Are Bulk Cryogenic Spot Drops a Good Thing?- Part II – Supplier Perspective

In the last episode it was determined that it is costly for cryogenic bulk transports to return home with any of the liquid they departed with. One way to make it home empty is to drop off any liquid remaining after scheduled deliveries at some other customer tank that has some room available. Ideally for the supplier, this would convert the left over liquid from a cost to income. It was asked, “Is this a good thing?” First, we’ll look at the supplier side with the question, “Did the revenue generated offset the cost of an 800 gallon delivery considering that Company X typically hates to deliver under 1500 gallons at a time?”

Here, again, comes The Millennium Answer. The Millennium Answer came into vogue shortly after some high placed U.S. politico said something to the effect of “It depends on your definition of the word ‘is.’” Ever since then it seems everything is contingent. i.e. “It depends.” In this case- It depends on the cost of getting to a drop location and making the fill compared to the revenue that might be generated. Pretty simple, eh? But, not necessarily as simple as it appears on the surface and especially when asking about dropping off 800 gallons where 1500 is preferred.

The dependant aspect of whether 800 gallons is a good drop or not relates to whether it is the (first/only) drop or whether it is the last drop. 800 gallons as a first or only drop is not necessarily a profitable proposition for a bulk supplier. Costs associated with running a 4000 or 6000 gallon transport out on a unscheduled single drop delivery might just exceed any revenue that could be made. This is especially true with lower priced products like liquid nitrogen.
On the other hand, delivering 800 gallons (or even significantly less) as a convenience drop at the end of a route is markedly different. In this case, the costs associated with getting the transport loaded and out into the market place have already been incurred and the liquid is out there. Now, there is just the incremental cost of getting to another location and offloading versus the revenue that could be generated from the drop. Playing to the profit side of this equation are the opportunity costs of not doing the delivery:

- Liquid that would just vent off if left in the transport or be partially lost transferring back in and out of plant storage;
- Slightly higher fuel costs with the load,
- The need to return to the convenience drop site sooner by not having made the drop and not having enough liquid to completely fill the tank when the delivery is made.

All things considered-convenience drops are usually good for the bulk cryogenic liquid supplier as long is the drop is within relatively close proximity of the last scheduled stop or the return route home.
But then……. Are convenience drops good for the customer?

Golf as a Metaphor for Cryogenic Liquid Delivery

Are Bulk Cryogenic Spot Drops a Good Idea?

For the sake of collective sanity- Let’s agree that business profits are good and necessary. Bulk Cryogenic Liquid Suppliers have a number of challenges to overcome in order to turn a profit at the end of the day. Others will be explored over time, but one that is universal is transportation costs. One element of this is how many miles must be traveled to deliver a given quantity of liquid oxygen, nitrogen or argon. For more effort than most of us can imagine goes into trying to optimize this ratio.

Yesterday a good friend used a golf metaphor for business that applies. To wit- He wants his business to operate like a golf ball. When you hit a golf ball out there it stays out there and doesn’t come back. All returns are costly and one of the most important things that can be done with cryogenic liquid delivery is to be sure that all of the liquid that leaves the plant stays out.

One way that delivery companies help assure they are able to do this is to identify bulk tanks that can be used as field receivers for liquid that is left in a truck at the end of its route. So, for instance, a liquid nitrogen truck drives out to a suburb area and delivers 5200 gallons of its 6000 gallon load to clients. The 800 gallons that might be returned to the plant is now a liability. To avoid returning it, the driver might go to a client that did not call in for delivery, but has a 9000 gallon tank that always has some room in it and drop off his remaining liquid He now comes back empty and converted the 800 gallons he had from a cost to revenue.

Is this a good thing?

Did the revenue generated offset the cost of an 800 gallon delivery considering that Company X typically hates to deliver under 1500 gallons?

Is this a good thing for the client that received this drop?

Manana (later).

DOT 4L- 292 Liquid Cylinders with 230 Reliefs?

At the end of the last episode the client had run out of 4L-200 liquid cylinders and was wondering if they could put 230psi reliefs on some of the 4L-292 oxygen liquid cylinders they had remaining in stock to get them through for a few days until their regular delivery. This left the questions of:

- Is this OK?
- Why or why not?
- What other considerations might there be?

First, the fact that the vessels are oxygen is irrelevant to the issue of the pressure relief setting. The important issue in all this is the DOT 4L designation.

