Emergency screening device and method for coal supply system

Abstract

The present invention relates to an emergency screening device and method for a coal supply system. The device includes a three-way coal drop pipe and a screening component. The screening component includes a fixed seat, a rotating shaft, vertical screen bars, and transverse screen bars. One end of the vertical screen bar is connected to the rotating shaft. There are multiple vertical screen bars, each of which is evenly spaced according to a preset spacing. Adjacent vertical screen bars are connected by transverse screen bars. The rotating shaft is rotatably connected to the fixed seat. The three-way coal drop pipe includes a first shell and a second shell. The first shell is detachably connected to the second shell. The fixed seat is detachably fixed between the first shell and the second shell. Compared with the existing technology, the present invention has the advantages of simple structure and wide application range.

Description

Technical Field

[0001] The present invention relates to the field of coal transmission devices in thermal power plants, and in particular to an emergency screening device and method for a coal supply system. Background Art

[0002] Thermal power plants generate electricity by burning coal to generate heat, and the coal used for power generation is transported to thermal power plants by ship and land. Thermal power plants are equipped with special coal unloading equipment and coal conveying equipment, as well as special coal storage yards. The coal storage yards can store about 20 days of coal under normal power generation conditions to ensure a stable supply of coal for power generation. The coal supply process of thermal power companies is as follows: coal is transported to thermal power plants by water or land, and the coal is unloaded into the coal conveying system configured in the power plant by coal unloading equipment. The coal conveyor transports the coal to the coal storage yard for storage. The coal storage yard uses special stacking equipment to stack the coal in place, and takes the coal from the coal storage yard according to the demand for coal for power generation. It is then transported to the raw coal bunker of the power generation boiler by conveyor. The coal is then made into coal powder by the coal feeder and pulverizer and sent to the boiler for combustion. Since the particle size of coal entering the coal feeder and pulverizer is limited, usually below 30mm, coal larger than 30mm may reduce the efficiency of the pulverizer. Coal larger than 100mm may cause the coal feeder to be blocked and shut down, resulting in the interruption of the coal feeder's coal supply to the boiler. However, the coal feeder can only be restored to operation after manual cleaning to unclog it, which takes a long time. During this period, the coal feeder stops running and cannot supply coal, thereby reducing the amount of coal supplied, resulting in a decrease in the heat energy of combustion and the amount of power generation. It can be seen that the shutdown of the coal feeder caused by the blockage of large pieces of coal brings great harm. If multiple coal feeders are shut down due to blockage within the same time period, the power generation will be reduced at the least, and the accident of abnormal shutdown of the thermal power unit will be caused at the worst, which will cause huge economic losses to the thermal power plant. The coal transported to power plants by ship, train or car is a mixture of coal lumps of different particle sizes, with the largest particle size reaching 300mm. Such coal obviously cannot meet the feed particle size requirements of the coal feeder and pulverizer. In order to avoid blockage due to large lumps, coal screening and crushing equipment are configured in the coal transportation system. The coal first enters the screening equipment, and the coal with a particle size larger than the specified value is separated and transported to the crushing equipment for crushing, and then transported to the lower conveyor, and finally transported to the coal feeder and into the boiler for combustion.

[0003] Although the coal conveying system is equipped with screening equipment and crushing equipment, in some special cases, large pieces of coal still have to be conveyed to the coal feeder without being crushed. This is mainly due to the following situations:

[0004] 1. When the coal crushing equipment arranged on the coal conveying system fails and cannot be put into normal use, although the coal supply to the raw coal bunker in the coal conveying system is dual-line, the two coal conveying lines serve as backup for each other, and each coal conveying line is equipped with a set of coal screening equipment and a set of coal crushing equipment. Under normal circumstances, one of the equipment on each line will fail at the same time, that is, the screening and crushing functions will be unavailable. The probability of such a situation occurring is not high, but it can happen. Once this happens, coal can only be supplied to the raw coal bunker through the bypass of the screening and crushing equipment, which will inevitably lead to unstable coal supply to the coal feeder, thereby bringing the risk of unstable operation of the unit;

[0005] 2. In thermal power plant expansion projects or new unit replacement projects, the existing coal unloading system and coal storage site are shared, and a new coal loading system is built. Due to site limitations, the new coal loading system cannot be equipped with screening and crushing equipment, and the screening and crushing equipment can only be arranged in the coal unloading system. Since the coal storage yard cannot be emptied, the necessary coal storage volume must be maintained. Therefore, the particle size of the original uncrushed coal in the coal storage yard does not meet the coal requirements of the new unit, but this coal also needs to be used, which creates a difficult problem to solve.

