Brine concentration on-line analyzer adopting refraction method

Abstract

The utility model relates to a refraction method saline concentration on-line analyzer, which comprises an explosion-proof analyzer controller and an explosion-proof field detection probe which are connected through a cable, the explosion-proof analyzer controller comprises a signal acquisition and processing module, a signal output module, a display and operation module, a control module and a power supply module, and circuit boards of the modules are arranged in a shell of the explosion-proof analyzer controller in a layered manner; the explosion-proof field detection probe comprises a prism, a high-intensity light source, a photoelectric conversion module, a temperature element, an automatic cleaning unit, a power supply and a signal acquisition and amplification circuit. The device disclosed by the utility model can be directly immersed in a sodium chloride solution for measurement and is not corroded by chloride salt liquid; compared with an original conductivity method, the refraction method for measuring the response time is shorter, the measurement precision is higher, and the stability is higher; the liquid receiving surface of the prism of the detection probe is obliquely arranged, so that the interference caused by the fact that bubbles entrained in the liquid adsorb the liquid receiving surface of the prism is effectively avoided; the analyzer has an automatic cleaning function, so that the accuracy and the stability of the analyzer are further guaranteed while a large amount of labor cost is saved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of analysis appearance, concretely relates to the on -line monitoring device for sodium chloride solution concentration in chlor alkali industrial production. BACKGROUND

[0002] In chlor alkai industry, ion exchange membrane method makes alkali technology, with the advantages such as large capacity, high quality, low energy consumption and small pollution, is the most advanced chlor alkali production process in the industry. Its technical principle is to use the selective permeability of chlor alkali ion exchange membrane, and the Na+ ion and a small amount of water produced by the electrolysis of the refined NaCl solution injected into the anode chamber flow to the cathode chamber through the cation exchange membrane, and the OH- produced by the water electrolysis in the cathode chamber (cannot pass through the ion membrane and gather in the cathode chamber) to form NaOH solution.

[0003] Ion exchange membrane is composed of sulfonic acid layer and carboxylic acid layer, and water will migrate from the anode chamber to the cathode chamber during electrolysis. The concentration of anode NaCl solution is extremely sensitive to the amount of water migration. When the concentration of anode NaCl solution is low, the amount of water migration increases. Due to the difference in hydrophilicity of the two layers of ion membrane, the hydrophilicity of the sulfonic acid layer is greater than that of the carboxylic acid layer. Excessive water migrates through the sulfonic acid layer without passing through the carboxylic acid layer, which is blocked by the carboxylic acid layer, causing the deformation of the ion membrane interface. Long-term operation under this condition will inevitably cause damage to the expensive ion membrane and even cause the system to shut down. When the concentration of anode NaCl solution is too high, the conductivity of the solution fluctuates greatly, causing the cell voltage to rise and increasing the energy consumption. At the same time, sodium chloride is easy to crystallize and precipitate under high concentration, which adheres to the ion membrane and electrolytic cell, hinders the migration of Na+ ion, and causes the permeability of ion membrane to decrease or even damage the ion membrane. Therefore, the control of the concentration of anode NaCl solution in the electrolytic cell is crucial to the service life of the ion membrane and the stable operation of the process. SUMMARY

[0004] The utility model discloses a kind of sodium chloride solution online analyzers of high measurement accuracy, fast response speed, stable performance and with self-cleaning function for chemical production device.

[0005] The main technical scheme of the utility model discloses is: a refractometry brine concentration on-line analyzer, characterized in that, including the explosion-proof analyzer controller and explosion-proof field detection probe connected by cable;

[0006] The explosion-proof analyzer controller includes a signal acquisition and processing module, a signal output module, a display and operation module, a control module and a power module. The circuit boards of each module are layered in the explosion-proof analyzer controller housing.

[0007] The explosion-proof field detection probe includes a prism, a high-intensity light source, a photoelectric conversion module, a temperature element, an automatic cleaning unit, a power supply, and a signal acquisition and amplification circuit. The prism and temperature element are placed at the top of the explosion-proof field detection probe. The prism is installed at an angle to the surface of the liquid being tested, and the sleeve of the temperature element extends into the liquid being tested. The light emitted by the high-intensity light source forms a 90° angle with the incident surface of the prism. The automatic cleaning unit includes a cleaning pipeline, a one-way valve, and a solenoid valve. The outlet of the cleaning pipeline faces the liquid contact surface of the prism.

[0008] Generally, the cable adopts a top-bottom structure, with the power lines, signal lines, and control lines having separate shielding layers.

[0009] Except for the liquid-contacting surface of the prism, the other liquid-contacting parts of the explosion-proof field detection probe are made of Hastelloy C with PTFE lining.

[0010] The angle between the liquid contact surface of the prism of the explosion-proof field detection probe and the flow direction of the solution being tested is 45°.

[0011] The temperature element sleeve of the explosion-proof field detection probe has a cylindrical protrusion at the top, protruding 5mm from the top of the probe.

[0012] The high-intensity light source of the explosion-proof field testing probe is a semiconductor laser light source.

[0013] The photoelectric conversion module of the explosion-proof field detection probe adopts a CCD photoelectric acquisition device.

[0014] The cleaning medium of the explosion-proof on-site detection probe automatic cleaning unit is purified compressed air or deionized water.

[0015] The explosion-proof field detection probe is equipped with a connecting flange, which can be connected to a bypass flow tank or short-connected to the flange and inserted into the process pipeline.

[0016] The explosion-proof analyzer controller signal output module outputs 4-20mADC analog signals and RS-485 digital signals respectively.

[0017] This invention allows for direct immersion in sodium chloride solution for measurement, unaffected by corrosion from chloride-containing liquids. The refractive index method provides a shorter response time compared to the traditional conductivity method, resulting in higher accuracy and stability. The tilted placement of the probe prism at the liquid surface effectively prevents air bubbles trapped in the liquid from adsorbing onto the prism and causing interference. The built-in automatic cleaning function saves significant labor costs while further ensuring the accuracy and stability of the analyzer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the online saline concentration analyzer based on the refractive index method according to an embodiment of this utility model.

[0019] In the figure: 1 - explosion-proof analyzer controller; 2 - explosion-proof field detection probe; 21 - prism; 22 - light source and photoelectric conversion module; 23 - temperature element; 24 - cleaning pipeline; 25 - connecting flange; 26 - one-way valve; 27 - electromagnetic valve; 28 - power supply and signal acquisition amplification circuit. DETAILED DESCRIPTION

[0020] The utility model will be described in detail below in combination with the drawings and examples. EXAMPLE

[0021] A refractometry brine concentration on-line analyzer for measuring the concentration of sodium chloride solution in industrial production.

[0022] The refractometry brine concentration on-line analyzer of the embodiment refers to the attached Figure 1 , mainly including explosion-proof analyzer controller (1) and explosion-proof field detection probe (2) connected through cable; the explosion-proof analyzer controller (1) includes signal acquisition and processing module, signal output module, display and operation module, control module, power module, and the circuit board of each module is layered in the shell of explosion-proof analyzer controller (1); the explosion-proof field detection probe (2) includes prism (21), high-strength light source and photoelectric conversion module (22), temperature element (23), automatic cleaning unit, power supply and signal acquisition amplification circuit (28); the prism (21) and temperature measuring element (23) are placed at the top of explosion-proof field detection probe (2), the prism (21) is installed with the inclined surface of contact with the measured liquid, the temperature measuring element (23) sleeve extends into the measured liquid, and the high-strength light source emits light with the prism incident surface at 90° angle; the automatic cleaning unit includes cleaning pipeline (24), one-way valve (26) and electromagnetic valve (27), the outlet of cleaning pipeline (24) is opposite the prism (21) liquid contact surface, and the electromagnetic valve (27) is controlled by explosion-proof analyzer controller (1) through cable.

[0023] In the embodiment, the cable adopts total and partial structure, and the shielding layers of power lines, signal lines and control lines are classified and independently shielded.

[0024] In the embodiment, the material of the liquid contact part of explosion-proof field detection probe (2) except the prism liquid contact surface is Hastelloy C with PTFE lining; the prism liquid contact surface and the measured solution flow direction angle are 45°, the top of temperature element sleeve is cylindrical protruding shape, and the top of protruding probe is 5mm.

[0025] In the embodiment, the high-strength light source of explosion-proof field detection probe (2) adopts semiconductor laser light source, and the photoelectric conversion module adopts CCD photoelectric collector.

[0026] In the embodiment, the cleaning medium of the automatic cleaning unit of the explosion-proof field detection probe (2) is purified compressed air or deionized water, and the electromagnetic valve (27) is connected to the purified instrument air or deionized water at the inlet.

