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Category Archives: Case Studies

 

The PCC-IV loop controller is the next generation of Preferred’s loop controllers AND upgraded technology for the entire industry. The PCC-IV is more flexible, has extensive memory, and not only replaces the Preferred PCC-III, but also can replace the Siemens Moore 352 and 353, obsolete and no longer supported starting October 2017.

Preferred Utilities’s controls are just that- preferred. Consider a case study of a longtime PCC controls customer:

Preferred Utilities has been supporting this facility in New York since 1988 with our PCC II and III loop controllers. This site installed one PCC-IV and is now considering this next generation of upgrade, the PCC-IV, in their plant with four (4) 50kpph boilers, each with steam, gas, and oil flow meters.

In 1988, the facility installed 16 PCC-IIs and 5 control panels, plus field instruments for a burner/controls upgrade. Almost 10 years later in 1997, they updated the system with the purchase and installation of 17 PCC-IIIs. In 2002, they decided to upgrade again and add O2 trim. Satisfied with the Preferred product, they installed 21 of the PCC-III units.

Now, in 2017, the plant installed a PCC-IV in parallel with one of the PCC-III controls to observe the performance and is considering upgrading the rest of the PCC-II and PCC-III controls. With the auto-converting functionality of the PCC-IV, the existing PCC-III programs can be re-used without modification and re-programming.

Preferred Utilities is pleased to offer generations of quality products that age gracefully and come with a pledge of full service support and solutions for upgrades in the future.

PCC-IV Loop Controller Front

PCC-IV Loop Controller internal

 

 

 

A New Jersey paper mill came to Preferred Utilities recently needing a quote for a new burner for their 1961 Preferred Utilities Unit Steam Generator. What is wrong with their existing Preferred burner? Nothing. The plant is being forced to convert from No. 6 heavy fuel oil to natural gas.

Will their next burner last 56+ years? Maybe. It depends on who they buy it from.

Note, Preferred still had the documentation on the existing burner and boiler. But we had to go to 49 year Preferred veteran engineer Ricky Erickson to find it.

This plant needs a Low NOx burner that meets the emissions regulations in New Jersey. Preferred designs and builds burners that can meet the strictest regulations, and provides configurable NOx settings, “future-proofing” them against lower emissions requirements that states may adopt in the coming years.

Built for the environment. Built to last.

 

 

Last summer a facility in Texas spilled 3,500 gallons of diesel fuel intended for one of their emergency generators. The fuel was pushed up through a day tank vent, ran across their parking lot, and into a pond adjacent to their property. The clean-up team recovered about 2,100 gallons of fuel out of the pond, but at a cost of about $300,000.

I was called to the site two weeks after the spill and took these pictures of the pond. It’s amazing how resilient nature can be in Texas. The only damage I could see to the pond was browned grass below the waterline. Now, ten months later, the pond appears to have fully recovered.

 

The generator fueling system for this facility was installed in 2013. From an inspection of the day tanks, all the instrumentation and safety devices met the required NFPA and local fire codes. However, I did not recognize the systems integrator who did the PLC controls. I suspected there was an error in the PLC program exacerbated by a system design that didn’t anticipate something going wrong.

 

The facility owner brought in a couple of sharp corporate engineers to autopsy the existing controls. They found errors in the PLC programming logic. A level sensor failed, showing a low fuel level in the day tank, so the PLC controls energized supply pumps to re-fill the day tank from the main storage tank. With the level sensor stuck, the PLC controls ignored all the other instrumentation indicating the tank was full, continued pumping fuel, and quickly overfilled the tank. The facility engineers thought the system started pumping fuel at about midnight. Facility staff coming on duty at 7 a.m. smelled diesel fuel, noticed the fuel on the ground, and shut off the pumps.

 

At first glance, the control sequences for diesel generator fueling systems are not terribly complicated, so local systems integrators are often hired to provide controls for fueling systems. However, to ensure fuel is always available to mission critical emergency generators, and fuel spills are prevented, the Preferred engineers—who specialize in the design of generator fueling systems—try to anticipate every likely failure mode:

 

–What happens if a level sensor gets stuck?

–What happens if an analog transmitter fails and produces 0 milliamps?

