CN221648525U - A closed conveying device for biomass fuel blending - Google Patents

Abstract

The utility model relates to the technical field of boiler co-combustion, in particular to a biomass fuel co-combustion closed conveying device. The biomass fuel blending combustion closed conveying device comprises a primary air pipeline, wherein an auxiliary air cylinder is arranged on the primary air pipeline, and an air gun assembly for intermittently transmitting air guns for the primary air pipeline is arranged in the auxiliary air cylinder. According to the biomass fuel blending combustion closed type conveying device, the air cannon component is matched with the air in the pneumatic conveying system, so that a period of air flow enhancement time period is provided in the primary air pipeline at intervals to impact materials, the air flow of hot air reversely-filled along the primary air pipeline is easily caused by high temperature at the burner port of the boiler, and the hidden danger of blockage or slow blanking at the joint of the burner and the primary air pipeline of the boiler is eliminated.

Description

A closed conveying device for biomass fuel blending

Technical Field

The utility model relates to the technical field of boiler blending, and in particular to a closed conveying device for blending biomass fuel.

Background Art

At present, the biomass blending technology implemented for coal-fired power plant boilers at home and abroad mainly adopts pneumatic conveying, which is divided into dilute phase conveying and dense phase conveying. However, due to the low density of biomass fuel, dense phase conveying often has problems such as low conveying efficiency. For this reason, dilute phase conveying is often used for biomass fuel transportation at home and abroad, and the material-gas ratio of the conveyed material is generally controlled at around 3-8. Although it is feasible to use pneumatic conveying to achieve the blending process of biomass fuel, and it is also the most commonly used method at this stage, this technology still has the following defects:

1. The biomass blending system is often modified on the basis of the existing boiler unit. Due to factors such as construction site restrictions, the biomass storage bin and other biomass fuel storage devices are far away from the boiler unit, and the farthest distance may exceed 300m. The long transportation distance is bound to increase the pneumatic transportation operation resistance and increase the system operation cost;

2. Due to the long conveying distance and large pipeline resistance, a fan with a higher pressure head is required to provide power. At this time, the sealing of the discharge valve is very important. If the sealing is not good, it will cause the conveying air to leak, and seriously affect the system unloading;

3. The pneumatic conveying system needs to maintain a high conveying wind speed during operation, otherwise it will cause the conveying pipeline to be blocked. However, since the pneumatic conveying pipeline is long, it is difficult to determine the location of the blockage. When the system is blocked, it is difficult to handle. Especially when the moisture content of the biomass material is high and the particle size is large, the probability of pipeline blockage will increase significantly.

4. When the pneumatic conveying velocity is high, it will cause serious wear on the pipeline, especially in the elbow and other areas. All elbows and valves in the conveying system need to use wear-resistant materials, such as wear-resistant ceramic elbows and ceramic valves, which will greatly increase the investment cost of the system.

5. Since the boilers of coal-fired power plants are relatively large, multiple delivery pipelines need to be set up to ensure stable combustion of the boilers. For example, each layer of a four-corner tangential boiler needs to be equipped with at least 2 or 4 burners, and each layer of a front and rear wall-hedge boiler needs to be equipped with a certain number of burners, which further increases the investment cost of the system;

6. Due to the high volatile content of biomass fuel, the pneumatic conveying process needs to reduce the conveying air temperature as much as possible. For this reason, it is necessary to add air cooling to cool the high-temperature air generated by the high-pressure fan. On the one hand, this process will increase the investment and system operating costs. On the other hand, when the cooler leaks, the water in the cooler will enter the conveying air, and then after mixing with the biomass fuel, it will greatly increase the risk of blockage in the conveying system and affect the safe and stable operation of the system.

In response to the above problems, a Chinese patent with announcement number CN117722694A proposes a patent named a biomass blending fuel delivery system and a biomass blending system. The patent includes a multi-stage closed conveying device, and the closed conveying devices of each stage are connected in series in the direction of the primary air duct from the fuel storage bin to the boiler burner. The feed port of the first-stage closed conveying device is connected with the discharge port of the fuel storage bin, and the discharge port of the last-stage closed conveying device is connected with the primary air duct of the boiler burner. In the above-mentioned biomass blending fuel delivery system, a multi-stage series of closed conveying devices is used instead of pneumatic conveying to carry out long-distance transportation of biomass fuel. The multi-stage closed conveying devices are connected in series in sequence to achieve long-distance transportation of materials, and the problem of greater resistance as the longer the distance is, which will not occur like the pneumatic conveying device; however, since the discharge port of the second unloading system is connected with the primary air duct of the boiler burner, the burner port of the boiler is prone to cause hot gas to be backflowed along the primary air duct due to high temperature, thereby causing the connection between the boiler burner and the primary air duct to be blocked or the hidden danger of slow material dropping.

Therefore, it is necessary to provide a new biomass fuel blending closed conveying device based on the CN117722694A patent to solve the above technical problems.

Utility Model Content

In order to solve the above technical problems, the utility model provides a closed conveying device for biomass fuel blending.

