Natural Gas Cost Vs Electricity

January 12, 2016January 12, 2016Ken Bean

I recently received a phone call from a client asking for some preliminary pricing on a centrifugal compressor that was driven with a natural gas engine. I’ll have to admit, in my years in the compressed air field I had never had this request but I’m always willing to seek out new idea’s.

Contacting my regional engineer for some guidance, I found this is more common than I knew and the factory could accommodate the request for budget pricing.

My clients goal with this project is to meet a corporate mandate that electrical consumption be reduced by 25% over the next several years. His thought was the cost of natural gas could potentially be lower than their cost for electricity or at least near the same. By utilizing natural gas the reduction in electrical consumption could be met. I know over the past few years that many of my power generation clients are moving to mothball coal fired gas plants and they are being replace by natural gas fired plants. Although their direction is being pushed much harder by EPA emission mandates than by fuel cost.

Further researching this type of driver, I found it is much more common in the oil & gas industry than in other area’s of manufacturing. While researching the idea I also found an article written by our friends over at Bechtel Engineering and thought there might be some interest from our readers to look into this further as well.

You can read the overview and download the whitepaper at the following link: http://bit.ly/1RwSjy4

I’ll keep you posted on my clients project and let you know how this progresses and also the determination of how this change would actually pay off in the end from both a reduction of carbon footprint along with overall fuel cost.

The Power Company Loves You

January 5, 2016Ken Bean

With a powerhouse full of compressors, your power company wakes up looking like the little boy pictured below; just thinking of the money it will make from you today.

How much does it cost to run those air compressors?

Compressed air is one of the most expensive uses of energy in a manufacturing plant. About eight horsepower of electricity is used to generate one horsepower of compressed air. Calculating the cost of compressed air can help you justify improvements for energy efficiency.

Cost per year To find the annual cost of electricity used to power a compressed air system, calculate the cost for running the system under loaded and unloaded conditions. For each, multiply:

horsepower (hp)

conversion factor 0.746 kW/hp

total operating hours per year (hr/yr)

cost per kilowatt-hour ($/kWh)

% time fully-loaded or unloaded

% full-load hp, loaded or unloaded

Divide the product by the motor’s efficiency.

Use the formula below for your calculations.

Find A Leak To Fix A Leak

December 28, 2015December 28, 2015Ken Bean

Leak Detection

A small leak in your compressed air system may not seem like a big deal. Until you consider that small leak at 1/32” diameter will pass 1.62 SCFM on an air system running at 100 PSIG. That equates to 2,332 SCFM in a 24 hour period. This shows with just a few small leaks, they can quickly add up to the equivalent of several horsepower of compressed air being required just to satisfy the leaks.

The best way to detect leaks is to use an ultrasonic acoustic detector, which can recognize high frequency hissing sounds associated with air leaks. These portable units are very easy to use. Costs and sensitivities vary, so test before you buy. A simpler method is to apply soapy water with a paintbrush to suspect areas. Although reliable, this method can be time consuming, messy and on some applications, near impossible to reach.

Utilizing Compressed Air Storage

December 15, 2015December 21, 2015Ken Bean

If you look at most any industrial compressed air system you will find a receiver located somewhere in the layout. However, just having a receiver does not mean the system is fully utilizing the capability of the storage.

Properly utilized compressed air storage should allow a compressed air system to meet its peak demand needs and help control system pressure without starting additional compressors. The correct type and quantity of air storage depends on air demand patterns, air quantity and quality required, and the compressor and type of controls being used. An optimal air storage strategy will enable a compressed air system to provide enough air to satisfy temporary air demand events while minimizing compressor use and pressure.

To properly utilize the stored compressed air the pressure in the receiver needs to be stored at a higher pressure than the system pressure. The strategy is to allow the differential between these 2 pressures to be sustained by incorporating a pressure flow controller (PFC) and/or metering valves.

This allows the pressure in the demand side to be reduced to a stable level that minimizes actual compressed air consumption. PFCs are added after the primary receiver to maintain a reduced and relatively constant system pressure at points of use, while allowing the compressor controls to function in the most efficient control mode and discharge pressure range. Properly applied, a PFC can yield significant energy savings in a system with a variable demand load.

A professional air audit can determine the proper storage size requirements.

Turn It Off

December 8, 2015December 8, 2015Ken Bean

Those big air compressors in the back that nobody wants to look at consume a huge amount of energy. A 100 horsepower compressor can cost $75,000 per year in energy costs (based on 8,760 hours at $0.10 per kilowatt hour). Utilizing automation, storage and flow control, system balancing and best use practices along with other details, can allow you to turn some compressors off. Just running the above mentioned 100 HP compressor during lunch each day can cost up to $3,000.00 annually.

An Air Audit today could save thousands next year!

Saving Energy On Compressed Air Does More Than Save Money

December 1, 2015August 3, 2016Ken Bean

Approximately 70% of all manufacturers have a compressed air system. These systems power a variety of equipment, including machine tools, material handling and separation equipment, and spray painting equipment. Energy audits conducted by the U.S. Department of Energy (DOE) suggest that over 50% of compressed air systems at small to medium sized industrial facilities have low-cost energy conservation opportunities.

Significant air emissions are released when electricity is produced. A recent study for the state of Minnesota, indicated that one-fourth of the energy-related emissions of carbon dioxide, sulfur dioxide, lead and mercury are from generating electric power. Industry uses over 34% of this electricity. Reducing electricity used by compressed air systems will help improve everyone’s air quality.

A team of qualified auditing engineers is the correct way to evaluate your system.

Contact me today to schedule a consultation.

