Multi-pass returner

Abstract

The utility model relates to circulating fluidized bed boiler technical field discloses a kind of multi-pass return material device, including descending pipeline, valve body, discharge pipeline connected in turn, discharge pipeline includes ascending section and discharge section, and valve body bottom is provided with air distribution plate, descending pipeline is set to multiple, and the discharge port of descending pipeline is connected with valve body inlet port. By setting multiple descending pipelines for feeding, the originally multiple return material devices can be combined into one, which greatly optimizes the circulating fluidized bed boiler system, makes the structure more efficient and simple, and solves the technical problem that the existing return material device cannot adapt to the circulating fluidized bed boiler system under complex working conditions.

Description

Technical Field

[0001] This utility model relates to the field of circulating fluidized bed boiler technology, specifically a multi-channel return feeder for circulating fluidized beds. Background Technology

[0002] Circulating fluidized bed (CFB) technology is a clean coal combustion technology. Its basic working principle is that solid materials are fluidized and burned in the furnace. The resulting flue gas undergoes gas-solid separation via a cyclone separator, and fine particulate matter in the flue gas is returned to the furnace through a return feeder. The furnace, cyclone separator, and return feeder constitute the main circulation loop of the CFB boiler. Figure 1 As shown, existing circulating fluidized bed boiler feeders typically have one material inlet corresponding to one or more material outlets. However, with the continuous expansion of fluidized bed technology applications, multiple material feeders are often required in engineering projects. If a feeder is set up for each material feeder, multiple feeders need to be arranged, making the entire circulating fluidized bed boiler system too complex and making the layout, installation, and subsequent maintenance very difficult.

[0003] Existing technology, patent application number CN202123347518.7, entitled "A Circulating Fluidized Bed Return Feeder," discloses a circulating fluidized bed return feeder, including a downcomer, a horizontal section, an ascending section, and return legs. The top of the horizontal section protrudes into the channel, forming a transversely turning channel structure. This utility model patent discloses a return feeder with only one inlet, which is unsuitable for material transport in complex circulating fluidized bed boiler systems. Utility Model Content

[0004] In order to solve the technical problem that existing feeders cannot adapt to complex working conditions with multiple materials, this utility model proposes a feeder for circulating fluidized beds.

[0005] The multi-channel return feeder includes a downcomer pipe, a valve body, and a discharge pipe connected in sequence. The discharge pipe includes an ascending section and a discharge section. An air distribution plate is provided at the bottom of the valve body. The downcomer pipe is configured as a plurality of pipes, and the discharge port of each downcomer pipe is connected to the inlet of the valve body.

[0006] The above-mentioned multi-channel return feeder has multiple discharge pipes.

[0007] The beneficial effects of this utility model include: by setting up multiple feed downpipes, the materials and pipes that originally required multiple return feeders can be combined into one, which greatly optimizes the circulating fluidized bed boiler system, making its structure more efficient and simple, and solving the technical problem that the return feeders in the prior art cannot adapt to the circulating fluidized bed boiler system under complex working conditions. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view of a conventional feeder structure in the prior art.

[0009] Figure 2 This is a top view of a conventional feeder in the prior art.

[0010] Figure 3 This is a front view of Embodiment 1 of the multi-channel return feeder of this utility model.

[0011] Figure 4 This is a top view of Embodiment 1 of the multi-channel return feeder of this utility model.

[0012] Figure 5 This is a front view of Embodiment 2 of the multi-channel return feeder of this utility model.

[0013] Figure 6 This is a top view of Embodiment 2 of the multi-channel return feeder of this utility model.

[0014] Figure 7 This is a side view of Embodiment 2 of the multi-channel return feeder of this utility model.

[0015] The diagram is labeled as follows: 1-downward pipe, 2-valve body, 21-air distribution plate, 3-discharge pipe, 31-ascending section, 32-discharge section. Detailed Implementation

[0016] The present invention will now be described in conjunction with the accompanying drawings. Example 1

[0017] like Figures 2-4 This utility model is a multi-channel return feeder, which includes a downcomer pipe 1, a valve body 2, and a discharge pipe 3 connected in sequence. The discharge pipe 3 includes an ascending section 31 and a discharge section 32. The bottom of the valve body 2 is provided with an air distribution plate 21. High-pressure fluidizing air is introduced into the bottom of the valve body 2 through the air distribution plate 21. Under the action of the high-pressure fluidizing air, the material in the valve body is in a fluidized state. After overcoming the action of gravity, it flows out through the ascending section 31 and the discharge section 32. In this embodiment, there are 3 downcomer pipes 1, and the discharge ports of the downcomer pipes 1 are all connected to the inlet ports of the valve body 2.

[0018] In actual use, the multi-channel return feeder described in this embodiment allows three streams of material to flow into the valve body 2 through three different descending pipes 1 under the action of gravity. High-pressure fluidizing air is introduced into the bottom of the valve body 2 through the air distribution plate 21. Under the action of the high-pressure fluidizing air, the material flows out through the rising section 31 and the discharge section 32, thus completing the return of the material. Example 2

[0019] Furthermore, such as Figures 5-7As shown, based on the multi-channel return feeder described in Example 1, three downcomer pipes 1 are labeled A, B, and C, and three discharge pipes 3 are set up and labeled a, b, and c respectively. Fluidizing air at different pressures can be introduced into different areas of the air distribution plate 21. Combined with the control of the material feed rate per unit time in different downcomer pipes 1, the overall air distribution uniformity of the valve body 2 can be controlled. For example, if it is necessary to increase the discharge rate of discharge pipe a, the pressure of the fluidizing air introduced into the air distribution plate 21 between downcomer pipe A and discharge pipe 3a can be increased, and the feed rate of downcomer pipe 1 per unit time can be increased, ultimately achieving the goal of increasing the discharge rate of discharge pipe a. The same applies to discharge pipes B and C. The same or different types of materials can be introduced into different downcomer pipes 1. After the materials are uniformly mixed in the valve body 2, they flow out through different discharge pipes 3. The discharge rate in each discharge pipe 3 can be controlled to a certain extent by controlling the fluidizing air pressure in different areas of the air distribution plate 21.

[0020] In practical use, the multi-channel return feeder described in this embodiment allows three streams of the same or different types of materials to flow through three different downcomer pipes 1 and enter the valve body 2 under the action of gravity. Under the action of high-pressure fluidizing air introduced through the air distribution plate 21, the three streams of materials flow out through the discharge pipes 3 connected to the three downcomer pipes 1. Furthermore, by introducing fluidizing air at different pressures into different areas of the air distribution plate 21, the flow rate of the materials can be controlled in zones to improve the uniformity of fluidization.

[0021] Compared with the prior art, the multi-channel return feeder provided by this utility model, by setting multiple downflow pipes 1 and connecting them to the corresponding discharge pipes 3 via valve bodies 2, can achieve precise control of the flow path of multiple materials of the same or different types using a single return feeder. Furthermore, it can adopt a fluidizing air zoning control method with different pressures to improve fluidization uniformity, thus solving the technical problem that the return feeders in the prior art cannot adapt to the complex working conditions of the circulating fluidized bed boiler system.

Claims

1. A multi-channel return feeder, comprising a downcomer pipe (1), a valve body (2), and a discharge pipe (3) connected in sequence, wherein the discharge pipe (3) includes an upcomer section (31) and a discharge section (32), and the valve body (2) is provided with an air distribution plate (21) at its bottom, characterized in that: The descending pipe (1) is configured as a plurality of pipes, and the outlet of each descending pipe (1) is connected to the inlet of the valve body (2).

2. The multi-channel return feeder according to claim 1, characterized in that: The discharge pipes (3) are configured in multiples.

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