Storage bin type hot air powder feeding and pulverizing system adopting tertiary air heating

Abstract

The invention relates to the technical field of coal pulverizing, in particular to a storage bin type hot air powder feeding and pulverizing system adopting tertiary air for heating. The storage bin type hot air powder feeding and pulverizing system comprises a boiler, a fine powder separator for separating pulverized coal from tertiary air, a powder discharging fan for conveying the tertiary airand a tertiary air heater for heating the tertiary air, the boiler comprises a hearth and a combustor in communication with the front end of the hearth, and a tertiary air outlet of the fine powder separator is connected with the combustor through the powder discharging fan and the tertiary air heater in sequence. The tertiary air separated by the fine powder separator is heated and then sent to the combustor, so that the tertiary air can be used as secondary air of a main combustion area of the boiler, on one hand, the temperature of the tertiary air is increased, high-temperature combustionof the hearth is facilitated, and on the other hand, the secondary air proportion is increased, hearth air distribution is optimized, hearth organization combustion is facilitated, the pulverized coal, smoke and air are mixed more strongly, combustion in the hearth is stronger, and therefore the carbon content of fly ash is smaller, mechanical incomplete losses are smaller, and the combustion efficiency of the boiler is higher.

Description

technical field [0001] The invention relates to the technical field of coal-fired pulverization, in particular to a storage-type hot-air pulverization system heated by tertiary air. Background technique [0002] Thermal power units that burn anthracite and lean coal often use a storage-type hot air pulverization system. In the silo-type hot air pulverization system, the coal is dried and ground inside the coal mill, and the coal is dried by the hot air passing into the coal mill and the pulverized coal is sent out. The air flow passes through the coarse powder separator and the fine powder separator to the pulverized coal bin. The fine powder separator separates the pulverized coal from the air flow and stores it in the pulverized coal bin. The separated air flow is called the tertiary air (that is, exhausted air). The tertiary air is pressurized by the powder exhaust fan and enters the upper part of the boiler furnace. The pulverized coal is first stored in the pulverize...

AI Technical Summary

Problems solved by technology

The low-temperature tertiary air has adverse effects on the combustion efficiency of the boiler: 1. The tertiary air is at the uppermost part of the furnace, which is very close to the furnace outlet; 2. The tertiary air carries powder, the combustion temperature is low, the path of coal powder is short, and the combustion is insufficient, resulting in fly ash High carbon content; 3. The temperature of the tertiary air is low, which has a great impact on the furnace smoke and affects the combustion

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