Compressed Air Alternatives

November 24, 2015November 24, 2015Ken Bean

Although compressed air is readily available and convenient to use in most plants, it is often more cost-effective to find an alternate solution to some problems. Some studies have shown that the overall efficiency of a typical compressed air system can be as low as 10% to 15%. With that in mind, using a fan or even modifying an air conditioning system to cool a component is likely to be less expensive in the long run than installing a compressed air vortex cooler.

Vacuum systems are more efficient and safer for cleaning than compressed air. Electric tools are less expensive to operate than their pneumatic counterparts, although torque and industrial durability need to be considered when selecting the right tool for the job. Ultimately, a person needs to consider all options and use compressed air only when it truly makes sense.

“The above statements are taken from the DOE Compressed Air Challenge website”

If you answer “yes” to any of the following, your use of compressed air can likely be reduced! We offer Free on site consultation to evaluate your compressed air needs.

Can this application use compressed air at a lower pressure?
Is the pressure required for this application in the range of a blower rather than a compressor?
Does the application use large volumes of air for short burst of time? ie. Chip blowing or bag house filter blow off
Is this application using compressed air for parts cooling or drying?

Is My Desiccant Bad?

November 17, 2015November 17, 2015Ken Bean

I recently suggested to a client that it was near time for a desiccant change. His response was, How do I know the desiccant needs changing and what impact or improvements new desiccant would make. He also wanted a factory statement on the life span of desiccant in his heatless dryer which in this case is activated alumina. Below is my response to him and I thought it might be beneficial for others as well.

The typical life span on desiccant in a heatless dryer is 3-5 years. Desiccant will typically last longer in a heatless since there is less thermal shock.

I’m not aware of anyone that publishes estimated life span.

The benefits of new desiccant are better dewpoint and lower pressure drop.

The desiccant in a dryer degrades because of attrition (the desiccant rubbing against itself which wears the bead size down), thermal degradation (if the desiccant is in a heated dryer) and of course if the dryer happens to be installed on a lubricated compressor system then it will go bad much quicker due to oil fouling. Once oil attaches to the desiccant bead, the pores of the bead are coating with oil (which cannot be removed) thus eliminating the desiccants ability to adsorb water vapor.

A good indicator of desiccant condition is to use a portable hygrometer on the downstream airline to see what actual dewpoint is being achieved.

Another indicator that desiccant is going bad is quicker than normal loading on the particulate filter downstream. As the desiccant deteriorates it creates more dust to be blown downstream which is then captured in the particulate filter.

Another check is the differential pressure across the dryer. Determine the clean differential pressure from the manufacturer and then compare that information to the actual Delta P between the dryer inlet and outlet. The higher the differential pressure above factory specifications indicates a worsening desiccant condition. Assure the factory number used for comparison either includes (or does not include the pre & post filters) and check the corresponding pressures for comparison.

The last suggestion is to obtain a desiccant test kit, pull a desiccant sample from the dryer and have it sent for analysis. However, to assure an accurate test the sample should be pulled from the middle of the desiccant bed which is often difficult and this service usually incurs a charge which is why I suggest it as the last option.

Proper Drains Create A More Efficient Compressed Air System

November 9, 2015November 10, 2015Ken Bean

Industry is beginning to understand the true cost of compressed air and it is not cheap. We work with a host of companies every day to reduce their compressed air cost and improve on the reliability of the compressed air system.

If your company only takes one step on it’s own to create a more efficient system for yourself then consider installing the correct condensate drain valves.

Using compressed air for an intended purpose is an obvious goal but we often find that the compressed air ends up being used in unnecessary and wasteful ways. Like blowing debris from parts or workers which is an obvious waste of a utility. Even more concerning is waste that occurs from improperly selected equipment and drain valves fall firmly on that line.

Everyone knows that compressed air systems create huge volumes of water that must be eliminated from the system at any location in the system where the air temperature drops, thus creating liquid water. These area’s typically include intercoolers, aftercoolers, refrigerated dryers and receivers . At these points, equipment (drain valves) must be installed to remove the liquid water from the system collection points.

A simple solution utilized in many systems is a timed based solenoid drain.

There are a couple of potential problems with a solenoid type drain valve. First, most of these drains utilize a very small orifice (port) where the water is discharged from the system making it susceptible to blockage by dirt, sludge or rust particles. Second, the drain discharges compressed air with the water which is a waste of the utility and Third, the timed function of the drain never takes the amount of water into consideration. Maybe the drain is open too long or perhaps the timed event is too short and the water is not completely discharged from the system.

A much better approach is to utilize a zero air loss type automatic drain like the Dehydra 52 shown below.

How It Works

Condensate enter the drain through one of he two inlet connections. A non-metallic float is tethered to a float arm. As condensate is collected and the translucent reservoir fills, the float rises. When the condensate reaches a designed level, the float lifts the trigger assembly and a drain cycle is initiated. The trigger assemble opens and directs control air to the valve actuator, which in turn opens the full-port drain valve.

The compressed air line from the water collection point is closed and condensate will then exit the unit. As the condensate level drops, the trigger assembly closes and the valve actuator closes the drain valve. The drain is returned to a standby condition.

Thus the collection point is fully drained and the during the draining process, no compressed air is lost from the system.

The drain valve is an area your company can easily make an impact to improve your compressed air system.

Cold Slows Production

November 3, 2015August 3, 2016Ken Bean

Throughput Suffers When Plant’s Freeze

Everyone knows frozen air lines bring a plant to a halt. The solution is to properly maintain your compressed air dryer. Call me before the cold weather brings you to a halt. My service technicians can repair or maintain any brand of dryer both regenerative and refrigerated.