US 6,199,494 B1Granted

Method of improving the performance of a cyclone furnace for difficult to burn materials, and improved cyclone furnace thereof

OwnerEdwin M. Griffininventor

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Abstract

The firing performance of a radial, scroll, or vortex cyclone furnace can be improved when firing difficult to burn materials having a relatively low heating value or a relatively high moisture content, such as sub-bituminous and lignite coals. This can be achieved by introducing additionally heated primary air into the burner of the radial and vortex cyclone furnace or separately introducing preheated or additionally heated auxiliary air into the scroll burner. Moreover, additionally heated tertiary air can be introduced into the radial and scroll burners to further improve firing performance. Moreover, additionally heated primary air can be mixed with the coal before introducing the mixture into the scroll burner to further improve firing performance.

Claims32

Dependent claims

A method of improving the performance of a cyclone furnace having a vortex or radial burner when firing difficult to burn materials having a relatively low heating value or a relatively high moisture content, wherein the furnace has a barrel having a tubular wall with an upstream wall and a downstream wall, the tubular wall, the upstream wall, and the downstream wall defining a combustion chamber, the upstream wall having an inlet that introduces a combined crushed solid fuel and air into the combustion chamber, and the downstream wall having an exhaust outlet that exhausts combusted products;

the burner extending outwardly from the upstream wall, away from the barrel, the burner having a cylindrical wall aligned with the upstream wall inlet, and an endwall closing an outer end of the burner cylindrical wall opposite the upstream wall inlet, wherein the burner cylindrical wall has a primary air inlet that introduces, substantially tangentially to the burner cylindrical wall to impart a swirl, primary air that has been preheated to a preheat temperature, which is substantially above an ambient temperature, wherein the barrel tubular wall has a secondary air inlet that introduces, substantially tangentially to the barrel tubular wall to impart a swirl in the barrel, secondary air that also has been preheated to the preheat temperature, wherein the burner has a fuel inlet that introduces the crushed solid fuel, the method comprising:
additionally heating the preheated primary air to a temperature higher than the preheat temperature;
and
introducing the additionally heated primary air into the primary air inlet, the preheated secondary air into the secondary air inlet, and the crushed solid fuel into the fuel inlet,
wherein the additionally heated primary air introduced into the burner causes rapid ignition and thus more nearly complete combustion within the cyclone furnace of the difficult to burn material.

2 more elements

A cyclone furnace having one of a radial burner and a vortex burner, which furnace has a barrel having a tubular wall with an upstream wall and a downstream wall, the tubular wall, the upstream wall, and the downstream wall defining a combustion chamber, the upstream wall having an inlet that introduces a combined crushed solid fuel and air into the combustion chamber, and the downstream wall having an exhaust outlet that exhausts combusted products;

the burner extending outwardly from the upstream wall, away from the barrel, the burner having a cylindrical wall aligned with the upstream wall inlet, and an endwall closing an outer end of the burner cylindrical wall opposite the upstream wall inlet, wherein the burner cylindrical wall has a primary air inlet that introduces, substantially tangentially to the cylindrical wall to impart a swirl, primary air that has been preheated to a preheat temperature, which is substantially above an ambient temperature, wherein the barrel tubular wall has a secondary air inlet that introduces, substantially tangentially to the tubular wall to impart a swirl in the barrel, secondary air that also has been preheated to the preheat temperature, wherein the burner has a fuel inlet that introduces the crushed solid fuel;
a primary air duct that conveys the preheated primary air to the primary air inlet;
and a secondary air duct that conveys the preheated secondary air to the secondary air inlet;
and a fuel duct that conveys the crushed solid fuel to the fuel inlet, the cyclone furnace further comprising:
an auxiliary heater in a path of the primary air duct for heating the preheated primary air entering the primary air inlet to a temperature higher than the preheat temperature to cause rapid ignition and thus more nearly complete combustion within the cyclone furnace of difficult to burn materials having a relatively low heating value or a relatively high moisture content.

2 more elements

A vortex or radial cyclone furnace comprising:

a barrel having a tubular wall with an upstream wall and a downstream wall, the tubular wall, the upstream wall, and the downstream wall defining a combustion chamber, the upstream wall having an inlet for introducing a combined crushed solid fuel and air into the combustion chamber, and the downstream wall having an exhaust outlet for exhausting combusted products;
a vortex or radial burner extending outwardly from the upstream wall, away from the barrel, the burner having a cylindrical wall aligned with the upstream wall inlet, and an endwall closing an outer end of the burner cylindrical wall opposite the upstream wall inlet,
wherein the burner cylindrical wall has a primary air inlet that introduces, substantially tangentially to the cylindrical wall to impart a swirl, primary air that has been preheated to a preheat temperature, which is substantially above an ambient temperature,
wherein the barrel tubular wall has a secondary air inlet that introduces, substantially tangentially to the tubular wall to impart a swirl in the barrel, secondary air that also has been preheated to the preheat temperature,
wherein the burner has a fuel inlet that introduces the crushed solid fuel;
a primary air duct that conveys the preheated primary air to the primary air inlet;
a secondary air duct that conveys the preheated secondary air to the secondary air inlet;
a fuel duct that conveys the crushed solid fuel to the third inlet;
and
an auxiliary heater in a path of the primary air duct for heating the preheated primary air entering the primary air inlet to a temperature higher than the preheat temperature to cause rapid ignition and thus more nearly complete combustion within the cyclone furnace of difficult to burn materials having a relatively low heating value or a relatively high moisture content.

7 more elements

Dependencies are inferred from the claim text.