Shield tunneling machine belt conveying device capable of treating water-containing muck and accurate muck weighing method

Abstract

A shield tunneling machine belt conveying device capable of treating liquid muck is characterized in that a scale type belt conveying mechanism is arranged on a supporting system, the scale type belt conveying mechanism conveys muck in a rotating mode, a vibration filtering device is arranged at the right end of the supporting system, and the vibration filtering device is located under the scale type belt conveying mechanism; a water collecting and weighing device is arranged below the vibration filtering device, a plurality of groups of high-pressure spraying devices are arranged below the scale type belt conveying mechanism, high-pressure water flow sprayed by the high-pressure spraying devices acts on the scale type belt conveying mechanism, and a method for accurately weighing the muck is provided. The requirements for efficient transportation and accurate weighing of the liquid muck in shield tunnel construction can be met, the shield construction efficiency of the liquid muck working condition is remarkably improved, the workload of field staff and the equipment fault occurrence rate are reduced, and the shield tunnel construction environment can be kept clean and tidy.

Description

Technical Field

[0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a shield machine belt conveyor capable of processing water-containing slag and a slag accurate weighing method. Background Art

[0002] In recent years, with the rapid development of transportation construction in my country, shield tunneling has been widely used as an efficient, safe and advanced construction method. Among them, the common earth pressure balance shield machine transports the slag generated by the excavation face to the slag truck at the rear through a belt conveyor. At present, the surface of the shield machine transmission belt is smooth rubber, which is suitable for slag with low water content. When the slag is in a fluid or gushing state with a high water content, it is called liquid slag. The smooth surface cannot transport the liquid slag upward, and it can only be scattered and accumulated in the tunnel at the starting position, which not only occupies the space for on-site personnel to work, but also pollutes the pipe segments and shield equipment. Before the next operation, the on-site personnel need to manually clean up the scattered slag in the narrow operating space, which not only seriously affects the construction efficiency, but also greatly increases the workload of the on-site personnel and the failure rate of the equipment. In addition, the existing shield machine slag weighing schemes include manual measurement, tonnage measurement and flow measurement. However, these traditional measurement methods have some disadvantages, which limit the accurate measurement of shield excavation slag. To this end, some scholars have improved the weighing methods, such as the new gantry crane weighing structure to achieve accurate measurement of slag, and suspended weighing bridges, etc. However, these methods cannot take into account the influence of residual slag on the belt and the moisture in the liquid slag. Therefore, the weight of the slag obtained is far from the weight of the solid components in the liquid slag, which cannot effectively guide on-site construction and aggravates the uplift or subsidence of the surface. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art, and to provide a shield machine belt conveyor device that is reasonably designed, can meet the needs of efficient transportation and accurate weighing of liquid slag in shield tunnel construction, significantly improve the shield construction efficiency of liquid slag conditions, reduce the workload of on-site personnel and the occurrence rate of equipment failures, and keep the shield tunnel construction environment clean and tidy, and can handle liquid slag, and at the same time provide a method for accurately weighing slag using the same.

[0004] The technical solution adopted to solve the above technical problems is: a shield machine belt conveyor device that can handle liquid slag, a flaked belt conveyor mechanism is arranged on the support system, the flaked belt conveyor mechanism rotates and transports the slag, a vibration filtering device is arranged at the right end of the support system, the vibration filtering device is located directly below the flaked belt conveyor mechanism, a moisture collection and weighing device is arranged below the vibration filtering device, and several groups of high-pressure spray devices are arranged below the flaked belt conveyor mechanism, and the high-pressure water flow sprayed by the high-pressure spray device acts on the flaked belt conveyor mechanism.

[0005] The scale-type belt transmission mechanism of the present invention is as follows: the belt body is provided with a left transmission wheel and a right transmission wheel, the left transmission wheel and the right transmission wheel are arranged on the two side arms of the support system, a double-axis motor, a middle upper transmission wheel, and a middle lower transmission wheel are arranged on the middle bracket of the support system, one output shaft of the double-axis motor is connected to the middle lower transmission wheel through a first belt, and the other output shaft is connected to the middle upper transmission wheel through a second belt, the middle upper transmission wheel rotates clockwise and drives the belt body to rotate, and the middle lower transmission wheel rotates counterclockwise, mudguards are arranged on both sides of the upper part of the belt body, and a plurality of groups of scale plates are arranged between the mudguards, the scale plates are arranged obliquely to the belt body, and elastic side bands are arranged between both sides of the scale plates and the belt body.

[0006] The opening direction of the scale plate of the present invention is consistent with the rotation direction of the belt body.

[0007] The high-pressure spray device of the present invention comprises: a water inlet pipe is arranged on a supporting system, a spray head is radially arranged on the outer circumference of the water inlet pipe, and the spray direction of the spray head is opposite to the opening direction of the scale plate.

[0008] The vibration filtering device of the present invention is as follows: a driving motor is arranged on a side arm of a supporting system, an output shaft of the driving motor is connected to a filtering active transmission wheel through a third belt, a filtering active transmission wheel and a filtering driven transmission wheel are arranged on the supporting system and are provided with a filtering steel belt, and filtering baffles are arranged on both sides of the filtering steel belt.

[0009] The filter steel belt of the present invention is a controllable opening and closing hole type filter structure.

[0010] The cross-sectional shape of the filtering driven transmission wheel of the present invention is a regular polygonal structure.

[0011] The moisture collection and weighing device of the present invention comprises: a water storage tank is arranged directly below the filtering vibration device, a high-precision weighing sensor is arranged inside the water storage tank, and a drainage pipe (3-2) is arranged at the bottom of the water storage tank.

[0012] The right end of the scale-type belt conveying mechanism of the present invention is arranged higher than the left end.

[0013] The invention discloses a method for accurately weighing slag of a belt conveyor of a shield machine capable of processing liquid slag, comprising the following steps:

[0014] S1. Device installation: Assemble the scale-type belt transmission mechanism, vibration filtering device, moisture collection and weighing device, high-pressure spraying device, and support system;

[0015] S2. Liquid slag transportation: When the liquid slag comes out of the screw conveyor, the open space formed by the scale plate and the belt body can store the liquid slag. At this time, the double-axis motor is started to make the belt body rotate clockwise to transport the liquid slag to a higher place and the rear in batches;

[0016] S3. Transfer of liquid slag: When the liquid slag carried by the scale-type belt conveyor reaches above the vibration filter device, the vibration filter device closes the filter holes, and as the scale-type belt conveyor rotates, a batch of liquid slag is poured onto the vibration filter device;

[0017] S4, scale belt flushing: After the scale belt conveyor rotates and dumps the liquid slag, the high-pressure spray device is started to flush the remaining slag on the scale belt conveyor. The flushed slag-water mixture also falls on the closed-cell vibration filter device. At this time, the total mass of the liquid slag is collected by the high-precision weighing sensor set on the vibration filter device;

[0018] S5. Solid-liquid separation and dumping of slag: After the scale-type belt conveyor mechanism is flushed, the filter hole is opened, and the drive motor is started. The water in the liquid slag flows into the water collection and weighing device below through vibration, so as to achieve solid-liquid separation of the liquid slag. At the same time, the vibration filter device rotates to drop all the slag on it into the slag truck;

[0019] S6. Calculation of the weight of the slag: When all the slag on the vibration filter device falls into the slag truck, the weight of the water in the water tank is collected by high-precision weighing sensors arranged on both sides of the water tank. At this time, the weight of the slag after solid-liquid separation in one operation process is calculated;

[0020] S7. Repeat the above process, transfer all the slag produced by each shield machine when it excavates one ring of segments to the slag truck, and add up the weight of the slag recorded in each cycle to get the final slag weight, and discharge the water collected in the water tank through the drainage pipe below.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) Compared with the smooth conveyor belt currently used in shield machines, the present invention adopts a flaked belt. By arranging the opening direction of the flaked plate to be consistent with the rotation direction of the flaked belt transmission mechanism, the backflow of liquid slag can be prevented, thereby significantly improving the transportation capacity of liquid slag.

[0023] (2) The flaked plate of the present invention can be opened and closed, and cooperated with the middle lower transmission wheel rotating counterclockwise, so that the flaked plate and the elastic side band can be naturally closed.

[0024] (3) The present invention can prevent liquid slag from scattering and accumulating at the starting position, thereby keeping the tunnel working environment clean, reducing the process of cleaning slag, reducing the work intensity of on-site personnel, and improving excavation efficiency.

[0025] (4) The vibration filtering device with a regular polygonal transmission shaft of the present invention can effectively achieve solid-liquid separation of liquid slag, reduce the space occupied by water in the liquid slag on the slag truck, and create conditions for accurate weighing of the liquid slag.

[0026] (5) The present invention adopts a filter belt with controllable opening and closing holes, which can accurately control the solid-liquid separation of liquid slag.

[0027] (6) The accurate weighing method of liquid slag proposed in the present invention not only takes into account the weight of the residual slag on the scale belt, but also excludes the weight of the water in the liquid slag, so that the weight of the solid components in the liquid slag can be simply and accurately calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention.

[0029] Figure 2 to Figure 5 yes Figure 1 Schematic diagram of the structure of the medium-scale belt conveyor mechanism 1.

[0030] Figure 6 , Figure 7 It is a schematic diagram of the structure of the vibration filtering device 2, the moisture collecting and weighing device 3, and the high-pressure spraying device 4 in the figure.

[0031] In the figure: 1. Scale-type belt transmission mechanism; 2. Vibration filtering device; 3. Water collection and weighing device; 4. High-pressure spraying device; 5. Support system; 1-1. Scale plate; 1-2. Elastic side band; 1-3. Fender; 1-4. Belt body; 1-5. Left rotating wheel; 1-6. Middle upper transmission wheel; 1-7. Middle lower transmission wheel; 1-8. Double-axis motor; 1-9. First belt; 1-10. Second belt; 1-11. Right transmission wheel; 2-1. Filter steel belt; 2-2. Filter baffle; 2-3. Filter active transmission wheel; 2-4. Filter driven transmission wheel; 2-5. Drive motor; 2-6. Third belt; 3-1. Water storage tank; 3-2. Drain pipe; 4-1. Water inlet pipe; 4-2. Sprinkler head. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to these embodiments.

[0033] Example 1

[0034] exist Figures 1 to 7The present invention relates to a shield machine belt conveyor device that can handle liquid slag. The device is arranged below a screw conveyor, and the slag transported by the screw conveyor falls on the upper left part of the device. Specifically, a scale-type belt conveyor mechanism 1 is arranged on a support system 5, and the scale-type belt conveyor mechanism 1 rotates and transports the slag. In this embodiment, the scale-type belt conveyor mechanism 1 is composed of a scale plate 1-1, an elastic side band 1-2, a fender 1-3, a belt body 1-4, a left rotating wheel 1-5, a middle upper transmission wheel 1-6, a middle lower transmission wheel 1-7, a double-axis motor 1-8, a first belt 1-9, a second belt 1-10, and a right transmission wheel 1-11. The belt body 1-4 is provided with a left transmission wheel 1-5 and a right transmission wheel 1-11. The left transmission wheel 1 -5 and the right transmission wheel 1-11 are driven wheels, the left transmission wheel 1-5 and the right transmission wheel 1-11 are arranged on the two side arms of the support system 5, and the middle bracket 5-1 of the support system 5 is provided with a dual-axis motor 1-8, a middle upper transmission wheel 1-6, and a middle lower transmission wheel 1-7. One output shaft of the dual-axis motor 1-8 is connected to the middle lower transmission wheel 1-7 through a first belt 1-9, and the other output shaft is connected to the middle upper transmission wheel 1-6 through a second belt 1-10. The middle upper transmission wheel 1-6 is the driving wheel, which rotates clockwise and drives the belt body 1-4 to rotate, and the middle lower transmission wheel 1-7 rotates counterclockwise. The middle lower transmission wheel 1-7 provides an upward restraining force for the belt body 1-4, and the counterclockwise rotation can also close the scale plate 1-1 and the elastic side band 1-2. Mudguards 1-3 are arranged on both sides of the upper part of the belt body 1-4, and the mudguards 1-3 prevent liquid slag from sliding down from both sides. Several groups of scale plates 1-1 are arranged between the mudguards 1-3, and the scale plates 1-1 are arranged obliquely to the belt body 1-4. Elastic side bands 1-2 are arranged on both sides of the scale plates 1-1 and between the belt body 1-4. The elastic side bands 1-2 are retractable. When liquid slag enters the space between the scale plates 1-1 and the belt body 1-4, the elastic side bands 1-2 are stretched to make the space larger to hold more liquid slag. The opening direction of the scale plates 1-1 is consistent with the rotation direction of the belt body 1-4. The space formed by the scale plates 1-1 holds the liquid slag transported by the screw conveyor, and transports the liquid slag to the right side as the scale-type belt conveyor mechanism 1 rotates, and pours it onto the vibration filtering device 2. The right end of the scale-type belt conveyor mechanism 1 is arranged higher than the left end.

[0035] A vibration filtering device 2 is arranged at the right end of the support system 5, and the vibration filtering device 2 is located directly below the scale-type belt conveyor mechanism 1. The vibration filtering device 2 is composed of a filtering steel belt 2-1, a filtering baffle 2-2, a filtering active transmission wheel 2-3, a filtering driven transmission wheel 2-4, a driving motor 2-5, and a third belt 2-6. The driving motor 2-5 is arranged on the side arm of the support system 5, and the output shaft of the driving motor 2-5 is connected to the filtering active transmission wheel 2-3 through the third belt 2-6. The filtering active transmission wheel 2-3 and the filtering driven transmission wheel 2-4 are arranged on the support system 5 and are provided with a filtering steel belt 2-1. Filter baffles 2-2 are arranged on both sides of the filtering steel belt 2-1. The filtering baffles 2-2 prevent the liquid slag from sliding off during vibration. The filtering steel belt 2-1 is a controllable opening and closing hole filtering structure, which is used for solid-liquid separation of liquid slag. The cross-sectional shape of the filter driven transmission wheel 2-4 of this embodiment is a regular polygonal structure. When rotating, its shape causes the filter steel belt 2-1 to vibrate, thereby achieving the purpose of rapid and efficient separation of liquid slag, and the slag with water removed slides along the filter steel belt 2-1 into the slag truck. High-precision weighing sensors are arranged inside the filter active transmission wheel 2-3 and the filter driven transmission wheel 2-4, which can accurately collect the weight of the slag on the filter steel belt 2-1.

[0036] A plurality of groups of high-pressure spray devices 4 are arranged below the flake belt conveyor mechanism 1. The high-pressure water flow sprayed by the high-pressure spray device 4 acts on the flake belt conveyor mechanism 1. Furthermore, the high-pressure spray device 4 is composed of a water inlet pipe 4-1 and a spray head 4-2. The water inlet pipe 4-1 is arranged on the support system 5. The spray head 4-2 is radially arranged on the outer circumference of the water inlet pipe 4-1. The spray direction of the spray head 4-2 is opposite to the opening direction of the flake plate 1-1. The impact force of the high-pressure water is used to flush out the residual liquid debris in the space of the flake plate 1-1 and make it fall onto the vibration filter device 2. A moisture collecting and weighing device 3 is arranged below the vibration filtering device 2. The moisture collecting and weighing device 3 is composed of a water tank 3-1 and a drainage pipe 3-2. The water tank 3-1 is arranged directly below the filtering vibration device 2 to collect moisture separated from the liquid slag. A high-precision weighing sensor is arranged inside the water tank 3-1 to measure the weight of the separated moisture. A drainage pipe 3-2 is arranged at the lower part of the water tank 3-1. After the excavation of one ring of pipe segments is completed, the liquid in the water tank 3-1 is discharged through the drainage pipe 3-2 below and is collected and processed by the water pump provided by the shield machine.

[0037] The above-mentioned method for accurately weighing the slag of the belt conveyor of a shield machine capable of handling liquid slag comprises the following steps:

[0038] S1. Device installation: Assemble the scale-type belt conveyor mechanism 1, the vibration filter device 2, the moisture collection and weighing device 3, the high-pressure spray device 4, and the support system 5;

[0039] S2, liquid slag transportation: when the liquid slag comes out of the screw conveyor, the open space formed by the scale plate 1-1 and the belt body 1-4 can store the liquid slag, and at this time, the double-axis motor 1-8 is started to make the belt body 1-4 rotate clockwise, and the liquid slag is transported to a higher place and the rear in batches;

