With frequent use or when filtering out long stringy chips, the liquid flow passageways of the EXAIR Chip Trapper may become blocked with machining debris. The video below walks you through the simple process, to clean out the directional control valve of the Chip Trapper, should you ever need to perform this service. All that is needed is a regular screwdriver, a Phillips screwdriver and a marker.
Thanks to Bensound (www.bensound.com) for the royalty free music in this video!
A few days ago I was working with a customer who was having a dust issue with their bottling line. As the polypropylene bottles travel down the slow moving conveyor, they are rinsed with an antibacterial solution then blown dry. After that, they pass under an inspection “eye” where they are checked for impurities before being filled with their herbal supplement tablets. When any dust is detected, the conveyor shuts down and the bottles have to be removed from the line and manually cleaned, then the system has to be reset to resume production. With the frequency of rejects increasing and the loss of production time, they decided to contact EXAIR for assistance.
After discussing the application with the customer, their immediate needs were two fold:
1. Remove any contaminants in the bottle.
Install a sensor on the line to detect the bottle, so they only use compressed air when needed.
For their first requirement, I recommended our Stay Set Ion Air Jet. Because dust and debris can stick to plastic bottles due to a static charge and because I had learned the bottles did rub against each other and plastic guide rails, the static eliminating qualities of Stay Set Ion Air Jet could be helpful. This would provide a focused, high velocity flow of ionized air capable of eliminating the static inside the bottle, while the airflow carries any particulate away. The unit features our Flexible Stay Set Hose which allows an easy way to direct the air to the critical area while holding position and a Magnetic Base for easy installation.
Secondly, I recommend our EFC Electronic Flow Control to address their compressed air usage concern. The EFC incorporates a timing controlled (0.10 seconds to 120 hours) photoelectric sensor that sends a signal to the solenoid valve to turn off the compressed air supply when there are no parts detected. There are also eight additional programmable on/off modes that can be easily tailored to fit a specific demand.
For help with your specific application, please contact one of our application engineers for assistance.
My previous blog post was about how Vortex Tubes react when there is back pressure due to a restriction on either the hot or cold discharge of the Vortex Tube. In it I mentioned that there is a formula to calculate what the cooling capacity (Btu/Hr) will be if there is no way to avoid operating the Vortex Tube without back pressure on the discharge. That is the calculation focus of this blog – calculating Btu/hr of a Vortex Tube with back pressure.
To continue with the same example, the calculations from the previous blog are shown below. Last time the example Vortex Tube was operating at 100 psig inlet pressure, 50% cold fraction, and 10 psi of back pressure. We will need some additional information to determine the Btu/Hr capacity. The additional information needed is the temperature of the supplied compressed air as well as the ambient air temperature desired to maintain. For the example the inlet compressed air will be 70°F and desired ambient air temperature to maintain will be 90°F.
(100 psig + 14.7 psia) / (10 psig + 14.7 psia) = X / 14.7 psia
4.6437 = X / 14.7
X= 14.7 * 4.6437
X = 68.2628
(Values have been rounded for display purposes)
The calculation above gives the compensated operating pressure (X = 68.2628) which will be needed for the BTU/hr calculation. The rated air consumption value of the Vortex Tube will also need to be known. A 30 SCFM rated generator will be used for this example, the normal BTU capacity of a Vortex Tube with a 30 SCFM generator is 2,000 BTU/hr.
First, determine the new consumption rate by establishing a ratio of the compensated pressure (68.2628 psi) against the rated pressure (100 psi) at absolute conditions (14.7 psia).
Second, the volumetric flow of cold air at the previously mentioned cold fraction (50%) will be calculated. To do this multiply the cold fraction setting (50%) of the Vortex Tube by the compensated input consumption (21.7 SCFM) of the Vortex Tube.
50% cold fraction x 21.7 SCFM input = 10.85 SCFM of cold air flow
Third, the temperature of air that will be produced by the Vortex Tube will need to be calculated. For this consult the Vortex Tube performance chart which is shown below. To simplify the example the compensated operating pressure (68.2628 psi) will be rounded to 70 psig and to obtain the 70 psig value the mean between 80 psig and 60 psig performance from the chart will be used.
For the example: A 70 psig inlet pressure at 50% cold fraction will produce approximately an 88°F drop.
Fourth, subtract the temperature drop (88°F) from the temperature of the supplied compressed air temperature (70°F).
70°F Supply air – 88°F drop = -18°F Output Air Temperature
Fifth, determine the difference between the temperature of the air being produced by the Vortex Tube (-18°F) and the ambient air temperature that is desired (90°F).
90°F ambient – -18°F air generated = 108°F difference.
The sixth and final step in the calculation is to apply the answers obtained above into a refrigeration formula to calculate BTU/hr.
1.0746 (BTU/hr. constant for air) x 10.85 SCFM of cold air flow x 108°F ΔT = 1,259 BTU/hr.
In summary, if a 2,000 BTU/hr. Vortex tube is operated at 100 psig inlet pressure, 50% cold fraction, 70°F inlet air to maintain a 90°F ambient condition with 10 psi of back pressure on the outlets of the Vortex Tube the cooling capacity will be de-rated to 1,259 BTU/hr. That is a 37% reduction in performance. If a back pressure cannot be avoided and the cooling capacity needed is known then it is possible to compensate and ensure the cooling capacity can still be achieved. The ideal scenario for a Vortex Tube to remain at optimal performance is to operate with no back pressure on the cold or hot outlet.
An application we see from time to time involves the cooling of camera lenses as they “watch” for various materials in automated processes. The process usually involves some sort of part detection, checking object specifics for adherence to quality standards, or searching for items in need of rejection. These process are often fully automated, requiring the camera to process a continuous stream of information and to be housed in the same environment as the materials being monitored.
At a waste sorting facility in France, an end user was experiencing an overheating of their camera. The result of the overheating condition was unwanted downtime while the internal camera electronics cooled and could not be used. This meant that an expensive, complex, and efficient piece of equipment was out of service, creating a bottleneck in the waste sorting process.
To solve this overheating condition, the end user worked through the EXAIR distributor in France, Kermaz Pneumatic, to find a solution with an EXAIR Vortex Tube. The Vortex Tube was installed so that cold air was created and supplied directly into the camera lens housing. The end result was a reduction in heat at the camera lens, allowing the machine to function at full capacity without stoppage, effectively removing the process bottleneck.
If you have a similar application and think EXAIR may be able to help, contact an EXAIR Application Engineer.
Sometimes you just need a little adjustment. I received a call from a customer that had 2 pieces of our model 110018SS stainless steel Super Air Knives. They were blowing water off the bottles before labeling. They increased their production rate to 300 bottles/minute, and they started seeing issues with the labeling process. They determined that the bottles needed to be drier and wondered if we could help. This customer has been using these air knives for over 5 years without any issues. With the increase in production rate, they wondered if they needed to add a shim to increase the performance of the Super Air Knives. I wanted to verify that he was maximizing the efficiency of the Super Air Knives before we started to make any changes.
The customer sent me pictures of his operation for diagnosis (reference above), and I noticed that the Super Air Knives were blowing air right at each other. The position of each Super Air Knife from top to bottom was correct. This is recommended for removing water in a counter-flow direction (when the bottles are traveling from the right side of the picture to the left side). But the blowing direction was incorrect for optimal efficiency. For an application similar to this, we want to increase the contact time on the bottles. The longer the bottles are in the path of the Super Air Knives, the more time we have in removing the water. I sent him a picture of an application that was very similar to his (reference below). It shows the Super Air Knives at the correct blowing angle. As you can see, the Super Air Knives are aimed more toward the center of the conveyor, and not at each other.
