A pneumatic conveying switching system and its control method

Abstract

A pneumatic conveying switching system and its control method, the system includes several original conveying pipelines connected to the original drop point, each original conveying pipeline is provided with a three-way joint, and a switching pipeline is led out through the three-way joint. Several switching pipelines are merged into one pipeline through a pipeline distributor, and the merged pipeline is connected to an air-material mixer, and the air-material mixer is connected to an air-supply device, and the outlet of the air-material mixer is connected to a double sleeve, and the double sleeve is connected to the new drop point. The control method includes setting a double sleeve of corresponding diameter according to the situation of the new drop point; when the conveying distance is not more than 800m, the pressure gas of the air-supply device is drawn from the original compressed air system; during operation, only one of the original conveying pipeline and its corresponding switching pipeline is opened at the same time. The present invention can ensure that the original conveying system delivers to the original drop point, and can also ensure that the new conveying system delivers to the new drop point, and can make the new and old storage systems serve as backup for each other.

Description

Technical Field

[0001] The present invention belongs to the field of pneumatic solid two-phase flow transportation, and particularly relates to a pneumatic transportation switching system and its control method, which are particularly applicable to granular materials such as fly ash from thermal power plants or coal-fired boiler power stations, power workshops, as well as grains and cement. It is used when the destination address of pneumatic transportation needs to be changed or a new storage warehouse needs to be added. Background Art

[0002] Currently, many domestic thermal power plants have built large steel plate storage warehouses for fly ash storage and comprehensive utilization in order to meet the national standard of zero fly ash emissions, or plan to transport fly ash to nearby cement plants.

[0003] For the increase or change of the fly ash transportation destination, the traditional coping method is to build a complete set of pneumatic ash removal transportation system and compressed air system under the original destination (such as under the warehouse). However, the costs of land use, design, investment, and construction are relatively high, the construction period is long, and the operating power consumption is greatly increased due to the newly added air compressor system. For example, for a newly added pneumatic transportation system with an output of 100 t / h and a transportation distance of 800 m, at least 3 air compressors need to be added, with a cost of about 1.2 million yuan and an operating power of at least 500 KW. In addition, drying devices, gas storage tanks, pneumatic transportation equipment, and supporting valves, etc. also need to be added.

[0004] Therefore, there is an urgent need to study a reliable, efficient, energy-saving, and economical solution to solve this problem. Summary of the Invention

[0005] Aiming at the problem in the above-mentioned existing technology that the original transportation system becomes inapplicable due to the change of the transportation destination, the present invention provides a pneumatic transportation switching system and its control method, which can not only ensure the process requirements of the original transportation system for transporting to the original warehouse, but also ensure the process requirements of the new transportation system for transporting to the newly added destination, and can operate complementarily, being economical and reliable.

[0006] In order to achieve the above object, the present invention has the following technical solutions:

[0007] A pneumatic transportation switching system includes several original transportation pipelines connected to the original feeding point. A three-way joint is provided on each original transportation pipeline, and a switching pipeline is led out through the three-way joint. Several switching pipelines are merged into one pipeline through a pipeline distributor, and the merged pipeline is connected to an air-material mixer. A supplementary air device is connected to the air-material mixer, and the outlet of the air-material mixer is connected to a double sleeve pipe, which is connected to the new feeding point.

[0008] Preferably, one output end of the three-way joint is horizontally arranged, and the other output end is vertically arranged, and the switching pipeline is connected to the vertically arranged output end.

[0009] Preferably, the two output ends of the three-way connector are each connected to a pneumatic valve, and the two pneumatic valves are locked to each other, and only one of them can be opened at the same time.

[0010] Preferably, the three-way joint, pneumatic valve, pipeline distributor and gas-material mixer are connected to the pipeline respectively by flanges.

[0011] Preferably, the switching pipes of two adjacent original conveying pipes are merged into one pipe through a pipe distributor; one input end of the pipe distributor is horizontally set, the other input end is vertically set, and the output end is horizontally set, wherein the vertically set input end is directly connected to the corresponding switching pipe, and the horizontally set input end is connected to the corresponding switching pipe through an elbow.

[0012] Preferably, the double-tube is composed of two layers of inner and outer pipes, and the inner pipe is provided with a plurality of cutouts for circulating compressed air.

[0013] Preferably, the average material-gas ratio in the double tube is not less than 30 kg / kg; the terminal velocity of the double tube is 12 m / s-14 m / s; and the pipe wall thickness of the double tube is not less than 7 mm.

[0014] Preferably, the air supply device includes a branch pipe connected to the compressed air main pipe, the branch pipe is provided with a main line and a bypass pipe connected in parallel, the main line and the bypass pipe are both provided with a pneumatic shut-off valve, a throttle orifice plate and a regulating valve, and a check valve is also provided on the main line outside the bypass pipe, and the main line and the bypass pipe share the check valve;

[0015] The air supply device on each gas-material mixer is independently set and connected to the compressed air main pipe. The compressed air main pipe is provided with a manual shut-off valve in front of the air supply device connection position; a pressure transmitter is provided on the double casing.

