the primary purified gas with ozone. Preferably, the concentration of ozone is 120 - 180 g / m 3 . Using ozone with a high concentration (120 - 180 g / m 3 ) is beneficial to improving the removal efficiency of nitrogen oxides.

[0051] In a preferred embodiment, the purification process further includes: cooling the primary purified gas after pressurization treatment, and simultaneously heating the purified tail gas; preferably, the temperatures of the purified tail gas and the primary purified gas are 50 - 140 °C. Cooling the primary purified gas discharged after pressurization treatment is beneficial to reducing the corrosion of the primary purified gas to the denitrification device 50 and meeting the requirements in terms of anti-corrosion. And heating the tail gas discharged from the washing process to make its discharge temperature reach above the dew point can achieve deep white elimination and reduce the corrosion of the purified tail gas to the flue and chimney.

[0052] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0053] Embodiment 1

[0054] The cremation tail gas (450 °C) discharged from the underground flue outlets of multiple cremators is sent into the summary flue by the corresponding pre-stage high-temperature fans 10 respectively, and then transported to the combustion device 20 (internal circulation regenerative combustion system) for secondary combustion, and the temperature of the cremation tail gas is raised to 900 °C and stays for 5 seconds to obtain the combustion tail gas, and the above combustion tail gas is respectively heat-exchanged with the subsequent combustion-supporting gas and cremation tail gas to realize partial recycling of thermal energy.

[0055] The combustion tail gas after heat exchange is transported to the quenching device 30 for cooling, and the quenched combustion tail gas is cooled from 850 °C to 220 °C to obtain the cooling gas.

[0056] The above cooling gas is brought into full contact with the adsorbent (sufficient activated carbon) sprayed into the adsorption device (flue) and enters the subsequent dust removal device 42 (bag filter) to remove dioxins and heavy metal elements to obtain the primary purified gas. The separated solid particulate matter is bagged manually and transported out for disposal.

[0057] The primary purified gas obtained after being purified by the dust removal device 42 (bag filter) is pressurized by the pressurization device 70 and then cooled to 120 °C in the cooling zone of the flue gas heat exchange device 80. Then it is sent into the denitrification device 50 (ozone oxidation denitrification device 50) arranged in the latter stage for denitrification treatment to obtain the secondary purified gas.

[0058] The above-mentioned secondary purified gas is transported to the washing device 60 (wet washing system), where an aqueous sodium hydroxide solution is used as the spray liquid, and the washing is carried out by a countercurrent process. At the same time, a demister is installed at the top of the washing device 60 to remove the droplets in the gas stream. The purified tail gas after demisting is heated to 135 °C in the heating zone of the flue gas heat exchange device 80. After deep white elimination, it is discharged into the atmosphere through the chimney.

[0059] After treatment, the removal rate of acidic gases in the flue gas is 99%, and the removal rate of nitrogen oxides is 92%; the dust concentration in the discharged flue gas is lower than 5 mg / Nm 3 , realizing the removal of dioxins and white elimination.

[0060] Example 2

[0061] The cremation tail gas discharged from the underground flue outlets of multiple cremators at 550 °C is sent into the summary flue by the corresponding pre-stage high-temperature fans 10 respectively, and then transported to the combustion device 20 (internal circulation regenerative combustion system) for secondary combustion, and the temperature of the cremation tail gas is raised to 850 °C and stays for 3 seconds to obtain the combustion tail gas. Then, the above-mentioned combustion tail gas is heat-exchanged with the subsequent combustion-supporting gas and cremation tail gas respectively to realize partial recycling of thermal energy.

[0062] The heat-exchanged combustion tail gas is transported to the quenching device 30 for cooling. After quenching and temperature reduction, the combustion tail gas is reduced from 800 °C to 220 °C to obtain the cooling gas.

[0063] The above-mentioned cooling gas is brought into full contact with the adsorbent (sufficient activated carbon) sprayed into the adsorption device (flue), and then enters the subsequent dust removal device 42 (bag filter) to remove dioxins and heavy metal elements to obtain the primary purified gas. The separated solid particulate matter is manually bagged and transported out for disposal.

[0064] The primary purified gas obtained after purification by the dust removal device 42 (bag filter) is pressurized by the pressurization device 70 and then reduced to 120 °C in the cooling zone of the flue gas heat exchange device 80. Then it is sent to the denitrification device 50 (ozone oxidation denitrification device 50) installed in the latter section for denitrification treatment to obtain the secondary purified gas.