[0006] In summary, when the coal screening module and coal crushing module in the existing coal supply device fail, coal can only be transported through the backup bypass equipment, resulting in unstable coal supply, further affecting the stability of the unit operation and affecting the power generation of the power plant. Summary of the Invention

[0007] The purpose of the present invention is to provide an emergency screening device and method for a coal supply system in order to overcome the defects of the above-mentioned prior art that when the coal screening module and the coal crushing module in the coal supply device fail, coal can only be transported through the backup bypass equipment, resulting in unstable coal supply, further affecting the stability of the unit operation, and affecting the power generation of the power plant.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] An emergency screening device for a coal supply system comprises a three-way coal drop pipe and a screening component, wherein the screening component comprises a fixed seat, a rotating shaft, vertical screen bars and transverse screen bars;

[0010] One end of the vertical screen bar is connected to the rotating shaft. There are multiple vertical screen bars, and each vertical screen bar is evenly spaced according to a preset interval. Adjacent vertical screen bars are connected by transverse screen bars. The rotating shaft is rotatably connected to the fixed seat. The three-way coal drop pipe includes a first shell and a second shell. The first shell is detachably connected to the second shell, and the fixed seat is detachably fixed between the first shell and the second shell.

[0011] Preferably, the three-way coal drop pipe includes a first output pipe and a second output pipe, and a three-way baffle is provided between the feed ports of the first output pipe and the second output pipe. One end of the three-way baffle is connected to an adjusting shaft, and the adjusting shaft is rotatably connected to the three-way coal drop pipe.

[0012] Preferably, a push arm is provided at one end of the adjusting shaft, the push arm is vertically fixed to one end of the adjusting shaft, and one end of the push arm is connected to an electric push rod.

[0013] Preferably, a support frame is provided at the upper end of the second shell, the support frame is vertically fixed to one side of the second shell, the fixing seat is detachably connected to the support frame, and a groove matching the upper surface contour of the fixing seat is provided at the corresponding position of the lower end of the first shell.

[0014] Preferably, the fixing seat is connected to the support frame via bolts.

[0015] Preferably, the fixing seat is a bearing seat, and the rotating shaft is rotatably connected to the bearing seat.

[0016] Preferably, the vertical screen bars are in the shape of an arc structure, and the lower ends of the vertical screen bars are in the shape of an arc structure inclined upward.

[0017] Preferably, there are multiple transverse screen bars, and the spacing between adjacent transverse screen bars is greater than the spacing between two adjacent vertical screen bars.

[0018] Preferably, a plurality of notches are provided on the rotating shaft at preset intervals, the shape of the notches corresponds to the shape of the upper ends of the vertical screen bars, and the vertical screen bars are located in the notches.

[0019] Preferably, the device also includes a discharger, which includes a plowshare and a support frame, the plowshare is rotatably connected to the support frame, the support frame is arranged above the conveyor belt, the plowshare is perpendicular to the conveyor belt, and rests against the upper surface of the conveyor belt.

[0020] This solution also provides an emergency method for a coal supply system, comprising the following steps:

[0021] When the coal screening module and coal crushing module of the coal supply system fail at the same time, obtain the screening components;

[0022] Separate the first shell and the second shell, install the screening component on the support frame of the second shell, and restore the first shell;

[0023] The lower end position of the screening component is adjusted by rotating the rotating shaft, and the three-way baffle is adjusted by the motor push rod so that the upper end of the three-way baffle is in contact with the lower end of the screening component;

[0024] The conveyor belt that transports coal that does not meet the size requirements is reversed to collect the coal that does not meet the size requirements together, or an unloader is set above the conveyor belt that transports coal that does not meet the size requirements to collect the coal that does not meet the size requirements together through a plowshare for subsequent processing.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This solution disassembles the first and second shells of the three-way coal drop pipe when both the coal screening module and the coal crushing module fail, installs the fixing seat of the screening component to the corresponding position, and the screening structure composed of vertical screen bars and horizontal screen bars is located above one of the output pipes of the three-way coal drop pipe. The coal entering through the inlet of the three-way coal drop pipe that can pass through the screening structure, that is, the coal that meets the size, falls onto the conveyor belt through one of the output pipes. The coal that cannot pass through the screening structure falls onto another conveyor belt through the other output pipe of the three-way coal drop pipe, thereby achieving the screening of coal of different sizes. When the original coal screening machine and coal crusher suffer serious failures, they can still operate normally by quickly installing the screening component, thereby avoiding the shutdown of the power generation facility. At the same time, the screening component has a simple structure, high screening efficiency, and a simple and quick installation and disassembly process. It can be completed during the normal coal transportation interval and will not have an adverse impact on the coal transportation demand.

[0027] 2. In this solution, the rotating shaft can be rotatably connected to the bearing seat, and the distance between the lower end of the screening component and the side of the output pipe used to transport coal that does not meet the size requirements can be adjusted by the rotating shaft. At the same time, the electric push rod drives the push arm to make the adjustment shaft drive the three-way baffle to rotate, and then adjust the inlet of the output pipe covered by the screening component, so that the inlet of the output pipe for coal that meets the size is larger than the inlet of the coal transmission pipe that does not meet the size, thereby reducing the amount of coal that meets the size but is screened out together with the large coal, thereby improving the coal screening efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic structural diagram of the emergency device provided by the present invention;

[0029] Figure 2 A schematic structural diagram of the screening component provided by the present invention;

[0030] Figure 3 A schematic diagram of the installation structure of the emergency device provided by the present invention;

[0031] Figure 4 A schematic diagram of the structure of unloading coal through an unloader provided by the present invention;

[0032] Figure 5 A schematic diagram of the structure of unloading coal by reverse conveying of a conveyor belt provided by the present invention;

[0033] In the figure: 1. Three-way coal drop pipe, 11. First shell, 12. Second shell, 13. First output pipe, 14. Second output pipe, 15. Three-way baffle, 141. Adjusting shaft, 142. Push arm, 143. Motor push rod, 2. Screening component, 21. Fixed seat, 22. Rotating shaft, 23. Vertical screen bars, 24. Horizontal screen bars, 3. Discharger, 31. Plowshare. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0038] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0039] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", not that the structure must be completely horizontal, but can be slightly tilted.

[0040] Example 1

[0041] like Figure 1-3 As shown, this embodiment provides an emergency screening device for a coal supply system, comprising a three-way coal drop pipe 1 and a screening component 2, wherein the screening component 2 comprises a fixing seat 21, a rotating shaft 22, vertical screen bars 23 and horizontal screen bars 24;

[0042] One end of the vertical screen bar 23 is connected to the rotating shaft 22. There are multiple vertical screen bars 23, and each vertical screen bar 23 is evenly spaced according to a preset interval. Adjacent vertical screen bars 23 are connected by transverse screen bars 24. The rotating shaft 22 is rotatably connected to the fixed seat 21. The three-way coal drop pipe 1 includes a first shell 11 and a second shell 12. The first shell 11 is detachably connected to the second shell 12, and the fixed seat 21 is detachably fixed between the first shell 11 and the second shell 12.

[0043] Working principle: When both the coal screening module and the coal crushing module fail, the first shell 11 and the second shell 12 of the three-way coal drop pipe 1 are disassembled, and the fixing seat 21 of the screening component 2 is installed to the corresponding position. The screening structure composed of the vertical screen bars 23 and the horizontal screen bars 24 is located above one of the output pipes of the three-way coal drop pipe 1. The coal entering through the entrance of the three-way coal drop pipe 1 can pass through the screening structure, that is, it meets the size and falls onto the conveyor belt through one of the output pipes. The coal that cannot pass through the screening structure falls onto another conveyor belt through the other output pipe of the three-way coal drop pipe 1, thereby realizing the screening of coal of different sizes.

