Sampling system and sampling method in acrylamide production

Abstract

The invention belongs to the technical field of acrylamide production equipment, and relates to a sampling system and a sampling method in acrylamide production, the sampling system comprises a reaction kettle and a U-shaped main pipeline mounted on the reaction kettle, and further comprises a timer, the U-shaped main pipeline is sequentially provided with a circulating pump, a quantitative sampler and a flow meter along a feed liquid flowing direction, and the timer is connected with the reaction kettle. The U-shaped main pipeline is further provided with a one-way valve, the U-shaped main pipeline at the front end of the circulating pump is connected with an N2 pipeline, the N2 pipeline is provided with an N2 valve, and the N2 valve, the flowmeter, the quantitative sampler and the circulating pump are respectively connected with a timer. According to the sampling system, N2 pipeline purging, quantitative sampling and automatic interlocking are combined, automatic quantitative sampling is achieved through the quantitative sampler, human body contact is not needed, sampling is convenient, the labor intensity of workers is small, liquid in a pipeline is automatically emptied through N2 under automatic interlocking control after sampling is finished, pipeline blockage caused by acrylamide self-polymerization is effectively prevented, and the sampling efficiency is improved. The cost is low, and the anti-explosion, anti-aggregation and anti-poison effects are remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of acrylamide production equipment, and particularly relates to a sampling system and a sampling method in acrylamide production. Background Art

[0002] The biological method of preparing acrylamide is to mix raw water and immobilized biocatalyst into a hydrated solution, add acrylonitrile to carry out catalytic reaction, and separate the catalyst slurry after the reaction to obtain the desired acrylamide product. Its characteristics are: reaction at normal temperature and pressure, simple equipment, safe operation, enzyme specificity makes the selectivity extremely high and has no side reactions. However, before each test sampling, the medium that has not flowed in the tube must be released at the sampling port, otherwise it will lead to inaccurate test data and is not conducive to production adjustment.

[0003] The medium in the tube discharged before sampling should be recovered and processed, and the discharged acrylamide aqueous solution should be poured back into the recovery tank and treated together with the slurry, which wastes resources and energy.

[0004] In summer, the temperature is high, and the residual acrylamide medium in the pipe is easy to self-polymerize to produce polyacrylamide, thereby clogging the pipe, resulting in the inability to take samples in time, affecting the timeliness of production dynamic analysis.

[0005] The original medium acrylamide accumulated in the tube and the remaining unreacted highly toxic organic compound acrylonitrile discharged before detection sampling have potential neurotoxicity, genotoxicity and carcinogenicity, and can easily cause certain range of harm to human health.

[0006] Therefore, it is very necessary to develop an automatic sampling system for acrylamide water solution that combines effective pipeline chain anti-aggregation with self-circulation, vent-free and zero-contact anti-toxicity in the production of acrylamide. Summary of the invention

[0007] The purpose of the present invention is to provide a sampling system for acrylamide production to solve the problem of pipeline blockage caused by acrylamide self-polymerization in summer in the prior art, as well as the energy waste caused by medium discharge and the health impact of human contact.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a sampling system in acrylamide production, comprising a reactor and a U-shaped main pipe installed on the reactor, and also comprising a timer, wherein a circulation pump, a quantitative sampler and a flow meter are sequentially arranged along the flow direction of the feed liquid on the U-shaped main pipe, a one-way valve is also installed on the U-shaped main pipe, an N2 pipe is connected to the U-shaped main pipe at the front end of the circulation pump, an N2 pipe is arranged on the N2 pipe, and the N2 valve, the flow meter, the quantitative sampler and the circulation pump are respectively connected to the timer.

[0009] Furthermore, one end of the U-shaped main pipeline is communicated with the bottom of the reactor, and the other end of the U-shaped main pipeline is communicated with the upper part of the reactor.

[0010] Furthermore, one end of the U-shaped main pipe connected to the bottom of the reactor is a liquid inlet, and one end of the U-shaped main pipe connected to the upper part of the reactor is a liquid reflux outlet.

[0011] Furthermore, the one-way valve is provided with two groups, and the two groups of one-way valves are respectively installed on the U-shaped main pipe close to the liquid inlet and the liquid reflux outlet.

[0012] Furthermore, the quantitative sampler is installed on the horizontal section of the U-shaped main pipe and is arranged perpendicular to the horizontal section of the U-shaped main pipe.

[0013] Another object of the present invention is to provide a sampling method for a sampling system in acrylamide production, comprising the following steps:

[0014] (1) When sampling is required, the one-way valve and the circulation pump are opened, and the acrylamide liquid in the reactor enters the U-shaped main pipe through the bottom one-way valve under the action of the circulation pump. The flow meter is set to a certain flow rate. When the flow rate reaches the set value, the quantitative sampler automatically starts sampling, and the timer starts timing at the same time;

[0015] (2) When the sampling time reaches the sampling duration, the sampling is completed, the quantitative sampler is automatically closed, the circulating pump automatically stops running, the N2 valve is automatically opened, and the N2 in the N2 pipeline enters the U-shaped main pipeline to start N2 purging the pipeline;

[0016] (3) The residual acrylamide solution in the pipeline flows back to the reactor through the upper one-way valve under the action of N2. When the purge time reaches the purge time, the N2 valve automatically closes, the purge is completed, and the timer stops timing and returns to zero;

[0017] (4) After sampling is completed, the sample is sent for inspection. If the sample test result is unqualified, the sampling process continues. When the flow rate of the flow meter reaches the set value, the quantitative sampler automatically opens to continue sampling, and the timer automatically starts timing. When the sampling time is reached, the interlocked quantitative sampler automatically closes, and the interlocked N2 valve automatically opens to purge the pipeline with N2. When the timer reaches the purge time, the interlocked N2 valve automatically closes, and the interlocked timer stops timing. The purge is completed and the timer returns to zero;

[0018] (5) If the sample test results are qualified, the chain is terminated, the sampling process ends, and the discharge operation is carried out.

[0019] The present invention has the following beneficial effects: the sampling system of the present invention provides a combination of N2 pipeline purging, quantitative sampling and automatic interlocking. On the one hand, the quantitative sampling is realized by controlling the quantitative sampler through the automatic interlocking, without human contact, convenient sampling, low labor intensity for workers, effective anti-toxicity, health and energy saving; on the other hand, based on the self-polymerization characteristics of acrylamide and the possibility of an explosion caused by the unreacted highly toxic organic compound acrylonitrile remaining in the pipeline mixing with air to reach the explosion limit, N2 is used to replace the traditional air and combined with the automatic interlocking system. After the sampling is completed, the liquid in the pipeline is automatically emptied by N2 under the control of the automatic interlocking, and there is no need to empty the U-shaped main pipeline for sampling, and the pipeline blockage caused by the self-polymerization of acrylamide can be effectively prevented. The cost is low and the explosion-proof, anti-polymerization and anti-toxic effects are remarkable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the sampling system in the acrylamide production of the present invention.

[0021] In the figure, 1. U-shaped main line; 2. N2 valve; 3. N2 pipeline; 4. flow meter; 5. quantitative sampler; 6. one-way valve; 7. reactor; 8. timer; 9. circulation pump. DETAILED DESCRIPTION

[0022] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the protection scope of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the protection scope of the present invention.

[0023] like Figure 1 As shown, a sampling system for acrylamide production includes a reactor 7 and a U-shaped main line 1 installed on the reactor 7, and also includes a timer 8. A circulation pump 9, a quantitative sampler 5 and a flow meter 4 are sequentially arranged on the U-shaped main line 1 along the flow direction of the feed liquid. The quantitative sampler 5 is installed in the horizontal section of the U-shaped main line 1 and is vertically arranged with the horizontal section of the U-shaped main line 1; a one-way valve 6 is also installed on the U-shaped main line 1, and a N2 pipeline 3 is connected to the U-shaped main line 1 at the front end of the circulation pump 9, and the N2 pipeline 3 is externally connected to a N2 source. The N2 pipeline 3 is provided with a N2 valve 2, and the N2 valve 2, the flow meter 4, the quantitative sampler 5 and the circulation pump 9 are respectively connected to the timer 8.

[0024] When the flow meter 4 detects that the flow exceeds the set value, it can send a control signal to the timer 8 to adjust the working state of the timer 8. When the timer 8 detects that the time reaches the set value, it can send a control signal to the N2 valve 2 to adjust the N2 valve 2 and the timer 8 to start and stop automatically.

[0025] In order to improve the accuracy and intelligence of the system interlocking control, the N2 valve 2, the one-way valve 6, the circulation pump 9, the flow meter 4, the quantitative sampler 5 and the timer 8 are all connected to the controller, and the start and stop, parameter setting and feedback of each component are interlocked and controlled by the controller.

[0026] One end of the U-shaped main line 1 is connected to the bottom of the reactor 7, and the other end of the U-shaped main line 1 is connected to the upper part of the reactor 7. The end of the U-shaped main line 1 connected to the bottom of the reactor 7 is the liquid inlet, and the end of the U-shaped main line 1 connected to the upper part of the reactor 7 is the liquid reflux outlet. Two groups of one-way valves 6 are provided, and the two groups of one-way valves 6 are respectively installed on the U-shaped main line 1 near the liquid inlet and the liquid reflux outlet to prevent the liquid from flowing back.

