High-power monorail crane low-temperature tail gas CO purification device and method

Abstract

The invention belongs to the technical field of tail gas treatment, and particularly discloses a high-power monorail crane low-temperature tail gas CO purification device and method. A catalytic oxidation method is adopted, a honeycomb ceramic substrate is uniformly coated with Cu / Ce catalyst powder through dip-coating to construct a Cu / Ce monolithic catalyst, tail gas flows into channels of the monolithic catalyst, CO is oxidized into CO2 by utilizing the temperature of the tail gas under the action of a catalyst coating, and tail gas CO purification is realized. The low-temperature tail gas CO purification device is constructed with a Cu / Ce monolithic catalyst as a purification core, the device comprises a shell and the purification core in the shell, the shell comprises a shell body, a cooling water jacket and a flow dividing cover, and the purification core comprises the monolithic catalyst, a fixing sleeve and a heat preservation layer. The device is low in CO ignition temperature and high in low-temperature activity, the cooling water jacket is wrapped on the outermost layer, the MT990 anti-explosion requirement is met, and the device is suitable for being used by an underground high-power anti-explosion monorail crane.

Description

Technical Field

[0001] The invention belongs to the technical field of tail gas treatment, and particularly relates to a low-temperature tail gas CO purification device and method for a high-power single-track hoist. Background Art

[0002] The "Coal Mine Safety Regulations" clearly require that the CO concentration in the underground air shall not exceed 24 ppm. However, the tail gas of the high-power single-track hoist contains a large amount of CO, and the tail gas emission of the single-track hoist is one of the reasons for CO overrun. The existing method for purifying the tail gas of the single-track hoist is the water washing method, which washes harmful substances in the tail gas through an exhaust gas purification water tank. However, the solubility of CO in water is only 0.02 g / L, and this method has no purification effect on CO. The high-power single-track hoist usually adopts a two-stage tail gas cooling strategy, and an additional exhaust gas cooler is added between the exhaust outlet of the explosion-proof diesel engine and the cooling and purification water tank. After the first-stage cooling, the temperature of the tail gas is reduced to 130-150 °C, and then the temperature is further reduced to 70 °C through the exhaust gas purification water tank. The ignition temperature of the tail gas purifier used in ordinary vehicles is 250 °C, and the surface temperature is higher than 150 °C during use, which does not meet the explosion-proof requirements.

[0003] Therefore, there is temporarily no device capable of purifying the tail gas CO of the high-power single-track hoist. There is an urgent need to provide a low-temperature tail gas CO purification device and method suitable for high-power single-track hoists in coal mines. Summary of the Invention

[0004] Aiming at the problem that the tail gas CO of the current high-power single-track hoist cannot be purified, the invention provides a low-temperature tail gas CO purification device and method for a high-power single-track hoist. Based on the principle of catalytic oxidation, the Cu / Ce catalyst powder is uniformly coated on the honeycomb ceramic matrix by the dip coating method to construct a Cu / Ce monolithic catalyst. When the tail gas flows through the Cu / Ce monolithic catalyst, under the action of the catalyst coating, CO is oxidized to CO2 by using the temperature of the tail gas itself, realizing the purification of tail gas CO. A low-temperature tail gas CO purification device is constructed with the Cu / Ce monolithic catalyst as the purification core. The device includes a housing and a purification core arranged inside the housing. The housing includes a shell, a cooling water jacket, and a shunt cover. The purification core includes a monolithic catalyst, a fixing sleeve, and a heat insulation layer. The fixing sleeve can fix the position of the monolithic catalyst to avoid collision damage during use. The heat insulation layer is arranged between the fixing sleeve and the shell, which can preserve the temperature of the purification core and improve the catalytic activity. The invention is applicable to the purification of low-temperature tail gas CO of high-power single-track hoists.

[0005] To achieve the above object, the following technical solutions are provided according to the present invention:

[0006] High-power single-rail hoist low-temperature tail gas CO purification device and method, which uses catalytic oxidation method to purify CO gas in the tail gas of the single-rail hoist. Relying on the Cu / Ce monolithic catalyst, a low-temperature tail gas CO purification device is constructed. The device includes a purification device housing and a purification core arranged inside the housing.

[0007] The purification device housing includes a housing body, a cooling water jacket, and a flow dividing cover.

[0008] Optimally, the housing body includes an air intake expansion section, a gas reaction section, and an exhaust contraction section. Both the air intake expansion section and the exhaust contraction section are designed as conical structures, which can reduce the gas flow resistance. The air intake flange and the outlet flange are fixedly installed at the tops of the air intake expansion section and the exhaust contraction section respectively. The gas reaction section is circular and the purification core is placed inside.

[0009] Optimally, the cooling water jacket is wrapped outside the housing body, forming a closed cooling water interlayer between it and the housing body. The cooling water interlayer is connected to the cooling water circulation system of the single-rail hoist explosion-proof diesel engine through an inlet and an outlet. The inlet and the outlet are respectively arranged at the top and the bottom of the cooling water jacket.

[0010] Optimally, the flow dividing cover is made of a perforated mesh plate and is fixed inside the air intake expansion section of the housing body, which is the inlet of the low-temperature tail gas.

[0011] Optimally, the purification core includes a monolithic catalyst, a fixing sleeve, and a heat insulation layer.

[0012] Optimally, the monolithic catalyst is formed by coating the Cu / Ce catalyst on the cordierite honeycomb ceramic by dip coating method to form a catalyst coating. The Cu / Ce catalyst is a supported catalyst, the carrier is cerium oxide, and the active component is copper species. It is prepared by hydrothermal method and impregnation method, and has the advantages of low ignition temperature, high tolerance, and strong stability. The cordierite honeycomb ceramic carrier is cylindrical and consists of many parallel small pores.

[0013] The preparation process of the monolithic catalyst is as follows: S1: Dissolve the cerium salt in deionized water to obtain a cerium salt solution, dissolve the precipitant in deionized water to obtain a precipitant solution, dropwise add the cerium salt solution to the precipitant solution and continuously stir until a uniformly mixed slurry is obtained, then transfer the slurry to a stainless steel autoclave for hydrothermal reaction. After the reaction is completed, filter, wash, dry, and calcine to obtain a cerium oxide support; S2: Dissolve the copper salt in deionized water and stir to obtain a clear solution, uniformly disperse the cerium oxide support prepared in step S1 in the mixed solution, continuously heat under stirring until all the water evaporates, and obtain a Cu / Ce catalyst after drying and calcination; S3: Grind and sieve the Cu / Ce catalyst powder prepared in step S2, mix it with deionized water, glacial acetic acid, polyvinyl alcohol, and aluminum sol in a certain proportion, and grind it into a slurry by a ball mill. Place the cordierite honeycomb ceramic substrate in the slurry and soak it for a certain time, then take out the honeycomb ceramic substrate at a constant speed, blow the excess slurry in the pores with compressed air, and finally dry and calcine the honeycomb ceramic substrate coated with the catalyst slurry to obtain the monolithic catalyst.

[0014] Optimally, the cerium salt is cerium nitrate hexahydrate, the precipitant is sodium hydroxide, and the copper salt is copper nitrate trihydrate; the concentration of the cerium salt solution is 0.4 mol / L, and the concentration of the precipitant solution is 0.01 - 6 mol / L; the hydrothermal reaction conditions are 100 - 180 °C, 10 - 24 h, the drying conditions are 80 °C, 12 h, and the calcination conditions are 400 - 500 °C, 4 - 5 h; the mass ratio of Cu to the CeO2 support in the Cu / Ce catalyst is 0.05 - 0.08:1, the Al2O3 content of the aluminum sol is 20 wt%, the mass ratio of the powder catalyst to the Al2O3 colloid is 4 - 5 wt%, the mass ratio of the Al2O3 colloid to polyvinyl alcohol is 2.46 wt%, the drying conditions of the monolithic catalyst are 80 °C, 12 h, and the calcination conditions are 200 - 300 °C.