[0044] This solution is to disassemble the first shell 11 and the second shell 12 of the three-way coal drop pipe 1 when both the coal screening module and the coal crushing module fail, install the fixing seat 21 of the screening component 2 to the corresponding position, and the screening structure composed of the vertical screen bars 23 and the horizontal screen bars 24 is located above one of the output pipes of the three-way coal drop pipe 1. The coal entering through the inlet of the three-way coal drop pipe 1 that can pass through the screening structure, that is, the coal that meets the size, falls onto the conveyor belt through one of the output pipes, and the coal that cannot pass through the screening structure falls onto another conveyor belt through the other output pipe of the three-way coal drop pipe 1, thereby achieving the screening of coal of different sizes. When a serious failure occurs in the coal transmission device, it can still operate normally through the screening component 2, thereby avoiding the shutdown of the power generation facility. At the same time, the screening component has a simple structure, high screening efficiency, and a simple and quick installation and disassembly process.

[0045] As a preferred embodiment, the three-way coal dropping pipe 1 includes a first output pipe 13 and a second output pipe 14. A three-way baffle 15 is provided between the feed ports of the first output pipe 13 and the second output pipe 14. One end of the three-way baffle 15 is connected to the adjusting shaft 141, and the adjusting shaft 141 can be rotatably connected to the three-way coal dropping pipe 1.

[0046] Specifically, a push arm 142 is provided at one end of the adjustment shaft 141 . The push arm 142 is vertically fixed to one end of the adjustment shaft 141 . One end of the push arm 142 is connected to an electric push rod 143 .

[0047] The upper end of the second housing 12 is provided with a support frame 4, which is vertically fixed to one side of the second housing 12. A fixing seat 11 is removably connected to the support frame 4. A groove that matches the contour of the fixing seat's upper surface is provided at a corresponding position on the lower end of the first housing 11. The fixing seat 11 is connected to the support frame 4 via bolts. The fixing seat 11 is a bearing seat, and the rotating shaft 22 is rotatably connected to the bearing seat.

[0048] The rotating shaft 22 can be rotatably connected to the bearing seat 21, and the distance between the lower end of the screening component 2 and the side of the output pipe used to transmit coal that does not meet the size requirements can be adjusted by the rotating shaft 22. At the same time, the electric push rod 143 drives the pushing arm 142, so that the adjustment shaft 141 drives the three-way baffle 15 to rotate, and then adjusts the inlet of the output pipe covered by the screening component 2, so that the inlet of the output pipe for coal that meets the size is larger than the coal transmission pipe that does not meet the size, thereby reducing the amount of coal that meets the size but is screened out together with the large coal, thereby improving the coal screening efficiency.

[0049] Specifically, the vertical screen bars 23 are in an arc shape, and the lower ends of the vertical screen bars 23 are in an upwardly inclined arc shape. There are multiple transverse screen bars 24, and the spacing between adjacent transverse screen bars 24 is greater than the spacing between two adjacent vertical screen bars 23.

[0050] The gap size of the screening component 2 can be larger than the coal that meets the conditions, ensuring that the coal that meets the conditions can pass through the screening component 2 and be screened.

[0051] The rotating shaft 22 is provided with a plurality of slots at preset intervals. The shape of the slots corresponds to the shape of the upper ends of the vertical screen bars 23 , and the vertical screen bars 23 are located in the slots.

[0052] As a preferred embodiment, the device also includes a discharger 3, which includes a plowshare 31 and a support frame. The plowshare 31 is rotatably connected to the support frame. The support frame is arranged above the conveyor belt. The plowshare 31 is perpendicular to the conveyor belt and rests against the upper surface of the conveyor belt.

[0053] The support frame of the discharger 3 is set above the conveyor belt for transporting coal that does not meet the size requirements, and the coal on the conveyor belt is unloaded from the conveyor belt by the plowshare 31, and the unloaded coal is subsequently processed.

[0054] In combination with the above preferred implementations, this embodiment provides an optimal implementation, specifically:

[0055] The conventional coal transportation system of a thermal power plant always includes coal carriers, transfer stations, belt conveyors, three-way coal drop pipes, B-way tees, A-way tees, coal storage bunkers, activated feeder coal screening and crushing equipment buildings, A-way coal screeners, B-way coal screeners, A-way coal crushers, B-way coal crushers, raw coal bunkers, plow-type unloaders, and coal bunker rooms.

