Pretreatment device for online detection

Abstract

The utility model discloses a pretreatment device for online detection. The pretreatment device comprises an oil-water mixer (1), a nano microporous membrane tube (2) arranged in the oil-water mixer (1) and a coalescer (3), wherein a liquid inlet of the coalescer (3) is communicated with a liquid outlet of the oil-water mixer (1); a liquid collecting bag (4) is arranged at the top of the coalescer (3), and a water outlet pipe (5) is arranged at the bottom of the coalescer (3); the pH sensor (6) is used for detecting the pH value of liquid in the water outlet pipe (5); a liquid inlet of the oil-water mixer (1) is communicated with a pure water pipe, and a liquid inlet of the nano microporous membrane pipe (2) is communicated with a sampling medium supply pipe. According to the technical scheme provided by the utility model, the pH value of the raffinate after the alkali liquor is treated and regenerated is detected in real time, and whether the addition amount of the alkali liquor in the production process is reasonable or not is monitored, so that the pH value of a working solution is effectively controlled, and the risk that the device is out of control is eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen peroxide production, in particular to a pretreatment device for on-line detection. Background Art

[0002] Hydrogen peroxide aqueous solution, also known as hydrogen peroxide, is an important raw material for producing peroxides such as peracetic acid and thiourea peroxide, and is widely used in industries such as medicine, textile printing and dyeing, and paper bleaching. At present, the anthraquinone method is commonly used. The anthraquinone method mainly includes a hydrogenation process, an oxidation process, an extraction process, and a post-treatment process. Its production principle is that alkyl anthraquinone is dissolved in an organic solvent to form a working solution. In the hydrogenation process, the alkyl anthraquinone in the working solution is hydrogenated to form anthrahydroquinone under the action of a catalyst; in the oxidation process, the hydrogenated solution containing anthrahydroquinone is oxidized by air to generate H2O2 and anthraquinone; in the extraction process, pure water is used to extract H2O2 in the working solution to obtain an aqueous hydrogen peroxide solution; in the post-treatment process, the raffinate is dehydrated, regenerated and then returned to the hydrogenation process to start the next cycle.

[0003] The main purpose of setting the post-treatment process is to decompose hydrogen peroxide in the raffinate, remove water in the working solution and regenerate some degraded substances. The working solution is mainly treated by dehydration, alkali solution treatment regeneration (decomposing H2O2), activated alumina regeneration and other methods. The traditional post-treatment process flow is: the raffinate first passes through a raffinate separator, and part of its free water is separated. Then the raffinate passes through a drying tower containing potassium carbonate solution, where most of the water is adsorbed, most of the hydrogen peroxide is decomposed and some degraded substances are regenerated. Then it passes through an alkali settler to remove the alkali solution entrained in the working solution, and then enters a clay bed. After the water and hydrogenated degraded substances are adsorbed by the activated alumina in the clay bed, it reaches the circulating working solution tank to start the next cycle.

[0004] If the pH value of the working solution cannot be effectively controlled during the production process, it is easy to cause the device to get out of control (the oxidation solution is alkaline, causing the decomposition of hydrogen peroxide), and there are certain potential safety hazards. Therefore, it is of great significance to strengthen the detection of the pH value and H2O2 content of the working solution in the post-treatment process. The existing detection method is to mix the working solution and pure water, stir evenly, then separate the oil and water by centrifugal separation, and then detect the pH value and H2O2 content of the water. There are problems such as inability to continuously detect and lag in detection results. Summary of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide a pretreatment device for on-line detection, which can effectively detect the pH value and H2O2 content of the working solution in the post-treatment process in real time and eliminate potential safety hazards.

[0006] To solve the above technical problems, the present utility model provides a pretreatment device for on-line detection, including an oil-water mixer, a nano-porous membrane tube disposed in the oil-water mixer, and a coalescer with an inlet connected to the outlet of the oil-water mixer; a liquid collection bag is provided at the top of the coalescer, and a water outlet pipe is provided at the bottom of the coalescer; a pH sensor for detecting the pH value of the liquid in the water outlet pipe is also provided; the inlet of the oil-water mixer is connected to a pure water pipe, and the inlet of the nano-porous membrane tube is connected to a sampling medium supply pipe.

[0007] In one embodiment, the pretreatment device for on-line detection provided by the present utility model further has a sensor for detecting the hydrogen peroxide concentration of the liquid in the water outlet pipe.

[0008] In one embodiment, the pretreatment device for on-line detection provided by the present utility model further has a filter disposed on the inlet pipeline of the nano-porous membrane tube.

[0009] In one embodiment, for the pretreatment device for on-line detection provided by the present utility model, a first flow meter and a first control valve are provided on the inlet pipeline of the oil-water mixer, and a second flow meter and a second control valve are provided on the inlet pipeline of the nano-porous membrane tube.

[0010] In one embodiment, for the pretreatment device for on-line detection provided by the present utility model, the oil discharge port of the liquid collection bag is connected to the sampling medium delivery pipe through a pipeline.

[0011] Without conflict, the foregoing improved technical solutions can be implemented alone or in combination.

[0012] The technical solution provided by the present utility model can effectively control the acidity and alkalinity of the working fluid and eliminate the risk of device out-of-control by detecting the pH of the raffinate after alkali treatment regeneration in real time and monitoring whether the addition amount of alkali liquor in the production process is reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings are used to provide a further understanding of the present utility model, and constitute a part of this application. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model, but do not constitute an improper limitation to the present utility model. In the drawings:

[0014] Figure 1 It is a structural diagram of the pretreatment device for on-line detection in the embodiment. EMBODIMENTS

[0015] The following further describes in detail the specific embodiments of the present utility model with reference to the drawings.

[0016] As Figure 1The preprocessing device for on-line detection shown in the figure includes an oil-water mixer 1, a nano-porous membrane tube 2 arranged in the oil-water mixer 1, and a coalescer 3 with an inlet communicating with the outlet of the oil-water mixer 1; a liquid collection bag 4 is arranged at the top of the coalescer 3, and a water outlet pipe 5 is arranged at the bottom of the coalescer 3; it also has a pH sensor 6 for detecting the pH value of the liquid in the water outlet pipe 5; the inlet of the oil-water mixer 1 is communicated with a pure water pipe, and the inlet of the nano-porous membrane tube 2 is communicated with a sampling medium supply pipe. In the embodiment, the nano-porous membrane tube 2 is made of polyvinylidene fluoride material with a pore diameter of 5 μm, and the pH sensor 6 is selected as Mettler 3250i.

[0017] In the technical solution provided by the present utility model, the sampling medium (oily liquid, which is the raffinate after the treatment and regeneration of the lye in the production process of anthraquinone hydrogen peroxide in the embodiment) diffuses into the oil-water mixer 1 through the nano-porous membrane tube 2. After the sampling medium and pure water are mixed evenly in the oil-water mixer 1, they flow into the coalescer 3, where oil-water separation is carried out. The oily liquid (the raffinate after the treatment and regeneration of the lye in the embodiment) is discharged from the liquid collection bag 4 at the top of the coalescer 3, and the pure water and the substances dissolved in the pure water are discharged from the water outlet pipe 5 at the bottom of the coalescer 3. The pH is detected in real time by the pH sensor 6 arranged on the water outlet pipe 5, and the acidity and alkalinity of the regenerated working fluid are indirectly detected, monitoring whether the addition amount of the lye is reasonable, effectively controlling the acidity and alkalinity of the working fluid, and eliminating the risk of device out-of-control. When it is not necessary to preprocess the working fluid, by sampling and analyzing the water quality discharged from the water outlet pipe 5, the pH value and H2O2 content of the working fluid in the post-treatment process can be detected in real time, which is beneficial to eliminating potential safety hazards.

[0018] As Figure 1 shown, as one of the embodiments, on the basis of the foregoing basic solution, the preprocessing device for on-line detection further has a sensor 7 for detecting the hydrogen peroxide concentration of the liquid in the water outlet pipe 5. In the embodiment, the sensor 7 for hydrogen peroxide concentration is selected as the CAS-7 sensor.

[0019] By detecting the content of hydrogen peroxide in the raffinate after the treatment and regeneration of the lye in real time, monitoring whether the addition amount of the lye in the production process is reasonable, effectively controlling the acidity and alkalinity of the working fluid, and eliminating the risk of device out-of-control.

[0020] As Figure 1 shown, as one of the embodiments, on the basis of the foregoing basic solution, the preprocessing device for on-line detection further has a filter 8 arranged on the inlet pipeline of the nano-porous membrane tube 2. Setting the filter 8 can remove solid impurities in the raffinate after the treatment and regeneration of the lye, reducing the blockage of the nano-porous membrane tube 2.

[0021] As Figure 1As shown, as one of the embodiments, on the basis of the foregoing basic solution, for the pretreatment device for on-line detection, a first flowmeter and a first control valve are provided on the liquid inlet pipeline of the oil-water mixer 1, and a second flowmeter and a second control valve are provided on the liquid inlet pipeline of the nano-microporous membrane tube 2. The first flowmeter and the first control valve measure and control the flow rate of pure water entering the oil-water mixer 1, and the second flowmeter and the second control valve measure and control the flow rate of the oily medium entering the oil-water mixer 1, so as to maintain the stability of the mixing ratio of the two and avoid affecting the detection result.

[0022] As Figure 1 As shown, as one of the embodiments, on the basis of the foregoing basic solution, for the pretreatment device for on-line detection, the oil discharge port of the liquid collection bag 4 is communicated with the sampling medium delivery pipe through a pipeline. The optional solution is to reuse the pipeline downstream of the inlet of the sampling pipeline, which does not affect the sampling of the sampling medium and can recover the oily medium at the same time.

[0023] The foregoing are only the preferred embodiments of the present invention and do not limit the present invention in any way. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preprocessing device for online detection, characterized in that: The invention comprises an oil-water mixer (1), a nano-microporous membrane tube (2) arranged in the oil-water mixer (1), and a coalescer (3) whose liquid inlet is connected to the liquid outlet of the oil-water mixer (1); a liquid collecting bag (4) is arranged on the top of the coalescer (3), and a water outlet pipe (5) is arranged on the bottom of the coalescer (3); and a pH sensor (6) is provided for detecting the pH value of the liquid in the water outlet pipe (5); the liquid inlet of the oil-water mixer (1) is connected to a pure water pipe, and the liquid inlet of the nano-microporous membrane tube (2) is connected to a sampling medium supply pipe.

2. The preprocessing device for online detection according to claim 1, characterized in that: It also has a sensor (7) for detecting the concentration of hydrogen peroxide in the liquid in the water outlet pipe (5).

3. The preprocessing device for online detection according to claim 1, characterized in that: It also has a filter (8) arranged on the liquid inlet pipeline of the nano-microporous membrane tube (2).

4. The preprocessing device for online detection according to claim 1, characterized in that: The liquid inlet pipeline of the oil-water mixer (1) is provided with a first flow meter and a first control valve, and the liquid inlet pipeline of the nano-microporous membrane tube (2) is provided with a second flow meter and a second control valve.

5. The preprocessing device for online detection according to claim 1, characterized in that: The oil discharge port of the liquid collecting bag (4) is connected to the sampling medium delivery pipe through a pipeline.

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