[0040] S3, transfer of liquid slag: when the liquid slag carried by the scale-type belt conveyor mechanism 1 reaches above the vibration filter device 2, the vibration filter device 2 closes the filter holes, and as the scale-type belt conveyor mechanism 1 rotates, a batch of liquid slag is poured onto the vibration filter device 2;

[0041] S4, scale-type belt flushing: After the scale-type belt conveyor mechanism 1 rotates and pours out the liquid slag, the high-pressure spray device 4 is started to flush the remaining slag on the scale-type belt conveyor mechanism 1. The flushed slag-water mixture also falls on the closed-cell vibration filter device 2. At this time, the total mass m of the liquid slag is collected by the high-precision weighing sensor set on the vibration filter device 2. 1 ;

[0042] S5. Solid-liquid separation and dumping of the slag: After the flushing of the scale-type belt conveyor mechanism 1 is completed, the filter hole is opened, and the drive motor 2-5 is started. The water in the liquid slag flows into the water collection and weighing device 3 below through vibration, so as to achieve solid-liquid separation of the liquid slag. At the same time, the vibration filter device 2 rotates to drop all the slag on it into the slag truck; since the vibration will interfere with the accuracy of the high-precision weighing sensors installed in the transmission shaft 2-3 and the vibration shaft 2-4, the weighing sensors will stop working after the drive motor 2-5 is started.

[0043] S6. Calculation of the weight of the slag: When all the slag on the vibration filter device 2 falls into the slag truck, the weight of the water in the water tank 3-1 is collected by high-precision weighing sensors arranged on both sides of the water tank 3-1. 2 , at this time, calculate the weight M of the slag after solid-liquid separation in an operation process i =m 1 -m 2 ;

[0044] S7. Repeat the above process, transfer all the slag produced by each shield machine excavating one ring of segment length to the slag truck, and add up the weight of the slag recorded in each cycle to obtain the final slag weight M = ∑M i The water collected in the water storage tank 3-1 is discharged through the drain pipe 3-2 below.

Claims

1. A shield machine belt conveyor capable of processing liquid slag, characterized in that: A flaked belt conveyor mechanism (1) is arranged on the support system (5), and the flaked belt conveyor mechanism (1) rotates to transport slag. A vibration filter device (2) is arranged at the right end of the support system (5), and the vibration filter device (2) is located directly below the flaked belt conveyor mechanism (1). A moisture collection and weighing device (3) is arranged below the vibration filter device (2). A plurality of groups of high-pressure spray devices (4) are arranged below the flaked belt conveyor mechanism (1), and the high-pressure water flow sprayed by the high-pressure spray device (4) acts on the flaked belt conveyor mechanism (1).

2. A shield machine belt conveyor capable of processing liquid slag according to claim 1, characterized in that The scale-type belt transmission mechanism (1) comprises: a belt body (1-4) is provided with a left transmission wheel (1-5) and a right transmission wheel (1-11), the left transmission wheel (1-5) and the right transmission wheel (1-11) are provided on two side arms of a support system (5), a double-axis motor (1-8), a middle upper transmission wheel (1-6), and a middle lower transmission wheel (1-7) are provided on a middle bracket (5-1) of the support system (5), one output shaft of the double-axis motor (1-8) is connected to the middle lower transmission wheel (1-7) through a first belt (1-9), and the other output shaft of the double-axis motor (1-8) is connected to the middle lower transmission wheel (1-7) through a first belt (1-9). The output shaft is connected to the middle upper transmission wheel (1-6) through a second belt (1-10); the middle upper transmission wheel (1-6) rotates clockwise and drives the belt body (1-4) to rotate; the middle lower transmission wheel (1-7) rotates counterclockwise; mudguards (1-3) are arranged on both sides of the upper part of the belt body (1-4); a plurality of groups of scale plates (1-1) are arranged between the mudguards (1-3); the scale plates (1-1) are arranged obliquely to the belt body (1-4); and elastic side bands (1-2) are arranged between both sides of the scale plates (1-1) and the belt body (1-4).

3. The shield machine belt conveyor capable of processing liquid slag according to claim 2, characterized in that: The opening direction of the scale plate (1-1) is consistent with the rotation direction of the belt body (1-4).

