Aluminum Extrusion: Staying Cool with Nitrogen

Aluminum is a highly malleable material, which is readily shaped for any number of purposes. The aluminum extrusion process is key to shaping aluminum, and it must be completed in an inert environment to reduce the formation of oxides. Learn why this is important and how facilities can reduce the risks of health hazards in an inert environment. 

How Aluminum Extrusion Works

Billets of aluminum are first heated to above 800 degrees Fahrenheit to become malleable, then coated with a lubricant so the molten metal will not stick to the extruding ram. 

The ram presses the aluminum billet through a die, which is cast in a given shape. As the aluminum passes through the die, liquid nitrogen flows over the metal to prevent oxides from adhering to the aluminum. This also extends the lifespan of the die by cooling it. In some operations, nitrogen gas is used instead of liquid. While the overall purpose is the same -- to keep out oxides, which can cause the extruded aluminum to crack -- the gas does not cool the die. 

The shaped aluminum passes through the die, then exits the press where its temperature is taken. Temperature records help maintain press speeds, for plant efficiency. The extruded aluminum pieces are then transferred to a leadout table and a puller, where the metal is cooled using fans. Some mixtures of aluminum are cooled with water as well as air. 

The cooled and cut aluminum is then stretched via a stretcher, a step that increases the hardness and strength of the finished piece. Finally, extruded aluminum pieces are cut for precision and aged under controlled temperatures via heat treatment. 

The entire process resembles a play-doh modeling kit, where the dough is squeezed through a press and comes out in a tube or a star shape, for instance. 

Extruded aluminum pieces are used in a variety of industries, including railway cars, lightweight automobiles, bridge decking, solar panels, and coaxial cables. 

Whether liquid or gaseous nitrogen is used, there is a risk of a nitrogen leak causing an oxygen deficient atmosphere. Nitrogen is naturally heavier than oxygen, so it displaces the oxygen molecules in the atmosphere. Since nitrogen has no color, odor, or scent, employees are unable to tell there's a leak. A leak poses health hazards in addition to work disruption and revenue losses. Fortunately, there's an easy way to protect facility staff. 

Why Oxygen Sensors Should Be Used With Aluminum Extrusion 

When nitrogen displaces oxygen, oxygen levels start to fall unbeknownst to anyone present. Eventually, oxygen levels will grow dangerously low. In an oxygen deficient environment, employees may start to feel dizzy or confused. Some may sweat, start to cough, or experience rapid breathing and increased heart rate. Death via asphyxiation is a real risk. 

An oxygen sensor provides assurance that there is no leak, since it tracks levels of oxygen in the room 24/7. As long as oxygen levels are above the OSHA threshold of 19.5, the monitor will be silent. If liquid or gas nitrogen starts to leak, leading oxygen levels to fall, the monitor will sound an air horn and flash lights. Staff will understand there is a problem and will have time to evacuate to safety. Staff can also check the monitor face at any time to see oxygen levels at a glance. 

PureAire offers oxygen monitors that feature zirconium sensors, which last long and withstand shifts in barometric pressure and temperature. These monitors can operate for over 10 years with no annual maintenance or calibration. PureAire's monitors work in temperatures from -40 Celsius to 55 Celsius and even function in confined spaces, such as basements or freezers.  Learn more about PureAire's products at www.pureairemonitoring.com. 

Taste the Difference with Nitrogen Packed Coffee Grounds

When it comes to flavor, coffee purists prefer whole beans, which retain their flavors longer than ground coffee. Yet there's no denying the convenience factor of ground coffee, which is why it's so popular in offices. Ground coffee has a short shelf life -- hence the push to use airtight containers, which keep the flavors in the coffee -- and off flavors may develop if the coffee grounds are left on the shelf too long. Some coffee companies are trying a new trick to add shelf stability to their ground coffee: a nitrogen flush.

How Nitrogen Flushing Preserves Coffee Grounds

Oxygen is the enemy of ground coffee: When coffee grounds come into contact with oxygen, they go stale faster. This is why coffee grounds are sold in vacuum-sealed containers, and why consumers are encouraged to use airtight containers. For best flavor, coffee beans should also be stored in dark containers (so light does not pass through).

Some amount of oxygen is produced (in the form of CO₂) as the ground coffee degasses, a naturally occurring process. To release these gases and preserve coffee flavor, many coffee bags contain a one-way valve. Oxygen escapes through the valve, but cannot come back into the bag.

