How To Troubleshoot Your Plate Heat Exchanger

We’ve all been there — you get into the plant one day and things aren’t going as planned. Sometimes, it’s a small puddle by your heat exchanger. Other times, it’s a drop in outlet pressure. Whatever it is, you know it will take some troubleshooting (and possibly a call to a service tech) to get fixed.

We’re here to remove some of the hassle for those days when things just aren’t going as planned. So let’s dive into the top four problems you may face operating your plate heat exchanger, why they’re probably happening, and how to fix them.

There’s Leaking Outside the Unit

Great — a puddle outside your plate heat exchanger. So, what does it mean?

Why it’s happening

Leaking outside of your unit is usually brought on by one of these common causes:

• Worn or damaged gaskets
• Warped or eroded frames
• Excessive pressure
• Improper plate pack tightening

How to fix it

While usually not an emergency, a leak in your equipment is a sign of something going on that you can’t see without opening your plate heat exchanger. Call your service tech for a diagnosis sooner rather than later to figure out the cause and fix it.

Your Product Is Experiencing Cross-Contamination

No one wants to be dealing with product quality issues — so, how can you tell if your plate heat exchanger is contributing to this issue?

Media foaming, color, bacteria contamination, or clarity changes are a surefire red flag that a leak is allowing fluids to mix. 

Why it’s happening

Cross-contamination is often caused by one of the following issues:

• Fatigued or corroded plates — Over time, cracking, pitting, or thinning of the metal plates themselves creates openings that allow fluid bypass.
• Excess pressure — Extreme pressure beyond the exchanger’s design rating can damage gaskets and plates, leading to leaks between sides.
• Thermal shocking — Sudden temperature changes in one fluid can damage plates or gaskets and create bypass routes.
• Improper assembly — If plates are aligned incorrectly during reassembly after cleaning, leakage can occur between fluid channels.

How to fix it

No matter the cause, you will want to bring in experts to perform a dye test and identify the exact point of the leak.

If you’re thinking about a helium test, you’re better off saving your plant some time (and money) and skipping straight to a dye test. While a helium test will tell you if there’s a leak, it won’t tell you where or how many leaks you have. And at the end of the day, you’ll still have to open your frame to inspect your plates — only without a dye pattern to follow, you’ll risk missing something.

AGC’s PlateCheck Service, on the other hand, will detect even the slightest hairline fracture in your plate or gap in your gasket seals and get you back up and running without a doubt that you missed something.

You’re Experiencing Persistent Pressure Drops

Experiencing some erratic swings or drops in inlet and outlet pressures? Sounds like you have some potential flow restrictions.

Internal fouling buildup is the most likely culprit if your inlet and outlet pressures are different or fluctuating, and a spike in pump power needed to maintain pressure hints at internal clogging issues.

Why it’s happening

Sudden and persistent pressure drops are often caused by:

• Fouling — When a product has a chance to build up on your plates, the product trying to move through your equipment can’t move as efficiently as your heat exchanger is designed to push it through.
• Your Cleaning In Place (CIP) process might require optimization.
• A new recipe — Any changes to your ingredients will result in a different product consistency. (Even substituting an ingredient for a nearly identical product can cause pressure drops in your equipment.) Don’t forget to run your product through rheology no so that you can configure your plate heat exchanger properly for your product.

How to fix it

If you are experiencing premature fouling, it’s best to have a tech check your CIP process to make sure that it’s effectively cleaning your plate heat exchanger. They’ll be able to open your frame, inspect the plates, diagnose the issue, and give you the next steps that won’t leave you guessing about the cause of your pressure issues.

If you recently changed anything about your product, verify your equipment is properly configured or contact AGC to run your product through rheology.

If Your Gut Tells You Something Is Wrong, Trust It

If something isn’t working correctly with your plate heat exchanger, it’s best to address it now versus down the road when the problem has only gotten worse.

Not only do our techs have in-depth knowledge and hands-on experience working with plate heat exchangers, but they also want to help you better understand your equipment so you can better diagnose any issues in the future.

Our PHE 101 course gives an overview of how to increase your plate heat exchanger’s lifespan and make day-to-day maintenance easier at your plant. We recommend it for anyone looking to improve their response to PHE issues or better understand this vital piece of equipment.