CN101879506B - Inertial elbow thick-thin powder separator - Google Patents

Abstract

The utility model relates to an inertial elbow powder concentration and thinness separation device, which belongs to the technical field of powder transportation and combustion. The device consists of a core barrel, an open diversion elbow and fins; the core barrel is a closed straight cylinder, one end of the open diversion elbow is connected to the core barrel, and the fins are fixed on the open diversion bend the sides of the head and stretch out. The section of the open diversion elbow is a non-closed arc or polygon. The invention has simple structure, good separation effect on the concentration of powder two-phase flow, uniform distribution of concentrated powder, and can be used in gas-solid transportation devices with elbow structure and requiring separation of concentration, such as concentration and light pulverized coal swirl In the burner and cement industry.

Description

An inertial elbow powder concentration separation device

technical field

The invention relates to a powder concentration separation device, which is particularly suitable for a gas-solid transportation device having an elbow structure and requiring concentration separation, and belongs to the technical field of powder transportation and combustion.

Background technique

In the pulverized coal burner and cement industry, thick and thin separation devices are often used to enrich the particles in the powder feeding pipeline to form two thick and thin streams. For example, in a pulverized coal burner, the powder feeding primary air passes through the burner with a specific structure, and the powder will be locally enriched, resulting in a separation of concentration and concentration. The formation of nitrogen oxides, as the combustion proceeds, oxygen gradually participates in the combustion, thereby reducing NOx while ensuring combustion efficiency.

In this type of device, the powder feeding pipeline generally has an elbow structure, and the particles will maintain the original trajectory at the elbow due to inertia, and will be enriched along the original flow direction in the straight section of the pipeline. Related studies have shown that the inertial enrichment effect of particles at the bend can be maintained for a longer distance. The effective use of the elbow enrichment effect of particles can not only achieve the purpose of concentration separation, but also simplify the structure of the separation device and reduce the cost. Especially in the pulverized coal burner, the effective use of the elbow structure can simplify the burner structure and ensure the separation effect of thick and thin.

However, the inertia of the elbow will cause the coal powder to be over-enriched in the elbow and the top of the pulverized feed pipe, and this over-enrichment phenomenon will be maintained to the outlet of the burner. Most of the pulverized coal is enriched in a small area, which will lead to unstable combustion, affect the efficiency of the thick and thin pulverized coal burner, and cause serious accidents such as coking at the burner outlet and burning burner components. In order to avoid this situation and ensure the effect of thick and thin separation at the same time, it is necessary to distribute the coal powder in the thick strand evenly along the ring direction of the burner pipe while the coal powder is efficiently separated from the thick and thin. Most of the existing inertial elbow separation technologies only rely on the elbow of the primary air duct, which is prone to excessive enrichment of coal powder. In order to improve the concentration separation effect and avoid excessive enrichment of coal powder, it is necessary to install an additional structure at the elbow of the primary air duct, so that it can not only make full use of the inertia of the elbow, but also overcome the excessive enrichment effect caused by the inertia of the elbow .

Contents of the invention

In order to effectively utilize the inertial separation characteristics of the gas-solid transportation pipeline elbow, simplify the structure of the separation device, and achieve the effect of concentration separation, the present invention proposes an inertial elbow powder concentration separation device.

Technical scheme of the present invention is as follows:

An inertial elbow powder concentration separation device is characterized in that the device is composed of a core barrel, an open diversion elbow and fins, the core barrel is a closed straight barrel, and one end of the open diversion elbow is connected to The core barrel is connected, and the fins are fixed on both sides of the open diversion elbow and extend outward.

The section of the open diversion elbow of the present invention is a non-closed circular arc or polygon, and the angle β of the open diversion elbow is 90°>β>10°, preferably β is 45°.

The technical feature of the present invention is that: the opening angle α is formed between the fin and the open diversion elbow, and 180°>α>0°, and the opening angle α is preferably 90°.

The present invention has the following advantages and outstanding effects: ①Using the effect of the particle inertia at the elbow of the gas-solid transportation pipeline to achieve the separation effect, the structure is simple; ②The open diversion elbow and the fin bend the gas-solid transportation pipeline The particle flow at the head is physically divided into two parts, which reduces the phenomenon of particle enrichment at the top of the elbow, and makes the concentrated particles evenly distributed in the subsequent straight pipe section, thus ensuring the uniform distribution of particles in the concentrated two-phase flow;③ The core barrel physically divides the gas-solid pipeline or the straight section of the primary air duct into two cavities, the inner and the outer, effectively preventing the re-mixing of the dense and light air streams.

Description of drawings

Figure 1 is a three-dimensional view of an inertial separation device.

Fig. 2 is a structural front view of the inertial separation device.

Fig. 3 is a structural side view of the inertial separation device.

Fig. 4 is a schematic diagram of an embodiment of an inertial elbow powder rich-lean separation device installed in a rich-lean swirl burner.

1-core barrel; 2-open diversion elbow; 3-fin; 4-swirl pulverized coal burner; 5-inertial elbow powder concentration separation device.

Detailed ways

The principle, specific structure and best implementation mode of the present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 is a three-dimensional view of the inertial elbow powder concentration separation device, and Figures 2 and 3 are the front view and side view of the device, respectively. The invention consists of a core barrel 1, an open diversion elbow 2 and fins 3. The core barrel 1 is a closed straight cylinder with a circular cross section, polygon or other closed shapes. The function of the core barrel is to physically separate the straight section of the powder feeding air duct into two cavities inside and outside. One end of the core barrel 1 is connected with the open diversion elbow 2. The cross-sectional shape of the open diversion elbow 2 is a part of the cross-sectional shape of the core barrel 1, but it is a non-closed structure, and its purpose is to block a part of the pulverized coal due to While the inertial movement reaches the top of the elbow of the primary air duct, the unblocked pulverized coal moves smoothly to the top of the elbow of the powder feeding pipeline under the action of inertia. The cross-section of the open diversion elbow 2 is generally a non-closed circular arc or polygon. The fins 3 are fixed on both sides of the open diversion elbow 2 and stretch outwards. Its function is to fully change the movement trajectory of a part of the pulverized coal so that these pulverized coal can flow along the bottom or fins of the open diversion elbow 2. The bottom of 3 moves to the outer wall of the core barrel 1 and the inner wall of the primary air duct to form a uniform thick powder flow. The fins 3 form a certain angle with the open diversion elbow 2, and the opening angle range is 180°>α>0°, and the opening angle is generally 90°, so that the powder can be evenly divided and enriched In different positions of the powder feeding pipeline. The open diversion elbow 2 is bent at a certain angle, so that the powder is smoothly divided into two streams along the incoming flow direction, and the damage to the incoming flow field and the motion inertia of the powder is avoided as much as possible. The open diversion elbow 2 The bending angle range is 90°>β>10°, preferably 45°.

Fig. 4 is a schematic diagram of an embodiment of an inertial elbow powder rich-lean separation device installed in a rich-lean swirl burner. Swirl burners are widely used in coal-fired boilers. Thick and light pulverized coal burners have the characteristics of low NOx emissions and small smoke deviation. The inertial elbow powder thick-lean separation device is installed in the primary air duct of the swirl burner, and the open diversion elbow 2 is arranged in the same direction as the elbow section of the primary air duct of the burner, and the fins 3 and the open guide Flow elbow 2 divides the elbow section of the primary air duct of the burner into upper and lower cavities. The pulverized coal goes up from the primary air pipe of the burner with the primary air, and after entering the elbow section, it is enriched to the top of the horizontal section of the primary air pipe under the action of inertia. However, due to the existence of the open diversion elbow 2 and the fin 3 The elbow section of the primary air duct is divided into upper and lower parts, and about half of the pulverized coal will move along the bottom of the fins. When the pulverized coal enters the horizontal section, it will gather at the two areas at the bottom of the fins and at three points at the top of the horizontal pipe, thereby reducing the side effect of the excessive enrichment of pulverized coal at the top of the horizontal pipe in the past. Subsequently, the core barrel 1 connected with the open diversion elbow 2 divides the horizontal section of the primary air duct into two channels, the inner and outer channels, most of the pulverized coal will move along the outer channel, and only about 1/5 of the powder will enter the core barrel internal channel, thereby forming two independent thick and thin pulverized coal airflows inside and outside the core barrel 1. Due to the physical separation of the core barrel, the concentrated powder and light powder streams will no longer be mixed until they leave the burner and enter the furnace for combustion. The existence of the inertial elbow ensures that the powder feeding primary air forms two streams of thick and thin air, achieving the effects of stable combustion and low _NOx emissions.

The powder concentration separation device with elbow can also be used in other powder feeding pipelines with elbows to achieve the effect of separating the powder into two streams of thick and thin in the future and ensuring the uniform distribution of powder in the concentrated airflow.

Claims (5)

1. inertial elbow thick-thin powder separator; It is characterized in that: this device is made up of core bucket (1), open water conservancy diversion elbow (2) and fin (3); Said core bucket (1) is closed straight tube; One end of open water conservancy diversion elbow is connected with core tube (1), and the cross sectional shape of open water conservancy diversion elbow is the part of core bucket cross sectional shape, but is non-enclosed construction; Said fin (3) is fixed on the both sides of open water conservancy diversion elbow (2), and outwards stretches.

2. a kind of inertial elbow thick-thin powder separator as claimed in claim 1 is characterized in that: the cross section of described open water conservancy diversion elbow is non-closed circular arc or polygon, and the bent angle β of open water conservancy diversion elbow is 90 °＞β＞10 °

3. a kind of inertial elbow thick-thin powder separator as claimed in claim 2 is characterized in that: the bent angle β of said open water conservancy diversion elbow (2) is 45 °.

4. like claim 1,2 or 3 described a kind of inertial elbow thick-thin powder separators, it is characterized in that: form subtended angle a between described fin (3) and the open water conservancy diversion elbow (2), and 180 °＞a＞0 °.

5. a kind of inertia elbow separator as claimed in claim 4 is characterized in that: the subtended angle a that forms between described fin (3) and the open water conservancy diversion elbow (2) is 90 °.

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