Reporting on the business and technologies
driving today's global industrial gas industry

GAWDA Gives Back
2008.06
Each year, the current GAWDA President and spouse choose a charity, in the city where the GAWDA convention is held, to be the recipient of the annual GAWDA Gives Back award. This monetary award, made up of donations from GAWDA members and associated companies, is a way for GAWDA to express its thanks to the city that hosts its annual convention. This year’s President, Gary Stoneback, and his wife Liliana, chose The Ranfurly Home for Children in the Bahamas as the 2008 GAWDA Gives Back recipient.
 
In 1956, The Ranfurly Home for Children was established in the Bahamas as a place where children who found themselves alone, abused, or without adult care for whatever reason, would be welcomed. Children at the Home range in age from five to twenty three and the Home welcomes all children regardless of race, gender, or religion. Children remain at the Home until they have graduated from high school or college, are working, or have been placed with a family member who can care for them.

To give you an idea of why the Stonebacks chose the The Ranfurly Home for this year’s Gives Back, here are some of the main objectives the Home has for the children in its care:

•Maintain and educate children until they are fit and able to support themselves.

•Help young adults find jobs and prepare them to support themselves when they leave the home.

•Guide children to becoming responsible Bahamian citizens through proper running of the Home.

•Alleviate suffering so that delinquency might be prevented, but in no way be a place of delinquency or punishment.

The Home currently has three dormitories, a kitchen, a study room, living room, computer room, and dining facility. But, The Ranfurly Home currently has no way of separating the small children from the young adults. This set-up makes it difficult for the Home to meet one of their main objectives — transitioning the older children successfully into society — and this is where the Stonebacks and GAWDA come in. All funds raised for this year’s GAWDA Gives Back will be used to fund the new dormitory being built for young adults who are ready to begin transitioning from the Home into independent living.

In his speech to GAWDA members at the Miami Spring Management Meeting, Gary Stoneback emphasized, “The GAWDA Gives Back donation will provide a means for underprivileged children in the Bahamas to be educated in such a way that enables them to succeed in life; I can tell you with confidence that your donations are going to be very well spent.”

The Ranfurly Home is not allowed to carry a mortgage and must raise all monies to pay for the dormitory before it can be built. The Home’s primary sources of income come from fundraisers, appeal letters to individuals, and a grant from the Bahamian government, and the current cost estimate for the dorm is $260,000. So this year, GAWDA Gives Back has a chance to make a real difference to the lives of many in the Convention’s host city.

Last year, with a goal of $75,000, the program was able to give over $114,000 to the Hamilton Family Center of San Francisco, $38,000 more than expected. Matching or exceeding that milestone would mean that a lot of children could live more comfortably at The Ranfurly Home.

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The Art of Selling
Even in God′s Silence, There is an Answer...
By Art Waskey
2008.06
An inexperienced rep sat across from me; he was depressed and dejected after a long unsuccessful week in outside sales. "I never realized it would be so hard: facing rejection from prospects, listening to customer complaints, and just trying to figure out what I should be doing next. I never realized how difficult serving the customer could be!"

What words of encouragement does a seasoned mentor provide a dejected young rep with tremendous potential, as he struggles to become an accomplished sales professional?

A timeless source of motivation is Og Mandino's "inspiration of the ages," The Greatest Salesman In The World. The Legend of Ten Marked Scrolls was just what the doctor ordered to encourage the young man in accomplishing his life's goals.

Scroll I: Commitment. Today I begin a new life. I will form good habits and practice them faithfully.

Scroll II: Love. I will greet this day with love in my heart. I will love all manners of men for each has qualities to be admired, though some may be hidden. I will always love myself.

Scroll III: Persistence. I will persist until I succeed. I may fail often before I succeed once.

Scroll IV: Miracle. I am nature's greatest miracle. I am here for a purpose. I will display my uniqueness in the marketplace.

Scroll V: Time. I will use this day as if it were my last. If I waste today, I forfeit the last page of my life.

Scroll VI: Emotion. Today I will be the master of my emotions. I will master my moods and control my destinythrough positive action.

Scroll VII: Laughter. I will laugh at the world. Laughter is the quickest way to stand up and start all over again, after life knocks you down.

Scroll VIII: Value. Today I will multiply my value a hundredfold. To surpass the deeds of others is irrelevant; to surpass my own deeds is outstanding.

Scroll IX: Action. My dreams are worthless, my plans are dust, my goals are impossible without action. I will act TODAY!

Scroll X: Guidance. Who is of so little faith that in a moment of great disaster or heartbreak has not called to his God? The guidance you seek will come: even in God's silence, you will find your answer!

The young salesman left our meeting determined to persevere. Reflecting on the Scrolls over time, he has gone on to a highly successful career. On occasions when our paths cross, he'll reminisce on the time he wanted to give up, but rejoices now that he has succeeded with a rich career in a profession to which he was truly called.

Art Waskey is Vice President of Sales and Marketing for General Air Services and Supply Company in Denver, CO, and author of The Art of Sales in One Month and his newly released Art of Sales in a Second Month. He can be reached via e-mail at awaskey@generalair.com

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The Saf-T-Corner
A Fresh Set of Eyes — Spotting Overlooked Safety Violations
By Jim Herring
2008.06
We were shopping for a new insurance carrier and invited several companies to provide a bid for the coverage. Each company sent a field inspector to our plant to determine whether they would consider insuring our business. I chose to view this as an opportunity to have several "free" safety inspections of our entire operation.

Three different insurance companies responded with a field inspection, and I have to admit, I learned some valuable lessons during each inspection.

For the most part, we received a lot of validation that our overall safety programs here at Saf-T-Cart were effective. For example, one inspector praised our efforts in placing earthquake barriers on the tubing shelves that are loaded several feet in the air. Another was impressed with the fact that we do not have any gas cylinders in the welding areas. All the gases at Saf-T-Cart are piped directly to each individual welding workstation. In addition, all three inspectors made note of the fact that our employees always wore the proper eye protection when they were inside the plant. Each of these safety "efforts" was cited as a contributing factor in keeping our premiums in check.

Each inspector, however, also found numerous things that were causes for concern, like tools or other equipment left on the floor blocking an aisle, or a pile of dirt or debris in a corner that should have been cleaned up but had been overlooked. There were lots of other "little things" that should have been taken care of on a day-to-day basis, but had just become part of the landscape, so to speak.

These "inspections" were not a waste of time. We got a reasonable rate on our new policy, and we took advantage of the opportunity to clean up our act and correct a lot of minor, and some not so minor, safety violations. These inspections were made by private insurance companies, not OSHA, and we could make corrections without penalty. Had OSHA done a spot inspection, we may have had to pay fines.

At Saf-T-Cart, we believe we make an effort every day to be as safe as possible. As this column illustrates, however, a second set of eyes can often find things we tend to overlook on a daily basis. It's a good idea to have an outsider take a walk through your facilities from time to time. If you don't have access to a new set of eyes, refresh the ones you do have. Get out of the plant from time to time. Attend a GAWDA meeting or some other industry function. Take a vacation. Play a round of golf. Enjoy some time with the family.

Then walk through your facility and look at things with a fresh set of eyes. Trust me, you'll be surprised by what you see.
Until next time, be safe.

Jim Herring is Vice President of Marketing and Procurement at Saf-T-Cart in Clarksdale, Miss. He can be reached via email at jim@saftcart.com.

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Basic Cryogenics — That Even I Can Understand
Liquid Traps — Minimizing Heat Leak Through Piping Circuits
Keith Hall
2008.06
PIPING DESIGN
Other than structural integrity, the most important engineering design concern for a cryogenic vessel is thermal efficiency. In “Basic Cryogenics,” Cryogas International, March 2007, pp. 41–42, we learned about heat transfer as related to cryogenic vessels, i.e. solid and gaseous conduction, and radiation. In this column, we discuss the conduction of heat through the piping into the cryogen contained within a vessel.

