Fluidized bed reactor for silver-method formaldehyde production

Abstract

The utility model relates to a fluidized bed reactor for silver-method formaldehyde production, which comprises a fluidized bed reaction section and a steam pocket, the steam pocket is provided with a first pipeline and a second pipeline communicated with the steam pocket, the first pipeline and the second pipeline are communicated with a cooling section, and a cyclone separator communicated with the cooling section is arranged below the cooling section. The fluidized bed reaction section is communicated with the cyclone separator through a pipeline III; a pipeline IV communicated with the fluidized bed reaction section is arranged at the lower end of the fluidized bed reaction section; an ignition coil is arranged at the lower end in the fluidized bed reaction section, a supporting plate is arranged above the ignition coil, a multi-layer copper net is arranged on the upper end face of the supporting plate, a silver bed is arranged above the multi-layer copper net, a deflection baffle is arranged above the silver bed, and a dust removal baffle is arranged at the upper end of the fluidized bed reaction section above the deflection baffle. According to the utility model, the reaction temperature is reduced, the generation of byproducts is reduced, the utilization rate of raw materials is efficiently improved, the service life of equipment is prolonged, and the steam recovery pressure is improved, so that the heat recovery quality is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of chemical production equipment, and specifically relates to a fluidized bed reactor for silver method formaldehyde production. BACKGROUND

[0002] Formaldehyde is a widely used, simple production process, and abundant raw material supply of mass chemical product, is the mainstay in the downstream product of methanol, the world annual output is about 25 million tons, about 30% of methanol is used to produce formaldehyde. Formaldehyde can be directly used as disinfectant, bactericide, preservative, mainly used in organic synthesis, paint, rubber, pesticide industry, its derivative product mainly has polyoxymethylene, polyformaldehyde, phenolic resin, urea formaldehyde resin, amino resin, urotropin product and polyhydric alcohol etc.

[0003] Formaldehyde production process mainly has silver method and iron molybdenum method, and the market generally selects the silver method with lower cost, but due to the silver method formaldehyde production process, the reaction bed layer temperature is as high as 650 DEG C. The substantial increase of byproduct caused by ultra-high temperature generates a large amount of carbon dioxide and carbon monoxide, and a large amount of methanol raw material is wasted. At the same time, under high temperature working condition, the equipment requirement is further improved, and the equipment service life is greatly reduced. In the original process, the high-temperature gas of the catalyst is rapidly cooled by cold water, which causes serious thermal shock to the equipment. After about half a year of operation of the cooling section of the reactor, small cracks are generated irregularly, causing the cooling water to enter the process material through the cracks. The equipment needs to be stopped for repair irregularly, which causes delay in production, increases maintenance cost, and threatens production safety. SUMMARY

[0004] The utility model wants to solve the technical problem, aiming at the above problem, provide a kind of fluidized bed reactor for silver method formaldehyde production for reducing raw material consumption.

[0005] To solve the above technical problems, the technical scheme provided by the utility model is as follows: a fluidized bed reactor for silver method formaldehyde production, including fluidized bed reaction section and steam drum, the steam drum is equipped with pipeline one and pipeline two communicated with it, the pipeline one and pipeline two are communicated with cooling section, the lower portion of the cooling section is equipped with cyclone separator communicated with it, the fluidized bed reaction section is communicated with cyclone separator by pipeline three, the lower end of the fluidized bed reaction section is equipped with pipeline four communicated with it.

[0006] Further, the fluidized bed reaction section includes ignition coil, multilayer copper net, support plate, silver bed, baffle, dust baffle, the lower end in the fluidized bed reaction section is equipped with ignition coil, the upper portion of the ignition coil is equipped with support plate, the upper end surface of the support plate is equipped with multilayer copper net, the upper portion of the multilayer copper net is equipped with silver bed, the upper portion of the silver bed is equipped with baffle, the upper end of the fluidized bed reaction section is equipped with dust baffle above the baffle.

[0007] Further, the cooling section is uniformly provided with water cooling tubes, and the upper and lower ends of the water cooling tubes are communicated with the pipeline two and the pipeline one respectively.

