AKD (Alkyl Ketene Dimer) vacuum dehydration equipment with tail gas treatment function

Abstract

AKD vacuum dehydration equipment with a tail gas treatment function comprises a reaction kettle, a nitrogen port is formed in the bottom of the reaction kettle, the nitrogen port is externally connected with a nitrogen supply pipeline, the top of the reaction kettle is communicated with an exhaust pipeline, a suspension separator is installed on the exhaust pipeline, an exhaust port of the suspension separator is communicated with a gas inlet chamber, and the gas inlet chamber is communicated with a gas outlet of the reaction kettle. The air inlet chamber is communicated with a water tank through an air outlet pipeline, a Venturi ejector is installed on the air outlet pipeline, the bottom of the water tank is further communicated with a water diversion pipeline communicated with the Venturi ejector, and a water diversion pump is installed on the water diversion pipeline. The top of the water tank is further communicated with a tail gas trap, a spraying pipeline is installed on the tail gas trap, one end of the spraying pipeline is arranged in the tail gas trap and provided with a spraying nozzle, and the other end of the spraying pipeline extends to the outer side of the tail gas trap and is communicated with the bottom of the water tank. According to the invention, the problem of water vapor removal in the dehydration process can be solved so as to ensure the quality of the AKD product, and the environmental protection load can be ensured not to be increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to AKD production technical field, especially a kind of AKD vacuum dehydration equipment with tail gas treatment function. BACKGROUND

[0002] Alkyl ketene dimer (AKD) is an unsaturated lactone, which can be used in papermaking / alkaline sizing agent, mainly used as copper plate base paper, copying paper, archive paper, dictionary paper and high-quality writing paper etc. The sizing pH value can reach about 8.0, which is widely used at home and abroad.

[0003] Currently, AKD synthesis mainly has two processes:

[0004] One is solvent method process, and the main raw materials are triethylamine, fatty acid chloride and toluene, wherein toluene is solvent, and due to the presence of solvent toluene in the synthesis reaction, the material flowability is good, and the viscosity is low, generally using kettle type stirring mixing reaction mode;

[0005] The other is solvent-free process, and the main raw materials are triethylamine and fatty acid chloride; wherein in the reaction later period of solvent-free process for synthesizing papermaking additive AKD, the material viscosity is large, and the material contains fine triethylamine hydrochloride solid particles, and the material viscosity can reach 130000 mPa.s when the temperature T=65℃, and after the reaction is completed, triethylamine hydrochloride solid particles in AKD product need to be dissolved in solution, so as to realize the stratification of AKD in triethylamine hydrochloride aqueous solution, and thus AKD product with higher purity is obtained, and finally AKD is dehydrated by vacuum dehydration to remove volatile impurities.

[0006] In the prior art, paper sizing agent AKD is generally synthesized by solvent-free process, but the dehydration of traditional process AKD adopts kettle type negative pressure distillation process, and acid-washed oil phase coarse AKD (containing 0.8-1% water) is directly added to the stirring kettle with jacket, the material temperature is heated to 100℃ by jacket heat exchange, and in the dehydration process of AKD product, water in AKD is gasified, the reactor sealing requirement is high, and the internal medium is not allowed to contact with external air, which causes water vapor to stay in the kettle and hydrolyze with high temperature AKD. UTILITY MODEL CONTENTS

[0007] The utility model solves the technical problems of the prior art, provides AKD vacuum dehydration equipment with tail gas treatment function, which can solve the water vapor removal problem in the dehydration process to ensure the quality of AKD product, and can ensure that the environmental load is not increased.

[0008] The technical problem to be solved by the utility model is realized through the following technical scheme. The utility model relates to an AKD vacuum dewatering equipment with tail gas treatment function, which comprises a reaction kettle for carrying out vacuum dewatering treatment on AKD, a nitrogen inlet is arranged at the bottom of the reaction kettle, the nitrogen inlet is connected with a nitrogen supply pipeline, an exhaust pipeline is communicated with the top of the reaction kettle, a suspension separator is installed on the exhaust pipeline, an air inlet chamber is communicated with the exhaust port of the suspension separator, the air inlet chamber is communicated with a water tank through an air outlet pipeline, a Venturi ejector is installed on the air outlet pipeline, a water inlet pipeline communicated with the Venturi ejector is further communicated with the bottom of the water tank, and a water inlet pump is installed on the water inlet pipeline; a tail gas catcher is further communicated with the top of the water tank, a spraying pipeline is installed on the tail gas catcher, one end of the spraying pipeline is arranged in the tail gas catcher and is provided with a spraying nozzle, the other end of the spraying pipeline extends to the outside of the tail gas catcher and is communicated with the bottom of the water tank, and a spraying pump is further installed on the spraying pipeline.

