Woodchips: 60 – 1500kW
A woodchip plant consists of a scraper unit which is logically located in the immediate vicinity of the woodchip plant. 3 horizontal scrapers are positioned in the magazine which feed fuel to a countersunk lateral worm drive at the end of the scraper system. The worm drive is monitored by a photocell and when the drive is full, the hydraulic cylinders will activate the scraper unit, and stop again once the worm drive is full. The woodchips pass from here on an inclined worm drive directly to a cell sluice to be fed via another worm drive into the combustion hearth or a step grill. Whether to use a hearth or grill will depend on the condition of the chips, particularly with regard to water content.
HEB columns are cast in-situ at the end of the scraper unit on which we build a plank wall over the lateral worm drive, and the drive itself along with the hydraulic cylinder mounts are also cast in-situ.
The ‘on-demand’ function of the boiler will activate the feed procedure, i.e. the scraper unit and worm drive will start The scraper unit will now supply the boiler with the appropriate amount of woodchips for the boiler capacity. Chip volume is controlled by an oxygen gauge which constantly monitors oxygen percentage in the flue gas.
LIN-KA H boiler
The hot water boiler is a cylindrical, efficient, 3-phase pipe boiler designed for burning straw. It features a smooth flame channel, water-cooled rotation chambers and is dimensioned to achieve full combustion and efficient utilisation of radiated heat in the flame channel, whilst convection heat is utilised to the maximum in the two subsequent flue gas sections.
At the end of the boiler combustion chamber is a cylindrical water- and air-cooled combustion hearth, which helps avoid slag formation. Preheated air is added from the sides and top to create the correct amount of turbulence in the combustion area, and completely burning off the gases developed.
Thorough insulation of the boiler with 100mm mineral wool means that heat loss is minimal. The boiler is a fully welded, gastight and sealed unit, supplied with nozzles, flanges and counter-flanges for feed and return, plus safety nozzles. A cleaning hatch at the end of the combustion chamber makes inspection and cleaning simple.
The boiler is available in sizes ranging from 60-1500kW for straw, with the standard version designed for a max. operating pressure of 4 bar, and max. operating temperature of 110º C. An elegant exterior of blue plastic-covered steel panels gives the LIN-KA H boiler an attractive, modern design.
Automatic ash extraction
A stainless steel, laterally-mounted worm drive is fitted in the base of the boiler to transport ash out to the inclined worm drive, which takes it onwards, including outside the building, to an ash container.
Automatic flue cleaning
A number of pressure tanks are mounted on the boiler with air injection valves fitted to inject air into the boiler flue to keep it clean. This means that manual cleaning of the flue is rarely necessary.
Electronic control and monitoring system
Control and monitoring of the woodchip plant is based on a PLC control system (Programmable Logic Controller). This ensures controlled regulation of fuel feed to maintain maximum heat production. All set points can be read off and reprogrammed via a display and the oxygen percentage is continuously shown on the display. There is also an alarm outlet on the control system.
The control panel can be connected to the internet if the boiler room has a fixed IP address to facilitate remote support from LIN-KA when commissioning, trimming and in the event of disruption to production.