Waste plastic transport equipment and waste plastic storage hopper

Abstract

The storage hopper (21) of the waste plastic transport device has a pyramidal or conical portion, and the pyramidal or conical portion is configured to measure the vertical stress Pv (kgf / m) acting on the opening (56) at the lower end from the storage hopper (21) storing the waste plastic (12). 2 ), hopper angle θ (°), cross-sectional area s of opening (56) (m 2 ), the perimeter of the opening (56) L O (m), the peripheral length L (m) of the straight body part at the top end of the storage hopper, and the discharge performance index G are observed. O , θ are used as variables to derive a relational expression that represents the discharge performance index G, and the calculation result of the relational expression is equal to or greater than a predetermined value, and (s / L O ) / L is equal to or greater than a predetermined value. This makes it possible to charge the collected waste plastic directly into the carbonization chamber, or after only minor processing.

Description

[Technical Field]

[0001] The present invention relates to a waste plastic transport device, and more particularly to a waste plastic transport device for transporting waste plastic to be charged into a coke oven carbonization chamber and a waste plastic storage hopper. [Background technology]

[0002] Conventionally, the vast amounts of waste plastic generated as industrial plastic waste and general plastic waste have been disposed of by landfilling or partial incineration. When landfilled, waste plastics are not decomposed by bacteria in the soil, and when incinerated, the high heat output has a negative impact on incinerators. Furthermore, in the case of chlorine-containing waste plastics, the disposal of the chlorine in the exhaust gas poses a problem. Given the predicted future shortage of landfill sites and growing environmental concerns, there is a desire to promote the recycling of waste plastics. Possible recycling methods include reuse as plastic, utilization of the heat generated during combustion, and the use of gases and oils obtained through thermal decomposition during heating as fuels or chemical raw materials.

[0003] For example, Patent Document 1 discloses a method for recycling waste plastics by mixing plastic granules molded at 100 to 160°C with coal and carbonizing the mixture in a coke oven. On the other hand, Patent Document 2 describes that mixing a large amount of plastic reduces the strength of the resulting coke, and that to keep the reduction in coke strength to a few percent, the mass ratio of plastic to coal needs to be 1% or less, and that the amount that can be recycled is limited depending on the target level of coke strength.

[0004] As a method for adding waste plastics to a coke oven for processing, a method in which the waste plastics are charged into the space above the coal charged in the coke oven (hereinafter referred to as the "top space") is known.

[0005] Patent Document 2 discloses a method for pyrolysis recycling in which coke raw materials containing 30% by mass or more of non- or slightly caking coal are charged into the carbonization chamber of a coke oven, and then waste plastics are charged into the furnace top space above the coke raw materials. By pre-molding, the waste plastics are recycled to a size where the ratio of sieve openings under 10 mm is 20% by mass or less and the specific surface area is 500 mm. 2 By making the granules into particles with a density of 1 / g or less and then charging the particles into the carbonization chamber, the sudden generation of gas can be suppressed, making it possible to recycle a large amount of waste plastic.The company also states that extrusion molding machines and double-roll molding machines can be used to pre-mold the waste plastic.

[0006] According to Patent Document 3, in a method in which coke raw materials are first charged into the carbonization chamber of a coke oven and then waste plastics are charged into the top space, it is possible to thermally decompose most of the waste plastics in the high-temperature coke oven, resulting in high-calorie pyrolysis gases containing hydrogen, methane, ethane, propane, etc., which are contained in the coke oven gas generated in the coke oven carbonization chamber by the thermal decomposition of coal and recovered for reuse as an energy source. Patent Document 3 also states that it is preferable to reduce and solidify the waste plastics and use high-density lumps of waste plastics. In an example in the same document, a mixture of waste plastics is reduced and solidified, with an average particle size of approximately 20 mm.

[0007] Patent Document 4 discloses a method for producing coke by carbonizing coal in a coke oven and then charging waste plastics into the upper space of the carbonization chamber. The document also describes a method for charging polymer waste while shielding it from the atmosphere, in which a hopper is provided on a charging car and a cylindrical chute is set at the coal inlet of the coke oven to charge the waste (see Figure 5 of the document).

[0008] Patent Document 5 discloses a method in which a coke oven is provided with a carbonization chamber in which no coal is charged, waste plastics are charged into the carbonization chamber while heating the interior of the carbonization chamber to a predetermined temperature, and pyrolysis is carried out, and the pyrolysis gas is recovered together with the coke oven gas. According to Figure 1 of the same document, waste plastics are charged into a coal car through a loading hopper for waste plastics and a damper at its bottom, and further through a charge hopper below that and a damper at its bottom, and then through a charging port.

[0009] Patent Document 6 discloses a method for charging coal and waste plastics into a coke oven, in which waste plastics are loaded into a charge hopper of a coal-loading car, followed by coal, and the loaded materials are then removed from the bottom of the charge hopper and charged into the carbonization chamber. According to Figure 1 of the document, a waste plastic storage tank is located adjacent to the coal tower, with a weighing hopper below it. First, waste plastics are dropped into the charge hopper of the coal-loading car from the weighing hopper, and then a predetermined amount of coal is loaded from the coal tower 30 onto the previously loaded waste plastics in the charge hopper by normal operation. Next, as shown in Figure 4, the raw materials from the charge hopper, with the waste plastics at the bottom and the coal on top, are removed and charged into the carbonization chamber using the same operation as normal raw material charging.

