Industrial Utility Efficiency    

Custom-Engineered Instrument Air Dryers for Refineries

Atlas Copco has a long history serving the Houston-based energy and chemical industries with custom-engineered packages. The objective of this article is to show just a few examples of the custom applications typically engineered and manufactured in the Atlas Copco Houston operation. Opened in 2012, Atlas Copco Houston produces standard compressed air dryers as well as completely engineered air dryers for all markets. The air flow capacity of the dryers, produced at this location, vary from 5 to 12,750 scfm. This capacity range covers heatless, heated purge and blower purge air dryers. Atlas Copco also builds air compressor skid packages with other air treatment products and receiver tanks at this location.

Compressed air is a very important and safe source of energy used in chemical refineries and in the oil and gas industry. Typically, these industries require regenerative desiccant air dryers to control the moisture level of the compressed air used with pneumatically controlled devices. This is commonly called “Instrument Air” and usually carries a  -40 0F (-40 0C) pressure dew point specification.  It is possible, however, to see dew point specifications down to – 100 0F (-73 0C).

 

Atlas Copco Energy Team

The Atlas Copco Houston Engineering and Proposal-Engineering Team

 

Gasification process in the Middle East: Six Instrument Air Dryer Trains for a Class 1 Div 2 Environment

One of the first engineered air dryers was for a major oil and gas company. This project included six (6) instrument air trains for a gasification process in the Middle East. The trains are grouped in three (3) stations where one train is operating and the other train is on standby. This dryer skid package included a wet air receiver tank, auxiliary cooler, water separator, duplex air pre and after filters with a nine (9) valve by pass system and heatless regenerative desiccant air dryers.

This package was designed to withstand one of the harshest environments in the Middle East complete with sandstorm protection to all the equipment. This package also went into Class I Div 2 environment (considered a hazardous area or harsh operating environment) with NEMA 7 type enclosure and HART protocol instruments. The capacity of each dryer train is 265 scfm @ 138 psig with air quality of -400F pressure dew point. This package was string tested with the Atlas Copco Compressors, which were also skid packaged with this project.

 

Atlas Copco Air Package

Instrument air CDE 250+ skid package included a sandstorm protection package. Components included a wet air receiver tank, auxiliary cooler, water separator, duplex air pre and after filters with a nine (9) valve by pass system and a heatless regenerative desiccant air dryers.

 

Chemical plant in Texas: 7100 scfm Heated Purge Desiccant Dryer with custom Allen Bradley PLC

The next project was for an olefins and polymer manufacturing chemical plant. This facility had an older compressed air dryer requiring replacement due to its’ age and the capacity increase at the facility. This ADE3350 dryer is a heated purge desiccant dryers capable of handling 7100 scfm at the inlet of the dryer.

This dryer package was designed according to the customers’ strict specifications; complete with a man way incorporated into the vessels for inspection purposes and custom Allen Bradley PLC system and program to control the dryer. This dryer package was designed for outdoor use with severe duty paint and special instruments suitable for outdoor installation. This package also has pre and after filter package with a bypass system for the entire dryer package.

 

Atlas Copco ADE

A rear view of the ADE 3350 heated purge desiccant air dryer designed for 7100 cfm inlet 

 

Alumina refinery in the Middle East: Heatless desiccant dryer skid with actuated ball valves

One of the recent dryer skid packages that we designed and shipped was for an Alumina refinery in the Middle East. This dryer is a heatless desiccant dryer with duplex pre and after filters and 9 valve by pass system. Normally all dryers are equipped with cycle tested actuated butterfly valves but this project required actuated ball valves as per the customer requirements. Few of the other main customer requirements were the noise level must be maintained below 85 dBA even during blow-off cycle as well as the installation of a vortex enclosure cooler to cool and avoid contamination of the control panel enclosure from dirt. This dryer package is also installed outdoors.

This package also has smart instruments, cable trays for the electrical wires and controlled by Atlas Copco’s state of the art monitoring system called Elektronikon®. A sonic nozzle is also part of this package to avoid damage to the desiccant during excessive flow conditions.

Atlas Copco CDE

A CDE1100+ heatless desiccant dryer skid with duplex pre and after filters and a 9 valve by pass system

 

Chemical plant in Louisiana: Blower purge desiccant dryer for 12,700 cfm

A dryer package, currently in production at Atlas Copco’s Houston facility, is a blower purge desiccant dryer BDE6000+ for an ethane cracker and derivatives chemical plant in Louisiana. This dryer’s inlet flow capacity is 12,700 scfm and is designed for outdoor use in a Class 1 Div. 2 Gr B, C, D T3 Environment. This dryer comes with 100% redundant inlet and outlet filter packages with zero pressure loss drains, high performance butterfly valves to control tower switching for the large flow rates, a custom programmed PLC and high performance instrumentation.

The regeneration blower is configured for low noise and the package is equipped with flow meters to enable the customer to take full advantage of the turndown capabilities of the dryer. This package can thus easily adapt to continuously changing flow demands, giving the customer more flexibility in operating their instrument air system. The large heater, in this package, has also been rated for the hazardous area class and the control system has multiple layers of control and redundancy in order to ensure a high level of operational safety. This package’s footprint is approximately 36 feet long and 14 feet high, on a single skid with a simple lifting scheme.

 

Atlas Copco Blower

A 12,700 scfm BDE6000+ blower purge desiccant dryer (currently in production) for an ethane cracker and derivatives chemical plant

Rental Fleet

Apart from the above-mentioned dryer packages, which are designed for chemical refineries and power plants, the Atlas Copco Houston facility also produces rental air dryers used in pipeline, chemical refineries, power plants and other industries all over the world. Our most common rental dryer model has a 1600 scfm inlet flow capacity and incorporates pneumatic controls. The after-cooler used is also air-controlled. This enables our customers to use our dryers with no power supply. The frame is designed to allow forklift access on all sides and is a very robust machine used in the harshest conditions. All the material used in this dryer have been selected to maximize service intervals and reduce operating and maintenance costs.

Atlas Copco RentalAir

The rear view of a PHS1600 rental compressed air dryer skid with an air-controlled after-cooler.

 

The Atlas Copco- Houston facility has successfully designed and installed many more custom packages worldwide at a wide variety of customer locations. Every package is very unique and special in its own way. We take pride in our team’s competence and the equipment which comes from our facility.  Atlas Copco is always committed to our sustainable productivity and more importantly our, customers.

 

For more information please contact Ramsaran Palaniappan, Project Engineering Supervisor-Regenerative Desiccant Dryers, Atlas Copco Compressors at tel: 281-594-5027, email: ramsaran.palaniappan@us.atlascopco.com, www.atlascopco.us.

For similar Compressed Air Treatment Technology articles, please visit www.airbestpractices.com/technology/air-treatment.