Sediment and problems caused by it in facilities

What is scale and how is it formed?

When water is used as a thermal fluid, the salts and hardness in the water are separated due to temperature shock and settle on the surfaces, forming scale. These scales are one of the most important factors of erosion and corrosion in heating and refrigeration facilities. In addition to causing erosion and corrosion, the presence of scales also wastes a significant amount of energy due to lack of heat exchange and reduces the efficiency of the facility.

Scales are a factor in energy loss

The effect of scale on energy loss is a topic that has received more attention today, so that the annual cost of energy loss due to scale in industries, facilities, equipment, pipes, etc. is estimated to be $45 billion in all countries, which is equivalent to 0.2% of the world's net production.

Scale formation in boilers and heat exchangers

As the concentration of dissolved and suspended solids and materials in the water of boilers, heat exchangers, etc. increases, the possibility of scale formation increases.

The cause of sediment formation in water:

1. The concentration of dissolved substances and particles in water, which forms sediment with increasing temperature and saturation of ions.
2. Suspended substances in water, which can be caused by corrosion products, airborne particles, or the growth of microorganisms in water.

The factors affecting the formation of an adhesive sediment layer are:

1. Fluid temperature and heating surface…
2. Fluid velocity
3. Size and composition of particles in the fluid
4. Fluid passage time

Disadvantages and problems caused by sediment formation:

The presence of sediment causes a decrease in the internal diameter of pipes and, as a result, a decrease in water flow. Also, sediment acts as a thermal insulator on heat transfer surfaces. Therefore, both factors reduce heat transfer and thermal efficiency of boilers, heat exchangers, etc. The presence of any sediment in equipment such as boilers is undesirable, so its constituent elements such as calcium, magnesium, iron, and silica must be separated from the water entering the boiler.

How does sediment increase boiler fuel consumption?

As the heat transfer and thermal efficiency of the boiler decrease, heat absorption from combustion gases decreases, energy is wasted, and steam production also decreases. Therefore, to compensate for the decrease in steam production, the amount of fuel consumed by the boiler increases.

Deposits accelerate corrosion and cracking of the boiler shell

Thermal surfaces and pipes that are insulated with deposits on one side and are at the temperature of hot gases on the other side become very hot and lose their resistance. In this case, cracking of the pipes and even the boiler shell will be inevitable. Therefore, providing appropriate solutions to the aforementioned problems is of great importance. In addition, deposits can accelerate corrosion. The accumulation of deposits, corrosion products, and their accumulation cause the formation of bulges and swollen spots on the surfaces.

Problems of sediment formation in facilities:

Increased sedimentation leads to problems and dilemmas, the most important of which are the following:

• Severe reduction in system heat transfer
• Reduction in the speed and amount of water circulating in the system
• Corrosion of boilers and other heating systems
• Deterioration in the quality of produced steam
• Waste of chemicals
• Leaving stains on products, food, and textiles
• Increase in the amount of heat and energy required for cooling and heating operation
• Severe reduction in system efficiency

A solution for eliminating residual sediments in facilities

In order to eliminate residual sediments, facility operators with any type of treatment system will encounter a significant amount of sediments after a while, which they must inevitably dissolve. The remaining sediments will be removed by acid.

A variety of chemicals are used in different industries, but there are many similarities in the general method of use.

It should be noted that the best way to avoid the consequences of scale formation and avoid the costs associated with it is to prevent it. By producing anti-scale and anti-corrosion solutions, Abrizan Company has played a significant role in monitoring industrial waters and, consequently, increasing the useful life of facilities and increasing energy efficiency.