An apparatus for continuously drying rod-shaped biomass bales of different shapes and sizes

Abstract

The present invention relates to a device for continuously drying rod-shaped biomass bales of different shapes and sizes. It can continuously dry biomass bales of different shapes and sizes with waste flue gas or hot air and remove dust from the waste flue gas. Bales of different specifications can be placed on the slideway (3) of the drying channel (7). It has an upward-opening channel (16) to press the pressurized waste flue gas (30) or hot air (41) into the biomass bales. An air cushion (27) can be formed between the waste flue gas (30) or hot air (41) and the biomass bales to reduce the effective weight of the biomass bales. The slideway (3) uses polytetrafluoroethylene plates to reduce the thrust required to push the bales. The bale pusher shield (2) can adjust the angle to facilitate the feeding operation of the forklift. The rapid mixing of the hot flue gas (37) and fresh air (38) through the gas mixing tower (36) can prevent the resynthesis of dioxins. The device of the present invention can also be used for drying round bales of feed and forage, etc.

Description

Technical Field

[0001] The present invention relates to the design and construction of a device for continuously drying rod-shaped biomass bales of different shapes and sizes. This device is used for continuously drying whole round or square bales of straw, and for dust removal of the waste flue gas from the combustion system that is used to dry the straw bales. It can also dry, at low cost, for example, protein-rich green plant feeds for raising animals, etc. Background Art

[0002] In the fully automatic drying device for drying straw bales using the waste flue gas from the tail of the combustion system according to Patent CH202010683508.01, only round bales are preferably used during the drying operation, and they are transported through the drying channel by a chain-driven conveying device. Looking from the side, the waste flue gas from the tail of the combustion system blows horizontally across the bales. Therefore, special devices must be used to horizontally press the round straw bales onto the fixed air supply holes, which requires a relatively large waste flue gas pressure and a complex process. Moreover, when there are large deviations in the size of the straw bales, operators need to intervene.

[0003] The chain-driven conveying system includes support pipes, support rollers, bearings, etc. that are easily corroded. Round bales or square bales of different sizes cannot be dried simultaneously. During the movement of the bales, the waste flue gas may pass through between two round bales without being filtered by the round straw bales, thus affecting the flue gas dust emission value.

[0004] Drying energy consumption for making animal feeds from protein-rich green plants, etc. is relatively large. Currently, no devices or equipment have been seen that use the device for drying straw bales to dry green plants, etc. Summary of the Invention

[0005] The object of the present invention is to invent a drying device for whole bales of rod-shaped biomass that can operate continuously. This device only contains a small number of moving and easily corroded metal components, and can dry round bales or square bales of different specifications as needed at any time without any modification to the device or intervention by operators. The number of bales for drying and dust removal can be increased, and at the same time, the amount of hot flue gas blown through or passing through the biomass bales can be minimized as much as possible. This device can also be used to dry bales of green plants, etc. as needed.

[0006] The present invention is realized through a drying channel. In this drying channel, many whole bales of biomass of different specifications and shapes, lying flat on the ground, are arranged adjacent to each other continuously on a horizontal or inclined chute and are pushed forward from the back. In the drying channel, there is a channel opening longitudinally upward that blows pressurized hot flue gas into the biomass bales in the opposite direction of gravity.

[0007] The pressurized waste flue gas in the drying channel generates an upward thrust on the straw bale, creating an air cushion between the slideway and the biomass bale, and reducing the propulsion force required for the straw bale to move on the track.

[0008] The slideway material for the forward propulsion of the straw bale in the drying channel can be selected as a material with a very low surface sliding friction coefficient. The preferred material is a polytetrafluoroethylene plate with a certain thickness. In the present invention, the polytetrafluoroethylene plates are stacked on top of each other and arranged like fish scales.

[0009] The propulsion force of the biomass bale pusher shield in the drying channel causes two similar circular biomass bales to squeeze against each other, resulting in a certain degree of deformation of the cross-section where the two bales come into contact. In this way, the upward-opening waste flue gas channel will be densely covered by the biomass bales, ensuring sufficient airtightness.

[0010] The propulsion force required for the deformation of the contact surface between adjacent biomass bales is structurally determined by the number of biomass bales and the inclination of the slideway. For example, if the slideway is lifted from a horizontal position to a maximum elevation angle of 45°, a greater propulsion force is required to deform the contact surface of the biomass bales; if the slideway is horizontally lowered to a depression angle of 3°, the required propulsion force can be reduced. The device according to the present invention can be designed to handle different numbers of biomass bales.

[0011] If the slideway is horizontally lowered to a depression angle greater than 5°, a downward self-sliding force will be generated on the biomass bales on the slideway, reducing the thrust required for the biomass bale pusher shield. In this way, a long drying channel can be established to handle more biomass bales.

[0012] The cross-section of the hot flue gas supply channel with an upward opening for providing pressurized hot flue gas in the present invention is designed as an inverted trapezoid or triangle to reduce or avoid dust deposition, thus facilitating the formation of an air cushion between the slideway with a polytetrafluoroethylene plate fish-scale structure and the biomass bale.

[0013] The device according to the present invention includes a hot flue gas supply channel for pressurized hot flue gas arranged longitudinally along the drying channel and below the biomass bales. The cross-section of the supply channel of the present invention is designed as an inverted trapezoid or triangle, and the inverted trapezoid or triangle reduces or avoids dust deposition, thus facilitating the formation of an air cushion between the slideway with a preferred polytetrafluoroethylene plate fish-scale structure in the present invention and the biomass bales. The device of the present invention is designed such that the flow rate of the hot flue gas in the hot flue gas supply channel is greater than 10 m / s to reduce or avoid dust accumulation.

[0014] The dust accumulated at the bottom will be carried away by the air supply pipe spaced at a certain distance and connected to the hot flue gas supply channel. The cross-sectional dimension of the air supply pipe is designed to achieve an air supply flow rate of more than 10 m / s to reduce or avoid dust deposition here.

[0015] To ensure that the biomass bale is always inserted obliquely from above along the longitudinal direction into the feeding port of the device of the present invention, the pivot shaft of the bale pusher shield is installed in the guiding bodies with pulleys that can slide or roll in the steel troughs on both sides of the channel.

[0016] The bale pusher shield at the terminal of the biomass bale feeding port is in an inclined position to reduce the operating space required for the forklift.

[0017] To enable the device of the present invention to be used at any time for drying green plants, etc., the device of the present invention is also designed with a gas mixing tower with a throttle valve for quickly mixing fresh air and hot flue gas to generate hot air for drying. By quickly mixing, the hot flue gas is rapidly cooled, thus reliably preventing the resynthesis of dioxins. Description of the Drawings

[0018] Figure 1 The device according to the present invention is shown in a longitudinal sectional view.

[0019] Figure 2 A cross-section of the device according to the present invention with a hot flue gas supply channel (and supply duct) is shown.

[0020] Figure 3 The biomass bale filling station and the rotatable bale pusher shield are shown in a longitudinal sectional view.

[0021] Figure 4 The scaly arrangement of the polytetrafluoroethylene plates on the slideway is shown.

[0022] Figure 5 A top view of the biomass round bale deformed by the thrust is shown.

[0023] Figure 6 The relationship between the slideway, the pressurized hot flue gas and the air cushion is shown in a cross-sectional view.

[0024] Figure 7 A top view shows the thermal system with four gasification combustion modules of the device of the present invention.

[0025] Figure 8 The gas mixing tower is shown.

[0026] In the figure: 1 - Bale feeding bin, 2 - Bale pusher shield, 3 - Slideway, 4 - Biomass round bale, 5 - Biomass square bale, 6 - Rolling shaft, 7 - Drying channel, 8 - Straw bale pushing gate, 9 - Guide body, 10 - Steel trough, 11 - Chain, 12 - Anchor chain bin, 13 - Slide rail, 14 - Hot flue gas supply channel, 15 - Air supply pipe, 16 - Channel with upward opening, 17 - Forklift truck, 18 - Conveyor chain drive, 19 - Stroke limiter, 20 - Fabric curtain, 21 - Bale transmission direction, 22 - Polytetrafluoroethylene plate, 23 - Steel beam, 24 - Steel plate, 25 - Metal strip, 26 - Countersunk screw, 27 - Air cushion, 28 - Effective action cross-section, 29 - Maximum flow cross-section, 30 - Waste flue gas, 31 - Operating whole bale straw gasification device, 32 - Stopped whole bale straw gasification device, 33 - Converging post-combustion device, 34 - Dust removal device, 35 - Fan, 36 - Gas mixing tower, 37 - Hot flue gas, 38 - Fresh air, 39 - Throttle valve, 40 - Induced draft fan, 41 - Hot air, 42 - Second post-combustion device, 43 - Heat exchanger, 44 - Main induced draft fan, 45 - Dried bale, 46 - Spring, 47 - Insert rod corner shaft, 48 - Pushing station, 49 - Shaft of bale pusher shield, 50 - Small biomass square bale. Detailed implementation mode

[0027] The present invention will be explained in more detail below using an embodiment.

[0028] According to Figure 1 The nearly sealed drying channel (7) for biomass round bales (4) and biomass square bales (5) is about 30 m long. A row can accommodate up to 25 biomass round bales (4) with a maximum diameter of 1.4 m continuously. Two rows of biomass bales arranged side by side can process up to 50 biomass round bales (4) at the same time. The two rows of the bale feeding bin (1) can also accommodate 6 - 10 biomass round bales (4) without blowing in hot flue gas.

[0029] In the bale feeding bin (1), biomass square bales (5) with a length not exceeding 2.4 m can also be added simultaneously with biomass round bales (4) and discharged mixed on the slideway (3). Small biomass square bales (50) can also be inserted horizontally by hand or using suitable tools.

[0030] According to Figure 2 As shown, the bale pusher shield (2) is integrally connected with a shaft (49) of a bale pusher shield. Both ends of the shaft (49) of the bale pusher shield are installed in the guide body (9) pulled by the chain (11) and slide in the steel trough (10). The shaft (49) of the bale pusher shield together with the bale pusher shield (2) can move back and forth in the drying channel (7). The biomass round bales (4) and biomass square bales (5) slide on the slideway (3) under the push of the bale pusher shield (2). A pair of longitudinal slide rails (13) can correct the position of the biomass bales in the vertical direction of the slide rails.

[0031] The hot flue gas supply channel (14) is arranged below the slideway (3). The size of its cross-section is designed such that the flow rate of the hot flue gas is greater than 10 m / s, which can prevent the accumulation of dust.

[0032] The cross-section of the hot flue gas supply channel (14) being in an inverted trapezoid or triangular shape is conducive to concentrating dust therein. When the hot air (41) is pressed into the air supply pipe (15) from the hot flue gas supply channel (14) at a speed greater than 10 m / s, it will also carry away a considerable part of the dust accumulated at the bottom of the hot flue gas supply channel (14). The air supply pipes (15) longitudinally connected to the hot flue gas supply channel (14) along the slideway (3) are spaced approximately 80 cm apart from each other at equal intervals in this embodiment.

[0033] As Figure 3 shown, the biomass round bale (4) is obliquely inserted into the bale feeding bin (1) from above by the lifting forklift (17) along the bale transmission direction (21). The bale pusher shield (2) is in an inclined position at an angle greater than approximately 55° with the horizontal direction when it is at the last station of the bale feeding bin (1). The biomass round bale (4) only needs to be lifted by the lifting forklift (17) and then the swivel angle shaft (47) of the forklift's insertion rod is rotated to turn it over and insert it into the bale feeding bin (1), and the flat side of the biomass round bale (4) is placed on the slideway (3).

[0034] When the bale pusher shield (2) returns to the last station of the bale feeding bin (1), it will be held in an inclined position by the stroke limiter (19) located at the bottom of the bale feeding bin (1), and the conveyor chain driver (18) located at the top of the bale feeding bin (1) presses the bale pusher shield (2) against the spring (46) located at the top. When the bale pusher shield (2) moves again along the bale transmission direction (21), it will first act due to the pressure of the spring (46) at the top and push the biomass round bale (4) that has not been fully aligned. When the bale pusher shield (2) reaches the pushing station (48), it will be at a right angle to the horizontal direction again and adapted to the contact surface shape of the biomass round bale (4) to achieve a good distribution of the driving force.

[0035] The biomass square bale (5) can also be inserted diagonally from above using a simple insertion rod by utilizing the swivel angle shaft (47).

[0036] In this embodiment, according to the size design of the device of the present invention, it is designed to accommodate a biomass round bale (4) with a maximum diameter of 1.40 m or a biomass square bale (5) with a maximum height and width of 1.20 m and a maximum length of 2.40 m. The seal between the slideway (3) and the biomass bale is achieved by the weight of the straw bale itself.

[0037] The inlet of the drying channel (7) can be closed by a heavier fabric curtain (20). By changing the speed of the fan (not shown in the figure) of the hot flue gas, the negative pressure in the drying channel (7) can be minimized and just sufficient to prevent the hot flue gas from escaping and the fabric curtain (20) is airtight enough.

[0038] The biomass bale slides on the chute (3). In this embodiment, the surface of the chute (3) is composed of a polytetrafluoroethylene plate (22). When constructing, the polytetrafluoroethylene plates stacked in a fish scale structure are fixed to the steel plate (24).

[0039] Figure 4 As shown, the polytetrafluoroethylene plate (22) is fixed to the steel plate (24) which is also stacked in a fish scale structure by using a 5-mm-thick metal strip (25) and countersunk screws (26) of this embodiment.

[0040] According to Figure 5 As shown, due to the thrust of the bale pusher shield (2), the biomass round bale (4) will be deformed. This deformation can completely cover the top opening of the upward-opening channel (16) (width 25 cm in this embodiment) with the biomass round bale (4) to achieve sealing.

[0041] According to Figure 6 As shown, the pressurized waste flue gas (30) and hot air (41) blown into the biomass bale from below can achieve the drying of the biomass bale and the dust removal of the waste flue gas (30). The waste flue gas (30) and hot air (41) will form an air cushion (27) between the biomass bale and the chute (3).

[0042] When the pressure of the waste flue gas (30) and hot air (41) in the upward-opening channel (16) with an inverted trapezoid or triangular cross-section reaches 1300 Pa, the downward gravity of the 200-kg biomass round bale (4) will be reduced by about 100 kg to only about 100 kg (about 1 kN). If there are 25 biomass round bales (4) of about 200 kg in the horizontally placed drying channel (7), then their effective total downward gravity is only 2500 kg (about 10 kN). When the friction coefficient of the polytetrafluoroethylene plate is about 0.04, the thrust required for this row of 25 biomass round bales (4) is only 100 kg (about 1 kN), which is only half of the normal total weight of the biomass round bales (4).

[0043] When there are 25 biomass square bales (5) weighing approximately 480 kg, with a height and width of approximately 1.2 m and a length of 2.4 m in the horizontally placed drying channel (7), when emptying the 25 biomass square bales (5) in the drying channel without the action force of the air cushion (27), the theoretical thrust required when the friction coefficient of the polytetrafluoroethylene plate is approximately 0.04 is only about 480 kg (4.8 kN), and this is only equivalent to the normal weight of one biomass square bale. And obtaining such a thrust only requires the bale pusher shield to push from the bale feeding bin (1).

[0044] For a small system that only processes a small number of biomass round bales (4), it is necessary to raise the chute (3) so that when the bale pusher shield pushes the biomass round bale (4) upward, it interacts with the gravity of the biomass round bale (4) to ensure that the biomass round bale (4) undergoes sufficient deformation strength.

[0045] For a larger device that processes a larger number of biomass bales, the thrust of the bale pusher shield can be reduced by designing the chute (3) at a downward angle. The upward inclination angle of the chute (3) to increase the thrust and the downward inclination angle to reduce the thrust can be determined by calculation according to the weight of the straw bales, etc. In this embodiment, the upward inclination angle of the chute (3) to increase the thrust and the downward inclination angle to reduce the thrust are 3° maximum and 5° minimum respectively.

[0046] In this embodiment, after the waste flue gas (30) and hot air (41) are sent out from the upward-opening channel (16) at a speed of approximately 0.18 m / s, after passing through Figure 6 the effective action cross-section (28) therein, the flow rate of the waste flue gas (30) and hot air (41) will decrease to below approximately 0.07 m / s. When passing through Figure 6 the maximum flow cross-section (29) part therein, the flow rate will continue to decrease. And when the waste flue gas (30) and hot air (41) are distributed over a larger number of biomass bales, the flow rate will be even lower, and both the pressure loss and the energy consumption of the fan (35) will be very small.

[0047] Moreover, the lower the flow rate of the waste flue gas (30) and hot air (41) passing through the biomass bales, the higher the degree of dust separation of the waste flue gas (30) and hot air (41), and the more biomass bales there are, the better the dust removal effect will be. The device of the present invention realizes a method for cleaning dust in the flue gas discharged from biomass with simple technologies and methods.

[0048] Figure 7The designed thermal output of the 4 complete straw gasification devices is approximately 30 megawatts. When only one operating complete straw gasification device (31) is in operation, the thermal output will decrease to 3 - 5 megawatts to produce energy. The drying channels (7) of the other three non-operating complete straw gasification devices (32) can be filled with a total of 150 biomass round bales (4) of feed, forage, etc. that need to be dried. Using the rapid drying technology device of the present invention can avoid the protein loss caused by microorganisms, etc. during the natural drying process of these feeds and forages during long-term storage in the field.

[0049] Figure 7 When the only operating complete straw gasification device (31) shown in the figure operates to produce hot air (41) during the non-heating season, for this purpose, a part of the hot flue gas (37) is sucked out from the converging post-combustion chamber (33) through an opening and mixed with 7 - 8 parts of fresh air (38) in a gas mixing tower (36) to a temperature of about 110 - 120 °C for drying biomass bales such as feed and forage.

[0050] Behind the drying channel (7) is a straw bale pushing gate (8), and the straw bale pushing gate (8) is designed according to CN202010683508.1. A rolling shaft (6) is arranged and installed here to send the straw bale along the vertical direction of the drying channel (7) through the straw bale pushing gate (8) to send out the dried bale (45).

[0051] Figure 8 An additional device - a gas mixing tower (36) for directly producing hot air (41) is shown. The converging post-combustion device (33) includes a device conforming to ZL201822279196.9 for eliminating the production of dioxins and furan compounds. By rapidly cooling the fresh air (38) and the hot flue gas (37) from about 900 °C in a cliff-like manner in the gas mixing tower (36), the regeneration of dioxins can be prevented, thus ensuring the safety of the drying of feed and forage dry matter.

[0052] Through Figure 8 The throttle valve (39) in can adjust the fresh air (38) to set the negative pressure in the gas mixing tower (36) and suck out the hot flue gas (37) from the converging vortex post-combustion chamber (33) through a draft fan (40). The hot air (41) after the fresh air (38) is mixed with the hot flue gas (37) is Figure 7 The fan (35) shown sucks it into the dust removal device (34) and then is pressed into the hot flue gas supply channel (14) and transferred to the biomass bale for drying feed, forage, etc. or drying fuel for the operating complete straw gasification device (31).

[0053] During the non-heating season, hot air (41) that can be used in drying devices (not shown) for feed, forage, grains, etc. can be produced via the gas mixing tower (36), or during the heating season, when heating operations are carried out, the production of hot air (41) that can be used in drying devices (not shown) for feed, forage, grains, etc. via the gas mixing tower can enable the device of the present invention to achieve better economic benefits in use.

Claims

1. An apparatus for continuously drying rod-shaped biomass bales of different shapes and sizes, comprising a horizontal or inclined, airtight drying channel (7) for conveying stalk-like biomass bales of different shapes and sizes fed from a bale feeding bin (1) and blown with pressurized waste flue gas or hot air; characterized in that, In the drying channel (7), biomass round bales (4) and biomass square bales (5) with different shapes and sizes are connected in rows one after another. These biomass bales are placed on the slideway (3) of the drying channel (7) with their planes, and are pushed by the bale pusher shield (2) and squeezed by adjacent biomass bales to show a certain degree of deformation. In the middle part of the slideway (3) of the drying channel (7) longitudinally, there is an upward-opening channel (16) to supply pressurized waste flue gas (30) or hot air (41) in the opposite direction of gravity. The slideway (3) is covered with polytetrafluoroethylene plates (22) that overlap each other like fish scales. The upward-opening channel (16) has an inverted trapezoid-like or triangle-like cross-section. The hot flue gas supply channel (14) has an inverted trapezoid-like or triangle-like cross-section, and its size is designed such that the flow rate of the hot flue gas in the hot flue gas supply channel (14) is greater than 10 m / s. The hot flue gas supply channel (14) is connected to the upward-opening channel (16) through a plurality of air supply pipes (15), and the cross-sectional size of the air supply pipes (15) is designed such that the flow rate of the pressurized hot flue gas in the air supply pipes (15) is greater than 10 m / s. The entrance of the drying channel (7) is closed by a heavier fabric curtain (20). By changing the fan speed of the hot flue gas, the negative pressure in the drying channel (7) is minimized and is just sufficient to prevent the hot flue gas from escaping and the fabric curtain (20) is tightly sealed enough. The pressurized waste flue gas (30) and hot air (41) blown into the biomass bales from below achieve the drying of the biomass bales and the dust removal of the waste flue gas (30). The waste flue gas (30) and hot air (41) form an air cushion (27) between the biomass bales and the slideway (3).

2. The device for continuously drying rod-shaped biomass bales of different shapes and sizes according to claim 1, characterized in that, The slideway (3) is arranged horizontally, or raised to a maximum elevation angle of 45°, or horizontally lowered to a depression angle of 3° to reduce the thrust for conveying the biomass bales, or horizontally lowered to a depression angle greater than 5° for the thrust of conveying the biomass bales only by gravity.

3. The device for continuously drying rod-shaped biomass bales of different shapes and sizes according to claim 1, characterized in that, Both ends of the shaft (49) of the bale pusher shield (2) are installed in the guide body (9) pulled by the chain (11) and slide in the steel groove (10), and the bale pusher shield (2) is kept inclined by a stroke limiter (19) at the end of the bale feeding bin (1).

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