M.A. Selmon Company, Inc.: Latest News

Sludge Control in Cooling Towers

Fri, 20 Dec 2024 15:34:02 +0000

The automated system releases the altered water in the drip tray and replaces it with fresh water until continuous measurement shows that the medium in the drip tray shows conductivity below the limit value.

Tech Hacks

Mon, 07 Nov 2022 09:52:43 +0000

Cannot Draw Straight Arrows or Circle with IPHONE - After drawing arrow or circle keep HOLDING down and it will lock in perfect circle and arrows.

Merriam Hart Communicator not working - Make sure 250 Ohm resistor is in SERIES with negative terminal and not across terminals. Make sure device is HART compliant.

Google Chrome will only cast current screen - BEFORE choosing device. Choose DESKTOP and then choose Monitor and it will move to all displays.

TIVO not receiving all channels - Unpower TIVO box, remove cable card, re-insert Cable card, repower box

Clamp-On Oxygen Flow Saves Lives!

Thu, 03 Jun 2021 15:11:32 +0000

The COVID-19 pandemic has caused long-term strain on hospitals and medical equipment, sparking concerns about the limitations of oxygen flow and existing VIE (Vacuum Insulated Evaporator) telemetry. The drastic rise in ventilator use and ICU occupancy has increased demand for these measurements and caused NHS hospitals in the UK to recognize the value of live O2 flow rate telemetry in inpatient care.

Clamp-On FLEXIM O2 flowmeters meters can help. By clamping directly to the hospital MGPS or BMS system, they provide a non invasive method of displaying live oxygen consumption data and alerting hospital workers to potentially dangerous O2 levels. Usage in each ward as well as peak and average flows can all be recorded in order to minimize patient risk and optimize O2 managment.

Clamp On Ultrasonic Flowmeters increase Chiller Efficiency and reduce Pump energy cost

Tue, 27 Dec 2016 15:34:10 +0000

An HVAC system’s energy efficiency is only as good as the energy-engineering firm that monitors and upgrades it. Hemant Mehta’s WMGroup must be doing something right because he and his team have been fine-tuning HVAC systems for the same major New Jersey pharmaceutical company since 1984.

Chiller Upgrades

The latest improvement involved the upgrading of the chiller systems at the company’s 100-acre research and development campus.

Two central chiller plants provide cooling water to buildings across campus. Plant #1 consists of five 1,050-ton, three 800-ton, and one 500-ton constant-speed electric centrifugal chillers, plus one 950-ton steam-fired double-effect absorption chiller.

Plant #2 consists of four 1,050-ton and one 500-ton constant-speed electric centrifugal chillers, plus one 950-ton steam-fired double-effect absorption chiller and two 680-ton steam-fired single-effect absorption chillers.

Chilled water had been distributed from each plant via a primary/secondary/tertiary pumping system. Dozens of pumps circulated water in the primary loop within the plant (constant flow), secondary loop from the plant to the buildings (variable flow), and tertiary building loops (variable flow).

Mehta’s team determined that the pumping system was over-designed considering the technology available today. The result was excessive pump horsepower and wasted energy throughout the cooling season. He made a presentation to management that proposed converting the chilled water systems to a variable-volume primary-only pump system, by reconfiguring piping in the plant and at the buildings and upgrading plant controls. This would eliminate the need for 42 pumps, simplify operation of the system, and save pump energy as well as substantial chiller energy with improved staging.

Within each plant, one constant-speed pump (ranging from 40-75 hp) would run per operating chiller, circulating water through the primary loop. The secondary pumps’ variable-frequency drives (VFDs) modulate their speed (flow) to maintain a differential pressure set point in the system. Most of the buildings have variable-speed tertiary pumps, which pull water from the secondary loop supply and send it through the air handling units (AHUs) in their buildings. After the job was completed, only one set of variable-speed pumps was needed to provide flow for cooling generation and distribution to the buildings.

“We estimated the total cost of the project at $1.8 million and an annual savings in power usage of approximately $400,000,” said Mehta. “That would make a return on investment of more than four years. But, we also found a way to make it more affordable — New Jersey’s Clean Energy Program (CEP).”

The CEP offered a program called Large Energy Users Pilot that offered financial incentives for entities to improve their energy efficiency, and the pharmaceutical manufacturer certainly qualified as a large user. Mehta and his team worked up energy-efficiency plans detailing the pump replacement, submitted them to the state, and they were accepted. They qualified for more than $700,000 in incentives.

“That incentive dropped my client’s investment to just over $1 million and shortened the ROI to about two-and-a-half years,” said Mehta. “The project was approved and began about a year ago. It was completed in May.”

Pump Savings

In addition to the electrical energy saved by eliminating 42 constant flow pumps, the variable-flow pumps further reduce water flow and energy usage throughout the newly revised system, because only the water flow required by the load is chilled and delivered. With a variable-flow primary-pumping system at the majority of loading conditions, no chilled water is returned back to the chiller, without being used by the load.

Varying the water flow through the chiller has many benefits. It allows production-pump energy savings and compressor energy savings during partial load operation. The quick unloading capabilities of variable-capacity compressors makes varying water flow through the chiller possible, because a consistent outgoing water temperature can be maintained over a variety of loading conditions. This reduces the likelihood of nuisance trips of the chiller safeties, which prevent the chiller from freezing, and it also optimizes performance of the chiller system.

It is necessary to include a supply-water bypass with modulating valve and return water-flow sensor with variable-flow primary pumping systems. During low load conditions this system ensures a minimum water flow through the chiller. The modulating valve and return water-flow sensor only allow the bypass to be used at low-load conditions to maximize energy efficiency at other loading conditions.

Varying the water flow through the chiller also minimizes the efficiency losses during low ΔT syndrome conditions. To combat a low ΔT, a variable-flow primary-pumping system can vary the water flow through the chiller to optimize efficiency.

Flow Measurement

Increasing chiller efficiency is certainly important, but equally important is the ability to measure the flow of the water throughout the system.

“You cannot manage what you don’t measure,” said Mehta, “so it was critical to have accurate flow measurements. But we needed to get it at the most economical way possible without sacrificing accuracy. In a new plant, I typically recommend magnetic flow meters because they offer good accuracy. But this was an old plant, and mag meters are intrusive, so the plant would have to be shut down and the pipes would have to be cut to install them. That would be expensive.”

Tim Kusters, account manager, Technical Devices Inc., a process control instrumentation representative, had been supplying ultrasonic flow meters, among other instrumentation, to the pharmaceutical company’s facility manager for years. That is where he heard about the WMGroup chilled-water optimization project.

“They had originally specified mag meters,” said Kusters. “The Flexim flow meters we recommended clamp directly on to the pipes with no need to shut down the plants and cut into the pipes. Also, there were some flow measurement points with very short, straight runs. Clamp-on ultrasonic meters are capable of using multiple beams which mitigate the effects of short pipe runs. With this capability, we were able to guarantee flow meter accuracy comparable to, or better than, mag meters. Mehta and his team chose the ultrasonic meters because they provided a significant savings in installation costs and provided excellent accuracy. While we knew that this application was for the chilled-water optimization, we were told they would likely expand the project in the near future to include the monitoring of condenser water from the cooling tower. So we installed dual-channel electronics everywhere to take advantage of the fact that we could later tie in the condenser water on the second channel of the electronics/transmitter. The 25 Flexim meters we installed communicate with the plant’s SCADA system via BACnet. When the condenser water was added, it was much more economical because they didn’t have to wire and power an additional transmitter because a two-channel ultrasonic meter can measure the flow in two pipes.”

Ultrasonic Technology

The technique that Flexim’s ultrasonic flow meters use is called transit-time difference. It exploits the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium, kind of like a swimmer swimming against the current. The signal moves slower against the flow than with it.

When taking a measurement, the meter sends ultrasonic pulses through the medium, one in the flow direction and one against it. The transducers alternate as emitters and receivers. The transit time of the signal going with the flow is shorter than the one going against. The meter measures transit-time difference and determines the average flow velocity of the medium. Since ultrasonic signals propagate in solids, the meter can be mounted directly on the pipe and measure flow noninvasively, eliminating any need to cut the pipe.

When first introduced, ultrasonic meters were met with skepticism, as one problem justified that doubt. The couplant grease that sealed the transducer to the pipe would migrate out over a few years and the meter would fail. Flexim solved the problem by developing a non-grease solid-pad couplant. Because of their success in the field, ultrasonic flow meters are now accepted as a highly accurate, nonintrusive measurement system.

Measuring Savings

To verify the electric energy savings resulting from the variable pumps, a whole-facility approach used electric utility data and cooling load trend data. Energy use (kWh) was normalized for the cooling generated in the same period (ton-hours). The efficiency of the cooling system before and after the improvements (kW/ton) was compared.

Pre-Project Usage

A cooling-load profile that was developed for the facility based on available trend data from both chiller plants, which spanned from 2010-2011, was the basis of the energy-savings calculations. The total ton-hours of cooling used in each month was plotted against the corresponding monthly energy use from the utility meters. A linear regression showed the base monthly energy use that is not attributed to cooling. This energy was subtracted from each month and the remainder was totaled for the whole year, yielding the annual electric energy consumption of the cooling system. This was divided by the total ton-hours generated during the same period to get the average system efficiency in kW/ton.

After the Project

After the variable pumps were in use, the energy management system trended the cooling load on the chiller plants for a minimum of six months. The monthly ton-hours were totaled and plotted against the coincident electric energy use from utility meters. Another regression was run and the base monthly energy use was subtracted from the utility totals. The remaining electric energy use was totaled for the period, along with the ton-hours, and the subsequent variable-pump cooling system efficiency was calculated.

“The savings were in line with what we had estimated when we came up with estimated savings of $400,000 per year,” said Mehta. “One example of increased efficiency can be seen in chiller usage during the unusually hot summer of 2012. In the past, our client would need all of his chiller capacity in the summer, and have none in reserve, hoping no system shut down. Last summer, with the upgraded chiller systems in use, they had at least three systems in reserve.”

Using Clamp-on Ultrasonic Flowmeters for Accurate Helium Measurement

Tue, 30 Aug 2016 09:16:21 +0000

Since 1996 the demand for helium has been ramping up, as supply remains fairly static. Accordingly, prices have risen sharply. For example, in 2014 the price for crude helium is estimated to increase 30 percent.

The culprit? The Federal Government in the guise of the Bureau of Land Management (BLM)

Properties of Helium The helium atom is smaller than that of any other element and second only to the hydrogen atom in lightness. As a result, helium is chemically inert and does not form stable compounds with other elements. The attractive forces between helium atoms are also so weak that helium has the lowest liquefaction temperature of all the permanent gases and, unlike all other elements, does not freeze under its own vapor pressure as the temperature is lowered toward absolute zero. Helium turns to liquid at -268.93 C. Absolute zero is -270 C, making helium the very best element for super-conducting applications.

The Federal Reserve The first large-scale use of helium for nonscientific purposes was its substitution for hydrogen as a lifting gas in lighter-than-air applications (e.g., dirigibles, zeppelins, and blimps). Even though hydrogen provides about 7 percent more lift than helium, it is much more dangerous to use because it is highly flammable. The military importance of helium as a lift gas in the early 20th century led to the development of the Federal Helium Reserve in 1925.

Losing Money
By 1995 the reserve was $1.4 billion in debt as a result of earlier purchases of helium from private producers and their practice of selling helium below market rates. The debt was due to finally be repaid to the U.S. Treasury Department by the fall of 2013 and, under current law, funding to the federal program would then stop, terminating operations. The BLM assumed market forces would move in to fill the gap. That happened, but at a much slower rate than was anticipated. The anticipated closing of the Bush Dome would have a significant impact on numerous industries throughout the world—everything that uses computer chips, MRI machines, aerospace, super cooling, and scientific research. That meant that the cost of many things would rise dramatically.

A Solution—Kind Of Fortunately, Congress acted and in September 2013 passed the Helium Stewardship Act that keeps the reserve going and provides a formula that gives guidelines for pricing relative to current market prices.

The problem was that helium prices were at an all-time high. Helium refiners had already been raising prices in anticipation of the Bush Dome’s closure. There were other helium plants and storage facilities in the works, but their completion and production were still years away. There was no choice but for businesses to find ways to conserve and learn to work smarter.

Helium Conservation Strategies Ever since the space shuttle program was cancelled, NASA and the Kennedy Space Center have been rebranding themselves. While they will continue to build and launch spacecraft for exploration and other government projects, the earlier single-minded focus on the shuttle program has broadened. NASA has now taken its sprawling complex and is essentially leasing space and capabilities to tenants. While those tenants consist mostly of subsets of NASA working in different areas of aerospace, two are private companies—SpaceX and United Launch Alliance—and there are likely to be more in the future.

“It used to be that the only customer we had was the shuttle program,” says Dan Tierney, sustaining systems engineer for URS Corporation, a contractor working with NASA at the Kennedy Space Center. “Since they were the sole user of everything that was supplied, there was no need to monitor usage. Now that the shuttle program has ended and NASA has various customers, we need to bill each one separately for everything we supply them. For liquids and gasses that meant that we had to install metering.

“For a variety of reasons, the two most difficult flows to measure are nitrogen and helium gas,” says Tierney. “Both are vital in rocket and spacecraft use. Nitrogen is a propellant and helium has three uses. It is used to remove atmospheric moisture from cleanroom facilities. Because helium is an extremely small molecule and can find its way through the tiniest opening, it is valuable as a leak detector on spacecraft. Third, it is used in high volumes in launch support. Since helium will not freeze upon expansion, as most gasses will, it is used as a purge gas to sweep out combustible vapors from rocket engines and engine compartments. We call it ‘safing’.”

Enhanced metering was seen as a way to optimize helium use. Helium [is&91; very expensive—10 times the cost of nitrogen, so conservation is key.

URS performed a major search for meters that could not only measure gas, but also gas at low flow rates. “While many of the meters provided acceptable accuracies, operating and maintenance costs played a big factor,” says Tierney. “All but one of the meter types was intrusive and had to be exposed directly to the flow.” That meant an expensive installation, as well as costly maintenance. Because the meters were exposed directly to the flow, they would experience wear. “That meant that down the road, we would have to shut down, remove the meter, clean or replace parts, and start up again,” says Tierney. “That added greatly to the long-term cost.”
The chosen meter in this case was a clamp-on ultrasonic meter by FLEXIM, which didn’t have to be exposed to the fluid flow stream and showed a high accuracy at all flowrates.

Transit-Time Ultrasonic Flowmeters Applied“The technique most ultrasonic flowmeters use is called transit-time difference. Transit-time ultrasonic flowmeters exploit the fact that the transmission speed of an ultrasonic signal depends on the flow velocity of the carrier medium, kind of like a swimmer swimming against the current,” says Peter Chirivas, an engineer at FLEXIM Americas, the maker of the meter selected. “The signal moves slower against the flow than with it.”

Semiconductor Two East Coast semiconductor manufacturers also opted for ultrasonic metering, but for different applications.
“We use helium in the chip making process,” says Anne, a professional engineer at a major Mid-Atlantic chipmaker. “We use it as a shield gas in clean rooms to keep pollutants off the wafers and as a push gas because it is inert.

“With the cost of helium going up for the foreseeable future, we knew we had some leaks in the system,” says Anne. “We compared our tool data to our flowmeters and we had a mismatch. We were missing some gas and we weren’t sure where it was going. We needed a way to detect the leaks so they could be sealed. Helium can get through the tiniest opening.”

The first time Anne heard of ultrasonic metering as a leak detector was at the Chem Show at the Jacob Javits Center in New York City. “There aren’t that many clamp-on flowmeters that will read gas accurately at a low level,” says Anne. “We had looked at ultrasonics before and we did buy a unit some time ago, but it didn’t have leak-detection capability and it was permanently installed elsewhere.

“We needed something we could use on the distribution network that led to the chip-making tools,” says Anne. “If we put flowmeters on every line it would cost a small fortune, not to mention the production loss from the downtime it would take to install the meters.”

The FLEXIM meter we chose was portable and worked on all of the pipe sizes. It also measured slow flows very accurately. “We’ve been going to each lateral and totalizing the flow over a particular period of time,” says Anne. “Then we compared that to the tool’s mass flowmeters. When we first rented the FLEXIM meter, we compared its performance to our building flowmeters. And the FLEXIM meter was quite accurate.”

After going lateral by lateral and comparing the ultrasonic flowmeter’s results to the tools’ mass flowmeters, the manufacturer identified a leak in one of the tools fairly early in the process. “We put the FLEXIM on and the background levels stayed too high for the flow,” says Anne. “We got a window to shut down each tool and went one-by-one until we found it. So we were able to find and repair a leak with little-or-no loss of production.”

Jack Sine is a freelance writer specializing in petrochemical, HVAC, flow technology, and environmental issues.

Brad Selmon provide instruments to Customer and supported Application Research for this Article

Dynamic Load Compensation for Dry Block Temperature Calibration

Wed, 01 Jun 2016 11:27:55 +0000

JOFRA is continuously seeking new ways of improving temperature calibration. The DLC calibration correction technology is yet another state of the art innovation within temperature calibration. DLC is short for Dynamic Load Compensation: the principle is innovative and patent pending.

What is the Dynamic Load Compensation system?

The Dynamic Load Compensation system combines a measuring/control system with a newly developed Dynamic Load sensor.

What is the purpose of the Dynamic Load Compensation?

The DLC system has been developed to deal with a major contributor to calibration errors. A dry-block used as a calibration instrument has some inherent error mechanisms. It is a fact that the sensor under test will affect the calibration accuracy during calibration. The sensor transmits energy to and from the calibrator. This heat exchange between the calibrator and the environment has a considerable negative impact on the calibration accuracy. The extent of the error depends on many factors: sensor size (diameter and length), number of sensors in the well and the difference between calibration temperature and ambient temperature.
In other words, calibration accuracy is actually influenced by the actual load of the calibrator.

How does the DLC system work?

JOFRA temperature calibrators are already famous for their active dual-zone calibration principle.
With the DLC system, we have taken this well-proven and acknowledged dual-zone principle one step further. The load compensation is now active both within the heating block and inside the insert during calibration.
The DLC sensor measures the actual temperature difference between two defined points inside the insert. See the purple dots. The DLC sensor is designed to process input to the heat control system of the calibrator to ensure that the axial gradient deviations in the lower 60 mm of the insert are kept to a minimum. The temperature difference between the bottom and the zone at 60 mm from the bottom is controlled within a few hundreds of a degree.
The DLC system reacts immediately to changes in the load of the insert and controls the heat distribution to achieve the minimum axial gradient.

How much does the DLC system improve your calibration results?

The DLC system improves the calibration accuracy significantly. This may be illustrated and proven by two different test scenarios.
The first scenario shows the improvements when measuring in the insert. The graph below illustrates the temperature change in the insert as a function of the distance from the bottom. Ideally this should be a straight line with no temperature variation vertically in the insert. If so, the axial gradient would be zero. However, this is not the case in practice.
To prove that the DLC functionality will improve the axial gradient, three tests have been performed.
The first test is to put a very light load on the RTC calibrator, which should produce a very little axial gradient (blue line). The load is a 4 mm external reference sensor, a 3 mm sensor and the DLC sensor. The maximum deviation from the ideal straight line is 0.015°C.
The next test is to load the RTC calibrator more heavily (red line). A thicker, 10 mm, sensor is added to the configuration detailed in the previous test. The DLC functionallity is not activated. The heavier loading of the calibrator causes a nonlinear axial gradient. The maximum deviation from the ideal straight line is 0.160°C.
The last test is carried out with exactly the same load as above, but we will now activate the DLC functionallity to see how efficiently the DLC will straighten the gradient (green line). The maximum deviation from the ideal straight line is 0.025°C.

What are the advantages of the patent pending DLC system?

Calibration of several sensors simultaneously
Calibration of large diameter sensors
Since no standard temperature sensors have a thermo sensitive lenght beyond 60 mm, it is no longer necessary to know the length of the thermo-sensitive part of the sensor. Just plug it in!
The DLC indicator shows that the dual-zone is active and working
A perfectly working calibrator. The DLC value is very close to 0.00 when the calibrator is loaded or not loaded
Calibration value indication. The DLC indicator shows when the temperature homogeneity in the lower 60 mm part is achieved

What are the important benefits for the user?