[0008] Further, the multi-layer copper mesh adopts a 10-100 mesh copper mesh, and the catalytic silver particle size is replaced by a multi-grain section, and a 2-3mm single grain section is selected.

[0009] Further, the baffle and the dust removal baffle are both copper plates.

[0010] Further, the inlet of the cyclone separator is a tangent line at the upper middle part, so that a spiral cyclone is generated, and the escaped catalytic silver in the gas is effectively precipitated, and the outlet of the cyclone separator is vertically downward.

[0011] Further, the steam drum is provided with a pipeline five communicated therewith, the upper end of the cooling section is provided with a pipeline six communicated therewith, and the pipeline one is provided with a feeding pipe communicated therewith.

[0012] Further, after the four-component gas passes through the silver bed, the pressure is reduced to 5-15kpa, so that the gas can smoothly pass through the oxidizer without backflow and causing reheating accidents.

[0013] Further, the temperature of the methanol steam in the raw gas is 48-55℃, so that the fluidized bed reaction temperature is controlled to be 450-500℃.

[0014] Compared with the prior art, the utility model has the advantages that:

[0015] The reaction system with increased contact area and time reduces the reaction temperature, reduces the generation of by-products, and efficiently improves the raw material utilization rate. At the same time, the low reaction temperature greatly reduces the thermal shock damage of the cooling section to the cooling equipment, reduces the damage of the severe thermal shock to the equipment, prolongs the equipment use time, improves the recovery steam pressure, and thus improves the quality of heat recovery. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic view of the utility model.

[0017] Mark: A, fluidized bed reaction section, B, cyclone separator, C, cooling section, D, steam drum, I, ignition coil, II, support plate, III, multi-layer copper mesh, IV, silver bed, V, baffle, VI, dust removal baffle, VII, water cooling tube, 001, pipeline four, 002, pipeline three, 003, pipeline six, 004, pipeline one, 005, pipeline two, 006, pipeline five, 007, feeding pipe. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0019] It should be noted that all directional indications such as up, down, left, right, front, back, etc. in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture such as shown in the drawings, and if the specific posture changes, the directional indications also change accordingly.

[0020] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0021] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0022] The present application will be further described in conjunction with the drawings of the present application.

[0023] In conjunction with the drawings Figure 1 A fluidized bed reactor for formaldehyde production, comprising a fluidized bed reaction section A, a cyclone separator B, a cooling section C, and a steam drum D.

[0024] The lower part of the oxidizer is connected with the gas inlet four-element gas inlet pipeline, the top of the fluidized bed reactor A is connected with the top inlet of the cyclone separator B, and the gas inlet is connected with the tangent line at the top of the cyclone separator B.

[0025] The top gas outlet pipe of the cyclone separator B is connected with the bottom of the cooling section C, and the desalted water cooling section tube outlet is collected into a total pipe and sent to the downstream absorption unit.

[0026] The bottom of the steam drum D, the outlet pipe below the liquid level is communicated with the bottom of the desalted water cooling section, and the outlet pipe of the gas-liquid mixture at the top of the desalted water cooling section is communicated with the space part above the liquid level of the steam drum D.

[0027] The high-temperature gas 400-500℃ after the silver bed IV of the fluidized bed reaction section A passes through the baffle V and the cyclone separator B, and then is cooled to 200-250℃ in the cooling section C, while obtaining the steam of 140-150℃ and 0.3-0.5mpa. The process gas after the final cooling flows to the absorption section of the downstream unit through the outlet of the cooling section C.

[0028] The specific embodiments are described in detail in combination with experimental data:

[0029] The selected raw material is the quaternary gas of 48-58℃, which enters through the pipeline IV 001. The quaternary gas includes methanol steam, water vapor, air and tail gas. After being pressurized by the air blower, it passes through the silver bed IV to generate high-temperature exothermic reaction and obtain the reaction gas of 400-500℃.

[0030] The high-temperature gas passes through the multiple layers of copper baffle V, and the number of the baffle V is 3-8 layers. The gas enters the cyclone separator B in the tangential direction after being affected by the dust removal baffle VI at the top of the fluidized bed. Under the action of the spiral gas, a small amount of escaped small particles of the crystalline catalytic silver falls to the bottom of the cyclone separator B, which can be recycled during maintenance.