What matters is the fact that the maximum allowable relief setting on a 4L-200 is 230psi and it is 350psi on a 4L-292. Technically, it is OK to de-rate a vessel by putting a lower pressure relief than is allowed. So “yes” this is OK.

The other consideration, though, is where the rub comes in. If you look at the factory setting for the pressure builder (PB) regulator on a 4L-200 you’ll find that it is 125psi in most cases. The factory setting for the PB regulator on a 4L-292 is more typically about 300 psi. The problem then with putting a 230psi relief on a 4L-292 cryogenic liquid cylinder is that the pressure builder is set at a level higher than the relief. So, the liquid cylinder will try to build pressure to the PB set point, but constantly vent causing the vessel to exhaust itself. If you want to switch out the relief to 230psi on a 4L-292 you need to remember to reset the PB.

It is common for people to put 230 reliefs on 4L-292s without taking the PB setting into consideration. Likewise, checking the PB setting is one of the trouble-shooting steps to do when a liquid cylinder is reported as “bad” (constantly venting). The liquid cylinder might actually just be doing what it is set up to do.

www.westcryogenics.com

DOT 4L Cryogenic Liquid Cylinder Pressure Relief Change

A large production and research facility has multiple uses for cryogenic liquid cylinders and keeps an inventory of DOT 4L-100, 4L-200 and 4L-292 vessels on site. The 4L-100s are set with 22psi reliefs and installed in labs and a few other locations where they are used strictly for liquid withdrawal. The 4L-200 “medium pressure” vessels are the most commonly used liquid cylinders throughout the facility and are fitted with standard 230psi reliefs. There are also some higher pressure applications at the site where 4L-292 vessels fitted with 350psi reliefs are needed.

Liquid nitrogen, oxygen and argon vessels are normally delivered to this site every Thursday. Mid-morning one Tuesday, they empty a 4L-200 oxygen liquid cylinder at a location that has a maximum feed pressure of 260psi. On arrival at the inventory area they find that their supply of 4L-200 (230psi relief) liquid oxygen cylinders has been exhausted. There are, though, a few 4L-292 (350psi relief) liquid cylinders still on hand. They call to find out if they can take a 230psi relief off an exhausted 4L-200 and put it on a 4L-292 in order to use the 4L-292 at the process area that cannot exceed 260psi.

What is the answer?

Why?

Are there any other questions or considerations that need to be reviewed related to this answer?

Tune in next time…….

Temperature Effects on Gas Pressure

It is often hard to comprehend just how big an impact increased temperature can make of the gas pressure within a cryogenic liquid cylinder or bulk tank containing oxygen, nitrogen or argon.

My good friend Greg Cain at Oxylance provided the following information which is just slightly edited:

“One of the things that you may want to put in there to show people the gas volume / temperature is as follows.

Take a plastic bottle. The 1 liter size makes a bigger impression but a 16 or 20 oz will also work.

Get it warm and dry and put the top on it very tight. Stick it in the freezer for about 15 minutes and pull it out. As the air inside the bottle cools down the air molecules become smaller (more condensed) and the bottle will pull a vacuum on itself and when you take it out it will be half its normal size. The temperature difference will only be about 40 degrees (from 70 down to 30).

Now let the bottle warm back to room temperature by taking the lid off and get the bottle out to its normal size. Put the top on it tight and try squeezing it and see how soft it is. Remove the top and put the warm bottle and top back in the freezer. Leave it in there for 15 minutes. Reach in the freezer and put the top back on very tight and set it out in the sun. After it warms up try squeezing it and see how stiff the bottle is. A difference of 40 degrees will make the bottle so stiff you can’t squeeze it. Now think about how much difference it would make if you were going from -296 to +70 degrees.”

This last sentence is in reference to liquid nitrogen, oxygen or argon which have boiling points nearly 400 degrees F from what we consider to be room temperature.

Thanks, Greg!

Two Secrets to Business Success

Long ago I was told of the young man who was taking over ownership of a business after mentoring for many years at the right hand of the coumpany's founder. On the day the founder was leaving for retirement he asked his successor if he had any other questions.

“Just one,” said the younger man. “Could you just summarize for me what you consider to be the keys to business success?”

“Of course, that’s easy. There are two simple things,” replied the founder. “First, keep whatever commitments you make to a client, no matter the cost or time involved.”

“And the other?”

