Dry acetylene production method and special equipment thereof

Abstract

The invention discloses a dry acetylene production method and special equipment thereof.The dry acetylene production method comprises the steps that nanoscale calcium carbide particles and crude acetylene gas are mixed according to the volume ratio of (0.37-0.86): 100 to serve as a first raw material, then water vapor serves as a second raw material, the first raw material and the second raw material are fed into an acetylene generator through two inlets for a reaction, and the first raw material and the second raw material are separated; the flow ratio of the second raw material to the first raw material is controlled to be (3.33-9.49): 1, so that the reaction amount of the calcium carbide and the water is controlled, and the controllable reaction capacity is realized; the reaction temperature is controlled within the range of 140-155 DEG C, the water content of the product is low, the problem of pipeline blockage is avoided, and the post-treatment cost is reduced; self-produced crude acetylene gas is used as circulating gas of a reaction system, so that self-sustaining circulating reaction is realized; the method disclosed by the invention has the advantages of controllable productivity and reaction degree, continuous feeding, simple process and easiness in cleaning, in addition, the equipment disclosed by the invention simplifies reaction process control, and has the advantages of relatively high safety, continuous production, automatic control and low energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of acetylene production, and more particularly to a method for producing dry acetylene. Background Art

[0002] Acetylene is a gas widely used in industry. It is usually produced by the reaction of calcium carbide and water in industry. The wet acetylene method and the dry acetylene method are used to obtain stable acetylene gas. Among them, the wet acetylene method is to add calcium carbide into water to produce acetylene. The particle size of calcium carbide is generally 30mm~50mm. The large particle size of calcium carbide will lead to incomplete reaction and extremely high water consumption. The reaction is uncontrollable, which will cause partial dissolution of acetylene in water, reducing the acetylene yield. The water content of the residual Ca(OH)2 lime slurry is also high, requiring additional equipment for filter pressing. The dry acetylene method is to crush the calcium carbide, whose particle size is generally 2mm~3mm, and then spray water in the form of mist. Due to the small particle size of calcium carbide, the reaction is more complete, and the water is added later, so the amount of water can be controlled, so the water content of the produced Ca(OH)2 is low, which reduces the treatment cost of the residue, can directly recover Ca(OH)2, and there is no need to worry about acetylene dissolving in water, so the yield is improved. Therefore, the dry acetylene method has obvious advantages in terms of sufficient raw material reaction, low water consumption, high yield, easy treatment of calcium carbide slag, and low cost.

[0003] However, in the dry acetylene production process, since the particle size of calcium carbide is generally 2mm to 3mm, large pieces of calcium carbide need to be crushed, resulting in high dust and safety issues. Alternatively, due to the poor penetrability of the mist water, excessive water is required. Moreover, due to the small particle size of calcium carbide, some of the particles are wrapped in mud, resulting in low acetylene yield. Alternatively, the water distribution in different areas of the reactor is uneven, resulting in incomplete reaction, which also leads to low acetylene yield. Alternatively, residual calcium carbide and impurities due to incomplete reaction can cause blockage in the reactor slurry pipeline and generator nozzle, seriously restricting the long-term operation of the generator or affecting production efficiency. Therefore, how to improve the complete reaction of calcium carbide in the acetylene process, prevent reactor blockage, reduce costs, and improve production efficiency are the current focus of technical personnel, and some experiments have also been conducted.

[0004] For example, Chinese patent CN114292669A discloses a high-utilization acetylene production system, which includes the following steps during acetylene production: injecting an acidic aqueous solution into a filter box, injecting concentrated sulfuric acid into a drying box, injecting a mixed solution between the cavity walls of a reactor, first grinding a calcium carbide block into powder and then using nitrogen to pass the calcium carbide powder into the reactor, the powdered calcium carbide in the reactor reacts with the atomized alkaline mixed solution to produce a mixed gas containing acetylene, which is transported to a filter box for reaction and neutralization, and then transported to a drying box for neutralization and drying, and finally the mixed gas containing nitrogen and acetylene gas is discharged, and finally the nitrogen and acetylene gas are separated to obtain pure acetylene gas. This invention improves the acetylene production by fully mixing the calcium carbide powder with the atomized solution, and ensures that the calcium carbide raw materials can be fully utilized in the water accumulation chamber; however, in this method, reaction residues are easily accumulated in the water accumulation chamber, which is difficult to clean; dust and solution are also easily brought out during gas transportation, and the subsequent processing temperature is not high, which is easy to clog and corrode the pipeline; inert gas nitrogen is used as the carrier gas to transport the calcium carbide powder, and the subsequent treatment adds a step of separating nitrogen and acetylene gas, which complicates the process.

[0005] For another example, Chinese patent CN102746086A discloses a dry acetylene co-production carbide slag cement process and device, including a carbide crushing system, a dry acetylene reaction system, and a cement production system; wherein liquid carbide is sent to a closed device, pressurized carbon dioxide is introduced to crush the liquid carbide, and the crushed carbide is sent to a dry acetylene reactor through iron removal, crushing, and iron removal processes. The reaction system adopts an automatic control system to accurately determine the ratio of calcium carbide to water, and the measured small-particle calcium carbide falls into the dry acetylene reactor and reacts with sprayed water. An opening is provided at the second section of the partition of the dry acetylene reactor to add aeolian sand or slag. During the rotation of the agitator, friction is formed with the calcium carbide particles wrapped in the carbide slag slurry, and the carbide slag is continuously removed, so that the calcium carbide can fully react with water, thereby improving the acetylene yield and preventing pipeline blockage. However, the addition of aeolian sand or slag will also hinder the reaction between calcium carbide and water to a certain extent and consume part of the water, thereby increasing water consumption.