[0016] Preferably, the switching pipelines are all led upward through three-way joints, the air supply devices are all arranged above the gas-material mixer, and the compressed air main pipe is arranged above all the air supply devices; a working platform for maintenance is set between the double casing and the original conveying pipeline.

[0017] The present invention also provides a control method for the pneumatic conveying switching system, comprising:

[0018] Set up double sleeves of corresponding diameters according to the new blanking point;

[0019] When the conveying distance is not more than 800m, the pressure gas of the air supply device is drawn from the original compressed air system;

[0020] During operation, only one of the original conveying pipeline and its corresponding switching pipeline is opened at the same time.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The pneumatic conveying switching system of the present invention can be built on the original conveying system, with less investment, quick results, convenient use, stable operation, less maintenance work, fewer personnel configuration, and low operating costs during the system construction process. The pneumatic conveying switching system of the present invention can not only ensure the process requirements of the original conveying system for conveying to the original material dropping point, but also ensure the requirements of the new conveying system for conveying to the new material dropping point. Moreover, the system of the present invention enables the new and old two sets of storage systems to be used as backup functions for each other, providing guarantee for the safe operation of production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Structure schematic diagram of an embodiment of the pneumatic conveying switching system of the present invention;

[0023] In the drawings: 1 - tee joint; 2 - pneumatic valve; 3 - elbow; 4 - pipeline distributor; 5 - air-material mixer; 6 - air supplement device; 7 - double sleeve pipe; 8 - pressure transmitter; 9 - pneumatic shut-off valve; 10 - orifice plate; 11 - regulating valve; 12 - check valve; 13 - manual shut-off valve; 14 - compressed air main pipe; 15 - original conveying pipeline; 16 - working platform. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0025] A pneumatic conveying switching system of the present invention includes a plurality of original conveying pipelines 15 connected to the original material dropping point. A tee joint 1 is provided on each original conveying pipeline 15, and a switching pipeline is led out through the tee joint 1. One output end of the tee joint 1 is horizontally arranged, and the other output end is vertically arranged. The switching pipeline is connected to the vertically arranged output end. Each of the two output ends of the tee joint 1 is connected to a pneumatic valve 2, and the two pneumatic valves 2 are interlocked, and only one of them can be opened at the same time. A plurality of switching pipelines are merged into one pipeline through a pipeline distributor 4. In an optional embodiment, the switching pipelines of two adjacent original conveying pipelines 15 are merged into one pipeline through a pipeline distributor 4. As Figure 1As shown, the example of switching from 6 groups of single pipes to 3 groups of double sleeves is used for explanation. One input end of the pipeline distributor 4 is set horizontally, the other input end is set vertically, and the output end is set horizontally. Among them, the vertically set input end is directly connected to the corresponding switching pipeline, and the horizontally set input end is connected to the corresponding switching pipeline through an elbow 3. The air-feed mixer 5 is connected to the air supply device 6, and the outlet of the air-feed mixer 5 is connected to the double sleeve 7, which is connected to the new drop point through the double sleeve 7. The double sleeve 7 is composed of two layers of inner and outer pipes. A number of cuts are provided on the inner pipe to facilitate the circulation of compressed air, so as to achieve the effect of energy saving and no material blockage. The air supply device 6 includes a branch pipe connected to the compressed air main pipe 14. The branch pipe is equipped with a main line and a bypass pipe connected in parallel. Both the main line and the bypass pipe are equipped with a pneumatic shut-off valve 9, a throttling orifice 10, and a regulating valve 11. A check valve 12 is also installed on the main line outside the bypass pipe. The main line and the bypass pipe share this check valve 12. The air supply device 6 on each gas mixer 5 is independently installed and connected to the compressed air main pipe 14. The compressed air main pipe 14 is equipped with a manual shut-off valve 13 in front of the connection point of the air supply device 6. The double sleeve 7 is equipped with a pressure transmitter 8. When the double sleeve 7 is in operation, the pressure transmitter 8 can feedback the real-time pressure situation. The three-way joint 1, pneumatic valve 2, pipeline distributor 4, and gas mixer 5 are connected to the pipeline using flanges. The switching pipelines are all led upward through the T-joint 1, the air supply devices 6 are all arranged above the gas-material mixer 5, and the compressed air main pipe 14 is arranged above all the air supply devices 6; the horizontal height between the double sleeve 7 and the original conveying pipeline 15 is at least 2m different, and the space between the double sleeve 7 and the original conveying pipeline 15 is used to set up a working platform 16, and a new set of working platforms 16 is created to facilitate the inspection and maintenance of the upper pipeline components after the switch.

