Exhaust treatment system

Abstract

This invention provides an exhaust gas treatment system that eliminates the need for filters such as the filter cloth in a bag filter system, thereby significantly reducing the time and effort required for maintenance. [Solution] The present invention relates to an exhaust treatment device for removing dust contained in an airflow, wherein a diameter-reducing section 14 is formed in the airflow path, reducing the cross-sectional area of ​​the flow path via a diffuser section 13, a blower fan 15 is installed on the upstream side of the diameter-reducing section 14 to send the airflow downstream, a turbine 16 is arranged coaxially with the blower fan 15 on the downstream side of the diameter-reducing section 14 to recover exhaust energy, a combustion chamber 17 is formed between the blower fan 15 and the turbine 16, and an ignition torch 21 is placed in the combustion chamber 17.

Description

Technical Field

[0001] The present invention relates to an exhaust gas treatment device for removing dust contained in an air flow.

Background Art

[0002] As an unloader for unloading various bulk goods such as grains loaded on a ship moored at a quay, a pneumatic unloader is known that performs unloading by inserting a suction nozzle into the bulk goods to be handled and sucking them (see, for example, Patent Documents 1 and Patent Documents 2).

[0003] As shown in FIG. 3, this type of pneumatic unloader 1 includes a receiver tank 3 into which bulk goods 2 can be introduced, a vacuum blower 5 connected to the receiver tank 3 via an air pipe 4, a horizontal telescopic pipe 6 swingably connected to the receiver tank 3 and extending horizontally, a bend pipe 7 connected to the tip of the horizontal telescopic pipe 6 and bent downward, a vertical telescopic pipe 8 connected to the tip of the bend pipe 7 and extending vertically downward substantially, and a suction nozzle 9 connected to the tip of the vertical telescopic pipe 8 and inserted into the bulk goods loaded on a ship (not shown) to a predetermined depth.

[0004] Here, the horizontal telescopic pipe 6 includes a large-diameter pipe portion 6a connected to the receiver tank 3 and a small-diameter pipe portion 6b slidably inserted into the large-diameter pipe portion 6a, and is configured to be telescopic by relatively moving the large-diameter pipe portion 6a and the small-diameter pipe portion 6b.

[0005] Further, the vertical telescopic pipe 8 includes a large-diameter pipe portion 8a and a small-diameter pipe portion 8b slidably inserted into the large-diameter pipe portion 8a, and is configured to be telescopic by relatively moving the large-diameter pipe portion 8a and the small-diameter pipe portion 8b.

[0006] The bulk material 2, which is the cargo (object to be conveyed), is then sucked into the suction nozzle 9 along with air, and introduced into the receiver tank 3 via the vertical telescopic pipe 8, the bend pipe 7, and the horizontal telescopic pipe 6. The bulk material 2 separated from the air by the receiver tank 3 is then supplied to the chain conveyor 10. Meanwhile, the air separated from the bulk material 2 passes through the filter cloth 12 in the bag filter device 11 at the top of the receiver tank 3 to remove dust, and is then sucked into the vacuum blower 5 via the air pipe 4. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2016-23001 [Patent Document 2] Japanese Patent Publication No. 2016-23004 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, because the filter cloth 12 of the bag filter device 11 becomes clogged in a short period of time, maintenance must be performed frequently in short cycles to remove dust from the filter cloth 12 and clear the clogging, which presents a challenge as it requires a great deal of effort and time for this maintenance.

[0009] This invention was made in view of the above-mentioned problems, and provides an exhaust gas treatment device that eliminates the need for filters such as the filter cloth of a bag filter device, thereby significantly reducing the effort and time required for maintenance. [Means for solving the problem]

[0010] The present invention relates to an exhaust treatment apparatus for removing dust contained in an airflow, characterized in that a diameter-reducing section is formed in the airflow path, reducing the cross-sectional area of ​​the flow path via a diffuser section; a blower fan is installed on the upstream side of the diameter-reducing section to send the airflow downstream; a turbine for recovering exhaust energy is arranged coaxially with the blower fan on the downstream side of the diameter-reducing section; a combustion chamber is formed between the blower fan and the turbine; and an ignition torch is placed inside the combustion chamber.

[0011] In this configuration, the blower fan drives out an airflow, which flows into the narrowed section, reducing the cross-sectional area of ​​the flow path and increasing the flow velocity. When the dust in the airflow is ignited with an ignition torch in this state, heat is transmitted to other dust particles in a chain reaction, causing them to burn and the dust in the airflow to be completely burned within the combustion chamber.

[0012] In this case, the airflow, which is heated and pressurized by the combustion of dust in the combustion chamber, expands and flows downstream, driving a turbine to recover exhaust energy. This turbine then drives the blower fan with minimal power. If the blower fan can be driven solely by the recovery of exhaust energy by the turbine, the power supply to the blower fan may be stopped, or it may be continued to ensure stable operation. Furthermore, the increased airflow velocity suppresses heat transfer upstream of the combustion chamber, preventing the dust from spreading upstream, and the dust is incinerated only within the combustion chamber. If combustion continues using dust as a fuel source, the combustion assistance by the ignition torch may be stopped, or it may be continued to ensure stable combustion.

[0013] Furthermore, in implementing the present invention more concretely, it is preferable to include a control device that controls the blower fan to maintain a predetermined rotational speed at all times. Additionally, it is possible to add an extension fan to the diffuser section, which is driven coaxially with the blower fan to send the airflow downstream, or to employ an ignition torch equipped with a gas introduction pipe and an ignition plug for adding a flammable gas to the airflow.

[0014] Furthermore, in specifically applying the present invention, for example, it can be applied to the receiver tank of a pneumatic unloader and used as an exhaust treatment device to remove dust contained in the air separated from the bulk material in the receiver tank. [Effects of the Invention]

[0015] According to the exhaust gas treatment device of the present invention, the ignition torch in the combustion chamber ignites dust particles in the airflow, and the heat is transferred in a chain reaction to other dust particles, causing combustion. As a result, the dust in the airflow can be completely burned, eliminating the need for filters such as the filter cloth in conventional bag filter devices. This significantly reduces the effort and time required for maintenance. Furthermore, by driving a blower fan while recovering exhaust energy with a turbine, it is possible to achieve operation with significantly reduced running costs, among other excellent effects. [Brief explanation of the drawing]

[0016] [Figure 1] This is a partially cutaway cross-sectional view showing one embodiment of the exhaust gas treatment apparatus of the present invention. [Figure 2] This is a magnified view showing the details of the ignition torch in Figure 1. [Figure 3] This is an overall diagram showing an example of a typical pneumatic unloader. [Modes for carrying out the invention]

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] FIG. 1 shows an embodiment of the exhaust gas treatment device of the present invention. In this embodiment, the case where it is applied to the receiver tank 3 in the pneumatic unloader 1 described in FIG. 3 above is exemplified. Instead of the bag filter device installed on the upper part of the receiver tank 3, a diameter-reducing portion 14 that reduces the flow path cross-sectional area via the diffuser portion 13 is formed at the upper part of the receiver tank 3, and a blower fan 15 that sends the airflow to the downstream side is installed on the upstream side in the diameter-reducing portion 14. Furthermore, an expansion fan 22 that is driven coaxially with the blower fan 15 and sends the airflow to the downstream side is added to the diffuser portion 13.

[0019] Also, on the downstream side in the diameter-reducing portion 14, a turbine 16 that recovers exhaust energy is arranged coaxially with the blower fan 15, and a combustion chamber 17 is formed between the blower fan 15 and the turbine 16. Inside the combustion chamber 17, as shown enlarged in FIG. 2, an ignition torch 21 including a gas introduction pipe 19 that adds combustible gas 18 to the airflow and an ignition plug 20 is installed, and the ignition plug 20 can ignite the combustible gas 18 introduced through the gas introduction pipe 19.

[0020] Here, the above-described blower fan 15, expansion fan 22, and turbine 16 are composed of a rod-shaped body portion 24 supported along the central axis of the diameter-reducing portion 14 and the diffuser portion 13 by a plurality of supports 23, blower blades 25, 26 and turbine blades 27 rotatably provided in a plurality of stages in the height direction of the body portion 24, and an electric motor 28 built in the body portion 24. The electric motor 28 rotates and drives the blower blades 25, 26 in each stage.

[0021] Also, power is supplied to the electric motor 28 from a power source 29 via an inverter 30, and the control device 31 executes control to always maintain a predetermined rotational speed of the blower fan 15 (and the expansion fan 22) with respect to the inverter 30.

[0022] Reference numeral 32 in Fig. 1 is an emergency shutter which is configured such that, in an emergency, the stopper function is released and the inlet of the reduced-diameter portion 14 can be instantaneously blocked by the elastic force of the elastic body 33.