[0006] For example, Chinese patent CN115650273A discloses a dry process for producing acetylene from calcium carbide and co-producing high-specific surface area calcium hydroxide and its preparation method. First, the raw calcium carbide is crushed at a temperature below 80°C, and after crushing, it is sieved to obtain calcium carbide particles with a particle size of less than 150μm. The calcium carbide is then fed into a reactor, and water at 60°C is added for reaction. During the reaction, the reaction is stirred and the temperature is continuously raised to 100-110°C. A surfactant is added to the water. As the reaction proceeds, the temperature rises, the water evaporates to form a powdery mixture, and the reaction generates acetylene gas and powdered calcium carbide slag. Finally, the acetylene gas is discharged from the reactor and collected, and the powdered calcium carbide slag is discharged from the bottom of the reactor into a collector. This method uses small-sized calcium carbide to react with water. The small calcium carbide particle size allows for more complete reaction contact. Dry calcium carbide slag is obtained by vaporizing the water by heating during the reaction, reducing post-processing and lowering costs. However, there are problems such as partial coverage of the calcium carbide by the product during the reaction, resulting in incomplete reaction, and excessive gasification and incomplete reaction.

[0007] For example, Chinese patent CN113214868A discloses an acetylene production process, which relates to the technical field of acetylene production equipment, and includes the process steps of raw material processing, feeding, reaction, cooling and impurity removal, drying and collection; wherein the acetylene generator includes a generator body and a spray device installed in the generator body, a reaction chamber is opened in the generator body, a stirring shaft is rotatably installed on the generator body, a material tray is axially installed on the stirring shaft, a connecting pipe is provided on the stirring shaft, and an installation component is provided between the connecting pipe and the stirring shaft, and the spray device includes a water inlet component, a sealing component and a water spray component, and each water spray component is respectively located above each material tray; the invention uses the arrangement of the installation component and the spray device to spray water evenly onto each material tray, so that the calcium carbide raw materials on each layer of the material tray are fully in contact with and react with water, thereby improving the degree of reaction between the calcium carbide raw materials and water, and thereby improving the yield of the product acetylene, but there is still the problem that the central part of the calcium carbide particles is wrapped by mud residue, the reaction is incomplete, and the pipeline is blocked.

[0008] In summary, by improving the acetylene production process, technicians have improved the problem of incomplete calcium carbide reaction to a certain extent and increased acetylene production, but there are still some problems: (1) The addition of other inert gases increases the subsequent separation step from acetylene gas, which complicates the process; (2) The secondary reaction liquid chamber for the incomplete secondary reaction of calcium carbide is set up, which is not easy to clean and increases the process; (3) The addition of other auxiliary materials to remove calcium carbide slag and improve the water spraying device will increase water consumption to a certain extent. The reaction amount of calcium carbide and water is difficult to control. A small amount of water will lead to incomplete calcium carbide reaction, and a large amount of water will lead to high humidity of calcium carbide slag, which will easily cause calcium carbide to be wrapped by calcium carbide slag, resulting in incomplete reaction and easy clogging of pipelines; (4) If the reaction is not stable enough, a special acetylene gas cabinet is needed to serve as a storage and transit. Acetylene is a flammable and explosive gas and requires sufficient space. The equipment occupies a large area. Summary of the Invention

[0009] In response to the problems existing in the above-mentioned prior art, the present invention provides a dry acetylene production method, which mainly solves the problems of incomplete calcium carbide reaction, uncontrollable water consumption, and high humidity of calcium carbide slag in the acetylene production process. It has the advantages of controllable production capacity and reaction degree, continuous feeding, simple process, and easy cleaning. In addition, the special equipment used in the dry acetylene production method of the present invention simplifies the reaction process control, has the advantages of relatively high safety, continuous production, automatic control, low energy consumption, and convenient subsequent treatment and recycling of impurities.

[0010] The present invention provides a dry acetylene production method, comprising the steps of calcium carbide crushing, feeding, reaction, impurity removal, drying and collection, wherein the feeding and reaction steps specifically include: (1) mixing a first powder and a first gas in a first mixing zone to form a first raw material, wherein the volume ratio of the first powder to the first gas is 0.37 to 0.86:100; (2) sucking the first raw material into the second mixing zone and reacting with the second raw material introduced into the second mixing zone to form a reactant, wherein the flow ratio of the second raw material to the first raw material is 3.33 to 9.49:1; (3) The reactants are further reacted in an acetylene generator to obtain crude acetylene gas and dusty calcium hydroxide, and the reaction temperature is controlled within the range of 140°C to 155°C; (4) The crude acetylene gas produced by the reaction is output from the acetylene generator to a subsequent treatment step for impurity removal to obtain acetylene gas, wherein the flow rate of the crude acetylene gas is 10 m / s to 20 m / s.

[0011] The first powder is a powdered solid raw material used to produce acetylene gas; the first gas is a gas that makes the first powder fluid and does not participate in the reaction; and the second raw material is an atomizable raw material used to produce acetylene gas.

[0012] The first powder used in the present invention is calcium carbide particles with a particle size of 50nm to 10μm.

[0013] The temperature of the first raw material is 80-100°C.

[0014] The second raw material used in the present invention is water vapor.

[0015] The water vapor is heated by 1° C. to 5° C. before entering the second mixing zone to become superheated water vapor.

[0016] The present invention adopts nanometer-scale calcium carbide particles as reaction raw materials, which multiplies the reaction surface area compared with the calcium carbide particles used in the existing dry acetylene method, so that the contact area between calcium carbide and water is larger, the water consumption is smaller, and acetylene gas and calcium hydroxide can be generated faster and more fully. In addition, because the calcium carbide particle size is too small, the requirements for calcium carbide crushing will be too high, which increases the energy consumption of the system. Particles with too large a particle size have a faster sedimentation rate, are difficult to feed, or have a slower reaction speed and a longer reaction time. Therefore, calcium carbide particles with a particle size of 50nm to 10μm are the preferred particle size range.

[0017] The present invention uses water vapor as another raw material. The water vapor reacts with the first raw material at a temperature of 80 to 100° C. to increase the initial reaction temperature, making the reaction occur faster. Before entering the second mixing zone, the water vapor is reheated in a heating jacket at 140 to 155° C. to increase its temperature by 1 to 5° C., becoming superheated water vapor. This prevents the water vapor from cooling and condensing during transportation, and also prevents clogging at the solid material inlet. In addition, because the heating jacket is arranged in the main heat release area of the reaction, the heat released by the reaction is used to heat the water vapor, thereby increasing the control effect of the system reaction heat. Moreover, the use of relatively pure water vapor as the raw material reduces various other impurities introduced by the use of circulating washing water or industrial mist water as the raw material.

[0018] Since the two raw materials used in the present invention are a gas phase substance and an extremely fine powder, both of which have good uniform dispersion, the reaction system is simplified to use only a fixed reactor, and the two key factors of temperature and flow rate can be monitored and adjusted.

[0019] The volume ratio of the first powder and the first gas is controlled to be 0.37-0.86:100, so that the small-size calcium carbide particles and the crude acetylene gas are fully and evenly mixed, while ensuring their fluidity and appropriate output; the amount of calcium carbide and water is controlled by controlling the flow ratio of the second raw material to the first raw material to be 3.33-9.49:1, and the calcium carbide is fully reacted with an appropriate amount of water vapor, thereby reducing the amount of water and calcium carbide consumption and improving the acetylene yield; the reactants after the first raw material and the second raw material are further reacted in the acetylene generator, and the temperature is controlled in the range of 140°C to 155°C to ensure a high and appropriate reaction temperature. The temperature should be adjusted accordingly. Too low a temperature will cause the crude acetylene gas to drop in temperature too quickly during the bag dust removal process, and the small amount of water vapor brought out will condense and block the pores. Too high a temperature will cause side reactions. During the reaction, the reaction time is regulated by adjusting the reaction space of the tail gas smoothing tube of the acetylene reactor by adjusting the amount of the two raw materials used, so that the water molecules react fully and very dry sodium hydroxide nanoparticles are obtained. The ferroselenium nanopowder produced by the nano-dispersed calcium carbide powder is easier to separate from the calcium hydroxide powder. The separated nano calcium hydroxide has a higher purity and can be directly sold as an industrial product, reducing the post-processing cost.

[0020] The impurity removal described in the present invention includes bag dust removal and acetylene purification, wherein the first gas is the crude acetylene gas after being output from the acetylene generator and subjected to bag dust removal in step (4); the crude acetylene gas after bag dust removal is also used as a heat carrier gas for the working gas in the acetylene generator; wherein the temperature of the heat carrier gas is 100-115°C.

[0021] The present invention uses crude acetylene gas after being output from the acetylene generator and subjected to bag dust removal as the carrier gas and heat carrier gas for calcium carbide particles. Since the reaction is an exothermic reaction, a large amount of heat will be released, causing the temperature of the reaction system to rise. Therefore, the present invention controls the outflow velocity of the crude acetylene gas in the acetylene generator to be 10m / s~20m / s and uses the crude acetylene gas after heat exchange and cooling to jointly balance and regulate the temperature of the reaction system; the crude acetylene gas takes away the reaction heat during transportation, and part of it is used to produce high-pressure steam. The crude acetylene gas after heat exchange and cooling is at 100~115℃, and most of the higher temperature crude acetylene gas enters the tail gas smoothing pipe of the acetylene generator as heat carrier gas to mix the heat-generating expansion gas and mixed powder in the reaction exothermic zone, so that the heat change of the tail gas smoothing pipe is within a safe and reasonable range, realizing a self-sustaining heat cycle, and a small amount of high-temperature gas is used as the carrier gas to transport calcium carbide powder; the self-produced crude acetylene gas is used as the carrier gas, and no additional impurities are introduced, and waste of other gases is also avoided.

[0022] The special equipment for the dry acetylene production method of the present invention includes an acetylene generator and a post-processing device, wherein the acetylene generator includes a Venturi mixer, the Venturi mixer is provided with a first raw material inlet arranged in the radial direction and a second raw material inlet arranged in the axial direction, wherein the first raw material inlet is connected to the premixing device, the premixing device is provided with a first powder inlet, a first gas inlet and a first mixing zone, the combined pipe section of the Venturi mixer is the second mixing zone, the outlet end of the mixing pipe section is connected to the pipe wall opening of a tail gas smoothing pipe, one end of the tail gas smoothing pipe is provided with a heat carrier interface, and the other end of the tail gas smoothing pipe is the product outlet, a heating jacket is provided on the periphery of the Venturi mixer and on the periphery of the connection area between the Venturi mixer and the tail gas smoothing pipe, the heating jacket is connected to the second raw material inlet, a section of the tail gas smoothing pipe close to the product outlet is a sedimentation section, and a second heat carrier inlet is provided in the sedimentation section.

[0023] The post-processing device includes a cyclone separation device, a bag dust collector, a crude acetylene blower, a steam generator, a pelletizer, a pressure swing adsorption device, and an acetylene purification device; wherein the post-processing device includes a cyclone separation device, a bag dust collector, and a crude acetylene blower connected in sequence between the product outlet of the tail gas smoothing pipe and the high-temperature gas inlet of the steam generator, the solid outlet of the cyclone separation device is connected to the pelletizer, the low-temperature gas outlet of the steam generator is connected to the purification air duct, and the purification air duct is connected to the pressure swing adsorption device and the acetylene purification device in sequence.

[0024] The heat carrier gas outlet of the steam generator is connected to the heat carrier gas interface and the first gas inlet through the heat carrier gas main pipe, the second heat carrier gas inlet is also connected to the heat carrier gas main pipe, and the steam outlet of the steam generator is connected to the heating jacket through a steam pipe.

[0025] The premixing device also adopts a Venturi mixer, with the axial inlet of the Venturi mixer as the first powder inlet, the radial inlet of the Venturi mixer as the first gas inlet, the tail gas smoothing pipe is arranged perpendicular to the axis of the Venturi mixer, and a feed control valve is provided between the premixing device and the first raw material inlet.

[0026] The high-temperature medium of the steam generator is high-temperature crude acetylene gas from the tail gas leveling pipe, and the low-temperature medium is pure water.

[0027] The cyclone separation equipment includes a primary cyclone separator and a secondary cyclone separator, and a selenium iron remover is provided in the pipeline between the two cyclone separators.

[0028] The special equipment used in the dry acetylene production method of the present invention has a superheated steam heating zone using a heating jacket arranged on the periphery of the tail gas smoothing pipe connection area, which can utilize the heat released by the reaction. The high-temperature medium of the steam generator uses high-temperature crude acetylene gas from the tail gas smoothing pipe, which recycles most of the heat released by the reaction to achieve a self-sustaining exothermic reaction; the low-temperature medium uses pure water, which generates steam as the raw material of the acetylene generator after heating. The steam is introduced from the second raw material port. The introduction structure uses a tapered tube extending into the mixing pipe section to avoid premature contact with the first raw material and does not introduce other impurities.

[0029] Since the steam addition amount can be controlled relatively accurately during the reaction, the steam content in the reaction product can be controlled to a relatively low level. A cyclone separation device can be used to perform gas-solid separation on the reaction product at the outlet of the tail gas smoothing pipe. After separation, the solid outlet of the cyclone separation device is connected to a pelletizer, and the pelletizer is used to extrude the dry calcium carbide slag particles. The acetylene gas contained in the solid product can be fully recovered, thereby reducing the waste of acetylene gas and the safety risk at the finished product slag bin. Moreover, the reaction amount of calcium carbide and steam can be controlled relatively accurately during the reaction, so that the output of crude acetylene gas produced can be controlled, and the crude acetylene gas can be recycled. The entire reaction process is smooth, and the reserves of crude acetylene gas do not reach the critical value. Therefore, the acetylene gas cabinet commonly used in the original conventional acetylene generation device can be eliminated, reducing the number of major hazardous sources in the system and improving the safety of the system.

[0030] The cyclone separation equipment consists of a primary cyclone and a secondary cyclone. A selenium-iron remover is installed in the pipeline between the two cyclones to recover selenium-iron impurities contained in the solid reaction product, enhancing separation efficiency and improving the purity of the resulting calcium hydroxide powder. Acetylene gas remaining adsorbed by the solid after cyclone separation and sedimentation is further squeezed out by a pelletizer, ensuring the safe production of nano-calcium hydroxide products. The finished products are then sent to a calcium hydroxide warehouse for storage.

[0031] The high-temperature gas from the steam generator is cooled to 100-115°C through heat exchange and then diverted. A portion of the crude acetylene gas is further cooled to 50°C and enters the pressure swing adsorption equipment through the low-temperature gas outlet. The phosphine contained in the gas is adsorbed by activated carbon and the like. Since the crude acetylene gas in the present invention has a low water content and a high phosphine content, the adsorption effect can achieve considerable recovery of phosphorus and sulfur elements, reducing environmental pollution. A portion of the crude acetylene gas enters the hot gas main pipe, and a small portion is regulated by a control valve and sent to the acetylene generator as carrier gas to enter the premixing device for powder dispersion and mixing. The majority of the crude acetylene gas enters the tail gas leveling pipe through the hot gas inlet as hot gas for regulating and controlling the reaction temperature. A portion of the second hot gas inlet is arranged at the settling section at the tail of the tail gas leveling pipe for backblowing the tail gas leveling pipe.

[0032] After the majority of the phosphine has been removed by adsorption, the gas enters the acetylene purification device. The acetylene purification device can adopt existing technology, for example, including at least one group of sodium hydroxide solution absorption towers, one group of sodium hypochlorite solution absorption towers, and one group of concentrated sulfuric acid absorption towers for purification. Acetylene gas with qualified moisture content and impurity gas content is obtained and sent to the VCM synthesis unit for use.

[0033] The present invention adopts the above-mentioned device to simplify the control of the reaction process, facilitate the realization of DCS automatic control, and facilitate production capacity regulation. It can also eliminate the acetylene gas cabinet commonly used in conventional acetylene generators, reduce the number of major hazardous sources in the system, and improve safety; reduce the steam content entrained in the product, and facilitate subsequent dust removal and purification treatment; and adopt a self-sustaining circulation method to remove the heat release of the reaction, maintain the stability of the reaction system, and steam can be generated by evaporating pure water by heat transfer from the reaction heat release, and can also produce steam as a by-product, thereby reducing the energy consumption of system operation; the internal structure of the reaction device is simple, and steam can be used for flushing and regeneration in a very short time, effectively extending the normal operating cycle of the generator, and convenient and quick maintenance; the material balance and heat balance of the acetylene generator can be adjusted by the solid discharge amount of the buffer feed bin and the diversion flow rate and partial pressure of the by-product steam, thereby improving the safety and stability of the system; the reaction of the acetylene generator produces dry and single crude acetylene gas, which facilitates the subsequent treatment and recycling of impurity elements.

[0034] The present invention uses nanometer-scale calcium carbide powder and water vapor to react, so that the contact area between calcium carbide and water is larger, the water consumption is smaller, the reaction is faster and more complete to generate acetylene gas, and the acetylene yield is improved; the crude acetylene gas generated by the reaction is used as a carrier gas for conveying calcium carbide powder, and the reaction amount of calcium carbide and water is controlled by controlling the conveying flow rate of the crude acetylene gas and water vapor, so that the raw materials and production capacity can be controlled by a simple process, and the reaction is stable and controllable and the crude acetylene gas is recycled, without using other gases and raw materials, thereby avoiding the introduction of unnecessary impurities; and a high reaction temperature and sufficient reaction time are guaranteed during the reaction, so that the calcium carbide and water molecules react fully, and very dry calcium hydroxide nanoparticles are obtained, thereby avoiding the calcium carbide slag carrying a certain amount of moisture to cause pipeline blockage, and the purity of the separated calcium hydroxide is higher, thereby reducing post-processing and maintenance costs and improving production efficiency; and the reaction is a self-sustaining cycle, which not only enables continuous production, but also fully utilizes the heat generated by the reaction, thereby reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the acetylene generator of the present invention.

[0036] Figure 2 It is a structural schematic diagram of the special equipment used in the dry acetylene production method of the present invention.

[0037] Figure 3 It is a schematic diagram of arranging a selenium iron remover between two-stage cyclone separators in the present invention.

[0038] The markings in the figure are: 1- calcium carbide powder silo, 2- buffer silo, 3- acetylene generator, 4- cyclone separation equipment, 5- bag dust collector, 6- crude acetylene gas cabinet, 7- steam generator, 8- pressure swing adsorption equipment, 9- acetylene purification device, 10- VCM synthesis unit, 11- pellet machine, 12- calcium hydroxide warehouse, 13- heat carrier gas main, 14- crude acetylene fan, 15- selenium iron remover, 16- heating jacket, 17- insulation layer, 19- purification air duct, 20- calcium carbide raw material silo, 21- grinding equipment, 31- premixing device, 32- feed control valve, 33- venturi mixer, 34- tail gas leveling pipe, 41- primary cyclone separator , 42-secondary cyclone separator, 50-solid outlet of cyclone separation equipment, 51-high-temperature gas inlet of steam generator, 52-heat carrier gas outlet of steam generator, 53-steam outlet of steam generator, 54-low-temperature gas outlet of steam generator, 55-steam pipe, 301-first mixing zone, 302-second mixing zone, 331-first raw material inlet, 332-second raw material inlet, 311-first powder inlet, 312-first gas inlet, 341-heat carrier gas inlet, 342-product outlet, 343-second heat carrier gas inlet, 344-sedimentation section, 401-first cleaning valve, 402-second cleaning valve. DETAILED DESCRIPTION

[0039] The embodiments of the present application will be described in more detail below. The present application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. Instead, these embodiments are provided for a more thorough and complete understanding of the present application. It should be understood that the embodiments of the present application are intended for exemplary purposes only and are not intended to limit the scope of protection of the present application.

[0040] As used herein, the term "including" is open-ended, meaning "including but not limited to." The term "according to" means "at least in part according to." The term "one embodiment" means "at least one embodiment," and the term "another embodiment" means "at least one additional embodiment." Definitions of other terms are provided in the following description.

