FAQ

1. What is the difference between the Super Air Knife and the Standard Air Knife?
2. How do I mount your air knives?
3. What are the temperature limits for your air knives?
4. Can I operate your air knives with a blower?
5. We have some dead spots on our air knife. What should we do?
6. Can I connect the output of a Vortex Tube to an Air Knife?
7. I see that you have air knives up to 48" long in your catalog. Can you make a longer one if I need one?
8. What kind of maintenance is necessary for an ionizing bar?
9. We removed the static charge with your ionizer, but it keeps coming back. Why?
10. What does your static meter tell me?
11. Why won't your static eliminators demagnetize my metal parts ?
12. Which static eliminator should I use?
13. Where should I position your ionizer in my process?

1、What is the difference between the Super Air Knife and the Standard Air Knife?

The Super Air Knife is EXAIR Corporation newest Air Knife design. It is used when the most efficient air consumption, noise generation, or very precise airflow characteristics are necessary for success in an application. It has the ability to flow air along the full knife length, has an amplification ratio of 40:1 and incorporates two sets of compressed air inlets for flexibility in supplying compressed air. The Super Air Knife is 6 times quieter than the Standard Air Knife, and reduces compressed air usage by 15% when compared to the Standard Air Knife.
The Standard Air Knife is EXAIR Corporation original design Air Knife. It utilizes the coanda Effect to create large volumes of airflow from a relatively small volume of compressed air. The signature of this style of Air Knife is that it causes the airflow to bend 90 degrees around a coanda profile to induce ambient air at an amplification ratio of 30:1. It has a smaller profile and is less expensive.

2、How do I mount your air knives?

The Air Knives can be mounted in a variety of ways. The most common method is to use the compressed air pipe to support them. There are 1/4 NPT female threads on both ends into which the pipe can be threaded. Position the Air Knife where you want and then strap the pipe into place.
Another way to mount the Air Knife would be to use one of the 1/4-20 button head cap screws used to mount the cap to the body of the Air Knife to secure a bracket of your own fabrication. You will need to replace the screw with one longer in size depending on the thickness of your bracket.
Another way to mount the Super Air Knife would be to utilize the 1/4-20 tapped holes on the bottom of the Super Air Knife. There is about 3/8?depth of thread to use for a bracket to be bolted to the bottom of the Super Air Knife.

3、What are the temperature limits for your air knives?

Aluminum Air Knife with plastic shim: 180°F(82°C)
Aluminum Air Knife with stainless steel shim: 400°F (205°C)
Stainless Steel Air Knife with plastic shim: 180°F (82°C)
Stainless Steel Air Knife with stainless steel shim: 800°F (427°C)*
*Temperatures that exceed 800°F (427°C) may produce intergranular corrosion that can eventually plug the air gap opening.

4、Can I operate your air knives with a blower?

No, blowers are not a source of air for Air Knives. Air Knives are designed to use compressed air. Blowers are large, expensive and noisy with 3?to 6?outlet connections. They do not produce enough pressure to operate an EXAIR Air Knife.

5、We have some dead spots on our air knife. What should we do?

The flow characteristics of the Air Knife (Super or Standard) have been tested before it was shipped. We suggest that you follow the disassembly instructions and inspect the Air Knife for dirt contamination. Cleaning instructions can be found on the installation and maintenance sheet shipped with the Air Knife or in Adobe Reader PDF format on our web site. A second possibility is that the Air Knife has been undersupplied. Do not use restrictive fittings, undersized line or filters that may not allow enough airflow into the plenum chamber of the Air Knife. Air Knives that are 18?or longer must be supplied at two compressed air inlets at opposite ends of the Air Knife. A third possibility is that the screws may have been over tightened during mounting or during reassembly. Screws should be tightened snugly (7.5 ft/lbs).

6、Can I connect the output of a Vortex Tube to an Air Knife

No, for proper operation, the Vortex Tube cold outlet should not be subjected to any restrictions that would produce backpressure in excess of 5 PSIG. An Air Knife would restrict the flow of a Vortex Tube to the point where the backpressure is excessive and severely limit the cooling capacity of the Vortex Tube.

7、I see that you have air knives up to 48" long in your catalog. Can you make a longer one if I need one?

Yes, EXAIR can manufacture any length of air knife that you require. Please contact an Application Engineer for details.

8、What kind of maintenance is necessary for an ionizing bar?

A soft bristle brush (a toothbrush works well) should be used to clean the emitter points and channel to remove any particulate. Do not use anything that will bend or dull the emitter points. Do not use any soaps or liquid cleaners that will leave a conductive residue. They can destroy the effectiveness and lifespan. A simple cleaning operation added to your planned maintenance schedule can eliminate potential performance problems. The frequency of cleaning required will depend upon the environment in which the ionizer is installed. Dirty industrial applications may require daily cleaning while clean-room applications may require only monthly cleaning. It is important to evaluate the cleaning needs of each individual ionizer installation.
Never clean an ionizer with the power on!

9、We removed the static charge with your ionizer, but it keeps coming back. Why?

The ionizer showers the product surface with positive and negative ions so the charge is completely eliminated. If that part or material experiences friction where it rubs against another surface, a new charge can be induced.

10、What does your static meter tell me?

Model #7905 Static Meter will indicate surface voltage and polarity up to 20 kV at a spacing of one inch with an accuracy of 5% full scale. The Static Meter will help pinpoint the location of the static trouble spots in your application.

11、Why won't your static eliminators demagnetize my metal parts

Static Eliminators are not designed to de-magnetize objects. Magnetic attraction and static attraction are two different phenomena that have nothing to do with each other. EXAIR Static Eliminators work to reduce static charges by providing positive and negative ions to the surface of a material to bring the total static charge back to neutral. Magnetic attraction is caused by lines of force created by the alignment of atoms in magnetized material.

12、Which static eliminator should I use?

Static Eliminators with air are ideal for hard to reach places or obstructed surfaces, products moving at high speeds, and surfaces with an extremely high charge. Air assisted ionizers include the Super Ion Air Knife, Standard Ion Air Knife, Ion Air Cannon, Ion Air Gun and the Ion Air Jet.

Static Eliminators without air fit situations where even the smallest amount of airflow can disturb the product, or space is extremely limited. The static eliminator must be mounted within two inches from the charged surface.

13、Where should I position your ionizer in my process?

Usually, the most effective place to install an ionizer is going to be shortly before the area of the process where the static field is creating problems (tearing, jamming, discharge to personnel, etc.) Sometimes multiple ionizers on a single process may be necessary due to static regeneration in the process. If the application is cleaning, the ionizer should be positioned shortly before packaging or finishing operations.
A static meter (Model 7905) is also available from EXAIR to determine the places in a process where the static generation is occurring. The static meter measures the polarity and magnitude of a given static field.