This time of the year it is not uncommon to feel a slight shock after walking across a carpeted surface and touching a door knob. This little “jolt” is a result of fast-moving electrons leaping from your body to the door knob, or vice versa. As your feet shuffle across the surface of a rug or carpet, your body will either gain or lose electrons. Touching a conductive surface then causes these electrons to leap from one place to another. This is known as static electricity.
If you notice, this happens to occur much more often during colder winter months (if you’re one of those fortunate people to live outside of this sensation we call “cold” please don’t rub it in!). The reason that you experience static shocks more frequently during winter is due to the relative humidity. At colder temperatures, air does not hold as much moisture as it does when it’s warm and moisture helps to conduct electrical charges. Even though you’re heating your house to a similar temperature, the air that is being drawn into your home and heated is still the dry cold air containing less moisture.
The amount of moisture in the air is expressed as relative humidity. This value is given as a percentage of water vapor in the air, compared to how much it could hold at that temperature. In conditions of lower relative humidity, static charges build up much easier. When the relative humidity is high, there’s a higher concentration of water molecules present in the air. These water molecules “coat” the surface of the material, allowing electrons to move more freely and form a layer over the material. This layer of water molecules acts like a lubricant, reducing the forces that cause static to generate. This is why static is much more noticeable during the winter months.
There are many applications that static only appears when the seasonal climate changes. Issues can manifest in the form of nuisance shocks to operators, materials jamming, tearing or curling, product sticking to itself and to rollers, dust clinging to product, and many more. If static is causing problems in your processes, we have a wide variety of Static Eliminators available from stock. Don’t just deal with the problems until humid conditions return, get a permanent solution in place that’ll neutralize the static and eliminate a troublesome application. Contact an EXAIR Application Engineer today and we’ll help to diagnose the root cause of the problem and recommend the best solution.
Air… We all breathe it, we live in it, we even compress it to use it as a utility. What is it though? Well, read through the next to learn some valuable points that aren’t easy to see with your eyes, just like air molecules.
Air is mostly a gas.
Comprised of roughly 78% Nitrogen and 21% Oxygen. Air also contains a lot of other gases in minute amounts. Those gases include carbon dioxide, neon, and hydrogen.
Air is more than just gas.
While the vast majority is gas, air also holds lots of microscopic particulate.
These range from pollen, soot, dust, salt, and debris.
All of these items that are not Nitrogen or Oxygen contribute to pollution.
Not all the Carbon Dioxide in the air is bad.
Carbon Dioxide as mentioned above is what humans and most animals exhale when they breathe. This gas is taken in by plants and vegetation to convert their off gas which is oxygen.
Think back to elementary school now. Remember photosynthesis?
If you don’t remember that, maybe you remember Billy Madison, “Chlorophyll, more like Bore-a-fil.”
Carbon dioxide is however one of the leading causes of global warming.
Air holds water.
That’s right, high quality H2O gets suspended within the air molecules causing humidity. This humidity ultimately reaches a point where the air can simply not hold anymore and it starts to rain. The lack of humidity in the air leads to static, while lots of moisture in the air when it gets compressed causes moisture in compressed air systems.
Air changes relative to altitude.
Air all pushes down on the Earth’s surface. This is known as atmospheric pressure.
The closer you are to sea level the higher the level of pressure because the air molecules are more densely placed.
The higher you are from sea level the lower the density of air molecules. This causes the pressure to be less. This is also why people say the air is getting a little thin.
Hopefully this helps to better explain what air is and give some insight into the gas that is being compressed by an air compressor and then turned into a working utility within a production environment. If you would like to discuss how any of these items effects the compressed air quality within a facility please reach out to any Application Engineer at EXAIR.
To begin with all EXAIR ASN’s are made from SS for durability and liquid compatibility. As its name implies it creates a flat fan pattern that exit’s the nozzle perpendicular to the air & liquid inlets as shown above. This unique design lends itself nicely to applications with space constraints. The AD1010SS is the ideal choice for coating the inside of enclosures or ductwork. It is compatible with liquids up to 300 centipoise and the air and liquid are mixed in the air cap. The AD1010SS is designed for pressure fed applications not requiring independent air and liquid control. What is meant by that statement is that if you vary either the air or liquid pressures you change the spray pattern and volume. See the chart below for clarification on pressures, volumes and spray patterns.
Next we will look at EXAIR model AT1010SS internal mix 360° hollow circular pattern ASN.
The AT1010SS internal mix 360° nozzle is designed for applications where the spray pattern must be oriented away from the nozzle in all directions. 360° nozzles are ideal where a smooth, even coating is needed on the ID of a pipe or similar ductwork. It is compatible with liquids up to 300 centipoise and the air and liquid are mixed in the air cap. The AT1010SS is designed for pressure fed applications not requiring independent air and liquid control. As above if you vary either the air or liquid pressures you change the spray pattern and volume. See the chart below for clarification on pressures, volumes and spray patterns. They also work great for operations where a mist over a broad area is needed, such as dust suppression, humidification and cooling. See the chart below for clarification on pressures, volumes and spray patterns.
We’ve seen in recent blogs that Compressed Air Dryers are an important part of a compressed air system, to remove water and moisture to prevent condensation further downstream in the system. Moisture laden compressed air can cause issues such as increased wear of moving parts due to lubrication removal, formation of rust in piping and equipment, quality defects in painting processes, and frozen pipes in colder climates. The three main types of dryers are – Refrigerant, Desiccant, and Membrane. For this blog, we will review the basics of the Refrigerant type of dryer.
