GB2108005A - Removing ash from a hot fuel product gas - Google Patents

Abstract

A method of preventing caking, consisting of liquid and/or glutinous particles of fuel ash, of a stream of hot product gas 1 coming from a process and guided in an upward stream against a fixed boundary 2 with subsequent deflection wherein the velocity of the stream of product gas and of the liquid and/or glutinous particles of fuel has contained therein in chamber 4 is lowered below the value of the velocity of descent of the liquid and/or glutinous particles of fuel ash before the fixed boundary is reached. <IMAGE>

Description

SPECIFICATION Method of preventing caking consisting of liquid and/or glutinous particles of fuel ash of a stream of product gas when flowing towards a fixed boundary The invention relates to a method of preventing caking, consisting of liquid and/or glutinous particles of fuel ash, of a hot stream of product gas coming from a gasification process and guided in an upward stream against a fixed boundary with subsequent deflection.

It is known that caking occurs in bends of conventional construction before the deflection of the stream of product gas containing liquid and/or glutinous particles of fuel ash, which caking can impair and disturb the course of operation of the gasification process in a manner which cannot be controlled.

It is the object of the present invention to develop a method whereby assurance is provided that caking of liquid and/or glutinous particles of fuel ash in a stream of product gas from a gasification process guided against a fixed boundary with subsequent deflection in the region of impingement on the fixed boundary is largely prevented.

This problem is solved in that the velocity of the stream of product gas and of the liquid and/or glutinous particles of fuel ash contained therein is lowered below the value of the velocity of descent of the liquid and/or glutinous particles of fuel ash before the fixed boundary is reached.

As a result, the effect is achieved that the liquid and/or glutinous particles of fuel ash sink down by their own weight and so only reach the fixed boundary after the deflection. Caking which occurs outside the region of impingement on the fixed boundary as a result of these means according to the invention can be removed in an advantageous manner by means of percussion or knocking devices and be carried out of the gas deflection device, in which case large pieces of this caking are prevented from falling back into the gasification process and leading to disturbances in operation.

In addition, as a result of the reduction in velocity of the flow of gas, a thorough mixing is achieved which leads to an equalization of the temperature profile of the product gas after its deflection.

One construction of apparatus suitable for carrying out the method of the invention will now be described, by way of example, with reference to the accompanying drawing: A hot stream of product gas 1 coming from a gasification process and conveying liquid and/or glutinous particles of fuel ash flows at a specific velocity v, from the bottom upwards in the direction of the fixed boundary 2. After the stream of product gas has emerged from the guide tube 3 into the chamber 4, its velocity is reduced, by enlargement of the free cross-sectional area of flow, to the value v2 which is below the value of the velocity of descent v8 of the liquid and/or glutinous particles of fuel ash.As a result, the still liquid and/or glutinous particles of fuel ash sink down, are carried by the deflected stream of product gas 1 outside the region of impingement 5 on the fixed boundary 2 and can cake there. This caking is removed from the fixed boundary by means of percussion or knocking devices 6 and carried out of the gas deflection device via an oblique surface 7 or by means of other devices.

1. A method of preventing caking, consisting of liquid and/or glutinous particles of fuel ash, of a hot stream of product gas coming from a gasification process and guided in an upward stream against a fixed boundary with subsequent deflection, characterised in that the velocity of the stream of product gas and of the liquid and/or glutinous particles of fuel ash contained therein is lowered below the value of the velocity of descent of the liquid and/or glutinous particles of fuel ash before the fixed boundary is reached.

2. A method of preventing caking of an upwardly directed stream of a hot product gas on the impingement area of a deflecting surface, as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Method of preventing caking consisting of liquid and/or glutinous particles of fuel ash of a stream of product gas when flowing towards a fixed boundary The invention relates to a method of preventing caking, consisting of liquid and/or glutinous particles of fuel ash, of a hot stream of product gas coming from a gasification process and guided in an upward stream against a fixed boundary with subsequent deflection. It is known that caking occurs in bends of conventional construction before the deflection of the stream of product gas containing liquid and/or glutinous particles of fuel ash, which caking can impair and disturb the course of operation of the gasification process in a manner which cannot be controlled. It is the object of the present invention to develop a method whereby assurance is provided that caking of liquid and/or glutinous particles of fuel ash in a stream of product gas from a gasification process guided against a fixed boundary with subsequent deflection in the region of impingement on the fixed boundary is largely prevented. This problem is solved in that the velocity of the stream of product gas and of the liquid and/or glutinous particles of fuel ash contained therein is lowered below the value of the velocity of descent of the liquid and/or glutinous particles of fuel ash before the fixed boundary is reached. As a result, the effect is achieved that the liquid and/or glutinous particles of fuel ash sink down by their own weight and so only reach the fixed boundary after the deflection. Caking which occurs outside the region of impingement on the fixed boundary as a result of these means according to the invention can be removed in an advantageous manner by means of percussion or knocking devices and be carried out of the gas deflection device, in which case large pieces of this caking are prevented from falling back into the gasification process and leading to disturbances in operation. In addition, as a result of the reduction in velocity of the flow of gas, a thorough mixing is achieved which leads to an equalization of the temperature profile of the product gas after its deflection. One construction of apparatus suitable for carrying out the method of the invention will now be described, by way of example, with reference to the accompanying drawing: A hot stream of product gas 1 coming from a gasification process and conveying liquid and/or glutinous particles of fuel ash flows at a specific velocity v, from the bottom upwards in the direction of the fixed boundary 2. After the stream of product gas has emerged from the guide tube 3 into the chamber 4, its velocity is reduced, by enlargement of the free cross-sectional area of flow, to the value v2 which is below the value of the velocity of descent v8 of the liquid and/or glutinous particles of fuel ash.As a result, the still liquid and/or glutinous particles of fuel ash sink down, are carried by the deflected stream of product gas 1 outside the region of impingement 5 on the fixed boundary 2 and can cake there. This caking is removed from the fixed boundary by means of percussion or knocking devices 6 and carried out of the gas deflection device via an oblique surface 7 or by means of other devices. CLAIMS

1. A method of preventing caking, consisting of liquid and/or glutinous particles of fuel ash, of a hot stream of product gas coming from a gasification process and guided in an upward stream against a fixed boundary with subsequent deflection, characterised in that the velocity of the stream of product gas and of the liquid and/or glutinous particles of fuel ash contained therein is lowered below the value of the velocity of descent of the liquid and/or glutinous particles of fuel ash before the fixed boundary is reached.

2. A method of preventing caking of an upwardly directed stream of a hot product gas on the impingement area of a deflecting surface, as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.