Super Air Knife Replaces a Blower-type Air Knife and Saves Money Annually

Sheet washing system

A sheet metal company made thin stainless steel sheets in their process.   Before the sheets were rolled up, it went through a washing system.  Two blower-type air knives were mounted after the wash cycle to remove the residual water from the surface.  They purchased the blower-style air knives under the belief that they would save money by not using compressed air.  They found out quickly that it was not a true statement especially when it comes to the total cost of ownership.

With the dirty environment at their facility, the inlet filter on the blower was getting plugged.  The blower motor would heat up from the filter being restricted.  After eight months of service, the blower motor failed due to excessive heat.  The replacement was very costly, and it created a production stoppage for an entire day.  The manufacturer of the blower-type air knife recommended that the filter should be changed every month instead of quarterly.  This recommendation increased the monthly budget for the blower system, but they did not want to replace the blower motor again.  Instead of a quarterly stop in production for maintenance, the washing system had to be stopped every month for filter change-out.   They decided to contact EXAIR to see if their concept of “saving money” with the blower-type air knife was valid.

To better explain the concept, I divided the comparisons into different categories explaining the details between the Super Air Knife and the blower system.

  1. Initial Cost:
    • Blower System – They are an expensive set up when you have to include a blower, ducting, and a knife. To have any flexibility, a control panel with a VFD will be needed.
    • Super Air Knife – It is a fraction of the cost. With their system above, we were roughly 1/4 the cost.  A capital expense would not be required for ordering two Super Air Knives to remove the water from the stainless steel sheets.
  1. Maintenance:
    • Blower System – The intake filter had to be changed every month, and the customer estimated a cost of $150.00 each. The motor and belt also had to be checked quarterly as a preventive maintenance.  Being that the blower motor is a mechanical device, the bearings and belts will wear and have to be replaced.  Without proper maintenance, things can break prematurely.  This customer had to already replace the motor in their system.
    • Super Air Knife – They do not have any moving parts to wear out, and they are not affected by the dirty environment. Only compressed air is needed to operate.  The maintenance requirement is to change the compressed air filter once a year.  The annual price for the replacement filter is less than $35.00.
  2. Compressed air usage:
    • Blower System – This device does not require any compressed air to operate, but it does use an electric motor. For this customer, they had a 7.5KW blower motor.  With the inherent designs of blower-type air knives, they have reduced blowing forces and turbulent air flows.  This combination required maximum power output on the 7.5KW blower motor.
    • Super Air Knife –With their unique design, it has one of the highest efficiencies in the market place. It can entrain 40 parts of ambient “free” air with every 1 part of compressed air.  With laminar flow and the power of compressed air, the Super Air Knives can be used at a much lower air pressure.  To compare with the electric blower motor above, the Super Air Knives only required 11KW of compressor power to operate.
  3. Noise:
    • Blower System – With the turbulent air flow, the blower units are very loud. It can have a sound level near 93 dBA.  If operators are working near the system, they would require PPE for hearing.  The cost for proper hearing equipment and the training for the operators will add more cost with using blower systems.
    • Super Air Knife – These units are very quiet. Even at an elevated pressure, the sound level is only 72 dBA at 100 PSIG.  This level is below the maximum noise exposure for hearing safety as marked in OSHA 29CFR 1910.95(a).

 

I tabulated the annual cost comparison and shared it with the customer to better explain the total cost of ownership.  After reviewing the information, they decided to try two pieces of the model 110230 Super Air Knife Kits.  When they replaced the blower-type air knives, the customer did share some additional information.  First, they were amazed at the ease of installation.  The blower-type air knives had to be electrically wired; floor space was sacrificed for the blower; the connection hoses were large and bulky; and the mounting was cumbersome.  The customer also noticed the amount of power that was created by the Super Air Knives.  They were able to increase the feed rates of the stainless steel sheets if they wanted and still keep the surface dry.  This gave them flexibility in their production system.  And of course, the maintenance time and cost were practically eliminated.  Compressed air is expensive, but if you use EXAIR products, you can use the compressed air very efficiently.  As noticed in the tabulation above, the total cost of ownership is very expensive for the blower-type air knives as compared to the Super Air Knives.  You can contact an Application Engineer at EXAIR if you want to discuss further the benefits of using the Super Air Knives.