[0009] The technical problem to be solved by the utility model can be further realized through the following technical scheme. For the AKD vacuum dewatering equipment with tail gas treatment function, a jet pipeline communicated with the nitrogen inlet is further installed in the reaction kettle, and a plurality of jet nozzles are installed on the jet pipeline.

[0010] The technical problem to be solved by the utility model can be further realized through the following technical scheme. For the AKD vacuum dewatering equipment with tail gas treatment function, a nitrogen supply adjusting valve is installed on the nitrogen supply pipeline, a pressure gauge is installed on the exhaust pipeline, and the nitrogen supply adjusting valve and the pressure gauge are arranged in linkage.

[0011] The technical problem to be solved by the utility model can be further realized through the following technical scheme. For the AKD vacuum dewatering equipment with tail gas treatment function, the suspension separator and the air outlet pipeline are both communicated with the top of the air inlet chamber, and an air inlet and outlet port with a control valve is further arranged at the bottom of the air inlet chamber.

[0012] The technical problem to be solved by the utility model can be further realized through the following technical scheme. For the AKD vacuum dewatering equipment with tail gas treatment function, a water inlet port with a control valve is further arranged on the water tank.

[0013] The technical problem to be solved by the utility model can be further realized through the following technical scheme. For the AKD vacuum dewatering equipment with tail gas treatment function, a heat exchange jacket is sleeved on the outside of the suspension separator.

[0014] The technical problems to be solved by the utility model also can be further realized through following technical scheme, for above described AKD vacuum dewatering equipment with tail gas treatment function, stirring device is installed on reaction kettle, heat exchange jacket is also sleeved on the outside of reaction kettle.

[0015] Compared with prior art, the utility model carries out optimization to process characteristic, especially, nitrogen gas interface is additionally arranged on reaction kettle, so as to improve the flow rate of dewatering steam, effectively solve the problem of water vapor emission, simultaneously, in view of the improvement of flow rate, corresponding improvement is carried out to vacuum system, water vapor trapping device is increased, after introducing nitrogen gas system, the function of original environmental protection facility is maintained, and the dewatering efficiency and product quality are successfully improved, and no additional burden is brought to environment. BRIEF DESCRIPTION OF DRAWINGS

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

[0017] In order to make the purpose, technical scheme and advantage of the utility model embodiment more clear, the technical scheme in the utility model embodiment will be described clearly and completely below in conjunction with the drawings of the utility model, obviously, the described embodiment is a part of the embodiment of the utility model, rather than all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the range of protection of the utility model.

[0018] Referring to Figure 1 An AKD vacuum dewatering equipment with tail gas treatment function is designed for the vacuum dewatering treatment of AKD (alkyl ketene dimer, a sizing agent commonly used in papermaking industry), integrates tail gas treatment function, so as to ensure the environmental protection and high efficiency of production process, the equipment includes reaction kettle 1 for carrying out vacuum dewatering treatment to AKD, is used for carrying out dewatering treatment to AKD under vacuum condition, so as to improve its performance and application effect, specifically:

[0019] Nitrogen gas port is arranged at the bottom of reaction kettle 1, nitrogen gas port is connected with nitrogen gas supply pipeline 6, is used for conveying nitrogen gas to reaction kettle 1, nitrogen gas is inert gas here, can protect AKD, and also facilitates to accelerate water vapor separation, improves dewatering effect, preferably, nitrogen gas supply regulating valve is installed on nitrogen gas supply pipeline 6, can accurately control the flow of nitrogen gas, so as to meet the demand under different production conditions.

