Ash removal systems

Furnace waste handling system is an important element of a boiler island. Ash removal system is a set of devices and installations which collect ash in ash precipitation spots and its removal to a waste dump or to storage vessels. 

Ash is removed from under the combustion chamber, second boiler stack, furnace bridge, electro filters and from under chimneys. Depending on the form, granulation and release spot, one may differentiate from: slag, fly-ash and fine ash. Ash removal in power plants uses the following types of ash removing systems: mechanical, hydraulic and pneumatic, and their combinations. The choice of ash removal system depends on ash quantity, quality, its features, distance from the dump, water conditions, and requirements set by as collectors. Physical and chemical characteristics of ash may differ depending on its chemical composition. Some ash components when in contact with water may lead to cementation (CaO) or its swelling ( Al2O3).

We offer ash removal systems and wet slag handling systems customised to a given boiler type, investor's requirements and quality of fuel used. 

We offer proven constructional solutions for our devices. They ensure high operation in specific exploitation conditions present in those installations. 

Innovative solutions implemented in ash removal systems, and used materials and products of world-known manufacturers ensure failure-free operation of our systems in constant operation of power units.

We manufacture wet deslagging systems composed of:
- slug funnel located between funnel outflow of the boiler combustion chamber and slug chain trap,
- slug chain trap made of elements and systems resistant to difficult operation conditions,
- crusher,
- belt conveyor systems, chain conveyor or bucket conveyor that takes out slag to waste storage or silos.

Diagram of ash removal system

We provide complete systems for ash cooling and removal from furnace and transport to storage vessel for power units with fluidized bed combustion. In such boilers dry ash removal systems are used and they are equipped with a sifter and a crusher. 

Dry ash removal system is a high-tech solution nowadays replacing traditional method of hydro-ash-removal. It has many advantages which make more and more power consortiums decide to implement it in their plants. This method limits the need to use water in the process of ash cooling and handling (water is not dirtied), it makes it possible to reduce CO2 emissions and significantly reduces system production and maintenance costs. These systems are slowly becoming standard in countries like Germany or the Netherlands, however they are not so much common in Poland yet. 

Environment protection has lately became the main aim for many power plants in the world. Nowadays all efforts are focused on emission reduction (CO2, NOx, SOx, ashes, etc.) and to enhance ash, which had been treated as wastes several years ago. 

Moreover, international standards, which regulate the use of ash as component of cement or concrete, has changed lately. Ash is not wastes anymore, but may be used as a by-product provided that limits established in relevant standards are met. 

Ash removal systems developed by Prefamet Zremb S.A. are composed of high quality devices manufactured by Prefamet:

- worm conveyor / feeder 
- scraper conveyor / feeder 
- gathering conveyor / feeder 
- drag conveyor / feeder 
- screw conveyor / feeder 
- strand conveyor / feeder 
- bucket elevator / feeder 
- transporter
- ash cooler 
- aeration tube