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  • Expand Wireless Technology In Your Steam System to Improve Efficiency

    In recent years, wireless technology has made a significant impact to improve industrial steam system operations, cut energy waste and enhance safety. As the technology has continued to advance, expanding the use of wireless networks and sensors has become dramatically more cost-effective as compared to wired alternatives, with faster installation time and minimal disruption. Here are a few of the technologies we highly recommend:

    SteamEye Steam Trap Monitoring

    Let’s face it, at any given time a percentage of your steam traps have failed, and you just don’t have the staff to test them frequently. Besides, the trap you check on Tuesday may fail Wednesday — and not be scheduled for a recheck until next year—leaving the median time of discovery at 6 months. With an average steam trap failure rate of 5% - 20% that can add up to significant energy losses. SteamEye is a steam trap monitoring system that uses a wireless transmitter to detect temperature and ultrasonic fluctuations in steam flow. It uses a radio frequency (RF) wireless transmitter mounted at the inlet of any type of steam trap to detect temperature and ultrasonic fluctuations in steam flow. A central receiver then alerts system operators of trap failure. Here are two scenarios where Steam Eye has made an impact:

    • Scenario 1: Reducing Failure Rate
      • A large university had over 4,300 steam traps located over 13.9 miles of underground steam and condensate lines and 2.3 miles of utility tunnels. Their steam trap failure rate was nearly 25% so they chose to install SteamEye monitors which measures and manages their steam trap data to improve the steam system and maintenance of the steam traps. As a result, the university has reduced steam consumption while increasing their campus footprint, lowering lowered their steam trap failure rate from 25% to 1.4%.
    • Scenario 2: Hospital cuts steam consumption
      • A large hospital, built in the 1950s, faced the high cost of getting steam from the city's steam loop and desired to cut energy costs. To identify where steam loss was occurring they installed a SteamEye monitoring system. A full steam trap survey was conducted and they retrofitted 76 high and medium pressure steam traps. The hospital was able to cut steam consumption by an average of 4,000 pounds per hour with a substantial savings. The customer also recognized a simple payback within two years of installing SteamEye.

    AIM - Armstrong Intelligent Monitoring (Acoustic and Temperature)

    Three constant challenges that plant managers and maintenance personnel face in the operation of any system include:

    1. Identifying a failure: ability to immediately pinpoint what has failed, when it failed and where it failed.
    2. Evaluating the scope: comprehending the magnitude of the failure related to process and utility systems.
    3. Measuring the impact: accurately calculate the costs including process disruptions, wasted energy andplant shut downs, safety hazards and fines levied.

    AIM enables your team to tackle all three challenges with one wireless system solution that combines a mix of methods including acoustic and temperature monitoring. Here are three scenarios where AIM has provided pinpoint detection and notification of failures:

    • Scenario 1: Condensate Back Up Caused by Steam Trap Malfunctions
      • The customer was experiencing problems with multiple steam traps that caused condensate to back up into their steam turbine. This issue caused severe downtime and decreased performance, directly affecting their bottom line. After installing AIM on the affected steam traps, the customer was made aware of the problem and were able to react immediatly before condensate back up became an issue. 
    • Scenario 2: Leaking Isolation Shut Off Valves
      • The customer experienced problems identifying the location of a leaking isolation shut off valve. When leaking shut off valves bypass materials for critical process, production efficiency decreases significantly. AIM was installed to acoustically monitor and identify when and where leaks occurred along the line. If a potential leak was identified, the customer would be immediately notified to avoid even more leakage.
    • Scenario 3: Pump Trap Failure
      • Pump trap failure caused condensate backup, flooding coils and process equipment, causing harm to the customer’s steam system and equipment. An AIM system was installed to wirelessly monitor the skin temperature of any pipe, vessel or piece of equipment. As a result, early detection of reduced inlet condensate temperature to the pump trap allowed the customer to prevent potential failure.

    AIM helps you work smarter by anticipating your needs and taking the guess work out of system troubleshooting enabling you to address problems before they spiral out of control.

    Wireless HART

    More HART products are installed in more plants around the world than any other. AIM works through a centrally located wireless gateway that enables real time, 24/7 monitoring. It easily connects and organizes WirelessHART devices to your host system while providing security, scalability, and data reliability. HART's wireless technology allows users to access the vast amount of unused information stranded in these installed smart devices. It also provides a cost-effective, simple and reliable way to deploy new points of measurement and control without the wiring costs.

    Work Smarter - Not Harder

    According to research*, wireless technology can provide: 

    • 60% less cost per device - less cabling and conduit, calibration-free, no training and low power
    • 65% less time per device - less engineering, non-intrusive, faster commissioning, quick deployment, easy integration
    • 95% less rack room footprint - no junction boxes, marshalling cabinets or input/output cards

    Campbell-Sevey offers an extensive line of wireless solutions to fit your industrial applications. Contact us to learn more about wireless options and how you can take advantage of the benefits going wireless provides.  *Emerson

     


  • Steam Tip 23: Automatic Blowdown-Control System

    To reduce the levels of suspended and total dissolved solids in a boiler, water is periodically discharged or blown down. High dissolved solids concentrations can lead to foaming and carryover of boiler water into the steam. This could lead to water hammer, which may damage piping, steam traps, or process equipment. Surface blowdown removes dissolved solids that accumulate near the boiler liquid surface and is often a continuous process. 

    Suspended and dissolved solids can also form sludge. Sludge must be removed because it reduces the heat-transfer capabilities of the boiler, resulting in poor fuel-to-steam efficiency and possible pressure vessel damage. Sludge is removed by mud or bottom blowdown. 

    During the surface blowdown process, a controlled amount of boiler water containing high dissolved solids concentrations is discharged into the sewer. In addition to wasting water and chemicals, the blowdown process wastes heat energy, because the blowdown liquid is at the same temperature as the steam produced—approximately 366°F for 150-pounds-per-square-inch-gauge (psig) saturated steam—and blowdown heat recovery systems, if available, are not 100% efficient. (Waste heat may be recovered through the use of a blowdown heat exchanger or a flash tank in conjunction with a heat recovery system. For more information, see Steam Tip 10, Recover Heat from Boiler Blowdown.) 

    Advantages of Automatic Control Systems 

    With manual control of surface blowdown, there is no way to determine the concentration of dissolved solids in the boiler water, nor the optimal blowdown rate. Operators do not know when to blow down the boiler, or for how long. Likewise, using a fixed rate of blowdown does not take into account changes in makeup and feedwater conditions, or variations in steam demand or condensate return. 

    An automatic blowdown-control system optimizes surface-blowdown rates by regulating the volume of water discharged from the boiler in relation to the concentration of dissolved solids present. Automatic surface-blowdown control systems maintain water chemistry within acceptable limits, while minimizing blowdown and reducing energy losses. Cost savings come from the significant reduction in the consumption, disposal, treatment, and heating of water. 

    How it Works 

    With an automatic blowdown-control system, high- or low-pressure probes are used to measure conductivity. The conductivity probes provide feedback to a blowdown controller that compares the measured conductivity with a set-point value, and then transmits an output signal that drives a modulating blowdown release valve. 

    Conductivity is a measure of the electrical current carried by positive and negative ions when a voltage is applied across electrodes in a water sample. Conductivity increases when the dissolved ion concentrations increase. 

    The measured current is directly proportional to the specific conductivity of the fluid. Total dissolved solids, silica, chloride concentrations, and/ or alkalinity contribute to conductivity measurements. These chemical species are reliable indicators of salts and other contaminants in the boiler water. 

    Applications 

    Boilers without a blowdown heat-recovery system and with high blowdown rates offer the greatest energy-savings potential. The optimum blowdown rate is determined by a number of factors, including boiler type, operating pressure, water treatment, and makeup-water quality. Savings also depend upon the quantity of condensate returned to the boiler. With a low percentage of condensate return, more makeup water is required and additional blowdown must occur. Boiler blowdown rates often range from 1% to 8% of the feedwater flow rate, but they can be as high as 20% to maintain silica and alkalinity limits when the makeup water has a high solids content. 

    Price and Performance Example 

    For a 100,000 pound-per-hour (lb/ hr) steam boiler, decreasing the required blowdown rate from 8% to 6% of the feedwater flow rate will reduce makeup water requirements by approximately 2,300 lb/hr. (See Steam Tip Sheet #9, Minimize Boiler Blowdown.) Annual energy, water, and chemicals savings due to blowdown rate reductions for a sample system are summarized in the table below. In many cases, these savings can provide a 1- to 3-year simple payback on the investment in an automatic blowdown-control system. 