[0031] In order to realize the boiling state of the catalytic silver in the fluidized bed reaction section A, the pressure of the quaternary feed gas is increased to 15kpa for verification. However, excessive pressure will blow the silver catalyst to the top of the fluidized bed reaction section A, or even into the cyclone separator B. Therefore, the pressure of the quaternary feed gas is preferably 10-18kpa.

[0032] The high-temperature gas separates the escaped catalytic silver particles in the cyclone separator B, and flows to the desalted water cooling section to exchange heat with the desalted water in the water cooling column VII. The desalted water is heated to obtain the steam of 0.3-0.5mpa and 140-150℃. This effectively avoids the harsh heat shock when directly using the 650℃ process gas to exchange heat with the cold desalted water.

[0033] The obtained steam gas-liquid mixture flows to the steam drum D through the pipeline II 005 under pressure, and then the 0.3-0.5mpa steam is obtained after the gas-liquid separator, which is sent to the steam using unit through the pipeline V 006. The consumed desalted water is constantly supplemented by the feeding pipe 007.

[0034] After being cooled in the desalted water cooling section C, the obtained methanol mixed gas is 200-250℃, which is sent to the next absorption unit through the pipeline VI 003.

[0035] The fluidized bed reaction section A greatly reduces the temperature, and also reduces the generation of byproduct formic acid in the silver bed IV reaction, so that the requirement for the equipment material is not too harsh.

[0036] In summary, the introduction of the fluidized bed reaction system greatly increases the effective reaction time on the catalyst, and a relatively low temperature formaldehyde mixed gas is obtained.

[0037] The utility model discloses and its application mode are described, and this kind of description is not limited, and the shown in the drawing is only one of the embodiment of the utility model, and the actual structure is not limited to this. In summary, if the ordinary skilled person in the art is inspired, without departing from the utility model creation tenet, not creative design is similar to the structure mode and the embodiment of this technical scheme, all should belong to the protection scope of the utility model.

Claims

1. A fluidized bed reactor for silver method formaldehyde production comprising a fluidized bed reaction section and a steam drum, characterized by: The steam drum is provided with pipeline I and pipeline II which are communicated with the steam drum, the pipeline I and the pipeline II are communicated with the cooling section, the lower part of the cooling section is provided with a cyclone separator which is communicated with the cooling section, the fluidized bed reaction section is communicated with the cyclone separator through pipeline III, the lower end of the fluidized bed reaction section is provided with pipeline IV which is communicated with the fluidized bed reaction section; The fluidized bed reaction section comprises ignition coil, multi-layer copper mesh, support plate, silver bed, baffle, dust removal baffle, the lower end of the fluidized bed reaction section is provided with ignition coil, the upper part of the ignition coil is provided with support plate, the upper end of the support plate is provided with multi-layer copper mesh, the upper part of the multi-layer copper mesh is provided with silver bed, the upper part of the silver bed is provided with baffle, the upper end of the fluidized bed reaction section is provided with dust removal baffle.

2. The fluidized bed reactor for silver methanol production according to claim 1, characterized in that: The cooling section is uniformly provided with water cooling column pipe, the upper and lower ends of the water cooling column pipe are communicated with pipeline II and pipeline I respectively.

3. The fluidized bed reactor for silver methanol production according to claim 1, characterized in that: The multi-layer copper mesh adopts 10-100 mesh copper mesh, and the catalytic silver particle size replaces the multi-particle size section, and 2-3 mm single particle size section is selected.

4. The fluidized bed reactor for silver methanol production according to claim 1, characterized in that: The baffle and the dust removal baffle are both copper plates.

5. The fluidized bed reactor for silver methanol production according to claim 1, characterized in that: The inlet of the cyclone separator is tangent to the upper part, so that the spiral cyclone is generated, and the escaped catalytic silver in the gas is effectively precipitated, and the outlet of the cyclone separator is vertically downward.

6. The fluidized bed reactor for silver methanol production according to claim 1, characterized in that: The steam drum is provided with pipeline V which is communicated with the steam drum, the upper end of the cooling section is provided with pipeline VI which is communicated with the cooling section, and the pipeline I is provided with feeding pipe which is communicated with the pipeline I.

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