–What should the controls do if a pump fails to prove flow?

–What happens if there is a break in a fuel line, or a tank starts to leak?

–What happens if an operator manually energizes a fuel transfer pump and then goes home?

 

After supplying so many fueling systems over the years, all of these failures will happen. Regardless of a component failure or operator error, fuel spills are still unacceptable, and the generators still need fuel.

 

I did boiler controls for twenty years before learning how to design and commission fuel handling systems. NFPA boiler code dictates all the safety devices and sequences required to operate boilers. As a result, at least three separate devices must fail to run the water out of a boiler, or overpressure a boiler. NFPA code for fueling systems is much less specific. In fact, the fuel system that caused the spill at this facility didn’t violate any NFPA fuel handling codes.

 

In the end, this facility’s Preferred installer and consulting engineer commissioned the new Preferred fuel handling system controls. Commissioning is the process of simulating all the “What happens if…” scenarios described above and verifying the fuel system responds correctly to all imaginable upset conditions.

 

It’s the last thing we do on every fuel handling project.

David Eoff, BSME, MBA

Preferred Utilities, National Sales Manager

 

What happened the last time your house lost power? That email you were writing might have had to wait an extra half an hour, and your refrigerator might have warmed a few degrees. At most, ordinary power outages represent a minor annoyance to the home or office.

The situation is different at the massive data centers of the world. Amazon now sells over 600 items per second, and their systems are designed to accommodate up to 1,000,0000 transactions per second. At this scale, a 20 minute power outage at one of the data centers powering its store could cost Amazon millions of dollars in lost revenue.

To avoid this sort of catastrophe, the world’s big data centers strive to meet the Uptime Institute’s “Tier-Standards,” specifying various levels of guaranteed data processing availability, reliability, and redundancy. Meeting these standards requires avoiding single-points of failure — all components must have redundant backups.

One of the most critical components, of course, is the power supply system: without power, the flow of data grinds to a halt. Although massive data centers pull their power from the public electric grid, they must have redundant systems of backup power ready to go. Stored power in batteries is important, but the real backup system is the diesel generator.

Managing the reliability and redundancy of their generator systems is a significant challenge for data centers. It’s an unfortunate reality that components break and systems fail tests. At many data centers, the fuel system supplying the generator will have components from a legion of vendors, not one of whom will understand (or take responsibility for) the whole system. This can make troubleshooting routine systems failures a nightmare.

Working with a company that provides a fully integrated system is essential – from the fuel tanks and pump systems to the monitoring devices and control systems. Therefore if a problem arises, data centers have a single support call to make. A single source contact will understand how the pieces work together and can quickly solve problems. It’s the difference between working with a parts manufacturer with a few engineers on staff, and an engineering design firm that manufacturer’s the parts.

At Preferred Utilities we specialize in fuel systems—it’s what we do all day, every day—we pride ourselves on designing reliable systems that reduce the need for support calls in the first place. Data center engineering teams are generalists and great at looking at the big picture, so when it comes to fuel systems, they often aren’t able to immerse themselves in the details the way our engineers do. We know the code compliance specs, how to make sure the tank size is correct, and how to optimize virtually any scenario to help data centers at all Tier levels to keep the their fuel, power, and data flowing.

If your company or industry requires this kind of technical expertise, you can reach Preferred Utilities Manufacturing Corporation at (203)-743-6741. We are dedicated to your success. People. Products. Results.

 

Boiler Control RetrofitIn conjunction with Puerto Rico representative M.R. Franceschini Inc., Preferred recently replaced an existing flame safeguard and oxygen trim system with the Preferred BurnerMate Universal (BMU) system on a 500 HP boiler at a pharmaceutical plant outside of San Juan.

In addition to oxygen trim, the BMU is controlling the forced draft fan variable speed drive (VSD), and providing first out annunciation of boiler trips. The BMU was integrated with the existing proprietary feedwater control system and all existing boiler limits.Boiler Control Retrofit with BMU

This steam boiler runs continuously on No. 2 oil, which is expensive in Puerto Rico, so the boiler was tuned for the lowest excess air possible at all firing rates to reduce fuel consumption.

