Multi-stage circulating steam boiler

Abstract

The utility model relates to the technical field of energy utilization, and provides a multi-stage circulation steam boiler which comprises a boiler shell, a heat preservation layer is fixedly connected to the top of the boiler shell, a smoke pipe is fixedly embedded in the inner surface of the heat preservation layer, a first fixing plate is fixedly connected to the bottom of the smoke pipe, a second fixing plate is fixedly connected to the top of the smoke pipe, and the second fixing plate is fixedly connected to the top of the boiler shell. A plurality of air holes are formed in the outer surfaces of the first fixing plate and the second fixing plate, a plurality of ascending pipes are fixedly connected to the outer surfaces of the opposite sides of the first fixing plate and the second fixing plate, and a smoke exhaust pipe is fixedly connected to the top of the second fixing plate, so that the combustion efficiency is improved, pollutant emission is reduced, the combustion time is prolonged, and the complete degree of combustion is improved; and meanwhile, the air gaps prevent heat transfer, the overall heat insulation effect is enhanced, heat dissipation losses are reduced, the descending pipes can absorb heat in the air gaps, and the heat energy utilization rate is further increased.

Description

Technical Field

[0001] This utility model relates to the field of energy utilization technology, and in particular to a multi-stage circulating steam boiler. Background Technology

[0002] Multi-stage circulating steam boilers improve thermal efficiency, enhance combustion performance, reduce pollutant emissions, and strengthen operational stability through the design of multiple circulation loops, while also optimizing system design.

[0003] While current technology offers many advantages, its disadvantages include the fact that some steam boilers use natural gas as fuel. The density difference between natural gas and air causes them to stratify and mix poorly upon entering the combustion chamber, leading to incomplete combustion. This incomplete combustion produces carbon monoxide, a toxic gas that endangers worker health, pollutes the environment, and reduces fuel efficiency. Furthermore, some steam boilers experience significant heat loss in their flue gas ducts, necessitating the addition of insulation. However, relying solely on insulation is problematic; once the insulation absorbs moisture, it fills the gaps, increasing thermal conductivity and reducing insulation effectiveness, further increasing heat loss and lowering energy efficiency. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a multi-stage circulating steam boiler to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model adopts the following technical solution: a multi-stage circulating steam boiler, comprising: a furnace shell, an insulation layer fixedly connected to the top of the furnace shell, a flue gas pipe fixedly embedded in the inner surface of the insulation layer, a fixing plate one fixedly connected to the bottom of the flue gas pipe, a fixing plate two fixedly connected to the top of the flue gas pipe, multiple air vents formed on the outer surfaces of both fixing plate one and fixing plate two, multiple riser pipes fixedly connected to the opposite outer surfaces of fixing plate one and fixing plate two, an exhaust pipe fixedly connected to the top of fixing plate two, and multiple return pipes fixedly connected to the outer surface of the exhaust pipe. A smoke collection box is fixedly connected to the bottom of multiple return smoke pipes. A return air fan is installed in the smoke collection box through an outlet pipe. A support plate is fixedly connected to the bottom of the return air fan. An air supply branch pipe is installed on the outer surface of the return air fan. An air supply main pipe is fixedly connected to the outer surface of the air supply branch pipe. A venturi tube is fixedly connected to the outer surface of the air supply main pipe. A gas pipe is installed at the bottom of the venturi tube. A combustion mechanism is installed on the inner surface of the furnace shell. A water supply mechanism is installed on the outer surface of the insulation layer. This improves combustion efficiency, reduces pollutant emissions, extends combustion time, improves the completeness of combustion, and thus improves energy utilization.

[0006] In a preferred embodiment, the water supply mechanism includes a water collection tank, which is fixedly connected to the outer surface of the insulation layer. A water supply pipe is fixedly connected to the outer surface of the water collection tank, and a downcomer is fixedly connected to the bottom of the water collection tank. The downcomer is fixedly connected to the outer surface of the first fixed plate, and a steam outlet pipe is fixedly connected to the outer surface of the second fixed plate. The air gap prevents heat transfer, enhances the overall heat insulation effect, and reduces heat loss. The downcomer can absorb heat in the air gap.