[0041] The dedicated equipment for the dry acetylene production method of the present invention specifically includes a pre-processing device, an acetylene generator 3 and a post-processing device, wherein the pre-processing device is connected in the order of a calcium carbide raw material bin 20, a grinding device 21, a calcium carbide powder bin 1, and a buffer bin 2, and the buffer bin 2 is connected to the acetylene generator 3; The acetylene generator 3 includes a venturi mixer 33, which is provided with a first raw material inlet 331 arranged in the radial direction and a second raw material inlet 332 arranged in the axial direction, wherein the first raw material inlet 331 is connected to the premixing device 31, the premixing device 31 is provided with a first powder inlet 311, a first gas inlet 312 and a first mixing zone 301, a feed control valve 32 is provided between the premixing device 31 and the first raw material inlet 331, the combined pipe section of the venturi mixer 33 is the second mixing zone 302, the outlet end of the mixing pipe section is connected to the pipe wall opening of a tail gas smoothing pipe 34, and one end of the tail gas smoothing pipe 34 is connected to the wall opening of the tail gas smoothing pipe 34. A heat carrier gas interface 341 is provided, and the other end of the tail gas smoothing pipe 34 is a product outlet 342. A heating jacket 16 is provided on the periphery of the venturi mixer 33 and on the periphery of the connection area between the venturi mixer 33 and the tail gas smoothing pipe 34. The heating jacket 16 is connected to the second raw material inlet 332. An insulation layer 17 is provided on the periphery of the tail gas smoothing pipe 34 not provided with the heating jacket 16. A section of the tail gas smoothing pipe 34 close to the product outlet 342 is a settling section 344, and a second heat carrier gas inlet 343 is provided in the settling section 344; wherein the heat carrier gas interface 341, the first gas inlet 312 and the second heat carrier gas inlet 343 are all connected to the heat carrier gas main pipe 13; The post-processing device includes a cyclone separation device 4, a bag dust collector 5, a crude acetylene gas tank 6, a crude acetylene blower 14, a steam generator 7, a pelletizer 11, a pressure swing adsorption device 8, an acetylene purification device 9 and a VCM synthesis device 10; the cyclone separation device 4, the bag dust collector 5, the crude acetylene gas tank 6, the crude acetylene blower 14, and the steam generator 7 are connected in sequence, wherein the cyclone separation device 4 is connected to the product outlet 342 of the tail gas leveling pipe 34, and the solid outlet 50 of the cyclone separation device 4 is connected to the pelletizer. The crude acetylene blower 14 is connected to the high-temperature gas inlet 51 of the steam generator 7, and the low-temperature gas outlet 54 of the steam generator 7 is connected to the purification air duct 19. The purification air duct 19 is connected to the pressure swing adsorption equipment 8, the acetylene purification device 9, and the VCM synthesis device 10 in sequence; wherein the hot gas outlet 52 of the steam generator 7 is connected to the hot gas interface 341 and the first gas inlet 312 through the hot gas main pipe 13, and the steam outlet 53 of the steam generator 7 is connected to the heating jacket 16 through the steam pipe 55; The cyclone separation device 4 includes a primary cyclone separator 41 and a secondary cyclone separator 42. A selenium iron remover 15 is provided between the primary cyclone separator 41 and the secondary cyclone separator 42. The primary cyclone separator 41 is connected to the product outlet 342 of the exhaust gas leveling pipe 34. The top of the secondary cyclone separator 42 is connected to the ash-carrying fan 18. A first ash cleaning valve 401 is provided in the connecting pipe between the primary cyclone separator 41 and the selenium iron remover 15. A second ash cleaning valve 402 is provided in the connecting pipe between the secondary cyclone separator 42 and the selenium iron remover 15. The secondary cyclone separator 42 is connected to the pelletizer 11 , and the pelletizer 11 is connected to the calcium hydroxide warehouse 12 .

[0042] The dry acetylene production method of the present invention is implemented by the following technical scheme, which is as follows: (1) Solid calcium carbide particles crushed to 2-5 mm are fed into a calcium carbide raw material bin 20, and then ground into calcium carbide powder with a particle size of 50 nm to 10 μm using a grinding device 21, and then stored in a sufficiently safe calcium carbide powder raw material bin 1 for standby use. The grinding device 21 is a dedicated Raymond mill or a dedicated circulating airflow grinder; (2) A first powder and a first gas are mixed in a first mixing zone 301 to form a first raw material, wherein the volume ratio of the first powder to the first gas is 0.37 to 0.86:100; wherein the first powder is 50 nm to 10 μm calcium carbide powder, which is metered into the buffer silo 2 through the hopper under the calcium carbide powder raw material silo 1 and then enters the first mixing zone 301; the first gas is crude acetylene gas introduced from the hot gas outlet 52 of the steam generator 7 through the hot gas main pipe 13 and the first gas inlet 312, and is allowed to enter the first mixing zone 301 as a carrier gas for the calcium carbide powder. The first raw material is a mixture of the calcium carbide powder and the crude acetylene gas, wherein the temperature of the first raw material is 80 to 100° C.; (3) The first raw material is sucked into the second mixing zone 302 and mixed with the second raw material introduced into the second mixing zone 302 to form a reactant, wherein the flow ratio of the second raw material to the first raw material is 3.33 to 9.49:1; wherein the second raw material is pure water heated to steam by the steam generator 7 and then heated by the heating jacket 16 to increase the temperature of the superheated water by 1 to 5°C, and enters the second mixing zone 302 through the second raw material inlet 332. At the same time, the first raw material enters the second mixing zone 302 from the premixing device 31 through the first raw material inlet 331; (4) The reactants are further reacted in the acetylene generator 3 to obtain crude acetylene gas and dusty calcium hydroxide, and the reaction temperature is controlled within the range of 140°C to 155°C; wherein the water vapor and calcium carbide powder react vigorously in the second mixing zone 302 to release heat to generate reaction products, namely acetylene gas, water vapor, solid calcium carbide powder particles, and nano calcium hydroxide powder particles; after a short transition, the two gases and the two granular powders are subjected to the pressure at the end of the pipeline and are rushed into the tail gas smoothing pipe 34 for further reaction to obtain crude acetylene gas and dusty calcium hydroxide, and the reaction temperature in the tail gas smoothing pipe 34 is controlled within the range of 140°C to 155°C, and a sufficient residence time is maintained to allow the water vapor and calcium carbide powder to fully react; (5) The reaction product is extended and lifted to a certain height through the tail gas leveling pipe 34, and then turned downward to enter the primary cyclone separator 41. The outflow velocity of the crude acetylene gas is 10m / s to 20m / s. Before entering the primary cyclone separator 41, a thermometer is used to monitor the operation of the reaction, a pressure gauge is used to monitor the vacuum extraction of the crude acetylene gas tank 6 and the crude acetylene blower 14, and a highly sensitive moisture monitor is used to interlock the adjustment of the steam addition amount. The crude acetylene gas tank 6 is set between the bag filter 5 and the crude acetylene blower 14. In order to prevent unexpected situations during system operation, the crude acetylene gas tank 6 may not be set during stable production. (6) The primary cyclone separator 41 separates most of the post-reaction dust and mainly transports it to the secondary cyclone separator 42. In the powder descending pipe between the two, the hollow self-cooling selenium iron remover 15 and its elbow structure are used to adsorb and enrich the particles with larger particle size, larger mass and magnetic properties. The attracted part of the selenium iron and large particles are temporarily stored in the selenium iron remover 15, and are replaced regularly and then processed separately. The nano calcium hydroxide after removing impurities enters the secondary cyclone separator 42; (7) The secondary cyclone separator 42 is transferred by the powder bin feeder of the common pneumatic conveying device and is fed by the circulating air provided by the ash-carrying fan 18 as the separation power; a spray water nozzle is provided on the top of the secondary cyclone separator 42, into which mist water at room temperature is added to entrain the reactant nanoparticles into granules and agglomerates and quickly settle them to the bottom of the cyclone separator. After falling into the star-shaped discharger at the lower end, the powder agglomerates and the powder from the bag dust collector 5 enter the pelletizer 11 together; at this time, the added mist water is partially vaporized and absorbed The heat brought by the solid material is collected, and the ash-carrying air and a small amount of steam generated plus the product acetylene are extracted through the ash-carrying fan 18, and after pre-cooling treatment, they are recycled back to the powder silo feeder of the secondary cyclone separator 42 for use as circulating air. After the above-mentioned pre-cooling process, a small amount of the ash-carrying air is separated and collected into the settling section 344 of the tail gas leveling pipe 34 for recycling. The pressure and gas output of this small amount of ash-carrying air are adjusted to ensure the circulation balance; the finished products processed by the pelletizer are sent to the calcium hydroxide warehouse 12 for storage; (8) The gas in the primary cyclone separator 41 is connected to the dust removal air duct through the air outlet after primary sedimentation and purification. The temperature is measured and controlled. When it can be kept at a high temperature above 125°C, it can prevent water vapor condensation. The automatic air valve arranged here opens, allowing the dust-containing crude acetylene gas to enter the bag dust collector 5 for physical dust removal. The crude acetylene gas after dust removal enters about 500m 3 The crude acetylene gas tank 6; the bag dust collector 5 can adopt pressure difference sensing, automatic vibration and back-blowing control to avoid excessive accumulation of nano calcium hydroxide dust affecting the pressure difference at both ends of the exhaust and the filtering and dust removal effect; (9) The crude acetylene gas is extracted and transported from one end of the crude acetylene gas cabinet 6 by the crude acetylene blower 14. The high-temperature crude acetylene gas first enters the subsequent steam generator 7. Most of the crude acetylene gas with a temperature dropped to 100-115°C is returned to the tail gas leveling pipe 34 through the heat carrier gas main pipe 13. A small amount of crude acetylene gas is cooled to 50°C and then enters the pressure swing adsorption equipment 8 through the purification air duct 19 for subsequent purification treatment. The impurity gases phosphine and hydrogen sulfide in the crude acetylene gas have a high content. It is necessary to equip it with sufficient toxic gas detection probes and combustible gas detection probes on the outside, and the emergency evacuation pipe is connected to the flare. In case of abnormal conditions, the flare can be used to quickly evacuate and burn the gas to eliminate the danger. (10) The steam outlet 53 of the steam generator 7 adopts a shrinkage hole method to ensure that the pressure in a single pipe remains constant. The single pipe outlet acts as a pressure cooker cover. The lower section of all steam generators 7 is connected together to ensure that the water temperature can rise evenly to about 100°C. Its overall appearance is similar to the vertical placement of a shell-and-tube heat exchanger. When used in series, the crude acetylene gas used for purification can be cooled to 50°C before entering the purification air duct 19. A dedicated tube-sheet heat exchanger can also be used to complete the final cooling process of the crude acetylene gas. (11) The low-temperature crude acetylene gas in the purified air duct 19 obtained above enters the pressure swing adsorption device 8, where a large amount of phosphine gas is adsorbed and removed by the pressure swing adsorption effect of the modified activated carbon. After removal, the phosphine content is made equivalent to that of the existing dry acetylene process. Thereafter, the acetylene purification device 9 is used to purify the gas using alkaline solution, circulating sodium hypochlorite solution, and concentrated sulfuric acid, and the acetylene gas with very low water content and impurity gas content is obtained and used as the feed gas for the VCM synthesis device 10. The consumption of this operation is equivalent to that of other dry acetylene processes.