[0020] In order to uniformly inject nitrogen gas into reaction kettle 1, improve the utilization rate and protection effect of nitrogen gas, jet pipeline that communicates with nitrogen gas port is also installed in the inside of reaction kettle 1, a plurality of jet nozzles are installed on jet pipeline.

[0021] An exhaust pipeline 7 is communicated with the top of the reaction kettle 1, for discharging the water vapor and tail gas generated by the reaction kettle 1, in order to effectively separate the solid particles and liquid in it, a suspension separator 2 is installed on the exhaust pipeline 7, which can efficiently remove the impurities in the tail gas, and ensure the smooth progress of the subsequent tail gas treatment, preferably, a heat exchange jacket is sleeved outside the suspension separator 2, which can adjust the working temperature of the suspension separator 2 according to the needs, and ensure the stable operation of the equipment.

[0022] The exhaust port of the suspension separator 2 is communicated with an air inlet chamber 3, the air inlet chamber 3 is communicated with a water tank 4 through an air outlet pipeline 8, and a Venturi ejector 9 is installed on the air outlet pipeline 8, which is a device for generating negative pressure by using high-speed airflow to suck liquid or gas, here, the Venturi ejector 9 is used not only for vacuum suction of the reaction kettle 1 through the air inlet chamber 3, but also for introducing water in the water tank 4 into the air outlet pipeline 8 to mix with the tail gas, further purifying the tail gas; in order to ensure the normal work of the Venturi ejector 9, a water inlet pipeline 10 communicated with the Venturi ejector 9 is further communicated with the bottom of the water tank 4, and a water inlet pump is installed on the water inlet pipeline 10 to provide the necessary water flow power.

[0023] A tail gas catcher 5 is further communicated with the top of the water tank 4, for capturing and further treating the tail gas, a spray pipeline 11 is installed on the tail gas catcher 5, one end of the spray pipeline 11 is arranged inside the tail gas catcher 5 and is provided with a spray nozzle for spraying water mist into the tail gas to further remove harmful substances in the tail gas, the other end of the spray pipeline 11 extends to the outside of the tail gas catcher 5 and is communicated with the bottom of the water tank 4, forming a circulating water system, in order to provide the power required for spraying, a spray pump is further installed on the spray pipeline 11;

[0024] Preferably, the suspension separator 2 and the air outlet pipeline 8 are both communicated with the top of the air inlet chamber 3, and an air inlet and outlet port with a control valve is further arranged at the bottom of the air inlet chamber 3; an water inlet port with a control valve is further arranged on the water tank 4, which can supplement the water in the water tank 4 at any time.

[0025] In actual use, a pressure gauge is installed on the exhaust pipeline 7, and the nitrogen supply adjusting valve is arranged in linkage with the pressure gauge, that is, the opening size of the nitrogen supply adjusting valve is controlled according to the pressure detection of the pressure gauge, so that the reaction kettle 1 can always be in a negative pressure vacuum state.

[0026] A stirring device is installed on the reaction kettle 1 for continuously stirring the material during the reaction to improve the reaction efficiency and uniformity, and a heat exchange jacket is further sleeved outside the reaction kettle 1 for heating treatment of the reaction kettle 1 to realize the dehydration operation of AKD.

[0027] The AKD vacuum dewatering equipment with tail gas treatment function provided in the application has the specific process flow

[0028] I. Preparation stage

[0029] Ensure that the reaction kettle, exhaust pipeline, suspension separator, gas inlet chamber, water tank, Venturi ejector, tail gas trap and other equipment are intact, tightly connected and have no leakage.

[0030] Check whether the valves, pumps and other equipment of the nitrogen supply pipeline, water supply pipeline and spray pipeline are in normal working condition.

[0031] Prepare the AKD material to be dewatered and ensure that its quality meets the production requirements.

[0032] Prepare appropriate amount of nitrogen, water and spray liquid and other auxiliary materials according to production requirements.

[0033] II. Vacuum dewatering treatment stage

[0034] Turn on the heating device (i.e. heat exchange jacket) of the reaction kettle to heat the AKD material and make the water inside gradually evaporate.

[0035] Under the suction of the Venturi ejector, negative pressure will be generated in the reaction kettle to form a vacuum, which facilitates the output of water vapor.

