Author: Lee Evans

High Temperature Application Needs High Temperature Filtration

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Two 42″ stainless steel Super Air Knives in need of proper filtration of the compressed air supply

In an undisclosed application, two 42” stainless steel Super Air Knives (shown above) are positioned to provide a needed blowoff function.  The exact purpose of the blowoff wasn’t revealed, but this OEM requested various shims for these knives along with suitable filtration.  Shims, which can be field installed into the knife to adjust the air gap and air flow due to different thicknesses, will directly affect the volume of air and force out of the knife. Determining model numbers and pricing for the requested shims is straightforward, but providing the required filtration proved to be a bit more challenging.

Whenever considering filtration, the first step in product selection is to consider what needs to be filtered from the air; for example, water, dirt, or oil.  This customer needed a method to remove both water and dirt, as well as oil particulate from the compressed air.

The next step is to consider the potential greatest flow (required by the knives) through the filters, which, in turn, requires having knowledge of the intended operating pressure for the application and the air gap set by the shims.  These knives are to be operated at a maximum pressure of 87 PSIG, creating a maximum flow potential of about 260-520 SCFM depending on the chosen shim.  (3.1 SCFM per inch of length for each knife when operating at 87 PSIG * 42 inches per knife * 2 knives = ~260 SCFM;  6.2 SCFM per inch of length for each knife when operating at 87 PSIG and having the additional shims installed * 42 inches per knife * 2 knives = ~520 SCFM)

Lastly, we have to give consideration to the environment into which the filters will be installed.  For example, will the filters be exposed to any kind of wash-down process using specific chemicals; and, what is the ambient temperature in the environment?  The purpose of these questions is to uncover any environmental specifications or limitations.

In this application, those questions uncovered a need to place these filters into a hot environment with temperatures up to 300°F.  Given that our stock filter options have maximum operating temperatures of 120°F, we needed to explore an application-specific solution.

So, the Engineering team at EXAIR sprung into gear to find a suitable, high temperature option, which we in turn presented to the OEM user, offering a specific solution for their specific application.  The high temperature filters for this application are suitable for temperatures up to 450°F with flow rates as high as 600 SCFM at 100 PSIG – a perfect fit!

If you have application-specific needs, we’re happy to discuss and brainstorm potential solutions.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Conveying Valve Keepers with a Line Vac Air Operated Conveyor

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Valve keepers

In some of my previous blogs I’ve written about rebuilding engines at home, usually finding a decent car that suffered top-end engine damage.  Sometimes the root cause is a lack of oil pressure, other times it is a failed component in the valve train, or something as simple as a broken timing belt.  In any case, these rebuilds tend to involve removing the cylinder heads from the engine, disassembling them and replacing the damaged components.

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These valve keepers need to be pneumatically conveyed

A commonly damaged component with timing belt or valve train failure is the valve.  And, removing the valve means removing the valve keepers, which are the items shown above.

I received an email from our distributor in Italy, searching for a solution to convey these valve keepers at a rate of approximately 5000 per hour over a distance of 3 meters and a height of 4 meters.  The valve keepers are quite light, weighing just 0.29 grams each – a perfect fit for use with the Line Vac.

When considering a conveyance application we take into account several variables such as:

Bulk density of the material

Shape/size of the material

Conveying distance

Conveying height

Required conveyance rate

Available compressed air supply

Given the need to convey 5000 valve keepers per hour at a weight of 0.29 grams/valve keeper, we only needed to move ~1.5kg per hour for this application.  When considering the height and distance involved, and the size of the valve keepers, we can comfortable convey these units with a ¾” Line Vac or a 1” Line Vac.  Using 10.7 and 14.7 SCFM, respectively, these options provide a suitable solution with a low compressed air demand.

If you have an application in need of a compressed air solution, contact an EXAIR Application Engineer.  We’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

1st photo credit to Benjamin Hirsch (Creative Commons License)

Engineered Flat Air Nozzles Remove Oil from Parts & Eliminate Packaging Rejects

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Coating station for tapered roller bearings

A few months ago I helped an end user find a solution to remove residual oil from u-joints (technically termed “spiders”).  As the u-joints moved through the application, lubricant would accumulate in the bottom of a collection area.  This accumulation presented problems in the next phase of the process, and a method to remove the oil from the u-joints was the perfect solution.

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Transfer “gutter”

Fast forward a few months and a similar application has surfaced.  In the new application, tapered roller bearings are coated in lubricant and then transferred from the coating station through a metal gutter and into a transporter.  At the end of the process the bearings are placed into packaging, and excessive oil is leaking through the packaging.  The affected packages are deemed defective, resulting in rework for the bearing manufacturer.

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Bearing transporter. After moving through this stage of the process the bearings are packaged for delivery.

Similar to the original application, we found a solution through the use of an engineered air nozzle setup.  Model 1122 Super Air Nozzles and 12″ Stay Set Hoses can mount to the coating station using magnetic bases.  The airflow from the nozzles are then aimed over the bearings to remove excessive lubricant, effectively removing the root cause of the packaging defects.

By removing the excess lubricant at the lubricating station (which is equipped with a slotted table), the excess oil is channeled through the table and into a collection bin.  The end user is then able to reclaim the same oil which would leak through the packaging and cause defects.  So, in addition to solving a problem related to defects, the end user is also able to reduce wasted lubricant in the process.

Reducing defects and lowering material use in this application is made possible through the correct application of an engineered blow off solution.  If you have a similar application or think an engineered solution may benefit your application, contact an EXAIR Application Engineer.

 

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Super Air Nozzles Extend Maintenance Schedule in a Chocolate Factory

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The process of making cocoa powder and chocolate products is fascinating to say the least.  The video above shows the process at the Hershey factory in a throwback “How Its Made” video from the 70’s. (I think; based on the hairstyles.  Also based on the video description, but mostly based on the hairstyles.)  It’s interesting to see the process and the mechanical aptitude it took to create the machines, especially with the weights and measures.  The level of complexity and number of steps involved can make you wonder how we ever figured it all out, but thankfully we did!

Current cocoa production follows the same basic process through harvesting, roasting, extracting cocoa butter, and grinding of cocoa cakes into powder.  And, like any manufacturing process, there are sure to be applications which demand unique solutions.  This is where a recent application took place for an EXAIR end user.

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The cooling carriage for the cocoa powder

Not shown in the video above is a cooling process for the cocoa powder.  During the cooling process the powder is transferred through a carriage system resembling a radiator without the fins.  Inside the carriage system cocoa powder can accumulate in the 180° bends, and the build-up over time can stop material flow.  So, these bends are serviced as part of a regular preventative maintenance program.

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Cocoa build-up in the curves of the carriage

The end user was looking for a way to extend the service interval length, hoping to find a solution to target the build-up areas in the 180° bends.  The current setup requires manual cleaning every 15 days of operation.  Modification of the existing setup is possible, provided it increases the time between maintenance procedures.

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The service procedure

The solution we devised is a series of 316 stainless steel Super Air Nozzles, fed into the curves of the cooling carriage to prevent accumulation of the cocoa powder.  The solution agitates any accumulating cocoa, removing the build-up and greatly extending the time between service intervals.

This solution can be implemented in one of two ways; either through periodic entry of the nozzles into the cooling carriage (a somewhat difficult solution to implement), or through permanent installation with guarding in place to protect the nozzles (even powders can deteriorate a material with direct contact over time).  A (very) crude representation of the permanent installation is shown below.

Cocoa curves
A quick sketch of the possible permanent solution

To install the nozzles into the curves of the cooling carriage, holes must be drilled into the curves.  Sealed bulkhead fittings can be installed into the holes, and the necessary compressed air lines can be fed through the sealed bulkhead fittings.  This will allow installation of the air nozzles in the needed locations.

The final detail left to be sorted in this application was the exact model Super Air Nozzle to be used.  The force requirement to dislodge the cocoa is highly specific and ultimately unknown, so we focused on a solution with what we deemed adequate force at an 80 PSIG operating pressure.  We chose a series of 1101SS Super Air Nozzles, remembering we can always reduce force and compressed air consumption through pressure regulation if needed.

We were happy to help implement a solution to provide the needed results with the most efficient use of compressed air.  After all, that’s what we do at EXAIR.  We help our customers find the most suitable, most efficient solutions for their applications.

If you have an application and would like to discuss a compressed air-based solution, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com