(from Furnaces North America 2014
This presentation shows how cycle time and thermal uniformity can be significantly improved using INEX radiant tubes. Employing the superior capability of Si-SiC composites for high service temperature to 2450°F (1340°C), twice (2X) the heat flux of any metal-alloy tube is comfortably achieved. Reducing furnace ramp-up time dramatically increases productivity and throughput by 25% or more with no detrimental effect on metallurgical properties, as proven by years of actual heat treating operations. The financial benefit is quantified showing how up to $500,000 additional profit per year is attainable for every ton of load capacity.
(from Heat Treating Progress
In this article Mike Kasprzyk discusses Composite Radiant Tubes originally introduced to avoid downtime and eliminate the labor and material costs associated with metal tube replacement. More recently, with the introduction of Composite U-tubes, furnace operators have also discovered that significant productivity gains are routinely achieved. Specific case studies demonstrate how the higher heat fluxes achieved with Si-SiC composite tubes reduce cycle times and increase throughput
(from MTI Magazine
Composite tubes are capable of delivering more energy to the load (i.e. doing more work). How is this possible? By increasing the radiant tube temperature without any fear of shortening its life. How do you raise the tube temperature? Simply by firing harder and putting in more energy to get more work through the furnace.
This academic paper describes gaseous fluid flow differences using INEX Internally-Finned and Straight-Wall radiant tubes. Heat transfer factors are also discussed and compared for INEX tubes with a rough-sand surface versus theoretically smooth tube surfaces.
INEX Inc. pioneered affordable advanced materials technology to improve heat-treat operations all over the world. The superior performance and long life achieved with our patented composite Si-SiC material earns us the reputation as the "Innovators in Radiant Tube Technology"
Our revolutionary Internally-Finned tubes not only deliver the same long life and superior heat transfer capability, they literally pay for themselves. By simultaneously stirring the gas flame and increasing the inside surface area to capture more heat, these finned tubes reduce fuel consumption by approximately 10%.
Metal alloy tubes are typically designed to radiate at 55 BTU/hr/in2 (25 KW/m2), but INEX tubes excel at much higher temperatures to 2450°F (1340°C) providing twice the heat flux output of 110 BTU/hr/in2 (50 KW/m2). Because INEX tubes can be fired so much hotter, they provide faster furnace recovery, reduced cycle times and tighter temperature control. With this in mind, you can consider a smaller INEX composite tube to replace a larger metal tube for both increased performance and overall purchase savings.