Device for preventing self-polymerization blockage of trioxymethylene concentration tower acid discharge pipeline
By canceling the shielded pressurized pump and pipeline elbows, and using a general conveying pump and inclined pipeline design, the problem of high concentration of formaldehyde self-aggregation and blockage of acid discharge pipelines at the bottom of the paraformaldehyde concentration tower is solved, achieving stable working conditions and guaranteeing personnel health.
Patent Information
- Application Number
- CN202421807389.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-29
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-07-29
AI Technical Summary
The acid discharge pipeline at the bottom of the paraformaldehyde concentration tower is prone to blockage due to the high concentration of formaldehyde self-aggregation, resulting in unstable system operation, increasing the risk of formic acid accumulation and personnel clearance.
A device for preventing self-aggregation and blocking of acid discharge pipelines in the triformaldehyde concentration tower was designed. By canceling the shielding pressurization pump and pipeline elbow, a general delivery pump was used to transport formaldehyde to the formaldehyde recovery tank at normal pressure, and then transporting it to the formaldehyde recovery tower. The discharge acid discharge pipeline and recovery pipeline were used to set up in an inclined shape to reduce the fluid residence time and avoid the accumulation of formaldehyde self-aggregation and formic acid.
It effectively avoids the accumulation of formaldehyde self-polymerization and formic acid, ensures the stable operation of the working conditions, reduces the health risks of personnel, and reduces the possibility of environmental pollution.
Smart Images
Figure CN222816820U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of devices for preventing formaldehyde self-polymerization, in particular to a device for preventing self-polymerization and clogging of an acid discharge pipeline of a trioxymethylene concentration tower. Background Art
[0002] Formaldehyde is toxic, harmful and highly polluting. Contact with formaldehyde will cause symptoms such as runny nose, swollen eyes, nausea, dizziness, and difficulty breathing. Formaldehyde is prone to crystallization and self-polymerization under low temperature, high concentration, slow flow rate and long residence time. Crystallized formaldehyde will cause pipeline blockage and affect the normal operation of the working conditions. In addition, formaldehyde has a strong odor and high degree of crystallization, making it difficult to clear and handle, affecting the long-term stable operation of the formaldehyde concentration device and the physical and mental health of personnel.
[0003] The formaldehyde preparation reactor generates 50% formaldehyde through oxidation and dehydrogenation reactions. In order to increase the formaldehyde yield, the 50% formaldehyde is concentrated to about 70% after vacuum distillation, and then mixed with the formaldehyde (65% to 68%) that has not participated in the reaction in the trioxymethylene concentration tower. Then, in the trioxymethylene reactor, under the action of a catalyst (concentrated sulfuric acid), trioxymethylene (15% to 17%) is reacted. After concentration, about 45% to 50% trioxymethylene is obtained at the top of the tower, and the formaldehyde concentration at the bottom of the tower is 65% to 68%. 90% of the formaldehyde at the bottom of the tower is sent to the trioxymethylene reactor to continue to participate in the reaction, and 10% of the formaldehyde at the bottom of the tower is sent to the formaldehyde recovery tower.
[0004] The original design was to pump the unreacted formaldehyde in the trioxymethylene reactor and the formic acid accumulated in the system through the bottom discharge pump of the trioxymethylene concentration tower, and then use it as a shielding pressure pump to pressurize the feed medium and send it to the formaldehyde recovery tower.
[0005] The following problems may occur when transporting high concentrations of formaldehyde (65% to 68%):
[0006] 1) The flow rate of the acid discharge pipeline at the bottom of the trioxymethylene concentration tower is small (0.8m 3 / h to 1.2m 3 / h), high formaldehyde concentration (65% to 68%), pipeline distance is more than 150 meters, and there are elbows. The formaldehyde recovery tower has a high reserve pressure of 0.55MPa (G), which makes the discharge and acid discharge pipeline very prone to blockage and self-polymerization.
[0007] 2) The shielding booster pump is in a state of pressure holding due to long-term blockage and self-agglomeration, causing the shielding booster pump to fail to work and cause damage to the shielding booster pump.
[0008] 3) After the acid discharge pipeline at the bottom of the trioxymethylene concentration tower is blocked, the formic acid produced in the system cannot be removed in time, causing the formic acid to accumulate in the system. The accumulated formic acid enters the post-system. In order to ensure the pH value of the bottom of the extraction tower of the post-system, the alkali solution consumption and wastewater treatment volume are increased.
[0009] 4) When high-concentration formaldehyde self-polymerization crystallization blocks the system, operators must promptly clear and handle the system. Since formaldehyde is highly toxic and difficult to handle after crystallization, it affects the physical and mental health of operators and pollutes the environment. Summary of the invention
[0010] The utility model provides a device for preventing the self-polymerization and clogging of the acid discharge pipeline of a tripolyformaldehyde concentration tower, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem that the acid discharge pipeline at the bottom of the existing tripolyformaldehyde concentration tower is easily blocked by self-polymerization of high-concentration formaldehyde.
[0011] The technical scheme of the utility model is achieved through the following measures: a device for preventing the self-aggregation and clogging of the acid discharge pipeline of a tripolyformaldehyde concentration tower, comprising a tripolyformaldehyde concentration tower, a formaldehyde recovery tank and a formaldehyde recovery tower, a discharge acid discharge pipeline is fixedly connected between the discharge port at the bottom of the tripolyformaldehyde concentration tower and the inlet of the formaldehyde recovery tank, a discharge pump 1 is connected in series on the discharge acid discharge pipeline, a recovery pipeline is fixedly connected between the outlet of the formaldehyde recovery tank and the formaldehyde recovery tower, a discharge pump 2 is connected in series on the recovery pipeline, and a low-concentration formaldehyde pipeline is fixedly connected to the recovery pipeline on the inlet side of the discharge pump 2; along the conveying direction of the fluid from left to right, the discharge acid discharge pipeline and the recovery pipeline are both inclined to the upper left and lower right.
[0012] The following are further optimizations and / or improvements to the above utility model technical solution:
[0013] The outsides of the above-mentioned discharging and acid discharging pipelines and recovery pipelines can be wrapped with heating pipelines.
[0014] The above-mentioned heating pipeline can adopt copper pipe.
[0015] The inclination angle of the above-mentioned discharging acid discharge pipeline and recovery pipeline can be 5 degrees to 10 degrees.
[0016] The above-mentioned discharging and acid discharge pipeline and recovery pipeline can be respectively connected in series with valves.
[0017] A formaldehyde circulation pipeline can be fixedly connected to a discharge and acid discharge pipeline on an inlet side of the discharge pump.
[0018] A valve may be connected in series to the formaldehyde circulation pipeline.
[0019] Compared with the existing recovery method, this device eliminates the shielded pressure pump and the elbows on the pipeline when recovering 10% formaldehyde discharged from the bottom of the trioxyformaldehyde concentration tower. It only uses a universal delivery pump (i.e., discharge pump 1 and discharge pump 2) instead of a shielded pressure pump. It first transports the formaldehyde to a normal pressure formaldehyde recovery tank and then to a formaldehyde recovery tower. At the same time, the inclined setting of the discharge acid discharge pipeline and the recovery pipeline facilitates the flow of the fluid to the right, thereby reducing the residence time of formaldehyde and formic acid in the pipeline (discharge acid discharge pipeline, recovery pipeline), further avoiding self-aggregation of formaldehyde in the pipeline, and further preventing the accumulation of formic acid in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Attached Figure 1 It is a schematic diagram of the process flow of the utility model.
[0021] The codes in the attached drawings are: 1 is a trioxyformaldehyde concentration tower, 2 is a formaldehyde recovery tank, 3 is a formaldehyde recovery tower, 4 is a discharge acid discharge pipeline, 5 is a discharge pump 1, 6 is a recovery pipeline, 7 is a discharge pump 2, 8 is a low-concentration formaldehyde pipeline, 9 is a valve, and 10 is a formaldehyde circulation pipeline. DETAILED DESCRIPTION
[0022] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical solution of the present invention and actual conditions.
[0023] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached manual. Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.
[0024] The present invention is further described below in conjunction with the embodiments and drawings:
[0025] Embodiment 1: As attached Figure 1 As shown, the device for preventing self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower comprises a trioxymethylene concentration tower 1, a formaldehyde recovery tank 2 and a formaldehyde recovery tower 3. A discharge acid discharge pipeline 4 is fixedly connected between the bottom discharge port of the trioxymethylene concentration tower 1 and the inlet of the formaldehyde recovery tank 2, a discharge pump 1 5 is connected in series to the discharge acid discharge pipeline 4, a recovery pipeline 6 is fixedly connected between the outlet of the formaldehyde recovery tank 2 and the formaldehyde recovery tower 3, a discharge pump 2 7 is connected in series to the recovery pipeline 6, and a low-concentration formaldehyde pipeline 8 is fixedly connected to the recovery pipeline 6 on the inlet side of the discharge pump 2 7; along the conveying direction of the fluid from left to right, the discharge acid discharge pipeline 4 and the recovery pipeline 6 are both inclined to the upper left and lower right.
[0026] The formaldehyde (concentration of 65% to 68%) discharged from the bottom of the trioxymethylene concentration tower 1, 10% of the discharged formaldehyde is transported to the formaldehyde recovery tank 2 through the discharge pump 1 5, the formaldehyde with a concentration of 15% is input into the recovery pipeline 6 through the low-concentration formaldehyde pipeline 8, and the formaldehyde with a concentration of 65% to 68% and the formaldehyde with a concentration of 15% are mixed in the recovery pipeline 6 and transported to the formaldehyde recovery tower 3 through the discharge pump 2 7.
[0027] During the process of recovering the formaldehyde discharged from the bottom of the tripolyformaldehyde concentration tower 1 to the formaldehyde recovery tower 3, the formic acid in the system is recovered to the formaldehyde recovery tower 3 together with the formaldehyde. The formaldehyde is recovered to the formaldehyde recovery tower 3 in time to avoid formaldehyde self-polymerization and blockage of the discharge acid discharge pipeline 4 and the recovery pipeline 6, and to avoid the accumulation of formic acid in the discharge acid discharge pipeline 4 and the recovery pipeline 6.