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

Cleaning the Gen4 Static Eliminators

It has been over two years since EXAIR first brought our Gen4 Static Eliminators to market with improved performance, materials and durability.  The new design features continue to provide our customers with reliable, rugged and problem solving static eliminators.

More recently our Gen4 product line was completed by integrating these same beneficial features in the Gen4 Ionizing Bars, Gen4 Super Ion Air Knives, and Gen4 Standard Ion Air Knives.

There are two common ways that a Static Eliminator will start to underperform; contamination buildup and point degradation.  To create ions from a metal point, a high voltage is needed.  With 5,000 volts forcing its way into a confined area, the energy behind making an ion creates a corona field.  Any contamination near or around that point will produce a small amount of charred material.  The more contamination in the surrounding area, the faster the buildup will occur. Once a sharp point is coated, the ion production begins to decrease.

The other issue is with metal point degradation.  With the cycle of heating and cooling, the material will start to lose the sharpness of the point over time.  Like a wick used in a candle, you lose a little bit each time.  For both methods above, once the point sharpness is reduced, the dissipation time to remove static starts to increase.

For any “forensics” analysis with the Static Eliminators, you should have a model 7905 Static Meter.  Besides viewing the ion points, the Static Meter can help determine the severity of the function of the ion points.  If cleaning is required, you can use a soft-bristled brush to remove any charred contamination from the point and the base area.  Make sure that the power is turned off before cleaning.  For resistor-based Static Eliminators, the metal ion pins are replaceable.  This is model 901188.  This added feature makes a cost-effective way to keeping the points sharp, and the Static Eliminators like new.  The video below shows how to clean and replace the ion points.

Contact any of our Application Engineers if you have any additional questions about cleaning, about a new application or about potential solutions to static related problems.

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

What is Laminar Flow and Turbulent Flow?

Fluid mechanics is the field that studies the properties of fluids in various states.  There are two areas, fluid statics and fluid dynamics.  Fluid dynamics studies the forces in a fluid, either as a liquid or a gas, during motion.  Osborne Reynolds, an Irish innovator, popularized this dynamic with a dimensionless number, Reyonlds number. This number can indicate the different states that the fluid is moving; either in laminar flow or turbulent flow.  The equation below shows the relationship between the inertial forces of the fluid as compared to the viscous forces.  Reynolds number, Re, can be calculated by Equation 1:

Equation 1:  Re = V * Dh/u

Re – Reynolds Number (no dimensions)

V – Velocity (feet/sec or meters/sec)

Dh – hydraulic diameter (feet or meters)

u – Kinematic Viscosity (feet^2/sec or meter^2/sec)

The value of Re will mark the region in which the fluid (liquid or gas) is moving.  If the Reynolds number, Re, is below 2300, then it is considered to be laminar (streamline and predictable).  If Re is greater than 4000, then the fluid is considered to be turbulent (chaotic and violent).  The area between these two numbers is called the transitional area where you can have small eddy currents and some non-linear velocities.  To better show the differences between each state, I have a picture below that shows water flowing from a drain pipe into a channel.  The water in the channel is loud and disorderly; traveling in different directions, even upstream.  With the high speed coming from the drain pipe, the inertial forces are greater than the viscous forces of the water.  The Reynolds number is larger than 4000 which indicates turbulent flow.  As the water travels into the mouth of the river after the channel, the waves transform from a disorderly mess into a more uniform stream.  This is the transitional region.  A bit further downstream, the stream becomes calm and quiet, flowing in the same direction.  This is the laminar flow region where Re is less than 2300.  Air, like the water in the picture, is also a fluid, and it will behave exactly in the same way depending on the Reynolds number.

Turbulent to Laminar Flows

Why is this important to know?  In certain applications, one state may be better suited than the other.  For mixing, particle suspension and heat transfer; turbulent flows are needed.  But, when it comes to effective blowing, lower pressure drops and lower noise levels; laminar flows are required.  In many compressed air applications, the laminar flow region is the best area to use compressed air.  EXAIR offers a large line of products, including the Super Air Knives and Super Air Nozzles that uses that laminar flow to generate a strong force efficiently and quietly.  If you would like to discuss further how laminar flows could benefit your process, an EXAIR Application Engineer will be happy to assist you.