In the first picture, I noticed that this customer also purchase the model 9060 Universal Air Knife Mounting System to go with his Super Air Knives. This mounting system is designed with stainless steel hardware for secure, precise positions, and it allows the air knife to quickly and easily be mounted and adjusted. With a quick turn of the knobs, he was able to set the correct angle very simply, and improve his operation. Sometimes you can step back for a moment and return to the basics to improve your system. In this case, he did not have to add a shim to blow more air, but just reposition the Super Air Knives for a more efficient process.
Swivels, an accessory for our air nozzle product line, provide a similar function and allow customers to adjust air nozzles to their most effective position. If you believe that you are not getting the most out of your compressed air system, you can contact an Application Engineer at 800-903-9247.
Our Greek distributor came to me the other day with a production issue for one of his clients. They manufacture foam in a variety of forms for many different end uses. In this particular case, the customer was working with a flat web of foam. As they are un-rolling and processing the foam, a decent amount of static charge builds up on the material which eventually causes discharges to the rollers in the machinery and to operators as well. The discharges are dangerous to personnel as they can be quite potent, causing a reflexive jerk back which can put the operators into a dangerous position with respect to machine components, not to mention that they are just flat out uncomfortable to receive. Another issue is that the discharges also cause blemishes on the surface of the white foam where they occur. Such blemishes are considered a defect and are therefore another reason that the customer wants to investigate active static elimination.
As you can see in the above photo, the customer has a couple of ground “probes” if you will, that ride on the surface of the foam web. They do this in hopes that the charges will “drain off” to Earth ground. While this kind of “passive” static elimination can be useful in certain circumstances, many times is just not sufficient to completely neutralize the material as needed for the process. We reviewed the line speed in the application and the web was moving at a reasonably slow 10 – 15 meters per minute. With this in mind, the EXAIR Ion Bar would be a perfect fit to provide the necessary ions to “actively” discharge the electrostatic field. By actively, I mean that the ion bar produces positive and negative ozone ions which are actively delivered and come into contact with the material. This causes the net charge to drop to a much lower level than simple grounding techniques just cannot get to.
With the very coldest of winter-time temperatures upon us now, it is what we term “static season” due to the low humidity in the air. Processes like this one can be rendered hopeless without the use of some form of active static elimination.
Are you in a converting business of some kind? Do you have static issues in your processes? If so, consider contacting us for some help with your application. Static electricity in a production environment does not have to be a problem.
Do you like soup? I like soup. Especially on cold days in the winter. Living down south apparently ruined me for cold weather, because, even though I’ve been here in Ohio for 25 years, I still get a chronic chill in early November that won’t let go until about April. March, if I’m lucky. A nice, hot bowl of soup gives me a temporary respite from that dreaded chill, though, so yeah…I like soup.
Sometimes (OK; most of the time) I like it so much I don’t want to wait for it to cool (just slightly) to a temperature that won’t scald my tongue, so I resort to the age-old practice of blowing on those first few spoonfuls. Even though my breath is a fairly consistent 98.6F (give or take,) it’s still quite effective at transferring enough heat out for pain-free consumption. There are two reasons I’m thinking about this right now:
First reason: I’ve been working with an engineer at a large automotive plant…they were cooling a production run of metal cast parts with a series of fans. It ran pretty slowly, and they had a line of those pedestal mounted fans “waving at the parts as they went by.” The thought was, they could direct a stream of cooling air by using the focused flow of an Air Amplifier, and this might just allow them to speed up the line. And they were right. They tried a few Model 6041 1-1/4″ Aluminum Adjustable Air Amplifiers, with very favorable results. So favorable, in fact, that they ordered (40) more to outfit other casting lines in the plant, in arrangements similar to this:
Just like it might take more than one “blow” to cool off a spoonful of soup, they have installed multiple Air Amplifiers, in succession, on the lines, depending on the size, shape, and mass of the part. And the precise adjustability of the Adjustable Air Amplifiers allows them to dial in the optimum air flow, while minimizing their compressed air consumption. So the Production and Facilities folks are all very happy.
And (because I know you’re wondering) the second reason I’m thinking about conductive/convective heat transfer via air movement: