Industrial gasketed plate heat exchangers are widely used in many industries for various purposes. An underperforming, blocked heat exchanger could be the result of several factors.
The most common reason for an underperforming PHE is the unit becoming blocked, which could wreak havoc on your production line or other industrial processes.
Troubleshooting a blocked plate heat exchanger can be tricky, but with this guide, you will know exactly what to look for and how to fix the issue quickly.
What is a Plate Heat Exchanger, and How Does It Work?
Gasketed heat exchangers are essential equipment in many crucial industrial processes, so it is vital to keep them running smoothly.
A PHE is used to transfer heat between two fluids. The fluids pass through separate plates, which are then in close contact. This allows the heat to be transferred efficiently between the two fluids.
Note: In our experience, we’ve found that brazed plate heat exchangers (BPHE) offer several advantages over their gasketed counterparts. For instance, brazed plate heat exchangers are remarkably efficient with heat transfer due to their high thermal conductivity, more compact and lightweight, and higher resistance to pressure and temperature extremes. Additionally, maintenance is generally more straightforward because no gaskets require replacement. However, the critical factor that makes them a standout choice is their longevity – these devices are brazed together, essentially eliminating the risk of leaks, which are a common issue with gasketed designs. If you’re interested in exploring the benefits of these systems further, we recommend checking out the selection of SWEP brazed heat exchangers on offer. These units perfectly illustrate the potential advantages of this technology.
While PHEs are highly effective, they can become blocked if not maintained properly. When this happens, it can cause a decrease in efficiency or even a complete shutdown of the unit.
What are Blocked Plate Heat Exchanger Symptoms?
Knowing the signs of a blocked gasketed heat exchanger is the first step in troubleshooting the issue and possibly avoiding problems and costly repairs. Know more about the principles of PHE servicing.
By understanding the signs that your system is not performing as it should, you can take steps to prevent further damage and keep your production line running smoothly.
When troubleshooting a blocked plate heat exchanger, it’s crucial to inspect the plate heat exchanger plates for any signs of damage or debris that might be causing the obstruction.
The Most Common Symptoms of a Blocked Plate Heat Exchanger Include the following;
- Decreased heat transfer efficiency
- The increased pressure drop from the inlet to the outlet resulted in a loss of flow and performance.
- Fluid leakage
- Strange noises coming from the system
- An Increased temperature difference between the hot and cold fluids
If you notice any of these symptoms within your system, it is important to take action immediately.
A blocked PHE can quickly lead to more serious problems.
Why Do Gaskteted Heat Exchangers Become Blocked?
So now you know what to look out for, but what causes a PHE to become blocked in the first place so that you can avoid the same problem in the future?
What Are the Common Problems in Gasketed Heat Exchangers?
- Gasket failure – If the gaskets that seal the plate heat exchanger plates fail, it can allow for fluids to mix, which can cause a blockage. Replacing them with new gaskets will solve this problem!
- Plate corrosion – Over time, the plates can become corroded, which can cause them to swell and block the flow of fluids.
- Fouling – If the fluids are not clean, they can deposit harmful residues on the plates, blocking the flow of fluids.
If left unchecked, a blockage can cause severe damage to the unit and lead to costly repairs and disruption to your process. Read more about how to keep plate exchangers running at their best.
Four Tips to Help Prevent a Blocked Plate Heat Exchanger
There are a few things that you can do to help prevent your gasketed heat exchanger from becoming blocked.
- Ensure that you use the correct fluid type. For example, use corrosion-resistant plates if you use a corrosive fluid.
- Keep the plates clean by regularly cleaning and inspecting them. If you notice any deposits on the plates, clean them off as soon as possible.
- Avoid using too high of pressure. This can damage the plates and gaskets and lead to the mixing of fluids in the system.
- If you are not using the heat exchanger for an extended period, clean it and store it in a dry, protected area.
What to Do With a Blocked Plate Heat Exchanger?
Cleaning a plate heat exchanger
The first step is to clean your heat exchanger. Stripping down the PHE and giving all the parts a good clean is the best way to remove any build-up causing a blockage and determine if there is any damage.
While the heat exchanger is stripped down, you can assess the plates and gaskets for any signs of wear and tear.
If there is significant damage, you might need to replace some or all of the plates and gaskets.
If you are uncomfortable doing this yourself, consult with a professional (like ourselves) to help clean a plate heat exchanger.
Cleaning an Underperforming Heat Exchanger Could Involve;
- Acid cleaning
- Power flush
- Chemical cleaning
- Cleaning the inlet and outlet flow pipe
Steps to Take to Clean Your Heat Exchanger
- Shut down the system and release all pressure.
- Disconnect the heat exchanger from the system.
- Remove the plates from the plate pack.
- Clean the plates
- Reassemble the heat exchanger and reconnect it to the system.
- Start up the system and check for leaks.
What Cleaning Chemicals Are Used?
A few different chemicals can be used to clean and flush the sludge from a blocked heat exchanger.
The most common chemicals used are;
- Acids – Hydrochloric acid, sulfuric acid, and phosphoric acid effectively remove debris and buildup.
- Alkalis – Sodium hydroxide and potassium hydroxide can also be used.
- Chelating agents – These are used to remove metals from the surface of the plates.
- The most common chelating agent is EDTA.
Cleaning your heat exchanger is a simple and effective way to troubleshoot symptoms.
Replace Faulty Gaskets
Worn or damaged gaskets are one of the most common causes of why a gasketed plate exchanger becomes blocked.
If a gasket fails, it is easy to spot. Fluid drips out of the PHE because the pressure forces it through the leak.
To fix your PHE, you will need to disassemble it.
Take out the plate with the failed gasket and another plate next to it (so the flow pattern is not disrupted).
Next, if you have replacement parts available, swap them out, reassemble your PHE according to the specifications, and put it back into service.
- Gaskets should be routinely replaced every 1-2 years to ensure they are in good condition.
- Gasket failure is one of the most common causes of failure.
- If your gaskets are damaged, replacing them as soon as possible is important.
- Failing to do so can result in expensive repairs down the line.
- You’ll need new replacement parts from a supplier (like ourselves) to replace your gaskets.
- Once you have the new gaskets, remove the old ones and clean the mating surfaces.
- Install the new gaskets according to the manufacturer’s instructions.
Why Replace Gaskets in a Plate Heat Exchanger?
- Gaskets can be replaced relatively easily, which is a job most professional PHE specialists can do.
- Replacing the gaskets usually makes more sense and will help ensure your PHE runs efficiently.
How Can WCR UK Help With a Blocked Plate Heat Exchanger?
WCR UK specialises in gasketed heat exchangers and can help with all your blocked PHE problems.
We have a wide range of replacement parts and cleaning and repair services for all major brands of heat exchangers.
- Material selection and test
- Parts replacement
- Reconditioning
- Visual conditioning
- Assessment
- Condition audit
In Summary
- Fouling or gasket failure is the most common reason for failure.
- If you’re experiencing issues, the first job is to clean your heat exchanger.
- While cleaning, check the plates, gaskets, and pipework for blockages (this could be a one-time problem).