When designing a cryogenic vessel, our goal is to minimize the heat that is transferred into the cryogen, as it causes the liquid to boil and the pressure within to rise. In addition to the heat that may be conducted via the internal supports, which suspend the inner vessel within the outer vacuum jacket of a cryogenic tank, heat may also be conducted into the liquid by way of the tank’s piping. Like the internal supports, a vessel’s piping creates a thermal circuit (heat path) for the conduction of heat from the warm ambient environment to the cryogen contained within the inner vessel.

One way to minimize heat transfer through piping is to design the piping with as long a heat path as is practical. Think of the poker left in the fire as an example of a heat path. On a cold winter night, if you stoked the fire and left the poker in the glowing embers, you could retrieve the handle end without injury, provided the poker was two feet long. However, if the shaft of the poker was only 6-inches long, you would need to put on an insulated glove to grab the poker. From practical experience, we know that there is a thermal gradient along the length of the fireplace poker; the glowing orange tip being the hottest, with the temperature gradually decreasing along the length of the handle to a point where it is at ambient temperature.

Similarly, the design intent for piping on a cryogenic vessel is to make the heat path as long as practical. We would like the piping, which is exposed to our “hot” (comparatively speaking) external environment to be as long as reasonably possible as it passes through the vacuum space to the inner vessel. A long heat path ensures that the piping is not warm where it enters the inner vessel; and there is no conduction of ambient heat into the cryogen.

By making the piping in the annular space as long as practical, we also solve another engineering problem; that of the flexibility of the piping. The inner vessel of a cryogenic tank and the piping both thermally contract (shorten) when filled with cold product, and expand when the tank and piping are empty and warm. From practical experience, we all know that a long length of piping is much more flexible than a short length of pipe, i.e., if a long pipe is held horizontally at the center, both ends will sag. Thus we can see that longer piping will also serve to better accommodate the stresses caused by thermal contraction and expansion.

In summary, making the internal piping as long as practical helps resolve both the flexibility concern due to thermal stresses, while also providing a long, more thermally efficient, solid conduction heat path to the inner vessel.

LIQUID TRAPS
Generally there are three liquid piping lines, at a minimum, on each cryogenic tank: The Pump Inlet, or Fill and Drain; The Pressure Building Unit Inlet; and the Liquid or High Pressure line to the differential pressure liquid level gauge.

Cryogenic valves on piping lines are located as close to the tank as possible, yet the cryogen contained within the short liquid line from the piping penetration on the outer vessel to the closed valve is exposed to warm ambient temperature. The liquid between the valve and the vessel will boil profusely and turn to vapor. As we know, when cryogenic liquid boils and turns to vapor, it expands 700 to 900 times in volume (see “Basic Cryogenics,” Cryogas International, January 2007, p. 43). This heat leak would cause boiling liquid to continually flow into the exposed portion of the piping as the resulting vapor bubbles back up through the product contained within the vessel. The pressure in the tank would rapidly rise and soon lift the relief valve, and the product hold time would greatly diminish. Therefore, when storing cryogenic liquids we do not want liquid to remain in exposed piping; we will settle for vapor to be contained therein, as gaseous conduction of heat is not as severe as solid conduction of heat into the liquid.

The design challenge is to design liquid lines so that when a cryogenic vessel is not being used, liquid is pushed back inside the tank, as close as possible to the cold inner vessel. The solution is to design an inverted trap, located in the vacuum space, on each liquid line.

We are all familiar with the “U” shaped traps used in the drain plumbing under our kitchen sink. The bottom portion of the “U” is lower than the exit side of the drain trap, effectively trapping water in the bottom of the trap. This serves to block the foul smell that would otherwise emanate from the drain piping.

A similar liquid trap design is used on the liquid lines contained within the vacuum insulated annular space of a cryogenic vessel; the only difference being the trap is inverted; the ‘U-shaped” portion of the piping is turned upside down.

The basis for this simple, yet elegant, design is that a vapor, being less dense than liquid, rises. Just as a scuba diver’s exhaled air bubbles rise, so does vapor. Bubbles do not naturally want to be pushed downward.

With the inverted “U” trap piping design, when a cryogenic liquid valve is closed, the liquid within the exposed portion of the piping immediately begins to boil and turn to vapor. The vapor naturally rises up into the top of the inverted “U” portion of the piping and becomes “trapped” unless forced down the back side of the trap, or in essence is “burped” back over the trap and into the inner vessel. This “burping” over the trap will continue until the pressure in the external piping equalizes with the pressure inside the tank. Once the pressure of the vapor in the tank’s external piping equalizes with the pressure inside the tank, only vapor will remain in the piping from the closed external valve to the top of the inverted trap located in the annular space. This vapor pressure pushes against the liquid, “trapping” it at the back (down side) of the inverted “U”, where the liquid is close to the cold inner vessel.

From an intuitive standpoint, it may seem that adding a trap in the annular space would require the outer vessel to be longer that it would otherwise be, but that may not be the case. On horizontal tanks, for example, instead of aligning liquid traps parallel to, or in-line with the length of the tank, they are designed transverse, to minimize the over- all length of the vessel.

Liquid traps are not limited to the inverted “U” shape. Often liquid traps are designed with a greater circumferential loop than a simple inverted “U”. Often, an enhanced trap design provides a better location for the piping to exit the outer vessel, creates a longer heat path, and provides greater flexibility in the piping to accommodate thermal contraction and expansion.

A similar trap design is the “candy cane,” to which line relief valves are typically attached on external liquid piping.
If liquid can be trapped between two or more closed valves (or check valves, depending upon the flow direction), a line relief valve must be used to protect the piping from over-pressurization. Trapped liquid warms and greatly expands into vapor. Without a relief valve, a catastrophic rupture of the piping would occur. With the candy cane design, warm vapor is trapped at the top of the candy cane, with the line relief valve being attached to the short or warm leg, effectively forcing the liquid down the long leg (inlet side) of the trap. This serves to maintain warm vapor near the relief valve and not expose it to the cold liquid.

Keith Hall is the Engineering Manager at Cryogenic Vessel Alternatives, located in Mont Belvieu, Texas (near Houston). He can be reached at KHall@cvatanks.com

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Energy Initiatives
Redefining Ceramic Fuel Cells
by Timothy LaBreche
2008.06
Wikipedia’s community of experts can’t overcome incorrect assumptions on the emerging alternative energy space. Wikipedia’s solid oxide fuel cell (SOFC) entry, which describes SOFCs as devices that use a solid (ceramic) electrolyte to facilitate the generation of energy, notes that these fuel cells are “intended mainly for stationary applications.” In fact, leading innovators are proving that ceramic fuel cells can include small and light energy devices. Indeed, the future of alternative energy lies in the ability to deliver this portable power to market.

Portable power is the holy grail of alternative energy research. Small, lightweight energy devices bridge the gap between the current market leaders, batteries and gas generators. Batteries become heavier as power output rises, and gas generators become noisier and produce everincreasing pollution in tandem with increases in power output. In contrast, SOFCs deliver a wide range of energy output, between 20 and 250 watts, making them incredibly energy-dense for their weight and size.

Besides providing portable power, SOFCs offer a huge advantage over typical proton exchange membrane (PEM) fuel cells. PEM requires very pure hydrogen fuel, which is costly and difficult to obtain. In addition, PEM fuel cells require expensive platinum catalysts that are poisoned by many low-level contaminants such as carbon monoxide and sulfur. In contrast, SOFCs are fueled by readily available bottled propane or butane gas. Propane and butane are not expensive, and they are trusted and available at over 25,000 retailers in the US alone.

Along with the market shift to ceramic SOFCs is a shift from the traditional power generator manufacturing model, which was based on a limited number of very large custom-built utility installations. Portable power devices, including SOFCs, represent a new breed of mass-produced generators that are compact and lightweight.

A NEW TYPE OF SOFC
Portable SOFCs based on a small tube design were originally developed by Professor Kevin Kendall of the University of Birmingham in the UK. Kendall realized that the disadvantages of the traditional SOFC design could be avoided if thermalshock- sensitive planar stacks, or large tubes, were replaced with small tubes of a few millimeters in diameter.

Small tubes relax the design constraints of SOFCs’ high operating temperature (600–900ºC). The active part of a small tube can be hot, while a short distance away the cold end of the tube can be sealed with simple rubber. The small tube design eliminated two of the major disadvantages of SOFCs — problems with hot seals and thermal cycles.

