Alkali solution, as the basic raw material in the chemical industry, is widely used in core processes such as caustic soda production, chemical synthesis, wastewater treatment, electroplating degreasing, papermaking and pulp making. The stability of its concentration directly affects product quality, reaction efficiency, equipment life, and environmental compliance rate. Traditional manual sampling and testing have problems such as strong lag, large errors, and low safety, which can no longer meet the needs of modern chemical continuous, automated, and refined production.SJT-6000A Online Alkali Concentration MonitorWith its core advantages of real-time monitoring, precise analysis, and automatic feedback, it has become a key equipment for optimizing production processes, reducing operating costs, and ensuring safety in the chemical industry. Here is a detailed introduction:

1、 Core application scenarios and value

1. Production process of caustic soda (sodium hydroxide)

In the production of caustic soda using ion membrane and diaphragm methods, the concentration of alkali solution is the core indicator for measuring production efficiency. The online alkaline concentration monitor can monitor the alkaline concentration at the outlet of the electrolytic cell and the evaporation concentration process in real time (usually within the monitoring range of 10% -50%). By linking with the DCS system, it automatically adjusts the evaporation temperature, steam pressure, or feed rate to ensure that the concentration of the finished alkaline solution remains stable within the set range (such as 30%, 48%, or 50%). Not only does it avoid concentration exceeding the standard caused by manual adjustment lag, but it also reduces steam consumption and energy waste, while reducing the risk of equipment corrosion caused by concentration fluctuations and improving product qualification rate.

2. Chemical synthesis reaction process

In chemical synthesis processes such as acid-base neutralization, saponification reaction, and ester synthesis, alkaline solution is often used as a catalyst or reaction raw material, and its concentration directly affects the reaction rate and product purity. For example, in the production of synthetic detergents, coating additives, and pharmaceutical intermediates, online alkaline concentration monitors can track changes in alkaline concentration in the reaction system in real time. When the concentration is below a set threshold, the feeding system is automatically triggered to replenish alkaline to ensure that the reaction proceeds fully; When the reaction reaches the endpoint, timely feedback signals should be given to terminate the reaction, avoiding waste of raw materials and subsequent separation and purification pressure caused by excessive feeding. This application can increase the reaction conversion rate by 5% -10% and significantly reduce production costs.

3. Industrial wastewater treatment

In the treatment of chemical wastewater, alkaline solutions such as sodium hydroxide and calcium hydroxide are commonly used to neutralize acidic wastewater, adjust pH values, or as coagulants to assist in the precipitation of pollutants. The online alkaline concentration monitor can monitor the concentration of alkaline solution in the wastewater treatment tank in real time, and automatically adjust the amount of alkaline solution added based on the pH value and pollutant concentration data of the wastewater, avoiding the waste of alkaline solution and subsequent treatment burden caused by insufficient neutralization (wastewater pH not meeting the standard) or excessive addition. At the same time, real-time data recording can meet the traceability requirements of environmental protection departments for the treatment process, ensuring that wastewater discharge complies with the "Chemical Industry Water Pollutant Discharge Standards" and reducing the risk of environmental penalties.

4. Electroplating and surface treatment industry

In processes such as electroplating pretreatment (degreasing, oil removal) and anodizing, alkaline solution is used to remove oil stains and oxide layers on the surface of the workpiece. If the concentration is too high, it will cause corrosion of the workpiece, while if the concentration is too low, it will not achieve the desired treatment effect. The online alkaline concentration monitor can monitor the concentration of alkaline solution in the degreasing tank and degreasing tank in real time. When the concentration is lower than the set value, it automatically reminds the operator to replenish fresh alkaline solution or replace the tank solution, ensuring that the surface treatment quality of the workpiece is uniform and consistent, and reducing the rework rate caused by unqualified treatment. In addition, the device can withstand the interference of oil stains and impurities in the tank liquid, operate stably for a long time, and reduce the labor intensity and safety risks of manual testing.

5. Paper making and pulp bleaching process

In the pulp making process of the paper industry, alkaline solutions (such as sodium hydroxide and sodium sulfide solutions) are used to steam wood fibers, and their concentration directly affects pulp yield and fiber quality; In the bleaching process, alkaline solution is used to adjust the pH value of the bleaching solution to ensure the bleaching effect. The online alkaline concentration monitor can monitor the alkaline concentration at the outlet of the digester and the inlet of the bleaching tower in real time. By automatically adjusting the feed rate or dilution ratio, it ensures stable process parameters, improves pulp strength and whiteness, reduces alkaline consumption and black liquor discharge, and balances economic and environmental benefits.

2、 Product core technology advantages adapted to the needs of the chemical industry

The working conditions in the chemical industry are complex, with harsh conditions such as high temperature, high pressure, strong corrosion, multiple impurities, and high viscosity. The online alkaline concentration monitor has been specially optimized for these scenarios: using corrosion-resistant materials (such as polypropylene, PP, PTFE, Hastelloy) to contact the measured medium, it can withstand the corrosion of strong acids, strong alkalis, and organic solvents; Adopting non-contact measurement principles (such as refractive index method) or insertion based online detection technology to avoid the influence of medium adhesion and precipitation on the sensor and ensure long-term stable operation; Measurement accuracy can reach ± 0.1%, response time ≤ 2 seconds, meeting real-time control requirements; Support seamless integration of 4-20mA current signal and RS485 communication interface with DCS and PLC systems to achieve automated closed-loop control; Equipped with fault alarm, data storage, and historical curve query functions, it facilitates operators to trace and analyze production data.

3、 Application Summary

The SJT-6000A online alkaline concentration monitor fundamentally solves the pain points of traditional manual detection and achieves dynamic optimization of the production process by real-time, accurate, and automated monitoring of alkaline concentration in the core process of the chemical industry. Its application not only improves product quality stability and production efficiency, but also reduces raw material consumption, energy waste, and environmental risks, providing reliable technical support for chemical enterprises to achieve refined management and green low-carbon production. With the continuous improvement of automation and intelligence in the chemical industry, online alkaline concentration monitoring instruments will be widely used in more specialized fields and become key equipment for enterprises to enhance their core competitiveness.