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

Elevated Temperatures Can Really Affect A/C Panel Coolers

A food and beverage company contacted EXAIR, as they were having some issues with their air conditioning panel coolers. The units were located near ovens and the ambient temperatures were elevated.  During the summer months, the additional rise in temperature caused the air conditioning systems to under-perform.  The electronics were overheating and shutting down, causing production stoppage.  They needed a better way to keep the internal circuits cool during the hotter months.

The cooling capacities of the air conditioning panel coolers were over-sized to compensate for the high ambient conditions.  With the finicky nature of Freon systems, 8,000 BTU/hr units were required.  With the additional heat from summer, they had to continuously monitor and maintain the condenser units to keep them from running too hot.  This caused unneeded strain to their maintenance department, as it took time away from their normal duties.  They decided to contact EXAIR to see if our Cabinet Coolers could help in this situation.

Under normal conditions, refrigeration systems still have to be maintained by replacing filters, cleaning condensers, and checking compressors to prevent any failure.   Under elevated ambient conditions, it is very difficult to keep the Freon cool enough to operate adequately and the refrigeration compressor from over-heating.  EXAIR Cabinet Coolers do not use Freon or compressors to cool.  They use the power of a Vortex Tube which only needs compressed air to generate cold air.  With no moving parts to wear or unsafe chemicals to leak, they can keep the electrical components cool inside a panel for a very long time.

For sizing the EXAIR Cabinet Coolers, I needed some additional details.  I sent them the Cabinet Cooler Sizing Guide to help me determine the correct cooling capacity.  The information was as follows:

Height: 2200mm (87 inches)

Width: 800mm (31 inches)

Depth: 800mm (31 inches)

Internal heat load: 100 watts

Maximum Ambient: 70 deg. C (158 deg. F)

Required Internal Temp: 35 deg. C (95 deg. F)

NEMA Rating: NEMA 4X

Solenoid Voltage: 24Vdc

As an added note: they requested 316SS for anti-corrosion to be used for the Food and Beverage industry.

From my calculations, the ambient temperature was generating roughly 2,100 BTU/hr of heat on the external surface of the electrical cabinet.  The internal heat load was 100 watts or 341 BTU/hr.  Combining the values, the total heat load was 2,441 BTU/hr.  For the air conditioning units, they had to over-size the units to 8.000 BTU/hr of cooling capacity to remove 2,441 BTU/hr of heat.  This large difference is because of the high ambient conditions.  The EXAIR Cabinet Coolers do not have Freon to keep cool; so, the need to over-size is not necessary.  For the above electrical panels, I recommended a model HT4840SS-316-24VDC Cabinet Cooler System.  The cooling capacity is 2.800 BTU/hr, and it will keep the electrical components cool to 35 deg. C (95 deg. F) even during the hotter months of summer.

EXAIR NEMA Type 4/4X Cabinet Cooler System

With the EXAIR Cabinet Cooler Systems, we can offer a variety of different options to accommodate different applications.  For the food and beverage company above, the HT4840SS-316-24VDC was needed to meet the NEMA 4X rating of the panel and the 316SS construction for washdowns and corrosion resistance.  The “HT” at the beginning of the model number is for the High Temperature option.  This allows the Cabinet Cooler to operate in high ambient conditions between 52 deg. C to 93 deg. C (125 deg. F to 200 deg. F respectively).  The system comes with a filter, cold air distribution kit, a thermostat and a solenoid valve.  The thermostat is preset at 35 deg. C (95 deg. F) and operates the a 24Vdc solenoid valve to reduce compressed air consumption.  EXAIR stocks many different sizes and options to help reduce any downtime.  So, when an A/C system quits or an electrical panel faults out due to overheating, EXAIR can ship one out quickly to get the system up and running again.

If you have electrical panels over-heating or air conditioning units under-performing, you should try an EXAIR Cabinet Cooler.  You can fill out the Cabinet Cooler Sizing Guide and an Application Engineer can determine the best model to keep your operations running; even during the summer months.

 

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

 

Photo of Sun by Alexas_FotosCCO Creative Commons

Measuring and Adding Sounds

Sound

My colleague, Russ Bowman, wrote a blog about “Sound Power Level and Sound Pressure”.  He discussed the logarithmic equations around sound.  I will be discussing what happens when you have more than one sound source, as often heard within manufacturing plants.  Sounds can be added together to determine the overall sound level that your hear.  This is very important when it comes to minimizing hearing loss.

In looking at a single source of sound, sound pressure is created by the loudness of a noise.  The units are measured in Pascals.  The lowest pressure perceived by human hearing is 0.00002 Pa, and we can use this value as a reference point.  From sound pressures, we can arrive to a sound pressure level which is measured in decibel, dB.  This correlation between sound pressures and sound pressure levels are calculated by Equation 1:

 

 

L – Sound Pressure Level, dB

P – Sound pressure, Pa

Pref – reference sound pressure, 0.00002 Pa

As an example, the sound pressure from a passenger car as heard from the roadside is 0.1 Pa.  With Equation 1, we can get the following decibel level:

L = 20 * Log10 (0.1Pa/0.00002Pa) = 74 dB

Because human ears are sensitive to different frequencies, the sound pressure levels can be modified, or weighted, to indicate an effective loudness level for humans.  This adjustment is done in two different ways; A-weighting and C-weighting.  The C-weighting is for very loud noises with high peaks or sharp impacts like gunfire. The A-weighting is the most commonly used value as the sound pressure levels are adjusted by the frequency level.  For higher and lower frequencies, the change in the sound value is much greater than the mid-level frequencies that are within our hearing range.  Sound measurements for safety are measured in the A-weighted scale.  OSHA created a chart in the 29CFR-1910.95(a) standard that shows the noise levels over exposure times for an operator.  To use the OSHA chart accurately, the total noise level in dBA should be calculated.

OSHA Chart

To determine the total sound level, we can add all the sound pressure levels together by Equation 2:

 

 

Where L1, L2… represents the sound pressure level in dBA for each sound source.

As an example, a manufacturing plant had an operator using a machine that had four copper tubes to blow off a cutting operation (reference photo below).

Blow off station

The decibel level for a copper tube was measured at 98 dBA.  The total amount of sound that the operator was exposed to was determined by Equation 2 with four values.

L = 10 * log10 (109.8 + 109.8 + 109.8 + 109.8)

L = 104 dBA

In looking at the OSHA chart, the operator would only be allowed to operate the machine only a little over one hour without hearing protection.  In this same example, we replaced the copper tubes with an EXAIR Super Air Nozzle, model 1110SS.  The noise level for each nozzle is 74 dBA.  By replacing all four copper tubes with Super Air Nozzles, Equation 2 becomes:

L = 10 * log10 (107.4 + 107.4+ 107.4 + 107.4)

L = 80 dBA

The total sound level is now in accordance with OSHA regulations for the operator to work all 8 hours at the machine without hearing protection.

A commonly used acronym in hearing safety is NIHL, or Noise Induced Hearing Loss.  To keep your operators safe and reduce NIHL, it is important to measure the total sound level.  As a protocol in safety, it is a requirement to use engineering standards before purchasing personal protective equipment or PPE.  For the customer above, they followed that protocol with our Super Air Nozzles.  If you need to reduce noise levels in your facility by engineering standards, EXAIR offers a large line of blow-off products that can meet the safety requirements.

 

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

 

Photo of Ear auricle Listen by geraitCC0 Create Commons.

 

Compressed Air Regulators: The Design and Function

Regulator

Compressed air regulators are a pressure reducing valve that are used to maintain a proper downstream pressure for pneumatic systems.  There are a variety of styles but the concept is very similar; “maintain a downstream pressure regardless of the variations in flow”.  Regulators are very important in protecting downstream pneumatic systems as well as a useful tool in saving compressed air in blow-off applications.

The basic design of a regulator includes a diaphragm, a stem, a poppet valve, an orifice, compression springs and an adjusting screw.  I will break down the function of each item as follows:

  1. Diaphragm – it separates the internal air pressure from the ambient pressure. They are typically made of a rubber material so that it can stretch and deflect.  They come in two different styles, relieving and non-relieving.  Relieving style has a small hole in the diaphragm to allow the downstream pressure to escape to atmosphere when you need to decrease the output pressure.  The non-relieving style does not allow this, and they are mainly used for gases that are expensive or dangerous.
  2. Stem – It connects the poppet valve to the diaphragm. This is the “linkage” to move the poppet valve to allow compressed air to pass.  As the diaphragm flexes up and down, the stem will close and open the poppet valve.
  3. Poppet valve – it is used to block the orifice inside the regulator. It has a sealing surface to stop the flowing of compressed air during zero-flow conditions.  The poppet valve is assisted by a spring to help “squeeze” the seal against the orifice face.
  4. Orifice – it is an opening that determines the maximum amount of air flow that can be supplied by the regulator. The bigger the orifice, the more air that can pass and be supplied to downstream equipment.
  5. Compression springs – they create the forces to balance between zero pressure to maximum downstream pressure. One spring is below the poppet valve to keep it closed and sealed. The other spring sits on top of the diaphragm and is called the adjusting spring.  This spring is much larger than the poppet valve spring, and it is the main component to determine the downstream pressure ranges.  The higher the spring force, the higher the downstream pressure.
  6. Adjusting screw – it is the mechanism that “squeezes” the adjusting spring. To increase downstream pressure, the adjusting screw decreases the overall length of the adjusting spring.  The compression force increases, allowing for the poppet valve to stay open for a higher pressure.  It works in the opposite direction to decrease the downstream pressure.

With the above items working together, the regulator is designed to keep the downstream pressure at a constant rate.  This constant rate is maintained during zero flow to max flow demands.  But, it does have some inefficiencies.  One of those issues is called “droop”.  Droop is the amount of loss in downstream pressure when air starts flowing through a regulator.  At steady state (the downstream system is not requiring any air flow), the regulator will produce the adjusted pressure (If you have a gage on the regulator, it will show you the downstream pressure).  Once the regulator starts flowing, the downstream pressure will fall.  The amount that it falls is dependent on the size of the orifice inside the regulator and the stem diameter.  Charts are created to show the amount of droop at different set pressures and flow ranges (reference chart below).  This is very important in sizing the correct regulator.  If the regulator is too small, it will affect the performance of the pneumatic system.

The basic ideology on how a regulator works can be explained by the forces created by the springs and the downstream air pressures.  The downstream air pressure is acting against the surface area of the diaphragm creating a force.  (Force is pressure times area).  The adjusting spring force is working against the diaphragm and the spring force under the poppet valve.  A simple balanced force equation can be written as:

Fa  ≡ Fp + (P2 * SA)

Fa – Adjusting Spring Force

Fp – Poppet Valve Spring Force

P2 – Downstream pressure

SA – Surface Area of diaphragm

If we look at the forces as a vector, the left side of the Equation 1 will indicate a positive force vector.  This indicates that the poppet valve is open and compressed air is allowed to pass through the regulator.  The right side of Equation 1 will show a negative vector.  With a negative force vector, the poppet valve is closed, and the compressed air is unable to pass through the regulator (zero flow).

Let’s start at an initial condition where the force of the adjusting spring is at zero (the adjusting screw is not compressing the spring), the downstream pressure will be zero.  Then the equation above will show a value of only Fp.  This is a negative force vector and the poppet valve is closed. To increase the downstream pressure, the adjusting screw is turned to compress the adjusting spring.  The additional spring force pushes down on the diaphragm.  The diaphragm will deflect to push the stem and open the poppet valve.  This will allow the compressed air to flow through the regulator.  The equation will show a positive force vector: Fa > Fp + (P2 * SA).  As the pressure downstream builds, the force under the diaphragm will build, counteracting the force of the adjusting spring.  The diaphragm will start to close the poppet valve.  When a pneumatic system calls for compressed air, the downstream pressure will begin to drop.  The adjusting spring force will become dominant, and it will push the diaphragm again into a positive force vector.  The poppet valve will open, allowing the air to flow to the pneumatic device.  If we want to decrease the downstream air pressure, the adjusting screw is turned to reduce the adjusting spring force.  This now becomes a negative force vector; Fa < Fp + (P2 * SA).  The diaphragm will deflect in the opposite direction.  This is important for relieving style diaphragms.  This deflection will open a small hole in the diaphragm to allow the downstream air pressure to escape until it reaches an equal force vector, Fa = Fp + (P2 * SA).  As the pneumatic system operates, the components of the regulator work together to open and close the poppet valve to supply pressurized air downstream.

Compressed air is expensive to make; and for a system that is unregulated, the inefficiencies are much greater, wasting money in your company.  For blow-off applications, you can over-use the amount of compressed air required to “do the job”.  EXAIR offers a line of regulators to control the amount of compressed air to our products.  EXAIR is a leader in manufacturing very efficient products for compressed air use, but in conjunction with a regulator, you will be able to save even more money.  Also, to make it easy for you to purchase, EXAIR offer kits with our products which will include a regulator.  The regulators are already properly sized to provide the correct amount of compressed air with very little droop.   If you need help in finding the correct kit for your blow-off application, an Application Engineer at EXAIR will be able to help you.

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

Designing a Compressed Air Distribution System

Compressed air is used to operate pneumatic systems in a facility, and it can be segregated into three sections; the supply side, the demand side, and the distribution system.  The supply side is the air compressor, after-cooler, dryer, and receiver tank that produce and treat the compressed air.  They are generally located in a compressor room somewhere in the corner of the plant.  The demand side are the collection of end-use devices that will use the compressed air to do “work”.  These pneumatic components are generally scattered throughout the facility.  To connect the supply side to the demand side, a compressed air distribution system is required.  Distribution systems are pipes which carry the compressed air from the compressor to the pneumatic devices.  For a sound compressed air system, the three sections have to work together to make an effective and efficient system.

An analogy, I like to compare to the compressed air system, is an electrical system.  The air compressor will be considered the voltage source, and the pneumatic devices will be marked as light bulbs.  To connect the light bulbs to the voltage source, electrical wires are needed.  The distribution system will represent the electrical wires.  If the wire gauge is too small to supply the light bulbs, the wire will heat up and the voltage will drop.  This heat is given off as wasted energy, and the light bulbs will dim.

The same thing happens within a compressed air system.  If the piping size is too small, a pressure drop will occur.  This is also wasted energy.   In both types of systems, wasted energy is wasted money.  One of the largest systematic problems with compressed air systems is pressure drop.  If too large of a pressure loss occurs, the pneumatic equipment will not have enough power to operate effectively.  As shown in the illustration below, you can see how the pressure decreases from the supply side to the demand side.  With a properly designed distribution system, energy can be saved, and in reference to my analogy, it will keep the lights on.

Source: Compressed Air Challenge Organization

To optimize the compressed air system, we need to reduce the amount of wasted energy; pressure drop.   Pressure drop is based on restrictions, obstructions, and piping surface.  If we evaluate each one, a properly designed distribution system can limit the unnecessary problems that can rob the “power” from your pneumatic equipment.

  1. Restriction: This is the most common type of pressure drop. The air flow is forced into small areas, causing high velocities.  The high velocity creates turbulent flow which increases the losses in air pressure.  Flow within the pipe is directly related to the velocity times the square of the diameter.  So, if you cut the I.D. of the pipe by one-half, the flow rating will be reduced to 25% of the original rating; or the velocity will increase by four times.  Restriction can come in different forms like small diameter pipes or tubing; restrictive fittings like quick disconnects and needle valves, and undersized filters and regulators.
  2. Obstruction: This is generally caused by the type of fittings that are used.  To help reduce additional pressure drops use sweeping elbows and 45-degree fittings instead of 90 deg. elbows.  Another option is to use full flow ball valves and butterfly valves instead of seated valves and needle valves.  If a blocking valve or cap is used for future expansion, try and extend the pipe an additional 10 times the diameter of the pipe to help remove any turbulence caused from air flow disruptions.  Removing sharp turns and abrupt stops will keep the velocity in a more laminar state.
  3. Roughness: With long runs of pipe, the piping surface can affect the compressed air stream. As an example, carbon steel piping has a relative rough texture.  But, over time, the surface will start to rust creating even a rougher surface.  This roughness will restrain the flow, creating the pressure to drop.  Aluminum and stainless steel tubing have much smoother surfaces and are not as susceptible to pressure drops caused by roughness or corrosion.

As a rule, air velocities will determine the correct pipe size.  It is beneficial to oversize the pipe to accommodate for any expansions in the future.  For header pipes, the velocities should not be more than 20 feet/min (6 meter/min).  For the distribution lines, the velocities should not exceed 30 feet/min (9 meter/min).  In following these simple rules, the distribution system can effectively supply the necessary compressed air from the supply side to the demand side.

To have a properly designed distribution system, the pressure drop should be less than 10% from the reservoir tank to the point-of-use.  By following the tips above, you can reach that goal and have the supply side, demand side, and distribution system working at peak efficiency.  If you would like to reduce waste even more, EXAIR offers a variety of efficient, safe, and effective compressed air products to fit within the demand side.  This would be the pneumatic equivalent of changing those light bulbs at the point-of-use into LEDs.

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

 

Photo: Light Bulb by qimonoCreative Commons CC0