5 Maintenance Tips for Gas Catalytic IR Ovens

I’m an infrared (IR) subject matter expert, a techie and enthusiast. This means I have the privilege of living real life episodes of “How It’s Made” including projects such as those where I manage advanced exothermic reactions (I’ve always wanted to use that term in an article) as well as heating requirements for aerospace coating. That’s not all — ever wonder how that cool military grade composite or high-definition thermoforming of high-end spa is made? One of my personal favorites is the custom paint shop that oozes masterful talent in its craft. Part of my being on-site with these industrial gurus usually involves providing them with hands-on equipment training, troubleshooting their infrared heating equipment or a combination of both.

From my observations of our highly competitive, fast-paced, “get it done” industrial realm, production equipment is sometimes pushed beyond its limits. Keeping up with a proactive, preventive maintenance schedule and carrying a few spare parts drastically reduces the chances of unexpected downtime. Regardless, we become “Scrooges” by poorly maintaining our machinery; for months, we thumb our noses at the constantly screaky conveyor sprocket with its sad little pile of metal shavings or ignore the deafening drive belt noise.

Unfortunately, the scary truth of the matter is that it hits us when our facility’s revenue-generating production line is brought to a screeching halt. “The Ghost of Maintenance Past” (or lack thereof) finally rears its ugly head.

It’s at this very moment when we begin realizing the harsh reality and consequences of our neglectful actions.

Truth be told, most process interruptions involving gas catalytic ovens often boil down to the lack of maintenance, not the personnel themselves. It got me thinking, “Why is that?” Maybe it’s because other than a relatively unassuming exhaust fan, gas catalytic IR ovens produce little sound. Come to think of it, they don’t create bright light or even emit odors while in operation, either. Without these common mechanical sensory triggers, our brains simply go into, “If it’s not broke, don’t fix it,” mode.

Fear not. I’m not here to point fingers or lay blame. I’m here to help, like a jolly (and somewhat sarcastic) “Ghost of Maintenance Future.” For those interested in changing their ways toward safeguarding unwarranted abuse of these industrial heating wonders, here are five simple steps to help industrial oven owners stay in good spirits.

1. Basics: Set yourself up for success

When first commissioning the oven, create a heater panel comparison chart by operating it for about 20 minutes at its maximum output. Obtain average heater panel temperature readings and note them. Doing so will provide future reference information concerning notable process variances that may occur.

2. Basic Oven PM: Keep it clean

Reflectivity is a key factor to maintaining the performance of a gas IR oven. Keep overspray or powder drift buildup on the interior walls to a minimum. Enabling material to bond to the interior walls will result in lowering reflected energy, adversely affecting part coverage and reducing oven output.

This is due to the infrared being absorbed instead of freely reflecting throughout the inner curing space.

Do not use compressed air to blow off heater panels; the catalyst media will be damaged. Do not vacuum the heater panels; the catalyst media will be damaged.

3. Monthly PM: Check gas pressures

Catalytic IR systems normally require lower incoming fuel pressures than their convection counterparts. Low operational pressures are measured by inches of water column. As a reference, 1 inch of water column is equal to approximately 1/28 of a psi. In most cases, fuel gas is controlled by a combination of the valve train and electric or mechanical regulators. Manufacturer designs and controls will vary.

4. Six-month PM: Simple checkups

Inspect exhaust fan belts and drives. Faulty exhaust operation can lead to poor oven performance, dangerous levels of process fumes and harmful smoke in the workplace. Check for gas leaks at fittings and unions.

5. Replace heater panels in pairs

Because their output will be higher in comparison to those in the same area of the oven, replace new or refurbished heater panels in opposing left and right sets. This will help alleviate inadvertent hot spots in an oven.

Pertaining to proper testing of both liquid and powder applications: When an IR system is in use, following these simple steps will help ensure accurate

temperature readings. Unlike convection ovens which force heated air over a part’s surface, gas catalytic IR ovens produce directed energy that targets the applied finish, not the substrate. For the first step, the piece should initially be cured and cooled. Next, securely attach contact thermocouples at key surface points. Finally, run said part through the oven. Note entry and exit times to help correlate temperatures to results gained.

Do yourself a favor, implement these four, cost-effective measures to ensure your gas IR oven stays happy and produces quality results, day after day, for years to come.