“Don’t make too many stupid commitments.”

I mention this in lieu of a new product announcement that needs a little more work prior to release. But- as my buddy who spent way too much time on the islands always says “Soon Come.”

Cryogenic Liquid Cylinders- Safe Handling

I recently wrote about safety concerns related to lifting cryogenic liquid cylinders overhead. A number of questions have been received related to safe methods for moving and handling liquid cylinders. Rightfully so as there are a lot more liquid cylinders moved along the ground than lifted overhead. In turn, there is a lot more opportunity for injury and damage resulting from improper handling.

What are the risks related to moving liquid cylinders?

- Back, muscle and joint strain
- Broken bones
- Crushed toes, feet, fingers and hands
- Cuts from cracked or broken handling rings and site glasses.
- Damage to liquid cylinders that are dropped or tipped over including broken necks and inner leaks
- Broken site gauge and covers
- Damage to other equipment or fixtures hit by a dropped liquid cylinder

There are a number of resources for information on proper care and handling of liquid cylinders including manufacturer’s operating instructions and CGA Publication P-30 which can be purchased and downloaded on line. We’ll also continue to hit items here.

One for today is the suggestion that cryogenic liquid cylinders be moved using a safe cart or carrier. This is especially true for full liquid cylinders that commonly weigh from 650 to over 1000 pounds. Carts designed specifically for moving liquid cylinders have a hook that catches the hole in the handling ring support bracket. They also have wheels that the liquid cylinder rests on when tilted back to avoid reliance on brute force to keep the cart from dropping.

Nothing is ever a problem until if becomes a problem and then it is usually too late to get the toothpaste back in the tube. I get enough calls on this issue to know it is a frequent issue. This might be the best week yet to go do a little audit of how your folk are handling liquid cylinders and what improvements you might be able to make in your methods.

Cryogenic Liquid Cylinders- Safe Lifting Method

A few weeks ago we discussed some of the potential hazards and risks associated with lifting liquid cylinders to elevated locations along with ways not to lift them. It is agreed among all manufacturers that the handling ring around the top of a liquid cylinder is not to be used as a lifting point. While some instruction manuals show cryogenic liquid cylinders being lifted by the holes in the handling ring support brackets this is not a universally recommended practice. This is especially true regarding full cylinders being lifted overhead. The risk of lifting any liquid argon, oxygen or nitrogen vgls by the support brackets are that:

a) It is unlikely if you know the specific cylinder you are lifting is one with supports designed for lifting;
b) The liquid cylinder supports could have been weakened over time by being bent and straightened or through metal fatigue or corrosion.

In any case- the support brackets can tear away from the vessel allowing it to drop. A liquid cylinder full of product that is dropped from an overhead location is a clear hazard.

So- What are the options?

1) Consider running feed lines up from your vessel to the work area first and keeping all liquid containers at ground level;
2) If the distance from the ground to a work area is prohibitively long then use a safe carrier to raise the vessel to the area needed.

A photograph of an enclosed carrier for lifting liquid cylinders is shown. These can also be fitted with lifting eyes on all four corners for 4-point lifting. Be sure that whatever you use that the device is regularly inspected for damage or corrosion and that any lifting cables are in-spec for the intended purpose.

West Cryogenics Manufactures New Cryogenic Equipment in the U.S.

Yes. West Cryogenics manufactures brand new GOrilla & Ultra Cryogenic Liquid Oxygen, Nitrogen and Argon Tanks and Dragon Vaporizers in their ASME Code plant in Willis, Texas. And- clients are welcome to come and watch the manufacturing work being done. You can see everything from welding nozzles on heads and then welding the heads to shells and performing ASME pressure tests to seeing how super-insulation wrapping is done and vessels are sealed and mass-spec tested to be sure they are leak free. Then you can see the heated and cool vacuum processing, sand blasting, painting, and piping…… not to mention also getting to see cleaning materials for oxygen service and performing tests and analyses.

When you really think about it this ranks with touring the Blue Bell Ice Cream and Dr. Pepper plants except that manufacturing brand new cryogenic vessels in the United States is a lot less common than ice cream or soda pop. I have to say this in a very qualified manner, though, because it is a bit of an understatement to refer to Blue Bell simply as “ice cream” or Dr. Pepper as “soda pop.” It is more likely that they, in fact, are the very real modern personification of “milk and honey.” And well, you know, GOrilla Tanks, Ultra Tanks, and Dragon Vaporizers are mighty fine, too. And- They are all manufactured new in the U.S.

