Receiving drain cleaning device

Abstract

To provide a receiving-trough cleaner simple in structure capable of efficiently removing particulate accumulated in a receiving trough.SOLUTION: A receiving-trough cleaner 30, for removing a deposit of an object conveyed fallen onto and accumulated in a receiving trough 20 provided along a transport path below a belt conveyor by water cleaning, comprises a cleaning water supply pipe 31 that extends widthwise of the receiving trough 20 and a plurality of spray nozzles 32 provided in the cleaning water supply pipe 31 in an axial direction thereof. Each of the plurality of spray nozzles 32 has an ejection port directed to eject cleaning water to a deposit on the receiving trough 20 from obliquely above and flush it downstream of the receiving trough 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cleaning device for a receiving trough provided below a belt conveyor that transports powdered material such as ore. [Background technology]

[0002] As a wet smelting method for nickel oxide ores, the high-temperature pressure acid leaching method using sulfuric acid, also known as the HPAL (High Pressure Acid Leach) method, is known. This high-temperature pressure acid leaching method differs from the conventional dry smelting method for nickel oxide ores in that it does not include dry processing steps such as reduction and drying, and instead uses a wet method to consistently process the raw nickel oxide ore until nickel sulfide is produced, making it an advantageous smelting method in terms of cost and energy consumption. In addition, even if the raw ore used is a low-grade nickel ore with a nickel content of about 1%, it is possible to efficiently increase the nickel content of the finished nickel sulfide to about 50%.

[0003] In HPAL plants that process nickel oxide ores using the above-mentioned high-temperature pressure acid leaching method, the nickel raw ore produced from the mine must be transported to the site of the HPAL plant. For this reason, the HPAL plant generally has one or more belt conveyors installed to transport the nickel oxide ore crushed by a crusher installed in the quarry of the mine to equipment such as a hopper or a stockpile nearby.

[0004] In addition, in factories other than the above HPAL plant, belt conveyors are widely used to transport powdery materials such as ores, soil, and coal. In the belt conveyors that handle the above powdery materials, problems such as meandering of the belt and damage to the side skirts provided at both ends of the belt width direction occur during long-term operation, and as a result, the powdery materials may fall from the belt conveyor and gradually accumulate on the floor surface, etc. If the powdery materials accumulated on the floor surface, etc. are left as they are, the conveying rollers of the belt conveyor may entangle the powdery materials and damage mechanisms such as bearings, resulting in poor rotation and increased resistance during conveyor travel, and idling at the head pulley, making the conveyance unstable. In addition, if the accumulated powdery materials come into contact with the belt, they may wear out and develop into major equipment problems such as breakage.

[0005] As a countermeasure to this problem, for example, Patent Document 1 discloses a technology in which a scraper acting as a belt cleaner is pressed from below against the belt traveling in the return direction near the head pulley of the belt conveyor, and a pressure roller is pressed against the belt from above, scraping off powder and granular material adhering to the surface of the belt, and the powder and granular material is collected in a collection case provided below the scraper.

[0006] However, while the technology of Patent Document 1 mentioned above can prevent powder from accumulating on the floor surface near the head pulley, it cannot prevent powder from accumulating on the floor surface other than near the head pulley, for example, along the conveying path of the belt conveyor or near the tail pulley. Therefore, there is a risk of powder falling from the belt surface along the conveying path or near the tail pulley and accumulating on the floor surface below, causing the above-mentioned unstable running and equipment troubles.

[0007] Patent Document 2 discloses a technology in which a receiving trough for receiving dust that falls from a belt conveyor is installed below the belt conveyor at an angle along the conveyance path of the belt conveyor, and a cleaning device is provided upstream of the receiving trough, from which water is intermittently poured to clean the receiving trough. The cleaning device in Patent Document 2 is designed so that the amount of washing water flowing out is greater in the latter half of the wash than in the first half of the wash, and it is described that this improves the cleaning power when cleaning the receiving trough. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Utility Model Application Publication No. 7-40628 [Patent Document 2] JP 2020-37487 A Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, when powder or granular material as the transported object adheres to the belt surface of the belt conveyor, the powder or granular material does not fall at the end on the head pulley side, but goes around to the return side and is often scraped off by a specific return roller section provided on the path on the return side. For this reason, the powder or granular material tends to accumulate in a specific position in the receiving trough installed below the belt conveyor. However, with the technology of the above-mentioned Patent Document 2, it is difficult to efficiently remove the powder or granular material accumulated in such a specific position.

[0010] The present invention has been made in consideration of the problems associated with the conventional belt conveyors described above, and aims to provide a receiving trough cleaning device of a simple structure that is capable of efficiently removing powder and granular material accumulated inside a receiving trough that is provided below a belt conveyor along the conveying path of the belt conveyor to receive the powder and granular material that falls from the belt conveyor. [Means for solving the problem]

[0011] In order to achieve the above object, the receiving trough cleaning device of the present invention is a receiving trough cleaning device that removes by washing with water the deposits of transported objects that have fallen and accumulated in a receiving trough provided along a transport path below a belt conveyor, and is composed of a cleaning water supply pipe extending in the width direction of the receiving trough, and a plurality of spray nozzles provided on the cleaning water supply pipe along its axial direction, and each of the plurality of spray nozzles has an injection port directed so as to inject cleaning water obliquely from above against the deposits on the receiving trough and to sweep them away toward the downstream side of the receiving trough. Each of the spray nozzles sprays cleaning water toward a drop point on the receiving gutter of the transported object scraped off by a spiral return roller provided on the return side of the transport path of the belt conveyor. It is characterized by: Effect of the Invention

[0012] According to the present invention, powder and granular material accumulated inside a receiving trough provided below a conveyor belt can be effectively removed with a simple structure. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic side view of a belt conveyor having a receiving trough equipped with a receiving trough cleaning device of the present invention provided therebelow. [Diagram 2] 1 is a perspective view of an embodiment of a gutter cleaning device according to the present invention; [Diagram 3] 3 is a cross-sectional view of a cleaning water supply pipe provided in the receiving trough cleaning device of FIG. 2, cut in a cross section perpendicular to its axial direction. [Figure 4] 3A is a perspective view showing a specific example of a spray pattern of a spray nozzle of the receiving gutter cleaning device of FIG. 2, and FIG. 3B is a front view of the spray nozzle's spray port. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the receiving trough cleaning device according to the present invention will be described with reference to the drawings. First, a belt conveyor with a receiving trough equipped with the receiving trough cleaning device of the present invention provided below will be described with reference to Fig. 1. The belt conveyor shown in Fig. 1 is mainly composed of a head pulley 1 and a tail pulley 2 rotatably provided at the front and rear ends, respectively, of a skeleton frame (not shown), and an endless belt B wound around both pulleys.

[0015] Among the above-mentioned conveying paths of the belt conveyor, the path on which the conveyed object is conveyed from the tail pulley 2 to the head pulley 1 is called the carrier side, and the path on which the belt B returns from the head pulley 1 to the tail pulley 2 is called the return side. A plurality of carrier rollers 3 are provided at regular intervals to support the belt B on the former carrier side, and a plurality of return rollers 4 are provided at regular intervals to support the belt B on the latter return side. Some of the return rollers 4 are spiral return rollers 4a that have the function of scraping off the adhesion of the conveyed object, which causes the belt B to meander or bend, while rotating. In addition, the most downstream return roller on the return side is a reverse type adjustment return roller 4b that has the ability to correct the meandering of the return belt.

[0016] A snap pulley 5, the mounting position of which can be adjusted, is provided immediately downstream of the head pulley 1 so that the winding angle of the head pulley 1 can be increased. This allows a larger amount of belt B to be wound around the outer circumferential surface of the head pulley 1, so that the rotational driving force of the head pulley can be transmitted to belt B more reliably, allowing it to run stably, and preventing problems such as belt B spinning freely or slipping on the outer circumferential surface of the head pulley 1.

[0017] A weight pulley 6 and a pair of bend pulleys 7 located immediately upstream and downstream of the weight pulley 6 are further provided on the return side of belt B. Tension is applied to belt B by the weight pulley 6 and the above-mentioned snap pulley 5. Furthermore, a forced centering roller 8 that presses belt B downward to center it is provided on the return side of belt B.

