The National Electrical Code, or NEC, classifies hazardous areas into three different categories; Class I, Class II, and Class III. To use equipment in or around these types of areas, caution has to be taken… More
Henri Coanda was a Romanian aeronautical engineer best known for his work on the fluid dynamic principle with his namesake, the Coanda effect. Before this, Henri patented what he labeled as a jet engine.
Henri’s patent (French patent No. 416,54, dated October 22, 1910) gives more information into how he envisioned the motor working. When air entered the front, it passed through different cavities that caused the air stream to first contract and then expand. In Henri’s opinion this contraction and expansion converted the air’s kinetic energy into potential energy. The air ultimately was channeled to a diffuser where it was discharged.
Henri stated that the efficiency of this engine could be improved by heating the air in the cavities, Henri’s logic was that this would increase the pressure of the air passing through.
What is obviously lacking in the patent (including identical ones taken out in England and the United States) is any mention of injecting fuel, which in a true jet engine would combust with the incoming air. Judging only by Henri’s patent, it was little more than a large ducted fan and it could not have flown. Throughout Henri’s career he changed his story many times on whether this plane actually flew or not.
Not to cast too much shade on Henri’s accomplishments he did discover the Coanda effect. The Coanda effect states that a fluid will adhere to the surface of a curved shape that it is flowing over. One might think that a stream of fluid would continue in a straight line as it flows over a surface, however the opposite is true. A moving stream of fluid will follow the curvature of the surface it is flowing over and not continue in a straight line. This effect is what causes an airplane wing to produce lift, and enhance lift when the ailerons are extended while at lower air speeds such as occurs during takeoff and landing.
EXAIR uses the Coanda effect to offer you highly engineered, intelligent and very efficient compressed air products. Our designs take a small amount of compressed air and actually entrain the surrounding ambient air with the high velocity exiting compressed air stream to amplify the volume of air hitting a surface.
When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call. We would enjoy hearing from you.
The video below provides details on the simple conversion to the new Gen4 style Super Ion Air Knife from the previous style or the addition of a Gen4 Ionizing Bar to an existing Super Air Knife to add static elimination to an existing blow off.
If you have questions about the Gen4 Super Ion Air Knife or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
What is an air compressor? This may seem like a simple question, but it is the heartbeat for most industries. So, let’s dive into the requirements, myths, and types of air compressors that are commonly used. Like the name states, air compressors are designed to compress air. Unlike liquid, air is compressible which means that it can be “squished” into a smaller volume by pressure. With this stored energy, it can do work for your pneumatic system.
There are two types of air compressors, positive displacement and dynamic. The core component for most air compressors is an electric motor that spins a shaft. Positive displacement uses the energy from the motor and the shaft to change volume in an area, like a piston in a reciprocating air compressor or like rotors in a rotary air compressor. The dynamic types use the energy from the motor and the shaft to create a velocity energy with an impeller. (You can read more about types of air compressors HERE).
Compressed air is a clean utility that is used in many different ways, and it is much safer than electrical or hydraulic systems. But most people think that compressed air is free, and it is most certainly not. Because of the expense, compressed air is considered to be a fourth utility in manufacturing plants. For an electrical motor to reduce a volume of air by compressing it. It takes roughly 1 horsepower (746 watts) of power to compress 4 cubic feet (113L) of air every minute to 125 PSI (8.5 bar). With almost every manufacturing plant in the world utilizing air compressors much larger than 1 horsepower, the amount of energy needed to compress air is extraordinary.
Let’s determine the energy cost to operate an air compressor to make compressed air by Equation 1:
Cost = hp * 0.746 * hours * rate / (motor efficiency)
Cost – US$
hp – horsepower of motor
0.746 – conversion KW/hp
hours – running time
rate – cost for electricity, US$/KWh
motor efficiency – average for an electric motor is 95%.