• Saves time by calibrating more sensors simultaneously

• Calibrating big diameter sensors without loosing accuracy due to heat conduction

• TSL (Thermo Sensitive Length) independency. Safe, secure and accurate calibration results without spending time to get sensor specifications from your supplier

• The DLC function minimizes the influence from sensor production tolerances like the Pt100 element being mounted in various positions in the sensor

• All temperature sensors that can be placed in the bottom of the calibrator will be calibrated without error

• The displayed DLC value indicates when the optimum temperature homogeneity is achieved

• The displayed DLC value shows when the load has no influence on the calibration result

• When the DLC value is close to zero, the calibration technician knows that the calibration results are reliable

• The DLC indicator proves that the dual-zone is active and well-functioning

• The DLC in conjunction with the stability indicaton show when the calibration value is ready. The green-zero rule

Problems Associated with High Vibration and Pulsation Service in Pressure Measurement

Sun, 15 May 2016 23:36:07 +0000

Pressure gauges without gears are known as "Direct Drive" gauges.
Direct-drive pressure gauges replace the “C-shaped” bourdon tube and gears in a standard gauge with a unique helically wound bourdon. The helical bourdon is coupled directly to the shaft pointer, which is the only moving part. Fewer moving parts translates to fewer gauge problems. Regular recalibration is eliminated because there are no complex, wear-prone parts... like linkages, gears and sectors. Linearity is built-in; no span adjustment is necessary. Accuracy is maintained throughout the life of the gauge, which is much longer than standard gauges. Overpressure ratings are typically 150% of span which prevents calibration shift and the helical bourdon tube will typically withstand spikes of 500% of span without bursting. Helical bourdon tubes are typically made of Inconel, which is a highly elastic material with excellent corrosion resistance.
We compare 3D Instruments Direct Drive versus Liquid Filled Gauges.

In many severe applications “C-shaped” pressure gauge cases are filled with a liquid to dampen their movements and increase service life. Besides adding cost to the gauge, the liquid fill causes other problems... loss of accuracy, discoloration and added maintenance difficulties. 3D Instruments applies a high viscosity silicone dampener, known as GAD, directly to the outer layers of the bourdon tube. This GAD dampens the pointer movement in severe vibration and/or pulsation based applications thereby eliminating the need for liquid fill. In most instances a standard 3D Instruments Accu-Drive Gauge will easily replace a traditional liquid filled gauge. The 3D gauge will provide longer service life and lower field maintenance costs. When compared to liquid filled gauges, 3D Instruments gauges can last as much as 10x longer in severe vibration and pulsation service. Using 3D Instruments Accu-Drive Gauges will have a dramatically favorable impact on your gauge cost of ownership.

CHP Gaining Widespread Interest Reduced Costs, Accurate Metering, and Freedom from the Grid are Key

Thu, 05 May 2016 12:13:45 +0000

In recent years, there has been growing interest in combined heat and power (CHP), also called cogeneration. CHP works by using modular turbines connected in parallel to generate electrical power on site, capturing the heat created, and using it to heat the facility in winter, and drive an absorption chiller in warm months.

So, why is a technology that has been around since Edison creating interest from industries as diverse as manufacturing, shopping malls, and health care? Three reasons: efficiency, money, and independence.

Incentives

CHP systems capture heat when generating electricity, making them markedly more efficient than typical public utilities that do not. A natural gas-fired power plant operates at around 35 percent efficiency. By capturing and using the heat generated by a CHP system’s turbines, CHP users are able to achieve efficiencies in excess of 90 percent.

“There is a growing awareness of energy consumption and energy costs,” said Peter C. Houck, former assistant general manager of Related Urban. “The demand for energy optimization, energy management, and energy measurement is huge.”

Related Urban is a developer and manager of premium properties that owns the retail portion of Time Warner Center in New York City. The Time Warner Center qualified for financial incentives from New York State Energy Research and Development Authority (NYSERDA). They put the money to good use, winning the Building Operators and Managers Association (BOMA) International Building of the Year Award.

“The incentives for going cogen aren’t just in New York,” said Brad Selmon, president of M.A. Selmon Co., an East Coast rep firm specializing in control instrumentation and accessories.

“I believe all states have similar programs. I recently helped a major Massachusetts sporting goods manufacturer convert to CHP by setting them up with ultrasonic flow metering. They got federal and state incentives in the hundreds of thousands of dollars. It worked so well, they are installing a CHP unit at another site and getting similar incentives.

“The metering was key to qualifying because you have to be able to verify to the state how much you are reducing your carbon footprint.”

Money

Of course, incentives are essentially money, but there are other ways to save money (or avoid wasting it) and it all comes down to measurement. For instance, in 2008, Related Urban wanted to upgrade its metering system at the Time Warner Center. The original flow meters had been inside the piping and degraded over time from continuous contact with hot and chilled water. They opted for ultrasonic, but were very cautious. Most of the metering would be submetering for their retail clients’ heating and air conditioning use. Related Urban wanted consistent accuracy so they weren’t underpaying itself or overcharging its clients for heating and air conditioning. The company’s experience with intrusive metering led it to look into clamp-on ultrasonic metering.

“While the company was naturally concerned with peak usage flows of heated and chilled water, it also was very concerned with off-peak measurements,” said Izzy Rivera, product sales engineer for Flexim Americas Corp. “The company had done its homework and knew that measuring peak flows with ultrasonic technology was a fairly established practice. It was the low flow rates during off-peak when the businesses were closed for the day that would make the difference. Intrusive meters would be able to measure low flow rates accurately until they began to degrade, but the lion’s share of ultrasonic meters would fail miserably when flow rates slowed. Fortunately, we had already had some challenging experience with measuring slow flow rates.

“A few years ago, a company named Coastal Monitoring Associates had come to us. They specialize in monitoring ground water contamination to keep clients within EPA [Environmental Protection Agency&91; standards,” said Rivera. “The meter they used in their patented technology had been discontinued, and they wanted to know if our ultrasonic technology could do the job.”

Peter Chirivas, an engineer at Flexim, called it a really interesting challenge. “No one at Flexim had ever thought about measuring such slow flows. We had developed the capability to measure gases, liquids, slurries, and all of them over a wide range of temperatures. But they had never tried extra slow flows.

“Coastal hydrologist Ron Paulsen and I worked on the challenge after hours. Coastal’s need was clear and we wanted to be of help. To our surprise, one of our existing meters really did well. We made some adaptations to further improve accuracy and got down to the 1-2 percent range. It worked so well, we now incorporate the technology in a variety of our other meters. We were ready when Related came calling. Related initially bought 28 meters to measure points for physical plant management and the company was pleased with the meters’ performance, Related ordered an additional 50 to submeter their retail clients.”

Sizing Systems

“We had tried ultrasonic metering before without success,” said Dale Desmarais, sales and marketing manager for Aegis Energy Services Inc., a manufacturer of modular CHP systems.

“We sell our systems directly to end-user facilities and also through third-party developers. Because of our TVI [True Vertical Integration&91; we can provide a full turnkey project, ‘CAD [computer-aided design&91; to completion.’

“We also have the ability to install the system for free and charge for the electric and heat we produce through our shared savings program. We deliver electric savings from 10-15 percent versus the public utility, so it is critical that we accurately size our system. The original ultrasonic meter we tried was attractive because it installed on the outside of the pipe and saved us significant time. But, it was not reliable and was extremely inaccurate on slow flows. One of our core values is, ‘Deliver on what we say we will do,’ and if we were to oversize an installation, we would not be able to utilize the heat and would not give the customer the savings they expect.

“When we heard of Flexim’s low flow capability, we gave it a try. The results were so accurate that we now use one in most every application,” said Desmarais. “The importance of the ultrasonic meter is that it is extremely valuable to us as we do not need to dedicate other resources, such as the time to identify and hire a qualified plumber, schedule and perform the work, and pay the costs associated with installation of an in-pipe meter. Banks and investors, owners, CFOs, facility engineers, and energy service companies all rely on this accuracy to execute results on their projects, and the Flexim Btu meters are what Aegis relies on to help deliver as promised.”

Independence from the Grid

A final advantage for incorporating CHP technology either as the prime means of electrical power, heat, and cooling, or as a backup, is that your business is no longer dependent on the power grid. If you haven’t actually experienced black outs and brown outs, you have read of their devastating effects. And now we have the added threat of terrorists. Nearly every day we hear of how vulnerable the grid is to terror attacks. So, as long as accurate measurements are included, CHP adds up to a win-win for most everyone involved.