Please ensure Javascript is enabled for purposes of website accessibility

Don't Make This Mistake

Many businesses using bottled nitrogen could actually produce their own nitrogen at a fraction of the cost that they buy it.

There are three underlying reasons for this:

  1. A vendor supplying you with bottled nitrogen uses cryogenic distillation which is very energy intensive and passes this cost on to its customers
  2. There are a lot of cases where nitrogen with a higher purity than needed is purchased.
  3. Transport costs associated with moving the gas

Cryogenic distilled nitrogen produced through this process can attain a purity of 99.99% or higher – which is needed for certain applications. 99.99% and higher purity is only necessary in a handful of electronic assembly functions – Pharmaceuticals and food and beverage applications don’t even need 99.99% purity as a rule of thumb.

In many cases nitrogen in cylinders from a commercial gas company is the most expensive option. Costs are slightly lower for liquid nitrogen in a Dewar or bulk tank.

What Purity Of Nitrogen Can I Generate On-Site?

On-site nitrogen generators can be used to create on-demand gaseous nitrogen at purity's up to 99.999%.

What’s important to note is that you can inexpensively produce 95% to 98% pure nitrogen (5%-2% oxygen) which is suitable for a majority of applications – rather than over-paying for higher purity nitrogen from a commercial supplier. The choice of generator largely depends on the purity of nitrogen needed. Whatever purity you need, the level of O2 can be adjusted to your required purity level.

As a rule applications that need nitrogen of 95 to 98% purity, I’d recommend using membrane generators which produce nitrogen at the lowest cost per cubic foot.

Applications such as the blanketing of oxygen sensitive compounds, specialty chemicals and pharmaceutical processing need a high purity stream that requires the use of Pressure Swing Absorption (PSA) generators.

What Are The Costs To Generate On-Site Nitrogen?

On-site PSA and membrane systems are energy efficient and cost effective, requiring only enough energy to power the air compressor that supplies air to the system. Gas industry sources indicate that an air separation plant uses 1976 kJ of electricity per kilogram of nitrogen at 99.9% purity.

At a purity of 98 percent, the energy required for in-house nitrogen consumes 62 percent less energy.

Even for those applications requiring 99.9% purity, generating nitrogen in-house on-demand with a PSA system will use 28 percent less electrically compared to power costs for a third-party produced bulk nitrogen.

If you are looking to end your reliance on third party Nitrogen suppliers, we can help you with a nitrogen generation system that produces the purity you need in the quantities you need for a fraction of the cost of buying Nitrogen in. Call the team at Pye-Barker 404-363-6000 or drop us a line sales@pyebarker.com and we can help you design your nitrogen system, supply it and install it.

When you’ve grown up around air compressors – literally in my case, it means that the jargon is second nature. However I know I often forget this when speaking to clients and often there is confusion when a couple of different terms get blurred.

So I thought I’d take the time to remind you of those easy to confuse definitions.

Compressor Capacity Definitions

Capacity is the quantity of air the compressor can pump out. Capacity is rated at based on the conditions of pressure, temperature and moisture content existing at the compressor inlet flange.

Mass flow (lb/min or kg/hr) Compressor performance is specified by a curve of delivery pressure against a mass flow rate for a constant velocity:

CFM (Cubic Feet per Minute) (M3/min) is a volumetric measurement not dependent on inlet conditions such as temperature, pressure and humidity.

ACFM (Actual Cubic Feet per Minute) (M3/min) represents ‘useful air’ and is independent of the seal losses through the machine. The commonly used value for seal losses with carbon seals is about 1%. Some centrifugal compressors may have other air losses between the inlet and discharge flanges.

ICFM (Inlet Cubic Feet per Minute) (or M3/hr) is a measure of the air entering the compressor. ICFM is the most common method of determining centrifugal compressor selection.

FAD (Free Air Delivered) indicates delivered air at inlet conditions. FAD is read before the inlet filter and inlet piping thus not taking into account this pressure drop which is normally anywhere from .2 to .5 PSIA with a relatively clean filter. This can be misleading because performance is calculated on an inlet pressure that is higher than the actual air volume entering the unit resulting in lower output than expected.

ICFM, ACFM and FAD are used interchangeably to reference delivered air. When using published data to run operating performance comparisons it is important to use ICFM or ACFM or FAD consistently. Be clear if inlet pressure is being acquired or estimated.

What is SCFM? SCFM (Standard Cubic Feet per Minute) (Nm3/hr) is the CFM at normal inlet conditions of 14.5 PSIA(1 bar), 68° F (20°C), and 0% relative humidity. SCFM can be based on inlet or discharge and it should be specified one way or the other. The most common use is inlet flange measurement.

Operating comparisons should only be evaluated at the same inlet temperature, pressure, relative humidity and cooling water conditions, as well as the same discharge pressure.

A good supplier will want you to specify worst case conditions, i.e. warmest conditions to insure the compressor is capable of meeting the desired output. If you don’t you’ll get the standard design conditions of:

Compressor Pressure Definitions

PSI is a pressure rating which means pounds per square inch.

PSIG is gauge pressure which reads the psi above the ambient or barometric pressure:

PSIA is ambient barometric pressure that varies with the altitude and the weather. This is a very important value when evaluating or estimating any compressor performance; particularly, centrifugal compressors. PSIA is needed to convert ICFM or ACFM to SCFM (M3/hr to Nm3/hr).

Understanding Horsepower and power cost

Motor horsepower – references the nameplate horsepower.

(BHP) Brake Horsepower is the input power required at the compressor input shaft to drive compressor at rated flow and rated pressure.

Input Motor Power in kW – (can be measured or calculated) that generates kWh – the amount of power consumed which drives the power bill. Input motor power is affected by such factors as motor efficiency, power factor, motor conditions, starter and disconnect conditions, power quality and many more.

Specific Power

SCFM (Nm3/hr) is typically the flow rating (projected or measured) for an input kW. With this data, each unit’s specific power in SCFM or Nm3/hr/kW input is calculated. (Note that many manufacturers use BHP/100 cfm.)

BHP/100 cfm does not include the actual operating energy requirement (such as other losses in the couplings, main drive, and controls which increase the projected operating up to 20%).

I hope this guide has explained some of the subtle differences between different air compressor performance measures. If you need help assessing your needs for a new air SCFM air compressor or having trouble with the performance of an existing unit then give the team at Pye-Barker a call on 404-363-6000 or drop us a line sales@pyebarker.com and we will take care of you.

Why Do Compressed Air Systems Need Drying

Manufacturing and processing has seen a boom in compressed air usage over the last decade or so. Devices and controls have become more sophisticated and in turn less tolerant of damp compressed air.

Traditionally, moisture in compressed air was simply tolerated. Despite the fact it can cause trouble in pneumatic systems, solenoid valves and air powered motor

Moisture can also:

How Does Wet Air Affect Different Components of My Compressed Air Systems

The Plant Wide Air System – Dirt, water and oil in your compressed air lines and the inner surfaces of pipes and fittings, can cause an increase in pressure drop resulting in reduced efficiency and higher costs.

Water condenses out of the air and builds up in the system accelerating corrosion and shortening the useful life of equipment. Corrosion particles can accumulate in plug valves, fittings and instrument control lines.

Valves and Cylinders – experience a build-up of sludge which consists of dirt, water and oil in the compressed air. The sludge acts as a drag on pneumatic cylinders so that the seals and bearings need more frequent maintenance intervals. Moisture dilutes the oil required for the head and rod of an air cylinder and can corrode the walls and slows response. Moisture flowing to rubber diaphragms in valves can cause these parts, to stiffen and rupture.

Air Powered Tools – Dirty and wet air will result in sluggish operation, more frequent repair and replacement of parts due to sticking, jamming and rusting of wearing parts. Water also will wash out the required oils, resulting in excessive wear. A decrease in pressure at the tool caused by restricted or plugged lines or parts reduces each tool’s efficiency and effectiveness.

These tools are designed to run on high grade compressed air – make sure your air matches the tool manufacturer’s specifications.

Instrument Air – A small amount of moisture passing through an orifice can cause malfunction of the instrument and the process it controls. Corrosion particles in the air system also can cause damage to instruments and plug their supply airlines.

Instruments and pneumatic controllers in power plants, sewage treatment plants, chemical and petrochemical plants, textile mills and general manufacturing plants, all need clean, dry air for efficient operation.

Preservation of Products – When used to mix, stir, move or clean a product, air must be clean and dry. Otherwise you risk damaging or contaminating the product. Moisture in control line air can cause the wrong mixture of ingredients in a bakery, the incorrect blend in liquor, waterlogged paint, or ruined food products.

As you can see moisture contamination in your compressed air can lead to all sorts of problems for your compressed air system. Getting the right dryer(s) installed can go a LONG way towards minimizing your down time and maximizing the length and quality of life of your compressed air processed and equipment.

If you are experiencing too much down time, intolerably high maintenance bills or just think you might be paying too much for your compressed air then give the team at Pye-Barker a call on 404-363-6000 or drop us a line sales@pyebarker.com. We can guide you through cutting your compressed air costs in any number of ways.

Six More Mistakes You Could Be Making To Shorten The Life Of Your Pumps

Don't Shorten The Life Of Your Pumps

Last month I shared with you six mistakes that could be shortening the life of your pumps. In this follow up article I’ll share with you another six mistakes that could be shortening the life of your pumps.

Not Minimizing Radial Force

Industry statistics indicate that the biggest reason centrifugal pumps are pulled from service is the failure of bearings and/or mechanical seals. Bearings and seals wear and tear give you a good idea of what is happening inside the pumping system.

To minimize radial force run your pump at its Best Efficiency Point (BEP). At its BEP, by design pumps will experience the lowest amount of radial force. High radial force and shaft deflection are a killer of mechanical seals and a contributing factor to bearing life reduction.

Not Changing Your Oil On Schedule.

For ball bearings, more than 85 percent of bearing failures result from contamination, either dirt and foreign material or water. Just 250 parts per million (ppm) of water will reduce bearing life by a factor of four.

Operating a pump can be similar to operating a car continuously at 60 miles per hour… Driving 24 hours per day, seven days a week, puts plenty of ‘miles on the clock’ —1,440 miles per day, 10,080 miles per week, or if you will 524,160 miles per year. You’d be checking your car’s oil regularly if you were doing those sorts of miles wouldn’t you? Why not check your pump’s oil regularly too?

Not Reducing The Risk of Cavitation.

Cavitation will create damage to the pump impeller, and resultant vibrations will affect the seals and bearings. Cavitation is minimized by having a large margin between net positive suction head available (NPSHA) and the net positive suction head required (NPSHRR).

Running Your Pump At High Speeds

A 3600-rpm pump will wear out faster than a 1800-rpm pump by a factor of 4-to-8. So if you’ve got to run a pump at high RPMs, when it does finally wear out be sure to look for a pump that can move the same volume of material while running at a lower speed.

Unbalanced Impellers

I recommend that impellers be balanced to International Organization for Standardization (ISO) 1940 grade 6.3 standards at a minimum. If the impeller is trimmed for any reason, it must be re-balanced.

An unbalanced impeller on an overhung pump or on some vertical designs can cause a condition known as shaft whip, which deflects the shaft just as a radial force does when the pump operates away from the BEP. Radial deflection and whip can occur at the same time.

Too Many Casing Penetrations

Many end users want the casing drilled and tapped for drains, vents, gauge ports or instrumentation. The problem is pump casing penetrations shorten pump life. Every penetration is primed for corrosion and stress risers. It’s a trade-off.

If you find yourself frustrated with pumps being continuously offline for unscheduled maintenance or need to increase the life of your pumps give the team at Pye-Barker a call at 404-363-6000 or drop us a line at sales@pyebarker.com we will advise you on your best options to increase your pump life.

AUTHORIZED DISTRIBUTORS FOR

pye authorized logos
banner image
banner image
Forest Park (Atlanta) Address:
121 Royal Dr.
Forest Park, GA 30297
FAX: (404) 361-8579
Sylvania Address:
452 Industrial Park Rd.
Sylvania, GA 30467
FAX: (912) 564-2636
Orlando, FL Address:
524 Mid-Florida Dr., Suite 204
Orlando, FL 32824
FAX: (321) 282-6424
Copyright © 2019. Pye-Barker Supply Company. All Rights Reserved.
Marketing by:
 S3 Media
Translate »
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram