The best way to avoid particulate fouling is to keep the cooling water clean and thereby prevent particles from entering the heat exchanger. However, in all cooling systems, and especially when using open cooling systems (with cooling towers), there will always be particles present in the cooling water.

The deposition of any undesired material on heat transfer surfaces is called fouling. Fouling increases the overall thermal resistance and lowers the overall heat transfer coefficient of heat exchangers. Fouling also impedes fluid flow, accelerates corrosion and increases pressure drop across heat exchangers.

The buildup of fouling also reduces the cross-sectional area of the tubes or flow channels and increases the resistance of the fluid passing over the surface. These side effects combine to increase the pressure drop across the heat exchanger, reducing flow rates and aggravating the problem further.

once per year

Unfortunately, heat exchangers cannot be repaired. When a heat exchanger cracks or rusts through it must be replaced. Because the heat exchanger is at the center of the furnace, nearly the whole furnace must be disassembled. Even if the parts are covered under warranty, the labor and freight will start around $500.

The cost of replacing a heat exchanger ranges from $2,000 to $3,500. Replacing your furnace’s heat exchanger would be a good route to take if your furnace is fairly new. However, it is not worth spending your money on replacing your heat exchanger when it is near the end of its life span, which is ten years or more.

Scalzo is the most effective product for cleaning heat exchangers, although some require special products. Scalzo contains hydrochloric acid for the most effective cleaning, plus corrosion inhibitors and dispersants to ensure the metal is protected and post-cleaning fouling does not occur.

If so, here’s the thing: replacing a heat exchanger isn’t as simple or affordable as it sounds. In fact, replacing a furnace heat exchanger can take up to 8 hours and can cost anywhere from $2,000 to $3,500.

Internal tube cleaning of soft deposits like dust, algae, mold, can be accomplished by utilizing brushes called molded plastic cleaners (PIGS). Brushes are also typically used in cleaning of tubes with enhanced surfaces for better heat transfer like twisted tubes, spirally indented tubes, or finned surfaces.

The furnace heat exchanger The combustion chamber is the center barrel. The surrounding square section is the heat exchanger. Oil furnace heat exchangers are subject to soot buildup. Soot is deposited on the sides of the heat exchanger and insulates the heat exchanger causing less heat transfer.

Drop the nozzle into the container filled with kerosene. The nozzle itself will need to set for about a half an hour to make sure to get all of the soot and debris off of it. Once you have taken the nozzle out of the kerosene get out your rag and wipe it clean.

Dirty furnace coils are not as good at transferring heat energy, and you’ll start to see your system’s energy-efficiency dip. In severe cases, extremely dirty coils can trap heat inside your furnace, causing the system to overheat and trigging temperature failsafes that shut off the system entirely.

every three months

The most common symptoms are the following:

1. Increased pressure drop from inlet to outlet.
2. Loss of heat transfer efficiency.
3. Loss of flow and performance.
4. Process fluid leakage.

When the boiler is on, the burner flame should be steady and blue in colour. If the flame is yellow and is moving around a lot, then this could either be a sign that the burner is dirty or that the heat exchanger has a crack.

If you have a furnace that is considered high-efficiency (90%+ efficient), it contains both a primary and secondary heat exchanger. As the combustion exhaust leaves the primary heat exchanger, it travels into a secondary heat exchanger where more heat is released from the flue gas and water vapor begins to form.