Closed Loop Cooling Tower Water Treatment System

In a closed loop cooling tower water treatment system, although water treatment is not as complex as in an open system, it is still crucial. The following are the core requirements for water treatment in closed-loop cooling systems, which help prevent corrosion, scaling, biological pollution, and ensure long-term efficient operation of the system.

1、 The main goal of closed loop cooling tower water treatment system

1. Corrosion prevention: prevent carbon steel, stainless steel, copper and other metal pipelines from being corroded.

2. Anti scaling: Control the calcium and magnesium ions in water to prevent the formation of scale.

3. Inhibit microbial growth: prevent the growth of bacteria and algae, and avoid biofilm blockage.

4. Stable water quality: Maintain long-term water quality stability and reduce maintenance frequency.

5. Control pH value: Maintain it within an appropriate range to prevent metal corrosion or precipitation.

2、 Specific requirements for closed loop cooling tower water treatment system

1. Initial filling water quality requirements

Use softened water or deionized water (DI water) to avoid excessive hardness and TDS.

Filter out suspended impurities (recommended filtration accuracy: ≤ 10 microns).

Control the dissolved oxygen in the water and recommend deoxygenation treatment for the initial water injection.

2. Corrosion inhibitor addition (anti-corrosion)

Carbon steel system: commonly used sodium nitrite and molybdate.

Copper containing system: Add copper corrosion inhibitors such as Tolyltriazole (TTA).

Aluminum material system: Pay attention to pH control (excessive pH can corrode aluminum)

3. pH control

Recommended pH value: 8.0-10.0 (depending on the material).

Add buffering agents (such as borates and phosphates) to stabilize the pH and prevent severe fluctuations.

Attention: Low pH can easily corrode copper, while high pH can easily form scaling.

4. Addition of ethylene glycol or propylene glycol (if antifreeze is required)

Add antifreeze when needed in northern regions or during winter.

Use an industrial grade ethylene glycol/propylene glycol solution containing corrosion inhibitors (with regular concentration and pH testing required).

Do not use automotive coolant.

3、Closed loop cooling tower water treatment system operation and maintenance precautions

1. Thoroughly rinse the system before the initial startup to remove impurities such as welding slag and oil stains.

2. It is prohibited to use untreated tap water for replenishment.

3. Record the trend of changes in water quality parameters to facilitate early detection of problems.

4. Pressure expansion tank and sealing inspection to prevent air from entering.

5. Occasional water addition must ensure that it is treated soft water or additive water.