Vortex Tubes Cool a UV Scanner

Copper smelting furnace

Safety is important when it comes to gas furnaces; and with large ovens, equipment is used to protect workers and equipment.  A copper company was using natural gas for smelting, and they had a UV scanner to monitor the flames.  If the burners go out, the scanner will turn off the gas valves to stop a potential explosion.   As with many instruments, it is important to keep the electronics cool for proper measurements.  In this case, they were having issues with accuracy from the high heat.  They contacted EXAIR for a solution. 

Air path flow for UV scanner

With their UV scanner, it was designed for a “cooling” device already.  This was basically compressed air that would blow around the instrument.  Because of the location, the compressed air was heating up to 125oF (52oC).  This heat would not cool the scanner properly, and it was causing unreliable readings and premature shutdowns.  They gave me the design specifications, and the scanner required 3.2 SCFM (90 SLPM) of air at atmospheric pressure with a maximum of 77oF (25oC).  I mentioned that we had the perfect solution to keep the UV scanner cool and operational; the EXAIR Vortex Tube.   This product can take elevated temperatures of compressed air and reduce it to lower temperatures.   It is a low cost, reliable, maintenance-free solution that uses compressed air to produce cold air as low as -50oF (-46oC).  With a range of cooling capacities from 135 BTU/hr to 10,200 BTU/hr, I was sure that we could meet the requirements for proper cooling. 

To determine the correct size, I had to look at the temperature drop and the flow requirement.  The temperature had to decrease from the 125oF (52oC) incoming compressed air to at least 77oF (25oC).  This would equate to a 48oF (27oC) temperature drop.  The other requirement was the amount of air flow, 3.2 SCFM (90 SLPM).  With the chart below, I see that we are able to get a 52oF (29oC) temperature drop at a 70% Cold Fraction and 40 PSIG (2.8 bar) inlet pressure.  EXAIR Vortex Tubes are very adjustable to get different outlet temperatures by changing the inlet pressure and the Cold Fraction.  The Cold Fraction (CF) is the amount of air that will be coming out the cold end.  With a 70% CF, that means that the adjusting screw on the hot end of the Vortex Tube is turned to allow 70% of the incoming compressed air to go out the cold end.  So, with that information, we can size to the correct model. 

In comparing the above information to the catalog data at 100 PSIG (6.9 bar), we have to consider the difference in absolute pressures.  With an atmospheric pressure of 14.5 PSIG (1 bar), the equation looks like this:

Qv = (Qc / CF) * (Pc + 14.5 PSIA) / (Ps + 14.5 PSIA)

Qv – Catalog Vortex Tube flow (SCFM)

Qc – Cold Air Flow (SCFM)

CF – Cold Fraction

Pc – Catalog Pressure – 100 PSIG

Ps – Supply Pressure – PSIG (Chart above)

From this equation, we can solve for the required Vortex Tube: 

                Qv = (3.2 SCFM / 0.7) * (100 + 14.5 PSIA) / (40 + 14.5 PSIA) = 9.6 SCFM. 

In looking at the catalog data, I recommended our model HT3210 Vortex Tube which uses 10 SCFM of compressed air at 100 PSIG.  The HT prefix is for our High Temperature models for use in temperatures in the range of 125oF to 200oF (52oC to 93oC).  So, after installing, the Vortex Tube was able to supply 73oF (23oC) air at a flow of 3.3 SCFM (94 SLPM); keeping the UV scanner reading correctly and accurately. 

Sometimes compressed air by itself is not enough to “cool” your instruments.  The EXAIR Vortex Tubes can reduce the temperature of your compressed air to very cold temperatures.  If you believe that your measuring equipment is being affected by elevated temperatures like the company above, you can contact an Application Engineer at EXAIR to find the correct solution for you. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Flat Super Air Nozzle vs. Open Pipe ROI

The EXAIR Flat Super Air Nozzles are manufactured to blow a wide forceful stream of air.  Their patented design creates a high velocity, laminar air stream with minimal air consumption and low noise.  They come in two widths; 1” (25mm) and 2” (51mm).  EXAIR offers a standard Flat Super Air Nozzle and a High Force Flat Super Air Nozzle in two different materials, zinc-aluminum alloy and 316 stainless steel.  And with a metal construction, breakage is not a concern and performance are not sacrificed even in the harshest of environments. 

The unique patented shims inside the EXAIR Flat Super Air Nozzles will give you three improvements to the design and function.  First, they come in different thickness to create a wide range of forces.  In conjunction with a regulator, you can “dial” in the correct amount of force from a breeze to a blast without overusing your air compressor.  The patented design also allows an even flow across the entire width of the air nozzle.  Lastly, they help to entrain the free ambient air; so that less compressed air is required.  The high efficiency design will save you money.  The EXAIR Flat Super Air Nozzles are effective in uniform blowing with safety and efficiency in mind.

2″ Flat Super Air Nozzle

To expand more on force adjustments with the Flat Super Air Nozzles, EXAIR has an easy way to change the shim to better suit your application.  You can increase or decrease the force of the nozzle by just removing two screws and changing the thickness of the shim inside.  EXAIR offers a variety pack called a Shim Set to give you a wide range of forces with the nozzles.  For the standard Flat Super Air Nozzle, they come stock with a 0.015” (0.38mm) shim for both the 1” and 2” sizes.  The corresponding Shim Sets will include a 0.005” (0.13mm), 0.010” (0.25mm), and 0.020” (0.51mm) shim.  The High Force Flat Super Air Nozzles will come standard with a 0.025” (0.64mm) shim; and the Shim Set will include a 0.020” (0.51mm) and 0.030” (0.76mm) thick shim.  This is a unique feature as most competitive flat nozzles do not allow you to do this.  The chart below corresponds the appropriate Shim Set to the Flat Super Air Nozzle.

Not only are they safe, and easily adjustable they can help save compressed air vs using a open ended pipe!

For example, let’s look at the average operating costs for a single 1/4″ open copper tube. (If you don’t know you current energy costs, a reasonable average to use is $ 0.25 per every 1,000 SCF used, based on $ 0.08/kWh.

1/4″ Copper tube

A single 1/4″ open copper tube consumes 33 SCFM @ 80 PSIG and costs roughly $ 0.50 per hour to operate. (33 SCF x 60 minutes x $ 0.25 / 1,000 = $ 0.50). For an 8 hour shift, the total cost would be $ 4.00 ($ 0.50 x 8 hours = $ 4.00).

If we were to replace the 1/4″ open copper tube with our Model # 1122 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet, the air consumption would be reduced to 21.8 SCFM @ 80 PSIG. This may not seem like much of an air usage reduction, but when you look at the monetary, total cost of ownership for purchasing and operating the nozzle, the savings can quickly add up.

The operating cost for a 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet is $ 0.33 per hour (21.8 SCF x 60 minutes x $ 0.25 / 1,000 = $ .033) or $ 2.64 per 8 hour shift ($ 0.33 x 8 hours = $ 2.64).

We can now compare the operational cost between the 2 devices:

1/4″ open copper tube operating costs:
$ 0.50 per hour
$ 4.00 per day (8 hours)

2″ Flat Super Air Nozzle operating costs:
$ 0.33 per hour
$ 2.64 per day (8 hours)

Cost Savings:
$ 4.00 / day (open copper tube) –  $ 2.64 / day (2″ Flat Super Air Nozzle) = $ 1.36 savings per day

The Model # 1122 2″ Flat Super Air Nozzle has a list price $ 67.00 USD.

ROI or Return On Investment calculation:
$ 67.00 (Cost) / $ 1.36 (savings per day) = 49.26 days.

The 2″ Flat Super Air Nozzle would pay for itself in just over 49 days in operation. This is the savings for replacing just ONE 1/4″ open copper tube with an engineered solution! In most industrial plants, there could be several of these which presents even more opportunities to reduce the overall operational costs.

Our focus here at EXAIR is to improve the overall efficiency of industrial compressed air operating processes and point of use compressed air operated products. If you are looking to reduce compressed air usage in your facility, contact an application engineer and let us help you optimize your current system.

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

Replacing a 1/4″ Open Copper Tube With a 2″ Flat Super Air Nozzle Leads To Quick ROI

The generation of compressed air accounts for approximately 1/3 of all energy costs in an industrial facility and up to 30% of that compressed air is wasted through inefficient operation. Open pipes or homemade blowoffs waste a ton of compressed air, resulting in high operating costs. By replacing these devices with an energy efficient, engineered solution, you can reduce this waste and dramatically cut energy costs.

For example, let’s look at the average operating costs for a single 1/4″ open copper tube. (If you don’t know you current energy costs, a reasonable average to use is $ 0.25 per every 1,000 SCF used, based on $ 0.08/kWh.

1/4″ Copper tube

A single 1/4″ open copper tube consumes 33 SCFM @ 80 PSIG and costs roughly $ 0.50 per hour to operate. (33 SCF x 60 minutes x $ 0.25 / 1,000 = $ 0.50). For an 8 hour shift, the total cost would be $ 4.00 ($ 0.50 x 8 hours = $ 4.00).

If we were to replace the 1/4″ open copper tube with our Model # 1122 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet, the air consumption would be reduced to 21.8 SCFM @ 80 PSIG. This may not seem like much of an air usage reduction, but when you look at the monetary, total cost of ownership for purchasing and operating the nozzle, the savings can quickly add up.

2″ Flat Super Air Nozzle

The operating cost for a 2″ Flat Super Air Nozzle with 1/4″ FNPT inlet is $ 0.33 per hour (21.8 SCF x 60 minutes x $ 0.25 / 1,000 = $ .033) or $ 2.64 per 8 hour shift ($ 0.33 x 8 hours = $ 2.64).

We can now compare the operational cost between the 2 devices:

1/4″ open copper tube operating costs:
$ 0.50 per hour
$ 4.00 per day (8 hours)

2″ Flat Super Air Nozzle operating costs:
$ 0.33 per hour
$ 2.64 per day (8 hours)

Cost Savings:
$ 4.00 / day (open copper tube) –  $ 2.64 / day (2″ Flat Super Air Nozzle) = $ 1.36 savings per day

The Model # 1122 2″ Flat Super Air Nozzle has a list price $ 67.00 USD.

ROI or Return On Investment calculation:
$ 67.00 (Cost) / $ 1.36 (savings per day) = 49.26 days.

The 2″ Flat Super Air Nozzle would pay for itself in just over 49 days in operation. This is the savings for replacing just ONE 1/4″ open copper tube with an engineered solution! In most industrial plants, there could be several of these which presents even more opportunities to reduce the overall operational costs.

Our focus here at EXAIR is to improve the overall efficiency of industrial compressed air operating processes and point of use compressed air operated products. If you are looking to reduce compressed air usage in your facility, contact an application engineer and let us help you optimize your current system.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Cooling Copper Welds with an Adjustable Spot Cooler

In the video above, two strands of braided copper wire are welded together in an automated process.  As the wire travels through the machine, it is heated to 600-800°C (~1100-1500°F) to fuse together, cooled, then cut into strips.  The original setup (shown in the video), was to use water to cool the copper after welding, but this proved to be undesired because residual water was left in the copper braid, leading to quality control problems.  But without proper cooling, the heat created during welding would stress the copper and reduce the quality of the product.

In an effort to remove the liquid cooling from the application, the customer was considering whether a Vortex Tube solution would be able to remove enough heat from the copper in the required timeframe of 10-15 seconds.  The end goal was to maintain the production level of the process, but to remove liquid from the application, and cool the welded copper to 200°C (~400°F).  In order to allow for on-the-fly adjustment, an Adjustable Spot Cooler was chosen for testing purposes.

20160907_081646
This setup surrounded the welded copper with freezing cold air

To configure this setup, the cold outlet of the Adjustable Spot Cooler was fed into a tube surrounding the copper braids (shown above).  This tube surrounded the welded copper with below freezing air to remove the heat and cool the copper.

before-and-after
Results of installing the Adjustable Spot Cooler

The results of this setup are shown above.  On the left is the output of the process without cooling from the Adjustable Spot Cooler (copper of this quality fails quality control checks), and on the right is the output from the same process, but with cooling from the Adjustable Spot Cooler.  The copper on the right is welded, cooled, and will pass quality control checks – all without the use of liquid cooling.

Removing liquid cooling from this application increases the quality of this production process, all while maintaining the same production levels.  And, this customer is now considering the use of a “stronger” Vortex Tube solution which may provide for increases in the throughput of the production process.

To discuss a similar application, or any application in need of a compressed-air based solution, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE