Browse previously asked/answered questions below.
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How can I reduce my gas consumption for molten metal blanketing?
By reducing the oxygen content above the induction furnace, inert gases—typically argon—have proven benefits for blanketing molten metal, including higher yields, lower alloy fading, decreased nonmetallic inclusions, reduced casting porosity, lower casting rework and rejects, and increased refractory lifetime. However, inert gas costs can impact your bottom line.
Air Products’ patented swirl cone technology delivers all the benefits while using up to 50% less argon. In side-by-side testing, this patented technology using gaseous argon reduced the oxygen level above the furnace to less than 2%, with little or no interference to the melting operation. In addition, the technology’s design enables it to remain in place during charging and pouring.
To learn more about this technology and how it can improve the cleanliness of your coreless furnace melt, watch our short video. You can also give us a call at 800-654-4567.
Would it help to add oxygen to my cupola? If so, how should it be added?
||Russell Hewertson |
Manager of Combustion Technology
Adding oxygen to your hot or cold blast cupolas can provide many benefits, including increased production rates, reduced coke usage, alloy solids injection into the melt zone, coke replacement with natural gas and reduced afterburner loads. The simplest way to add oxygen is to enrich the blast air. Since the oxygen isn’t targeted to a particular zone, however, the benefits are typically suboptimal. Oxygen lances (subsonic and supersonic) within the tuyeres require more equipment but provide significantly better results, particularly in production rates and coke savings. Supersonic oxygen–natural gas burners, which are retrofitted into the tuyeres, allow for even greater coke savings and production increases, plus reduced alloy losses of silicon and manganese. These burners can also be used in tandem with a solids injection lance to add fine alloy particles or recycled fines directly to the melt zone.
To discuss the right solution for your operation, give us a call at 800-654-4567. Mention code 749.
I know my flowmeter tells me that I have a certain gas flow rate, but how can I be sure?
|Flowmeters must be sized properly for each particular application, type of gas, gas pressure, and operating range. First, make sure that your flowmeter is calibrated for the specific gravity of the gas that you are metering. Check the label or the glass tube of the flowmeter or call the manufacturer to be sure. Second, operate the flowmeter only at the pressure for which it was calibrated. As an example, a variable-area flowmeter calibrated for 80 psi and reading 1000 scfh will really only be delivering 760 scfh if it is operated at 40 psi. This is a 24% error! Third, for best accuracy and to allow room for adjustment, size the flowmeter so that your normal flow rate falls within 30%–70% of full scale. These three steps will help ensure that you have good control over your gas flows and, ultimately, your process. |
For a free copy of Gas Atmosphere Analysis Guidelines, please call 800-654-4567.
I use high-pressure gas cylinders and am concerned about safety. Is there a better way?
||John Tapley |
Microbulk Business Development Manager
Traditionally, high-pressure gas cylinders have been the supply mode for users in the low- to medium-volume range. This has left companies vulnerable to safety risks associated with moving cylinders and exposure to high pressure. Consolidating to a centralized microbulk system eliminates the need to handle cylinders and reduces the risk of product mix-up. Further benefits include decreased exposure to high-pressure containers and reduced traffic congestion with less frequent supplier deliveries.Air Products developed the microbulk supply option as a cost-effective, reliable alternative to high-pressure cylinders for nitrogen, argon, oxygen and carbon dioxide supply. In addition to efficient and flexible storage systems, innovative piping solutions are available to help you have a smooth transition from cylinders to microbulk.
Is it true that NFPA 86C has changed?
||Mark Lanham |
Yes, it's true. In fact, NFPA 86C no longer exists. The requirements for "Industrial Furnaces Using a Special Processing Atmosphere," formally defined in the 1999 version of NFPA 86C, have been incorporated into NFPA 86 as of July 18, 2003. Now, NFPA 86 combines the furnace safety requirements for all types of industrial furnaces, including Class A – Food and Baking Ovens, Class B – Melting Furnaces, Class C – Furnaces Using Special Processing Atmospheres, and Class D – Vacuum Furnaces.
The previous contents of NFPA 86C are now primarily found in Chapter 11 of NFPA 86. A notable change is that NFPA 86 recommends that users of Class C furnaces include a low temperature alarm panel to indicate an overdraw condition on the ambient air vaporizers used for emergency purging. Previously, NFPA 86C required the use of a low temperature flow-restricting device that could potentially limit available purging capacity. Air Products' PURIFIRE® nitrogen supply monitoring system is designed to help you comply with this new recommendation.
Users of furnaces with special processing and flammable atmospheres should fully understand the requirements and recommendations of NFPA 86 and determine how the changes from the old NFPA 86C may affect their furnace operations. For help in understanding these specifications or for more information about our PURIFIRE nitrogen supply monitoring system, contact us at 800-654-4567.
Can I remotely monitor what’s happening in my furnaces and other process equipment while I’m away from my plant?
||Chris Ward |
With the proper instrumentation and controls, you can securely monitor and control your heat treating or thermal process from nearly anywhere in the world! This is possible using a variety of hardware and communication methods, including Internet, dial-up, and cell phones. Alarm and warning notifications can also be proactively delivered to you so you can react to upsets, trends, and events before it’s “too late.” It’s important to identify the key parameters, equipment and instrumentation you want to monitor, and then select the hardware and software that best match your needs. Contact Air Products’ team of remote process monitoring and control specialists at 800-654-4567 for an assessment and recommendations as to how to get started.
How do I know if I’m wasting gas due to leaks in my gas piping?
Gas piping leaks can result from various conditions, including improper thread sealing, missed brazed joints, defective piping, over pressurization, or even vibration and shocks. A pinhole leak can cost you tens of thousands of dollars per year, depending on the size, number and severity of the leak(s). There are many ways to detect leaks; for instance, using soap tests, pressure drop tests, mass spectrometry or thermal conductivity tests. They all have their place; however, they also often come with limitations in precision, speed, difficulty or cost.
Air Products’ leak detection service can identify and repair costly leaks in your piping to help improve your part quality and bottom line.
In a short video, various methods for identifying leaks are described in more detail. You can view it online at www.airproducts.com/experts2. If you’d like to speak to a specialist about a leak detection audit of your facility, give us a call at 800-654-4567, and mention code 833.
Why do people use oxygen for combustion when air is free?
||Russell Hewertson |
Manager of Combustion Technology
Air contains almost 80% nitrogen, which doesn’t burn; it heats up and removes heat from the process as it exits in the form of hot flue gases. Combustion with oxygen eliminates this waste and provides faster melting, lower fuel usage, lower carbon dioxide generation, reduced NOx and particulate emissions and higher flame temperatures. Oxygen also efficiently burns lower quality fuels and wastes. The economics of using oxygen depend on the process and the needs of the manufacturer. Oxygen benefits are greatest for manufacturers who need extra production, have higher temperature processes (glass, steel, etc.), lack heat recovery, or have emissions issues or undersized baghouses. Oxygen is generally less attractive for just fuel savings, especially for lower temperature processes like boilers, unless fuel costs are extremely high or there are other drivers.
Can your process benefit from oxygen? Call us at 800-654-4567.
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