The utility model provides a grate type
combustion furnace which comprises a furnace body, a cavity is arranged in the furnace body, an ignition mechanism is arranged in the cavity, an air supply port, a fuel feeding port and a high-temperature
smoke outlet are arranged on the furnace body, and the grate type
combustion furnace is characterized in that a plurality of
layers of grate plates which are sequentially overlapped in a staggered mode are arranged in the cavity of the furnace body from top to bottom, and the high-position ends of the plurality of
layers of grate plates are connected with the fuel feeding port. The rest of the grid plates extend towards the high-temperature
flue gas outlet, the heights of the grid plates are reduced layer by layer, a plurality of air holes are formed in the grid plates, the multiple
layers of grid plates are connected with a translation driving mechanism, and the air holes are connected with external air supply equipment through an air supply mechanism. The horizontal moving driving mechanism drives the multiple layers of grid plates to stretch and retract forwards and backwards, so that fuel on the multiple layers of grid plates can continuously move from the fuel feeding port to the high-temperature
flue gas outlet and is evenly laid on each layer of grid plates. Hot air supplied by external air supply equipment can be introduced into the cavity through the air holes, so that fuel continuously floats in the furnace body, and the effects of uniform preheating and uniform
combustion are achieved. The quick separation of volatile components in the
biomass fuel is improved, the combustion efficiency of the fuel can be improved, and the generation and emission of harmful substances are reduced.