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Thursday, January 29, 2015

#205 - What is iEAF?

In Post #194, we asked the question - What is iBOF? In this post we will discuss iEAF.

To begin, it will be helpful to describe EAF. The acronym stands for Electric Arc Furnace and is used to describe a method of steelmaking that heats the charged material using a powerful electric arc originating from large graphite electrodes.

From Wikipedia: 
An electric arc furnace used for steelmaking consists of a refractory-lined vessel, usually water-cooled in larger sizes, covered with a retractable roof, and through which one or more graphite electrodes enter the furnace. The furnace is primarily split into three sections:
  • the shell, which consists of the sidewalls and lower steel "bowl";
  • the hearth, which consists of the refractory that lines the lower bowl;
  • the roof, which may be refractory-lined or water-cooled, and can be shaped as a section of a sphere, or as a frustum (conical section). The roof also supports the refractory delta in its centre, through which one or more graphite electrodes enter.
The hearth may be hemispherical in shape, or in an eccentric bottom tapping furnace, the hearth has the shape of a halved egg. In modern meltshops, the furnace is often raised off the ground floor, so that ladles and slag pots can easily be maneuvered under either end of the furnace. Separate from the furnace structure is the electrode support and electrical system, and the tilting platform on which the furnace rests. Two configurations are possible: the electrode supports and the roof tilt with the furnace, or are fixed to the raised platform.



iEAF stands for “intelligent Electric Arc Furnace” and is a trademark of Tenova Goodfellow Inc. The iEAF system is a progressive, modular technology package designed to provide sustainable long-term cost savings to steelmakers. The system uses dynamic control and holistic optimization of the EAF process.

iEAF® enabling technology can be applied to all variations of the EAF process including: 
  • top charge melting furnaces (bucket and/or shaft) using scrap, DRI and/or pig iron;
  • the Consteel® process (iConsteel®) with or without hot metal;
  • continuous DRI fed furnaces (iDRI®).


While the basic structure remains constant, the automation hardware, software and communication modules can be customized according to the individual customer’s existing automation system and network.

The iEAF technology package is comprised of well-defined modules which each focus on a specific aspect of the EAF process. 
  • MODULE 1 - Dynamic Chemical Energy Control & Optimization (EFSOP)
  • MODULE 2 - Dynamic Melting Control
  • MODULE 3 - Dynamic End-Point Control




While the iEAF® can be easily integrated with any existing automation and process control system, the cornerstone and necessary first step in the iEAF® technology program is EFSOP® off-gas analysis; other off-gas analysis methods which cannot provide complete analysis of CO, CO2, H2 and O2 lack a necessary prerequisite for determining an online Mass & Energy Balance which is critical for efficient energy utilization and effective dynamic control of the melting and refining processes.





MAIN BENEFITS
• Dynamic Control & Optimization of the Melting & Refining Process
• Electrical Energy Savings
• Fuel Savings
• Reduced Power-On Time
• Increased Yield
• Reduced Tap Additions
• Electrode, Delta & Refractory Savings
• Reduced Tap-to-Tap Time
• Reduced Emissions

There are other add-on technologies that are available under the iEAF umbrella. We’ll elaborate on those in a future post.

For more information, contact:

Tenova Goodfellow Inc.
6711 Mississauga Road, Suite 200
Mississauga, ON
L5N 2W3 - Canada
Phone +1 905 567 3030
Fax +1 905 567 3899
goodfellow@ca.tenovagroup.com

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Thursday, January 22, 2015

#204 - Zamboni engine exhaust

Canada’s 2014 gold victory at the IIHF World Juniors was great fun for Canadians especially. But in general, the speed of play and puck handling during the World Junior tournaments is always a marvel to watch.

FRANK GUNN / THE CANADIAN PRESS


And we found this fun pic
for the Habs fans on Pinterest.


Explanations of the physical mechanics of ice skating have evolved over the years. From Wikipedia
A skate can slide over ice because the ice molecules at the surface cannot properly bond with the molecules of the mass of ice beneath and thus are free to move like molecules of liquid water. These molecules remain in a semi-liquid state, providing lubrication. 
It had long been believed that ice is slippery because the pressure of an object in contact with it causes a thin layer to melt. The hypothesis was that the blade of an ice skate, exerting pressure on the ice, melts a thin layer, providing lubrication between the ice and the blade. This explanation, called "pressure melting", originated in the 19th century. This, however, did not account for skating on ice temperatures lower than −3.5 °C, whereas skaters often skate on lower-temperature ice. In the 20th century, an alternative explanation, called "friction heating", was proposed, whereby friction of the material was causing the ice layer melting. However, this theory also failed to explain skating at low temperature. In fact, neither explanation explained why ice is slippery when standing still even at below-zero temperatures.



Professor Gabor Somorjai of Lawrence Berkeley National Laboratory has studied the mechanics of skating and has found that an ice skate blade actually glides on vertically vibrating ice molecules that behave in a ‘liquid-like’ manner without actually melting and turning into liquid.


Many hockey players and coaches agree that good skating is a combination of strength and technique. But smooth skating and puck-handling are also enabled by a device that is usually activated when no skaters are on the ice. A resurfacing machine is used to wash the ice, shave the surface, and leave behind a layer of water that will freeze to form a fresh layer of ice. One of the most well-known examples in North America of an ice resurfacing machine is the Zamboni.

In 1949, Mr. Frank Zamboni developed the world’s first ice resurfacing machine. Based on a Jeep chassis, this machine automatically and quickly provided all of the necessary operations required for pristine skating ice. It also had built-in reservoirs to collect the old shaved ice and distribute the new ice-making water.




Newer Zamboni models are available with electric power supplied by rechargeable batteries. However, many of the Zamboni engines are powered by gas, propane, or CNG (compressed natural gas), similar to fork lift trucks. With an internal combustion engine, there will be an exhaust gas flow. Because these vehicles function indoors in a populated environment, it is important to keep the engines in good repair to minimize impact on indoor air quality.



Nova has various gas analysis capabilities including the gases that typically make up engine exhaust. Our 7460 Series Portable Engine Exhaust Analyzers are available in various combinations including O2, CO, CO2, HC, & NOx. Our customers have used this analyzer on diesel, gasoline, propane, or natural gas powered 2 and 4 cycle engines.

The 7460 Series is a portable analyzer that uses infrared and electrochemical sensors / detectors. Here it is in our on-line catalog.



We aren’t engine mechanics. However, we do build these analyzers to meet Bar 97 and ISO 3930/OIML R99, Class O specifications. Therefore, many mechanics have effectively used this analyzer for reliable engine tuning and emissions reduction. We have noticed that this analyzer is also popular among equipment mechanics who work on forklifts and other non-road vehicles such as Zambonis.

Added March 2013 - We have noticed that our fork-lift customers frequently print on the analyzer cabinet the target gas readings for a properly tuned engine. For example, we have a couple of units in the Nova lab right now being calibrated for one of our customers. They have printed the following target gas readings on the analyzer:

O2: 0.8 % to 2.0 %
CO: 0.1% to 0.8 %
CO2: more than 11.0 %
HC's: less than 200ppm

If you are in the business of tuning engines and require analysis of engine exhaust, ask Mike or Dave for help with the 7460 Series Gas Analyzers.

If you're a Leafs fan, there may not be anything we can do to help you.

1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com


Zamboni pics from Zamboni website.

Thursday, January 15, 2015

#203 - Nova Analyzers from the Field – Episode 10 – Fuel Cells and Hydrogen Analysis

Measuring hydrogen (H2) is something we do a lot of here at Nova. We can measure it in a mixed background of other gases, or in a binary mixture of H2 in one other gas such as O2, N2, Ar, etc.

One application that generally requires H2 analysis in a binary mixture with N2 is fuel cell operation and development. We were sent some pics a while back from a fuel cell manufacturer. They use Nova instruments to measure H2.



From Wikipedia, a general description of fuel cell operation is as follows:
Fuel cells come in many varieties; however, they all work in the same general manner. They are made up of three adjacent segments: the anode, the electrolyte, and the cathode. Two chemical reactions occur at the interfaces of the three different segments. The net result of the two reactions is that fuel is consumed, water or carbon dioxide is created, and an electric current is created, which can be used to power electrical devices, normally referred to as the load.



At the anode a catalyst oxidizes the fuel, usually hydrogen, turning the fuel into a positively charged ion and a negatively charged electron. The electrolyte is a substance specifically designed so ions can pass through it, but the electrons cannot. The freed electrons travel through a wire creating the electric current. The ions travel through the electrolyte to the cathode. Once reaching the cathode, the ions are reunited with the electrons and the two react with a third chemical, usually oxygen, to create water or carbon dioxide.
  
The most important design features in a fuel cell are:
  • The electrolyte substance. The electrolyte substance usually defines the type of fuel cell.
  • The fuel that is used. The most common fuel is hydrogen.
  • The anode catalyst breaks down the fuel into electrons and ions. The anode catalyst is usually made up of very fine platinum powder.
  • The cathode catalyst turns the ions into the waste chemicals like water or carbon dioxide. The cathode catalyst is often made up of nickel but it can also be a nanomaterial-based catalyst.

In the specific project from which the field pictures were taken, the requirement was for measurement of 0-100.0 % H2. The sample is typically 70-90% H2 in balance N2, and is obtained at the anode portion of the fuel cell. Measuring the H2 here is useful in evaluating what the cell’s power output will be.

The sample itself is clean and basically dry, with the possibility of occasional moisture in some operation conditions. The gas analyzer has a condensate collection system and a liquid block membrane to avoid water infiltration to the detector. The sample gas is under pressure up to 1.2 barg (17psig). The analyzer has a built-in regulator. The fuel cell manufacturer uses a peristaltic pump to push the sample that is vented out of the analyzer back into the process to maintain the system gas composition.

Connection to the analyzer itself is quite simple, as shown in this picture.



One potential safety concern is related to the possibility of a gas leak occurring inside the analyzer cabinet. We can offer an ex-proof leak detector that is mounted in the cabinet which will de-power the analyzer in the event of a leak. To actively dilute a potential leak, we can also arrange a continuous vent flow through the analyzer using a fan. This is only suitable in clean environments with stable warm temperatures.

On this project, the fuel cell manufacturer and end-user have been very happy with the Nova units. They have since ordered a few spare filters in anticipation of normal maintenance.

For information on these and other gas analyzer systems, give Mike or Dave at Nova a call, or send us an e-mail.

If you have any Nova instruments at your plant or lab and want to share a couple of photos, feel free to send them to us along with a brief explanation of your application.

1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com
http://www.nova-gas.com/


*Fuel cell diagrams from Wikipedia, in public domain.
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Friday, January 9, 2015

#202 - GE 7216 V2.2 H2 Analyzer available at Nova

Over the years, we have had many requests for an analyzer system called GE 7216 V2.1 or V2.2. We used to manufacture this product for GE. It was specifically for use as a stator leak detector on large electric generators. In time, some of the components and technologies used in this analyzer were discontinued and subsequently updated.

We have also noticed that the functionality of some of these systems has been impaired by moisture ingress over the years. On most sites, the moisture removal systems prior to the H2 detector have been designed and installed by the original generator provider. If these fail, moisture can enter the H2 detector and ruin it.

Even though the GE 7216 V2 is no longer available to electric power providers, we do have a couple of options to allow you to proceed with a solution.

Replacement detector assembly – If all of the other components on the system are functioning properly, and an updated detector is all that is needed, we may be able to provide a heated box assembly with the updated detector inside. This option is not available in every case, but may be worth inquiring about.



Replacement gas analyzer – The GE 7216 V2 product was in production quite a number of years ago. Many of the installations are getting old or have been contaminated with water, and require replacement instead of repair. The Models 430VN4 and 430QN4 Continuous Hydrogen Monitor are available for this purpose.


The various components are now protected inside a common NEMA 4 wall-mount cabinet. The H2 reading is displayed locally on the analyzer cabinet, and is also sent to an analog 4-20mA output. As an option, we can make this an isolated or non-isolated output. We can also provide a hydrogen alarm with indicator light and relay contact.

The slight difference in model numbers designates the design of moisture removal system. Some installations have a supply in instrument air already connected to the old 7216 module. The new 430VN4 can also utilize this air supply. If there is no instrument air available, the model 430QN4 can be used instead.

If you have a 7216 and are experiencing age- or moisture-related problems, we can undoubtedly assist you. Contact us by e-mail. Be sure to state your 4-digit serial number and full model number.

1-800-295-3771
websales at nova-gas dot com

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