[0056] The process flow of coal transportation is:

[0057] Coal is transported to the power plant by coal ships. After unloading, the coal is transported to the coal storage bunker through several belt conveyors connected at the end. When coal needs to be supplied to the unit boiler, the activated feeder transports the coal from the coal storage bunker to the belt conveyor at the bottom. Then, the coal is transported to the coal bunker room through several belt-connected conveyors. The plow-type unloader unloads the coal on the belt conveyor into the corresponding raw coal bunker according to the demand for coal entry, and then enters the coal feeder at the bottom of the raw coal bunker, and is sent to the boiler system for combustion by the coal feeder.

[0058] In the coal handling system, coal is transported from the coal storage bin to the raw coal bunker. According to design specifications, two coal conveyor lines, Line A and Line B, are required. All belt conveyors and equipment on Line A are named "A" to distinguish them from Line B. The same applies to Line B. Each coal conveyor line consists of several belt conveyors connected end-to-end. The connecting device is a coal drop pipe. To facilitate switching between the two conveyor lines, the drop pipe has a three-way function, allowing one conveyor line to switch to the other. Each conveyor line between the coal storage bin and the raw coal bunker must be equipped with a three-way drop pipe to improve coal handling reliability. This section of the coal conveyor line is equipped with a coal screener on Line A, a coal screener on Line B, a coal crusher on Line A, and a coal crusher on Line B. After screening, large coal lumps are fed into the coal crusher for crushing. This equipment ensures that the coal particle size does not exceed the specified value, meeting the feed requirements of the coal feeder.

[0059] The two belt conveyors connected to each other along the coal transportation direction on the coal transportation line are divided into the upper belt conveyor and the lower belt conveyor, such as: the upper belt conveyor, the upper belt conveyor, which transport the coal to the lower belt conveyor and the lower belt conveyor. The belt conveyor is provided with a head cover to prevent coal dust and coal from overflowing. A transfer station is provided at the coal transportation connection of the two belt conveyors. The coal screening machine and the coal crusher are arranged in the screening and crushing equipment building. The three-way coal drop pipe and the three-way coal drop pipe are arranged in the first transfer station for coal output from the coal storage bin. The coal transported on a belt conveyor is guided to the lower belt conveyor on the coal transportation line A or the coal transportation line B through the three-way coal drop pipe.

[0060] The three-way coal drop pipe is mainly composed of an upper coal inlet, that is, the upper body of the head cover and the lower body of the head cover. There are two coal drop pipes at the lower part, a three-way A-way coal drop pipe and a three-way B-way coal drop pipe. These two coal drop pipes are respectively aligned with different parallel belt conveyors. A three-way baffle is provided in the middle. The three-way baffle push arm can be driven by an electric push rod to rotate the three-way baffle around the rotating shaft to close or open the two lower coal drop pipes, so that the coal at the entrance enters the inlet of the opened lower coal drop pipe, thereby guiding the coal to the lower belt conveyor on different coal transportation lines, thereby realizing the switching and change of the coal transportation line.

[0061] like Figure 1-3 As shown, this solution is to add a temporary screening component to this coal conveying line. The screening component consists of vertical screen bars 23, transverse screen bars 24, a rotating shaft 22 and a bearing seat 21. The coal is screened through the sieve holes formed by the vertical screen bars 23 and the transverse screen bars 24. The vertical screen bars 23 have arc-shaped features, which can improve the coal screening efficiency. The spacing between the vertical screen bars 23 is set to the maximum coal particle size that will not cause coal blockage in the coal feeder.

[0062] This embodiment provides a layout scheme for the screening component 2: the screening component is arranged on the first three-way coal drop pipe along the coal conveying direction on the upper coal conveying line between the coal storage bin and the raw coal bin, that is, the three-way coal drop pipe of line B or the three-way coal drop pipe of line A, and the screening component is arranged on one of the two-way coal conveying lines, and the upper body of the head cover of the upper belt conveyor of line A is removed to open the upper part of the three-way coal drop pipe, and a support seat is installed and fixed on both sides of the upper opening of the lower body of the head cover to support and fix the rotating shaft of the screening component, and then the screening component is placed in, and the bearing seat of the screening component is connected to the support seat by bolts. In this way, the screening component can rotate around the center of the bearing seat at a certain angle, and at the same time, the three-way baffle is pushed to rotate to a position by driving the electric push rod. This position deviates from the center line of the upper opening of the two coal drop pipes by a certain distance, which is about 3 / 5 of the entire upper opening. This can improve the screening efficiency and reduce the coal that is screened out together with the large pieces of coal although the particle size is smaller than the screening size.

