Patent ID: 7621972

Claim:
A method for loosening deposited slag in a reactor for pressure gasification of fuels, said fuels including coals of various ranks, cokes, or ash- containing liquids or liquid-solid suspensions, at pressures between ambient pressure and 80 bar, at gasification temperatures ranging between 800 and 1800° C., in an arrangement comprising a quench chamber mounted downstream of a gasification chamber and a slag lock hopper disposed thereafter, a valve connecting the quench chamber and slag lock hopper, and a water bath in a lower part of the quench chamber, the method comprising the following steps: supplying quench water at a level above the water bath for cooling down the crude gas and slag from the gasification chamber; and maintaining a water circuit between the quench chamber, the valve, the slag lock hopper and a pump, said circuit water being circulated above and below a level of the water bath and said valve being in an open position, wherein said circuit water is supplied through circuit lines separate from the quench water input, wherein the circuit water is pumped backward and forward in the circuit lines between the quench chamber and the slag lock hopper, the quench chamber and the water bath, and the slag lock hopper and the water bath.