[0007] In a preferred embodiment, the combustion mechanism includes a flame converging hood, the top of which is fixedly connected to a flame guide tube, which can concentrate the flue gas into the flame guide tube.

[0008] In a preferred embodiment, the fixing plate is fixedly connected to the top of the furnace shell, the smoke collection box and the support plate are fixedly connected to the outer surface of the furnace shell, the inner surfaces of the flue pipe, the exhaust pipe and the flame guide pipe are all provided with spiral grooves, and the support plate can support the return air fan.

[0009] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0010] 1. This utility model utilizes a venturi tube to increase the collision frequency between air and gas molecules, allowing the air and gas to mix thoroughly in high-speed flow, thereby improving combustion efficiency and reducing pollutant emissions. In addition, the spiral groove in the flame guide tube extends the combustion time and improves the completeness of combustion. Finally, in conjunction with the return smoke fan, some of the unburned particles are sent into the fresh air to mix with the air and increase the temperature of the fresh air, thereby improving energy utilization.

[0011] 2. This utility model utilizes air gaps to prevent heat transfer, thereby enhancing the overall heat insulation effect and reducing heat loss. The downcomer can absorb heat from the air gaps, further improving the utilization rate of thermal energy. Attached Figure Description

[0012] Figure 1 A schematic diagram of the main structure of a multi-stage circulating steam boiler provided by this utility model;

[0013] Figure 2 A schematic diagram of the flame converging hood position structure of a multi-stage circulating steam boiler provided by this utility model;

[0014] Figure 3 A schematic diagram of the spiral groove position structure of a multi-stage circulating steam boiler provided by this utility model;

[0015] Figure 4 This is a partial exploded structural diagram of a multi-stage circulating steam boiler provided by this utility model.

[0016] Legend:

[0017] 1. Furnace shell; 2. Insulation layer; 3. Flue gas pipe; 4. Fixing plate one; 5. Fixing plate two; 6. Ascending pipe; 7. Downsink pipe; 8. Water collection box; 9. Water supply pipe; 10. Steam outlet pipe; 11. Vent hole; 12. Exhaust pipe; 13. Spiral groove; 14. Flame concentrator; 15. Venturi tube; 16. Main air supply pipe; 17. Gas pipe; 18. Support plate; 19. Flame guide pipe; 20. Branch air supply pipe; 21. Return smoke pipe; 22. Smoke collection box; 23. Return air fan. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-4 This utility model provides a technical solution: a multi-stage circulating steam boiler, comprising: a furnace shell 1, an insulation layer 2 fixedly connected to the top of the furnace shell 1, a flue gas pipe 3 fixedly embedded on the inner surface of the insulation layer 2, a fixing plate 4 fixedly connected to the bottom of the flue gas pipe 3, a fixing plate 5 fixedly connected to the top of the flue gas pipe 3, multiple vent holes 11 opened on the outer surfaces of both the fixing plate 4 and the fixing plate 5, multiple riser pipes 6 fixedly connected to the opposite outer surfaces of the fixing plate 4 and the fixing plate 5, an exhaust pipe 12 fixedly connected to the top of the fixing plate 5, and multiple return pipes 21 fixedly connected to the outer surface of the exhaust pipe 12. A smoke collection box 22 is fixedly connected to the bottom of the furnace. A return air fan 23 is installed in the smoke collection box 22 through the outlet pipe. A support plate 18 is fixedly connected to the bottom of the return air fan 23. An air supply branch pipe 20 is installed on the outer surface of the return air fan 23. An air supply main pipe 16 is fixedly connected to the outer surface of the air supply branch pipe 20. A venturi pipe 15 is fixedly connected to the outer surface of the air supply main pipe 16. A gas pipe 17 is installed at the bottom of the venturi pipe 15. A combustion mechanism is installed on the inner surface of the furnace shell 1. A water supply mechanism is installed on the outer surface of the insulation layer 2. This improves combustion efficiency, reduces pollutant emissions, extends combustion time, and improves the completeness of combustion, thereby improving energy utilization.

[0020] like Figure 4As shown, the water supply mechanism includes a water collection tank 8, which is fixedly connected to the outer surface of the insulation layer 2. A water supply pipe 9 is fixedly connected to the outer surface of the water collection tank 8, and a downcomer 7 is fixedly connected to the bottom of the water collection tank 8. The downcomer 7 is fixedly connected to the outer surface of the first fixing plate 4, and a steam outlet pipe 10 is fixedly connected to the outer surface of the second fixing plate 5. The air gap prevents the transfer of heat, enhances the overall heat insulation effect, and reduces heat loss. The downcomer 7 can absorb the heat in the air gap, further improving the utilization rate of thermal energy.

[0021] like Figure 3 As shown, the combustion mechanism includes a flame concentrator 14, and a flame guide tube 19 is fixedly connected to the top of the flame concentrator 14. The flame concentrator 14 can concentrate the flue gas into the flame guide tube 19, laying the foundation for the formation of a spiral airflow in the flame guide tube 19.

[0022] like Figure 1-4 As shown, the fixing plate 4 is fixedly connected to the top of the furnace shell 1, the smoke collection box 22 and the support plate 18 are fixedly connected to the outer surface of the furnace shell 1, the inner surfaces of the flue gas pipe 3, the exhaust pipe 12 and the flame guide pipe 19 are all provided with spiral grooves 13, and the support plate 18 can support the return air fan 23, providing a good working environment for the return air fan 23.

[0023] Working Principle: This equipment is a multi-stage circulating steam boiler. During operation, the water supply pipe 9 is connected to the feedwater pipeline, allowing feedwater to enter the water collection tank 8, and then through the downcomer 7 into the fixed plate 4. The boiler is then started, and the gas pipe 17 is connected to the gas header, and the air supply header 16 is connected to the blower. External air and gas enter the venturi tube 15 together. In the contraction section of the venturi tube 15, the velocity of the external air and gas increases, and the static pressure decreases. At the throat, the velocity reaches its maximum, and the static pressure is at its lowest, creating a vortex effect that promotes rapid mixing of air and gas. Subsequently, in the diffusion section, the velocity decreases, and the static pressure recovers, further consolidating the mixing effect, ensuring the air and gas... The gas and air are thoroughly mixed in high-speed flow. The mixed gas and air enter the interior of the furnace shell 1 and are ignited by an electronic igniter. The electronic igniter is an existing structure and will not be described in detail. The gas and air then burn inside the furnace shell 1. Subsequently, the hot air rises to form flue gas. The flue gas is then gathered by the flame concentrator 14 and enters the flame guide tube 19, where the velocity of the flue gas reaches its maximum. Due to the spiral groove 13 inside the flame guide tube 19, the flue gas moves in a spiral motion. This motion can prolong the combustion time and improve the completeness of combustion. After the flue gas leaves the flame guide tube 19, it enters the upper part of the furnace shell 1, where the flue gas loss is reduced, resulting in a more uniform temperature distribution in the upper part of the furnace shell 1.

[0024] Then, the water inside the fixed plate 4 absorbs the heat inside the furnace shell 1, causing the water to form steam. Utilizing the density difference, the steam enters the riser pipe 6. The flue gas enters the flue gas pipe 3 through the vent hole 11 on the fixed plate 4. The spiral groove 13 in the flue gas pipe 3 can form a vortex in the flue gas, increasing the contact time between the flue gas and the riser pipe 6, improving the heat exchange efficiency, and continuing to heat the steam inside the riser pipe 6. Then, the steam is led out through the steam outlet pipe 10 through the fixed plate 2 5, and the flue gas enters the exhaust pipe 12 through the vent hole 11 on the fixed plate 2 5, and then is discharged.

[0025] The spiral groove 13 in the flue gas pipe 12 can create a vortex inside the flue gas pipe 12. At this time, the unburned particles will move towards the return flue gas pipes 21 on both sides due to the effect of the vortex. Then, the return air fan 23 on the support plate 18 is started. The return air fan 23 is equipped with a frequency converter cabinet and can adjust the frequency. The return air fan 23 will create a negative pressure inside the smoke collection box 22, and then the return flue gas pipe 21 will also be under negative pressure. As a result, the unburned particles will be driven by the flue gas to the smoke collection box 22 through the return flue gas pipe 21. Then, the return air fan 23 will apply power to make the flue gas enter the main air supply pipe 16 through the air supply branch pipe 20 to heat the fresh air, increase the initial temperature of the fresh air, reduce the impact of the fresh air on the internal temperature of the furnace shell 1, and the unburned particles will also return to the furnace shell 1 for combustion, protecting the environment and improving the energy utilization rate.

[0026] The insulation shell 2 is made of glass wool, while the flue pipe 3 is covered with mineral wool. Between the mineral wool and glass wool is the downcomer 7 and an air gap. The air gap has a low thermal conductivity, which can prevent heat transfer to a certain extent and enhance the overall insulation effect. At the same time, the air gap provides a buffer for water vapor, making it difficult for water vapor to directly contact the mineral wool on the flue pipe 3, keeping the mineral wool dry and extending the service life of the insulation system. The downcomer 7 is located between the two insulation layers and can further absorb the temperature in the air gap, reducing heat loss and improving energy utilization.

[0027] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A multi-stage circulating steam boiler, comprising: A furnace shell (1) is characterized in that: a heat insulation layer (2) is fixedly connected to the top of the furnace shell (1), a flue gas pipe (3) is fixedly embedded on the inner surface of the heat insulation layer (2), a fixing plate (4) is fixedly connected to the bottom of the flue gas pipe (3), a fixing plate (5) is fixedly connected to the top of the flue gas pipe (3), a plurality of ventilation holes (11) are opened on the outer surfaces of the fixing plate (4) and the fixing plate (5), a plurality of riser pipes (6) are fixedly connected to the opposite outer surfaces of the fixing plate (4) and the fixing plate (5), a smoke exhaust pipe (12) is fixedly connected to the top of the fixing plate (5), and a plurality of return smoke pipes (12) are fixedly connected to the outer surface of the smoke exhaust pipe (12). The bottom of the multiple return smoke pipes (21) is fixedly connected to a smoke collection box (22). The smoke collection box (22) is equipped with a return air fan (23) through an outlet pipe. The bottom of the return air fan (23) is fixedly connected to a support plate (18). The outer surface of the return air fan (23) is provided with an air supply branch pipe (20). The outer surface of the air supply branch pipe (20) is fixedly connected to an air supply main pipe (16). The outer surface of the air supply main pipe (16) is fixedly connected to a venturi tube (15). The bottom of the venturi tube (15) is provided with a gas pipe (17). The inner surface of the furnace shell (1) is provided with a combustion mechanism. The outer surface of the insulation layer (2) is provided with a water supply mechanism.

2. The multi-stage circulating steam boiler according to claim 1, characterized in that: The water supply mechanism includes a water collection tank (8), which is fixedly connected to the outer surface of the insulation layer (2). A water supply pipe (9) is fixedly connected to the outer surface of the water collection tank (8). A downcomer (7) is fixedly connected to the bottom of the water collection tank (8). The downcomer (7) is fixedly connected to the outer surface of the first fixing plate (4). A steam outlet pipe (10) is fixedly connected to the outer surface of the second fixing plate (5).

3. A multi-stage circulating steam boiler according to claim 1, characterized in that: The combustion mechanism includes a flame concentrator (14), and a flame guide tube (19) is fixedly connected to the top of the flame concentrator (14).

4. A multi-stage circulating steam boiler according to claim 3, characterized in that: The fixing plate (4) is fixedly connected to the top of the furnace shell (1), the smoke collection box (22) and the support plate (18) are fixedly connected to the outer surface of the furnace shell (1), and the inner surfaces of the flue gas pipe (3), the exhaust pipe (12) and the flame guide pipe (19) are all provided with spiral grooves (13).

Images