Air Compressor Motors and Controls, Working Together.

One of the most important aspect of an efficient compressed air delivery system is effective utilization of compressor controls. The proper use of compressor controls is critical to any efficient compressor system operation. In order to reduce operating costs, compressor controls strategies need to be developed starting with minimizing the discharge pressure. This should be set as low as possible to keep energy costs to a minimum.

The compressor system is designed with maximum air demand in mind. During periods of lower demand compressor controls are used to coordinate a reduction in output that matches the demand. There are six primary types of individual compressor controls:

  1. Start/Stop – This is the most basic control. The start/stop function will turn off the motor in response to a pressure signal.
  2. Load/Unload – The motor will run continuously, but the compressor unloads when a set pressure is reached. The compressor will then reload at a specified minimum pressure setting.
  3. Modulating – Restricts the air coming into the compressor to reduce compressor output to a specified minimum. This is also known as throttling or capacity control.
  4. Dual/Auto Dual – On small reciprocating compressors, this control allows the selection of either Start/Stop or Load/Unload.
  5. Variable Displacement – Gradually reduces the compressor displacement without reducing inlet pressure.
  6. Variable Speed – Controls the compressor capacity by adjusting the speed of the electric motor.

All of these controls then control the compressor motors and they have several different starting methods.

There are several types of modern motor starters:

Full Voltage Starters: The original, and simplest method.  These are similar in theory to the old knife switches, but the operator’s hands aren’t right on the connecting switch.  Full line voltage comes in, and amperage can peak at up to 8 times full load (normal operating) amperage during startup.  This can result in voltage dips…not only in the facility itself, but in the neighborhood.  Remember how the lights always dim in those movies when they throw the switch on the electric chair?  It’s kind of like that.

Reduced Voltage Starters: These are electro-mechanical starters.  Full line voltage is reduced, commonly to 50% initially, and steps up, usually in three increments, back to full.  This keeps the current from jumping so drastically during startup, and reduces the stress on mechanical components…like the motor shaft, bearings, and coupling to the compressor.

Solid State (or “Soft”) Starters: Like the Reduced Voltage types, these reduce the full line voltage coming in as well, but instead of increasing incrementally, they gradually and evenly increase the power to bring the motor to full speed over a set period of time.  They also are beneficial because of the reduced stress on mechanical components.

The Application Engineering team at EXAIR Corporation prides ourselves on our expertise of not only point-of-use compressed air application & products, but a good deal of overall system knowledge as well.  If you have questions about your compressed air system, give us a call.

Jordan Shouse
Application Engineer

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Compressor Photo Credits to Bryan Lee, Creative Commons License

EXAIR has a Line Vac for your Application!

With countless number of different Models to fit every application, EXAIR Line Vacs are used to convey everything from the lightest of packing peanuts to heavy steel shot.  They’re versatile, reliable, durable, and incredibly easy to install and operate. 

Line Vacs are EXAIR’s current promotion too, see the offer here.

EXAIR Line Vacs use a small amount of compressed air to generate a powerful vacuum by a Venturi effect.  The unique design of the generator creates a high velocity of air to create a low pressure on one side and a powerful thrust on the other. The Line Vac can pick up and move solid material from light and fluffy batting to dense, heavy and abrasive material and pieces.  They can transfer product horizontally up to 100 feet (30 meters) away and vertically up to 20 feet (6 meters) high.  You can watch a video on the operation of a Line Vac HERE.  Compared to other vacuum or conveying systems, the EXAIR Line Vacs are very quiet, rugged, and powerful. They are exceptionally simple to install and solve many “bucket and ladder”, loading and scrap removal applications. EXAIR makes a variety of Line Vacs in different sizes, styles, and materials to best fit your application.

The standard Line Vac is the most versatile product in this family.  EXAIR stocks a wide range of sizes, materials, and styles for targeting the best solution for moving material.  We have two types of connections, slip-on ends for hose connections and threaded ends for pipe connection.  EXAIR can swap the connections with a slip-on hose on one end with a threaded connection on the other.  They range in diameters from 3/8” (10mm) up to 5” (127mm).  We manufacture the Line Vacs in aluminum, 303SS, and 316SS; but don’t let that deter you if your need them manufactured in any other type of material.  We have high temperature models that can withstand temperatures up to 900 deg. F (482 deg. C).  These Line Vacs work great in applications for loading plastic pellets in hoppers, discarding scrap pieces, trim removal, and transferring material.  If an operator has to carry a container of dry material and climb stairs, a Line Vac could be a much better alternative.

Heavy Duty Line Vac: Hardened Alloy Construction and High Performance

The Heavy Duty Line Vacs are made from a hardened alloy steel for abrasion resistance.  The generators inside these Line Vacs are more powerful than the standard models; so, that they can also convey heavier materials at higher conveyance rates.  They can reach rates as high as 40 lbs./min. (18.2Kg/min) of material.  With the hardened alloy construction, they are great for sand blasting applications, ceramic, glass and steel shot.  They are manufactured with inlet and outlet connections for ship-on hoses or threaded pipes.  EXAIR stocks the Heavy Duty Line Vacs in the range from ¾” (19mm) to 3” (76mm) for both hose and NPT connections.  These Line Vacs are our most powerful design with great wear resistance.

EXAIR’s Light Duty Line Vac

On the other end of the Line-Vac spectrum, EXAIR also manufactures the Light Duty Line Vac.   They use much less compressed air than the other Line Vacs which work great for moving lightweight materials over short distances.  They can also be used for removing smoke and fumes from a work area.  The Light Duty Line Vac ranges from ¾” (19mm) up to 6” (152mm) diameter for slip-on hose connections.  This two-piece design provides an effective way of moving material at a lower cost.  It can be used in applications like hopper loading, fiber tensioning, filling operations, and smoke removal.   For moving material within a short distance, the Light Duty Line Vac could be the proper product to use.

Model 161200-316 – 316 Stainless Steel Sanitary Flange Line Vac

Our latest engineering design within the Line Vac family is the Sanitary Flange Line Vacs.  They can fit within sanitary piping systems to convert pipes into a useful conveyor for bulk material and waste removal.  They use an ISO2852 flange for easy disassembly and cleaning to reduce bacterial entrapment.  They ae made from 316 stainless steel material for superior corrosion resistance.  They come in four different sizes to fit the sanitary flanges from 1-½” up to a 3” flange.  For sensitive applications where cleanliness is a major requirement, the Sanitary Flange Line Vac are manufactured for these conditions.

We are also able to make custom Line Vacs to mean any application, see an example of some unique to the application Line Vacs here, https://blog.exair.com/2020/07/01/custom-products-for-custom-applications/

With all of the EXAIR Line Vacs above, they can be sold as kits.  A kit will include a filter, regulator and a bracket.  (A bracket is not sold with the Light Duty Line Vac kits.)  The filter will help keep the Line Vac clean as well as the product that it is conveying.  The regulator is a great tool to vary the conveyance rates for better control.  The bracket helps to mount the Line Vac to a sturdy base for support.  A useful accessory to conveniently hide the compact Line Vac for ease of use and operation.

If you have any questions on how our Line Vacs can help save you money give us a call! One of our application engineers will be happy to assist!

Jordan Shouse
Application Engineer

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Let Solenoid Valves and Ball Valves save you Money!

Step 4 of the Six Steps to Optimizing your compressed air is to turn off your compressed air when it is not in use. This step can be done using two simple methods either by using manual controls such as ball valves or automated controllers such as solenoid valves. Manual controls are designed for long use and when switching on and off are infrequent. Ball Valves are one of the most commonly used manual shut offs for compressed air and other fluids.

  • Manual Valves allow for operators to turn on and off their system by hand. The full-flow ball valves range from ¼” NPT to 1 1/4” NPT in size and will not restrict flow.  EXAIR also offers a manual foot pedal valve for hands-free operations.  This ¼” NPT foot valve has a 3-way operation and works great if the operator has to use both hands in their process.
  • Solenoid Valves are a way to turn on and off the supply of compressed air electrically for automated systems. We offer solenoids in three different voltages; 110Vac, 240Vac, and 24Vdc.  EXAIR has a large range of flows with ports ranging from ¼” NPT to 1” NPT.  All models are UL listed and are CE and RoHS compliant.
Top Left: Solenoid Valve , Bottom: Manual Foot Valve , Right: Manual ball valve

By turning off your compressed air, whether it be with manual or automated controllers, a company can minimize wasted compressed air and extend the longevity of the air compressor that is used to supply the plants air. The longevity of the air compressor is increased due to reduced run time since it does not need to keep up with the constant use of compressed air. Other benefits include less use of compressed air and recouped cost of compressed air. 

EXAIR’s Ball Valves sizes 1/4″ NPT to 1-1/4″ NPT

If you have any questions on how these easy to install accessories can help save you money give us a call! One of our application engineers will be happy to assist!

Jordan Shouse
Application Engineer

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Turn the Pressure Down, Save Operation Costs

I recently recommended to a customer to turn their air pressure down on their system as low as their process would allow. Meaning regulate the pressure so you have enough to complete the operations needed but find that happy medium where your compressor isn’t working as hard to build those high pressures for no reason!

Compressed air is an amazing tool to have, and when used properly it can be more efficient that other non compressed air tools that run off electricity. How ever its pretty common to see compressed air systems running at their max just because.

Lowering the air system pressure reduces the compressor power consumption by about 1% for every two psi of lower pressure. Lowering the pressure also makes any unregulated operations reduce consumption by almost 1% for every one psi of pressure reduction. Not to mention the extra savings if your compressor system can turn down the compressor power because of the reduced flow and possibly shut off compressors that are no longer needed!

The best pressure at which to set your system is the level where your production can operate efficiently and effectively without waste: There is no right pressure—it depends on your operations and tools. You may have 90 to 100 psig at the compressor, but at the production machine, where the actual work is being done, you could have only 65 to 70 psig. In some cases, it may be even lower due to pressure drops in undersized piping, filters, regulators. The goal is to lower compressor discharge pressure without affecting the the operations at the end of the line.

Having artificially high plant-pressure can help you deal with surges in compressed air demand that might occasionally cause low-pressure and affect production. The higher pressure acts to store reserve air in the various volumes made up of receivers, pipes and such in your system. However, the higher pressure costs more to produce and makes unregulated end uses consume more air, which is an expensive trade-off. Another option is to make sure you have line pressure regulators at each point of use. This will allow you to regulate the operation to the pressure needed being sure to save compressed air and keep the over all system running more efficient.

You can regulate those point of use lines with a number of EXAIRs Pressure Regulators!

EXAIR offers a range of Pressure Regulators capable of handling air flow of up to 700 SCFM.

If we can help size a regulator, or have any other questions on how EXAIR can help you save compressed air in your system please reach out to me or one of our other Application Engineers!

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS