Reliable Technology – Continuously Improved and Optimized
Grate combustion is the best-proven thermal waste treatment technology. HZI has continuously optimized, developed and adjusted it to changing statutory conditions and requirements. Today, grate combustion is the most advanced technology with regard to environmental friendliness, operating reliability, flexibility and cost-effectiveness.
Grate Combustion System
The grate combustion technology developed in-house is specially designed for the thermal treatment of municipal solid waste. It has been perfected through decades of operating experience and today achieves unsurpassed levels of efficiency and reliability.
Its core is an inclined reciprocating grate and it consists of the following elements.
- Waste feeding system
- Air-cooled or water-cooled Grate – Aquaroll®
- Combustion air system
- Flue Gas Recirculation system
- Advanced Combustion Control System
- Bottom ash handling system
Well-Proven and Reliable Combustion Technology
The rugged construction of the grate and its insensitivity to highly heterogeneous waste fractions explain why grate combustion remains the most wide-spread method for thermal treatment of residual waste today. In fact, it constitutes the heart of Energy-from-Waste plants and is the technology of choice not only for untreated municipal and industrial wastes, but also for refuse-derived fuels and for pre-treated wastes.
Conveying and Stoking to Perfection
From the feed hopper and chute the ram feeder doses the waste onto the grate in a controlled way. The grate is composed of individual grate modules with alternating fixed and moving grate block rows. The hydraulically-driven moving grate blocks stoke the waste and convey it through the combustion chamber as needed to achieve optimum burn-out.
The number of grate modules depends on the specific throughput, the properties and the calorific heating value of the waste. Various grate modules are assembled in rows and lines to suit each specific situation with a capacity between 4 to about 44 tons per hour.
The air-cooled grate with its robust design has proven to be very reliable. Depending on the properties of the waste, it is the most favorable solution in terms of capital and maintenance costs.
For high thermal loads, especially those containing conditioned waste with higher calorific values, water-cooled grate bars ensure optimum burnout and increased lifetime. They offer a decisive advantage: in every zone, the airflow can be adjusted precisely to combustion requirements and if necessary even reduced to zero.
Fluidised Bed Combustion System
Improved Cost-Effectiveness Thanks to Optimized Design and Improved Materials
The Inova fluid bed has many advantages compared to the multiple hearth:
- Uniform bed temperature and high bed turbulence result in low excess air requirements and low formation of pollutants.
- Optimized fluidization, distribution, and residence time allow for efficient gas burnout.
- Single refractory line vessels with no moving parts reduce maintenance and outage durations.
The design of the fluidised bed combustion has been successfully demonstrated in many different industries, which includes but is not limited to the following:
- Municipal or industrial sewage sludges
- Paper mill spent liquors or waste sludges
- Petrochemical waste sludges
Shock Pulse Generators
Clean Boilers for Safe, Economical and Ecological Operation of Power Plants
The Shock Pulse technology was developed by Explosion Power GmbH. The generators are used for cleaning boilers in waste treatment and biomass plants, for example, where they introduce pressure waves into the boiler at regular intervals, thus removing ash and particle deposits from the boiler pipes.
The efficiency of continuous boiler cleaning systems is therefore of very high importance to the plant operation, in order to avoid deposit build up efficiently from beginning of boiler operation.
The goals of online boiler cleaning systems are:
- High cleaning efficiency
- Reliable and safe automated operation
- Low operating cost
- No damaging of heating surfaces
- Small space requirement, small building volume
- Applicable for new plants as well as for retrofits
- Broad application range for various fuels and different boiler types