[0015] Optimally, the fixing sleeve is wrapped outside the monolithic catalyst and is used to fix and protect the monolithic catalyst from being damaged during use. The upper and lower ends of the fixing sleeve are connected to the inner wall of the gas reaction section of the shell.

[0016] Optimally, the heat insulation layer is filled between the fixing sleeve and the gas reaction section of the shell, which can reduce the heat dissipation of the monolithic catalyst and is beneficial to improving the catalytic activity. The heat insulation material used is aerogel felt.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] Compared with the currently used water washing method, the present invention adopts a catalytic oxidation method to lower the activation energy of the CO oxidation reaction, and uses the temperature of the tail gas itself to convert the toxic CO into non-toxic CO2, more thoroughly and effectively eliminating CO gas.

[0019] Compared with the common tail gas purifiers on the market, the purification material adopted in the present invention is a Cu / Ce supported catalyst. This catalyst has a low light-off temperature and high catalytic activity. There is a strong metal-support interaction between the active substance CuO and the CeO2 support, which can promote the adsorption and activation of O2 and CO, and improve the catalytic activity and water resistance.

[0020] The low-temperature tail gas CO purification device in the present invention has a low light-off temperature, high low-temperature activity, and strong water resistance. The light-off temperature of CO is only 60 °C, and complete conversion of CO is achieved at 150 °C. Moreover, the outside of this device is wrapped with a cooling water jacket, which can reduce the surface temperature of the device and meet the explosion-proof requirements underground. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the present invention, the following will be described in detail in combination with the drawings and detailed embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and what is described is only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Among them:

[0022] Figure 1 is the drawing of the purification device;

[0023] Figure 2 is the sectional view of the purification device;

[0024] Figure 3 is the purification core of the purification device;

[0025] Figure 4 is the purification effect diagram of CO;

[0026] Reference numerals: 110 - housing, 111 - intake expansion section, 112 - gas reaction section, 113 - exhaust contraction section, 114 - inlet flange, 115 - outlet flange, 120 - cooling water jacket, 121 - water inlet, 122 - water outlet, 130 - flow dividing cover, 200 - purification core, 210 - integral catalyst, 220 - fixing sleeve, 230 - heat insulation layer. Detailed Embodiments

[0027] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific embodiments of the present invention in combination with the drawings.

[0028] The present invention provides a high-power single-track hoist low-temperature tail gas CO purification device and method, which uses catalytic oxidation to purify CO in the tail gas and constructs a low-temperature tail gas CO purification device including a housing and a purification core inside. The outermost layer of this device is wrapped with a cooling water jacket, which is connected to the cooling water circulation system of the explosion-proof diesel engine through a rubber tube, capable of reducing the surface temperature of the device and meeting the explosion-proof requirements of MT990. The purification core of this device is a Cu / Ce monolithic catalyst, which has many parallel small pores. The Cu / Ce catalyst powder is evenly coated into the pores of the honeycomb ceramic matrix by dip coating to form a catalyst coating. When the tail gas flows through the purification device, under the action of the catalyst coating, CO is oxidized to CO2, achieving the effect of tail gas purification. This device has a low CO ignition temperature, high low-temperature activity, and strong stability, and is suitable for purifying CO in the low-temperature tail gas of high-power single-track hoists.

[0029] Example 1

[0030] As shown in the attached Figures 1-4 figure, this example provides a high-power single-track hoist low-temperature tail gas CO purification device, which includes: a purification device housing and a purification core 200 arranged inside the housing.

[0031] The purification device housing includes a housing body 110, a cooling water jacket 120, and a flow distribution cover 130.

[0032] The housing body 110 includes an intake expansion section 111, a gas reaction section 112, and an exhaust contraction section 113. Both the intake expansion section 111 and the exhaust contraction section 113 are designed as conical structures, which can reduce the gas flow resistance. The gas reaction section 112 is cylindrical, and the purification core 200 is placed inside. During specific use, the intake expansion section 111 and the exhaust contraction section 113 are respectively connected to an intake flange 114 and an outlet flange 115, and this device is connected to the single-track hoist exhaust pipe through a flange.

[0033] The cooling water jacket 120 is wrapped outside the housing body 110, forming a closed cooling water sandwich layer between it and the housing body 110. The water inlet 121 and the water outlet 122 are respectively arranged at the top and bottom of the cooling water jacket. During specific use, the water inlet 121 and the water outlet 122 are connected to the cooling water circulation system of the single-track hoist explosion-proof diesel engine through rubber tubes to reduce the surface temperature of the device.

[0034] The flow distribution cover 130 is made of a punched wire mesh plate and is fixed at the tail gas inlet inside the intake expansion section 111 of the housing body. As shown in the attached Figure 2 figure, during specific use, the flow distribution cover 130 can disperse the tail gas with a single flow direction and a relatively large flow rate into a multi-flow direction and small flow rate tail gas flow, which can avoid the occurrence of vortex phenomena inside the purifier to a certain extent, make the air flow pass through the catalyst sandwich layer more evenly, and is beneficial to reducing the exhaust back pressure and improving the purification effect.

[0035] The purification core 200 includes a monolithic catalyst 210, a fixing sleeve 220, and a heat insulation layer 230. The fixing sleeve 220 is wrapped outside the monolithic catalyst and is used to fix and protect the monolithic catalyst from being damaged during use. During specific use, the upper and lower ends of the fixing sleeve are connected to the inner wall of the gas reaction section 112 of the housing.

[0036] The heat insulation layer 230 is filled between the fixing sleeve and the gas reaction section of the housing, which can reduce the heat dissipation of the monolithic catalyst, is beneficial to improving the catalytic activity, and the heat insulation material used is aerogel felt. During specific use, the aerogel felt is bundled outside the fixing sleeve with iron tie straps and then placed into the purification device housing.

[0037] The preparation method of the Cu / Ce monolithic catalyst in this embodiment is as follows:

[0038] The Cu / Ce monolithic catalyst 210 is formed with a catalyst coating by coating the Cu / Ce catalyst on cordierite honeycomb ceramics using the dip coating method. Among them, the Cu / Ce catalyst is a supported catalyst, which is prepared by the hydrothermal method and the impregnation method. The carrier is cerium oxide, and the active component is copper species, which has the advantages of low ignition temperature, high tolerance, and strong stability. The cordierite honeycomb ceramic carrier is cylindrical and consists of many parallel small pores. The preparation process of the monolithic catalyst 210 is as follows:

[0039] S1: Dissolve the cerium salt in deionized water to obtain a cerium salt solution, dissolve the precipitant in deionized water to obtain a precipitant solution, dropwise add the cerium salt solution to the precipitant solution and continuously stir until a uniformly mixed slurry is obtained, then transfer the slurry to a stainless steel autoclave for hydrothermal reaction. After the reaction is completed, filter, wash, dry, and calcine to obtain the cerium oxide carrier;

[0040] S2: Dissolve the copper salt in deionized water and stir to obtain a clear solution. Uniformly disperse the cerium oxide carrier prepared in step S1 in the mixed solution, continuously heat under stirring until all the water evaporates, and obtain the Cu / Ce catalyst after drying and calcination;

[0041] S3: Grind and sieve the Cu / Ce catalyst powder prepared in step S2, mix it with deionized water, glacial acetic acid, polyvinyl alcohol, and aluminum sol in a certain proportion, and ball mill it into a slurry with a ball mill. Immerse the cordierite honeycomb ceramic substrate in the slurry for a certain time, then take out the honeycomb ceramic substrate at a constant speed, blow the excess slurry in the pores with compressed air, and finally dry and calcine the honeycomb ceramic substrate coated with the catalyst slurry to obtain the monolithic catalyst.

