Showing posts with label power plant. Show all posts
Showing posts with label power plant. Show all posts

Kinetrol Vane Actuators Lower Cost of Filter Operation at Power Plant

A Monoscour® filter is a heavy duty, high-rate, gravity filter. It is designed for filtering high turbidity media and sticky particulates, and is commonly used in polymer chemical treatment, cooling tower side-stream filtration, and industrial wastewater filtering. This kind of filter is designed to be fully automatic and includes all piping and valves needed to change from filter mode to cleaning mode. Inexpensive rack and pinion actuators are installed as OEM components to divert flow between cycles. The actuators are mounted on 4" lug style butterfly valves.

A Midwestern power plant was experiencing failures with their filter's OEM rack and pinion actuators. The actuator cycle rate was moderate-to-high, approximately (1) cycle per hour, continuous.

While the cost of rack and pinion actuator replacement was relatively low, the cost of filter downtime and labor was very high for the utility. As part of an ongoing, long term cost savings effort, a more reliable and robust solution was required.

The local Kinetrol Distributor Salesperson was called in and immediately saw that replacing the rack and pinion actuators with Kinetrol vane actuators was the answer. Based on the countless applications around the world, where Kinetrol actuators perform reliably in the most challenging circumstances, this particular application was comparatively easy and straightforward.

The new Kinetrol actuators were retro-fitted to the existing valves with new mounting hardware and have been operating flawlessly for over a year now. Its expected the valves will wear out long before the actuators ever need service.

For more information about using Kinetrol vane actuators on filtration towers, contact Kinetrol USA by visiting or by calling 972-447-9443.

Monoscour® is a registered trademark of Graver Water Systems.

Upgrade in Steam Balancing Valve Actuators at Combined-cycle Power Plant Lead to Kinetrol

The customer for this application note is an electrical power station with a combined-cycle, natural gas-fired generating unit with two combustion turbines, two heat recovery steam generators and one steam turbine. The output of combustion turbines can vary at different times throughout the year. The nominal output for this facility is 577 megawatts. The station burns natural gas.

A combined-cycle power plant uses a gas and a steam turbine together to produce up to 50% more generated electricity, using the same fuel, when compared to a traditional simple-cycle plant. The gas turbine waste heat is routed to the nearby steam turbine which, in turn, generates the extra power.

One of the most common components for managing high-pressure steam in a combined-cycle plant is the HRH bypass valve (HRH stands for "hot reheat"). Since the valve actuator controls the valve’s ability to reliably and accurately respond to system demands, it can be argued it is one of the most important elements in the steam bypass system, and therefore the entire combined-cycle plant.

In this application, the customer had two 18" steam balancing valves using large, high torque, scotch-yoke actuators that had to cycle 20 times a day. These actuators presented significant performance issues (they were failing), plus they were very large which presented maintenance difficulties.

The customer approached the local Kinetrol USA Distributor and inquired if they could suggest a better alternative. The goal was to provide replacement actuators that provide very high torque, be highly reliable, and save space.

The Distributor recommended Kinetrol Model 30 pneumatic rotary actuators. The Model 30 provides 168000 lbf ins (19140 Nm) at 100 psi (7 bar) of torque and were significantly smaller and lighter than the legacy scotch-yoke actuators. Most importantly, they carried the world-renowned Kinetrol reputation for outstanding reliability, long life, and maintenance-free operation.

Kinetrol USA

Challenging Steam Balancing Valve Application at Southwest Power Plant

Steam Balance Valve
Steam balance valve
with Kinetrol model 30.
In combined-cycle power generation plants, the most common design for managing high-pressure steam is with cascading bypass systems. Balancing valves are used on the hot reheat line to respond to control loop demands. The application is difficult because of high pressures, high temperatures, and large valve sizes (high torque). The valves must shut off tightly and also be capable of precise throttling.

Outfitting these valves with pneumatic actuators is also difficult. Because of the valve size and valve design, actuators must have high torque output, without taking up vast amounts of space. The actuators must also act quickly and eliminate hysteresis.

Most pneumatic actuator designs simply cannot meet the operating and size restrictions, and hydraulic actuators, with all of their associated maintenance problems, are used instead.

A Kinetrol Distributor in the Southwest USA was asked to recommend a better alternative to a line where very large scotch-yoke actuators controlling two (2) 18" valves were controlling poorly and were taking up too much space.

The Distributor's challenge was to:
  • Deliver very high torque output.
  • Provide as small a package as possible.
  • Improve the actuators stability and reliability.
The solution was to apply Kinetrol model 30 vane actuators. The model 30's deliver 168,000 lbf (at 100 psi) of torque in a compact envelope (comparatively). Additionally, the Kinetrol Model 30's, combined with third-party digital valve positioners, provided the precision and response the application required to eliminate oscillations and instability.  The actuators cycle about 20 times per day and have been performing without problem for years. Huge annual fuel savings can be directly attributed to the actuators reliability and precision due to fewer turbine restarts.

Steam Balance Valve
Power plant steam balancing valves in service.

For more information, contact Kinetrol USA by visiting or by calling 972-447-9443.

Kinetrol Vane Actuators: Performance Under Pressure

Here is a short video of Kinetrol valve actuators installed in power plant, chemical plant, cement plant, water treatment, and primary metal plant applications.


Kinetrol Vane Actuator Outperforms Rack and Pinion on Power Plant Filter-Demineralizer System

Power Plant Filter-Demineralizer System
Kinetrol Vane Actuator on Power Plant
Filter-Demineralizer System
An important component of combined cycle power plant design and operation is condensate polishing, commonly referred to as "CP". CP is a process that purifies condensate. High purity condensate maximizes uptime in power plants by maintaining stable condensate chemistry and reducing corrosion transport. Power plants install specialized filter-demineralizer systems which remove both suspended solids and ionic contaminants to maintain optimal condensate  chemistry.

At one midwest power utility company, a valve controlling the flow of water (210 psi and 140 deg. F) that feeds the demineralizer was causing concern. The valve's accompanying rack and pinion actuator was creating a maintenance problem. While this isn't a high cycle application, the system must be 100% reliable, and the old actuator's performance was unreliable. The solution was to install a Kinetrol vane actuator. A new automated valve was installed 6 years ago (2012) and the Kinetrol actuator has operated flawlessly since then.

Power Plant Bearing Cooling Water Temperature Control

A midwest power plant was using a diaphragm control valve to control water temperature for their bearing cooling system. The closed-loop bearing cooling system uses the modulating valve to control water temperature between 50 and 170 degrees F. at 170 PSIG. The diaphragm valve was not able to provide the required signal response for tight control.

The local Kinetrol Distributor specified a high performance butterfly valve (HPBV) with Kinetrol spring return actuator and third-party positioner. The new valve and actuator package provided  reliable and accurate controllability with zero hysteresis. It has operated continually for 3 years without maintenance.

Bearing Cooling Water Temperature Control
Bearing Cooling Water Temperature Control Valve

Kinetrol Actuators on Power Plant Descaling Water System

Kinetrol on descale water system
Kinetrol actuator on
descale water system.
Overtime, heat exchanger tubes in power plant boilers build up mineral deposits that prevent proper heat transfer. The poorer the heat transfer, the higher the boiler tube exposure temperature. The higher the exposure temperature, the shorter the life of the boiler tubes. To remedy this, a chemical and mechanical process called descaling is used. Descaling removes these mineral deposits and restores proper heat transfer.

Kinetrol on descale water system
Wider view.
This Kinetrol actuator application is located on the descale water system at a power plant in the Midwestern United States.  Knifegate valves with pneumatic cylinder actuators were installed on the system and were failing. The knifegate valve packing material leaked and created a maintenance nightmare. The customer needed a longer term, lower maintenance solution.

The local Kinetrol Distributor recommended switching to a high performance butterfly valve (HPBV) and Kinetrol double acting actuator as the replacement. These actuators and valves are installed in a very dirty area (see picture), and during power generation, are exposed to high heat and are cycled every 30 seconds. The first installation has been in place for 20 months and operating without problem. Now, as each knifegate comes up for maintenance, they are being replaced with the Kinetrol operated butterfly valve.

For more information, contact Kinetrol USA by visiting or calling 972-447-9443.

Dampers and Louvers Used in Power Plants, Refineries, Boilers, and Furnaces

parallel damper
Parallel damper with electric actuator.
A damper (otherwise known as a louvre) is a multi-element flow control device generally used to throttle large flows of air at low pressure. Dampers find common application in furnace and boiler draft control, and in HVAC (Heating, Ventilation, and Air Conditioning) systems.

Radial damper
Radial damper.
Common damper designs include parallel and radial. Parallel-vane dampers resemble a Venetian blind, with multiple rectangular vanes synchronously rotated to throttle flow through a rectangular opening. A photograph of a parallel-vane damper is shown above, part of an induced-draft (suction) air fan system on a separator at a cement plant. The vanes are not visible in this photograph because they reside inside the metal air duct, but the electric actuator mechanism and linkages connecting seven vane shafts together are visible.
pneumatic vane actuator damper drive
Pneumatic vane actuator damper drive.

Radial-vane dampers use multiple vanes arranged like petals of a flower to throttle flow through a circular opening. A photograph of a radial-vane damper is shown here (note the levers and linkages on the periphery of the tube, synchronizing the motions of the eight vanes so they rotate at the same angle).

Dampers are opened and closed by electric or pneumatic drives. In recent years, the pneumatic vane actuator  has earned an reputation for modulating dampers. Used in critical applications commonly found in power plants, refineries, boilers, and furnaces, these unique damper drives provide precise combustion gas management, are proven to increase boiler efficiency, lower fuel consumption, reduce emissions, and reduce maintenance cost.

Parts of this post are reprinted from Lessons In Industrial Instrumentation by Tony R. Kuphaldt – under the terms and conditions of the Creative Commons Attribution 4.0 International Public License.

Valve Actuators for Bottom Ash High Pressure Spray Removal

coal burning power plant
Coal burning power plant
The pulverized coal boiler is the most common type of coal-burning furnace in the electric utility industry. After the pulverized coal is burned in a dry, bottom boiler, approximately 80 % of the unburned material or ash gets captured and recovered as fly ash. The remaining 20% of ash is categorized as bottom ash, a dark gray, granular, porous ash that is collected in a water-filled hopper at the bottom of the furnace. When a sufficient amount of bottom ash is collected in the hopper, it is purged by high pressure water jets into sluiceways or other conveyances for further processing.

Kinetrol Actuator
Kinetrol Rotary Vane Actuator
The high pressure water (approx. 400 PSI) is actually recycled ash water and is very abrasive. The valves and control systems used to move the bottom ash slurry are typically 3” to 12” double offset, high-performance butterfly valves. Double acting pneumatic actuators are most common for opening and closing. Cycle frequency varies, but most typically are between 3 to 12 times per day.

Its crucial that the double offset valves seat completely and are truly “zero-leakage”. In this high pressure and high abrasion scenario, even the slightest leak will cause a rapid failure of the valve seat.

Rack and pinion, scotch yoke, and electric actuators are problematic because of the inherent hysteresis in their gearing. This hysteresis compounds over time adding to the amount of error introduced and increasing the likelihood of a poorly closed valve.

Rotary vane actuators, on the other hand, provide “hysteresis-free” seating due to their single moving part and one piece vane and shaft design. When mounted to the butterfly valves with a no-play coupler, the valve disc is guaranteed to close tightly, without degradation over time.

Additional benefits of using the vane actuator is smooth, controlled closing to reduce the possibility of water hammer and the greater ability work in poor quality atmospheres, both of which are considerations for this application.

The Virtues of the Pneumatic Vane Actuator Damper Drive

pneumatic damper drives
Pneumatic damper drives
Pneumatic damper drives significantly improve the reliability, precision, and efficiency of industrial boilers and furnaces. Accurate control of combustion air and flue gas provide many cost savings benefits to plant operators. A pneumatic damper drive’s precision and rapid response greatly improve fuel efficiency, reduce emissions, lower fuel consumption, and provide better boiler draft control.

Recent “Boiler MACT” (Boiler Maximum Achievable Control Technology) regulations require regular maintenance to optimize boiler performance. Air-to-fuel mixing and CO emissions are two areas where fine tuning and precise control yields dramatic improvement in burn efficiency. Old electric drives do not provide the precision, speed or torque needed for accurate control, so a retrofitting program that replaces electric drives with pneumatic units is an easy way to improve efficiency and gain better performance.

In the application outlined below, several dual-arm damper drives, using Kinetrol Model 18 actuators, were specified to replace aging Bailey electric damper drives in a power plant in the southwest USA. These specific drives are used to control the desuperheater and reheater temperature at a gas fired plant. Not only was there a need for optimized performance for better fuel consumption and lower emissions, but the customer was also very concerned about reliability. The plant needed to know the new Kinetrol-based damper drives were immediately available, and ready for drop-in replacement as the Bailey drives failed. This was easily managed by designing pedestals and frames that matched the bolting patterns and envelope size of the existing Bailey units. The Kinetrol drives were designed to match the legacy footprint exactly, have the drive shaft and drive lever in the exact position, and provide a drive shaft and lever with the same dimensions as the Bailey drive.

The result is a high duty cycle, highly precise, long-life, fast acting, responsive, easily maintained, and easily automated damper drive.

Very High Cycle, Coal Power Plant Butterfly Valve Application

vane actuator
One moving part. Simply the best.

A coal fired power plant was using old Powell gate valves with dual air cylinders and volume tanks. Because of high cycle rate (the valve cycles open/closed every 30 seconds), the Powell gate valves were breaking down constantly - leaking at first, then failing. Downtime for repair was costing a fortune.
Kinetrol Model 12
Kinetrol Model 12

A local Kinetrol Distributor was called in to recommend a better solution. After discussing the capabilities of Kinetrol, the power plant decided to replace the gate valves with 6" high performance butterfly valves actuated with Kinetrol size 12 actuators, spring returns and limit switch packages. 

The result was a robust valve/actuator package that could handle the 120 cycles per hour required - truly a difficult application. As of two years in operation, both valve and actuator have been running reliably much to the delight of the power plant maintenance crew. 

High cycle coal fired power plant Kinetrol / HPBV application.