[0063] The other end of the vertical screen bar 23 of the screening component 2 is placed on the upper part of the three-way baffle, thus forming a screening function on one of the two coal output coal drop pipes of the three-way coal drop pipe. This screening component ensures that the particle size of the coal passing through meets the requirements. When the screening component is installed in place, the upper body of the head cover can be reinstalled, and a groove is set on the head cover to correspond to the rotating shaft of the installed screening component.

[0064] Large lumps of coal separated by the screening unit 2 fall through the three-way coal drop pipe on the A-way conveyor and onto the lower belt conveyor on the B-way conveyor. A discharger 3 can be installed on the B-way conveyor. When the plowshares 31 of the discharger 3 fall onto the conveyor belt surface, the plowshares 32 separate the large lumps of coal from the conveyor line. The coal is then transported by vehicle to a designated crushing and processing facility for recycling. When screening is no longer needed, the screening unit can be removed from the conveyor line. This is simple and quick removal, and does not affect the coal supply required for boiler combustion.

[0065] This embodiment also provides the working principle of the screening component:

[0066] In the coal transportation system of thermal power plants, the coal transportation lines from the coal storage bin to the raw coal bin are all arranged as double coal transportation lines, and each coal transportation line is equipped with a set of three-way coal drop pipes to ensure that the two lines can borrow some coal transportation equipment from each other to transport coal, thereby improving the reliability of coal transportation. The coal supply capacity of each of the two coal transportation lines can meet the coal supply required for normal power generation of the boiler, so the two coal transportation lines are backup for each other. Based on this feature, under the premise of ensuring the reliability of the operation of the single-way conveyor, the use of a single-way coal transportation line can also meet the coal demand of the boiler; at the position of the three-way coal drop pipe, the upper belt conveyor of one line can transport coal to the two lower belt conveyors, so that the coal transported by the single line is divided into the lower two-way belt conveyor at the three-way coal drop pipe. On the other hand, by using this feature, a screening component is placed at the three-way coal drop pipe, so that the coal with appropriate particle size falls onto one lower belt conveyor, and the coal blocks with particle size larger than the sieve size of the screening component fall onto the other lower belt conveyor, so that the coal transported by the upper belt conveyor is screened by the screening component arranged on the three-way coal drop pipe. The coal with appropriate particle size is transported to the raw coal bunker through the coal transportation line to meet the coal demand of the boiler system. There are two ways to deal with the large coal blocks transported on the belt conveyor of the other coal transportation line, such as Figure 4 As shown in FIG, one method is to unload the large pieces of coal from the coal transportation line by setting a plow-type discharger on the belt conveyor; Figure 5 As shown, the other is to suspend a shorter belt conveyor (wheelbase less than meters) in the coal transportation line by changing the conveying direction, that is, the conveyor conveys in the reverse direction, and at the same time modify the rear part of the coal guide chute so that large pieces of coal can be unloaded from the tail of the belt conveyor.

[0067] These two methods cause relatively little change to the belt conveyor and are easy to install and dismantle. The coal handling system is also easy to modify and restore. The disassembly and assembly work requires a short construction period and can be completed during the normal coal handling interval. It will not have an adverse effect on the coal handling demand. The unloaded large pieces of coal are transported by vehicle to a designated location for crushing and then can be recycled. The temporary screening method can be installed at only a single-way three-way coal drop pipe or at both ends. This depends entirely on actual needs. However, after the screening components are installed, the dual-way coal supply characteristics of the original coal handling system are changed to a single-way coal supply. Therefore, this method is a temporary emergency plan. Once the original screening equipment and crushing equipment in the coal handling system are put into normal use, the temporarily installed screening components can be removed from the coal handling system, restoring the original coal handling characteristics. This plan is an emergency guarantee plan, which is a means to ensure the normal and stable power generation and continuous coal supply of thermal power plants. At the same time, it is used when the new units are built but the screening and crushing equipment is not put into operation during the expansion and renovation of thermal power plants, or when the newly built screening and crushing equipment is arranged on the coal transportation line of the input section of the coal storage bunker. At this time, there will always be a certain amount of unscreened coal in the coal storage bunker, and this part of the coal cannot be directly fed into the coal feeder. This plan provides such a solution.

