Make it or break it: Tips on how to keep your heat exchanger running smoothly
'A little goes a long way’
Author: Jamie Zachary
Modern industrial operations place a demanding toll on process equipment – and your moving bed heat exchanger (MBHE) is no exception. Extreme temperatures, abrasive materials, corrosive substances, high pressures and wear and tear are just a few of the factors that will regularly test your equipment at the all-important heating and cooling stage.
Your task is to strike a balance between efficiency and resilience, ensuring the endurance and optimal performance of your process equipment over the long term.
In the case of MBHEs tasked with heating and cooling bulk solids, a little can go a long way. Simple tasks such as cleaning the interior heat transfer surfaces (e.g., plates) and controlling the water quality can minimize longer-term issues such as fouling, corrosion and, in extreme cases, equipment failure.
Caio Raineri, Global Services and Support Manager for Solex Thermal Science, shares some additional tips below specific to keeping your plate-based MBHE for bulk solids in tip-top shape.
Regularly inspect hoses to avoid leaking, which can lead to corrosion if left unchecked.
Regularly inspect the door gaskets and nozzle seal assemblies. Over time, both can dry out and lose their ability to seal properly, leading to product leakage and/or introduction of air into the unit.
Ditto with hoses! Improperly maintained hoses can lead to fluid leaking on the threaded connections, corrosion and, ultimately, failure.
Raineri also reinforces the importance of properly maintaining the heat exchanger plates. They are in constant contact with the product as it flows between the channels and will begin to wear over time. This is particularly applicable in aggressive environments where the product is abrasive, foreign material is introduced in the product stream, the quality of the heat transfer fluid is compromised and/or other process conditions change.
To avoid plate failure that can lead to leaking, product caking, ineffective unit performance and, in a worst-case scenario, accelerated wear of adjacent plates, Raineri urges operators to perform regular inspections and preventative maintenance. If operators notice curved deformations, striations or areas of a plate that look ‘over polished,’ talk to your equipment provider. This might require further diagnosis, repair or replacement.
In many cases, it is beneficial to have spare parts on hand to swiftly address unexpected issues, minimizing downtime and ensuring continuity of operations. Depending on the makeup of your MBHE, this includes vibratory motors, seal skirts, gaskets, hoses and various moving parts on the discharge device. In the case of critical spares, the old phrase, "an ounce of prevention is worth a pound of cure" certainly applies!
In some cases, you might want to repurpose or retrofit your MBHEs – perhaps because the feed rate or physical characteristics of the product that the unit was designed for has changed or you want to use it on a different line. In other cases, you might want to relocate the equipment to another facility for a similar application.
Similarly, Raineri sometimes hears from oilseeds processors who are looking to convert an oilseeds heater into a dryer, which involves adding components such as air sections and exhaust plenums. Other examples include customers looking to add dry air injection into an older unit to mitigate condensation when capacity increases are needed; and adding or retrofitting the inlet hopper by adding a lump screen to mitigate the risk of product from accumulating on top of the plates.
Whether repurposing or retrofitting your MBHE, Raineri recommends running a process engineering sensitivity analysis of the existing equipment considering new process conditions. This will help determine the path forward by indicating whether you need to adjust parameters on the fluid side, air injection, or addition of heat exchange banks.
He also notes that operating outside of the feed rate design range (greater or less than) can impact the effectiveness of your MBHE. Within limits, this can be managed in multiple ways, ranging from reducing the water temperature and dew point of the air to adding new banks.
Do you have additional questions about how to service your heat exchanger? Or do you need to order spare/replacement parts? The Solex Service & Support department is here to help maximize operational availability and reduce your operating and maintenance costs.
Contact a member of our team today!
This entry was last updated on 2024-2-7
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