Oxidizers and Heat Exchangers: Improving the bottom line

A number of systems utilize heat exchangers. Their most common application is to preheat the incoming waste gas stream. By preheating the solvent-laden air before it enters the oxidizer the burner(s) do not need to generate as many BTU's to achieve the combustion chamber set point. This reduces utility consumption.

For Example:

Increasing the inlet temperature by 100F on a 100,000CFM oxidizer that's operating online for 120 hours a week will reduce its annual consumption by over 3,300MCF of gas a year. This assumes the RTO is operating at 95% thermal efficiency, which is the standard for a new system. The annual savings would exceed $18,750 using today's gas prices.

Over time thermal efficiency decreases due to various factors (plugging, media degradation, etc...). It can begin happening a few months after commissioning, and it is ubiquitous. There are thousands of systems currently operating with thermal efficiencies below 90%. For this reason it is good to use a range of values that better reflect real-world scenarios.

By only changing the system's themal efficiency to 90%, the amount of gas savings realized will now exceed 6,700MCF annually. At today's prices this would be an annual savings of over $27,500.

Heat exchangers can be a great tool to improve the bottom line.