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Article: Hot Air Process Heating Oven Too Big? Save Space with IR-Air Combo

Hot Air Process Heating Oven Too Big? Save Space with IR-Air Combo

If space is at a premium in your manufacturing plant, you’re not alone. When you’re developing a new product or a new manufacturing process, chances are you’re looking for process heating equipment that takes up a minimum amount of space while meeting your quality and line speed goals.

What if we told you that you can combine infrared and hot air technologies to create a shorter length dryer without compromising throughput?  For many drying applications, these innovative designs that use a combination of IR heaters and hot air convection, can achieve the same or better results in about one-fourth the space required for a hot air dryer.

Saving space is also about saving money, and combination IR-Air ovens cost less upfront and over time as well. These combination dryers often cost considerably less than a hot air solution designed to operate at equivalent line speeds; depending on your application, you could save as much as 50% on the cost of the dryer alone. IR’s energy efficiency also means these ovens will reduce your operating costs.

Why a combination Infrared-Air oven is smaller and more efficient

In an IR-air combination dryer, a short infrared bank is added in front of a longer hot air dryer. IR can create a much more intense burst of energy in a shorter space: as much as 4 to 5 times that of a hot air oven.

In a typical hot air dryer, as much as a third to half the length of the dryer may be used simply to get the coating and the water in the coating up to a specific temperature. The rest of the length holds the coating at the desired temperature to achieve the desired drying results.

In a combination oven, the IR bank is used to quickly heat the coating up to the desired temperature. Then the hot air bank takes over and completes the drying or evaporating process. Since the coating is already up to temperature, the hot air equipment can start the drying process right away and can complete the job with up to 50% shorter length.

The benefits in productivity

By adding a short IR bank up front, typically just a few feet, you can achieve the same or better line speed with a much shorter dryer. Or, if you’re looking to increase capacity in the same amount of space, using a combination dryer can achieve that goal as well.

Here’s what combination IR-Air ovens accomplished for two Radiant Energy customers:

  • A 3-foot long IR dryer installed in front of a 50-foot hot air dryer was able to double the customer’s line speed.
  • Another customer replaced a 60-foot long hot air oven with a 10-foot combination IR-air oven to meet the production demands for a popular new product.

In both cases, the customers reaped the benefits of significant savings in space, capital equipment cost and energy consumption.

Is an IR-Air combination dryer right for you?

You may be wondering, why not just use IR alone if it’s so efficient? You can, if you have the right application. For some thin, water-based coatings, IR can be used exclusively to produce a consistent product with no skinning issues. But using IR alone is not suitable for every process heating application.

For thicker coatings, the energy can be too intense, causing a number of undesirable results: the coating can skin-over on top and be still wet underneath, or blisters can appear in the coating. Thicker coatings require longer dwell time at a lower temperature to dry gently and ensure the consistent results you need.

That doesn’t mean you’re stuck with a large, expensive hot air oven if you need to dry a thicker coating. Depending on your application, a company that’s knowledgeable and experienced with both IR and hot air can come up with the right combination of technologies to produce good results for you.

Turn to the experts for the right IR-Air combination design

There are many types of infrared heaters and they generate energy at different wavelengths. By tuning the wavelength of the energy to the best absorption wavelength of the product being heated, you get very high rates of energy transfer, making the process very efficient.

With this knowledge and experience, engineers at Radiant Energy Systems are able to design ovens using the heater that is most appropriate for a given application. The result is a system that is compact and very energy efficient.

For the right application, IR-air combination can be the perfect way to save space, save money, and increase throughput. But all vendors are not equally knowledgeable in both types of technology.

How to tell if your vendor has the experience to design the right IR-Air dryer for you

Many companies offer IR dryers or hot air dryers, and some offer equipment that uses both types of technology. But it pays to do your due diligence and look into how much expertise the company has in BOTH technologies. Here’s what to ask:

1. Have they created combination dryers both for customers in your industry and for other types of products as well? Ideally you want someone who understands your business, but also has learned lessons from clients in other industries that can be useful for your application. TIP: A vendor with a well-equipped pilot line is most likely to have this kind of broad experience.

2. Do they build all the components themselves or buy one technology from a subcontractor?If they are outsourcing the IR or the hot air component and building the other in-house, chances are they may not have the knowledge or ability to analyze your situation and combine the technologies in the most effective way for you.

3. Do they create custom designed ovens? It’s unlikely that an off-the-shelf product can meet your specific needs as well as one that’s designed for your product.

Choosing the right technology for your application is critically important to maximize the efficiency of your process. Make sure you work with a supplier with the process expertise to help you get the most from your investment.