All atmospheric air that a compressed air system takes in contains water vapor, which is naturally present in the air. At 75°F and 75% relative humidity, 20 gallons of water will enter a typical 25 hp compressor in a 24 hour period of operation. When the the air is compressed, the water becomes concentrated and because the air is heated due to the compression, the water remains in vapor form. Warmer air is able to hold more water vapor, and generally an increase in temperature of 20°F results in a doubling of amount of moisture the air can hold. The problem is that further downstream in the system, the air cools, and the vapor begins to condense into water droplets. To avoid this issue, a dryer is used.
Refrigerant Type dryers cool the air to remove the condensed moisture and then the air is reheated and discharged. When the air leaves the compressor aftercooler and moisture separator (which removes the initial condensed moisture) the air is typically saturated, meaning it cannot hold anymore water vapor. Any further cooling of the air will cause the moisture to condense and drop out. The Refrigerant drying process is to cool the air to 35-40°F and then remove the condensed moisture. The air is then reheated via an air to air heat exchanger (which utilizes the heat of the incoming compressed air) and then discharged. The dewpoint of the air is 35-40°F which is sufficient for most general industrial plant air applications. As long as the compressed air stays above the 35-40°F temperature, no further condensation will occur.
The typical advantages of Refrigerated Dryers are-
– Low initial capital cost
– Relatively low operating cost
– Low maintenance costs
If you have questions about getting the most from your compressed air system, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.
Fog. Nobody likes driving in it. It’s downright perilous to sailing vessels on the open water, but especially those near the shore, or other watercraft. Flights get delayed or cancelled, stranding travelers in airport terminals far from home, and keeping many from pressing matters that necessitated the speed of an airline flight in the first place. Oh, and it’s ALWAYS where the bad guy is hiding in the movies. You can tell by the ominous low-string music that starts playing right before things get real nefarious.
You know who LIKES fog, though? Greenhouse operators. Their plants get plenty of water to sustain their growth from the well-irrigated soil, but the leaves & petals can wither and get discolored if the humidity isn’t kept at a high level.
The same is true for the parts of a greenhouse that folks don’t see when they’re selecting the annuals to plant on the next nice spring weekend (which we should be coming up on quite soon here!) – like the seed germination chambers. I had the pleasure of helping a greenhouse operator recently, who needed to replace some old, and malfunctioning, nozzles in one of their germination chambers. They were interested in the extremely fine mist that our Atomizing Spray Nozzles produce. After some experimentation with a couple of different flow rates & patterns, they determined that the Model AW1020SS (Wide Angle Round Pattern, Internal Mix) Atomizing Spray Nozzles provided optimal results.
As the fogging systems in their other chambers start to fail, they’ve been replacing them with the AW1020SS’. We shipped them two earlier this week.
Recently, I was working with a customer that has purchased several of the EXAIR Atomizing Spray Nozzles, specifically the model Aw5020SS. The customer had another project coming up and needed two more nozzles. I inquired about the application and we discussed at length the way the nozzles are being used.
When a concrete road is being poured, several sample forms are poured during the process. The local Department of Transportation takes the samples and cures them in a wet room for 30 days, and then performs tensile testing, to confirm the concrete meets the strength requirements. The wet room must be kept at 23°C (73.4°F) and 100% Humidity during this time frame. The EXAIR model AW5020SS Atomizing Nozzles are used to provide the moisture that ensures the room humidity conditions are met and maintained. Because the droplets are very fine, the effect of a fog is achieved, with the water droplets suspended in the air, keeping the humidity at 100%.
Atomizing spray nozzles are capable of producing very fine droplet sizes. A typical rain drop is 6000 microns in diameter, standard liquid nozzles produce droplets ranging from 300-4000 microns. The EXAIR Atomizing Nozzles produce droplets from 20-100 microns!
Droplet sizes can be adjusted by varying either the liquid pressure or air pressure. Increasing the air or decreasing the liquid pressure will generally produce a smaller droplet size.
EXAIR manufactures (3) types of Atomizing Nozzles – Internal Mix, External Mix, and Siphon Fed, in both 1/4 NPT and 1/2 NPT sizes. Maximum liquid viscosity is 800 cP. Flow rates range from 0.6 GPH up to 303 GPH, so we’ll be able to find one that meets your flow requirements.
To discuss your application and how an EXAIR Atomizing Nozzle can benefit your process, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.
The ETC Dual Cabinet Cooler Systems work in conjunction with EXAIR’s UL listed Cabinet Cooler Systems which provide cooling for your electrical enclosures without the use of refrigerant based coolants or fans. The Cabinet Cooler Systems utilize a compressed air driven Vortex Tube which uses compressed air. This cold compressed air is exhausted into the enclosure which results in a cool working environment for your electronics. Warm air from inside the enclosure is vented safely back out of the cabinet through built in exhausts and the compressed air is only utilized when the internal air temperature reaches the digitally set temperature on the ETC.
Another added benefit of the ETC on the Cabinet Cooler system is the real time readout of the internal air temperature of your enclosures. This is on top of the push button set point which will give you a +/-2°F ambient temperature inside of your enclosure.
The ETC Dual Cabinet Cooler Systems are designed for larger heat loads ranging from 3,400 BTU/hr. to 5,600 BTU/hr. The units are available in NEMA 12, NEMA 4, and NEMA 4X ratings. This means whether you are in a fairly clean environment or a dirty, hot, muggy environment, EXAIR has you covered.