Tag: sand

OmniStream Cone Nozzles And Metal Casting

Published on by Russ BowmanLeave a comment

As a child of the 1970s, my friends and I played with a LOT of toys that were die-cast. Most of us didn’t know what that meant; we just knew that we had to try REALLY hard to break them. Turns out, the ruggedness of those toys – and their widespread availability to the first crop of Gen-X kids – is directly related to the casting process. Metal casting produces stronger products than welding pieces together, and it’s WAY more cost-effective than machining parts that don’t necessarily need to hold tolerances measured in thousandths of inches.

One of the more popular methods for parts & products like this is called green sand casting. Basically, they add a specific amount of water to the sand so that it’ll hold its shape – that’s why the best sand castles on the beach are made closer to the surf – and make a mold. Then they pour in molten metal, let it cool, remove the cast part, and repeat for as many parts as they need to make. Fun fact: they call it “green sand” because of the moisture content – like “green wood” gets its name because of the sap content – not because of the color (it’s NOT green colored).

Anyway, the mixing process for the sand & water blend is kind of an exact science. Too much water, and the mold won’t hold its shape, and too little will make it brittle. It’s also easier and quicker to mix if the water is sprayed, as opposed to dumping or pouring it in.

The reason I know all this is that I had the pleasure of talking with a caller who runs a specialty casting foundry. They make parts that weigh a couple of ounces, a couple of hundred pounds, and anything in between. They, of course, keep the molds they’ve made for repeat customers, so they’re ready to go when a new order is placed, but they’re also making new molds all the time, and wanted to improve the sand/water mixing process. They didn’t need the extremely fine droplet size of an Air Atomizing Spray Nozzle, nor did they want something whose flow was measured in gallons per hour. They were actually looking for about one gallon per minute from a compact device that could spray a wide round pattern into a rotary drum that looked an awful lot like a small concrete mixer. They chose Model FL1010SS OmniStream Cone Nozzle.

Since 1 gallon per minute is right in the middle of the FL1010SS’ flow performance range, it was the obvious choice for this application.

As the sand in the mixer turns, the conical spray is evenly, and quickly, is soaked into the sand. This reduced the time it took to get a consistent mixture, and eliminated clumps they’d occasionally get when the water was poured in, which they’d have to break up by hand after stopping the mixer, which saved even more time…and operator frustration!

If you need to spray liquid in a consistent, repeatable manner, EXAIR has an enormous range of flow rates & spray patterns. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Line Vac Removes Debris In Fuse Manufacturing

Published on by Lee EvansLeave a comment

Over the last few months I’ve had the pleasure of working with an automation house headquartered in the U.S.  This company provides automation solutions to businesses from the states and abroad, and has a variety of applications, particularly for the Line Vac.  We began our discussions about transferring plastic pellet material into a multi-stage hopper atop a large machine, and progressed into other potential applications.

One of those applications was in the evacuation and reuse of sand used during a filling process for semiconductor fuses.  Fuses often contain high purity quartz sand as a granular filler.  The grain size distribution of the sand is of particular importance, as it provides room for vapors and gases to expand in the event of an arc.  So, making the most of the specified sand is a priority for the manufacturer.  The sand also offers a large surface area for efficient cooling and absorption of enormous amounts of energy.  In the event of an arc, the sand melts, forming a non-conductive body that prevents any further current flow.

Our customer in this application needed to remove the sand leftover at the top of the fuse after filling.  The existing setup provided no vacuum system, creating a mess of sand in, and around the filling station.

Line Vac Fuse 2
Semiconductor fuse filled with sand

The solution we came to was to install a 6078 or 6058 Line Vac, depending on the impact to the machine budget for each model.  (Note: The 6078 and 6058 Line Vac have identical performance, however, they are made of different materials – aluminum vs. 303 stainless steel – and thus have different costs.)  The Line Vac will vacuum the sand from the workspace, and convey it to a nearby container for reuse.

By recovering and reusing this sand, the machine area is cleaner, employees no longer have to sweep up and discard the spilled material, and the machine throughput can be increased.  Recovering the spilled material saves both time and money while increasing production capabilities.

With a Line Vac installed, we aim for a machine workspace that looks like this:

Line Vac Fuse 1
A nice, clean workspace

If you have an application that may benefit from an EXAIR product, or a discussion with an EXAIR Application Engineer, give us a call.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

Award Winning HEPA Vac

Published on by Dave WoernerLeave a comment

Continuing my series of EXAIR award winning products for 2014.  Plant Engineering’s readers voted the Heavy Duty HEPA Vac a silver award for Environmental Health. The HD HEPA Vac differs greatly from most of the EXAIR products.  We often improve a work environment by reducing noise level from compressed air blow offs or limiting the energy usage of a facility by conserving compressed air, but when EXAIR introduced the Heavy Duty HEPA Vac, we entered a new area of environmental health.

hepafam_collection

High Efficiency Particulate Air standards are set by the US Department of Energy. Originally, the standards were created to protect workers, the public and the environment from particulate that may be found in DOE’s nuclear facilities. (For more information on HEPA filtration consult DOE-STD-3020-2005.) The Heavy Duty HEPA Vac filter meets the HEPA standards to filter a minimum 99.97% at 0.3 micron level.  Each filter is tested in strict accordance with IEST-RP-CC-007. After testing the filtration, vacuum and ventilation companies discovered the added benefit of using HEPA filtration is to remove particulate that may inflame allergies or asthmatic symptoms. Pollen, pet dander, and dust are physically too large to pass through the HEPA filter. For instance, most pet dander is 5 microns and will become trapped inside the circuitous air passage route inside the HEPA filter. Also, HEPA filters will even filter airborne pathogens.  Engineering Toolbox list several nominal particle sizes to give you the idea of scope. By meeting these strict standards, EXAIR’s Heavy Duty HEPA Vac can be used in a whole new industry where HEPA filtration is required.

Tries to imitate the late Billy Mays

But wait there’s more!

We haven’t even talked about the HEAVY DUTY DRY VAC component of the Heavy Duty HEPA Vac.  The Heavy Duty HEPA Vac features the same hardened alloy construction of the Heavy Duty Dry Vac.  This alloy holds up to abrasive materials such as garnet, crushed glass, sand or hard materials like stainless steel chips, pipe plugs, or brass piping caps.  We tested the conveying power of the Heavy Duty Dry Vac, it moved 32 pounds per minute of steel shot blasting media, 146% percent more than a standard Chip Vac.  With all this vacuuming power, it still maintains a surprisingly quiet 82 dBA of sound level.

The Heavy Duty HEPA Vac would be the perfect item to clean out that clogged filtration system, or to clean up that spilled kitty litter that will clog up a standard electrical vacuum. It will not blow tiny particulate all over your shop and it can help protect your personnel from airborne particulate.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

EXAIR Heavy Duty Line Vac Re-Loads Rainfall Sander

Published on by Neal RakerLeave a comment

In the world of lost wax casting a wax pattern is created and then fused to a wax runner system along with multiples of other patterns or perhaps the same pattern. Once the “tree” of wax patterns is created, the tree is coated with a fine material to reproduce fine details in the pattern and is then “stuccoed” with a coarse, ceramic material. It is this application of the coarse ceramic material process with which my most recent customer needed help. It was not so much the application of the ceramic material to the wax pattern but the refilling of the rainfall sander which is the tool that actually applies the ceramic to the patterns. Below is a photo of a rainfall sander for your reference.

As you can see a fine, water fall-like flow of sand dropping down from above provides the means for the “stuccoing” process.

rain fall sanderHDLV

The problem is that the hoppers for these machines can be in excess of 7 feet above the floor and require replenishing. The idea is to put just the right amount of material into the hopper without over-filling which has been a problem in the past with the customer dumping by hand over-head.

The solution the customer was looking for was the 1-1/2” Heavy Duty Line Vac to be used in a moveable cart-based hopper filling tool with a gallows-type over arm which can be placed above the hopper of each machine to provide the metered filling.

The reasons for picking the Heavy Duty version of the EXAIR Line Vac was for its robust resistance to abrasion from high speed materials moving through the throat area. Heavy Duty Line Vac is made of a high grade, tool steel with a proprietary surface treatment to harden the material even further to make the unit highly resistant to abrasion. The Heavy Duty Line Vac has been used with such materials as silica sand, ground glass and ground garnet for hopper replenishment in abrasive blasting applications, so it could handle the stucco material quite nicely. The higher conveying capacity of the Heavy Duty Line Vac also made quick work of the material being conveyed to make for unobtrusive service.

Neal Raker, EXAIR
nealraker@exair.com