[0018] In a belt conveyor having the above-mentioned mechanism, the following cases can be cited as reasons why the powdered material to be conveyed falls off the conveyor surface, for example, when the powdered material is ore. That is, the ore, which is quantitatively extracted from the bottom of the hopper H by a screw feeder or the like, is placed on the end of the belt conveyor on the tail pulley 2 side, and is conveyed along a carrier-side path generally in a horizontal or diagonally upward direction toward a predetermined destination, and then falls by gravity from the end of the belt conveyor on the head pulley 1 side located at the destination. Since the ore conveyed in this way is pre-treated, such as crushed or classified, to adjust the particle size as necessary before conveying, the size of the ore at the time of conveyance is often about 150 mm or less, and it is easy for the ore to fall from both ends in the width direction of the belt B due to vibrations or the like on the way from the tail pulley 2 to the head pulley 1.

[0019] In addition, some of the ore transported by the belt conveyor may not fall at the end of the head pulley 1 side, but may remain attached to the belt surface and wrap around to the return side. To prevent this wrapping around to the return side, a primary scraper 10 and a secondary scraper 11 are attached to the head pulley 1, which scrape off the ore attached to the belt surface. However, when the moisture content of the ore is high, even these scrapers 10 and 11 may not be able to scrape off the ore from the belt surface sufficiently, and for example, ore of about 0.5 mm under may wrap around to the return side of the conveyor while remaining attached to the belt surface. Most of the ore that wraps around to the return side is scraped off by the spiral return roller 4a and falls. The above phenomenon in which the ore falls from the belt conveyor is sometimes called ore falling.

[0020] In order to receive the ore that is generated mainly due to the above-mentioned reasons, a receiving chute 20 is provided below the belt conveyor along the conveying path of belt B. The ore received in the receiving chute 20 is higher in proportion to the ore that is scraped off and falls by the spiral return roller 4a provided on the conveying path on the return side of belt B than in proportion to the ore with a relatively small particle size of about 100 mm or less that falls on the conveying path on the carrier side of belt B. Therefore, inside the receiving chute 20, deposits due to ore fall tend to form locally, which causes damage to the return roller 4 and belt B.

[0021] That is, when the ore received in the receiving culvert 20 accumulates and reaches the height of the spiral return roller 4a, the ore gets caught in the bearing, hindering the rotation of the spiral return roller 4a, which creates resistance to the movement of belt B and makes the tension of belt B unstable. As a result, stress is concentrated in the spliced ​​portion of belt B and in already damaged areas, causing belt B to break.

[0022] In order to remove deposits resulting from the transported objects that have fallen and accumulated in the receiving trough 20 provided below the conveyor belt, the receiving trough cleaning device 30 according to an embodiment of the present invention is provided in the receiving trough 20. Specifically, as shown in Fig. 2, the receiving trough cleaning device 30 according to an embodiment of the present invention is composed of a cleaning water supply pipe 31 extending in the width direction of the receiving trough 20, and a plurality of spray nozzles 32 provided on the cleaning water supply pipe 31, preferably at equal intervals along its axial direction. The cleaning water supply pipe 31 is connected to a cleaning water supply line (not shown), and cleaning water having a predetermined water pressure is introduced into the cleaning water supply pipe 31. The cleaning water supply line and the end of the cleaning water supply pipe 31 are preferably connected via a coupler 33 having a cam lock structure.

[0023] Each of the spray nozzles 32 has a nozzle directed so as to spray the cleaning water from an oblique upward direction against the deposits on the receiving chute 20 and to push them toward the downstream side of the receiving chute 20 corresponding to the downstream side of the return-side path of the belt conveyor. Specifically, as shown in FIG. 3, when viewed from the axial direction of the cleaning water supply pipe 31, the nozzle of each spray nozzle 32 is preferably directed so that the angle θ between the direction of the cleaning water sprayed toward the drop point of the ore from the spiral return roller 4a on the bottom surface 20a of the receiving chute 20 and the perpendicular line to the bottom surface 20a of the receiving chute 20 is within a range of about 35° to 55°, and more preferably 45°. In addition, the shortest distance between the center of the nozzle and the bottom surface 20a of the receiving chute 20 is preferably 110 mm to 130 mm. Furthermore, the total flow rate of the cleaning water sprayed from the spray nozzles 32 is 15 m per hour or less. 3 More than 30m 3 It is preferable that the above-mentioned condition is satisfied. This makes it possible to effectively wash away the deposits accumulated inside the receiving gutter 20.

[0024] As described above, ore falls are likely to accumulate at the point where the ore scraped off by the spiral return rollers 4a provided on the return side of the conveyor belt falls, so the receiving trough cleaning device 30 is preferably placed in a position where it can spray cleaning water toward the point where the ore scraped off by the spiral return rollers 4a falls on the receiving trough 20. In this case, it is desirable to attach the receiving trough cleaning device 30 to all spiral return rollers 4a provided on the conveyor belt at a position upstream of the point where the ore falls from them falls on the receiving trough 20, in relation to the return side of the conveyor belt.

[0025] However, when it is difficult to provide the receiving trough cleaning device 30 near the drop points from all the spiral return rollers 4a as described above due to space limitations, cost, and other reasons, it is preferable to provide the receiving trough cleaning device 30 at least near the drop points from the spiral return roller 4a attached at the position closest to the head pulley 1. The reason for this is that since the receiving trough 20 is generally provided at an incline so that the end on the lower side of the head pulley 1 is higher than the end on the lower side of the tail pulley 2, by providing the receiving trough cleaning device 30 near the drop point from the spiral return roller 4a attached at the position closest to the head pulley 1 as described above, it is expected that the deposits that have fallen from the spiral return roller 4a attached downstream of that and accumulated in the receiving trough 20 can also be cleaned. Alternatively, the receiving trough cleaning device 30 may be provided near the drop points of not all but about every other spiral return roller 4a provided along the return side transport path.

[0026] The above-mentioned receiving trough cleaning device 30 may spray cleaning water continuously or intermittently. When spraying intermittently from a plurality of receiving trough cleaning devices 30, the spray timing may be staggered. Also, the receiving trough cleaning device 30 provided near the landing point of the spiral return roller 4a attached at the position closest to the head pulley 1 may spray continuously, and the other receiving trough cleaning devices 30 may spray intermittently.

[0027] The ore slurry made by the washing water sprayed from the receiving culvert washing device 30 flows through the receiving culvert 20 and is discharged from its downstream end. The ore slurry discharged from the end of the receiving culvert 20 is temporarily stored in a pit, and then extracted by a sump pump in the pit and collected in a reservoir or the like. After that, solid-liquid separation is performed as necessary, and the ore is used as raw material in the production plant.

[0028] As described above, by using the receiving trough cleaning device of an embodiment of the present invention, even if ore being transported by a belt conveyor falls from both widthwise ends due to vibration or impact, or if ore adhering to the belt surface turns around to the return side and is scraped off by a specific roller and falls, causing it to accumulate locally inside the receiving trough, cleaning water can be sprayed in a concentrated manner on that area to remove the ore, thereby preventing problems such as belt slippage and equipment trouble caused by the deposits. EXAMPLES

[0029] A belt conveyor having a structure in which belt B is stretched over head pulley 1 and tail pulley 2 as shown in Fig. 1 was used to transport nickel oxide ore at a maximum transport capacity of 540 t / hr by running belt B at a speed of 95 m / min. In this belt conveyor, the distance between the central axis of head pulley 1 and the central axis of tail pulley 2 was approximately 163 m, and belt B had a width of 1050 mm. Below this belt conveyor, a receiving trough 20 was installed along the transport path of belt B at an inclination angle of 10.9° so that the head pulley 1 side was higher than the tail pulley 2 side.

[0030] As shown in FIG. 2, three receiving culvert cleaning devices 30 were attached to each of the three spiral return rollers 4a in the receiving culvert 20, at positions near the upstream side of the return side transport path from the falling point on the receiving culvert 20, so as to extend in the width direction of the receiving culvert 20. At this time, the distances L1, L2, and L3 from the center axis of the tail pulley 2 were about 55 m, about 59 m, and about 46 m, respectively. Each of the three receiving culvert cleaning devices 30 was composed of a washing water supply pipe 31 made of carbon steel pipe SGP and 15 spray nozzles 32 arranged at equal intervals of 70 mm in the axial direction, and was connected to a washing water supply line having a valve and a flexible pipe via a coupler 33 with a cam lock structure provided at the end of the washing water supply pipe 31. In this way, industrial water was introduced from the washing water supply line to each receiving culvert cleaning device 30.

[0031] The spray nozzle 32 used was a spray nozzle (model number: HB3 / 8U-SS, material: SUS303) manufactured by Spraying Systems Far East Company, capable of spraying cleaning water in a fan-shaped pattern with a central angle of 40°. By adjusting the valve opening of the above-mentioned cleaning water supply line, the total spray flow rate of cleaning water from the group of spray nozzles 32 installed on one cleaning water supply pipe 31 was increased to 15 m3 per hour. 3 30m from 3 was kept within the range.

[0032] When viewed from the axial direction of the cleaning water supply pipe 31, each spray nozzle 32 of each receiving tubing cleaning device 30 is oriented so that the angle θ between the direction of the cleaning water sprayed toward the point on the bottom surface 20a of the receiving tubing 20 where the ore falls from the spiral return roller 4a and the perpendicular line to the bottom surface 20a of the receiving tubing 20 is 45°, and the position is adjusted so that the shortest distance between the center of the nozzle and the bottom surface 20a of the receiving tubing 20 is 120 mm. This makes it possible to spray cleaning water obliquely from above against the deposits accumulated in the receiving tubing 20 and wash them away toward the downstream side of the receiving tubing 20 corresponding to the downstream side of the return-side transport path of the belt conveyor.

[0033] In this way, cleaning water was sprayed into the receiving trough 20 of the conveyor belt to remove the deposits. The amount of cleaning water sprayed was adjusted by adjusting the valve opening of the cleaning water supply line as appropriate according to the remaining deposits of the transported materials piled up in the receiving trough 20. For comparison, a belt conveyor equipped with the above-mentioned receiving trough 20 was operated in the same manner except that the receiving trough cleaning device 30 was not attached to the receiving trough 20.

[0034] The number of belt damages that occurred per month for belt B in each of the embodiment in which the receiving culvert cleaning device 30 was installed and operated, and the comparative example in which the receiving culvert cleaning device 30 was not installed, is shown in Table 1 below. The number of belt damages is defined as the number of times per month that belt B broke or was partially damaged due to ore accumulated on the receiving culvert 20. The operating period for the evaluation was 12 months, and the evaluation was based on the average number of belt damages.

[0035] [Table 1]

[0036] As can be seen from Table 1 above, the number of belt damages was an average of 0.08 times / month in the Example and 0.58 times / month in the Comparative Example, which shows that the provision of a receiving culvert cleaning device can effectively remove deposits caused by falling ore inside the receiving culvert. A one-tailed T-test was performed using the average values ​​of the number of belt damages for the Example and Comparative Example, and a significant difference was found in the rejection region of 2.5%. [Explanation of symbols]

[0037] 1 Head pulley 2 Tail pulley 3 Carrier Roller 4 Return roller 4a Spiral return roller 4b Reverse type adjustable return roller 5 Snap Pulley 6 Weight Pulley 7 Bend Pulley 8 Forced centering roller 10 Primary Scraper 11 Secondary scraper 20 Receiving gutter 30. Receiving drain cleaning device 31 Cleaning water supply piping 32 Spray nozzle 33 Coupler B Belt H Hopper

Claims

1. A receiving trough cleaning device that removes deposits of transported materials that have fallen and accumulated in a receiving trough provided along a transport path below a belt conveyor by washing with water, the receiving trough cleaning device comprising a cleaning water supply pipe extending in the width direction of the receiving trough and a plurality of spray nozzles provided on the cleaning water supply pipe along its axial direction, each of the plurality of spray nozzles having a nozzle directed so as to spray cleaning water diagonally from above toward the deposits on the receiving trough and to sweep them away toward the downstream side of the receiving trough, and each nozzle of the plurality of spray nozzles sprays cleaning water toward the point on the receiving trough where the transported materials that have been scraped off by a spiral return roller provided on the transport path on the return side of the belt conveyor fall.

2. The receiving trough cleaning device as described in claim 1, characterized in that the receiving trough cleaning device is provided near the point where the transported objects scraped off by the spiral return roller attached at least to a position closest to the head pulley fall onto the receiving trough.

3. The receiving trough cleaning device described in claim 1, characterized in that the multiple spray nozzles are arranged at equal intervals along the axial direction of the cleaning water supply pipe at a pitch of 30 mm or more and 100 mm or less, and each of the spray nozzles is oriented so that, when viewed from the axial direction of the cleaning water supply pipe, the angle between the spray direction of the cleaning water sprayed toward the drop point and the perpendicular line to the bottom surface of the receiving trough is 35° or more and 55° or less, the shortest distance between the center of the spray nozzle and the bottom surface of the receiving trough is 110 mm or more and 130 mm or less, and the total spray flow rate of the cleaning water is 15 m3 or more and 30 m3 or less per hour.

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