Chutes
As part of the overall feed hopper system, the use of water-cooled feed chutes is a widely used system in thermal waste recycling plants, with heat arising from possible backfiring being dissipated over the water-cooled outer walls. However, experience has shown that the cooling systems usually employed, are incapable of meeting all of the requirements. In the event of backfiring, steam bubbles can form, which lead to local thermal overheating and deformation of the inner and outer walls. Moreover, the increased demands of corrosion and abrasion prevention are not always met.
- Thermal loads due to backfiring
Backfiring frequently generates very high local thermal loads which can lead to deformation. Poor cooling also harbours the risk of damage due to steam formation and steam hammering in the cooling system. Cooling systems without forced circulation are at risk here. The flow of cooling water may be hindered if steam bubbles form in these systems, and this may cause material overheating and damage. - Corrosion
Corrosion can be particularly severe in cooling systems with poor circulation, especially if oxygen enters the system. - Biological contamination of cooling water
Cooling water in open cooling systems can lead to the formation of bacteria which pose a health risk on contact. Biocides prevent this development, but they can only be used in closed systems.
The EnergieLink solution
Chute with closed and active cooling circuit
The mechanism and process in the cooling circuit design ensure that steam bubbles forming during backfiring are safely conveyed out of the feed chute, thus ensuring that no overheating occurs. Cooling water flows through each individual segment, with the flow rate in each segment and the temperature at the cooling water outlet being measured. This means that the heat source can be located early in the event of possible backfiring, an alarm can be triggered, and countermeasures initiated. Serious backfires are now very rarely encountered, thanks to this early detection. However, if this does occur, replenishment of cold cooling water is triggered. The heat is distributed via the cooling system in most cases, which is adequate in the case of minor backfires. The feed chute is also protected against overheating by an efficient water-cooling system.
Coating with composite materials resistant to abrasion and corrosion
Wear-resistant materials are employed wherever necessary when selecting materials. For example, surfaces facing the waste are made of composite materials resistant to abrasion and corrosion. These can be selected in specific thicknesses up to 5 mm.
Ease of handling due to segmental construction with plates screwed to one another
Individual water-cooled segments in the upper and lower area can be easily replaced. In terms of size, they are selected so that they can be integrated segment by segment in the plant.
Advantages of the EnergieLink chute at a glance:
- Segmental construction
- Corrosion and wear-resistant materials
- Closed cooling circuit with constant flow
- Dosage of corrosion inhibitors and biocides possible
- In the case of small backfires, the heat is dissipated, for example via the pipes, eliminating the need for additional cooling.
- Additional safety through automatic water replenishment in the event of a further rise in temperature or unexpectedly serious backfires
- Consistent flow and monitoring of each segment
- Flow measurements and balancing valves ensure a uniform flow through each segment that can be checked locally
- Temperature monitoring per segment, guaranteed early indication and location of a backfire enable timely initiation of countermeasures
- Rapid reduction of temperature peaks
- We also offer the option of different fire extinguishing systems