[0010] Patent Document 7 discloses a method of charging coal, waste plastics, and coal from below into a charge hopper of a coal charging vehicle, and then charging the coal and waste plastics from the charge hopper into the carbonization chamber of a coke oven. Figure 1 shows a waste plastic bin into which waste plastics are charged and a coal bin into which coal is charged. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-49261 [Patent Document 2] Japanese Patent Application Publication No. 2019-135278 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-47494 [Patent Document 4] Japanese Patent Application Publication No. 4-41588 [Patent Document 5] Japanese Patent Application Publication No. 10-237454 [Patent Document 6] Japanese Patent Application Publication No. 09-132780 [Patent Document 7] Japanese Patent Application Laid-Open No. 2001-115163 [Non-patent literature]

[0012] [Non-Patent Document 1] Chemical Engineering Handbook, 5th Revised Edition, March 18, 1988, pp. 868-869 Summary of the Invention [Problem to be solved by the invention]

[0013] In a method of treating waste plastics by charging them into the furnace top space 5 above the charged coal 11 in the carbonization chamber 2 of a coke oven 1 (see FIG. 10), a transport device is required to transport the waste plastics 12 to be charged into the carbonization chamber 2 to the top of the coke oven. Typically, as shown in FIG. 10, the waste plastics 12 are transported to the vicinity of the coke oven by truck 45 or the like, and then the waste plastics 12 are loaded from the truck 45 into ground hoppers 22. Above the coke oven, furnace hoppers 23 for waste plastics are installed. The number of furnace hoppers 23 is the same as the number of charging openings 4 in the furnace length direction of the carbonization chamber 2. To transport the waste plastics 12 from the ground hoppers 22 to the furnace hoppers 23, the waste plastics 12 are discharged from a discharge device 24 installed at the bottom of the ground hopper 22, and then lifted to the top of the coke oven by a flight conveyor 25 or the like, where the required amount of waste plastic is discharged into each furnace hopper 23 by a distribution and discharge device 26.

[0014] As a hopper for charging waste plastic 12 through the charging port 4 of the carbonization chamber, the charge hopper for charging coal provided on the coal loading car 41 may be used as is (see Patent Documents 2, 6, and 7), or a charging hopper dedicated to charging waste plastic may be provided on the same coal loading car 41 or on a mobile cart provided separately from the coal loading car 41 so as to be movable in the direction of the furnace battery length (see Patent Documents 4 and 5). The same number of charge hoppers and charging hoppers are arranged in the furnace length direction of the carbonization chamber as the number of charging ports 4.

[0015] Regarding the shape of the waste plastics to be charged into the carbonization chamber, Patent Document 2 describes a method of pre-molding the waste plastics so that the ratio of sieve openings under 10 mm is 20% by mass or less and the specific surface area is 500 mm 2 The waste plastics are then converted into granular material of 0.1g or less and charged into the carbonization chamber. Patent Document 3 describes that it is preferable to reduce the volume of waste plastics and solidify them, and to use high-density lumps of waste plastics, and in the working examples of the same document, a mixture of waste plastics is reduced in volume and solidified, and lumps with an average particle size of about 20mm are used.

[0016] Premolding or volume-reducing and solidifying collected waste plastics requires the installation of processing equipment. This also increases the processing costs. However, collected waste plastics vary in size, have low bulk density, and contain membrane-like particles. When premolding or volume-reducing waste plastics, or when loading them directly or only lightly processed into a carbonization chamber, conventional transport devices can encounter problems such as clogging. For example, the waste plastic loading hopper (11) shown in Figure 1 of Patent Document 5 has a small opening at the bottom of the damper (13a), which can cause clogging. Furthermore, a waste plastic storage tank (20) with a shape similar to that shown in Figure 1 of Patent Document 6 can result in waste plastics piling up at the bottom of the storage tank (20). In the tanks and hoppers shown in Figures 1 and 3 of Patent Document 7, the cross-sectional area of ​​the hopper is narrowed below the body of the hopper, resulting in a so-called "hanging shelf" condition, which prevents the load (plastic) from descending properly and sequentially, creating a space below, which can cause a stagnation in continuous discharge.