[0043] Table 1 shows the specific process parameters and product results of Examples 1-3. In the above Examples 1-3, it is ensured that the amount of acetylene generated is generally equal to the apparent gas emission of the sample. After partial treatment of the calcium carbide material, the actual acetylene gas collected is converted to 320 L / kg of calcium carbide. Calcium hydroxide products with a moisture content of less than 2% are obtained by sampling during the dust removal and separation process after the reactor and at the dust collection point of the dust collector. This proves that the reaction in the present invention is efficient and controllable, and the product is dry and easy to handle.

[0044] Table 1: Specific process parameters and product results of Examples 1-3.

[0045] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A dry acetylene production method, comprising the steps of calcium carbide crushing, feeding, reaction, impurity removal, drying and collecting, characterized in that: The adding and reacting steps include the following steps: (1) mixing a first powder and a first gas in a first mixing zone to form a first raw material, wherein the volume ratio of the first powder to the first gas is 0.37 to 0.86:100; (2) sucking the first raw material into the second mixing zone and reacting with the second raw material introduced into the second mixing zone to form a reactant, wherein the flow ratio of the second raw material to the first raw material is 3.33 to 9.49:1; (3) The reactants are further reacted in an acetylene generator to obtain crude acetylene gas and dusty calcium hydroxide, and the reaction temperature is controlled within the range of 140°C to 155°C; (4) The crude acetylene gas produced by the reaction is output from the acetylene generator to a subsequent treatment step for impurity removal to obtain acetylene gas, wherein the flow rate of the crude acetylene gas is 10 m / s to 20 m / s.

2. A dry acetylene production method according to claim 1, characterized in that: The first powder is calcium carbide particles with a particle size of 50nm to 10μm.

3. The dry acetylene production method according to claim 1, characterized in that: The temperature of the first raw material is 80-100°C.

4. The dry acetylene production method according to claim 1, characterized in that: The impurity removal includes bag dust removal and acetylene purification, wherein the first gas is the crude acetylene gas output from the acetylene generator in step (4) and after bag dust removal.

5. The dry acetylene production method according to claim 4, characterized in that: The crude acetylene gas after bag dust removal is also used as a heat carrier gas for the working gas in the acetylene generator.

6. The dry acetylene production method according to claim 5, characterized in that: The temperature of the heat-carrying gas is 100-115°C.

7. The dry acetylene production method according to claim 1, characterized in that: The second raw material is water vapor.

8. The dry acetylene production method according to claim 7, characterized in that: The water vapor is heated by 1° C. to 5° C. before entering the second mixing zone to become superheated water vapor.

9. A special equipment for producing acetylene by dry process according to claim 1, characterized in that: It includes an acetylene generator (3) and a post-processing device, wherein: The acetylene generator (3) includes a venturi mixer (33), the venturi mixer (33) is provided with a first raw material inlet (331) arranged in a radial direction and a second raw material inlet (332) arranged in an axial direction, wherein the first raw material inlet (331) is connected to the premixing device (31), the premixing device (31) is provided with a first powder inlet (311), a first gas inlet (312) and a first mixing zone (301), the combined pipe section of the venturi mixer (33) is the second mixing zone (302), and the outlet end of the mixing pipe section is connected to an exhaust gas smoothing pipe (34 ) is connected to the pipe wall opening of the tail gas smoothing pipe (34), one end of the tail gas smoothing pipe (34) is provided with a heat carrier gas interface (341), the other end of the tail gas smoothing pipe is a product outlet (342), a heating jacket (16) is provided on the periphery of the venturi mixer (33) and the periphery of the connection area between the venturi mixer (33) and the tail gas smoothing pipe (34), the heating jacket (16) is connected to the second raw material inlet (332), a section of the tail gas smoothing pipe (34) close to the product outlet (342) is a settling section (344), and a second heat carrier gas inlet (343) is provided in the settling section (344); The post-processing device comprises a cyclone separation device (4), a bag dust collector (5), a crude acetylene blower (14), a steam generator (7), a pelletizer (11), a pressure swing adsorption device (8), and an acetylene purification device (9); wherein the post-processing device comprises a cyclone separation device (4), a bag dust collector (5), and a crude acetylene blower (14) connected in sequence between a product outlet (342) of a tail gas leveling pipe (34) and a high-temperature gas inlet (51) of a steam generator (7); a solid outlet (50) of the cyclone separation device (4) is connected to the pelletizer (11); a low-temperature gas outlet (54) of the steam generator (7) is connected to a purification air duct (19); and the purification air duct (19) is connected in sequence to the pressure swing adsorption device (8) and the acetylene purification device (9).

10. The dedicated equipment for the dry acetylene production method according to claim 9, characterized in that: The heat carrier gas outlet (52) of the steam generator (7) is connected to the heat carrier gas interface (341) and the first gas inlet (312) through the heat carrier gas main pipe (13), and the second heat carrier gas inlet (343) is also connected to the heat carrier gas main pipe (13). The steam outlet (53) of the steam generator (7) is connected to the heating jacket (16) through the steam pipe (55).

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