Receiver Tank Calculations

Receiver Tank

My colleague, Lee Evans, wrote a blog about calculating the size of receiver tanks within a compressor air system.  (You can read it here: Receiver Tank Principle and Calculations).  But, what if you want to use them in remote areas or in emergency cases?  During these situations, the air compressor is not putting any additional compressed air into the tank.  But, we still have potential energy stored inside the tanks similar to a capacitor that has stored voltage in an electrical system.  In this blog, I will show how you can calculate the size of receiver tanks for applications that are remote or for emergency systems.

From Lee Evans’ blog, Equation 1 can be adjusted to remove the input capacity from an air compressor.  This value is Cap below.  During air compressor shutdowns or after being filled and removed, this value becomes zero.

Receiver tank capacity formula (Equation 1)

V = T * (C – Cap) * (Pa) / (P1-P2)

V – Volume of receiver tank (cubic feet)

T – Time interval (minutes)

C – Air requirement of demand (cubic feet per minute)

Cap – Compressor capacity (cubic feet per minute)

Pa – Absolute atmospheric pressure (PSIA)

P1 – Tank pressure (PSIG)

P2 = minimum tank pressure (PSIG)

 

Making Cap = 0, the new equation for this type of receiver tank now becomes Equation 2.

Receiver tank capacity formula (Equation 2)

V = T * C * (Pa) / (P1-P2)

With Equation 2, we can calculate the required volume of a receiver tank after it has been pre-charged.  For example, EXAIR created a special Air Amplifier to remove toxic fumes from an oven.  The Air Amplifier was positioned in the exhaust stack and would only operate during power failures.  In this situation, product was being baked in an oven.  The material had toxic chemicals that had to cross-link to harden.  If the power would go out, then the product in the oven would be discarded, but the toxic fumes had to be removed.  What also doesn’t work during power outages is the air compressor.  So, they needed to have a receiver tank with enough volume to store compressed air.  From the volume of the oven, we calculated that they need the special Air Amplifier to operate for 6 minutes.  The compressed air system was operating at 110 PSIG, and the Air Amplifier required an average air flow of 10 cubic feet per minute from the range of 110 PSIG to 0 PSIG.  We are able to calculate the required receiver volume to ensure that the toxic fumes are evacuated from the oven in Equation 2.

Receiver tank capacity formula (Equation 2)

V = T * C * Pa / (P1 – P2)

V = 6 minutes * 10 cubic feet per minute * 14.7 PSIA / (110 PSIG – 0 PSIG)

V = 8 cubic feet.

Receiver tanks are more commonly sized in gallons.  In converting 8 cubic feet to gallons, we get a 60-Gallon Receiver Tank.  EXAIR recommended the model 9500-60 to be used near the oven to operate the special Air Amplifier during power outage.

Another way to look at Equation 2 is to create a timing equation.  If the volume of the tank is known, we can calculate how long a system will last.  In this example for scuba diving, we can use this information to configure the amount of time that a tank will last.  The diver has a 0.39 cubic feet tank at a pressure of 3,000 PSIG.  I will use a standard Surface Consumption Rate, SCR, at 0.8 cubic feet per minute.  If we stop the test when the tank reaches a pressure of 1,000 PSIG, we can calculate the time by using Equation 3.

Receiver tank timing formula (Equation 3):

T = V * (P1 – P2) / (C * Pa)

T – Time interval (minutes)

V – Volume of receiver tank (cubic feet)

C – Air demand (cubic feet per minute)

Pa – Absolute atmospheric pressure (PSIA)

P1 – Initial tank pressure (PSIG)

P2 – Ending tank pressure (PSIG)

By placing the values in the Equation 3, we can calculate the time to go from 3,000 PSIG to 1,000 PSIG by breathing normal at the surface.

T = 0.39 cubic feet * (3,000 PSIG – 1,000 PSIG) / (0.8 cubic feet per minute * 14.7 PSIA)

T = 66 minutes.

What happens if the diver goes into deeper water?  The atmospheric pressure, Pa, changes.  If the diver goes to 100 feet below the surface, this is roughly 3 atmospheres or (3 * 14.7) = 44.1 PSIA.  If we use the same conditions above except at 100 feet below, the time will change by a third, or in looking at Equation 3:

T = 0.39 cubic feet * (3,000 PSIG – 1,000 PSIG) / (0.8 cubic feet per minute * 44.1 PSIA)

T = 22 minutes. 

If you have any questions about using a receiver tank in your application, you can contact an EXAIR Application Engineer.  We will be happy to solve for the proper volume or time needed for your application.

 

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

Super Air Knife Cleans Baking Pans

A few weeks back I was contacted by a large baking company who was looking for a better way to pre-clean their cake and muffin pans before sending them to a wash cycle. After the pans exit the oven, an operator places the baked goods on a cooling conveyor then uses an air gun to blow out the residual crumbs. The pans are then placed on a separate conveyor and sent through a washer. The manual operation was taking a lot of extra time which resulted in reduced production.

Muffin Pan

After further discussion, I recommended they use our 24″ Super Air Knife. The Super Air Knife produces an even, high velocity curtain of air across the entire length of the knife which would provide a uniform blowoff of the pans, eliminating the manual cleaning.  Super Air Knives are extremely efficient and quiet. Operating at 80 PSIG, using a 40:1 amplification rate of entrained ambient air to compressed air consumed, they require only 2.9 SCFM per inch of knife length while maintaining a low sound level of only 69 dBA and produce a velocity of 11,800 feet per minute.

Efficient way to clean, dry or cool parts, webs or conveyors.

The Super Air Knives are available in lengths from 3″ up to 108″ in single-piece construction and offered in aluminum, 303ss or 316ss construction, they are the perfect choice for small scale or wide coverage blowoff applications. To discuss a particular application or for help selecting the best EXAIR product to fit your need, contact an application engineer at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Muffins Anyone? photo courtesy of Amy via creative commons license.

Reversible Drum Vac Quickly Empties Sump In Close Quarters

I had the pleasure of talking with an operator in a power generating plant recently. A small sump, in a hard-to-access location, needed to be emptied periodically, or it would overflow and make a big mess. They didn’t have room for a “great big” (his words) 30 or 55 gallon drum, and it was difficult to use an electric shop vac because there wasn’t an outlet nearby (it’s a very humid location in the steam plant) so they had to rig an long extension cord through a doorway and down to the lower mezzanine.

They DO have compressed air available…in fact, there was an unused port on a manifold that supplied other pneumatic equipment, right next to the sump. He thought it sounded like an ideal application for the Mini Reversible Drum Vac.

And it was. They put a Model 6196-5 Mini Reversible Drum Vac System on the floor, next to the sump, and empty it (usually 1-2 gallons) on the night shift. They also got a 6569-20 20ft Vacuum Hose, which they use to pump the drum contents into an internal drain system.

Reversible Drum Vac systems are available from 5 to 110 gallon capacity

No more hassles with the electric shop vac and extension cord. No more overflow messes. The most they have to do now is change to the 20ft hose when they empty the drum.

If you’d like to find out how an EXAIR Intelligent Compressed Air Product can make your life easier, give me a call.

EXAIR Industrial Vacuums: Dry Vacuums

Our Industrial Housekeeping vacuums utilize compressed air energy to create a powerful and effective vacuum capable of with standing the harshest of environments. These vacuums have no moving parts to wear out or replace, run quietly and are built to be placed upon your own drum or may be purchased with a drum.

EXAIR has three dry/solid vacuum systems available they are the Chip Vac, Heavy Duty Dry Vac and the Heavy Duty HEPA Vac.

The EXAIR Chip Vac picks up wet or dry chips and delivers them directly into an ordinary open-top drum.  The Chip Vac is used to clean chips from fixtures, floors and work surfaces of machining centers, lathes, saws, mills and other industrial equipment.  The Chip Vac is the ideal choice for quick and efficient cleaning.  The Chip Vac can also be used to vacuum wood or plastic chips and can be used occasionally for dusty materials since it incorporates a filter bag to keep the surrounding air clean.

The 30, 55 & 110 Gallon Chip Vac’s consume 40 SCFM @ 80 PSI while the 5 Gallon size consumes 33 SCFM @ 80 PSI.  All 4 models are rated at a super quiet 77 dBA!

chipvac_family
5, 30, 55, and 110 Gallon Chip Vacs

The Heavy Duty Dry Vac like the Chip Vac can attach to ordinary open-top drums.  Designed to withstand tough industrial environments the proprietary hardened alloy pump deliver powerful performance with superior abrasion resistance.  They are used for a wide variety of applications that include abrasive materials such as steel shot, garnet, metal chips and sand!  Please know that while very powerful it is still suitable for general applications such as vacuuming floors, machines, work stations and industrial equipment.

The 30, 55 & 110 Gallon Heavy Duty Dry Vac’s consume 68 SCFM @ 80 PSI and have a sound level of 82 dBA.

6397
Available in 30, 55 & 110 Gallon Sizes

Finally the Heavy Duty HEPA Vac has the added benefit of the HEPA quality filter system.  Filtration per IEST-RP-CC-007 to 99.97% minimum filtration at the 0.3 micron level ensures performance meets the needed criteria.  Like the Chip Vac and the Heavy Duty Dry Vac it will attach to ordinary open top drums as well.

The 30, 55 & 110 Gallon Heavy Duty HEPA Vac’s consume 68 SCFM @ 80 PSI and have a sound level of 82 dBA.

6399
Available in 30, 55 & 110 Gallon Sizes

When you look at the EXAIR vacuum producing units, you will notice there is not an electrical cord.  That is because the EXAIR Industrial Housekeeping Products utilize compressed air for operation, therefore they do not have the same issues with wear, breakdown and failures as electrical type vacuums. Quite simply there are no moving parts in the vacuum units to wear out or break.  They are maintenance free, just make sure the air supply is clean & dry, and they will operate for a long time due to the fact that there are no motors and bearings to wear out and no impellers to clog.

If you would like to discuss Industrial Housekeeping or any EXAIR product,  I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Cabinet Coolers 101

We here at EXAIR always know when summer is approaching, as phone calls and orders for the Cabinet Cooler Systems start to kick into high gear.  After those first few hot days in late spring, it is common for panels and electrical enclosures to overheat due to faulty air conditioning units, fans that are not working, or lack of a cooling system in general.

Time for us to sharpen our pencils and be ready to help! Our Cabinet Coolers are in stock and ready to solve your overheating problems with same day shipping on orders we receive by 3pm. If you need assistance choosing your Cabinet Cooler Solution, Contact an Application Engineer today!

The Cabinet Cooler System is a low cost, reliable way to cool and purge electronic control panels.  We recently hosted a Webinar on the systems, and it is available for review (click picture below)  webinar-on-demand

EXAIR Cabinet Coolers incorporate the vortex tube technology to produce cold air from compressed air, all with no moving parts.

Below shows the basics of how the Cabinet Cooler is able to provide cooling to an enclosure.  Compressed air enters the vortex tube based system, and (2) streams of air are created, one hot and one cold. The hot air is muffled and exhausted through the vortex tube exhaust.  The cold air is discharged into the cabinet through the Cold Air Distribution Kit and routed throughout the enclosure. The cold air absorbs heat from the cabinet, and the hotter air rises to the top of the cabinet where it exits to atmosphere under a slight pressure. Only the cool, clean, dry air enters the cabinet – no dirty, hot humid outside air is ever allowed into the cabinet!

HowCCWorks
How the EXAIR Cabinet Cooler System Works

EXAIR offers Cabinet Cooler Systems for cabinets and enclosures to maintain a NEMA rating of NEMA 12 (dust tight, oil-tight), NEMA 4 (dust tight, oil-tight, splash resistant, indoor/outdoor service) and NEMA 4X (same as NEMA 4, but constructed of stainless steel for food service and corrosive environments.

Cabinet Cooler Systems can be configured to run in a Continuous Operation or with Thermostat control. Thermostat control is the most efficient way to operate a Cabinet Cooler.  They save air by activating the cooler only when the internal temperature reaches the preset level, and are the best option when fluctuating heat loads are caused by environmental or seasonal changes. The thermostat is preset at 95°F (35°C) and is easily adjusted.

Another option is the ETC Electronic Temperature Control, a digital temperature control unit for precise setting and monitoring of enclosure conditions. An LED readout displays the internal temperature, and the use of quick response thermocouple provides real time, accurate measurements. The controller has easy to use buttons to raise or lower the desired cabinet temperature set-point.

48xx-ETC120
EXAIR NEMA 4X 316SS Cabinet Cooler System with Electronic Temperature Control installed on control panel in a pharmaceutical plant.

 

Other Special Cabinet Cooler considerations are:

  • High Temperature –  for ambient temperatures of 125°F to 200 °F – for use near furnaces, ovens, etc.
  • Non-Hazardous Purge – ideal for dirty areas where contaminants might normally pass through small holes or conduits. A small amount of air (1 SCFM) is passed through the cooler when the solenoid is in the closed position, providing a slight positive pressure within the cabinet.
  • Type 316 Stainless Steel – suitable for food service, pharmaceutical, and harsh and corrosive environments.