The biomass fuel blending closed conveying device provided by the utility model comprises a primary air duct, an air-assisting cylinder is installed on the primary air duct, and an air cannon assembly for intermittently firing an air cannon for the primary air duct is arranged in the air-assisting cylinder;

The air gun assembly includes an elastic pleated airbag, a solenoid exhaust valve is fixedly installed on the front end surface of the elastic pleated airbag, and an air pressure plate is fixedly installed on the rear end of the elastic pleated airbag, a spring elastically connected to the inner wall of the air-assisting cylinder is installed on the air pressure plate, an air pump is installed on the air-assisting cylinder, and the output end of the air pump is connected to the air inlet of the elastic pleated airbag through a conduit.

Preferably, an annular plate is fixedly embedded in the air-assisting cylinder near the cylinder mouth, the inner plate wall of the annular plate is fixedly connected to the bag wall of the elastic pleated airbag equipped with an electromagnetic exhaust valve, and the electromagnetic exhaust valve is located in the annular cavity of the annular plate.

Preferably, one end of the spring is fixedly connected to the inner cylinder wall of the air-assisting cylinder, and the other end of the spring is fixedly connected to the air compression plate.

Preferably, the mouth of the air-assisting cylinder is fixedly connected to one end of the primary air duct via a flange.

Preferably, a variable frequency discharge valve is installed on one side of the primary air duct close to the air-assisting cylinder.

Preferably, an annular cover connected to the internal volume of the primary air duct is installed on the primary air duct, and an inner ring plate is fixedly engaged on the side of the annular cover close to the air-assisting cylinder, and an air inlet pipe is installed on the annular cover.

Preferably, the annular cover is located on the primary air duct between the variable frequency discharge valve and the air-assisting cylinder.

Compared with the related art, the biomass fuel blending closed conveying device provided by the utility model has the following beneficial effects:

The utility model starts the air pump to inflate the elastic pleated airbag. Since the front end surface of the elastic pleated airbag is restricted by the annular plate, the elastic pleated airbag abuts against the air pressure plate and compresses the spring after inflation. After the elastic pleated airbag expands to a predetermined degree, the electromagnetic exhaust valve is opened. At this time, the elastic pleated airbag is quickly exhausted and under the elastic force of the compression spring, the gas in the elastic pleated airbag quickly rushes into the primary air duct. Then the electromagnetic exhaust valve is closed and the air pump is turned on again for inflation. This reciprocating process cooperates with the gas in the pneumatic conveying system, so that there is a period of time of enhanced airflow in the primary air duct at regular intervals to impact the material, which greatly suppresses the airflow of hot gas backflowing along the primary air duct due to the high temperature at the burner port in the boiler, and eliminates the hidden dangers of blockage or slow material dropping at the connection between the boiler burner and the primary air duct.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a preferred embodiment of a closed type conveying device for blending biomass fuel provided by the utility model;

FIG2 is a schematic cross-sectional view of the structure shown in FIG1 ;

FIG3 is a schematic diagram of the structure of the gas gun assembly in the gas cylinder shown in FIG2;

FIG4 is a schematic structural diagram of the primary air duct shown in FIG1 ;

FIG. 5 is a schematic cross-sectional structural diagram of the primary air duct shown in FIG. 4 .

Numbers in the figure: 1, primary air duct; 11, variable frequency unloading valve; 12, annular cover; 121, inner ring plate; 13, air inlet pipe; 2, air cylinder; 21, annular plate; 3, air gun assembly; 31, elastic pleated airbag; 32, electromagnetic exhaust valve; 33, air pressure plate; 34, spring; 35, air pump.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

The specific implementation of the present utility model is described in detail below in conjunction with specific embodiments.

Please refer to Figures 1 to 5. An embodiment of the utility model provides a closed biomass fuel blending and conveying device, which includes: a primary air duct 1, an air assist cylinder 2 and an air gun assembly 3.

In the embodiments of the utility model, please refer to Figures 1 to 5, an air-assisting cylinder 2 is installed on the primary air duct 1, a variable frequency discharge valve 11 is installed on the side of the primary air duct 1 close to the air-assisting cylinder 2, and an annular cover 12 connected to the internal volume of the primary air duct 1 is installed on the primary air duct 1, and the annular cover 12 is located on the primary air duct 1 between the variable frequency discharge valve 11 and the air-assisting cylinder 2, and an inner ring plate 121 is fixedly embedded on the side of the annular cover 12 close to the air-assisting cylinder 2, and an air inlet pipe 13 is installed on the annular cover 12.

It should be noted that: the discharge port of the second discharge system in the CN117722694A patent is connected to the variable frequency discharge valve 11 on the primary air duct 1, and the discharge port of the primary air duct 1 is connected to the feed port of the boiler burner, and the air inlet pipe 13 is connected to the air supply pipe in the pneumatic conveying system. After the gas enters the air cylinder 2 through the air inlet pipe 13, the material falling from the variable frequency discharge valve 11 is blown to the burner.

In the embodiment of the utility model, referring to Figures 1 to 5, the air cannon assembly 3 for intermittently firing an air cannon for the primary air duct 1 is provided in the air assisting cylinder 2, and the air cannon assembly 3 includes an elastic pleated airbag 31, a front end surface of the elastic pleated airbag 31 is fixedly mounted with an electromagnetic exhaust valve 32, and a rear end of the elastic pleated airbag 31 is fixedly mounted with an air pressure plate 33, and a spring 34 elastically connected to the inner wall of the air assisting cylinder 2 is mounted on the air pressure plate 33, and one side of the spring 34 is fixedly mounted with an air pressure plate 33. The end of the air-assisting cylinder 2 is fixedly connected to the inner cylinder wall of the air-assisting cylinder 2, and the other end of the spring 34 is fixedly connected to the air compression plate 33. An air pump 35 is installed on the air-assisting cylinder 2, and the output end of the air pump 35 is connected to the air inlet of the elastic pleated airbag 31 through a conduit. The air-assisting cylinder 2 is fixedly embedded with an annular plate 21 near the cylinder mouth, and the inner plate wall of the annular plate 21 is fixedly connected to the bag wall of the elastic pleated airbag 31 on which an electromagnetic exhaust valve 32 is installed, and the electromagnetic exhaust valve 32 is located in the annular cavity of the annular plate 21.

It should be noted that: the air pump 35 is turned on to inflate the elastic pleated airbag 31. Since the front end surface of the elastic pleated airbag 31 is restricted by the annular plate 21, the elastic pleated airbag 31 abuts against the pressure plate 33 and compresses the spring 34 after inflation. After the elastic pleated airbag 31 expands to a predetermined degree, the electromagnetic exhaust valve 32 is opened. At this time, the elastic pleated airbag 31 is quickly exhausted and under the elastic force of the compression spring 34, the gas in the elastic pleated airbag 31 quickly rushes into the primary air duct 1. Then, the electromagnetic exhaust valve 32 is closed and the air pump 35 is turned on again for inflation. This reciprocating process cooperates with the gas in the pneumatic conveying system, so that there is a period of time when the airflow is enhanced in the primary air duct 1 at regular intervals to impact the material, which greatly suppresses the airflow caused by the high temperature at the burner port in the boiler and the backflow of hot air along the primary air duct, and eliminates the hidden danger of blockage or slow material dropping at the connection between the burner and the primary air duct of the boiler.

It should also be noted that the mouth of the air cylinder 2 is fixedly connected to one end of the primary air duct 1 via a flange, so as to facilitate the installation and removal of the air cylinder 2 .

The circuits and controls involved in the present invention are all prior art and will not be described in detail here.

The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims (7)

1. A closed-type conveying device for biomass fuel blending, characterized in that it comprises a primary air duct (1), an air-assisting cylinder (2) is installed on the primary air duct (1), and an air cannon assembly (3) for intermittently firing an air cannon for the primary air duct (1) is arranged in the air-assisting cylinder (2); The air gun assembly (3) comprises an elastic pleated airbag (31), a front end surface of the elastic pleated airbag (31) having an electromagnetic exhaust valve (32) fixedly mounted thereon, and a rear end of the elastic pleated airbag (31) having an air pressure plate (33) fixedly mounted thereon, the air pressure plate (33) having a spring (34) elastically connected to the inner wall of the air-assisting cylinder (2) mounted thereon, the air-assisting cylinder (2) having an air pump (35) mounted thereon, and the output end of the air pump (35) being connected to the air inlet of the elastic pleated airbag (31) via a conduit. 2. The closed conveying device for biomass fuel blending according to claim 1 is characterized in that an annular plate (21) is fixedly embedded near the cylinder mouth of the air-assisting cylinder (2), and the inner plate wall of the annular plate (21) is fixedly connected to the bag wall of the elastic pleated airbag (31) on which the electromagnetic exhaust valve (32) is installed, and the electromagnetic exhaust valve (32) is located in the annular cavity of the annular plate (21). 3. The closed biomass fuel blending and conveying device according to claim 2 is characterized in that one end of the spring (34) is fixedly connected to the inner cylinder wall of the air-assisting cylinder (2), and the other end of the spring (34) is fixedly connected to the air pressure plate (33). 4. The closed conveying device for biomass fuel blending according to claim 1, characterized in that the mouth of the air-assisting cylinder (2) is fixedly connected to one end of the primary air duct (1) through a flange. 5. The closed conveying device for biomass fuel blending according to claim 1, characterized in that a variable frequency discharge valve (11) is installed on one side of the primary air duct (1) close to the air cylinder (2). 6. The closed conveying device for biomass fuel blending according to claim 5 is characterized in that an annular cover (12) connected to the internal volume of the primary air duct (1) is installed on the primary air duct (1), and an inner ring plate (121) is fixedly embedded on the side of the annular cover (12) close to the air cylinder (2), and an air inlet pipe (13) is installed on the annular cover (12). 7. The closed biomass fuel blending and conveying device according to claim 6, characterized in that the annular cover (12) is located on the primary air duct (1) between the variable frequency discharge valve (11) and the air assist cylinder (2).