Three-tank dosing device

• Product Overview

The three-box automatic dosing system is an integrated, automated solution developed by our company, combining chemical dissolution, maturation, storage, and precise dosing into a single unit. By housing these three functional zones—dissolution, maturation, and dosing—in separate compartments and incorporating an automated control system, this product provides a continuous, solution-stable, and highly automated solution for solid or liquid chemical dosing in water treatment processes, ensuring the continuity and stability of the dosing workflow.

• Structure and Working Principle

1. Core structural composition

The device adopts a three-box-in-one skid-mounted structure, typically organized in the following sequence:

• Dissolution box (one unit): Equipped with a powerful mechanical stirrer for rapid and thorough mixing and dissolution of solids (e.g., PAC, PAM) or high-concentration liquid agents with dilution water.
• Maturation chamber (two chambers): Equipped with a gentle agitator to provide sufficient residence time for the dissolved pharmaceutical solution, ensuring adequate maturation and activation to achieve optimal working condition (particularly critical for high-molecular-weight flocculants).
• Dosage tank (three tanks, also known as storage tanks): Stores pre-matured standby solutions and is equipped with a level gauge. The clear solution inside the tank is precisely delivered externally via metering pumps.
• Automatic control system: The core control unit typically includes a PLC controller, level sensors, a starter-stop logic for the agitator, and a metering pump control module, enabling level linkage and automatic liquid replenishment.
• Delivery system: Primarily composed of precision metering pumps (e.g., mechanical diaphragm pumps), pulse dampers, safety valves, backpressure valves, and pipelines, responsible for the stable and accurate dosing of the medicinal solution.

2. Working Principle

The device operates under an automated workflow featuring continuous dissolution, stepwise maturation, and constant liquid level dosing.

1. Automatic dosing: When the liquid level in the dosing tank drops to the low point, the control system automatically activates. The inlet valve and the agitator in the dissolution tank are sequentially opened, and solid reagents can be automatically added via the dry hopper (optional), completing the initial dosing in the dissolution tank.
2. Stepwise maturation: The initially dissolved medicinal solution overflows or is transferred through a transfer pump into the maturation chamber for continued stirring and maturation, then overflows into the dosing chamber for standby, forming a continuous liquid flow path across three chambers to ensure a constant supply of matured medicinal solution.
3. Continuous dosing: The metering pump draws the solution from the dosing tank based on external signals (e.g., 4-20mA flowmeter signal or PLC command) and delivers it precisely and continuously to the dosing point. The entire process is automatically monitored and managed by the PLC.

• Core technical features

1. Three-box separation ensures solution quality: The independent functions of dissolution, maturation, and storage prevent partially dissolved or immature agents from directly entering the dosing system, thereby ensuring the uniformity and optimal efficacy of the dosed solution. This is particularly effective for high-molecular-weight polymer agents.
2. Continuous automated operation: The automatic control based on liquid level linkage achieves fully automated continuous operation from drug preparation to dosing, reducing the intermittency and instability of manual operations, which is conducive to the long-term stable operation of the process.
3. Accurate and reliable dosing: The system employs high-quality mechanical diaphragm metering pumps paired with intelligent control systems, enabling proportionate or precise dosing based on water quality and flow rate variations. This facilitates optimized chemical consumption and cost-effective treatment.
4. Compact structure for easy management: The skid-mounted integrated design occupies minimal space, requiring only connection of water and electricity supply pipelines on-site. The centralized control interface provides clear visibility of operational status, facilitating convenient management and maintenance.
5. Corrosion-resistant materials with strong adaptability: The main components of the device that come into contact with chemical solutions (such as the tank, pipelines, and pump heads) can be made of corrosion-resistant materials like PE, PP, PVC, or stainless steel 304/316L, to withstand various chemicals including acids, alkalis, salts, and oxidizers.

• Main technical parameters

• Typical Application Fields

This device is widely applicable to scenarios requiring continuous and precise dosing of various water treatment chemicals.

• Coagulation and sedimentation process: This method involves adding coagulants such as polyaluminum chloride (PAC) and polyferric sulfate (PFS).
• Flocculation and sludge dewatering: Used for preparing and adding flocculants such as polyacrylamide (PAM).
• Disinfection and oxidation: Used for adding disinfectants or oxidizers such as sodium hypochlorite, sodium chlorite, and hydrogen peroxide.
• pH adjustment: used for adding neutralizing agents such as sodium hydroxide, sulfuric acid, and hydrochloric acid.
• Circulating water treatment: for adding corrosion inhibitors, scale inhibitors, bactericides, etc.
• Other applications: Specific chemical dosing in industries such as power plant desulfurization wastewater, chemical processes, and food processing.