NOVELTY - A gasification system includes a solid fuel feeding unit (1), a solid fuel gasifier, an ash extraction system (2.15), and a gas cleaning unit (3).    USE - System for gasification of solid fuels such as coal, lignite, petro coke, dangerous solid wastes, domestic solid waste, industrial solid waste, biomass covering wood charcoal, wood wool, wood shaving, agricultural wastes, treatment sludge, leather wastes, leather industry treatment sludge and cleaning of the produced gas.    ADVANTAGE - The system prevents occurrence of supply or feeding problems; prevents problems such as overflowing; provides low tar production and convenient synthetic gas mixture; has highest efficiency in power and heat economy; prevents occurrence of gas leakage into external environment, and provides safety at maximum level; prevents blocking because of properties of the raw materials; prevents ash and soot clogging in the gas output pipes; prevents occurrence of agglomeration, sintering, and clinkering problems in the ash; prevents pressure loss, gas leakage and air leakage in the solid fuel gasifier as the ash is flowed into water in the ash emission system; provides production of combustible gas of carbon and hydrogen content in the most economical and easy way; provides optimum level of gasification of solid wastes particularly enriched and converted into briquette and pellet; provides cleaning of harmful gases, all tar derivatives such as dust, ash, heavy metal, metal oxides, hydrogen sulfide, hydrogen cyanide, ammoniac existing in the gas generated in the solid fuel gasifier and thus ensure operation of gas cleaning line and system free of problem; provides heat insulation and metal material wearing in solid fuel gasification zone; and is environment-friendly.    DETAILED DESCRIPTION - A gasification system comprises:    (A) a solid fuel feeding unit (1) feeding briquette or pellet solid fuels into the system;    (B) a solid fuel gasifier comprising a drying zone (2.1) providing vaporization of the water content of the solid fuel pellet or briquette, a pyrolysis zone located on the lower part of the drying zone, where solid fuels are subjected to thermal deformation at 400-600 degrees C and decomposed into coke, char, tar, carbon monoxide (CO), methane (CH4), and hydrogen (H2), an oxidization zone and a reduction zone located on lower part of the pyrolysis zone, where oxidization and reduction reactions are realized at 1000-1200 degrees C with heated air and organic compounds and char compounds having all high molecule weight of the pyrolyzed solid waste are oxidized and reduced and decomposed into CO, H2, carbon dioxide (CO2), CH4 and light hydrocarbon of very light molecule weight, a strait zone located on the lower part of the reduction zone where the obtained solid fuel gas and ash are conveyed, a screen zone located on lower part of the strait zone, a second oxidization zone where the screen part combines with partial air once more and the remaining char is oxidized;    (C) an ash extraction system (2.15) located on the lower part of the solid fuel gasifier, an extraction and mixing apparatus preventing agglomeration and sintering that might occur in the ash during gasification and wet discharge system (2.7) into which the produced ash is discharged; and    (D) a gas cleaning unit (3) comprising dust separator cyclones providing cleaning of impurities such as dust, soot, ash grains, tar derivatives, hydrogen sulfide (H2S), hydrogen cyanide (HCN), dioxan, furan and water, and trapping dust particulates existing in raw gas leaving the solid fuel gasifier, wet gas flusher where heavy char in raw basis in the gas, soluble char and chemical agents such as H2S, HCN are passed through flushing solution and cleaned, wet solvent pool located on the lower part of the wet gas flusher, where collected char and dust particulates are accumulated in form of soil upon agglomeration, oily gas flusher where light char derivatives, char derivatives in form of aromatic and aliphatic structure not soluble in water, benzene, toluene, and o-, m-, and p-xylene (BTX) aromatic compounds are passed through grease to be cleaned, flushing oil tank located on lower part of the oil gas flusher where the accumulated tar are accumulated, sand filters used to recycle water solvents and oil solvents used in wet gas flusher and oil gas flusher, wet electrostatic precipitator where liquids, dust particulates, heavy metal particulates, acid fogs, smokes, dioxan or furan compounds of aerosol in micron size are electric loaded and providing holding in the water saturated gas, a gas emission fan providing gas emission from the system and pressure decrease, gas storing tank providing supply of produced cleaned gas into gas burning line without floating in gas supply and procuring the required gas amount in case of various stops, gas conditioner which filters the dust particulates remaining in synthetic gas produced and cleaned in solid fuel gasifier and provides required moisture to the gas, gas cooling/heating part where the temperature adjustments and moisture adjustments of the gas from gas conditioner are provided.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the solid fuel gasifier and gas cleaning system.    Solid fuel feeding unit (1)    Drying zone (2.1)    Ash extraction system (2.15)    Wet discharge system (2.7)    Gas cleaning unit (3)