Some coffee companies are taking it one step further by flushing the bag with nitrogen gas during the coffee packaging process, which ensures that no oxygen is in the bag with the coffee where it would cause spoilage. Nitrogen gas is heavier than oxygen, so when it is pushed into the empty coffee bag, it displaces oxygen. The bag is then filled with coffee grounds and sealed with no ambient oxygen in the sack. This preserves coffee flavor.

Since nitrogen gas has no color or odor, it does not affect the taste of the coffee. What consumers get, months later, is grounds that are as fresh as they were the day the coffee was roasted and ground.

While this is beneficial for the consumer, nitrogen flushing may prevent problems at the packaging plant. Just as nitrogen gas flushes oxygen out of the bag, so can it displace oxygen from the room. If a leak were to occur, employees would not be able to tell (remember, the gas has no smell, odor, or color). A leak could push so much oxygen out of the air that staff could suffer respiratory problems, death via asphyxiation being the worst-case scenario.

How an Oxygen Sensor Can Protect Your Employees

Since nitrogen displaces oxygen, it's easy to detect a leak by tracking the levels of oxygen in the room. Oxygen sensors -- also known as oxygen deficiency monitors -- continually monitor oxygen levels. As long as the room air remains stable, there's no leak. When the levels of oxygen in the air fall to the OSHA threshold of 19.5 percent, where a health threat is imminent, the sensor will go off. Employees will see a flashing light and hear a loud alarm that warns of the low levels of oxygen. Staff can exit the packaging facility without suffering adverse health effects; they also enjoy peace of mind every day by checking the O₂ monitor.

PureAire supplies coffee manufacturers with oxygen sensors that help them offer a higher-quality product without placing workers at risk. PureAire's oxygen deficiency monitor requires no maintenance and calibration once installed, thanks to a hardy zirconium sensor. Once installed, the O₂ monitor will provide accurate readouts and leak detection for 10 or more years. PureAire's oxygen deficiency monitors function properly despite changes to barometric pressure, thunderstorms, and other weather events. Suitable for use in freezers, basements, and other confined spaces, PureAire's monitors perform in temperatures from 55 Celsius to -40 Celsius.

To protect worker safety, an oxygen monitor should be used wherever nitrogen gas is stored or used. Learn more about PureAire's products at www.pureairemonitoring.com.

What is a -150C Nitrogen freezer and who uses them?

A -150 C freezer, also known as a nitrogen freezer, is used in cryo preservation. While you might think of Ted Williams being frozen on ice for a future in which he can be brought back to life, the cryo preservation method can be used to keep any type of cell alive in a suspended state. Learn how nitrogen freezers are used and how PureAire can keep your facility safe. 

Who Uses Nitrogen Freezers? 

Nitrogen freezers use liquid nitrogen to freeze biological material in extremely cold temperatures. While they are known as -150 C freezers, they actually run closer to -200 C. When living cells are stored at such low temperatures, they go to sleep rather than die. Decades or even centuries later, the frozen cells can be safely thawed with no loss of life or degradation of DNA due to their long storage. 

Compared with other methods of cryo preserving materials, a liquid nitrogen freezer offers the most stable freezing environment using ultra-low temperatures. An electric freezer is incapable of maintaining temperatures below -135 C.  

Environmental researchers are interested in cryo preservation to preserve the last stock of endangered species. Rather than lose, say, the critically endangered black rhino species, the rhino's cells can be cryogenically frozen for the future. Coral reefs are also considered desirable candidates for cryo preservation due to their high rates of die-off from ocean acidity. 

Animal breeders are interested in cryo preservation to keep a desired bloodline alive, and fertility specialists see the potential for helping women delay childbirth through cryogenic preservation of fertilized embryos or eggs. 

The cryo preservation industry is not without its challenges. To ensure the viability of the frozen material, the cells must be slowly brought to the -150 C temperature and thawed in the same manner. If the temperature drops too quickly per minute, the cell membrane could rupture, causing cell death. 

Any time liquid nitrogen is used, there is a risk of oxygen displacement should the nitrogen storage tank leak or spill. Nitrogen gas has no color or odor, so employees would not notice that a leak had occurred. 

As nitrogen leaks into the atmosphere, it displaces oxygen. Levels can fall so low that the ambient air will not have enough oxygen for safe respiration. In an oxygen deficient environment, workers can experience respiratory distress, cognitive deficiencies, and death via asphyxiation simply by taking a few breaths in an oxygen deficient environment. 