[0036] At the same time, open the nitrogen supply regulating valve to blow nitrogen into the reaction kettle to accelerate the discharge of water vapor and tail gas.

[0037] The nitrogen blowing time is determined according to production requirements, and generally needs to ensure that a certain negative pressure is maintained in the reaction kettle.

[0038] The evaporated water vapor and tail gas enter the suspension separator through the exhaust pipeline for separation treatment along with the nitrogen.

[0039] In the suspension separator, the solid particles and liquid in the tail gas are effectively separated out, and the purified tail gas enters the gas inlet chamber.

[0040] The separated solid particles and liquid can be discharged or recycled through the corresponding discharge port.

[0041] III. Tail gas treatment stage

[0042] In the gas inlet chamber, the tail gas is mixed with the water in the water tank through the Venturi ejector.

[0043] The Venturi ejector uses high-speed airflow to generate negative pressure to introduce the water in the water tank into the exhaust pipeline, and after mixing with the tail gas, forms water mist.

[0044] The water mist fully contacts and reacts with the harmful substances in the tail gas to further purify the tail gas.

[0045] The purified tail gas enters the tail gas trap for further treatment;

[0046] In the tail gas trap, the spray pipeline sprays water mist into the tail gas, further removing harmful substances in the tail gas;

[0047] The spray liquid can be recycled to reduce water waste;

[0048] After the tail gas trap treatment, the harmful substance content of the tail gas is greatly reduced, meeting the environmental protection emission standard, and can be safely discharged through the discharge port.

[0049] Four, subsequent processing stage

[0050] After completing the dehydration treatment, the reaction kettle, exhaust pipeline, suspension separator, gas inlet chamber, water tank and other equipment need to be cleaned and disinfected;

[0051] During the cleaning process, an appropriate amount of cleaning agent and disinfectant can be used to ensure the cleanliness and hygiene of the equipment interior;

[0052] Regularly maintain and maintain the equipment, check the running state and wear condition of the equipment;

[0053] Replace or repair the severely worn parts to ensure normal operation of the equipment and prolong the service life.

Claims

1. An AKD vacuum dewatering apparatus with exhaust gas treatment function, characterized by: The application relates to a reaction kettle for vacuum dewatering AKD, which is provided with a nitrogen inlet at the bottom of the reaction kettle, a nitrogen supply pipeline is connected to the nitrogen inlet, an exhaust pipeline is connected to the top of the reaction kettle, a suspension separator is installed on the exhaust pipeline, an air inlet chamber is connected to the exhaust outlet of the suspension separator, a water tank is connected to the air inlet chamber through an air outlet pipeline, a Venturi ejector is installed on the air outlet pipeline, a water diversion pipeline connected to the Venturi ejector is further connected to the bottom of the water tank, and a water diversion pump is installed on the water diversion pipeline; a tail gas catcher is further connected to the top of the water tank, a spraying pipeline is installed on the tail gas catcher, one end of the spraying pipeline is arranged in the tail gas catcher and is provided with a spraying nozzle, the other end of the spraying pipeline extends to the outside of the tail gas catcher and is connected to the bottom of the water tank, and a spraying pump is further installed on the spraying pipeline.

2. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1, characterized in that: A jetting pipeline connected to the nitrogen inlet is further installed in the reaction kettle, and a plurality of jetting nozzles are installed on the jetting pipeline.

3. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1 or 2, characterized in that: A nitrogen supply adjusting valve is installed on the nitrogen supply pipeline, and a pressure gauge is installed on the exhaust pipeline; the nitrogen supply adjusting valve is arranged in linkage with the pressure gauge.

4. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1, characterized in that: The suspension separator and the air outlet pipeline are both connected to the top of the air inlet chamber, and an air inlet and outlet provided with a control valve is further arranged at the bottom of the air inlet chamber.

5. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1, characterized in that: A water inlet provided with a control valve is further arranged on the water tank.

6. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1, characterized in that: A heat exchange jacket is sleeved on the outside of the suspension separator.

7. The AKD vacuum dewatering apparatus with exhaust gas treatment function according to claim 1 or 6, characterized in that: A stirring device is installed on the reaction kettle, and a heat exchange jacket is further sleeved on the outside of the reaction kettle.

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