Ash Handling Systems & Silos

Fly ash is one kind of waste produced by coal-fired power plants. Pollution control equipment used in coal combustion captures fly ash from the chimneys of coal plants. Fly ash and bottom ash that are removed from the base of coal furnaces are often referred to simply as bottom ash. Richmond Engineering Works has designed, supplied, and commissioned control systems that uniquely deploy dependable and easy-to-operate HMI systems.

These HMI systems and upgrades allow plant personnel to better monitor and more accurately control the system operation as well as help the maintenance personnel locate, diagnose and correct problems quickly and efficiently.


Upgrades and Features may include:


  • Upgrade United Conveyor™ or Allen Sherman-Hoff™ relay based controls and sequencers with new PLC based controls.
    • Benefit:
    • By upgrading to a PLC based control system, you will be eliminating a system that is quickly becoming obsolete. In addition, you will be making your ash system more reliable and more flexible. Lastly, a PLC control system is a less expensive alternative than replacing the drum, stepper or sequencer switches.
  • HMI systems allow the operator to better monitor and control the system.
    • Benefit:
    • With a central location, the operator is able to watch the system operations such as sequencing and ash feeding without having to physically walk down the system. Please note: we highly recommend walking down the system as a standard practice. However, with the PLC controls, the operation can be better monitored and trouble-shooting a problem can be done more efficiently. Also, data logging and fault monitoring can be done automatically.
  • Eliminate paper chart recorders of conveying pressure or vacuum and go to an electronic recorder or use the system HMI to monitor these critical signals.
    • Benefit:
    • Time and money can be realized by not having to change out daily the paper for the chart recorders. The recording can be done by the HMI and the HMI can give you a longer data or fault history than the paper charts.
  • New gearboxes for blower motors to eliminate belt drives.
    • Benefit:
    • By eliminating the belt, you are doing away with the belt which is a component that is prone to failure and you are also extending the life of the system bearings.
  • Fly ash feeder level and pressure instrumentation with monitoring/alarming. This instrumentation and alarms will indicate a fail to fill, fail to empty, fail to pressurize, or fail to vent condition and will help maintenance personnel to keep up with Nuva Feeders™ and maintenance. The same controls can also be used to measure how much ash is collected from each feeder.
    • Benefit:
    • This will help to prevent ash build up in hoppers and prevent curtain damage in the precipitator. Opacity spikes can be avoided if the ash system feeds properly.
  • New transmitters on vacuum and pressure lines.
    • Benefit:
    • With modern transmitters and controls, ash handling systems can be better monitored and controlled for switching between feeders and checking for vacuum or pressure leaks in the system.
  • PLC control systems:
    • Benefit:
    • In addition to replacing obsolete equipment and making the system more reliable, you are able to increase the flexibility of the system. You would now be able to switch from running the ash handling controls in batch mode to operating in continuous mode. By running continuously, this will help to eliminate plugged feeders and having the operators ‘rod-out’ the feeders.
  • Radio communications systems or fiber optic communications between fly ash system and fly ash silos.
    • Benefit:
    • With radio or fiber optic communication, you eliminate the trouble-some DC signal wiring. The radio or fiber optic communication will enable you to transmit more and detailed system information such as low differential pressure (due to a torn bag), exhaust fan failure and damper failure.