As an example, a manufacturing plant operates a 100 HP air compressor in their facility. The cycle time for the air compressor is roughly 60%. To calculate the hours of running time per year, I used 250 days/year at 16 hours/day for shifts. So operating hours equal 250 * 16 * 0.60 = 2,400 hours per year. The electrical rate at this facility is $0.10/KWh. With these factors, the annual cost to operate the air compressor can be calculated by Equation 1:
Cost = 100hp * 0.746 KW/hp * 2,400hr * $0.10/KWh / 0.95 = $18,846 per year in just electrical costs.
So, what is an air compressor? The answer is an expensive system to compress air to operate pneumatic systems. So, efficiency in using compressed air is very important. EXAIR has been manufacturing Intelligent Compressed Air Products since 1983. If you need alternative ways to save money when you are using your air compressor, an Application Engineer at EXAIR will be happy to help you.
EXAIR is always focused on releasing new products and improving on existing product lines, and 2018 has been no different! Earlier on this year we introduced the New Super Air Scraper as an accessory to our 2” Flat Nozzles and Safety Air Guns. Just last month, EXAIR has also introduced a new line of products to the Cabinet Cooler family: The Hazardous Location Cabinet Cooler.
EXAIR’s Hazardous Location Cabinet Coolers are engineered for use with purged (not included) electrical enclosures. The HazLoc Cabinet Coolers are not purged and pressurized control systems and should not be relied upon nor used in place of a purged and pressurized controller. They are meant for use in conjunction with a purged and pressurized control system. These systems have been approved and tested by UL for use in the following areas:
Class I Div 1&2 – Groups A, B, C, and D
- Class I Areas refer to the presence of flammable gases or vapors in quantities sufficient to produce explosive or ignitable mixtures. Class I Div 1 will have ignitable concentrations of flammable gases present during the course of normal operations. This is level of approval is one that differentiates the EXAIR Hazardous Location Cabinet Coolers from much of the competition. Class 1 Div 2 areas will have flammable gasses or vapors present only in the event of an accident or during unusual operating conditions.
Class II Div 1&2 – Groups E, F, and G
- Class II areas are locations in which combustible dust may exist. The end user shall avoid installation of the device in a Class II environment where dust may be readily disturbed from the exhausts of the Hazardous Location Cabinet Cooler. Any dust formed in the vicinity of the cooler must be cleaned regularly.
- Class III areas are locations that will have ignitable fibers or flyings present. This is common within the textile industry.
The Cabinet Cooler also carries a temperature rating of T3C, meaning it cannot be installed near any materials that could auto-ignite at temperatures in excess of 320°F. For a comprehensive list and description of all of the various Classified areas, check out the UL website.
The Hazardous Location Cabinet Cooler is available in (8) different cooling capacities ranging from 1,000 Btu/hr – 5,600 Btu/hr. The Cabinet Cooler is the best solution for protecting your sensitive electronics from heat, dirt, and moisture. With Nema 4/4X systems available, the Hazardous Location Cabinet Coolers will keep the cabinet cool without compromising the integrity of the enclosure.
If you’ve got an electrical cabinet installed within a hazardous location, fill out the Cabinet Cooler Sizing Guide and allow an EXAIR Application Engineer to determine the most suitable model for you.
I once worked in an equipment repair shop with a small and simple compressed air system…just a 5HP single acting piston compressor that sat atop a 50 gallon tank, in the corner by “The Big Truck”. The majority of our work was field service, and management was big on maintaining our service trucks, so we checked tire pressures every Monday morning as we rolled out, and kept a tire chuck handy to ensure proper inflation. It was also used to supply a couple of air guns that were used at our drill press and soldering/assembly station. One morning, I noticed the air compressor was running when I arrived…I thought it was odd, because I knew for a fact it hadn’t been used in at least 16 hours, but that compressed air went someplace, right? We had a leak. Well, at least one.
