Primary cold air pipe structure for circulating fluidized bed

Abstract

The utility model provides a primary cold air pipe structure for a circulating fluidized bed, which is not easy to flow backwards and block, and can prolong the service life of a material returning air pipe. The device comprises a horizontal pipe, an inlet of the horizontal pipe is connected with an output pipeline of a primary fan, an outlet of the horizontal pipe is connected with a cold air opening in the pipe wall of a material returning air pipe, and the device is characterized in that the horizontal pipe comprises a first horizontal pipe, an outlet of the first horizontal pipe is connected with an inlet of an inclined pipe, and the inclined pipe inclines upwards; the inclined pipe is a conical pipe with the lower end large in diameter and the upper end small in diameter, the included angle between the center line of the inclined pipe and the center line of the horizontal pipe is an obtuse angle, an outlet of the inclined pipe is connected with an inlet of the second horizontal pipe, and the outlet of the inclined pipe is an oval opening. After the inlet of the second horizontal pipe covers the oval outlet part of the inclined pipe, the rest uncovered part is covered by a sealing plate, and the pipe diameter of the second horizontal pipe is smaller than that of the material returning air pipe.

Description

Technical Field

[0001] The utility model relates to the technical field of circulating fluidized bed boilers, in particular to a primary cooling air duct structure for a circulating fluidized bed. Background Art

[0002] In the circulating fluidized bed boiler system, the primary fan will send part of the air to the air preheater of the circulating fluidized bed to heat it into hot air for drying and conveying coal powder, and the other part is used as cold air to mix with the return air to adjust the return air temperature and bed temperature to maintain the fluidization of the bed material. The primary cold air duct for the circulating fluidized bed is usually directly connected to the return air duct. This is the dense phase area of ​​the boiler. The temperature of the return particles in the furnace is high and the return air pressure is high. The mixing disturbance of the primary cold air and the return air is large. The return air and return particles are easy to flow back into the primary cold air duct, causing the primary cold air duct to be blocked. In addition, the primary cold air has a strong impact on the return air duct, which reduces the service life of the return air duct. Utility Model Content

[0003] Aiming at the shortcomings of the existing primary cooling air duct for a circulating fluidized bed, that the return air and return particles are easily backflowed into the primary cooling air duct, causing the primary cooling air duct to be blocked, and the primary cooling air has a strong impact on the return air duct, thereby reducing the service life of the return air duct, the utility model provides a primary cooling air duct structure for a circulating fluidized bed, which is not easy to backflow and block, and can increase the service life of the return air duct.

[0004] A primary cold air duct structure for a circulating fluidized bed comprises a horizontal pipe, the inlet of the horizontal pipe is connected to the output pipe of a primary fan, and the outlet of the horizontal pipe is connected to the cold air outlet of the wall of a return air duct, characterized in that: the horizontal pipe comprises a first horizontal pipe, the outlet of the first horizontal pipe is connected to the inlet of an inclined pipe, the inclined pipe is inclined upward, and the inclined pipe is a conical pipe with a large diameter at the lower end and a small diameter at the upper end, the angle between the center line of the inclined pipe and the center line of the horizontal pipe is an obtuse angle, the outlet of the inclined pipe is connected to the inlet of a second horizontal pipe, and the outlet of the inclined pipe is an elliptical opening, after the inlet of the second horizontal pipe covers part of the elliptical outlet of the inclined pipe, the remaining uncovered part is covered with a sealing plate, and the diameter of the second horizontal pipe is smaller than the diameter of the return air duct.

[0005] It is further characterized by:

[0006] The first horizontal pipe is provided with a horizontal gate valve.

[0007] In the above structure of the utility model, the inclined tube is inclined upward to increase the resistance, which can reduce the wind speed and play a buffering role. When the wind in the inclined tube enters the second horizontal tube, it collides and resists at the position of the sealing plate, and part of the wind returns, forming a small vortex here, which reduces the wind speed of the inclined tube again, reduces the impact of the primary cold wind on the return material air duct, and improves the service life of the return material air duct. The inclined tube is a tapered tube with a large diameter at the lower end and a small diameter at the upper end, so that the diameter of the inclined tube gradually decreases. The diameter of the second horizontal tube is smaller than the outlet diameter of the inclined tube and the diameter of the return material air duct, which increases the pressure inside the primary cold air duct, prevents the gas and particles in the return material air duct from flowing back into the primary cold air duct, and prevents the primary cold air duct from being blocked. The manual gate valve can further prevent backflow, and when the primary cold air duct leaks, closing the manual gate valve can effectively isolate the primary cold air duct for easy maintenance, further improving the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram of the location of the utility model in the system;

[0009] Figure 2 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0010] See Figure 1 , Figure 2 The utility model provides a primary cold air duct structure for a circulating fluidized bed, which comprises a horizontal pipe 1, the inlet of the horizontal pipe 1 is connected to the output pipe 2 of the primary fan, the outlet of the horizontal pipe 1 is connected to the cold air outlet of the wall of the return air duct 3, and the horizontal pipe 1 comprises a first horizontal pipe 11, the outlet of the first horizontal pipe 11 is connected to the inlet of an inclined pipe 12, and the inclined pipe 12 is inclined upward. The inclined pipe can reduce the wind speed, play a buffering role, and reduce the impact of the primary cold air on the return air duct. The inclined pipe 12 is a tapered pipe with a large diameter at the lower end and a small diameter at the upper end. The angle between the center line of the inclined pipe 12 and the center line of the horizontal pipe 1 is an obtuse angle. The outlet of the inclined pipe 12 is connected to the inlet of the second horizontal pipe 13, and the outlet of the inclined pipe 12 is an elliptical outlet. After the inlet of the second horizontal pipe 13 covers the part of the elliptical outlet of the inclined pipe 12, the remaining uncovered part is covered with a sealing plate 14. When the wind in the inclined pipe 12 enters the second horizontal pipe 13, it collides and resists at the position of the sealing plate 14, and part of the wind returns, forming a small vortex here, which reduces the wind speed of the inclined pipe 12. The diameter of the second horizontal pipe 13 is smaller than the diameter of the return air pipe 3. The smaller diameter increases the pressure in the primary cold air pipe, which can effectively prevent the gas and particles in the return air pipe 3 from flowing back into the primary cold air pipe to prevent blockage.

[0011] The first horizontal pipe 11 is provided with a horizontal gate valve 4 for further preventing backflow, and when the primary cold air duct 2 leaks, closing the manual gate valve can effectively isolate the primary cold air duct for easy maintenance.

Claims

1. A primary cooling air duct structure for a circulating fluidized bed, comprising a horizontal pipe, the inlet of the horizontal pipe being connected to the output pipe of a primary fan, the outlet of the horizontal pipe being connected to the cold air outlet of the wall of the return air duct, characterized in that: The horizontal pipe includes a first horizontal pipe, the outlet of the first horizontal pipe is connected to the inlet of the inclined pipe, the inclined pipe is inclined upward, and is a tapered pipe with a large diameter at the lower end and a small diameter at the upper end. The angle between the center line of the inclined pipe and the center line of the horizontal pipe is an obtuse angle. The outlet of the inclined pipe is connected to the inlet of the second horizontal pipe, and the outlet of the inclined pipe is an elliptical opening. After the inlet of the second horizontal pipe covers part of the elliptical outlet of the inclined pipe, the remaining uncovered part is covered with a sealing plate, and the diameter of the second horizontal pipe is smaller than the diameter of the return air duct.

2. The primary cooling air duct structure for a circulating fluidized bed according to claim 1, characterized in that: The first horizontal pipe is provided with a horizontal gate valve.

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