Showing posts with label electrostatic precipitator. Show all posts
Showing posts with label electrostatic precipitator. Show all posts

Tuesday, July 25, 2017

Electric Process Heaters & Controls

Hotfoil specializes in electric surface heating systems for fly ash hoppers on electrostatic precipitators or baghouses, coal and material handling systems, tanks, pipes, etc. in all types of industry.

For more information, visit http://www.hotfoilehs.com or call 609.588.0900.

Thursday, March 30, 2017

Electric Heating and Control Solutions for Power Generation

Hotfoil-EHS specializes in electric surface heating systems in power plants for fly ash hoppers on electrostatic precipitators or baghouses, coal and material handling systems, tanks, and pipes.

For more information, visit http://www.hotfoilehs.com.

Monday, February 27, 2017

Eliminate Costly Hopper Pluggage with Electric Hopper Heaters

hopper heaters
Modular, metal-clad hopper heaters
installed on large hopper.
Fly ash is a by-product of coal fired and waste-to-energy fired electrical generating facilities. Fly ash is a combination of dust and fine particles produced during combustion. Environmental laws require fly ash to be collected and not released in to the atmosphere. Large collectors called electrostatic precipitators combined with a system of filters extract fly ash from the flue gas and dispense the fly ash in large steel hoppers prior to being dumped in to containers and transported.

Due to the temperature differential between the hot internal temperature of the hopper and the cooler exterior, condensation forms on the internal wall surfaces, The condensation, combined with the fly ash, creates a concrete-like material that bonds to the hopper walls. The accumulation of this material eventually clogs the hopper to the extent it cannot be emptied. At this point, the only way to free the clogged material is with sledge hammers and pneumatic tools and long periods of downtime and the related expense.

To prevent the fly ash and condensate mixture from forming,
electric heaters are bonded or clamped to the exterior walls and throat of the hopper. Because the environment is normally very dirty with high vibration, “hopper heaters” are designed to withstand to meet these mechanical and environmental stresses.


Hopper heaters come in a variety of physical sizes, voltages, and wattages. Most often, hopper heaters come in pre-engineered sets that have been specified and configured by an applications engineer.

For more information on any hopper heating application, contact Hotfoil-EHS for a free consultation. Visit http://www.hotfoilehs.com or call 609.588.0900.

Sunday, February 28, 2016

Electrostatic Precipitator and Bag House Hopper Heaters Prevent Fly Ash Production Problems

hopper heaters for power plants
Coal fired power plants must manage fly ash properly.
Coal fired power plants in the United States require the use of electrostatic precipitators or bag houses to filter out very fine fly ash particulate incorporated in the flue gas. The ash is collected as the flue gas passes through filter bags or by large electrodes, and then falls into collection hoppers.

As the hot fly ash cools, condensate on the hopper walls can form. The mixture of dry, sulfur rich fly ash and water is very problematic, so it's very important to keep condensation from forming in the collection hoppers. The mixture of water and fly ash can cause clogging (or “pluggage”) in the throat of the hopper,  and more importantly, the residual sulphur in the flue gas will combine with the condensate to form sulphuric acid. The suluric acid attacks the hopper walls from the inside causing corrosion, weakening the walls and creating significant (and costly) maintenance issues over time.

hopper heaters for power plants
Fly ash hopper with heaters.
Efficient and continuous fly ash removal is critical for all coal fired power plants. Collection hoppers are an integral part of the removal process. Pluggage or inoperable hoppers are a known issue to engineers and maintenance crews. The constant maintenance and excess of down time seriously hinder a plant’s ability to manage the fly ash production rate. Slower fly ash production means limiting energy production and efficiency. A power plant’s electricity production is directly proportional with its coal combustion rate which, in turn, directly effects the fly ash production rate. Plant maintenance personnel usually attempt to remedy ash system failures in real time by deactivating the affected hopper while continuing to generate power and ash. In some situations (to prevent boilers shutdowns) ash will be dumped on the floor, requiring costly clean up.

The evacuation and management of fly ash is much easier when the ash is kept hot. One of the most common ways to maintain elevated fly ash and hopper temperature are electric hopper heaters attached to the external hopper walls. Hopper heaters play a very important role in the removal of fly ash from precipitators and bag filter hoppers by keeping the hopper temperatures operating above the flue gas acid dew point. The hopper heater’s sole function is to preheat the hopper and the internal environment to prevent the formation of moisture and the resulting clumping of fly ash and development of sulphuric acid.

hopper heaters for power plants
Flexible heating element used on hopper throat.
Hopper heaters are designed for the dirty, high vibration environment of a power plant. They provide the optimum watt density for proper conduction through the hopper wall and for uniform heating. The are available in square, rectangular, and trapezoidal shapes to accommodate any hopper design. Ancillary flexible heating blankets are available for poke tubes, man-ways, and cylindrical throats.

The use of electric hopper heaters on electrostatic precipitator and bag house fly ash collection systems is a time proven, effective way to prevent condensate formation and the resulting clumping and corrosive acids in hoppers, thus facilitating a better opportunity for uninterrupted fly ash production.

For more information, contact:

Hotfoil-EHS, Inc.
2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333
Email: dap@hotfoilehs.com
www.hotfoilehs.com