Blowdown Tanks in Steam Systems

Schematic for applying blowdown tank in steam system.
Image courtesy Colton Industries

Blowdown, in a steam system, serves as a means to remove condensate or reduce the accumulation of minerals and contaminants in a boiler. The temperature and pressure of the effluent precludes its discharge into most municipal sewers, requiring a means to collect the discharge and reduce its temperature prior to final disposal.

A blowdown tank is designed as a receiver which vents flash steam to atmosphere and provides for cooling of the condensate prior to final discharge. A vent connection at the top of the tank is normally routed to a safe discharge location outdoors. In some cases, a condenser may be applied to the vented steam. The condensate collects in the tank and cools as heat is radiated from the tank walls, generally steel or stainless steel. Faster cooling can be accomplished with the incorporation of a thermostatic cooling valve that mixes cold water with the condensate.

The blowdown tanks have no moving parts and few requirements for maintenance. Good practice calls for periodic inspection for wall erosion and corrosion. An inspection hatch provides access to the tank interior.

Share your steam system requirements and challenges with specialists, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.

Steam System Blowdown Tanks from MSJacobs-Cali

Improved Level Measurement Contributes to Reduced Heat Rate in Steam Production

Minimizing heat rate and emissions for steam plants

Steam production is a costly operation in any facility, but is of paramount importance in power generation plants. The bottom line of a combustion based power generation facility is sensitive to the cost of input fuel. Measures that can be taken to reduce fuel input for a unit of power output (called heat rate) can translate directly into profitability. An additional benefit of reducing heat rate is a commensurate reduction in emissions.

A major contributor to heat rate reduction is the recovery of heat from the process and transference of that heat into the boiler feedwater. A sizable feedwater preheater of the shell and tube type is used to recover the heat. Shell and tube heat exchanger efficiency can be maximized with accurate control of liquid level.

Magnetrol, globally recognized leader in level measurement technology, makes the case for using guided wave radar level measurement technology as the most advantageous means for this application. The video below describes the process and how the guided wave radar level transmitter can provide the best performance.

Magnetrol has an information kit devoted to heat rate reduction. Share your steam system and level measurement challenges with a product specialist, and ask how you can get the Heat Rate Reduction Kit. Combining your facility and process knowledge with the product application expertise of a specialist will result in effective solutions.

Conductivity Controller For Boiler Applications

Conductivity controller for boiler applications
Lakewood Instruments

Modern boilers using the Rankine cycle require feedwater and make-up feedwater quality maintained within certain limits with respect to alkalinity, conductivity, and other factors in order to maintain boiler operating efficiency and minimize maintenance requirements.

Controlling the feedwater quality can be accomplished with the addition of controlled amounts of the right chemicals to regulate various aspects of water quality. Another method is to purge, or blowdown, the boiler in a measured fashion that allows fresh feedwater to replace overly contaminated water. Filtration, which I generally deem to include ion exchange, reverse osmosis, and mechanical filtration, is a third method. All deal specifically with a limited scope of contaminates that have an impact on boiler operation and longevity.

Boiler blowdown can be used to limit the amount of total dissolved solids in the boiler drum water. As water boils, the dissolved solids in the water concentrate in the remaining liquid water. Blowdown purges a portion (or all) of this water, allowing the addition of water, presumably treated, with substantially lower total dissolved solids.

Boiler blowdown has an energy cost, since the replacement water must be heated to the design condition. It follows that executing this procedure should be undertaken when necessary, but not more frequently. A conductivity monitor and controller can accomplish properly timed blowdown cycles. The system consists of a conductivity sensor and a control unit that provides all the necessary functionality in a single integrated package. A data sheet is included below for one such unit from Lakewood Instruments.

Share your boiler operation challenges with an instrumentation specialist an explore how a properly instrumented steam system can provide operational savings and extended time between failure.

Water Treatment Controller For Boiler Applications from MSJacobs-Cali

Building Steam System Efficiency for Profitable Returns

Improvements in steam system efficiency can yield
substantial return on investment

Steam, an energy efficient, reliable, scalable form of transferring heat, is utilized throughout commercial, industrial, and institutional settings. The ubiquitous adoption and use of this heat transfer medium has resulted in steam generation ranking as a substantial line item on any organization's financial operating report. The scale of many steam production operations can produce some sizable payback opportunities from modifications that improve efficiency or reduce maintenance requirements.

The application of modern precision measurement instrumentation is one area where comparatively modest investments in system improvement can yield ongoing returns. Magnetrol International, a globally recognized leader in the design and manufacture of flow and level instrumentation, has produced a white paper describing aspects of the steam cycle that are candidates for profitable improvement and how various measurement technologies can help garner the maximum attainable gain in efficiency.

The paper is included below, and will prove to be informative and interesting reading. More information is available on specific instrument recommendations from product application specialists. Share your steam system challenges with them and work together to find the best solutions.

Optimizing the Steam Generation Cycle and Condensate Recovery Process from MSJacobs-Cali

Positive Returns From Steam Generation and Condensate Recovery Efficiency Gain

Steam systems are excellent candidates for cost saving
through increased efficiency.

The generation of steam is a lifeblood operation to many commercial and industrial operations around the world. The large scale of its use can make steam generation one of the largest energy consumption activities for an industrial plant or commercial building. The size and complexity of steam systems, with generation, condensate handling, heat recovery, and feedwater treatment, provides a number of areas where inefficiencies can cost very substantial sums of money. Conversely, enhancing efficiency toward a maximum attainable level will yield very large savings in operating costs.

Magnetrol International, a globally recognized leader in the design and production of flow and level controls for commercial and industrial use, has produced a video summarizing the elements of the steam system that are good candidates for upgrade, as well as general direction on how to achieve increased efficiency for each. In keeping with the company's line of level and flow measurement products, the focus is on how accurate and robust instrumentation can improve overall system performance and generate a decidedly positive return on the time and funds invested.

Invest a few minutes in the video below and learn how the operating efficiency of your steam system can be elevated with an instrument upgrade. There is a white paper on the same subject available on request. You can also receive a listing of the specific Magnetrol instruments that can be applied to steam systems, with a short description of where each is applied. Reach out to a product application specialist and share your steam system challenges. Combining your system knowledge with their product application expertise will yield the best solution.