4. A shield machine belt conveyor capable of processing liquid slag according to claim 3, characterized in that The high-pressure spray device (4) comprises: a water inlet pipe (4-1) arranged on a support system (5), a spray head (4-2) radially arranged on the outer circumference of the water inlet pipe (4-1), and a spray direction of the spray head (4-2) opposite to the opening direction of the scale plate (1-1).

5. The shield machine belt conveyor capable of processing liquid slag according to claim 1, characterized in that The vibration filtering device (2) is as follows: a driving motor (2-5) is arranged on a side arm of a supporting system (5); an output shaft of the driving motor (2-5) is connected to a filtering active transmission wheel (2-3) via a third belt (2-6); the filtering active transmission wheel (2-3) and a filtering driven transmission wheel (2-4) are arranged on the supporting system (5) and are provided with a filtering steel belt (2-1); filtering baffles (2-2) are arranged on both sides of the filtering steel belt (2-1).

6. The shield machine belt conveyor capable of processing liquid slag according to claim 5, characterized in that: The filtering steel belt (2-1) is a controllable opening and closing hole filtering structure.

7. The shield machine belt conveyor capable of processing liquid slag according to claim 5, characterized in that: The cross-sectional shape of the filtering driven transmission wheel (2-4) is a regular polygonal structure.

8. The shield machine belt conveyor capable of processing liquid slag according to claim 1, characterized in that The water collection and weighing device (3) comprises: a water storage tank (3-1) arranged directly below the filtering vibration device (2), a high-precision weighing sensor is arranged inside the water storage tank (3-1), and a drainage pipe (3-2) is arranged at the bottom of the water storage tank (3-1).

9. The shield machine belt conveyor capable of processing liquid slag according to claim 1, characterized in that: The right end of the scale-type belt conveyor mechanism (1) is arranged higher than the left end.

10. The method for accurately weighing the slag of a belt conveyor of a shield machine capable of handling liquid slag as claimed in claim 1, characterized in that The following steps are involved: S1. Device installation: assembling and forming a scale-type belt conveyor mechanism (1), a vibration filtering device (2), a moisture collection and weighing device (3), a high-pressure spraying device (4), and a supporting system (5); S2, liquid slag transportation: when the liquid slag comes out of the screw conveyor, the open space formed by the scale plate (1-1) and the belt body (1-4) can store the liquid slag, and at this time, the double-axis motor (1-8) is started to make the belt body (1-4) rotate clockwise, so that the liquid slag is transported to a higher place and the rear in batches; S3, transfer of liquid slag: when the liquid slag carried by the scale-type belt conveyor mechanism (1) reaches above the vibration filter device (2), the vibration filter device (2) closes the filter holes, and as the scale-type belt conveyor mechanism (1) rotates, a batch of liquid slag is poured onto the vibration filter device (2); S4, scale-type belt flushing: After the scale-type belt conveyor (1) rotates and pours out the liquid slag, the high-pressure spray device (4) is started to flush the residual slag on the scale-type belt conveyor (1). The flushed slag-water mixture also falls on the closed-cell vibration filter device (2). At this time, the total mass m1 of the liquid slag is collected by the high-precision weighing sensor provided on the vibration filter device (2); S5, solid-liquid separation and dumping of the slag: After the scale-type belt conveyor mechanism (1) is flushed, the filter hole is opened, and the drive motor (2-5) is started, and the water in the liquid slag flows into the water collection and weighing device (3) below through vibration, so as to achieve solid-liquid separation of the liquid slag, and at the same time, the vibration filter device (2) rotates to drop all the slag on it into the slag truck; S6. Calculation of the weight of the slag: When all the slag on the vibrating filter device (2) falls into the slag truck, the weight m2 of the water in the water tank (3-1) is collected by high-precision weighing sensors arranged on both sides of the water tank (3-1). At this time, the weight M of the slag after solid-liquid separation in one operation process is calculated. i =m1-m2; S7. Repeat the above process, transfer all the slag produced by each shield machine excavating one ring of segment length to the slag truck, and add up the weight of the slag recorded in each cycle to obtain the final slag weight M = ∑M i The water collected in the water storage tank (3-1) is discharged through the drainage pipe (3-2) below.

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