[0028] Compared with the existing recovery method, when the device recovers 10% formaldehyde discharged from the bottom of the trioxyformaldehyde concentration tower 1, the shielded pressure pump and the elbow on the pipeline are cancelled, and only a universal delivery pump (i.e., discharge pump 1 5, discharge pump 2 7) is used to first deliver the 10% formaldehyde to the normal pressure formaldehyde recovery tank 2, and then to the formaldehyde recovery tower 3. At the same time, with the help of the inclined setting of the discharge acid discharge pipeline 4 and the recovery pipeline 6, the fluid flows to the right, reducing the residence time of formaldehyde and formic acid in the pipeline (discharge acid discharge pipeline 4, recovery pipeline 6), further avoiding self-aggregation of formaldehyde in the pipeline, and further preventing the accumulation of formic acid in the pipeline.
[0029] This device effectively avoids formaldehyde self-polymerization and formic acid accumulation, ensuring safe, stable and long-term optimal operation, while eliminating health hazards caused by clearing blocked pipelines.
[0030] According to actual needs, the above-mentioned device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower can be further optimized and / or improved:
[0031] Embodiment 2: As an optimization of the above embodiment, as required, the outer sides of the discharging and acid discharge pipeline 4 and the recovery pipeline 6 are both wrapped with a heating pipeline.
[0032] The heating pipeline uses steam as the heating medium to ensure the temperature of the discharge and acid discharge pipeline 4 and the recovery pipeline 6.
[0033] Embodiment 3: As an optimization of the above embodiment, the heating pipeline adopts a copper pipe as required.
[0034] Embodiment 4: As an optimization of the above embodiment, according to the needs, the inclination angles of the discharging acid discharge pipeline 4 and the recovery pipeline 6 are 5 to 10 degrees.
[0035] When the angle between the discharging acid discharge pipeline 4 and the recovery pipeline 6 and the horizontal plane is 5 to 10 degrees, the blockage points of formaldehyde self-polymerization can be reduced.
[0036] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, valves 9 are respectively connected in series to the discharging and acid discharge pipeline 4 and the recovery pipeline 6.
[0037] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the discharge acid discharge pipeline 4 on the inlet side of the discharge pump 5 is fixedly connected to a formaldehyde circulation pipeline 10.
[0038] The formaldehyde (concentration of 65% to 68%) discharged from the bottom of the trioxymethylene concentration tower 1 and the other 90% of the formaldehyde are returned to the trioxymethylene reactor through the formaldehyde circulation pipeline 10 to continue to participate in the reaction.
[0039] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a valve 9 is connected in series to the formaldehyde circulation pipeline 10 .
[0040] The above technical features constitute the best implementation example of the present utility model, which has strong adaptability and best implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.
Claims
1. A device for preventing the self-polymerization and clogging of the acid discharge pipeline of a trioxymethylene concentration tower, characterized in that It includes a trioxymethylene concentration tower, a formaldehyde recovery tank and a formaldehyde recovery tower. A discharge acid discharge pipeline is fixedly connected between the bottom discharge port of the trioxymethylene concentration tower and the inlet of the formaldehyde recovery tank. A discharge pump 1 is connected in series to the discharge acid discharge pipeline. A recovery pipeline is fixedly connected between the outlet of the formaldehyde recovery tank and the formaldehyde recovery tower. A discharge pump 2 is connected in series to the recovery pipeline. A low-concentration formaldehyde pipeline is fixedly connected to the recovery pipeline on the inlet side of the discharge pump 2. Along the conveying direction of the fluid from left to right, the discharge acid discharge pipeline and the recovery pipeline are both inclined to the upper left and lower right.
2. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 1 is characterized in that The outsides of the discharging acid discharge pipeline and the recovery pipeline are both wrapped with heating pipelines.
3. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 2 is characterized in that The heating pipeline adopts copper pipe.
4. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 1, 2 or 3, characterized in that The inclination angle of the discharging acid discharge pipeline and the recovery pipeline is 5 to 10 degrees.
5. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 1, 2 or 3, characterized in that Valves are respectively connected in series on the discharging acid discharge pipeline and the recovery pipeline.
6. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 4 is characterized in that Valves are respectively connected in series on the discharging acid discharge pipeline and the recovery pipeline.
7. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 1, 2, 3 or 6, characterized in that A formaldehyde circulation pipeline is fixedly connected to a discharge acid discharge pipeline on an inlet side of a discharge pump.
8. The device for preventing the self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 4 is characterized in that A formaldehyde circulation pipeline is fixedly connected to a discharge acid discharge pipeline on an inlet side of a discharge pump.
9. The device for preventing self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 5, characterized in that A formaldehyde circulation pipeline is fixedly connected to a discharge acid discharge pipeline on an inlet side of a discharge pump.
10. The device for preventing self-polymerization and clogging of the acid discharge pipeline of the trioxymethylene concentration tower according to claim 8 or 9, characterized in that A valve is connected in series on the formaldehyde circulation pipeline.