[0026] In the embodiment of the pneumatic conveying switching system of the present invention, the average material-gas ratio in the double tube 7 is not less than 30 kg / kg; the terminal speed of the double tube 7 is 12 m / s-14 m / s; and the pipe wall thickness of the double tube 7 is not less than 7 mm.

[0027] The three-way connector 1, the pneumatic valve 2 and the elbow 3 of the present invention are all made of wear-resistant materials.

[0028] The control method of the pneumatic conveying switching system of the present invention comprises the following steps:

[0029] During the system setup phase, double sleeves 7 of corresponding diameters are installed according to the new material delivery point. When the conveying distance is no more than 800m, the pressure gas of the air supply device 6 is drawn from the existing compressed air system. No additional air compressor or drying device is required.

[0030] During operation, only one of the original delivery pipeline 15 and the corresponding switching pipeline is opened at the same time.

[0031] Compared with the traditional solutions, the pneumatic conveying switching system of the present invention has less investment, quick results, convenient use, stable operation, less maintenance work, fewer personnel, and low operating costs. It can not only meet the process requirements of the original conveying system for transporting to the original warehouse, but also meet the requirements of the new conveying system for transporting to the newly added destinations. The pneumatic conveying switching system of the present invention has a function of mutual backup of two sets of storage systems, which provides guarantee for the safe operation of production.

[0032] The above are only the preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Those skilled in the art should understand that without departing from the spirit and principle of the present invention, the technical solutions can be subject to several simple modifications and substitutions, and these modifications and substitutions also fall within the protection scope covered by the claims.

Claims

1. A pneumatic conveying switching system, characterized in that: It includes several original conveying pipelines (15) connected to the original material dropping point. A three-way joint (1) is provided on each original conveying pipeline (15). A switching pipeline is led out through the three-way joint (1). The switching pipelines of two adjacent original conveying pipelines (15) are merged into one pipeline through a pipeline distributor (4); the merged pipeline is connected to an air-material mixer (5). An air supplement device (6) is connected to the air-material mixer (5). The outlet of the air-material mixer (5) is connected to a double sleeve (7), and the double sleeve (7) is connected to the new material dropping point; One output end of the three-way joint (1) is horizontally arranged, and the other output end is vertically arranged. The switching pipeline is connected to the vertically arranged output end; One input end of the pipeline distributor (4) is horizontally arranged, the other input end is vertically arranged, and the output end is horizontally arranged. Among them, the vertically arranged input end is directly connected to the corresponding switching pipeline, and the horizontally arranged input end is connected to the corresponding switching pipeline through an elbow (3); The air supplement device (6) includes a branch pipe connected to the compressed air main pipe (14). The branch pipe is provided with a main pipeline and a bypass pipe connected in parallel. Pneumatic shut-off valves (9), orifice plates (10) and regulating valves (11) are provided on both the main pipeline and the bypass pipe. A check valve (12) is also provided on the main pipeline outside the bypass pipe. The main pipeline and the bypass pipe share this check valve (12); The air supplement device (6) on each air-material mixer (5) is independently arranged and is connected to the compressed air main pipe (14). A manual shut-off valve (13) is provided on the compressed air main pipe (14) in front of the connection position of the air supplement device (6); A pressure transmitter (8) is provided on the double sleeve (7).

2. The pneumatic conveying switching system according to claim 1, wherein: Two pneumatic valves (2) are respectively connected to the two output ends of the three-way joint (1). The two pneumatic valves (2) are interlocked, and only one of them can be opened at the same time.

3. The pneumatic conveying switching system according to claim 2, characterized in that: The three-way joint (1), the pneumatic valve (2), the pipeline distributor (4) and the air-material mixer (5) are respectively flange-connected to the pipeline.

4. The pneumatic conveying switching system according to claim 1, characterized in that: The double sleeve (7) is composed of an inner and an outer layer of pipes sleeved together. Several cuts for flowing compressed air are provided on the inner layer pipe.

5. The pneumatic conveying switching system according to claim 1, characterized in that: The average material-air ratio in the double sleeve (7) is not less than 30 kg / kg; The end speed of the double sleeve (7) is 12 m / s - 14 m / s; The pipe wall thickness of the double sleeve (7) is not less than 7 mm.

6. The pneumatic conveying switching system according to claim 1, wherein: The switching pipelines are all led upward through the three-way joint (1). The air supplement devices (6) are all arranged above the air-material mixer (5). The compressed air main pipe (14) is arranged above all the air supplement devices (6); A working platform (16) for maintenance is provided between the double sleeve (7) and the original conveying pipeline (15).

7. A control method for the pneumatic conveying switching system according to any one of claims 1 to 6, characterized in that: Set the double sleeve (7) with a corresponding pipe diameter according to the situation of the new material dropping point; When the conveying distance is not more than 800m, the pressure gas of the air supply device (6) is drawn from the original compressed air system; During operation, only one of the original delivery pipeline (15) and its corresponding switching pipeline is opened at the same time.

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