[0065] The above-mentioned secondary purified gas is transported to the washing device 60 (wet washing system), where an aqueous sodium hydroxide solution is used as the spray liquid, and the washing is carried out by a countercurrent process. At the same time, a demister is installed at the top of the washing device 60 to remove the droplets in the gas stream. The purified tail gas after demisting is heated to 135 °C in the heating zone of the flue gas heat exchange device 80. After deep white elimination, it is discharged into the atmosphere through the chimney.

[0066] After treatment, the removal rate of acidic gases in the cremation tail gas is 98.5%, and the removal rate of nitrogen oxides is 92%; the dust concentration in the discharged flue gas is lower than 5 mg / Nm 3 .

[0067] Example 3

[0068] The cremation tail gas (350 °C) discharged from the underground flue outlets of multiple cremators is sent into the summary flue by the corresponding pre-positioned high-temperature fans 10 respectively, and then conveyed to the combustion device 20 (internal circulation regenerative combustion system) for secondary combustion, and the temperature of the cremation tail gas is raised to 850 °C and stays for 4 seconds to obtain combustion tail gas, and the above-mentioned combustion tail gas is respectively heat-exchanged with the subsequent combustion-supporting gas and cremation tail gas to realize partial recycling of thermal energy.

[0069] The heat-exchanged combustion tail gas is conveyed to the quenching device 30 for cooling, and the temperature of the combustion tail gas after quenching and cooling drops from 800 °C to 220 °C to obtain cooling gas.

[0070] The above-mentioned cooling gas is fully contacted with the adsorbent (sufficient activated carbon) sprayed into the adsorption device (flue) and enters the subsequent dust removal device 42 (bag filter) to remove dioxins and heavy metal elements to obtain primary purified gas. The separated solid particulate matter is bagged manually and transported out for disposal.

[0071] The primary purified gas obtained after being purified by the dust removal device 42 (bag filter) is pressurized by the pressurizing device 70 and then cooled to 140 °C in the cooling zone of the flue gas heat exchange device 80. Then it is sent to the denitration device 50 (ozone oxidation denitration device) arranged in the latter section for denitration treatment to obtain secondary purified gas.

[0072] The above-mentioned secondary purified gas is conveyed to the washing device 60 (wet washing system) and sodium hydroxide aqueous solution is used as the spraying liquid, and it is washed by a countercurrent process. At the same time, a demister is arranged at the top of the washing device 60 to remove the droplets in the gas flow. The purified tail gas after demisting is heated to 135 °C in the heating zone of the flue gas heat exchange device 80, and after deep white elimination, it is discharged into the atmosphere through the chimney.

[0073] After treatment, the removal rate of acidic gases in the cremation tail gas is 97%, and the removal rate of nitrogen oxides is 90%; the dust concentration of the discharged flue gas is lower than 5 mg / Nm 3 , realizing dioxin removal and white elimination.

[0074] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0075] The blower can create a negative pressure at the cremation exhaust gas inlet, which is beneficial to improving the transportation efficiency of the cremation exhaust gas. At the same time, it is also beneficial to suppressing the escape of harmful gases and enhancing the environmental protection of the cremation exhaust gas purification system. In the combustion system, the cremation exhaust gas undergoes secondary combustion, which is beneficial to increasing the combustion degree of organic substances in the cremation exhaust gas and reducing the content of harmful gases such as CO. In the quenching device, the combustion exhaust gas is quenched, which can inhibit the secondary synthesis of dioxins in the subsequent process. The quenched cooling gas is transported to the adsorption and dust removal device, where it can first adsorb dioxins and heavy metal elements in the cooling gas and then remove them from the cooling gas to obtain a primary purified gas. Passing the primary purified gas through the denitrification device can remove nitrogen-containing compounds therein to obtain a secondary purified gas. In the washing device, the acidic gas in the secondary purified gas is removed through washing, thereby purifying the exhaust gas. In summary, adopting the above-mentioned cremation exhaust gas purification system can greatly improve the removal rates of acidic gases and nitrogen oxides in the cremation exhaust gas, reduce the content of dioxins, and the dust content in the purified exhaust gas is relatively low.

[0076] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of this application described herein can be implemented in an order other than those described herein, for example.

