CN201190993Y - Pulverized coal combustion device for small and medium-sized boilers - Google Patents

Abstract

The utility model provides a middle-size and small-size boiler pulverized coal burner, includes pulverized coal preparation system, buggy conveying system, pulverized coal burner and pulverized coal combustion chamber, and its main points are: the inner cavity of the pulverized coal burner is a cylindrical cavity formed by a fire-resistant layer, and an annular water-cooling cavity is arranged on the outer side of the fire-resistant layer; the input end of the pulverized coal burner is connected with the rotational flow volute and the ignition hole through a flange, a horn nozzle is arranged at the communication part of the inner cavity of the rotational flow volute and the inner cavity of the pulverized coal burner, and a blunt body is arranged in the inner cavity of the rotational flow volute; a secondary air port is arranged on a fire-resistant layer of the pulverized coal burner; the inner cavity of the pulverized coal burner is communicated with a pulverized coal combustion chamber in the boiler body through a burner smoke outlet, the lower part of the pulverized coal combustion chamber is a slag collecting chamber, the bottom of the pulverized coal combustion chamber is provided with a slag remover, and the upper part of the pulverized coal combustion chamber is provided with a smoke outlet. The utility model has the characteristics of coal burn-off rate is high, boiler thermal efficiency is high.

Description

A pulverized coal combustion device for medium and small boilers

technical field

The utility model relates to a pulverized coal combustion device in a medium and small boiler combustion system.

Background technique

my country's large-scale boilers are mainly circulating fluidized bed boilers, with high technical maturity, while chain furnaces are generally used in the combustion systems of a large number of small and medium-sized boilers. Huge waste. The main problems are: 1. Coal is difficult to ignite, and the ignition point moves backward, resulting in insufficient combustion time. The fixed carbon content in the ash is as high as 10-25%, and the loss of incomplete combustion is large, resulting in low coal burnout rate; 2. Excessive air The coefficient is high, generally 1.3 to 1.5, and even 1.5 to 1.8 in actual operation, resulting in increased flue gas heat loss and low boiler thermal efficiency.

Contents of the invention

The purpose of the utility model is to provide a pulverized coal combustion device for small and medium-sized boilers with high coal burnout rate and high boiler thermal efficiency.

The technical scheme of the utility model is: the utility model comprises a pulverized coal preparation system, a pulverized coal conveying system, a pulverized coal burner and a pulverized coal combustion chamber. The pulverized coal preparation system consists of a conveyor belt, a coal crusher, a pulverized coal hoist, a pulverized coal hopper, a vibrating coal feeder, a Raymond mill, a cyclone separator, a pulverized coal hoist and a pulverized coal bin. The pulverized coal conveying system is composed of a pulverized coal quantitative device and a primary wind coal pipeline. The inner cavity of the pulverized coal burner is a cylindrical cavity formed by a refractory layer, and an annular water cooling chamber is arranged outside the refractory layer. The input end of the pulverized coal burner is connected with the swirl volute and the ignition hole through the flange. The primary air coal pipeline of the pulverized coal conveying system communicates with the inner cavity of the swirl volute, and the inner cavity of the swirl volute is burned with the pulverized coal. A trumpet nozzle is arranged at the intercommunication of the inner cavity of the device, and a blunt body is installed in the inner cavity of the swirl volute, and the end of the blunt body extending into the inner cavity of the pulverized coal burner is in the shape of a trumpet. The outer end of the ignition hole is connected with the ignition hole cover by threads. There is a secondary tuyere on the refractory layer of the pulverized coal burner. The secondary tuyere is tangent to the inner wall of the cylindrical refractory layer and forms a certain angle with the axis of the cylindrical refractory layer. The secondary air duct is connected. A cooling water inlet pipe and a cooling water outlet pipe are arranged in the water cooling cavity. The inner cavity of the pulverized coal burner communicates with the pulverized coal combustion chamber in the boiler body through the outlet of the burner flue gas. The lower part of the pulverized coal combustion chamber is a slag collection chamber. The upper part of the combustion chamber is provided with a flue gas outlet.

The primary air powder from the pulverized coal conveying system enters into the inner cavity of the pulverized coal burner through the trumpet nozzle in a spiral motion under the action of the swirling volute, and ignites the pulverized coal through the ignition hole. After entering the normal combustion condition, the secondary air enters the pulverized coal burner through the secondary air port to form a helical trajectory, and at the same time, under the joint action of the blunt body, a high-temperature flue gas is formed in the area near the horn-shaped end of the blunt body. The recirculation zone ignites the pulverized coal in the recirculation zone of the high-temperature flue gas, and the pulverized coal in the pulverized coal burner moves along the helical trajectory and burns rapidly, and the formed high-temperature flue gas carries unburned semi-coke particles through The flue gas outlet of the burner enters the pulverized coal combustion chamber in the boiler body for complete combustion, and the generated ash is agglomerated under the action of the high-temperature flue gas to generate dust with large particles. Due to the large space of the pulverized coal combustion chamber, The flow rate of the high-temperature flue gas drops suddenly, and part of the ash and slag settles to the lower slag collection chamber under the action of gravity; Under the action, it is separated and falls into the lower slag collection chamber. The fixed carbon content in the ash is less than 2%, and the ash is discharged out of the furnace through the slag remover, and the high-temperature flue gas after the slag removal enters the boiler through the flue gas outlet for heating. After testing, the utility model can make the burnout rate of coal reach more than 98%, and the thermal efficiency of the boiler can reach 90%.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic structural view of a pulverized coal burner and a pulverized coal combustion chamber.

The part numbers in the drawings are: 1 is the conveyor belt, 2 is the coal crusher, 3 is the coal crushing hoist, 4 is the crushing coal hopper, 5 is the vibrating coal feeder, 6 is the Raymond mill, 7 is the cyclone separator , 8 is the pulverized coal elevator, 9 is the pulverized coal bin, 10 is the pulverized coal quantitative device, 11 is the boiler body, 12 is the secondary air duct, 13 is the pulverized coal burner, 14 is the secondary air coal pipeline, and 15 is the ignition Hole cover, 16 is ignition hole, 17 is blunt body, 18 is swirl volute, 19 is flange, 20 is trumpet nozzle, 21 is cooling outlet pipe, 22 is secondary air outlet, 23 is refractory layer, 24 is water cooling Cavity, 25 are cooling inlet pipes, 26 are burner flue gas outlets, 27 are slag collecting chambers, 28 are flue gas outlets, and 29 are slag removers.

Detailed ways

See Fig. 1 and Fig. 2, the utility model comprises pulverized coal preparation system, pulverized coal delivery system, pulverized coal burner and pulverized coal combustion chamber. The pulverized coal preparation system consists of a conveyor belt 1, a coal crusher 2, a pulverized coal hoist 3, a pulverized coal hopper 4, a vibrating coal feeder 5, a Raymond mill 6, a cyclone separator 7, a pulverized coal hoist 8 and a pulverized coal bin 9 composition. The pulverized coal delivery system is composed of a pulverized coal quantitative device 10 and a primary air coal pipeline 14 . The inner cavity of the pulverized coal burner 13 is a cylindrical cavity formed by a refractory layer 23 , and an annular water cooling cavity 24 is arranged outside the refractory layer 23 . The input end of the pulverized coal burner 13 is connected with the swirl volute 18 and the ignition hole 16 through the flange 19, and the primary wind coal pipeline 14 of the pulverized coal delivery system communicates with the inner cavity of the swirl volute 18, and the swirl volute 18 A trumpet nozzle 20 is established at the inner cavity of the inner cavity of the pulverized coal burner 13, and a blunt body 17 is installed in the inner cavity of the swirl volute 18, and the blunt body 17 extends into one end of the inner cavity of the pulverized coal burner 13 It is trumpet-shaped. The outer end of ignition hole 16 is connected with ignition hole cover 15 by screw thread. The refractory layer 23 of the pulverized coal burner 13 is provided with a secondary tuyere 22, which is tangent to the inner cavity of the pulverized coal burner 13 and forms a certain angle with the axis of the cylindrical cavity. The secondary air pipe 12 outside the pulverized burner 13 is connected. A cooling water inlet pipe 25 and a cooling water outlet pipe 21 are provided in the water cooling chamber 24 . The inner cavity of the pulverized coal burner 13 communicates with the pulverized coal combustion chamber in the boiler body 11 through the burner flue gas outlet 26. The lower part of the pulverized coal combustion chamber is a slag collection chamber 27, and a slag remover is installed at the bottom of the pulverized coal combustion chamber. 29. A flue gas outlet 28 is provided on the upper part of the pulverized coal combustion chamber.

Claims (1)

1. A small and medium-sized boiler pulverized coal combustion device, including a pulverized coal preparation system, a pulverized coal conveying system, a pulverized coal burner and a pulverized coal combustion chamber. The pulverized coal preparation system consists of a conveyor belt, a coal crusher, a pulverized coal hoist, Composed of broken coal hopper, vibrating coal feeder, Raymond mill, cyclone separator, pulverized coal elevator and pulverized coal bin, pulverized coal conveying system is composed of pulverized coal quantitative device, primary wind coal pipeline; its characteristic is: pulverized coal combustion The inner cavity of the burner is a cylindrical cavity formed by a refractory layer, and an annular water cooling chamber is arranged outside the refractory layer. The input end of the pulverized coal burner is connected with the swirling volute and the ignition hole through a flange, and the pulverized coal conveying system The primary wind coal pipeline communicates with the inner cavity of the swirl volute, and a trumpet nozzle is provided at the place where the inner cavity of the swirl volute communicates with the inner cavity of the pulverized coal burner, and a blunt body is installed in the inner cavity of the swirl vortex. One end of the body protruding into the inner cavity of the pulverized coal burner is trumpet-shaped, and the outer end of the ignition hole is connected with the ignition hole cover through threads. The inner wall of the refractory layer is tangent to the axis of the cylindrical refractory layer and forms a certain angle with the axis of the cylindrical refractory layer. The secondary air outlet is connected to the secondary air pipe outside the pulverized coal burner. There are cooling water inlet pipes and cooling water outlet pipes in the water cooling chamber. The inner cavity of the burner communicates with the pulverized coal combustion chamber in the boiler body through the outlet of the burner flue gas. The lower part of the pulverized coal combustion chamber is a slag collection chamber. The upper part is equipped with a flue gas outlet.

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