[0027] In the embodiment, the explosion-proof analyzer controller (1) is connected to a 220VAC power supply, and simultaneously supplies power to the explosion-proof field detection probe (2); the signal output module of the explosion-proof analyzer controller (1) respectively outputs 4-20mADC analog signals and RS-485 digital signals.

[0028] The working process of the embodiment is as follows: the explosion-proof field detection probe (2) is connected to the flow cell or the process pipeline flange short circuit through the connecting flange (25) and is installed in the process pipeline, and the top end of the probe is immersed in the measured liquid.

[0029] The light emitted by the semiconductor laser emitter in the light source and photoelectric conversion module (22) is refracted at the liquid surface of the prism (21), the refracted light is transmitted into the light source and photoelectric conversion module (22), is received by the photoelectric converter, and is converted into an electric signal, which is collected by the power supply and signal collection and amplification circuit (28), and the temperature signal value of the temperature element (23) is collected at the same time, after the two groups of signals are amplified and processed, the signals are transmitted to the data calculation processing, and the measurement value is displayed on the display screen of the explosion-proof analyzer controller (1), and the result can be transmitted to the DCS system.

[0030] The automatic cleaning process is as follows: the explosion-proof analyzer controller (1) sets the automatic cleaning time interval, after the setting is completed, enters the countdown state; after the interval time, the explosion-proof analyzer controller (1) opens the electromagnetic valve (27) to clean the instrument air or deionized water once, the instrument air or deionized water passes through the electromagnetic valve (27), the check valve (26) and the cleaning pipeline (24) to flush the liquid surface of the prism (21), after the flushing is completed, enters the next countdown period.

[0031] The unmentioned part of the embodiment is the technology well known in the art.

Claims

1. An on-line refractometric brine concentration analyzer characterized by, The explosion-proof analyzer controller and the explosion-proof field detection probe are connected by a cable; the explosion-proof analyzer controller comprises a signal acquisition and processing module, a signal output module, a display and operation module, a control module, and a power module, and the circuit boards of each module are layered in the explosion-proof analyzer controller shell; The explosion-proof field detection probe comprises a prism, a high-intensity light source, a photoelectric conversion module, a temperature element, an automatic cleaning unit, a power supply, and a signal acquisition and amplification circuit; the prism and the temperature measuring element are arranged at the top end of the explosion-proof field detection probe, the prism is installed obliquely on the contact surface with the measured liquid, the temperature measuring element sleeve extends into the measured liquid, and the high-intensity light source emits light at a 90° angle with the prism incident surface; the automatic cleaning unit comprises a cleaning pipeline, a one-way valve, and an electromagnetic valve, and the outlet of the cleaning pipeline is opposite to the prism liquid contact surface.

2. The refractometric brine concentration on-line analyzer of claim 1, wherein The cable adopts a total and partial structure, and the power line, signal line, and control line shielding layers are classified and independently shielded.

3. The refractometric brine concentration on-line analyzer of claim 1 wherein The material of the liquid contact part of the explosion-proof field detection probe, except the prism liquid contact surface, is Hastelloy C with PTFE lining.

4. The refractometric brine concentration on-line analyzer of claim 2 wherein The angle between the prism liquid contact surface of the explosion-proof field detection probe and the flow direction of the measured solution is 45°.

5. The refractometric brine concentration on-line analyzer of claim 1 wherein The top end of the temperature element sleeve of the explosion-proof field detection probe is in a cylindrical protruding shape, and the protruding probe top end is 5 mm.

6. The refractometric brine concentration on-line analyzer of claim 1 wherein The high-intensity light source of the explosion-proof field detection probe adopts a semiconductor laser light source.

7. The refractometric brine concentration on-line analyzer of claim 1 wherein The photoelectric conversion module of the explosion-proof field detection probe adopts a CCD photoelectric collector.

8. The refractometric brine concentration on-line analyzer of claim 1 wherein The cleaning medium of the automatic cleaning unit of the explosion-proof field detection probe is purified compressed air or deionized water.

9. The refractometric brine concentration on-line analyzer of claim 1 wherein The explosion-proof field detection probe is provided with a connecting flange, which can be connected with a bypass flow cell or connected with a flange short connection to insert into a process pipeline.

10. The refractometric brine concentration on-line analyzer of claim 1 wherein The signal output module of the explosion-proof analyzer controller outputs 4-20 mADC analog signals and RS-485 digital signals respectively.

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