EXAIR Provides Blow Off And Static Solution Within Tea Machine

I mentioned in one of my last blogs about how having a camera phone can come in handy when discussing applications.  If there is anything unclear about a description, a quick photo and email can clear things up.

Thankfully, a potential end-user of EXAIR products was proactive and took the liberty to send the video above and the photos below along with a description of their problem.

Tea bagging machine
Internal components of the machine
Internal components. Note the existing vacuum hose.
Another image of the machine internals.

This is a tea bag making and filling machine.  Inside of the machine, as the tea bags are made and filled with tea, a small amount of dust is created with each bag.  Over time, this dust becomes substantial and collects, and must be removed to prevent disruptions in quality and processing.

The difficulty for this end user, in addition to needing to vacuum the material with something that could withstand this high dust concentration, was that the dust adhered to the machine components due to a static charge.

Tea dust statically adhered to the machine
Statically charged tea dust

With the strong static attraction in place, only vacuuming the material could not remove the fine dust sticking to the machine parts.  What they needed was a way to neutralize the static charge so that the dust could be released from the machine components.

We recommended a two-tiered approach.  During one portion of the solution, an Ion Air Jet would provide ionized (static eliminating) air onto a deliberate area while an operator used a Heavy Duty HEPA Vac to vacuum the dust from the same location.  We were, in effect, freeing the dust from the static cling and immediately vacuuming it away.

This was great, except the solution needed to function during machine operation, which meant having an operator standing by was not an option.  So, we had to go back to the drawing board.

In re-examining the application, we noted the existing vacuum lines in place, and considered a way to add addition vacuum.  What we determined was that a pair of Line Vacs could remove the tea dust, but we had to ionize the air in the the chamber in order to remove the static.

The problem with a more permanent installation to remove the static is that the dust present within the machine could pose a problem for the longevity of an ionizer.  Our only option would be to generate the ionized air externally and feed it into the machine, though such an arrangement is not highly desirable because when ducting an ionized airflow, the static eliminating ability of the air is reduced.

This meant that we needed a one-way entrance for the ionized air which did not induce turbulence and deteriorate the static eliminating abilities of the solution.  We came to a proposal to use a 12” Super Ion Air Knife mounted at the top of the machine used in conjunction with an actuated door approximately 12” x 2”.

With everything controlled via the same ladder rung in a PLC, the door actuator and compressed air supply to the Super Ion Air Knife and Line Vacs will engage simultaneously.  The door will open, the knife will blow ionized air, and the Line Vacs will provide additional vacuum for the airborne tea dust.  The vacuumed tea dust will be fed into the existing dust collection system.

The solution is currently being presented to the key stakeholders involved with this application.  If any questions arise, we will be here to help provide any answers we can.  If you have a similarly unique application and need a solution, or just need to brainstorm, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer

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