[0042] In the specific preparation process, the cerium salt is cerium nitrate hexahydrate, the precipitant is sodium hydroxide, and the copper salt is copper nitrate trihydrate; the concentration of the cerium salt solution is 0.4 mol / L, and the concentration of the precipitant solution is 2 mol / L; the hydrothermal reaction conditions are 150 o °C for 24 h, and the drying conditions are 80 o °C for 12 h, and the calcination conditions are 400 - 500 o °C for 4 h; the mass ratio between Cu and the CeO₂ support in the Cu / Ce catalyst is 0.05:1, the Al₂O₃ content in the aluminum sol is 20 wt%, the mass ratio between the Cu / Ce catalyst and the Al₂O₃ colloid is 4 wt%, the mass ratio between the Al₂O₃ colloid and polyvinyl alcohol is 2.46 wt%, and the drying conditions for the monolithic catalyst are 80 o °C for 12 h, and the calcination conditions are 200 - 300 o °C.

[0043] In Example 2, the concentration of the precipitant solution is 5 mol / L, and the hydrothermal reaction conditions are 180 o °C, and the mass ratio between Cu and the CeO₂ support in the Cu / Ce catalyst is 0.08:1, the mass ratio between the Cu / Ce catalyst and the Al₂O₃ colloid is 5 wt%. The remaining steps and raw material ratios are the same as those in Example 1.

[0044] In Example 2, the concentration of the precipitant solution is 0.01 mol / L, and the hydrothermal reaction conditions are 180 o °C, and the mass ratio between Cu and the CeO₂ support in the Cu / Ce catalyst is 0.06:1, the mass ratio between the Cu / Ce catalyst and the Al₂O₃ colloid is 4.5 wt%. The remaining steps and raw material ratios are the same as those in Example 1.

[0045] Test example:

[0046] Taking the purification device of Example 1 as the object, three groups of low-temperature gases at 60 - 160 o °C are respectively introduced into it to test the purification effect of the purification device on gases with different temperatures and different water contents. The results are as Figure 4 shown. Among them, the three groups of low-temperature gases are CO gas without water, CO gas with a water content of 0.6 vol%, and CO gas with a water content of 4.2 vol%. The rate of the gas introduced into the purification device is 8000 h -1 . In the three groups of low-temperature gases, the content of CO is 10 ppm. Figure 4 In the figure, the abscissa is the temperature and the ordinate is the CO purification amount.

Claims

1. A high-power single-rail hoist low-temperature tail gas CO purification device, characterized in that, It includes a housing and a purification core (200) disposed inside the housing; The housing includes a housing body (110), a cooling water jacket (120) and a flow dividing cover (130); the cooling water jacket (120) is wrapped outside the housing body (110), forming a closed cooling water interlayer between it and the housing body (110). The cooling water interlayer is connected to the cooling water circulation system of the single-track crane explosion-proof diesel engine through a water inlet (121) and a water outlet (122). The water inlet (121) and the water outlet (122) are respectively arranged at the top and bottom of the cooling water jacket (120); the flow dividing cover (130) is disposed inside the housing; The purification core (200) includes a monolithic catalyst (210), a fixing sleeve (220) and a heat insulation layer (230); the fixing sleeve (220) is wrapped outside the monolithic catalyst (210), and the heat insulation layer (230) is wrapped outside the fixing sleeve (220); the upper and lower ends of the fixing sleeve (220) are connected to the inner wall of the housing body (110); The low-temperature tail gas sequentially passes through the flow dividing cover (130) and the monolithic catalyst (210).

2. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 1, wherein Along the flow direction of the low-temperature gas, the housing body (110) includes an intake expansion section (111), a gas reaction section (112) and an exhaust contraction section (113) connected in sequence. The purification core (200) is disposed in the gas reaction section (112), and the flow dividing cover (130) is located in the intake expansion section (111).

3. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 2, characterized in that, Both the intake expansion section (111) and the exhaust contraction section (113) are conical structures, the gas reaction section (112) is cylindrical, the large-diameter end of the intake expansion section (111) is fixedly connected to one end of the gas reaction section (112), and the large-diameter end of the exhaust contraction section (113) is fixedly connected to the other end of the gas reaction section (112); intake flanges (114) and outlet flanges (115) are respectively fixedly installed at the small-diameter ends of the intake expansion section (111) and the exhaust contraction section (113).

4. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 1, characterized in that, The monolithic catalyst (210) includes cordierite honeycomb ceramics and a Cu / Ce catalyst coating loaded on the cordierite honeycomb ceramics.

5. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 1, characterized in that, The cordierite honeycomb ceramics are cylindrical, and several parallel channels are arranged inside them.

6. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 1, characterized in that, The preparation method of the monolithic catalyst (210) includes the following steps: S1: Dissolve a cerium salt in deionized water to obtain a cerium salt solution, dissolve a precipitant in deionized water to obtain a precipitant solution, dropwise add the cerium salt solution to the precipitant solution, and continuously stir until a uniformly mixed slurry is obtained. Then transfer the slurry to a stainless steel reaction kettle for hydrothermal reaction. After the reaction is completed, filter, wash, dry and calcine to obtain a cerium oxide support; S2: Dissolve a copper salt in deionized water and stir to obtain a copper salt solution. Uniformly disperse the cerium oxide support prepared in step S1 in the copper salt solution, continuously heat under stirring until all the water evaporates, and obtain a Cu / Ce catalyst after drying and calcining; S3: Grind and sieve the Cu / Ce catalyst prepared in step S2, then mix it with deionized water, glacial acetic acid, polyvinyl alcohol and aluminum sol, and make it into a slurry by ball milling in a ball mill. Place the cordierite honeycomb ceramic in the slurry for soaking, then take out the cordierite honeycomb ceramic, purge to remove the slurry in the pores, dry and calcine to obtain the monolithic catalyst (210).

7. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 6, characterized in that, In the step S1, the cerium salt is cerium nitrate hexahydrate, the precipitant is sodium hydroxide, and the copper salt is copper nitrate trihydrate; the concentration of the cerium salt solution is 0.4 mol / L, and the concentration of the precipitant solution is 0.01 - 6 mol / L; the hydrothermal reaction conditions are 100 - 180 o °C, 10 - 24 h, and the drying conditions are 80 o °C, 12 h, and the calcination conditions are 400 - 500 o °C, 4 - 5 h.

8. The high-power single-rail hoist low-temperature tail gas CO purification device according to claim 6, characterized in that In the step S2, the mass ratio between Cu and the CeO2 support in the Cu / Ce catalyst is 0.05 - 0.08:

1.

9. The high-power single-track hoist low-temperature tail gas CO purification device according to claim 6, characterized in that In the step S3, the Al2O3 content of the aluminum sol is 20 wt%, the mass ratio of the Cu / Ce catalyst to the Al2O3 colloid is 4 - 5 wt%, and the mass ratio of the Al2O3 colloid to polyvinyl alcohol is 2.46 wt%; the drying conditions of the monolithic catalyst (210) are 80 o °C for 12 h, and the calcination conditions are 200 - 300 o °C.

10. A purification method for the high-power single-rail hoist low-temperature tail gas CO purification device according to any one of claims 1-9, characterized in that, The low-temperature tail gas containing CO is passed through the monolithic catalyst (210) of the purification core (200), and under the action of the monolithic catalyst (210), the CO in the low-temperature tail gas is oxidized to CO2.

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