[0077] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A purification system for cremation tail gas, characterized in that, The purification system includes: A fan (10), which is provided with an inlet for cremation exhaust gas and an outlet for cremation exhaust gas; A combustion device (20), which is provided with a first feed inlet (201), a second feed inlet (202) and a combustion exhaust gas outlet (204), wherein the first feed inlet (201) is communicated with the outlet for cremation exhaust gas, and the second feed inlet (202) is used for conveying fuel and combustion-supporting gas; A quenching device (30), which is provided with a refrigerant inlet, a combustion exhaust gas inlet and a cooling gas outlet, and the combustion exhaust gas inlet is connected with the combustion exhaust gas outlet (204); An adsorption and dust removal device (40), which is provided with a cooling gas inlet and a primary purified gas outlet, and the cooling gas inlet is communicated with the cooling gas outlet, and is used for removing dioxins and heavy metal elements in the cooling gas; A denitration device (50), which is provided with a primary purified gas inlet and a secondary purified gas outlet, and the primary purified gas inlet is communicated with the primary purified gas outlet through a primary purified gas conveying pipeline; and A washing device (60), which is used for removing acidic gas in the secondary purified gas to obtain purified exhaust gas; The purification system further includes a boosting device (70), and the boosting device (70) is arranged on the primary purified gas conveying pipeline; The purification system further includes a flue gas heat exchange device (80), and the flue gas heat exchange device (80) includes a cooling zone and a heating zone. The cooling zone is used for cooling the primary purified gas discharged from the boosting device (70), and the heating zone is used for heating the purified exhaust gas processed by the washing device (60); The combustion device (20) includes: A primary heat exchange device (21), which is used for exchanging heat between the combustion exhaust gas and the cremation exhaust gas; A combustion chamber (22), which is used for burning the cremation exhaust gas processed by the primary heat exchange device (21) to obtain the combustion exhaust gas; and A secondary heat exchange device (23), which is used for exchanging heat between the combustion exhaust gas and the combustion-supporting gas; The fan (10) is a high-temperature fan.

2. The purification system according to claim 1, wherein The adsorption and dust removal device (40) includes: An adsorption device (41), which is provided with the cooling gas inlet and a dust-containing exhaust gas outlet; A dust removal device (42), which is provided with a dust-containing exhaust gas inlet and the primary purified gas outlet, the cooling gas inlet is communicated with the cooling gas outlet, and the dust-containing exhaust gas outlet is communicated with the dust-containing exhaust gas inlet.

3. The purification system according to claim 2, characterized in that The denitration device (50) is an ozone oxidation denitration device.

4. The purification system according to claim 2, characterized in that, The washing device (60) is a reverse spray alkaline washing device.

5. A purification method for cremation tail gas, characterized in that, Using the purification system for cremation exhaust gas according to any one of claims 1 to 4, the purification method includes: Accelerating the cremation exhaust gas by the fan and burning it with fuel and combustion-supporting gas to obtain combustion exhaust gas; Quenching the combustion exhaust gas and then performing adsorption and dust removal treatment to obtain primary purified gas; Perform denitrification treatment on the primary purified gas to obtain a secondary purified gas; and After washing the secondary purified gas, obtain a purified tail gas; Between the adsorption and dust removal treatment step and the denitrification treatment step, the purification method further includes: pressurizing the primary purified gas; The purification process further includes: cooling the primary purified gas after the pressurization treatment, and simultaneously heating the purified tail gas discharged during the washing process; The combustion process further includes exchanging heat between the combustion tail gas successively with the combustion-supporting gas and the cremation tail gas conveyed by the blower.

6. The purification method according to claim 5, characterized in that The adsorption and dust removal step includes: Using an activated carbon adsorbent to adsorb the combustion gas to remove dioxins and metal elements in the combustion gas, obtaining a dust-containing tail gas; and Performing dust removal treatment on the dust-containing tail gas to obtain the primary purified gas.

7. The purification method according to claim 5, characterized in that, The temperature of the combustion process is 850 - 900 °C, and the time is 2 - 3 s.

8. The purification method according to claim 5, characterized in that, Reduce the temperature of the combustion tail gas to 550 °C.

9. The purification method according to claim 5, characterized in that, The quenching step includes quenching the combustion tail gas with a mixture of water and compressed air as a refrigerant. After the quenching step, the temperature of the combustion cold gas is 200 - 230 °C.

10. The purification method according to claim 5, characterized in that The denitrification process includes: oxidizing the primary purified gas with ozone, and the concentration of the ozone is 120 - 180 g / m³.

11. The purification method according to claim 5, characterized in that, The temperatures of the purified tail gas and the primary purified gas are 50 - 140 °C.

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