In addition to expensive fuel, Puerto Rico has some of the most expensive electricity rates in the U.S. according to the U.S. Energy Information Administration. Industrial users in Puerto Rico currently pay an average of 14.6 cents/kW-hr compared to the national average of 6.54 cents/kW-hr.

Rate hikes averaging 26%BurnerMate Universal have been announced effective in 2017 for the island. With the new Preferred BMU controller, the forced draft fan VSD speed was kept under 30 Hz from low fire to mid-fire, resulting in electricity savings of over 85% compared to 60 Hz operation.

For more information on the BMU Boiler Control System, click here.

 


How much will you save?
Check out the Preferred Utilities Energy Savings Payback Calculator

Ever tried to justify a retrofit project? Now there’s a better way to crunch the numbers. This app will save you time and money. It analyzes your existing boiler and burner system data and compares it against a proposed modern upgrade, complete with energy savings estimates.

The calculation output in this application is extensive. It includes a fuel analysis, combustion efficiency (existing and projected), fuel consumption, electrical consumption, and C02 credit calculations. Use this tool if you are considering a boiler/burner upgrade.

Used for:

  • Boiler retrofits
  • Burner upgrades
  • Control upgrades
  • Energy auditing

Features:

  • Save your work
  • Recall past projects
  • Print your data
  • Compare Preferred equipment

Energy Saver Payback Tool

 

Carrolton, Texas — By David Eoff

It seems the new buzzword for our industry is Mission Critical. It’s the name of a trade magazine that caters to data centers. It’s also a term marketers use when they want to impress upon people that their equipment is installed at important facilities.

Preferred Utilities recently did a fuel oil project at a building that might be termed mission critical. This building will house the airline communication center (ACC) for one of the largest airlines in the country. The FAA requires that airlines be in constant communication with all their active planes at all times.

If they lose communication with a plane, that plane can’t fly. If it’s in the air, the plane has to land. If the airline’s ACC loses power, all their planes are immediately grounded. Losing communications with aircraft would require the airline to ground its fleet, resulting in a huge negative impact across the national airspace system.

Emergency Generator

The building that houses the ACC is on grid power. But it also has three generators, each with it’s own over-sized belly tank. The airline wanted this building to be tornado resistant, so the generators, belly tanks, and fuel supply system is all below grade. We provided Model 3 fill boxes so even the fill lines for the belly tanks are underground.

The generator to the left is one of three that can provide power for the building if the grid power fails. The Preferred PWC-based fuel controller provides tank gauging, leak detection, and overfill protection for the belly tanks for the three generators.

The image to the bottom right shows tank 1 being filled during final construction of the building. The Preferred system provides tank volume display at the fill port, as well as an overfill alarm at 85% full, and will shut off the fill line at 95% full.

Underground Fill Tank

Each generator has enough fuel to power the building for at least 24 hours. In addition, the airline pays a steep premium to be high priority for fuel delivery trucks. Their priority level is just below local hospitals in an emergency. The facility people have my cell phone number too. I live 20 minutes from the building and will respond if something goes wrong.

But who says that mission critical systems can’t be pretty, too? In addition to being tornado resistant, the Preferred Model 3 fill boxes can be hidden behind mulch and shrubberies to offer an aesthetically pleasing appearance. Look at the photo below if you don’t believe us.

 

Underground fill tank
 

Side panelFood Processing Plant Saves Money by Burning Alternative Fuel

 

Many processing plants produce large amounts of waste water, causing plant owners to rethink their energy use strategy. In 2013, a mid-western US food plant found a way to use its own waste water as an alternative energy source.
When the city of Janesville, WI began constructing an anaerobic digestion system at its waste water treatment facility, the city created a contract to sell conditioned biogas back to the food plant.
Using its own conditioned biogas, the food plant unlocked the ability to burn self-produced alternative fuel. But in order for the project to be a success, the plant needed a combustion system capable of handling such a unique demand. Based on prior success with a similar plant., the plant owner’s turned to Preferred Utilities and a team consisting of Leidos Engineering, LLC and American Boiler.

 

Preferred Utilities designed and supplied a complete combustion system, including an API-800 Burner, a bio/natural gas mixture piping train, and a proprietary burner management/combustion control system.
The system was designed to burn either natural gas alone, or a mixture of preferential biogas and supplemental natural gas. Because digester gas contains sulfur and water, Preferred fashioned 316 stainless steel for all burner and piping components to resist corrosion. The combustion system’s startup and operation procedure is governed by a BurnerMate TS burner management/combustion control system.

 

The system consists of Preferred Instruments DCS-III digital controllers and a GNE 5004-M-85 Flame Safeguard module. The plant now employs a full metering combustion control strategy with FD fan, VFD control, and oxygen trim. The combustion air demand is determined based on the sum of the combustion air requirements established by the inputs of both the natural gas and biogas flow rates.

 

The combustion system now fires a natural gas/biogas mixture, with priority given to biogas based on availability established by supply pressure, thus maximizing fuel cost savings for the food processing plant.

 

 

Side panel

Boiler Controls Upgraded for Efficiency, Flexibility, and Reliability

 

Ford Motor Company sought to upgrade its burner management and combustion control systems at its research and engineering powerhouse in Dearborn, MI.

With the support of local representative D.J. Conley Assoc. Inc., Preferred Utilities upgraded several multi-burner boilers from manual to automatic firing rate control within the guidelines of NFPA 85.

 
Originally a 4-burner manual system firing natural gas, Preferred’s PLC-based BMS, PCC-III controllers, and DCS-III Controllers now allow for successive burners to be automatically lit-off or stopped based on load demand. Sequencing of burners is now made by way of a burner firing order” selection screen.

Furthermore, operators can now choose either Warm-up or Hot Standby mode. Warm-up mode holds one or two burners at low-fire until the boiler reaches its minimum flue gas temperature. Once reached, the firing rate and additional burners will light-off or shut down based on load demand.

Hot Standby holds one or two burners in the same manner, but once the flue gas temperature is met, the burners shut down and the boiler is tripped.

Preferred provided more upgrades, including dual 15-inch touch screens, “igniter only” mode and sequencing flexibility for operators. A fully-metered, cross-limited fuel-air ratio control with FD fan VSD and Oxygen Trim control provides for improved combustion efficiency. 3-element feed water and 2-element draft controllers provide for reliable operation.

 

 

A year after Hurricane Sandy, engineers are rethinking designs for subterranean equipment. Preferred Utilities Manufacturing Corporation has created a solution that should limit the power outages that plagued mission critical facilities during the destruction of Hurricane Sandy. That solution is the waterproof pump.

Designed for areas in flood zones, the pump attaches to back-up generator equipment. The state-of-the-art submersible pump is designed to withstand complete submergence in water and continue uninterrupted operation.

The pump and its motor assembly are securely welded within the enclosure to ensure operation during full submersion. It also features flexible stainless steel hoses for pump suction and discharge connections, a flanged access door with gasket, a sliding tray for pump removal, maintenance, or repair, all of which are encapsulated in an epoxy-enamel painted steel enclosure.

  •     More Features:

o    Discriminating type leak sensors installed inside enclosure
o    External connections seal welded to enclosure for connection of field piping.
o    External connections seal welded to enclosure for electrical connections
o    Local non-fusible disconnect installed within the enclosure.

  •     Potential Applications:

o    Any facility where equipment is installed at or below historic flood levels and they cannot afford to lose electrical power generation.
o    Locations prone to flooding with backup power systems.
o    Hospitals, financial institutions, communication facilities, data centers.

Although Sandy weakened to a Category 1 hurricane by the time it struck New York and New Jersey, its storm surge caused massive flooding in streets, tunnels, and subway lines, resulting in lost power. While power losses were expected with a storm this large, many of the backup generator systems were not designed to operate under large amounts of water. The back-up generators failed under the immense amount of water, [leaving many important facilities without power, like the NYU Langone Medical Center.

If you need to rethink your mission critical fuel delivery strategy, don’t wait for the next storm–call Preferred today, or visit us at http://www.preferred-mfg.com

Preferred Utilities is the single-source umbrella for all mission critical needs. Services include customized engineering, consultation, installation, and scheduled maintenance.
Products include fuel oil handling systems, boiler equipment, burners, nuclear components, flow modeling services, and more. Our products can be found in commercial, institutional, industrial, and nuclear facilities.