    Purchasing and installing an automatic blowdown-control system can cost from $2,500 to $6,000. The complete system consists of a low- or high-pressure conductivity probe, temperature compensation and signal conditioning equipment, and a blowdown-modulating valve. Some systems are designed to monitor both feedwater and blowdown conductivity from multiple boilers. A continuous conductivity recording capability might also be desired. The total cost of the automatic blowdown system is dependent upon the system operating pressure and the design and performance options specified. 

    This tip is provided by the U.S. Department of Energy - Energy Efficiency and Renewable Energy. For suggested actions and resources, click to download the complete US Department of Energy Tip Sheet.  

     


  • Manual Tank Heating to Improve Cycle Times

    Recently Hydro-Thermal shared an interesting case study about a Wisconsin chemical facility that was looking to improve their cycle times and the quality of their chemical product. The time to fill a water tank for mixing in the production process had become a barrier in the production cycle, and it was difficult for the current shell and tube heat exchanger to obtain the desired water temperature. There were also maintenance and energy issues associated with the current heat exchanger and condensate return system.

    SOLUTION

    Hydro-Thermal helped install a H2015 EZHeater® with a Medium diffuser on the production site. The EZ Heater® provided numerous advantages to the chemical company. The production crew was surprised by how easy it was to obtain the exact water temperature required for each individual product formula. Production cycle time was decreased, but more importantly, the temperature of the water was obtained much faster than in the past, which resulted in better end-product. Finally, the maintenance crew was elated by the reduction of maintenance time.

    GOAL

    • Improve cycle time
    • Improve product quality
    • Replace aging shell and tube heat exchanger
    • Eliminate condensate return system issues

    ACCOMPLISHMENTS

    • Installed H2015 EZ Heater with Medium Diffuser
    • Easy temperature control for different formulas
    • Decreased production cycle time
    • Improved product quality
    • Reduced maintenance 

    If you'd like to learn more about EZ Heater or Hydro-Thermal's patented direct steam injection technology, contact the team at Campbell-Sevey

     


  • Case Study: Minnesota Veterans Home Takes Advantage of Rebates to Install TVS and Steam Eye

    The Minnesota Veterans Home in Minneapolis, located on a 53-acre wooded campus, provides long-term care to veterans in 291 skilled nursing beds and 50 domiciliary beds in private and semi-private rooms. 

    Renewed Steam Distribution Interest

    With the addition of some new staff, the Minnesota Veterans Home had a renewed interest in the efficient operation of their steam distribution system. They understood that a single leaking safety valve or failed steam trap with an orifice even the size of a BB can cost thousands of dollars in steam loss annually. 

    In addition, the site wanted the capability of monitoring their trap population and steam safety valves continuously to ensure on-going and recurring energy savings. To reduce project costs, rebate programs from the local natural gas utility, CenterPoint Energy, were utilized to partially fund the project.

    Using Trap Valve Stations & Steam Eye

    The team at Campbell-Sevey performed a steam trap and safety valve survey to gather and update missing or incomplete equipment data. New steam traps were then installed throughout the campus. Based on the site’s preference, all steam traps in drip service were replaced with Armstrong’s Trap Valve Stations (TVS), which have many benefits including:

    • Reduced costs. TVS saves by eliminating potential leak points and reducing installation and maintenance time.
    • Multiple functions. TVS has integral positive-shutoff isolation valves, strainer, and strainer blowdown valves.  
    • Easy, in-line repairability with maximum safety. TVS allows positive-shutoff isolation at the point of service with verifiable trap depressurization for safety prior to opening the trap for service.
    • SteamEye compatible TVS. TVS is fully compatible with the SteamEye monitoring system.

    Armstrong’s SteamEye Steam Trap Monitoring System was also installed on every steam trap and steam safety valve. This system resides on their computer network and will monitor the condition of every trap and safety valve continuously. When failures occur, it will notify system operators instantly, reducing the time from failure to repair from years to minutes.

    For more information on Campbell-Sevey's steam trap and safety valve surveys, or to see if Trap Valve Stations or SteamEye Monitoring is right for your system, contact the team at Campbell-Sevey.

     

  • Campbell-Sevey Offers Continuing Education Credits

    For steam, air and water industry professionals seeking continuing education credits (CEU's) Campbell-Sevey offers some great options. 