Figure 1 shows a 20-watt generator. Although the active membranes are at SOFC temperatures of around 700ºC, the generator is only slightly warm to the touch and the exhaust is cooler than body temperature (see Figure 2). These generators operate in a range of field conditions from artic cold to desert heat (- 40 to 50ºC).

THE FUTURE OF SOFCS
Complete SOFC power systems, fueled by ordinary bottled gas, are being manufactured to produce complete hybridized power just seconds after pressing a simple “on” button. Intended for rugged, all-weather field use, these generators are designed for construction sites, military use, or off-road/off-grid power. The market for this type of SOFC product is limited only by current demand.

The small tube design was used as the basis of these portable SOFCs, which were developed for the US Defense Department under the Defense Advanced Research Projects Agency (DARPA) Palm Power program. Starting around the size of a lunch box, the generators are small, lightweight and reliable.

These durable portable generators may be dropped, shaken or otherwise handled roughly and remain intact. In fact, one of the most promising applications for SOFCs is use in small, unmanned aerial vehicles (UAVs). Combining a low-mass, shock-proof design with the inherent durability of a small ceramic tube, SOFCs can deliver a powerpod for UAVs that can not only survive the rigors of take-off, flight and successful landing, but also emergency landings.

A NEW TYPE OF CERAMIC MANUFACTURING
Instead of conventional ceramic fabrication methods, these generators are produced through ceramic powder that is loaded in thermoplastics to undergo hot extrusion. Ordinary wet ceramic extrusion produces a soft tube, which forms a weak and brittle green tube after slow drying. In contrast, thermoplastic extrusion provides fast cooling to produce a strong and flexible green tube that can be manufactured with thinner walls. Thermoplastics do require binder burnout, which can be a problem with large sections but is no problem for thin-walled tubes.

The major advantage to this new thinking on ceramic fabrication is the combination of anode and electrolyte by extruding several of these two different materials at the same time (co-extrusion). Combined with the size reduction as the plastic materials are pushed through an extrusion die, it is possible to produce complex micro-scale features (microfabrication). In fact, a microfabrication by coextrusion process was developed to manufacture nearly complete tubular cells with electrolyte layers only 10–20 microns thick. (This process was developed and patented by Adaptive Materials, Inc.)

Figure 3 shows a 10-micron-thick zirconia electrolyte on a multilayer anode. Significant size reduction occurs during coextrusion.

Subsequent fabrication involves the usual ceramic sintering steps, followed by assembly operations to produce completely wired-up individual cells. Combining everything into a small package, a ceramic microreactor is placed in each cell so that simple propane fuel can be used directly in the cells.

To make a generator, the appropriate number of cells are collected into stacks, assembled inside an efficient ceramic thermal insulation package, and fitted to a cold manifold so that fuel and air can be easily introduced. This produces the SOFC stack, a ready-to-use unit. A compete generator system is made by combining the stack with the “balance of plant,” including pumps, valves, control circuits, displays and a storage battery. The battery is important for hybrid power, supplying the dynamic variable power required by the users’ various duty cycles while being continuously charged by the fuel cell.

THE ROAD TO MASS PRODUCTION
The markets that adopted SOFCs early are well established. Some are motivated by environmental concerns, others by the need for more power than batteries can supply. Some are frustrated with inefficient generators, while others want to be the first to take advantage of an innovative new technology.

Applications for SOFCs exist in the leisure, medical, military and industrial markets, and demand in emerging commercial markets is strong. As the need for portable power continues to expand, so does the market potential — fueled by readily available fuel sources and made possible by ceramics.

Timothy LaBreche is Director of Technology at Adaptive Materials, Inc., Ann Arbor, MI. For more information, contact Adaptive Materials, Inc. at 5500 South State Street, Ann Arbor, MI 48108; (734) 302-7632; fax (734) 222-9283; e-mail jeff.basch@adaptivematerials.com; or visit www.adaptive materials.com.

This article is reprinted with permission from the April 2008 Global Spec Ceramics and Glass Newsletter.

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