Three-bin two-section type heat exchange crushing and mixing device and method

Abstract

The invention discloses a three-bin two-section type heat exchange crushing and mixing device and method.The device comprises a heat exchange section and a crushing section, a heat exchange separation device composed of three heat exchange screens is arranged in the heat exchange section, the heat exchange section is divided into three bins by the heat exchange separation device, and the three bins are the biomass bin, the coal bin and the ash bin respectively; the outlet end of the biomass bin and the outlet end of the coal bin are both communicated with the crushing section, and a flow guide plate is arranged at the outlet end of the ash bin and used for sealing the ash bin. According to the invention, unpretreated biomass and coal are indirectly heated by ash heat in a three-bin rotary kiln mode, the hot spot combustion problem and the subsequent separation problem caused by direct heating are avoided, the recycling of ash waste heat is realized, the unpretreated biomass is crushed by using the thermal brittleness effect, and the utilization rate of coal is improved. And heating, crushing and mixing are integrated in the same rotary kiln, so that the configuration of traditional equipment can be simplified, and the investment cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of biomass pretreatment, and in particular to a three-bin two-stage heat exchange crushing and mixing device and method. Background Art

[0002] Under the major strategic layout of "carbon peak and carbon neutrality", carbon emission reduction of traditional large-scale coal-fired units is imperative. Coal-fired units coupled with biomass power generation is one of the important means of carbon emission reduction, and it is also an effective means of treating large amounts of agricultural and forestry waste. There are generally two ways to directly burn biomass in coal-fired boilers: one is to set up a special burner. This method requires a major transformation of the original boiler, increasing the cost of the transformation, and the dedicated burner will change the flow field and component field in the furnace, affecting the combustion efficiency and pollutant emissions of the boiler. Another way is to add biomass fuel to the original coal burner. This method requires the biomass to be crushed into powder of the same particle size as the coal powder, but the biomass generally has a high water content and a soft shape, which is not easy to be cut by the high-speed rotating mechanical blades of conventional biomass crushing devices. If it is to be crushed into powder, it requires a lot of energy. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, a three-bin two-stage heat exchange crushing and mixing device is provided, which uses the heat of ash to indirectly heat the untreated biomass and coal through a three-bin rotary kiln, avoiding the hot spot combustion problem and subsequent separation difficulties caused by direct heating, and realizing the reuse of ash waste heat. At the same time, the thermal brittleness effect is used to crush the untreated biomass, and the heating, crushing and mixing are integrated in the same rotary kiln, which can simplify the configuration of traditional equipment and reduce investment costs.

[0004] Technical solution: To achieve the above-mentioned purpose, the present invention provides a three-bin two-stage heat exchange, crushing and mixing device, including a heat exchange section and a crushing section. A heat exchange partition device composed of three heat exchange screens is arranged in the heat exchange section, and the heat exchange partition device divides the heat exchange section into three bins, namely a biomass bin, a coal bin and an ash bin. The outlet ends of the biomass bin and the coal bin are both connected to the crushing section. A guide plate is arranged at the outlet end of the ash bin, and the guide plate is used to close the ash bin. The heat exchange partition device is used to transfer the heat of the ash bin to the biomass bin and the coal bin. The crushing section is used to realize the crushing and mixing of biomass and coal.

[0005] Furthermore, the heat exchange screen includes a serpentine tube and fins, the fins are welded to the gaps on the serpentine tube along the tube axis direction, the serpentine tube welded with the fins serves as a dividing screen between adjacent bins, the portion of the serpentine tube without the fins welded extends into a non-adjacent bin, and heat transfer oil is enclosed in the serpentine tube.

[0006] Furthermore, the heat exchange section and the crushing section are respectively a first rotary kiln and a second rotary kiln, and the first rotary kiln and the second rotary kiln are coaxially connected.

[0007] Furthermore, the first rotary kiln and the second rotary kiln are arranged to be inclined at 5 to 15 degrees with respect to the horizontal direction.

