NOVELTY - Steam or water are dosed into the gasification chamber (2) after gasification starts. The quantity is controlled as a function of the free-space temperature in the gasification volume. This temperature is kept at 280-650 degrees C, or the temperature in the bales (1) is kept at 450-800 degrees C. Only small quantities of ash are melted and only small quantities of fine dust are formed. The ratio of biomass charge volume to the heat introduction rate into the chamber, is 0.005 m3 per kW. This keeps the gasification rate low. The fuel gas produced is burned directly without cooling, in a combustion chamber (6), at above 750 degrees C.    USE - A process minimizing fine dust suspension during thermal gasification of biomass in stem- or lump form.    ADVANTAGE - The plant described and a simple operating process, minimize dust suspension in the product fuel gas. Environmentally-unacceptable liquors produced in the scrubber are returned to the gasification chamber. No other elaborate processing of this contaminated water is required. No costly disposal is required. Such gas scrubbers can be included in even small gasification plants.    DETAILED DESCRIPTION - The biomass is in the form of bales, bundles, stacks or pellets. Part of the feedstock is burned for heating. The burned gases are fed through a heat exchanger. In a variant design, the fuel gas is quenched in a chamber, to cause slag- and dust precipitation. Contaminated water from the quench chamber is introduced into the gasification chamber for temperature control as described. The water evaporates. This leaves a large proportion of slag and dust from the gas, captive in the biomass charge. The portion entrained-out with the fuel gas, is burned-off directly without intermediate cooling. Total water introduction into the gasification chamber, for whole bales of stems, is preferably about 20 wt%, based on the total weight of bales. Water sprayed into the quench chamber collects below, and is dosed into the gasification chamber. Water or steam dosed is uniformly distributed, away from the gas offtake opening (5). Water is sprayed into the combustion air supply duct. It is dripped or sprayed above the biomass in the gasification chamber. Water introduction is increased linearly at chamber gas temperatures exceeding 400 degrees C, to avoid exceeding 650 degrees C in the gas space. Gas is locally concentrated and accelerated in the gasification chamber, to remove slag and ash. The chamber gas temperature is measured. The normal rate of blowing per kg is increased at temperatures below 400 degrees C in order to minimize water introduction. Further plant details are supplied. An INDEPENDENT CLAIM is included for corresponding biomass gasification equipment.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross section of the biomass gasification unit.    bales (1)    gasification chamber (2)    grate (4)    fuel gas outlet opening (5)    combustion chamber (6)    ash chamber (7)    air supply opening (8)    water injector (9)