Leaky vacuum vessels can be diagnosed to restore capacity, eliminate thermal damage to product and improve CIP performance.

Diagnosing Leaky Vacuum Vessels

A simple leak test will determine whether a vacuum system has excessive leaks. This is highly recommended, to establish the acceptable level for good system performance.

Why is this so important? 90 percent of all evaporator performance problems are due to vacuum leaks. There’s no such thing as a small vacuum leak either, as noted above. Vacuum leaks can create a domino effect that has implications for efficiency, possible product damage and more.

Leaky Vacuum Vessels: What to Look For

If your evaporator is running hot, this is the most common symptom of a vacuum leak (or insufficient system venting).

With any vacuum leak, non-condensable gasses entering the system quickly expand to a significantly larger volume and choke the flow of gasses through the venting lines to the surface condenser, and the capability of the vacuum pumps to pull those non condensable gases out of the system. Watch our related webinar.

If you have a new piece of equipment and have the ability to shut it down overnight, do the following:

• Run the system, pull vacuum and then shut the unit down. The next day, what is the vacuum level? It is normal to lose 1/2″ mercury per hour — anything higher and you most likely have a leak.
• If you are in a quiet environment, walk around while the system is under vacuum and listen for the “hissing” sound of an air leak.

For existing equipment, it’s often not possible to shut everything down to inspect as above. Ultrasonic leak detectors are the most effective method for inspecting an entire evaporator system for possible leaks, although they do require training and some experience to use properly.

Read our previous posts on investigating vacuum leaks and vacuum control.

Vacuum Leak Monitoring

Caloris recommends a system for vacuum leak monitoring with an airflow meter on the vacuum pump discharge. All air that leaks into the system exits past the meter. The meter allows you to document normal airflow volume when the system is known to be “tight” and then routinely monitor the air flow rate to identify a deviation from the normal.

Caloris is Here to Help!

If you are experiencing lackluster evaporator performance, a review of your system will help locate leaks. Caloris can help with such evaluations, following up with recommendations for system performance improvement. Give us a call at 410-822-6900 or send email to problem.solved@caloris.com to arrange an inspection/evaluation of your equipment.