    Campbell-Sevey Steam Seminar

    Our Steam Energy Conservation Seminar helps you make your steam system as efficient as possible. This 1-day interactive seminar helps you gain knowledge and improve your skills as textbook information is converted into practical field applications on a “live steam system” at Campbell-Sevey’s offices in Minnetonka, MN. Through the use of glass piping, glass models, and cut-away parts, you will get a live look at how a steam systems behaves across various elements. Click for complete course details, agenda and registration information.

    Armstrong University Courses

    Campbell-Sevey also collaborates with Armstrong International to offer CEU’s and college credits for professionals seeking to expand their knowledge about energy, steam, air, hot water and utility systems. The collaboration combines the extensive knowledge of Campbell-Sevey to create custom curriculum through Armstrong University – engaging online courses that spans more than 10 colleges and 100 courses of study. 

    The on-demand learning makes it easy to learn from the convenience of a desktop, tablet or smartphone. With our help in designing a curriculum you can ensure that what you are learning can be applied directly to your system. Click for more information and a complete list of all the colleges and courses offered.

    For more information about all of our education offerings, contact the team at Campbell-Sevey

     

  • Get a Free Heat Shield Energy Survey

    Free Energy Survey uses thermographic imaging to illustrate heat loss.

    Shannon is the market leader removable, reusable blanket insulation. To promote the highly lucrative performance generated by insulating complex surfaces with their blankets, they are teaming up with Campbell-Sevey to offer a Free Energy Survey. The Energy Survey is the key driver behind developing an ECM (Energy Conservation Measure) for Thermal Blanket Insulation. The key behind a comprehensive survey approach is having the knowledge and experience to find and to know what to treat in a complex steam system. 

    Most insulation surveys address pipe and ignore the greatest opportunity, complex valves and fittings. Shannon's team is trained in steam process systems and energy survey fundamentals, knowing exactly where the great opportunities for energy savings are located and most importantly, compiling the field data so you have knowledge of where your system is wasting energy.

    The Energy Survey Proposal will present bare surface radiant conditions, insulated surface performance, the potential energy savings from Shannon Thermal Blanket Insulation and most important, a summary of values which gain immediate approval from utility rebate programs (if one is available). 

    The Campbell-Sevey and Shannon Survey Approach:

    • Initial Field Survey ( Infrared and/or Thermal Graphic Imaging )
    • Compilation of the Field Data ( Spread Sheet of Tabulated Values )
    • Presentation of the Data and Summary of Values ( Simple Payback, ROI, IRR )
    • Calculation Conversions to Meet Customer Measures for Approval ( BTU, Therm, #/Hr Steam, HP )
    • Steam Cost & Utility Cost Measures
    • Rebate Incentives ( If Available )
    • Field Take-Off, Marking, Tagging, Measuring of each Itemized Fitting
    • CAD/CNC Design & Manufacturing ( For Exact Fit and High Quality Standards )
    • Installation Services ( Open Shop & Union Labor Installation )
    • Optional Measurement & Verification Post Completion Survey

    As a result of the surveys and subsequent blanket insulation installation, most ECM's see payback periods from 6 to 18 months depending on utility credits. 

    For more information about the program, download Shannon's Energy Survey brochure. Then contact Campbell-Sevey for information on scheduling a survey at your facility.


  • Test Your Knowledge: The Three Element System

    The three element system for controlling the boiler drum level considers which three parameters?

    1. Feed Water Flow, Fuel Flow, Liquid Level
    2. Feed Water Flow, Combustion Air Flow, Liquid Level
    3. Feed Water Flow, Fuel Flow, Steam Flow
    4. Feed Water Flow, Steam Flow, Liquid Level

    And the answer is...

    4. The "three element control" in boilers stands for the three control element, each measuring an individual process variables;

    • Flowrate of boiler feed water
    • Flowrate of steam leaving the boiler
    • Liquid level inside steam drum

    For any boiler, controlling the liquid level at the optimum range is the highest priority. It needs to be high enough to ensure that water is present in every steam generating tube, yet low enough to provide sufficient space for steam above the liquid. 

    For boilers operating at low pressure, it is relatively inexpensive to have a large steam drum in which the liquid level moves very slowly. But for boilers operating at medium or high pressure, larger steam drums are more expensive, so in most cases these steam drums are small. This means that liquid levels can fluctuate very quickly. To protect against this fluctuation, the three element control is typically used.