Any facility that relies on nitrogen freezers to preserve biological material must take safeguards to detect and mitigate nitrogen leaks. One simple, effective solution is an oxygen monitor, such as that offered by PureAire.

How PureAire Can Help 

An oxygen monitor measures the levels of oxygen in the room. As long as there is enough oxygen, the monitor remains silent yet alert. If a spill occurs and levels fall close to the OSHA threshold, the alarm flashes a light and sounds an alarm to notify all personnel there is a leak. Employees can then leave the room before they are harmed by the oxygen deficient air. 

PureAire's oxygen monitor features a robust zirconium sensor, which can take accurate reading without maintenance for 10 or more years. The monitor provides steady readings when barometric pressure changes or thunderstorms occur. The O₂ monitor functions accurately in temperature extremes, and is suitable for use in cryogenic facilities and freezers.

If you're interested in a reliable oxygen monitor that's accurate, cost-effective, and fuss-free, you may want to partner with PureAire. Learn more at www.pureairemonitoring.com.

Nitrogen Tank or Cryogenic Dewar? Not Sure Where they are Installed? Here's the List!

Liquid nitrogen is used in a broad range of industries, from steelmaking and pharmaceutical to health care and ceramics. The inert gas is also used in laboratories, breweries, fine cooking, and more. Wherever liquid nitrogen is used, it must be stored securely so as not to mingle with air. Learn why nitrogen must be so carefully contained and where and how N₂ gas is stored. 

Bulk Nitrogen Tank Storage 

Liquid nitrogen is stored in a bulk nitrogen tank, also known as a nitrogen dewar. Nitrogen dewars exist wherever nitrogen is used, including in: 

• Labs
• Research universities 
• Restaurants, bars, and hotels 
• Freezers
• Hospitals 
• Flash freezing facilities
• Food processing facilities
• Cryotherapy facilities 
• Manufacturing plants 

The nitrogen dewar features a vacuum stopper, which protects the substance inside and prevents the nitrogen from boiling off. Dewars must have pressure release valves to prevent a bulk nitrogen tank explosion, which can occur when pressure builds up inside the tank. Since liquid nitrogen vaporizes at room temperature, it's critical that the tank stay sealed at all times.

Nitrogen and other insert gases, including argon, displace air when they are released into the environment. As oxygen is displaced, the air becomes oxygen deficient. Breathing oxygen deficient air causes respiratory distress and death via asphyxiation. Since nitrogen is colorless and odorless, there is no way to tell that a leak occurs unless you use an oxygen monitor, which samples oxygen levels. 

Given the risks posed by the material, bulk nitrogen tanks must be stored and transported safely and securely. Workers must bleed out pressure before transporting the tanks, for example, to reduce the risk of incident during transport. 

A robust ventilation system should be installed where the nitrogen is kept, so escaped nitrogen can be vented away, and fresh air should be circulated into the storage room several times per hour. 

Other safety measures include checking that fittings are appropriate, wearing gloves to prevent the nitrogen from burning the skin, and never filling dewars more than 80 percent full. 

While liquid nitrogen can be transferred from the bulk nitrogen tank into a smaller tank for small scale use, it must only be transferred into approved container. If you use the wrong container, it could shatter, leaking nitrogen into the air and decreasing available oxygen. 

Wherever nitrogen is stored or used, signs warning of the risks associated with the material should be posted as a warning to employees. When working with nitrogen, staff should wear eye protection, cryogenic gloves, and other safety equipment. 

Anyone who handles or works with the gas should be trained in safe use, storage, and handling of bulk nitrogen tanks as well. The valves, gauges, and other components of the nitrogen storage tank should be inspected regularly for safety, and replaced whenever you notice wear and tear. 

Why You Need an Oxygen Monitor Where Nitrogen is Stored

By placing an oxygen monitor wherever nitrogen is used, you can protect worker safety and prevent injury or fatality onsite. Oxygen monitors continually sample oxygen levels in the room, making sure that oxygen falls within acceptable levels. Should nitrogen gas leak from the dewar, ambient oxygen levels will start to tumble as the air is displaced by nitrogen. 

When oxygen levels fall to the threshold set by OSHA, which is 19.5 percent, the oxygen deficiency monitor will sound and flash alarms to notify workers onsite. Staff can exit the room before they begin to experience the adverse effects of being in an oxygen deficient atmosphere, then call 911 so emergency personnel can respond to the threat. 