[0068] The configuration of coal transportation systems in domestic thermal power plants all follow the same specifications. Therefore, when similar problems are encountered in the coal transportation systems of thermal power plants, such solutions can be used to solve the problems, thereby maximizing the stability of coal supply to thermal power units and having a wide range of applications.

[0069] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. An emergency method for an emergency screening device of a coal supply system, characterized in that: The emergency screening device comprises a three-way coal drop pipe (1) and a screening component (2), wherein the screening component (2) comprises a fixed seat (21), a rotating shaft (22), vertical screen bars (23) and transverse screen bars (24); One end of the vertical screen bar (23) is connected to the rotating shaft (22), the number of the vertical screen bars (23) is multiple, and the vertical screen bars (23) are evenly spaced according to a preset spacing. Adjacent vertical screen bars (23) are connected by transverse screen bars (24). The rotating shaft (22) is rotatably connected to the fixed seat (21). The three-way coal drop pipe (1) includes a first shell (11) and a second shell (12). The first shell (11) is detachably connected to the second shell (12). The fixed seat (21) is detachably fixed between the first shell (11) and the second shell (12). The emergency method comprises the following steps: When the coal screening module and coal crushing module of the coal supply system fail at the same time, obtain the screening components; Separate the first shell and the second shell, install the screening component on the support frame of the second shell, and restore the first shell; The lower end position of the screening component is adjusted by rotating the rotating shaft, and the three-way baffle is adjusted by the motor push rod so that the upper end of the three-way baffle is in contact with the lower end of the screening component; The conveyor belt that transports coal that does not meet the size requirements is run in reverse so that the coal that does not meet the size requirements is discharged from the tail of the conveyor belt, and then the coal that does not meet the size requirements is collected together; or an unloader is set above the conveyor belt that transports coal that does not meet the size requirements, and the coal that does not meet the size requirements is unloaded by a plowshare and collected together for subsequent processing.

2. The emergency method of the emergency screening device of the coal supply system according to claim 1, characterized in that: The three-way coal dropping pipe (1) comprises a first output pipe (13) and a second output pipe (14); a three-way baffle (15) is provided between the feed ports of the first output pipe (13) and the second output pipe (14); one end of the three-way baffle (15) is connected to an adjusting shaft (141); and the adjusting shaft (141) is rotatably connected to the three-way coal dropping pipe (1).

3. The emergency method of the emergency screening device of the coal supply system according to claim 2, characterized in that: One end of the adjustment shaft (141) is provided with a push arm (142), the push arm (142) is vertically fixed to one end of the adjustment shaft (141), and one end of the push arm (142) is connected to an electric push rod (143).

4. The emergency method of the emergency screening device of the coal supply system according to claim 1, characterized in that: A support frame (4) is provided at the upper end of the second shell (12), the support frame (4) being vertically fixed to one side of the second shell (12), the fixing seat (21) being detachably connected to the support frame (4), and a groove matching the contour of the upper surface of the fixing seat being provided at a corresponding position of the lower end of the first shell (11).

5. The emergency method of the emergency screening device of the coal supply system according to claim 4, characterized in that: The fixing seat (21) is connected to the support frame (4) via bolts.

6. The emergency method of the emergency screening device of the coal supply system according to claim 1, characterized in that: The fixed seat (21) is a bearing seat, the rotating shaft (22) is rotatably connected to the bearing seat, and the vertical screen bar (23) is in the shape of an arc structure.

7. The emergency method of the emergency screening device of the coal supply system according to claim 1, characterized in that: The number of the transverse screen bars (24) is multiple, and the spacing between adjacent transverse screen bars (24) is greater than the spacing between two adjacent vertical screen bars (23).

8. The emergency method of the emergency screening device of the coal supply system according to claim 1, characterized in that: The rotating shaft (22) is provided with a plurality of notches at preset intervals, the shape of the notches corresponding to the shape of the upper ends of the vertical screen bars (23), and the vertical screen bars (23) are located in the notches.

9. The emergency method of the emergency screening device of the coal supply system according to claim 8, characterized in that: The device also includes a discharger (3), the discharger (3) including a plowshare (31) and a support frame, the plowshare (31) is rotatably connected to the support frame, the support frame is arranged above the conveyor belt, the plowshare (31) is perpendicular to the conveyor belt and abuts against the upper surface of the conveyor belt.

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