Cryogenic Vessels- Vacuum and Moisture- Part 2

So- How do you get frozen moisture molecules out of the annular space of a cryogenic vessel?

And- If they are frozen, they are immobile right? So are they hurting anything?

The first answer is heat. The only simple way to get molecules freed up and moving so they can be sucked out of a cryogenic vessels annulus is by applying energy. The problem is that this must be done indirectly. More specifically, we cannot blow hot air into the annulus to free up the molecules as this just puts molecules in and can tear up the super-insulation in a SI vessel. This means that you have to apply heat to the inside of the inner vessel and possibly also to the outside of the outer vessel.

With super-insulated cryogenic liquid cylinders this is fairly easily accomplished by inserting a thermostatically controlled electric heat rod into the inner vessel. With larger vessels and cryogenic bulk tanks it is necessary to blow in filtered, hot air or pure nitrogen. This is pretty inefficient and can be expensive, but might be the only option. Heat lights or strips can also be used for heating the outer vessel.

In any case, it is super-critical to avoid overheating in order to stay within specifications and avoid damage or stress to the inner vessel which will weaken it. By the way- this is one more reason why there is a DOT program for inspecting and authorizing DOT-4L vessel repair facilities. And- if you want to know if your vendor is actually a DOT 4L authorized repair center just ask them for their DOT “K” number. Real prudence will prompt you to also look and make sure they are affixing their “K” tag to all serviced vessels as required.

As far as hurting anything...... next post.....

Cryogenic Vessels are Moisture Magnets

It happens almost every day that someone accidentally cracks open a vacuum evacuation valve on a cryogenic bulk tank or springs a leak in a vacuum probe tube and WHOOSH! The vessel just lost all or a lot of its vacuum.

Referring back to one of the #1 Laws of Science—“Nature Abhors a Vacuum.” Given any opportunity at all, a vacuum space will find molecules and pull them in to recover atmospheric molecule levels. And, we’ve discussed this before.

Untouched, though, is the element of just what kind of molecules get sucked in when a vacuum goes south. The millennium answer: It Depends. What it depends on is the kind of molecules that are available to suck in. In humid environments, a lot of those molecules are going to be moisture (H2O). The problem with moisture is that it is a bear to get out of a vacuum insulated vessel’s annular space once it gets in. This is particularly true if the vessel has perlite instead of super-insulation in the annulus.

Q: Once molecules get into an annular space, how do you restore the vacuum?

A: The only way to restore really strong vacuum in the annulus of a cryogenic vessel is with a really good vacuum pump.

Q: And what is the central dilemma?

A: The stronger the vacuum the less energy there is in the vacuum space. Since energy equals heat that means that the moisture in the annular space will freeze out making it almost impossible to withdraw all the molecules.

We’ll discuss this, the effects and cures some more next post………

Oxygen + Fuel Cutting- Starving for Oxygen

Good news- We have unprecedented access to information.
Bad news- There is too much information.

Frustration with large tip cutting torch operations is common. Tips burn up and results just aren’t what are expected.

Enter easy-to-use gas flow guides like those published by Victor. It only took two of us who knew what we were looking for about 30 minutes to find them today online. They are probably easier to find if you are one person with less presupposed knowledge…….. or not. You can also just drop by your local welding supply and pick them up.

Anyhow- check out the flow requirement for a #8 tip and you’ll see the oxygen flow needed for a type 303M, GPM, GPN, GPP is 450 to 500 scfh. Go to a Type 1-101, 3-101 (Oxy-Acetylene) and the oxygen flow requirement is 900-1050 scfh. Back in the day when your #4 tips system was fed by oxygen gas 16- packs everything was fine. The only problems were the weight, size and cost so you go to a liquid cylinder and all is fine. That is until a #8 tip is needed and no one ever mentioned that the maximum 8-hour flow rate from a 180 liter liquid cylinder is 350 scfh +/- depending on the manufacturer.

Result- A big powerful torch that is now starving for air which is kind of like a Ferarri with a wet air filter….. all show and no go.

Solution: Additional vaporization.
New Result: More air; More cut. Maybe even a speeding ticket….

Leadership Side Note

I received notice this evening that the last Boy Scout who registered for our Venture Crew on my watch was awarded his Eagle Rank today. It is really hard for the uninformed to understand just what it takes for a young man to reach Eagle in Boy Scouts or a young lady to make Senior Presentation in National Charity league or Gold in Girl Scouts. Even more so- It is not what it takes, but what it gives for a young person to make the kind of commitment required to Eagle or Gold or make it all the way to Senior Presentation in National Charity League or graduate with a sash from National Honor Society or Key Club.

A prominent U.S. leader commented a few years ago on the decline of true leadership development programs for our youth and the value generated for society and the participating individual by them. It is hard to overestimate the value of the aforementioned programs and similar groups and no wonder that Universities and employers give so much credit for successful participation in them.

Yes- my son earned his Eagle, served as President of our Venture Crew and is thriving in college including participation in SIFE…. another great program. He served as a crew leader on five major treks including a 54-miler on the Appalachian Trail, certification of 18 scuba divers in San Marcos, Scuba and Island Adventure Treks in Florida, 5 days of diving in Cozumel and skiing in New Mexico. He also completed the BSA Junior Leadership and Venturing Leadership programs. And- my daughter is about to have her Senior Presentation in NCL and graduate with NHS and Key Club sashes. She has received awards for most philanthropic hours and has been accepted into the Honors College for next year at her University. She is also the founder of I am Human Like You which is a non-profit charity committed to fostering dignity and respect for homeless people.

They have both been blessed with one of the world’s most supportive and understanding moms who has been right along with them through all of this including hundreds of hours of her own time contributed to NCL, Scouts, Track, PTA, Hockey, Indian Princesses, church groups and more. They’ve all given me the best gifts possible by allowing me to tag along through a zillion of the greatest adventures anyone could ever dream of. As much of a pain or burden as I was in Scouting and Indian Princesses they never ran me off or quit because of me. I still have so much to learn from them and am so optimistic because of them and the future leaders like them.

SIMPLE NER Method for Checking Cryogenic Liquid Cylinder Vacuum Insulation

How do you know if a liquid cylinder marked "BAD" actually needs to be sent in for repair or if the “problem” is something that can be fixed at your shop? What is “BAD?” Is it venting too much or just doing what is normal? Or is the problem a leak or a stripped fitting?

Ideally, liquid cylinders with bad vacuums should be identified and separated from other “bad” vessels since it is clear that they will need to be sent in for rehab. Segregating those with bad vacuums also allows more focus time to trouble-shoot vessels that you might be able to repair yourself.

The SIMPLE NER test method was developed to provide an easy, clear-cut identifier for determining bad vacuums and procedures can be found in the West LCR Handbook at http://www.westcryogenics.com/Liquid_Cylinders.php. It allows for testing without instrumentation and in many cases shows there to be no problem with a vessel at all. Just a couple of weeks ago, a client called with a near urgent need to get a vessel shipped in and repaired. I walked him through hot-fill procedures in the morning and SIMPLE NER testing in the afternoon. The next morning we found the vessel was “fixed” and able to go back into service.

Cryogenic Liquid Cylinder NER (Normal Evaporation Rate) Testing

Full NER Steps include:

- Make sure your pressure builder and gas use valve are securely closed
- Open the Vent valve and connect a fill source to the liquid connection on the liquid cylinder
- Fill the Vessel with liquid nitrogen to “full” level by weight and leave the vent open allowing the liquid to fully stabilize (ie- until venting stops)
- If the vessel vents continuously for several (3-4) hours after filling and shows no sign of slowing down then check to make sure your pressure building line is not leaking past the valve. If it is then your pressure building valve needs to be rebuilt or replaced. If the PB is fine then stop the test and save whatever product you can as you already know that your vessel needs to be sent in for service.
- Now, top off liquid level to replace initially vented product
- Log the weight of the filled vessel and leave the vent open
- After 24 hours, reweigh the vessel and log this (minus vessel tare weight) as “Net Starting Weight”
- Measure the weight of the vessel in two successive 24 hour periods
- Subtract the final weight from the starting weight to determine the total weight of product lost. In all cases subtract the tare weight of the vessel so that you are just logging the weight of the product. (net weight)
- Divide the net weight of product lost by the net starting weight to get the percentage of loss over two days.
- Divide that figure by two to get the daily NER.

Cryogenic Liquid Cylinder Testing- NER Intro

NER is a TLA (Three Letter Acronym) for Normal Evaporation Rate. This is the expected boil off rate of cryogenic liquids due to heat incursion and associated temperature rise in liquid nitrogen, argon, or oxygen above their boiling points. As the liquids go above the boiling point they (by definition) turn to gas. As gas accumulates in the vessel’s head space pressure builds. If the gas is not used as product the pressure will build to the point that the vessel vents off. Excessive venting is an indication that a vessel is not performing properly and might have a weakened vacuum allowing greater heat incursion.

The release of molecules through venting reduces the weight of the vessel. So- the easiest way to measure NER is by weighing the vessel over a period of several days. Conducting a fully controlled NER is difficult to accomplish in most production environments as it requires fully stabilizing the liquid, not moving the vessel during testing, and taking readings at nearly the same time over a period of days along with having a scale capable of measuring nearly 1000 that is not needed for other purposes.

Tomorrow, we’ll detail steps for a full NER test. In the meantime, it is important to pressurize your vessel and check all plumbing and fitting connections for leaks with an approved solution prior to starting the NER. You should also use the leak test on the outlet of all connections to assure that none of the valves are leaking.

Cryogenic Applications: Liquid Nitrogen in Bottling

Most projections for the cryogenics gases industry project a steady rate of growth over the coming years. This is due in large part to the constant flow of new applications for gases (innovation) and increased availability of gases in more remote parts of the world. Two recent Saudi visitors cited the shortage of air separation units in the Mid-East and the consequent inability to provide enough liquid oxygen, nitrogen or argon to meet existing demand. Absent supply there is no reason to innovate.

Once supply does become available, though, there is room for innovation.

One of my first cryogenic gas industry exposures came through attendance at food and beverage production convention in New Orleans. There were 3 or 4 exhibitors with liquid nitrogen injection systems ranging from basic continuous flow to ultra-sophisticated drop systems that could pop one or two drops as needed right into individual bottles regardless of spacing or flow. The nitrogen injected serves two purposes. First, the nitrogen gas provides and inert blanket which protects the product from oxygen. This keeps it fresher, safer and tastier longer. Quick capping traps the expanding gas so the bottle is now pressurized. This increases the strength of the plastic bottle or can allowing the use of thinner materials and increasing the ability to stack.

"Fixed"- What's in a word?

It is said that a key to gaining knowledge is learning the right words. Working with cryogenic tanks has proven a challenge mostly due to the English language and the use of multiple words for a single item as well as the use of a single word for many items.

For example, a client might call asking for “a Safety.” Seems easy, right?

So, you sent them a “Safety.” Did you send them a relief, a burst disk, a rupture disk, a head safety, or a vacuum rupture disk? Was it an in-line device or open to atmosphere? What pressure was it set at and how did you know the right pressure? Did you simply look at the pressure of the device being replaced and put on the same thing?

I ask because a client called one day and somewhat urgently wanted to know if we could replace one of the safeties on their truck mounted liquid oxygen delivery vessel right away. Their safety was apparently “broken” and the vessel wasn’t holding pressure so they couldn’t do their medical oxygen deliveries. It was close to closing time and they were several hours away so we gave them an after-hours number to call when they got to the shop so we could meet them. Paraphrasing Jimmy Buffet, the phone never rang so we knew it was them.

Several days later the wayward van arrived with the driver all calm and composed. When asked how they survived without the safety being repaired the driver responded:

“Oh, we’ve been OK. It turns out that one of the guys in the shop has a lot of cryogenics experience and he ‘fixed’ it.” This gave rise to that little sick feeling that the wrong words can generate. Predictably, the “experienced” guy in the shop had removed a blown burst disk safety and installed plug in its place to “fix” it.

See the post dated 1/19/09 if you’d like a better idea of what this “fix” might have meant to the driver. http://cryonews.blogspot.com/2009/01/improperly-decommissioned-liquid.html

Snow Job

If you weren’t fortunate enough to watch Sunday Morning on CBS today you missed a fascinating story about Kenneth G. Libbrecht who studies snowflakes and does snowflake art at CalTech. He has designed a special magnifying camera for photographing the crystals and his photos were even used for USPS holiday stamps. He is now working to grow his own flakes in the controlled California lab environment…… hence the link to cryogenics.

His website http://www.snowcrystals.com/ is pretty fascinating. Of course, you might note that this review comes from a guy who drives from Houston to Las Vegas never bored by the scenery.