[0027] The sampling method of the sampling system in acrylamide production includes the following steps:

[0028] (1) When sampling is required, the one-way valve 6 and the circulation pump 9 are opened, and the acrylamide liquid in the reactor 7 enters the U-shaped main pipe 1 through the bottom one-way valve 6 under the action of the circulation pump 9. The flow meter 4 is set to a certain flow rate. When the flow rate reaches the set value, the quantitative sampler 5 automatically starts sampling, and the timer 8 starts timing at the same time;

[0029] (2) When the sampling time reaches the sampling time, the sampling is completed, the quantitative sampler 5 is automatically closed, and the circulation pump 9 automatically stops running, the N2 valve 2 is automatically opened, and the N2 in the N2 pipeline 3 enters the U-shaped main pipeline 1 to start N2 purging the pipeline;

[0030] (3) The acrylamide solution remaining in the pipeline flows back to the reactor 7 through the upper one-way valve 6 under the action of N2. When the time reaches the purge time, the N2 valve 2 automatically closes, the purge is completed, and the timer 8 stops timing and returns to zero;

[0031] (4) After sampling is completed, the sample is sent for inspection. If the sample test result is unqualified, the sampling process continues. When the flow rate of the flow meter 4 reaches the set value, the quantitative sampler 5 automatically opens to continue sampling, and the timer 8 automatically starts timing. When the sampling time is reached, the interlocked quantitative sampler 5 is automatically closed, and the interlocked N2 valve 2 is automatically opened to purge the pipeline with N2. When the timer time reaches the purge time, the interlocked N2 valve 2 is automatically closed, and the interlocked timer 8 stops timing. The purge is completed and the timer is reset to zero;

[0032] (5) If the sample test results are qualified, the chain is terminated, the sampling process ends, and the discharge operation is carried out.

[0033] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0034] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A sampling system for acrylamide production, comprising a reactor and a U-shaped main pipe installed on the reactor, characterized in that: It also includes a timer. A circulation pump, a quantitative sampler and a flow meter are sequentially arranged along the flow direction of the slurry on the U-shaped main pipe. A one-way valve is also installed on the U-shaped main pipe. The U-shaped main pipe at the front end of the circulation pump is connected to an N2 pipeline. The N2 pipeline is provided with an N2 valve. The N2 valve, the flow meter, the quantitative sampler and the circulation pump are respectively connected to the timer.

2. The sampling system for acrylamide production according to claim 1, characterized in that: One end of the U-shaped main pipeline is communicated with the bottom of the reactor, and the other end of the U-shaped main pipeline is communicated with the upper part of the reactor.

3. The sampling system in acrylamide production according to claim 2, characterized in that: One end of the U-shaped main pipe connected to the bottom of the reactor is a liquid inlet, and one end of the U-shaped main pipe connected to the upper part of the reactor is a liquid reflux outlet.

4. The sampling system for acrylamide production according to claim 3, characterized in that: The one-way valves are provided in two groups, and the two groups of one-way valves are respectively installed on the U-shaped main pipe close to the liquid inlet and the liquid reflux outlet.

5. The sampling system in acrylamide production according to claim 1, characterized in that: The quantitative sampler is installed on the horizontal section of the U-shaped main pipeline and is vertically arranged with respect to the horizontal section of the U-shaped main pipeline.

6. The sampling system for acrylamide production according to any one of claims 1 to 5, characterized in that: The sampling method includes the following steps: (1) When sampling is required, the one-way valve and the circulation pump are opened, and the acrylamide liquid in the reactor enters the U-shaped main pipe through the bottom one-way valve under the action of the circulation pump. The flow meter is set to a certain flow rate. When the flow rate reaches the set value, the quantitative sampler automatically starts sampling, and the timer starts timing at the same time; (2) When the sampling time reaches the sampling duration, the sampling is completed, the quantitative sampler is automatically closed, the circulating pump automatically stops running, the N2 valve is automatically opened, and the N2 in the N2 pipeline enters the U-shaped main pipeline to start N2 purging the pipeline; (3) The residual acrylamide solution in the pipeline flows back to the reactor through the upper one-way valve under the action of N2. When the purge time reaches the purge time, the N2 valve automatically closes, the purge is completed, and the timer stops timing and returns to zero; (4) After sampling is completed, the sample is sent for inspection. If the sample test result is unqualified, the sampling process continues. When the flow rate of the flow meter reaches the set value, the quantitative sampler automatically opens to continue sampling, and the timer automatically starts timing. When the sampling time is reached, the interlocked quantitative sampler automatically closes, and the interlocked N2 valve automatically opens to purge the pipeline with N2. When the timer reaches the purge time, the interlocked N2 valve automatically closes, and the interlocked timer stops timing. The purge is completed and the timer returns to zero; (5) If the sample test result is qualified, the chain is terminated, the sampling process ends, and the discharge operation is carried out.

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