Boiler inefficiency can cost your business hundreds if not thousands of dollars each winter. Thankfully, there is one thing you can check immediately and have repaired, if needed, to help you keep your heating bills low this season.
The Number 1 Reason Your Boiler Is Inefficient
The number one reason for boiler inefficiency is refractory failure. When a refractory fails, the heat created by the combustion process is lost because the refractory is no longer able to provide the optimal amount of insulation.
Understanding Boiler Refractories
Your boiler’s refractory is essential for proper operation because it is the material that lines your boiler to help keep the heat inside the combustion chamber. It is also used to line the ash hopper and to protect the tubes in the lower furnace wall. Refractories can be comprised of brick, mortar, or aggregates mixed with a binder (ramming or gunning mixes).
Common Problems with Refractories
Since refractories help keep the heat inside your boiler so that it can heat the water for your radiators, damage to the lining can significantly reduce your boiler’s efficiency, causing it to use more fuel. If the refractory is significantly damaged, you may have to completely shut down your heating system until the refractory is repaired or replaced. Common problems with refractories include:
1. Improper Installation
According to the ASHI Reporter, refractories are designed to last between seven and 20 years. The exact lifespan depends on the type of material used to line the boiler and the installation. Improper installation can shorten the expected lifespan of the refractory, leading to cracks and holes long before they would be anticipated or expected.
2. Wrong Material Selection
Before a boiler can be lined, the temperature, type of fuel and combustion chamber environment both before and after combustion must be taken into account in order to prevent premature refractory failure. The particular material used to line the combustion chamber must be able to withstand varying pressures without cracking, high temperatures and the creation and collection of ash and slag from burning fossil fuels. If the wrong material is selected, the refractory could fail in as little as 12 months, according to an article by Insulation.org.
The fuel type itself is also important. Different fuels, including gas, heating oil and propane, have different chemical properties and different amount of moisture present within the fuel that could degrade certain refractory materials. Chemicals that should be taken into consideration include hydrocarbons, sulfur and vanadium, which can be present in the fuel and interact with the refractory material, causing a separation of the mortar and aggregate materials. It’s also important not to change the fuel type without first performing a complete analysis of the refractory and the fuel. In the same article by Insulation.org, a power company changed the fuel type for their boilers and experienced a failure within one month of the fuel change.
3. Improper Storing or Mixing of the Material
Since refractory materials are non-metallic, usually comprised of aggregates, clay and mortar, the natural materials must be properly stored. Excess water or moisture infiltration can negatively impact the durability and longevity of the product and affect drying and curing times. If the material is improperly mixed, it can lead to a refractory that may not hold up to the varying temperatures and pressures inside the combustion chamber, leading to sheering, holes and the seeming disappearance of the material.
Energy Savings with a Well-Maintained Refractory
A well-maintained refractory can result in your boiler using less fuel, which saves you money on your monthly heating bills, which means getting regular inspections and repairs to your boiler’s refractory. The inspection process starts with the collection of data on the types of materials that comprise your boiler’s refractory and potentially collecting samples so that it can be analyzed. It also involves collecting fuel samples in order to determine the exact chemicals that are present in your fuel in order to determine if they have the potential to react with your refractory, causing cracks, holes and sheering.
Next, the refractory is visually inspected to ensure it is in good condition. If damage is present, the refractory may need to be repaired or replaced, and making sure that your refractory is always in good condition can save you between 5 and 7 percent in fuel costs, according to an article posted by Columbia Edu.
To heave your boiler’s refractory inspected and repaired, call us at 800-225-2443.