Overview of Applications After Full-Automatic Chemical Dosing Systems Are Put into Use

As quality control requirements for industrial circulating water, central air-conditioning water, and wastewater treatment projects continue to rise, the drawbacks of traditional manual chemical dosing—difficult dosage control, serious chemical waste, and operational safety risks—have become increasingly apparent. As an integrated water treatment auxiliary system, the fully automatic dosing device, with its advantages of automatic chemical preparation, precise dosing, and stable operation, has become the preferred equipment for water quality operation and maintenance in numerous engineering projects. With a high degree of integration and easy installation, it can greatly reduce on-site labor after commissioning and ensure long-term stable compliance with water quality standards.

The Meijie fully automatic dosing device uses a metering pump as its core dosing unit, and the entire system relies on a PLC intelligent control cabinet to achieve fully automatic closed-loop control. The operator puts solid or liquid chemicals into the dissolving tank and mixes them to a preset concentration. Once prepared, the chemical solution is stored in the storage tank. A liquid level sensor monitors the chemical solution level in real time; at low level, the water refilling and chemical mixing process is automatically triggered, and at high level, water inlet stops automatically to prevent overflow.

The system can collect water quality signals such as circulating water flow, pH, and conductivity, and automatically adjust the metering pump's output frequency and stroke to precisely dose the chemical solution into the system pipeline at the set ratio. After the chemicals enter the water, chemical reactions occur, achieving scale inhibition, corrosion inhibition, sterilization and algae removal, flocculation and sedimentation, and pH adjustment. The equipment has built-in protection mechanisms: when the metering pump fails, chemicals run out, or pipelines are blocked, the control system automatically alarms and shuts down to prevent equipment damage. The entire process requires no continuous manual supervision, achieving 24-hour continuous and stable dosing.

The fully automatic dosing device adopts a skid-mounted integrated design, with all components mounted on the same base, mainly consisting of four major units:

Chemical dissolving and storage unit: includes dissolving tank and storage tank, available in PE anti-corrosion plastic or 304/316 stainless steel, with high/low level gauges for real-time monitoring of chemical inventory;

Metering and dosing unit: metering pump, drain valve, check valve, back-pressure valve, pressure gauge, ensuring quantitative and stable chemical delivery, preventing backflow, and protecting the metering pump;

Automatic control unit: PLC control cabinet, sensors, and alarm module, supporting automatic/manual dual-mode switching, with low-chemical, overload, and fault alarm functions, and can connect to remote control systems.

HVAC circulating water systems: central air-conditioning closed cooling water and chilled water, dosing scale inhibitors, corrosion inhibitors, and biocides to prevent scaling and corrosion of pipelines and condensers;

Industrial circulating water systems: factory production circulating cooling water, protecting heat exchangers and pipelines and reducing equipment cleaning frequency;

Wastewater treatment projects: dosing PAC and PAM flocculants and pH adjusters at wastewater stations for coagulation, sedimentation, and pH adjustment;

Boiler feedwater systems: dosing oxygen scavengers and scale inhibitors into boiler water to prevent boiler scaling and corrosion;

Tap water and pure water pretreatment: dosing disinfectants and flocculants to ensure product water quality;