Carryover in boiler is a serious problem that can reduce system efficiency, increase operating costs, and even damage equipment. Carryover occurs when boiler water is carried over into the steam, which can then cause deposits on turbines, corrosion on pipes, and disruption to production processes that rely on pure steam.

The most common form of carryover is the carrying over of boiler water droplets containing dissolved and suspended solids.

Causes of Carryover

Carryover can be caused by a variety of factors which are generally categorized into two: mechanical and chemical.

Mechanical Causes

Boiler Design: Suboptimal boiler design can increase the risk of carryover. Factors such as design pressure, steam drum size, circulation rate, and the type of mechanical separation equipment used affect the purity of the steam produced.
High Water Level: Too high a water level in the boiler can cause water to be carried away with the steam, especially if there is no effective separation mechanism.
Combustion Method and Load Characteristics: Improper combustion methods and sudden load fluctuations or operations above design capacity can increase the potential for carryover.

Chemical Causes

High Solids Concentration: High concentrations of dissolved or suspended solids in boiler water can lead to the formation of stable foam, which is then carried away with the steam.
Excessive Alkalinity: High alkalinity levels can increase the tendency for foam formation, which contributes to carryover.
Contamination by Oil or Other Organic Materials: Contaminants such as oil or other organic materials can react with the alkalinity of the boiler water, forming compounds that cause foaming and carryover.

Negative Impact of Carryover

Carryover in boilers is not just a technical problem, but also has a major impact on the operation and efficiency of the system as a whole. Therefore, understanding the impact of carryover is essential to maintain optimal performance of the boiler system and prevent unwanted operational disruptions.

1. Deposit Formation

Solids entrained with steam can deposit on valves, heat exchangers, turbines, and superheaters, reducing heat transfer efficiency and turbine performance. Accumulation of these deposits can accelerate equipment degradation, increase the need for periodic cleaning, and potentially cause unplanned shutdowns.

2. Erosion and Corrosion

Contaminants in steam can cause erosion and corrosion of steam system components, reducing equipment life and increasing maintenance costs. Corrosion can occur due to chemical reactions between contaminated steam and pipe and equipment materials which can eventually lead to leaks or even structural failure.

3. Decrease in Product Quality

In processes that use steam directly, carryover can cause product contamination, affecting the quality and safety of the final product. For example, in the food and pharmaceutical industries, contaminated steam can change the chemical composition of the product and pose a health risk to consumers.

4. Decreased Energy Efficiency

The wet steam produced by carryover has a lower heat content than dry steam, reducing the overall efficiency of the system. This requires the use of more fuel to produce the same energy, significantly increasing operating costs.

5. Increase the Risk of Equipment Failure

Accumulation of deposits and corrosion due to carryover can cause blockage or even failure of piping systems and other critical equipment. This risk is even higher if carryover is not immediately addressed with appropriate control strategies.

6. Higher Operating Costs

Carryovers that are not handled properly will require increased maintenance and repairs, which ultimately increases operating costs. In addition, downtime due to equipment repairs and replacements can disrupt productivity and reduce business profits.

Strategy to Overcome Carryover

Addressing carryover requires a comprehensive approach, from boiler water maintenance to optimal operation management. Here are some solutions that can be implemented:

1. Improve the Quality of Feed Water

Use pre-treatment systems such as softeners, reverse osmosis, or demineralization to reduce the levels of dissolved substances in the feed water. Ensure that the pH and alkalinity of the water are within the appropriate range to avoid excessive foaming.

2. Control of Solids Concentration in Boilers

Perform regular blowdowns to remove excess solids from the boiler. Use an automatic control system to monitor and regulate the total dissolved solids (TDS) concentration in the boiler water.

3. Optimize Boiler Design and Operation

Ensure the boiler design allows for effective separation of water and steam. Avoid drastic load changes to maintain stable boiler operation.

4. Use the Right Chemical Treatment

Apply antifoaming agent to reduce foam formation that causes carryover. Use pH controller and dispersant so that solids are not easily carried away in the steam. Make sure the dosage and type of chemical used are in accordance with the conditions of the boiler system.

5. Routine Monitoring and Maintenance

Conduct regular water quality analysis to ensure that boiler water parameters are within optimal limits. Use professional monitoring and maintenance services to prevent and effectively handle carryover problems.

Trust Your Boiler Solution to Lautan Air Indonesia

Boiler carryover is a problem that cannot be ignored because it can have a major impact on operational efficiency and sustainability. However, with the right approach, this problem can be effectively addressed.

Lautan Air Indonesia provides a complete solution for boiler maintenance, including:

Water Treatment Chemicals to control boiler water quality and prevent carryover.
Operation & Maintenance Services to ensure your boiler is operating optimally.
Boiler Water Treatment Consultation to help you find the best strategy for boiler water management.

Don’t let carryover hamper your productivity and increase your operating costs! Contact Lautan Air Indonesia now and get the best solution for your boiler system.

How to Overcome Carryover in Boilers?