PureAire offers a robust oxygen deficiency monitor capable of withstanding low temperatures of -40 Celsius. Once installed, the oxygen monitor works as intended for 10+ years with no annual maintenance or calibration. An ultra-loud alarm is audible throughout the premises, while a flashing light provides a secondary alert for employees. The unit easily mounts on the wall with brackets and comes with a 3-year warranty. Learn more about oxygen monitors from PureAire at www.pureairemonitoring.com. 

               

Oxygen Monitors now Required for Nitrogen, Argon, Helium, and CO2 use in Denver

Oxygen Monitors now Required for Nitrogen, Argon, Helium, and CO2 use in Denver

The Colorado city of Denver recently passed a new law that requires facilities that use insert gas to install oxygen deficiency monitors wherever these gases are used in excess of 100 pounds. Learn what the new law requires from businesses and how an oxygen sensor protects your employees, your business, and your peace of mind. 

What Denver's New Law Requires 

The law specifically applies to Colorado commercial, industrial, or manufacturing facilities that use inert gases, including nitrogen, argon, carbon dioxide, and helium. Facilities covered by the new law include water treatment plants, laboratories, and food processing plants. 

Fire suppression systems and medical gas systems are not covered by the Denver law. 

Under the new law: 

• Inert gas storage tanks must be placed in approved locations, whether stored inside or outside of the building 
• Storage containers must be secured to prevent tip-overs
• All valves and tubing used with the gas system must meet applicable standards
• Gases must vent outside the building
• All areas where gas is used must either have an oxygen deficiency monitor or continuous ventilation system, which keeps the oxygen levels in the room steady 
• Oxygen alarms should be visually inspected daily by trained staff members
•  Storage tanks, piping, and other parts of the system must be checked on a monthly basis 
• Tests of the system must be conducted regularly with either air or an inert gas

The Denver law sets out regulations for the type of oxygen deficiency monitor, plus where and how to use them. Acceptable monitors must be installed in any location where an inert gas leak could result in an oxygen deficient environment where public health could be at stake. 

Oxygen detectors must be on an approved device list and directly connected to the electrical supply and fire alarm system for the site. The oxygen detectors must be permanently mounted to the wall at a height which is consistent with the given gas's vapor density, so they can work properly. The devices must be located within their specified ranges of operation, in order to ensure the monitors can work as intended. 

The law prohibits self-zeroing or auto calibrating devices, unless they can be spanned or zeroed to check that the oxygen monitor is working as it should be. All installed oxygen monitors must be calibrated regularly to ensure safe and reliable operation. 

Alongside mounted alarms, companies must place signage that notifies employees of the oxygen monitor and gives instructions for what to do in the event of an alarm. Typical instructions tell staff to leave the building and call 911 if the alarm is going off. 

Signs notifying employees of the risk for oxygen deficiency must be posted anywhere inert gas is stored or used.

To further protect employees, the Denver law mandates that gas be transported, filled, or moved only by qualified individuals who follow protocol. All equipment, including piping systems, must be inspected for competency and the organization must maintain records for a period of three years. 

Why an Oxygen Monitor is a Practical Suggestion 

Oxygen deficient environments occur when an inert gas, such as helium, nitrogen, or argon, escapes into the environment and begins to displace oxygen. Since these gases have no odor or color, there is no way that staff working in the room can tell something is leaking. As the oxygen levels fall, employees can experience confusion and respiratory distress, resulting in death by asphyxiation. 

An oxygen monitor tracks ambient levels of oxygen and sets off an alarm when oxygen levels fall below the safe threshold, thus protecting employee safety. Since employees can both hear and see the alarm, they will know there is a problem even if they are operating loud equipment that overrides the noise of the sensor. 

Oxygen monitors are simple solutions to pressing problems faced by organizations that rely on inert gases and want to mitigate their risk. 

PureAire's oxygen sensors are cost-efficient and high quality. They are designed with a zirconium sensor, which is capable of lasting for as long as 10 years. PureAire's oxygen sensor is accurate in diverse environments, from storage freezers to basements. The sensor functions between -40 and 55 C. While PureAire's oxygen monitors do not need to be calibrated, they are capable of calibration, thus eligible for use in Denver. 

PureAire's monitors need little maintenance to work reliably once they are installed using the included wall-mounting brackets, and they are not affected by changes in the barometric pressure, a known problem with other types of oxygen sensors. PureAire's products can be set to measure oxygen levels of either 18 percent or 19.5 percent (which is the OSHA action level), to comply with standards. 

To learn more about oxygen monitors from PureAire, and view specifications, go to www.pureairemonitoring.com.