This was mid-December, and the week between Christmas and New Year’s Day was characteristically slow, and typically devoted to a thorough shop cleaning. We also took the opportunity to get some bottles of soapy water and check for leaks at the handful of pipe fittings that comprised the system…for the uninitiated, if you have a leaky fitting, the escaping air blows bubbles in the soapy water (a cheap, messy way in other words). We found some bubbling, undid those fittings, cleaned them, and applied fresh pipe thread sealant (I don’t want to start any arguments, but I was taught that tape is more of a thread protectant than an effective sealing agent) and, in addition to replacing a couple of well-worn hoses, we were up and running. And we never heard the compressor running first thing in the morning again.
Not all compressed air systems are as simple as that, though. Many go from a room with several large & sophisticated air compressors, to corners of every building on the grounds. Through valves & manifolds, to cylinders, machinery and blow offs, with more connections than you could soap-and-water check in a month.
In those cases, the EXAIR Model 9061 Ultrasonic Leak Detector makes short(er) work of finding the leaks. With both visual (LED’s on the face) and audible (headphones) indications, even very small leaks are easy to detect with the parabola installed. The precise location can then be found with the tubular extension.
You’ll still have to fix the leaks yourself, but finding them is oftentimes more than half the battle. And, once fixed, it can be worth a million (cubic feet of compressed air, that is.)
EXAIR’s Ultrasonic Leak Detectors are not only useful for finding compressed air leaks; they’re popular in a variety of other areas:
- Maintaining military aircraft fluid systems on a naval warship.
- Locating leaks in products identified by a pressure loss indicator.
- Making the change from messy liquid pressure testing to quick & clean air testing.
- Vacuum system leak detection.
- Fire prevention system testing and maintenance. More than once, in fact.
- Finding leaks in a bus roof.
- Checking paint guns for leaks.
- Installing the refrigerant system in an ice rink floor.
Additionally, they can be used to identify faulty bearings, brake systems, tire & tube leaks, engine seals, radiators, electrical relay arcing…anything that generates an ultrasonic sound wave. If you’d like to find out more, give me a call.
An often debated subject is whether it makes more sense to use a compressed air powered Air Knife or a blower powered Air Knife. Initially, one might think that the blower option might be a more economical solution due to its slightly lower electrical consumption when compared to an air compressor. However, a blower powered Air Knife is an expensive capital expenditure that requires frequent downtime, costly maintenance of filters, belts, bearings and electricity! They also take up a lot of space and can produce sound levels that exceed OSHA noise level requirements. EXAIR’s Super Air Knife even when operated at 80 PSIG (5.5 BAR), is surprisingly quiet at 69 dBA!
Another drawback for the blower powered Air Knives is the air volume and velocity can be difficult to control since these are adjusted mechanically.
Some other important maintenance considerations are:
- Filters must be replaced every 1 – 3 months.
- Belts must be replaced every 3 – 6 months.
- Blower bearings wear out quickly due to the high rpm requirements.
- The Seals wear and can allow dirt and moisture to enter, couple that with high temperature environments and the bearing life will be reduced.
- Blowers typically add heat to the air flow, making it unsuitable for cooling applications.
In contrast the award winning and highly efficient EXAIR Super Air Knife represents our latest generation of innovation that dramatically reduces compressed air usage and noise, with no moving parts!
The EXAIR Super Air Knife is a great way to clean, dry or cool parts because they deliver a uniform sheet of laminar air flow across it’s entire length with force that can range from a gentle breeze to extreme hard-fitting force!
EXAIR Super Air Knives highly engineered design entrains ambient air at a ratio of 40:1. This simply means that for every (1) part of compressed air supplied (40) parts of ambient air are pulled into the compressed air stream exiting the nozzle.
1). Compressed air flows into the plenum of the Super Air Knife. The flow is directed to a precision slotted orifice.
2). As the air-flow exits the air gap it follows a flat surface that directs the air flow in a perfectly straight line. This creates a uniform sheet of air across the entire length of the Super Air Knife.
3). Velocity loss is minimized and force is maximized as the room air is entrained into the primary air-stream at a 40:1 ratio. This all results in a well defined sheet of laminar air-flow with hard hitting force.
Advantages of the Super Air Knife
- Very Quiet, typically 69 dBA for most applications
- Minimal Compressed air consumption
- 40:1 air amplification
- Uniform air flow across the entire length
- Force and flow are variable
- No moving parts – therefore maintenance free
- Easy mounting – compressed air inlets are conveniently located on each end and the bottom
- Compact design, rugged design and very easy to install
- Recessed hardware
- Stock lengths up to 108″ in Aluminum (max temperature of 180°F/82°C), 303SS or 316SS (max temperature 800°F/427°C)
- PVDF is available up to 54″ long for superior corrosion resistance (max temperature 275°F/135°C)
EXAIR’s Super Air Knife is also a great replacement for other commonly used, but highly inefficient and noisy compressed air operated devices.
As an example, two commonly used blow-offs are the drilled pipe and flat air nozzles installed into a pipe. EXAIR performed a head to head test employing the EXAIR Super Air Knife, Blower Powered Air Knife, Drilled Pipe & Plastic Flat Nozzles mounted in a pipe.
Below are the results of that test from a very common application, blowing water off bottles. As shown in the First Year Cost Column it becomes clear that the true cost of ownership needs to be considered. Many plants are surprised at how efficient the EXAIR Super Air Knife is compared to other alternatives.
Another important consideration is how effective these other blow-off methods are. The drilled pipe and flat air nozzles have “dead spots” where the air flow is non existent leaving some of your product wet and/or dirty.
When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call. We would enjoy hearing from you.
This week I wanted to present the Deep Hole Vac-u-Gun, a special iteration of the Vac-u-Gun, designed to provide a solution to the troublesome process of cleaning cavities and drilled holes.
The Deep Hole Vac-u-Gun is a low cost solution to quickly remove chips and debris from grooves and drilled holes where blow gun could create potentially hazardous flying debris. The Deep Hole Vac-u-Gun is simply positioned over the hole, and the trigger squeezed and then a small blow tube delivers a a stream of air to dislodge and lift the chips while the large suction tube vacuum them away. The operator is protected form flying debris since all chips and debris is contained within the clear suction tube. The device is capable of cleaning holes up to 1-1/4″ (32mm) diameter and 18″ (457mm) deep!
How does the Deep Hole Vac-u-Gun work?
Compressed air, normally 80-100 PSIG (5.5 – 6.9 bar), flows through the inlet (1) into an annular plenum chamber (2) when the trigger is pressed. A small amount of air is injected into the blow tube (3) to provide agitation and lift to the chips or debris. The larger airflow is injected into the the throat of the gun through directed nozzles (4). The jets of air create the vacuum at the intake (5) which draws the material in and accelerates it through the unit. The chips, debris or other particulates can then be exhausted into a filter bag or hose attached to the Deep Hole Vac-u-Gun System.
We have found many applications where the Deep Hole Vac-u-Gun is beneficial- including removing chips and debris in:
Holes in fixtures, drilled plastics, T-slots’groove cleaning , coolant evacuation from parts, woodworking, tapped holes, cavity evacuation, and many more!
There are many advantages to the Deep Hole Vac-u-Gun, and some are:
Low cost, no moving parts/maintenance free, durable die cast construction, eliminates shock hazard – no electricity, meets OSHA pressure requirements, safe operation – no flying chips, lightweight and portable, and quiet.
The Deep Hole Vac-u-Gun uses less compressed air than ordinary blow guns, and the amplified output flow is 12 times the air consumption rate.
Note that the Deep Hole Vac-u-Gun should not be operated without a filter bag or vacuum hose attached to the exhaust.
There are three (3) Deep Hole Vac-u-Gun System options-
The Model 6094 is the Deep Hole Vac-u-Gun only.
The Model 6194 comes with a reusable bag and clamp for debris collection.
The Model 6394 comes with the reusable bag and a 10′ (3m) section of vacuum hose for transferring the debris to a collection point.
If you have questions about the Deep Hole Vac-u-Gun or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.