Manufacturing and process industries require steam for various process operations. Therefore, boilers are imperative for generating high-quality steam to accomplish operational purposes in the processing facilities. One of the most important factors to consider before investing in a steam boiler is boiler efficiency. Boiler efficiency can be termed as the ratio of the useful heat output to the total energy input. The majority of heat lost in the steam boiler is in the boiler water or stack. The process plant can significantly increase its boiler efficiency by following some practices, consequently reducing excess costs.

 

15 Practices to Increase Boiler Efficiency:

 

 

• Regular Tuning of the Burner:

 

 

The right amount of air is one of the factors that impact boiler efficiency. A certain amount of oxygen is essential for the proper combustion of fuels. In case of air being too low, the carbon in the fuel starts to oxidize, leading to the formation of carbon monoxide. It results in the release of heat in a reduced amount as the fuel is not burned completely. Soot, smoke, and carbon monoxide are caused due to low air that causes harm to the boiler. Excess air also decreases boiler efficiency as it is transported to the stack hot that wastes heat.

 

An optimum amount of air ensures proper and complete combustion of the fuel. For proper combustion, the amount of air needs to be measured with an O2 probe. The probe is inserted in the stack while tuning the burner for optimal boiler efficiency. Tuning the burners regularly results in maximum savings of fuel.

 

 

• Reduce the Stack Temperature:

 

 

Reducing stack temperature is an easy process that decreases the operating pressure when the steam boiler is not in operation.

 

 

• Proper Insulation of Valves:

 

 

Insulation plays a crucial role in capturing heat and preventing its wastage. Neglecting the insulation after maintenance can cause tremendous heat loss. Insulating valves helps in avoiding heat loss, reducing accidents, and ensuring easy access for maintenance. Optimal use of heat, in turn, increases the boiler efficiency.

 

 

• Using an Economizer:

 

 

Economizers utilize the wasted hot flue gas and heat the feed water for combustion purposes in a steam boiler. Installing an economizer can significantly reduce the fuel consumption for heating the water, thereby increasing the boiler efficiency.

 

 

• Cleaning of Fireside:

 

 

As the boiler age advances, the soot layers start forming on the fireside of the boiler tubes that act as an insulator. Consequently, it reduces the heat transfer rate and increases fuel usage. Due to the low heat transfer rate, the hot gases pass without transmitting heat to the water. It resultantly increases the stack temperature and decreases the overall boiler efficiency. Therefore, it is necessary to inspect and clean the fireside of the steam boiler to prevent soot formation.

 

 

• Cleaning of Waterside:

 

 

It is pivotal to thoroughly check the waterside to ensure that there are no leakages or scale formation. Scaling forms on the heat transfer surfaces due to improper chemical treatment, high levels of water hardness, and irregular blowdown. It results in hindering the heat transfer that eventually reducing the boiler efficiency. If overlooked, scaling can cause overheating in boilers that lead to expensive boiler repairs.

 

 

• Boiler Blowdown:

 

 

Boiler efficiency can be increased by recovering heat from the blowdown process. The blowdown valve helps in releasing the boiler water containing soluble and insoluble solids. It reduces the number of dissolved solids that impede the heat transfer process.

 

 

• Controlling Blowdown Rate:

 

 

Although blowdown removes the impurities from the steam boiler, it also discharges heat from the boiler system. It is crucial to maintain the rate of heat drained through blowdown. The required amount of blowdown can be ensured by installing an automatic blowdown valve.

 

 

• Return Condensate to the Boiler:

 

 

Condensate is the result of steam transmitting its heat and condensing. The by-product is utilized with already heated water that requires less fuel to generate steam again. Reusing the condensate also reduces the amount of makeup water and chemical treatment required. 

 

 

• Preheating Combustion Air:

 

 

If the air feed in the boiler for combustion is already heated, it requires less fuel to generate steam. A 40 °F increase in the air used for combustion can save up to 1% fuel costs.

 

 

• Retrofitting Burners:

 

 

Steam boilers require air for proper and complete combustion. Too little air or too much air affects the combustion process, thereby reducing the overall boiler efficiency. Retrofitting and upgrading to a high-efficiency burner is a better option compared to tuning the burners. Retrofitting is an ideal solution for burners that are more than 15 years old. Burner upgrading can save up to 20% of fuel costs.

 

 

• Reduce Carryover:

 

 

Carryover is caused by water leaving the boiler system along with steam. The wet steam carries impurities like dissolved solids with it. The impurities leave deposits in the boiler system that impacts boiler parts such as control valves and pressure regulators. It results in damage in steam boilers that affects their efficiency.

 

 

• Inspection of Steam Trap:

 

 

A broken or damaged steam trap allows steam to blow away into the condensate system. Therefore, it is important to regularly inspect the steam trap and replace it if broken to ensure maximum efficiency.

 

 

• Avoid Excessive Use of Steam:

 

 

Reducing steam usage can significantly increase boiler efficiency. Insulating the pipes and tanks heated by steam decreases steam utilization and consequently fuel usage. A high-pressure condensate system can reduce the steam used at the deaerator and fuel requirement in the boiler. 

 

 

• Regular Maintenance of Boiler:

 

 

Despite following precaution and standard guidelines in operating steam boiler systems, issues like corrosion, scaling, foaming, etc., are inevitable in the boiler system. It is vital to conduct boiler maintenance regularly to obtain peak efficiency.

 

Rakhoh Boilers is a leading name in industrial steam boiler manufacturer and thermal solutions since 1983. We have successfully installed 3000+ boilers in 26 countries worldwide for over 20 process industries. We manufacture robust steam boilers and provide the best boiler services to enhance boiler efficiency and productivity.

To learn more about our products and services, visit www.rakhoh.com