Circular fluidizing bed combustion system with uniform airflow distributing device

Patent metadata

Field	Value
Publication number	US-10174936-B2
Application number	US-201615563456-A
Country	US
Kind code	B2
Filing date	Oct 29, 2016
Priority date	May 30, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A circular fluidizing bed combustion system with uniform airflow distributing device is provided. The system comprises a fluidizing bed and a uniform airflow distributing device. The fluidizing bed is comprised of a fluidizing bed boiler body, an airflow distributing plate and a plurality of air caps, wherein, the airflow distributing plate is provided inside the fluidizing bed boiler body and divides the inner space of the fluidizing bed boiler body into a fluidizing chamber which is located in the upper portion of the boiler body and an air chamber which is located in the lower portion of the boiler body, and the plurality of air caps are arranged on the airflow distributing plate for injecting the fluidizing air into the fluidizing chamber. The inner space of the air chamber is divided into a distributing chamber that is located under the airflow distributing plate and an air inlet chamber that is located on one side of the distributing chamber by means of a perforated plate. The distributing chamber is comprised of a front wall, two side walls, a top wall that extends upwards obliquely from the upside of the front wall, and a bottom wall extends downwards obliquely from the downside of the front wall. A first guide plate, a second guide plate and a third guide plate are installed in the distributing chamber. This system makes the flow of the fluidizing air entered into the fluidizing chamber through each air cap uniform, and enhances the combusting efficiency of the coal powder in the fluidizing chamber.

First claim

The invention claimed is:

1. A circular fluidizing bed combustion system with uniform airflow distributing device, comprising:
a fluidizing bed that is comprised of a fluidizing bed boiler body, an airflow distributing plate that is provided inside the fluidizing bed boiler body and divides the inner space of the fluidizing bed boiler body into a fluidizing chamber which is located in the upper portion of the boiler body and an air chamber which is located in the lower portion of the boiler body, and a plurality of air caps that are arranged on the airflow distributing plate for injecting the fluidizing air into the fluidizing chamber; and
a flue gas channel that is connected to the sidewall of the fluidizing bed boiler body, so as to exhaust the flue gas generated from fuel combustion in the fluidizing chamber;
wherein,
the inner space of the air chamber is divided into a distributing chamber that is located under the airflow distributing plate and an air inlet chamber that is located on one side of the distributing chamber by means of a perforated plate, the distributing chamber is comprised of a front wall, two side walls, and a top wall that extends upwards obliquely from the upside of the front wall, and a bottom wall that extends downwards obliquely from the downside of the front wall, a vertical distance H is defined between a first planar surface that passes through the extension end of the top wall and is parallel with the airflow distributing plate and a second planar surface that passes through the extension end of the bottom wall and is parallel with the airflow distributing plate, the perforated plate lies in the surface that passes through the extension ends of both top wall and bottom wall and is perpendicular with the first and second planar surfaces, a horizontal distance W is defined between the front wall of the distributing chamber and the perforated plate, at least a first guide plate and a second guide plate are installed in the distributing chamber, with the two side edges of the first guide plate and the second guide plate fixed to the two side walls of the distributing chamber respectively, the vertical distance between the bottom edge of the first guide plate and the first planar surface is 0.3-0.4H, the horizontal distance between the bottom edge of the first guide plate and the perforated plate is 0.2-0.3W, the first guide plate extends upwards and forwards by a distance of 0.1-0.2H at an angle of 70-80 degree from the bottom edge with respect to the second planar surface, the vertical distance between the bottom edge of the second guide plate and the first planar surface is 0.4-0.5H, the horizontal distance between the bottom edge of the second guide plate and the perforated plate is 0.4-0.6W, the second guide plate extends upwards and forwards by a distance of 0.13-0.18H at an angle of 75-85 degree from the bottom edge with respect to the second planar surface, wherein W:H is set to 1-1.5:1.

2. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 1 , wherein a third guide plate is further installed in the distributing chamber, the third guide plate is comprised of a straight guide plate and an arched guide plate that extends downwards and backwards from the bottom edge of the straight guide plate, the vertical distance between the bottom edge of the straight guide plate and the first planar surface is 0.6-0.7H, the horizontal distance between the bottom edge of the straight guide plate and the perforated plate is 0.7-0.8W, the straight guide plate extends upwards and forwards by a distance of 0.15-0.2H at an angle of 70-80 degree from the bottom edge with respect to the second planar surface, the arched guide plate is with a central angle of 80-100 degree and a radius of 0.05-0.1H.

3. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 2 , wherein several rows of rectangular holes are formed on the perforated plate along longitudinal direction from one side edge to the other, with each row of the rectangular holes comprised of several rectangular holes that are arranged sequentially from the upper edge to the lower edge of the perforated plate in vertical direction.

4. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 3 , wherein the long side of each rectangular hole is provided along the longitudinal direction of the perforated plate, the short side of each rectangular hole is provided in the vertical direction along the perforated plate, the length-width ratio for each rectangular hole is set to 3-5:1, and the several rows of rectangular holes are symmetrically arranged with respect to the vertical central line of the perforated plate.

5. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 4 , wherein two adjacent rows of rectangular holes situated on the same side with respect to the vertical central line of the perforated plate are staggered in vertical direction, each row of the rectangular holes comprises at least 8 rectangular holes, a row of central holes are provided from the upper edge to the lower edge on the perforated plate along the vertical central line, the row of central holes comprise at least 8 central holes, with each central hole being a circular or square hole.

6. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 5 , wherein the air inlet chamber of the air chamber is comprised of a top wall, a bottom wall, a back wall and two side walls, the top wall of the air inlet chamber is connected to the top wall of the distributing chamber, and the bottom wall of the air inlet chamber is connected to the bottom wall of the distributing chamber, the two side walls of the air inlet chamber are connected to the two side walls of the distributing chamber respectively, the back wall of the air inlet chamber and the front wall of the distributing chamber are provided opposing to each other in longitudinal direction of the air chamber, an air inlet port is provided on the top wall of the air inlet chamber adjacent to the back wall, an airflow shield is formed by the forward extension of the lower portion of the back wall, with the bottom edge of the airflow shield connected to the bottom wall of the air inlet chamber.

7. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 6 , wherein an airflow guiding device is provided on the bottom wall of the air inlet chamber, the airflow guiding device comprises a first airflow guiding surface and a second airflow guiding surface, and the bottom edge of the first airflow guiding surface is connected to the bottom wall and the first airflow guiding surface extends upwards and backwards from the bottom edge, the bottom edge of the second airflow guiding surface is connected to the bottom wall and the second airflow guiding surface extends upwards and forwards from the bottom edge, the top edge of the first airflow guiding surface is connected to the top edge of the second airflow guiding surface.

8. The circular fluidizing bed combustion system with uniform airflow distributing device according to claim 7 , wherein the second airflow guiding surface is an arc surface that extends upwards and forwards from the bottom edge, the chord of the arc surface is inclined with respect to the bottom wall of the air inlet chamber at an angle of 30-50 degree, the vertical distance between the top edge of the first airflow guiding surface and the bottom wall of the air inlet chamber is 0.2-0.3H, and the horizontal distance between the top edge of the first airflow guiding surface and the bottom edge

Assignees

• Univ Guangdong Technology

Inventors

• Liu Xiaozhou
• Zhang Yu
• Liu Wenxing

Classifications

• F23J15/022

  for removing solid particulate material from the gasflow · CPC title

• F23C10/02 Primary

  with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed · CPC title

• F23C7/008

  Flow control devices (F23C7/006 takes precedence) · CPC title

• F23C10/12 Primary

  the particles being circulated exclusively within the combustion zone · CPC title

• F23J3/02

  Cleaning furnace tubes; Cleaning flues or chimneys · CPC title