[0023] Thus, when configured in this way, the bulk material 2 is introduced into the receiver tank 3 through the horizontal expansion and contraction pipe 6. The receiver tank 3 separates the bulk material 2 from the air and discharges it downward. On the other hand, the air separated from the bulk material 2 is sent upward together with the dust by the blower fan 15 and the expansion fan 22, flows into the reduced-diameter portion 14 through the diffuser portion 13, and the flow velocity is increased by narrowing the cross-sectional area of the flow path here. However, when the dust in the air flow is ignited by the ignition torch 21 in such a state, heat is propagated to the other dust particles in a chain reaction and combustion occurs, and the dust in the air flow is completely burned in the combustion chamber 17.

[0024] At this time, the air flow whose temperature has risen and pressure has increased due to the combustion of the dust in the combustion chamber 17 drives the turbine 16 while expanding toward the downstream side and the exhaust energy is recovered. By driving the turbine 16, the blower fan 15 (and the expansion fan 22) is driven with less power. However, if the exhaust energy recovery by the turbine 16 alone can continue to drive the blower fan 15 (and the expansion fan 22), the power supply to the blower fan 15 (and the expansion fan 22) may be stopped, or the power supply may be continued to maintain stable driving.

[0025] In addition, since the flow velocity of the air flow is increased, the propagation of heat to the upstream side of the combustion chamber 17 is suppressed and the spread of the dust combustion to the upstream side of the combustion chamber 17 is prevented, and the dust is incinerated only in the combustion chamber 17. Here, if the combustion can continue with the dust as the fuel source, the combustion assistance by the ignition torch 21 may be stopped, or the combustion assistance by the ignition torch 21 may be continued to maintain stable combustion.

[0026] Furthermore, when stopping operation, a suction nozzle (not shown in the illustration, see suction nozzle 9 in Figure 3) is lifted from the bulk material 2 to interrupt the lifting of the bulk material 2, and the operation of the blower fan 15 is stopped after the dust in the airflow has been removed, thereby ensuring a safe shutdown.

[0027] Therefore, according to the above embodiment, the ignition torch 21 in the combustion chamber 17 ignites the dust in the airflow, and the heat is transferred in a chain reaction to other dust particles, causing combustion. As a result, the dust in the airflow can be completely burned, eliminating the need for filters such as the filter cloth in conventional bag filter devices. This significantly reduces the effort and time required for maintenance. Furthermore, by driving the blower fan 15 while recovering exhaust energy with the turbine 16, it is possible to achieve operation with significantly reduced running costs.

[0028] Furthermore, as illustrated in this embodiment, when applied to the receiver tank 3 of a pneumatic unloader, it can replace the conventional equipment that runs from the bag filter device at the top of the receiver tank through an air pipe to a vacuum blower.

[0029] Furthermore, the exhaust treatment device of the present invention is not limited to the embodiments described above. Although the illustrated example shows an application to the receiver tank of a pneumatic unloader, it can be applied in place of dust collectors used in various facilities, and various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0030] 1. Pneumatic Unloader 3 Receiver Tank 13 Diffuser section 14 Reduced diameter part 15. Blower fan 16 Turbine 17 Combustion chamber 18. Flammable gases 19 Gas inlet pipe 20 Spark plugs 21 Ignition Torch 22 Expansion Fans 31 Control device

Claims

1. An exhaust treatment device for removing dust contained in an airflow, wherein a diameter-reducing section is formed in the airflow path, reducing the cross-sectional area of ​​the flow path via a diffuser section, a blower fan is installed on the upstream side of the diameter-reducing section to send the airflow downstream, a turbine for recovering exhaust energy is arranged coaxially with the blower fan on the downstream side of the diameter-reducing section, a combustion chamber is formed between the blower fan and the turbine, and an ignition torch is placed in the combustion chamber.

2. The exhaust treatment apparatus according to claim 1, further comprising a control device that controls the blower fan to maintain a predetermined rotational speed at all times.

3. The exhaust treatment apparatus according to claim 1 or 2, wherein an extension fan is added to the diffuser section, which is driven coaxially with the blower fan to send the airflow downstream.

4. The exhaust treatment apparatus according to claim 1 or 2, wherein the ignition torch comprises a gas introduction pipe for adding a combustible gas to the airflow and an ignition plug.

5. The exhaust treatment apparatus according to claim 1 or 2, applied to the receiver tank of a pneumatic unloader.

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