    Why 3 elements instead of 2 elements?

    Suppose we have a 2 element control which directly controls the flowrate of boiler feed water (by opening/closing control valve) based on the liquid level in the steam drum. If the level decreases, the control valve opening will increase to increase the flowrate of feed water. But lets say at the same time the steam requirement changes whichl fluctuates the steam drum pressure. 

    For instance, if the liquid level decrease in the steam drum that forces the control valve to increase the flowrate (suppose 50% to 70%) so that it will balance the system. At a result, steam consumption decreases and pressure increases in the steam drum. In this scenario the control valve opening will still remain 70% because it will not consider the decrease in steam flowrate. Therefore the 70% opening of the control valve will give the same flowrate it was getting before with the 50% opening. In this case, the 2 element control will not work.

    To avoid theissue, the 3 element control system is installed (the third element measures the steam flow rate). Now if the level in the steam drum fluctuates at the same time as the steam requirement, the steam flowrate signal will go into the flow controller of the boiler feed water and adjust the opening of control valve accordingly to get the desired flow of water inside the steam drum.

  • Did You Know We Have Parts Available for Same Day Shipment?

    Were you aware that we have local stock available for same day shipment?  We do!  

    Campbell-Sevey has local stock of part for the following manufacturers: 

    • Armstrong
    • Spence
    • Kunkle
    • Thrush
    • Durabla
    • Klinger

    Click here to access a complete list of all of our products. Then call our 24-hours parts and service line for technical support by phone at 952-935-2345.


  • Steam Tip 22: Consider Installing High-Pressure Boilers with Backpressure Turbine-Generator

    When specifying a new boiler, consider a high-pressure boiler with a backpressure steam turbine-generator placed between the boiler and the steam distribution network. A turbine-generator can often produce enough electricity to justify the capital cost of purchasing the higher-pressure boiler and the turbine-generator. 

    Since boiler fuel usage per unit of steam production increases with boiler pressure, facilities often install boilers that produce steam at the lowest pressure consistent with end use and distribution requirements. 

    In the backpressure turbine configuration, the turbine does not consume steam. Instead, it simply reduces the pressure and energy content of steam that is subsequently exhausted into the process header. In essence, the turbogenerator serves the same steam function as a pressure-reducing valve (PRV)—it reduces steam pressure—but uses the pressure drop to produce highly valued electricity in addition to the low-pressure steam. Shaft power is produced when a nozzle directs jets of high-pressure steam against the blades of the turbine’s rotor. The rotor is attached to a shaft that is coupled to an electrical generator. 

    Background 

    The capital cost of a back-pressure turbogenerator complete with electrical switchgear varies from about $900 per kilowatt (kW) for a small system (150 kW) to less than $200/kW for a larger system (>2,000 kW). Installation costs vary, depending upon piping and wiring runs, but they typically average 75% of equipment costs. 

    Packaged or “off-the-shelf” backpressure turbogenerators are now available in ratings as low as 50 kW. Backpressure turbogenerators should be considered when a boiler has steam flows of at least 3,000 pounds per hour (lb/hr), and when the steam pressure drop between the boiler and the distribution network is at least 100 pounds per square inch gauge (psig). The backpressure turbine is generally installed in parallel with a PRV, to ensure that periodic turbine-generator maintenance does not interfere with plant thermal deliveries. 

    Cost-Effective Power Generation 

    In a backpressure steam turbine, energy from high-pressure inlet steam is efficiently converted into electricity, and low-pressure exhaust steam is provided to a plant process. The turbine exhaust steam has a lower temperature than the superheated steam created when pressure is reduced through a PRV. In order to make up for this heat or enthalpy loss and meet process energy requirements, steam plants with backpressure turbine installations must increase their boiler steam throughput (typically by 5% to 7%). Every Btu that is recovered as high-value electricity is replaced with an equivalent Btu of heat for downstream processes. 

    Thermodynamically, steam turbines achieve an isentropic efficiency of 20% to 70%. Economically, however, the turbine generates power at the efficiency of the steam boiler. The resulting power generation efficiency (modern steam boilers operate at approximately 80% efficiency) is well in excess of the efficiency for state-of-the-art single- or combined-cycle gas turbines. High efficiency means low electricity generating costs. Backpressure turbines can produce electrical energy at costs that are often less than $0.04/kWh. The electricity savings alone—not to mention ancillary benefits from enhanced on-site electricity reliability and reduced emissions of carbon dioxide and criteria pollutants — are often sufficient to completely recover the cost of the initial capital outlay. 

    Estimating Your Savings 

    Since you have already determined that you need a boiler to satisfy your process thermal loads, the marginal cost of power produced from the backpressure turbine-generator is: 

    Cost of Power Production = (Annual Boiler Fuel Cost after Pressure Increase – Annual Boiler Fuel Cost before Pressure Increase)/Annual kWh Produced by Turbine-Generator 

    The cost of boiler fuel before and after a proposed pressure increase can be calculated directly from the boiler fuel cost, boiler efficiency, and inlet and outlet steam conditions. The annual kWh produced by the turbine generator can be calculated from the inlet and exhaust pressures at the turbine, along with the steam flow rate through the turbine, in thousand pounds per hour (Mlb-hr). 

    To estimate the potential power output of your system, refer to the figure below, which shows lines of constant power output, expressed in kW of electricity output per Mlb-hr of steam throughput as a function of the inlet and exhaust pressure through the turbine. Look up your input and output pressure on the axes shown, and then use the lines provided to estimate the power output, per Mlb/hr of steam flow rate for a backpressure turbogenerator. You can then estimate the turbine power output by multiplying this number by your known steam flow rate. 


    Example 

    A chemical company currently uses a 100-psig boiler with 78% boiler efficiency (E1) to produce 50,000 lb/hr of saturated steam for process loads. The boiler operates at rated capacity for 6,000 hours per year (hr/yr). The boiler has reached the end of its service life, and the company is considering replacing the boiler with a new 100-psig boiler or with a high-pressure 600-psig boiler and a backpressure steam turbine-generator. Both new boiler alternatives have rated efficiencies (E2) of 80%. The company currently pays $0.06/ kWh for electricity, and purchases boiler fuel for $8.00 per million Btu (MMBtu). Condensate return mixed with makeup water has an enthalpy of 150 Btu/lb. What are the relative financial merits of the two systems? 

    Step 1: Calculate the current annual boiler fuel cost: $3,200,000 per year 

    Current Boiler Fuel Cost 

    = Fuel Price x Steam Rate x Annual Operation x Steam Enthalpy Gain / E1 

    = $8.00/MMBtu x 50,000 lb/hr x 6,000 hr/yr x (1,190 Btu/lb – 150 Btu/lb) / (0.78 x 106 Btu/MMBtu) 

    = $3,200,000 per year 

    Step 2: Calculate the boiler fuel cost of a new 100-psig, low-pressure (LP) boiler: $3,120,000 per year 

    Resulting reductions in fuel costs are due solely to the higher efficiency of the new boiler. 

    New LP Boiler Fuel Cost 

    = Fuel Price x Steam Rate x Annual Operation x Steam Enthalpy Gain/E2 

    = $8.00/MMBtu x 50,000 lb/hr x 6,000 hr/yr x (1,190 Btu/lb – 150 Btu/lb)/ (0.80 x 106 Btu/MMBtu) 

    = $3,120,000 per year 

    Step 3: Calculate the boiler fuel cost of a new high-pressure (HP) boiler capable of producing 600 psig, 750ºF superheated steam: $3,318,300 per year 

    We must now take into account the additional enthalpy necessary to raise the pressure of the boiler steam to 600 psig. With a 50% isentropic turbine efficiency, the exhaust steam from the backpressure turbine is at 100 psig and 527ºF and must be desuperheated by adding 5,000 lb/hr of water. In order to provide an equivalent amount of thermal energy to the process loads, the boiler steam output is reduced to 45,000 lb/hr. 

    New HP Boiler Fuel Cost 

    = Fuel Price x Steam Rate x Annual Operation x Steam Enthalpy Gain / E2 

    = $8.00/MMBtu x 45,000 lb/hr x 6,000 hr/yr x (1,379 Btu/lb – 150 Btu/lb) / (0.80 x 106 Btu/MMBtu) 

    = $3,318,300 per year 

    Step 4: Estimate the electricity output of the steam turbine-generator: 6,750,000 kWh per year 

    At 600-psig inlet pressure with 750ºF superheated steam and 100-psig exhaust pressure, the system will satisfy existing steam loads but will also produce approximately 25 kW of electric power per Mlb-hr of steam production (you can use the figure on page 2 to estimate your power output for steam at saturated conditions). Thus, 

    Turbine-Generator Power Output 

    = 45 Mlb-hr x 25 kW/Mlb-hr 

    = 1,125 kW 

    Assuming a 6,000-hr operating year, the electricity output of this turbine will be: 

    Turbine-Generator Electricity Output 

    = 1,125 kW x 6,000 hr/yr 

    = 6,750,000 kWh/yr 

    Step 5: Determine the cost of electricity produced by the turbine: $0.029/kWh 

    The value is derived from the difference in fuel costs between the two boiler alternatives, divided by the power produced by the turbine: 

    Fuel Cost of Produced Electricity 

    = ($3,318,300/yr – $3,120,000/yr)/ 6,750,000 kWh/yr 

    = $0.029/kWh 

    Step 6: Calculate energy savings benefits: $209,250 per year 

    Cost Savings = 6,750,000 kWh x ($0.06/kWh – $0.029/kWh) = $209,250/yr 

    This level of savings is often more than adequate to justify the capital and maintenance expenditures for the backpressure turbine-generator set and the incremental cost of purchasing and installing the higher-pressure boiler. 

    This tip is provided by the U.S. Department of Energy - Energy Efficiency and Renewable Energy and originally adapted from material provided by the TurboSteam Corporation. For suggested actions and resources, click to download the complete US Department of Energy Tip Sheet.

  • Installing a Coil in a Tight Space? Try Banking

    So you're trying to install a new water coil in an older building. The challenge is the space just wasn't build for it. You could go to a smaller size coil, but that won't give you the performance you need. The solution? Banking!

    When dealing with tight, confined areas installing a bank of coils instead of a larger, single coil solves several issues:

    • Flexibility to fit tight spaces
    • Maintains optimum face velocity with proper design
    • Avoids potentially damaging larger coils during install

    A bank is basically a larger coil broken down into a series of smaller coils connected together and stacked. When installed correctly the bank will have the same performance as the larger, single coil.

    Important Design Requirements

    The way the smaller coils are configured can affect performance of the HVAC system. We configure cooling coils to have a maximum of 500 ft/minute face velocity to prevent water carryover. We also usually limit steam or hot water coil face velocity to 800 ft/minute as well for proper performance.

    Contact Campbell-Sevey for Options

    To make sure you get the ideal solutions for your HVAC system, contact the team at Campbell-Sevey. We can provide the design support and product solutions to best meet your challenge.


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Products We Carry

GENERATION
  • Hot Water Boilers
  • Watertube Steam Boilers
  • Firetube Steam Boilers
  • Deaerators
  • Heat Recovery Steam Generators (HRSG’s)
  • Automatic Recirculation Valves
  • Economizers
  • Gas-Fired Water Heaters
  • Gas-Fired Humidifiers
  • Boiler/Generator Flue Stacks
  • Continuous Emissions Monitors (CEMS)
DISTRIBUTION
  • Pressure Reducing Valves
  • Safety and Relief Valves
  • Control Valves
  • Pressure Independent Control Valves
  • Expansion Joints, Guides, Anchors
  • Flash Tanks
  • Flow Meters
  • Balancing Valves
  • Check Valves
  • Separators
  • Pumps
  • Pressure Booster Systems
  • Piston Valves
UTILIZATION
  • Heating/Cooling Coils
  • Plate and Frame Heat Exchangers
  • Shell and Tube Exchangers
  • Water Heaters
  • Steam Humidifiers
  • Vacuum Systems
  • Condensers
  • Steam Traps
  • Wireless Steam Trap Monitors
  • Tube Bundles
  • Direct Gas-Fired Space Heaters
  • Direct Gas-Fired Make-Up Air Units
  • Unit Heaters
  • Strainers
  • Air Vents
  • Liquid Drainers
  • Heat Transfer Packages
  • Digital Water Mixing Valves
  • Air Cooled Condensers/Dry Coolers
  • Steam Filters
RETURN
  • Electric Condensate Pumps
  • Steam/Air-Powered Condensate Pumps
  • Packaged Condensate Pump Skids