Hydraulic grate firing plant

Nominal power of the boiler:  from 300 kW to 20.000 kW

The hydraulic grate firing plants are suitable for following fuel-types:

Fuel division hydraulic grate firing plants

System of firewood feeding and loading

Fuel can be discharged from

- square and rectangular hoppers (tip down bunker).

The reciprocating grate combustion system

Hydraulic reciprocating grate especially was developed for wet and dirty biogenous fuels
of low calorific value.

Depending on the kind of fuel and local conditions material is fed to the furnace by means of
worm conveyors or hydraulic feed systems.

The grate-steps moved separately and water-cooled hydraulic staircase grate
enable an optimal combustion or combustion process particularly with dry and especially
wet material.

By  the full automatic embers bed regulation fuel is always spread over water cooled grate.
So optimal effect will be obtained due to the special geometry of fireroom.

View into a fireroom of a hydraulic reciprocating plant.

The grate is divided into three combustion areas drying partially combustion material in the first zone. Supported by the geometry of fireroom the degassing of fuel takes place. In the third and last zone fuel fed is completely combusted (burn out and ash removal).

Several frequency controlled fans feeding combustion air especially coordinated for the
respective zones enable complete combustion mixing combustion air with oxygen. Necessary
quantity in different combustion-zones is calculated by the control (output power control system).

Fans feeding combustion air

As a sign for permanent innovative research a calorifier of the initial heating of
fuel and drying was installed for further improvement of efficiency run with unused
heat of exhaust gases.

At the end of the grate the ash that arises at combustion will be transported to an
ash-container via dropping or transported into a standard container via automatic
ash removal systems. The ash that falls through due to the movements of the grates
will automatically be removed out of the zones below.

The combustion-gases are burned completely due to stepped combustion and permanent control of the remaining value of oxygen and conducted into the heat exchanger situated
there.

Heat exchanger

Transmission of energy of hot waste gases into the system for use of heat is carried out
with the heat exchanger, which shows utmost comfort for operating  at cleaning and
maintenance.

Automatic pressure air cleaning unit for boiler tubes

The following media for heat carrier can be used for it:

• warm water up to 95ºC
• hot water up to 120ºC
• hot water more than 120ºC
• thermo oil up to 300ºC
• low pressure steam up to 1 bar
• steam up to 36 bar
• hot steam up to 450ºC

Flue gas dedusting

In principle flue gas dedusting is carried out by an attached multi-cyclone for trapping
of flying ash. A lower residual content of dust is required by legislation for bigger plants.
For keeping this level there will be used systems like

• electrostatic filter
• tissue filter
• condensation plant

multi-cyclone	ectrostatic filter

For holding up the degree of effectiveness in each point of operation a part of flue gas
is resupplied to the heating through flue gas recycling.

The rest of the cleaned waste gases is conducted through exhaust gas fans to chimney
plant.

Computer-controlled regulation

Full-automatic control and regulation of the complete firing plant on biomass is
carried out from a SPS (programmable memory-control).

Influence of oxygen, furnace temperature, flue gas recycling, flue gas temperature,
temperature of combustion air, quantity of material, humidity of material, flow pipe
and return pipe temperature and consumption of individual consumers (net) can be
projected in full-automatical control and regulation of SPS and further processed
into instruction signals by an integrated oxygen and capacity regulation.

Heating operation works full automatically, from supplying of biomass, control
and regulation of combustion up to control of the pumps.

On request all these parameters can be processed with a process-visualisation and
saved in single figures or comprehensive diagrams and statistics.

The components of the plant recorded schematic and saved thus enabling us to have a summary of the status and the functions of single parts of the plant and of the complete
plant in a simple and clear manner. Each little difference to the predefined parameters are
displayed and automatically led back into the set condition.

Because of this kind of visualisation it is not only possible recording on the monitor
or memory but also with a PC and a modem it is possible to see a change and differences
in the set point of all parameters anytime.