[0008] Furthermore, the axial cross-section of the biomass bin is a sector with a central angle of 120 to 150 degrees, and is composed of the first rotary kiln wall and two heat exchange screens, one of which is a partition between the biomass bin and the coal bin, and the other is a partition between the biomass bin and the ash bin, with one end along the axial direction being the inlet end and the other end being the outlet end.

[0009] Furthermore, the axial cross-section of the coal bunker is a sector with a central angle of 110 to 130 degrees, and is composed of the first rotary kiln wall and two heat exchange screens, one of which is a partition between the coal bunker and the biomass bunker, and the other is a partition between the coal bunker and the ash bunker, with one end along the axial direction being the coal inlet end and the other end being the outlet end.

[0010] Furthermore, the axial cross-section of the ash bin is a sector with a central angle of 100 to 120 degrees, and is composed of a first rotary kiln wall, two heat exchange screens and a guide plate, wherein one heat exchange screen is a partition screen between the ash bin and the biomass bin, and the other heat exchange screen is a partition screen between the ash bin and the coal bin, one end along the axial direction is a coal ash inlet end, and the other end is closed by a guide plate, and an ash outlet is arranged on the rotary kiln wall at this end.

[0011] Furthermore, 60-80% of the heat transfer oil is sealed in the serpentine tube.

[0012] Furthermore, a steel ball and an iron chain are arranged in the crushing section, one end of the iron chain is connected to the steel ball, and the other end is connected to the wall surface of the second rotary kiln.

[0013] The present invention also provides an operating method of a three-bin two-stage heat exchange crushing and mixing device, comprising: during operation, biomass, coal and ash enter the biomass bin, coal bin and ash bin from the inlet end respectively, and as the rotary kiln rotates slowly, the biomass, coal and ash move in the circumferential direction and toward the outlet end, at this time, the ash in the ash bin transfers heat to the heat exchange screen to heat the heat transfer oil therein, and as the heat transfer oil flows, the heat is transferred to the biomass and coal in the biomass bin and the coal bin through the heat exchange screen to remove moisture; the heated biomass and coal enter the crushing section from the outlet end D, and the ash is discharged from the outlet C; the biomass and coal entering the crushing section are crushed by the impact of the steel balls, and as the rotary kiln rotates, the two are mixed with each other, and after the crushing and mixing are completed, they leave the crushing section and enter the next process.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0015] 1. Biomass generally has a high water content and a soft shape, and is not easily cut by the high-speed rotating mechanical blades of conventional biomass crushing devices. The heat exchange mixing device of the present invention first dries the biomass to form a loose and crisp structure, and then uses steel balls to roll and crush it, which can greatly reduce the energy consumption of crushing.

[0016] 2. Existing biomass utilization devices generally use raw materials collected naturally. These biomasses have a high water content. Even if they are dried naturally, only part of the external water is removed. The heat exchange and mixing device of the present invention uses the waste heat of the hot slag to dry the biomass, which can greatly reduce the sensible heat loss of the subsequent utilization device.

[0017] 3. The two-stage three-chamber heat exchange and mixing device of the present invention indirectly heats biomass and coal through a three-chamber rotary kiln, avoiding the hot spot combustion problem and subsequent separation difficulties caused by direct heating. At the same time, heating, crushing and mixing are integrated in the same rotary kiln, which can reduce the number of equipment and greatly reduce the investment cost.

[0018] 4. The three-bin heat exchange device of the present invention not only exchanges heat through the heat exchange screens between the bins, but also exchanges heat between the materials in the bins through the serpentine tubes of the heat exchange screens. The serpentine tubes are not filled with heat transfer oil to enhance the heat exchange. This design increases the heat exchange area of ​​indirect heat exchange and enhances the heat exchange efficiency.

[0019] 5. The crushing section of the present invention can not only realize the crushing of biomass and coal, but also meet the mixing of coal powder and biomass particles. While simplifying the configuration of traditional equipment, it can also meet the material requirements of subsequent processes, greatly reducing the equipment investment cost.

[0020] 6. The present invention utilizes the thermal brittleness effect to crush the unpretreated biomass, which can improve the crushing efficiency of the biomass and reduce the pretreatment cost of the biomass. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the normal operating state of the device of the present invention;

[0022] Figure 2 is a longitudinal cross-sectional view of the device of the present invention;

[0023] Figure 3 It is a schematic diagram of the specific structure of the heat exchange screen in the present invention. DETAILED DESCRIPTION

[0024] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0025] Embodiment 1:

[0026] like Figure 1 and Figure 2 As shown, the present embodiment provides a three-bin two-stage heat exchange crushing and mixing device, including a heat exchange section and a crushing section, wherein the heat exchange section and the crushing section are respectively a first rotary kiln 1 and a second rotary kiln 2 which are coaxially connected, the first rotary kiln 1 and the second rotary kiln 2 are arranged at an inclination of 15° with the horizontal direction, a heat exchange partition device composed of three heat exchange screens 6 is arranged in the first rotary kiln 1, and the heat exchange partition device divides the first rotary kiln 1 into three bins, namely a biomass bin 7, a coal bin 8 and an ash bin 9, the outlet ends of the biomass bin 7 and the coal bin 8 are both connected to the second rotary kiln 2, a guide plate 5 is arranged at the outlet end of the ash bin 9, and the guide plate 5 is used to close the ash bin 9, a steel ball 4 and an iron chain 3 are arranged in the second rotary kiln 2, one end of the iron chain 3 is connected to the steel ball 4, and the other end is connected to the wall of the second rotary kiln 2,

[0027] Reference Figure 1 to Figure 3 The heat exchange screen 6 includes a serpentine tube 11 and fins 12. The fins 12 are welded to the gaps on the serpentine tube 11 along the tube axis direction. The serpentine tube 11 welded with the fins 12 forms a whole as a dividing screen 61 between adjacent bins. The portion of the serpentine tube 11 without the fins 12 welded thereto serves as an extension 62 extending into non-adjacent bins. 60% of the heat transfer oil 13 is enclosed in the serpentine tube 11.

[0028] The axial cross-section of the biomass bin 7 is a sector with a central angle of 120°, and is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen 61 between the biomass bin 7 and the coal bin 8, and the other is a partition screen 61 between the biomass bin 7 and the ash bin 9. One end along the axial direction is the biomass inlet end A, and the other end is the biomass outlet end D.

[0029] The axial cross-section of the coal bunker 8 is a sector with a central angle of 120°. It is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen between the coal bunker 8 and the biomass bunker 7, and the other is a partition screen 61 between the coal bunker 8 and the ash bunker 9. One end along the axial direction is the coal inlet end A, and the other end is the coal outlet end D.

[0030] The axial cross-section of the ash bin 9 is a sector with a central angle of 120°. It is composed of the wall of the first rotary kiln 1, two heat exchange screens 6 and a guide plate 5. One heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the biomass bin 7, and the other heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the coal bin 8. One end along the axial direction is the coal ash inlet end B, and the other end is closed by the guide plate 5. An ash outlet C is arranged on the rotary kiln wall at this end.

[0031] In this embodiment, the above three-bin two-stage heat exchange crushing and mixing device is applied as an example, and the specific operation method is as follows: during operation, biomass, coal and ash enter the biomass bin 7, coal bin 8 and ash bin 9 from the biomass inlet end A, coal inlet end A and ash inlet end B respectively. As the first rotary kiln 1 slowly rotates, the biomass, coal and ash move along the circumferential direction toward the outlet end. At this time, the ash in the ash bin 9 transfers heat to the three heat exchange screens 6, heating the heat transfer oil 13 therein. As the heat transfer oil 13 The heat is transferred to the biomass and coal in the biomass bin 7 and the coal bin 8 through the heat exchange screen 6 to remove moisture; the heated biomass and coal enter the second rotary kiln 2 from the biomass outlet D and the coal outlet D respectively, and the ash is discharged from the ash outlet C; the biomass and coal entering the second rotary kiln 2 are crushed by the impact of the steel balls 4, and as the second rotary kiln 2 rotates, the two are mixed with each other, and after being crushed and mixed to a certain extent, they leave the second rotary kiln 2 from the outlet E to enter the next process.

[0032] Embodiment 2:

[0033] like Figure 1 and Figure 2 As shown, the present embodiment provides a three-bin two-stage heat exchange crushing and mixing device, including a heat exchange section and a crushing section, wherein the heat exchange section and the crushing section are respectively a first rotary kiln 1 and a second rotary kiln 2 which are coaxially connected, the first rotary kiln 1 and the second rotary kiln 2 are arranged at an inclination of 15° with the horizontal direction, a heat exchange partition device composed of three heat exchange screens 6 is arranged in the first rotary kiln 1, and the heat exchange partition device divides the first rotary kiln 1 into three bins, namely a biomass bin 7, a coal bin 8 and an ash bin 9, the outlet ends of the biomass bin 7 and the coal bin 8 are both connected to the second rotary kiln 2, a guide plate 5 is arranged at the outlet end of the ash bin 9, and the guide plate 5 is used to close the ash bin 9, a steel ball 4 and an iron chain 3 are arranged in the second rotary kiln 2, one end of the iron chain 3 is connected to the steel ball 4, and the other end is connected to the wall of the second rotary kiln 2,

[0034] Reference Figure 1 to Figure 3 The heat exchange screen 6 includes a serpentine tube 11 and fins 12. The fins 12 are welded to the gaps on the serpentine tube 11 along the tube axis direction. The serpentine tube 11 welded with the fins 12 forms a whole as a dividing screen 61 between adjacent bins. The portion of the serpentine tube 11 without the fins 12 welded thereto serves as an extension 62, extending into non-adjacent bins. 80% of the heat transfer oil 13 is enclosed in the serpentine tube 11.

[0035] The axial cross-section of the biomass bin 7 is a sector with a central angle of 150°, and is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen 61 between the biomass bin 7 and the coal bin 8, and the other is a partition screen 61 between the biomass bin 7 and the ash bin 9. One end along the axial direction is the biomass inlet end A, and the other end is the biomass outlet end D.

[0036] The axial cross-section of the coal bunker 8 is a sector with a central angle of 110°. It is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen between the coal bunker 8 and the biomass bunker 7, and the other is a partition screen 61 between the coal bunker 8 and the ash bunker 9. One end along the axial direction is the coal inlet end A, and the other end is the coal outlet end D.

[0037] The axial cross-section of the ash bin 9 is a sector with a central angle of 100°. It is composed of the wall of the first rotary kiln 1, two heat exchange screens 6 and a guide plate 5. One heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the biomass bin 7, and the other heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the coal bin 8. One end along the axial direction is the coal ash inlet end B, and the other end is closed by the guide plate 5. An ash outlet C is arranged on the rotary kiln wall at this end.

[0038] In this embodiment, the above three-bin two-stage heat exchange crushing and mixing device is applied as an example, and the specific operation method is as follows: during operation, biomass, coal and ash enter the biomass bin 7, coal bin 8 and ash bin 9 from the biomass inlet end A, coal inlet end A and ash inlet end B respectively. As the first rotary kiln 1 slowly rotates, the biomass, coal and ash move along the circumferential direction toward the outlet end. At this time, the ash in the ash bin 9 transfers heat to the three heat exchange screens 6, heating the heat transfer oil 13 therein. As the heat transfer oil 13 The heat is transferred to the biomass and coal in the biomass bin 7 and the coal bin 8 through the heat exchange screen 6 to remove moisture; the heated biomass and coal enter the second rotary kiln 2 from the biomass outlet D and the coal outlet D respectively, and the ash is discharged from the ash outlet C; the biomass and coal entering the second rotary kiln 2 are crushed by the impact of the steel balls 4, and as the second rotary kiln 2 rotates, the two are mixed with each other, and after being crushed and mixed to a certain extent, they leave the second rotary kiln 2 from the outlet E to enter the next process.

[0039] Embodiment 3:

[0040] like Figure 1 and Figure 2 As shown, the present embodiment provides a three-bin two-stage heat exchange crushing and mixing device, including a heat exchange section and a crushing section, wherein the heat exchange section and the crushing section are respectively a first rotary kiln 1 and a second rotary kiln 2 which are coaxially connected, the first rotary kiln 1 and the second rotary kiln 2 are arranged at an inclination of 15° with the horizontal direction, a heat exchange partition device composed of three heat exchange screens 6 is arranged in the first rotary kiln 1, and the heat exchange partition device divides the first rotary kiln 1 into three bins, namely a biomass bin 7, a coal bin 8 and an ash bin 9, the outlet ends of the biomass bin 7 and the coal bin 8 are both connected to the second rotary kiln 2, a guide plate 5 is arranged at the outlet end of the ash bin 9, and the guide plate 5 is used to close the ash bin 9, a steel ball 4 and an iron chain 3 are arranged in the second rotary kiln 2, one end of the iron chain 3 is connected to the steel ball 4, and the other end is connected to the wall of the second rotary kiln 2,

[0041] Reference Figure 1 to Figure 3 The heat exchange screen 6 includes a serpentine tube 11 and fins 12. The fins 12 are welded to the gaps on the serpentine tube 11 along the tube axis direction. The serpentine tube 11 welded with the fins 12 forms a whole as a dividing screen 61 between adjacent bins. The portion of the serpentine tube 11 without the fins 12 welded thereto serves as an extension 62 extending into non-adjacent bins. 70% of the heat transfer oil 13 is enclosed in the serpentine tube 11.

[0042] The axial cross-section of the biomass bin 7 is a sector with a central angle of 130°, and is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen 61 between the biomass bin 7 and the coal bin 8, and the other is a partition screen 61 between the biomass bin 7 and the ash bin 9. One end along the axial direction is the biomass inlet end A, and the other end is the biomass outlet end D.

[0043] The axial cross-section of the coal bunker 8 is a sector with a central angle of 120°. It is composed of the wall of the first rotary kiln 1 and two heat exchange screens 6, one of which is a partition screen between the coal bunker 8 and the biomass bunker 7, and the other is a partition screen 61 between the coal bunker 8 and the ash bunker 9. One end along the axial direction is the coal inlet end A, and the other end is the coal outlet end D.

[0044] The axial cross-section of the ash bin 9 is a sector with a central angle of 110°. It is composed of the wall of the first rotary kiln 1, two heat exchange screens 6 and a guide plate 5. One heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the biomass bin 7, and the other heat exchange screen 61 is a partition screen 61 between the ash bin 9 and the coal bin 8. One end along the axial direction is the coal ash inlet end B, and the other end is closed by the guide plate 5. An ash outlet C is arranged on the rotary kiln wall at this end.

[0045] In this embodiment, the above three-bin two-stage heat exchange crushing and mixing device is applied as an example, and the specific operation method is as follows: during operation, biomass, coal and ash enter the biomass bin 7, coal bin 8 and ash bin 9 from the biomass inlet end A, coal inlet end A and ash inlet end B respectively. As the first rotary kiln 1 slowly rotates, the biomass, coal and ash move along the circumferential direction toward the outlet end. At this time, the ash in the ash bin 9 transfers heat to the three heat exchange screens 6, heating the heat transfer oil 13 therein. As the heat transfer oil 13 The heat is transferred to the biomass and coal in the biomass bin 7 and the coal bin 8 through the heat exchange screen 6 to remove moisture; the heated biomass and coal enter the second rotary kiln 2 from the biomass outlet D and the coal outlet D respectively, and the ash is discharged from the ash outlet C; the biomass and coal entering the second rotary kiln 2 are crushed by the impact of the steel balls 4, and as the second rotary kiln 2 rotates, the two are mixed with each other, and after being crushed and mixed to a certain extent, they leave the second rotary kiln 2 from the outlet E to enter the next process.

Claims

1. A three-bin two-stage heat exchange crushing and mixing device, characterized in that: It includes a heat exchange section and a crushing section. A heat exchange partition device composed of three heat exchange screens is arranged in the heat exchange section. The heat exchange partition device divides the heat exchange section into three bins, namely a biomass bin, a coal bin and an ash bin. The outlet ends of the biomass bin and the coal bin are both connected to the crushing section. A guide plate is arranged at the outlet end of the ash bin, and the guide plate is used to close the ash bin. The heat exchange partition device is used to transfer the heat of the ash bin to the biomass bin and the coal bin. The crushing section is used to realize the crushing and mixing of biomass and coal.

2. A three-bin two-stage heat exchange crushing and mixing device according to claim 1, characterized in that: The heat exchange screen includes a serpentine tube and fins, wherein the fins are welded to the gaps on the serpentine tube along the tube axis direction, and the serpentine tube welded with the fins serves as a dividing screen between adjacent bins, and the portion of the serpentine tube without the fins welded thereto extends into a non-adjacent bin, and heat transfer oil is enclosed in the serpentine tube.

3. A three-bin two-stage heat exchange crushing and mixing device according to claim 2, characterized in that: The heat exchange section and the crushing section are respectively a first rotary kiln and a second rotary kiln, and the first rotary kiln and the second rotary kiln are coaxially connected.

4. A three-bin two-stage heat exchange crushing and mixing device according to claim 3, characterized in that: The first rotary kiln and the second rotary kiln are arranged with an inclination of 5 to 15 degrees with respect to the horizontal direction.

5. The three-bin two-stage heat exchange crushing and mixing device according to claim 3 is characterized in that: The axial section of the biomass bin is fan-shaped, and is composed of the first rotary kiln wall and two heat exchange screens, one of which is a partition screen between the biomass bin and the coal bin, and the other is a partition screen between the biomass bin and the ash bin.

6. A three-bin two-stage heat exchange crushing and mixing device according to claim 3, characterized in that: The axial cross-section of the coal bunker is fan-shaped, and is composed of the first rotary kiln wall and two heat exchange screens, one of which is a partition screen between the coal bunker and the biomass bunker, and the other is a partition screen between the coal bunker and the ash bunker.

7. A three-bin two-stage heat exchange crushing and mixing device according to claim 3, characterized in that: The axial cross-section of the ash bin is fan-shaped, and is composed of the first rotary kiln wall, two heat exchange screens and a guide plate, wherein one heat exchange screen is a partition screen between the ash bin and the biomass bin, and the other heat exchange screen is a partition screen between the ash bin and the coal bin.

8. The three-bin two-stage heat exchange crushing and mixing device according to claim 2 is characterized in that: 60-80% of the heat transfer oil is sealed in the serpentine tube.

9. The three-bin two-stage heat exchange crushing and mixing device according to claim 2, characterized in that: A steel ball and an iron chain are arranged in the crushing section, one end of the iron chain is connected to the steel ball, and the other end is connected to the wall surface of the second rotary kiln.

10. An operating method of a three-bin two-stage heat exchange crushing and mixing device, characterized in that: include: During operation, biomass, coal and ash enter the biomass bin, coal bin and ash bin from the inlet end respectively. With the slow rotation of the rotary kiln, the biomass, coal and ash move circumferentially and toward the outlet end. At this time, the ash in the ash bin transfers heat to the heat exchange screen to heat the heat transfer oil therein. With the flow of the heat transfer oil, the heat is transferred to the biomass and coal in the biomass bin and coal bin through the heat exchange screen to remove moisture. The heated biomass and coal enter the crushing section from the outlet end D, while the ash is discharged from the outlet C. The biomass and coal entering the crushing section are crushed by the impact of the steel balls. With the rotation of the rotary kiln, the two are mixed with each other. After crushing and mixing, they leave the crushing section and enter the next process.

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