[0017] The present invention aims to provide a waste plastic transport device, particularly a waste plastic transport device for transporting waste plastic to be charged into a coke oven carbonization chamber, which does not cause problems such as the waste plastic clogging the transport device even if the recovered waste plastic is pre-molded and volume-reduced, or even if it is charged into the carbonization chamber as is or after only light processing, and a waste plastic storage hopper. [Means for solving the problem]

[0018] That is, the gist of the present invention is as follows. [1] A waste plastic transport device for supplying waste plastic into a coke oven carbonization chamber from a charging port provided in the ceiling of the coke oven carbonization chamber, The waste plastic transport device has a waste plastic storage hopper in the middle of the transport route, and the storage hopper has a part in which the surface that comes into contact with the waste plastic is pyramidal, rectangular tubular, conical, or cylindrical, The lower end of the storage hopper is open, The vertical stress Pv (kgf / m) applied to the bottom end of the storage hopper storing waste plastics 2 ), tan θ calculated from the hopper angle θ (°) of the storage hopper, the cross-sectional area s (m 2 ), the peripheral length L of the opening O (m), the peripheral length L (m) of the upper end of the storage hopper, X, which is the calculation result obtained by substituting the actual value of tanθ into a relational expression that represents the dischargeability performance index obtained by observing the dischargeability performance, is equal to or greater than a predetermined value, and (s / L O ) / L is equal to or greater than a predetermined value, Waste plastic transport equipment. However, the above relational expression is based on the above Pv, the above s, and L O Based on (s / L O ) and the relational expression derived using tan θ as a variable. In addition, when the surface that contacts the waste plastic is pyramidal, the hopper angle θ refers to the angle between the horizontal plane and a plane that is perpendicular to both the pyramidal surface and the horizontal plane, and when the surface is conical, the hopper angle θ refers to the angle between the horizontal plane and a plane that is perpendicular to any part of the surfaces that make up the cone and is perpendicular to the horizontal plane (hereinafter referred to as the "orthogonal plane"). In the case of the rectangular tube or cylindrical shape, the hopper angle θ is 90°.

[0019] [2] The relational expression is the following expression (1), and the value of X in expression (1) is 2.00 or more, The above (s / L O ) / L is 0.025 or more, [1] A waste plastic transport device according to the present invention. X=1123907·(Pv) -1.55 ·(s / L O )2 (tanθ) 0.46 (1)

[0020] [3] The waste plastic transport device according to [1] or [2], characterized in that the storage hopper includes one or more of a ground hopper, a furnace hopper, an input hopper, and a charge hopper. [4] A waste plastic transport device as described in [3], characterized in that a waste plastic feeder is arranged at the lower end of one or more of the ground hopper, furnace hopper, feeding hopper, and charge hopper, and the waste plastic feeder is one of a screw feeder, circle feeder, table feeder, rake feeder, and apron feeder.

[0021] [5] A waste plastic storage hopper used in the waste plastic transport device described in any one of [1] to [4].

[0022] The present invention relates to a storage hopper used in a waste plastic transport device for supplying waste plastic into a coke oven carbonization chamber from a charging port provided in the ceiling of the coke oven carbonization chamber. The surface that comes into contact with the waste plastic has a pyramidal or conical portion, and the angle θ is determined by a predetermined definition, and the discharge outlet cross-sectional area s / discharge outlet peripheral length L O By making the shape of the plastic waste satisfy the desired dischargeability determined by the above, it becomes possible to load the recovered waste plastic into the carbonization chamber as it is or after only minor processing, if the recovered waste plastic has been pre-molded and volume-reduced. [Brief explanation of the drawings]

[0023] [Figure 1A] FIG. 1 is a plan view of an example storage hopper. [Figure 1B] 1B is a front cross-sectional view of an example of a storage hopper taken along the line BB in FIG. 1A. [Figure 2A] FIG. 10 is a plan view showing an example of a storage hopper. [Figure 2B] 2B is a front cross-sectional view of an example of a storage hopper taken along the line BB in FIG. 2A. [Figure 3A] FIG. 1 is a plan view of an example storage hopper equipped with a screw feeder. [Figure 3B] 3B is a front cross-sectional view taken along the arrow BB in FIG. 3A, showing an example of a storage hopper equipped with a screw feeder. FIG. [Figure 4A] FIG. 1 is a plan view of an example storage hopper with a circle feeder. [Figure 4B] 4B is a front cross-sectional view taken along the arrow BB in FIG. 4A, showing an example of a storage hopper equipped with a circle feeder. FIG. [Figure 5A] FIG. 1 is a plan view of an example storage hopper with a table feeder. [Figure 5B] 5B is a front cross-sectional view taken along the arrow BB in FIG. 5A, showing an example of a storage hopper equipped with a table feeder. FIG. [Figure 6] FIG. 1 is a cross-sectional front view of an example storage hopper with a rake feeder. [Figure 7] FIG. 1 is a front cross-sectional view showing an example of a storage hopper equipped with an apron feeder. [Figure 8] FIG. 1 is a diagram showing an example of a transport device for waste plastics in a coke oven. [Figure 9] FIG. 1 is a diagram showing an example of a transport device for waste plastics in a coke oven. [Figure 10] FIG. 1 is a diagram showing an example of a transport device for waste plastics in a coke oven. [Figure 11] FIG. 2 is a perspective view showing an example of a storage hopper. [Figure 12] FIG. 10 is a diagram showing the relationship between the calculated emission index value X and the emission performance index G. [Figure 13] FIG. 10 is a diagram showing the relationship between the hopper angle θ and the discharge performance index G. [Figure 14] FIG. 10 is a diagram showing the relationship between (s / LO) / L and the discharge performance index G. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to a waste plastic transport device (see Figure 10) for supplying waste plastics 12 into the carbonization chamber 2 of a coke oven 1 through a charging port 4 installed in the ceiling of the chamber, and a waste plastic storage hopper used in the waste plastic transport device. The transport device of the present invention includes a storage hopper of the present invention capable of temporarily storing various types of waste plastics, and a feeder capable of efficiently discharging / supplying the waste plastics from the storage hopper to the next process. As previously mentioned, the waste plastics 12 charged into the carbonization chamber 2 have often been pre-molded or compacted and solidified from recovered waste plastics. In contrast, new waste plastic processing methods, such as crushing irregular shapes to approximately 30 mm in size, are being considered to simplify pre-processing as much as possible. Without pre-molding or compaction using an extrusion molding machine or double-roll molding machine, the waste plastics retain their original shape as collected, even though they are crushed. It has been found that when waste plastics are pre-molded or pre-reduced, or when the waste plastics are loaded into the carbonization chamber as is or after only minor processing, problems arise such as the waste plastics clogging the transport device that has been commonly used up until now.

[0025] As described above, the waste plastics to be charged into the carbonization chamber 2 are transported to the top of the coke oven 1 and then charged into the carbonization chamber. As shown in Figures 8-10, the following transport devices are arranged: a ground hopper 22 (where the waste plastics are initially supplied by truck or other means from the outside) on the ground; an over-furnace hopper 23 (which temporarily and stably stores the waste plastics to be charged into the coke oven) at the top of the coke oven; a feed hopper 43 (dedicated to waste plastics, separate from coal, which prepares and stores the required amount of waste plastic at each designated charging port and charges the waste plastics 12 through the charging port 4 of the carbonization chamber); and a charge hopper 42 (shared with coal, which prepares and stores waste plastics in the same way as the feed hopper 43 and charges the waste plastics 12 through the charging port 4 of the carbonization chamber). These are collectively referred to as waste plastic storage hoppers 21. That is, the waste plastic transport device of the present invention has a waste plastic storage hopper 21 along the transport route.

[0026] The storage hopper 21 has a cylindrical shape, such as a rectangular or cylindrical section at the top, and a pyramidal, rectangular, conical, or cylindrical section at the bottom. That is, the storage hopper has a pyramidal, rectangular, conical, or cylindrical section on the surface that comes into contact with the waste plastic. The cross-sectional area of ​​pyramids and cones decreases as they go downward, and they have a flat section at the bottom, so strictly speaking, pyramids can be said to be inverted truncated pyramids, and cones can be said to be inverted truncated cones. Next, the inclination angle (hopper angle θ) of the surfaces constituting the pyramid or cone is defined. Note that in the case of a rectangular tube or a cylinder, the hopper angle θ is 90°. Furthermore, the hopper angle θ is defined to be greater than 90° when the target surface 51 is overhanging.

[0027] The case of a pyramid will be explained using Figures 1A and 1B. When the pyramid is a square pyramid, there are four faces 51 that constitute the pyramid. Figure 1A is a view of the hopper from below (from the bottom end 55 of the pyramid), and the opening 56 at the bottom end 55 of the pyramid is indicated by dotted hatching. In the present invention, for each face that constitutes the pyramid, the angle formed by the intersection 54 of the face 51 with a plane (orthogonal plane 53) that is perpendicular to both the face (face 51 in Figure 1) and the horizontal plane 52, is defined as the hopper angle θ. In the example of Figure 1, the faces 51 include the left face 51A, the right face 51B, the upper face 51C, and the lower face 51D in Figure 1A. Of these four faces, the left face 51A will be discussed below. In FIG. 1, a plane perpendicular to both the surface 51A and the horizontal plane 52 is defined as an orthogonal plane 53, and an intersection line 54 between the orthogonal plane 53 and the surface 51A is determined. The angle between the intersection line 54 and the horizontal plane 52 is a hopper angle θ A The cross section BB is a plane 53 perpendicular to the plane 51. In FIG. 1B, the horizontal plane 52 is shown as a straight line. In FIG. 1B, the hopper angle θ of the plane 51B is θ B Similarly, for the surfaces 51C and 51D, the hopper angle θ C , θ D can be obtained.

[0028] The case of a cone shape will be explained with reference to Figures 2A and 2B. Figure 2A is a view of the hopper viewed from below (from the bottom end 55 of the cone), and the opening 56 at the bottom end 55 of the cone is indicated by dot hatching. The surface 51 constituting the cone is composed of a single curved surface. In the present invention, when a surface (orthogonal surface 53) that is orthogonal to any part of the surfaces constituting the cone and perpendicular to the horizontal plane 52 is assumed, the angle formed by the intersection line between the arbitrary surface and the orthogonal surface 53 and the horizontal plane is defined as the hopper angle θ. In the example shown in Figure 2, a part of the surface 51 (surface 51A including the intersection line 54 in Figure 2) is taken as the arbitrary surface, and the taken surface 51A is defined as surface 51. A surface (orthogonal surface 53) that is orthogonal to surface 51A and perpendicular to the horizontal plane 52 is assumed, and the intersection line 54 between surface 51A and the orthogonal surface 53 is determined, and the angle formed by the intersection line 54 and the horizontal plane 52 is defined as the hopper angle θ (θ A2, the cross section BB is a plane 53 perpendicular to the plane 51. In FIG. 2B, the horizontal plane 52 is shown as a straight line. In the example shown in FIG. 2, the hopper angle θ of the plane 51A on the left side in the circumferential direction of the cone in FIG. 2A is A The hopper angle θ can be calculated in a similar manner for any direction on the circumference of the cone. If the center of gravity of the opening shape of the upper end 57 of the inverted truncated cone differs from the center of gravity of the opening shape of the lower end 55 in a plan view, the hopper angle θ will be smallest at the position in the circumferential direction where the length of the intersection line 54 is longest when projected onto the plan view. Therefore, to calculate the minimum value of the hopper angle θ, it is sufficient to calculate the hopper angle θ at the position where the length of the intersection line 54 projected onto the plan view is longest.

[0029] A discharge device is disposed at the lower end 55 of the storage hopper 21. An opening 56 is formed at the lower end 55 of the storage hopper 21. The dotted hatched area in Figures 1A and 2A represents the opening 56. In conventional storage hopper 21, the connection portion for the discharge device has a small cross-sectional area. Therefore, a pyramidal or conical portion is provided at the bottom of the storage hopper 21 to reduce the size of the opening 56 at the lower end 55 of the storage hopper 21 accordingly. Because of the pyramidal or conical shape, the hopper angle θ has traditionally been approximately 60 to 90°. When using pre-molded or volume-reduced waste plastic 12, such pyramidal or conical storage hoppers have been used. However, when pre-molded or volume-reduced waste plastic was used, or even when the waste plastic was used directly or only lightly processed, the waste plastic would clog the storage hopper with the conventional shape.

[0030] Therefore, we came up with the idea that the above problem could be solved if the pyramidal or conical shape of the storage hopper 21 satisfied a certain relationship between the vertical stress Pv applied to the bottom end 55 of the storage hopper 21 storing waste plastic, the hopper angle θ, and the shape of the opening 56 at the bottom end 55. Therefore, we decided to quantify the effects of the above factors through model experiments. When model experiments were conducted with various changes to Pv, θ, and the discharge outlet dimensions, differences in discharge performance were observed. Furthermore, tests were conducted to confirm discharge performance by changing the discharge outlet dimensions using both the model and the actual machine.

[0031] Here, regarding the discharge status from the storage hopper, the discharge performance index G was defined as follows. G=1: Immediate blockage and drainage is delayed Although some of the waste plastic may be discharged, the discharge rate remains at zero as waste plastic remains in the hopper, and the entire amount is not discharged. G=2: Alternating stagnation and discharge is somehow discharged Even if the discharge rate temporarily drops to zero, the entire amount will eventually be discharged naturally. G=3: The discharge rate may slow slightly, but there is no obstruction. Although fluctuations in the discharge rate are observed, the state of zero discharge rate does not continue for a certain period of time, and discharge is carried out almost continuously until the entire amount is discharged. G=4: Stable emissions continue The discharge speed is stable and free fall, discharging the entire amount continuously without any stagnation. If the discharge performance index G is 2 or more, the discharge performance is judged to be good.

[0032] The vertical stress Pv (unit: kgf / m) applied to the bottom end 55 of the storage hopper 21 2 ) can be obtained by the relational expression shown in the following equation (2) from the Jansen equation (see Non-Patent Document 1). Assuming the storage hopper 21 shown in FIG. 11, the cross-sectional area of ​​the upper end 57 of the storage hopper 21 (c×d in the example of FIG. 11) is taken as the cross-sectional area A (m 2), the peripheral length of the upper end 57 (2(c+d) in the example of FIG. 11) is the peripheral length of the straight body part L (m). The total height of the storage hopper 21 (hs+hc in the example of FIG. 11) is the total height h (m), and ρ is the packing density of the waste plastic (kg / m 3 ), k: coefficient (kg / kgf). Pv=ρ·((A / L) / k)·(1-exp(-1 / (((A / L) / k)·h))) (2) The vertical stress acting on the bottom surface was measured while changing the height h of the waste plastic piled up in the model hopper, and the coefficient k was determined based on the above formula. It was found to be k = 0.07 kg / kgf.

[0033] The cross-sectional area of ​​the lower end 55 of the storage hopper 21 shown in FIG. 11 (a×b in the example of FIG. 11) is defined as the opening cross-sectional area s (m 2 ), and the peripheral length of the lower end 55 (2(a+b) in the example of FIG. 11) is the opening peripheral length L O The shape of the opening 56 at the bottom end 55 of the storage hopper 21 is determined by the cross-sectional area s of the opening 56 and the perimeter L of the opening 56. O Focusing on the index s / L O Furthermore, the hopper angle was set as the index tanθ. The discharge performance index G obtained from the above model experiment was set as Pv, s / L O When regression was performed using tanθ, a strong correlation was found, and a regression equation representing G was obtained. G=f·(Pv) p ·(s / L O ) q (tanθ) r (3) f, p, q, and r are regression coefficients.

[0034] As a result of the test, the vertical stress Pv applied from the storage hopper to the opening at the bottom end, tanθ calculated from the hopper angle θ, and the cross-sectional area s of the opening / peripheral length L of the opening were calculated. OIt has been found that when the above formula is set to satisfy a predetermined relational expression, clogging of the waste plastic 12 in the storage hopper 21 and hanging on the shelves can be prevented even when pre-molding and volume reduction and solidification processing are performed, and even when irregularly shaped waste plastics crushed to about 30 mm are used without pre-molding and volume reduction and solidification processing.

[0035] The predetermined formula is preferably determined taking into consideration the discharge limit index at which waste plastics can be discharged stably.

[0036] The specific details will be explained below. A hopper experiment was conducted using a model of the storage hopper 21 shown in Figure 11. As shown in Table 1, various hopper shapes were changed and filled with waste plastic molded products, and the dischargeability of the waste plastic was observed when the opening was opened. The dischargeability performance index G was determined, and the experimental data is shown in Table 1.

[0037] [Table 1]

[0038] In response to this, the variable (Pv) under each condition was calculated based on the above formula (2) and is shown in Table 1. Furthermore, (s / L O ), (tanθ), and using a combination of these multiple data, the discharge performance is observed as the discharge performance index G, and the Pv, s, L O Based on (s / L O ), and the tan θ was used as a variable to derive the relational expression representing the discharge performance index G as shown in the following equation (3). G=f·(Pv) p ·(s / L O ) q (tanθ) r (3) Next, a multiple regression calculation was performed on the above formula (3) to determine the coefficients f, p, q, and r. The coefficients were approximately f = 1123907, p = -1.55, q = 2, and r = 0.46.

[0039] Therefore, the coefficients of the multiple regression calculation results were substituted for f, p, q, and r on the right side of the above equation (3), and the left side of the equation (3) was set to X, leading to the following equation (1). X=1123907·(Pv) -1.55 ·(s / L O ) 2 (tanθ) 0.46 (1)

[0040] The analysis results are shown in Figure 12. The vertical axis of Figure 12 is the dischargeability performance index G determined through experiments, and the horizontal axis X is the calculated discharge index value (Equation (1) above) obtained by calculating the right-hand side of Equation (1) using the coefficients determined above and the variables Pv, S / L, and tanθ determined from each experimental condition. The correlation coefficient between G and X was approximately 0.9, which was a good value. By adjusting each factor so that X ≥ 2.00, it is possible to consider a hopper shape that ensures dischargeability. Furthermore, by adjusting each factor so that X ≥ 2.50, it is possible to achieve a hopper shape with even better dischargeability. Furthermore, X ≥ 3.00 is even more preferable. It is preferable to set the upper limit of X to 6.00.

[0041] Figure 13 shows the relationship between the hopper angle θ and the discharge performance index G from the experimental data in Table 1. When θ<60°, G=1, and discharge could not be ensured. Therefore, to ensure discharge, θ≧60° is preferable. Also, θ≦75° is preferable.

[0042] Furthermore, the influence of the outlet dimensions is O The relationship between the size and dischargeability was examined, and as the dimensions c and d of the top end (straight body part) of the storage hopper increased from 1m for small to 2m for medium to large, the required s / L for ensuring discharge increased. O This is because the vertical stress Pv acting on the discharge outlet increases in proportion to the hopper size. O is divided by the peripheral length L of the top end of the storage hopper to make it dimensionless (s / L O ) / L is shown in Figure 14. In Figure 14, the size of the storage hopper is indicated by a circle for small size, a diamond for medium size, and a square for large size. (s / L O) / L<0.025, it was found that discharge could not be ensured. O ) / L≧0.025 is preferred. O ) / L is preferably set at an upper limit of 0.035.

[0043] At the lower end 55 of the storage hopper 21 for waste plastic, a feeding device 24 for feeding out waste plastic is disposed, and the shape of the opening 56 at the lower end 55 of the storage hopper 21 is determined by the size of the feeding device 24 and the size of the waste plastic to be fed out. O ) / L) is less than 0.025 and the left side X of equation (1) is less than 2. When irregularly shaped waste plastics are used that are crushed to about 30 mm without prior molding or volume reduction and solidification treatment, the waste plastics contain film-like pieces, which can spread and cause clogging at the opening 56 at the bottom of the storage hopper. In the present invention, O ) / L, by determining the value of X on the left side of equation (1), it is possible to effectively prevent clogging at the bottom end of the storage hopper, even when using irregular waste plastics that have been crushed to about 30 mm without undergoing pre-molding or volume reduction and solidification processing.

[0044] As mentioned above, the storage hopper 21 of the present invention includes one or both of the above-ground hopper 22 for waste plastics and the furnace hopper 23 for waste plastics. Furthermore, the storage hopper 21 of the present invention can be used as a charge hopper 42 or an input hopper 43 provided on a coal loading car 41 or a mobile cart that is provided separately from the coal loading car 41 and can move in the furnace battery direction (see Figures 8 and 9).

[0045] The storage hopper 21 of the present invention is a hopper having a pyramidal or conical portion, and is calculated from the hopper angle θ of the pyramidal or conical portion by the tan θ, the cross-sectional area s of the opening, and the perimeter length L of the opening. O and the peripheral length L of the top end of the storage hopper, is ((s / L OBy establishing the above-mentioned predetermined relationship between the vertical stress Pv acting on the lower opening and the vertical stress Pv at the lower opening, favorable results can be obtained. Because the shape of the opening 56 at the lower end 55 of the storage hopper 21 ensures more stable discharge than in the past, the discharge device 24 installed below the lower end 55 of the storage hopper 21 must be large enough to handle the waste plastic discharged from such a large opening. In the present invention, this problem can be solved by using any of the screw feeder 31, circle feeder 32, table feeder 33, rake feeder 34, and apron feeder 35 for the waste plastic discharge device 24 installed at the lower end of one or more of the above-ground hopper 22, furnace hopper 23, input hopper 43, and charge hopper 42.

[0046] As shown in Figures 3A and 3B, the screw feeder 31 can be used when there is a large opening 56 at the bottom end 55 of the storage hopper 21. Figures 3A and 3B show an example in which the screw feeder 31 is arranged as the discharge device 24 in the storage hopper 21 (see Figure 8) that serves as the furnace hopper 23. The waste plastic stored in the furnace hopper 23 is discharged by the screw feeder 31 and fed into the charge hopper or feeding hopper located below the discharge opening 28. An example that meets the requirements of the present invention is when θ=70°, tan θ=2.8, and Pv=433 kgf / m 2 , s=0.25m 2 , L O =2m, (s / L O ) / L=0.03, and X=2.3 on the left side of equation (1) can be exemplified.

[0047] As shown in Figures 4A and 4B, the circle feeder 32 has a bottom plate 37 and vanes 36 attached to the periphery of the bottom plate 37 at the opening 56 at the bottom end 55 of the storage hopper 21. Rotation of the bottom plate 37 causes the vanes 36 to rotate, and the vanes 36 move the waste plastic to the discharge opening 28, from which it is vertically fed downward. This arrangement can be used when the storage hopper has a large opening at its bottom end. Figures 4A and 4B show an example in which a circle feeder 32 is installed as the discharge device 24 in a storage hopper 21 (see Figures 8 and 9) that serves as the above-ground hopper 22. The waste plastic stored in the above-ground hopper 22 is discharged by the circle feeder 32 and transported via the discharge opening 28 to the top of the coke oven by the flight conveyor 25 shown in Figures 8 and 9. An example that satisfies the requirements of the present invention is one in which θ = 80°, tan θ = 6.0, and Pv = 452 kgf / m 2 , s=0.25m 2 , L O =2m, (s / L O ) / L=0.03, and X=3.1 on the left side of equation (1).

[0048] As shown in Figures 5A and 5B, the table feeder 33 has a swiveling bottom plate 37 attached to the opening 56 at the bottom end 55 of the storage hopper 21. The swiveling bottom plate 37 causes the waste plastic to fly in a circumferential direction and is supplied in parallel from the opening 38 to the discharge port 28. This can be used when the bottom end 55 of the storage hopper 21 has a large opening 56. Figures 5A and 5B show an example in which a table feeder 33 is disposed as the discharge device 24 in a storage hopper 21 (see Figure 9) that serves as the furnace hopper 23. The waste plastic stored in the furnace hopper 23 is discharged by the table feeder 33 and fed into a charge hopper or feeding hopper located below the discharge port 28. An example that meets the requirements of the present invention is one in which θ=73°, tan θ=3.3, and Pv=373 kgf / m 2 , s=0.25m 2 , L O =2m, (s / L O ) / L=0.04, and X=3.1 on the left side of equation (1).

[0049] As shown in Figure 6, the rake feeder 34 is provided at the opening 56 at the bottom end 55 of the storage hopper 21. An operating cylinder is provided on one side of the opening 56, and a sliding plate 341 is connected to the cylinder. A scraper plate 342 is provided on the sliding plate, and the surface of the sliding plate 341 facing forward is vertical, while the surface facing backward is inclined. The sliding plate 341 slides in conjunction with the forward and backward movement of the cylinder, sending waste plastic from the cylinder side of the opening 56 to the opposite side. This can be used when the bottom end 55 of the storage hopper has a large opening 56. An example that meets the requirements of the present invention is when θ=85°, tan θ=12, and Pv=1350 kgf / m 2 , s=12.3m 2 , L O =14m, (s / L O ) / L=0.055, and X>4 on the left side of equation (1) can be exemplified.

[0050] As shown in Figure 7, the apron feeder 35 has a feed conveyor 39 attached to the opening 56 at the bottom end 55 of the storage hopper 21. As the feed conveyor 39 operates, waste plastic can be moved. This can be used when the bottom end 55 of the storage hopper 21 has a large opening 56. An example that meets the requirements of the present invention is when θ=76°, tan θ=4, and Pv=784 kgf / m 2 , s=2.3m 2 , L O =6m, (s / L O ) / L=0.047, and the left side of equation (1) X>4 can be exemplified.

[0051] In the examples shown in Figures 8 and 9, a circle feeder 32 is used as a waste plastic feeder located at the lower end of the above-ground hopper 22, which is the storage hopper 21. In addition, a screw feeder 31 is used as a waste plastic feeder located at the lower end of the above-furnace hopper 23, which is the storage hopper 21, in the example shown in Figure 8, and a table feeder 33 is used in the example shown in Figure 9.

[0052] The waste plastic stored in the furnace hopper is supplied to a hopper installed on a coal loading car for loading waste plastic into the loading port of the carbonization chamber, and the waste plastic is loaded from the hopper into the carbonization chamber through the loading port of the carbonization chamber.

[0053] As shown in Figure 8, a dedicated waste plastic charging hopper 43 is installed on a coal car 41 or a mobile carriage, separate from the coal car 41, that can move in the furnace battery length direction. The same number of charging hoppers 43 are arranged in the furnace length direction of the coking chamber. Like the storage hopper 21 of the present invention described above, this charging hopper 43 also has a pyramidal or conical surface that contacts the waste plastic. The effects of the present invention can be achieved by setting the value of X on the left side of equation (1) above to a predetermined value or greater, with respect to the relationship between the hopper angle θ, the vertical stress Pv acting on the opening, and the cross-sectional area S of the opening / the perimeter L of the opening. The predetermined value of X on the left side of the equation is 2 or greater, preferably 2.5 or greater, and more preferably 3 or greater. This prevents waste plastic from clogging or hanging in the charging hopper. In the example shown in Figure 8, a screw feeder 31 is used as a waste plastic feeder located at the bottom end of a storage hopper 21 serving as a feeding hopper 43. In cases where the hopper angles θ formed by the surfaces constituting the storage hopper are different, it is sufficient that the value of X on the left side of equation (1) is within a preferred range at the position where the hopper angle θ is smallest.

[0054] As shown in Figure 9, a case will be described in which a charge hopper 42 for charging coal, which is provided on a coal car 41, is modified and used as a hopper for charging waste plastic into the charging port of the carbonization chamber. The conditions that the storage hopper 21 as the charge hopper 42 must satisfy are the same as those of the charging hopper 43 dedicated to charging waste plastic, which is provided on the coal car 41. In the example shown in Figure 9, a table feeder 33 is used as the cutting device located at the lower end of the charge hopper 42. [Explanation of symbols]

[0055] 1. Coke oven 2. Carbonization chamber 4 charging port 5 Furnace top space 11 Charging coal 12 Waste plastic 21 Storage Hopper 22 Ground Hopper 23 Furnace hopper 24 Cutting device 25 Flight Conveyor 26 Distribution cut-out device 28 Cutting edge 31 Screw feeder 32 Circle Feeder 33 Table Feeder 34 Rake Feeder 341 Sliding plate 342 Scraping board 35 Apron Feeder 36 Slats 37 Bottom plate 38 Opening 39 Feed conveyor 41 Coaling car 42 Charge Hopper 43 Feeding hopper 44 Reception Slope 45 tracks 51 sides 52 Horizontal plane 53 Orthogonal plane 54 Intersection line 55 Lower end 56 Aperture 57 Upper end

Claims

1. A waste plastic transport device for supplying waste plastic into a coke oven carbonization chamber through a charging port provided in a ceiling portion of the coke oven carbonization chamber, The waste plastic transport device has a waste plastic storage hopper in the middle of the transport route, and the storage hopper has a pyramidal or conical portion on a part thereof with which the waste plastic comes into contact, The lower end of the storage hopper is open, The vertical stress Pv (kgf / m) applied to the lower end of the storage hopper storing the waste plastic ２ ), tan θ calculated from the hopper angle θ (°) of the storage hopper, the cross-sectional area s (m ２ ), the peripheral length L of the opening Ｏ (m), the peripheral length L (m) of the upper end of the storage hopper, The relational expression representing the dischargeability performance index obtained by observing the dischargeability performance is the following formula (1), and the value of X, which is the calculation result obtained by substituting the performance value of tan θ into formula (1), is 2.00 or more, and (s / L Ｏ ) / L is 0.025 or more, Waste plastic transport equipment. X=1123907・(Pv) -1.55 ・(s / L O ) 2 ・(tanθ) 0.46 (1) In addition, when the surface that contacts the waste plastic is pyramidal, the hopper angle θ refers to the angle between the horizontal plane and a plane that is perpendicular to both the pyramidal surface and the horizontal plane, and when the surface is conical, the hopper angle θ refers to the angle between the horizontal plane and a plane that is perpendicular to any part of the surfaces that make up the cone and is perpendicular to the horizontal plane (hereinafter referred to as the "orthogonal plane"), and the horizontal plane. The hopper angle θ is the value at the position where the hopper angle is minimum on the surface that contacts the waste plastic.

2. 2. The waste plastic transport device according to claim 1, wherein the storage hopper comprises at least one of a ground hopper, a furnace hopper, an input hopper, and a charge hopper.

3. The waste plastic transport device described in claim 2, characterized in that a waste plastic feeder is arranged at the lower end of one or more of the ground hopper, furnace hopper, input hopper, and charge hopper, and the waste plastic feeder is one of a screw feeder, circle feeder, table feeder, rake feeder, and apron feeder.

4. A waste plastic storage hopper used in the waste plastic transport device according to claim 1.

5. A waste plastic storage hopper used in the waste plastic transport device according to claim 2.

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