If you have any questions about Cabinet Coolers or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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EXAIR Cabinet Coolers for a Food and Beverage Company

316SS Electrical Panels

A food and beverage company had 316SS NEMA 4X (IP66) electrical panels inside their facility.  The reason for the stainless-steel construction and NEMA 4X or IP66 rating was for the periodic washdowns with an aggressive cleaner.

This particular company had a bottling process and inside each panel, sensitive electrical components would control the operation of the system.  The panels were fitted with Freon type air conditioners to keep the electrical components cool.  One day, they had an A/C unit that failed, and it shut down their system for half a day.  For a bottling company, a shutdown for this long stopped many bottles from being processed which costed much money from loss of production.

They had four panels that were setup similar right next to each other.  They were fitted with 1,700 BTU/hr freon system on each panel.  In this situation, one of the refrigerant compressors failed.  They had to hire a mechanical serviceman with a license to work on Freon systems.  Because of the length of time to get their system restarted, they were losing money every minute.  This emergency call really hindered the entire bottling process.  In fear of another shutdown, they contacted EXAIR to see if we could help them.

Even with constant maintenance, the life span of a Freon system is only around five years.  (It can be even shorter if preventative maintenance is not scheduled regularly). Any mechanical system with moving parts will wear out and fail.  EXAIR Cabinet Coolers use the power of a Vortex Tube which only needs compressed air to generate cold air.  With no moving parts to wear or unsafe Freon to leak, they are designed to keep your electrical components cool and operating for a very long time.  Trying to predict failures with refrigerant systems is very difficult to determine; but, with the EXAIR Cabinet Cooler Systems, it takes that worry away.

EXAIR NEMA Type 4X Cabinet Cooler System

EXAIR Cabinet Cooler Systems are manufactured in a variety of options and types to meet different application requirements.  For the food and beverage company above, I recommended the model 4830SS-316 Cabinet Cooler System to replace each of the A/C refrigeration systems.  The model 4830SS-316 would meet the cooling requirement with 2,000 BTU/hr capacity, the NEMA 4X (IP66) rating of the panel, and the 316SS construction to withstand washdowns.  The complete system includes the Cabinet Cooler, a filter, cold air distribution kit, a thermostat and a solenoid valve.  The thermostat is preset at 95 deg. F (35 deg. C), and it operates a solenoid valve to only turn on when cooling is needed.  EXAIR has this model in stock as well as many others for quick delivery, reducing any downtime.  After the installation of the Cabinet Coolers onto the panels, the worry of production stoppage due to a failure with an A/C system was alleviated.

Maintenance departments have many concerns in keeping a system running smoothly and uninterrupted.  Why add additional worries with coolant based panel coolers?  If you have electrical panels that can stop your operation like the bottling company above, an EXAIR Cabinet Cooler will be a reliable solution.  You can fill out the Cabinet Cooler Sizing Guide and an Application Engineer can determine the best model for you.

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

Product Overview: No Drip External Mix Atomizing Spray Nozzles

EXAIR’s Atomizing Nozzles are commonly used to clean, cool or coat parts as well as humidification or to control dust. They are constructed of 303ss, providing superior corrosion resistance and are able to withstand temperature up to 400°F (204°C).

The Atomizing Nozzles are separated into 3 categories – Internal Mix, External Mix and Siphon Fed.

For today’s topic, we will focus on the No Drip External Mix Atomizing Nozzles.

No Drip External Mix Atomizing Nozzles provide the highest flow rates

The External Mix Atomizing Spray Nozzles require a pressurized liquid source and compressed air source to produce a mist of atomized liquid. With the liquid and air being mixed external to the nozzle, they are able to handle higher viscosity fluids above 300 cP.

Our patented No Drip feature positively stops the liquid flow when the supply air pressure drops below 20 PSIG for 1/8″ NPT Nozzles or 30 PSIG for the 1/4″ or 1/2″ NPT. By incorporating this feature into the design, it eliminates the need for any additional valves or supply lines.

Available flow rates range from 2 GPH for our Model # EF9010SS 1/8″ No Drip External Mix Narrow Angle Flat Fan Pattern and up to 303 GPH for the Model # EF6010SS 1/2″ No Drip External Mix Narrow Angle Flat Fan Pattern.

When making a selection, there are 5 common considerations to take into account:

  1. How much liquid flow do I need?
  2. Is the liquid pressurized?
  3. What is the viscosity of the liquid?
  4. How wide of an area needs to be treated?
  5. What type of spray pattern fits the application?

If you have an application requiring a fine mist of atomized liquid or if you’d like to discuss another product or application, contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN