Two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water

Abstract

The present invention belongs to the technical field of biomass pyrolysis gasification wastewater treatment and discloses a two-stage dissolved air four-phase separation vortex flotation tower for biomass pyrolysis gas washing water. The tower comprises a housing, an exhaust port, a conical bucket, a primary dissolved air water inlet, a heavy oil discharge port, a clean water discharge port, a light oil discharge port, a vortex forming component, a secondary dissolved air water inlet, an annular distributor, an oil collecting tank, a primary separation cylinder, and a secondary separation cylinder. The present invention achieves efficient four-phase separation of oil phase and water phase, liquid phase and gas phase, light oil phase and heavy oil phase, and light oil phase and water phase through two-stage flotation, thereby improving the flotation separation effect of the washing water and further realizing the recycling of the washing clean water.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass pyrolysis gasification wastewater treatment, and relates to a two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water. Background Art

[0002] During biomass pyrolysis and gasification, the pyrolysis gas contains a large amount of oily components, various organic acids, various combustible gas components, and carbon ash dust. These components often need to be recycled, but they are often mixed together and difficult to separate. If the pyrolysis gas is directly cooled using a conventional condenser, the oily components in the pyrolysis gas will adhere to the equipment surface, where they will accumulate and eventually block the gas flow space. If the biomass pyrolysis gas is washed with clean water, the organic acids in the pyrolysis gas will dissolve in the water to form wood vinegar; the oily phase is insoluble in water, and the combustible gases are washed and recycled for combustion. However, because the oily phase is mixed with light and heavy oil components, the light oily components are relatively easy to separate, while the heavy oil components have a density close to that of water, making it difficult to achieve a good oil-water separation. This results in a high oil content in the water, making it impossible to recycle the wash water, which in turn increases the difficulty of process water treatment and water consumption.

[0003] Traditional dissolved air vortex flotation devices use a pair of pipelines installed on the side of the cylinder to spray water to form a vortex effect. However, the mixing effect of dissolved air water and sewage is poor, the probability of contact between microbubbles and the oil phase is reduced, and the separation effect of the phases is not ideal.

[0004] Therefore, a suitable separation device is developed to achieve better separation of the light oil phase, heavy oil phase, water phase and gas phase of biomass pyrolysis gas washing water. Summary of the Invention

[0005] The purpose of the present invention is to provide a two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water. Through the two-stage flotation, the four-phase efficient separation of oil phase and water phase, liquid phase and gas phase, light oil phase and heavy oil phase, and light oil phase and water phase is achieved, thereby improving the flotation separation effect of the washing water.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a two-stage dissolved air four-phase separation vortex flotation tower for biomass pyrolysis gas washing water, comprising a shell, an exhaust port, a conical bucket, a first-stage dissolved air water inlet, a heavy oil discharge port, a clean water discharge port, a light oil discharge port, a vortex forming component, a second-stage dissolved air water inlet, an annular distributor, an oil collecting tank, a first-stage separation cylinder and a second-stage separation cylinder;

[0008] The exhaust port is arranged at the upper end of the shell, and the conical bucket is arranged at the lower end of the shell; the first-level dissolved air water inlet is arranged at the junction of the shell and the conical bucket, and the first-level dissolved air water inlet is connected to the vortex forming component located inside the first-level separation cylinder;

[0009] The first-stage separation cylinder is connected to the lower part of the second-stage separation cylinder, the lower part of the first-stage separation cylinder is fixed to the conical bucket, and there is a gap between the first-stage separation cylinder, the second-stage separation cylinder and the shell;

[0010] The secondary dissolved air water inlet is arranged in the middle of the shell and is connected to the annular distributor surrounding the outside of the secondary separation cylinder;

[0011] The oil collecting tank is located in the secondary separation cylinder and the upper end is fixed to the shell, and the lower end of the oil collecting tank is connected to the light oil discharge port;

[0012] The clean water discharge port and the light oil discharge port are arranged at the lower part of the shell, and the clean water discharge port is located above the light oil discharge port;

[0013] The heavy oil discharge port is arranged below the conical bucket.

[0014] In one technical solution, the vortex forming component includes a plurality of arc-shaped water outlet pipes and ribs, one end of each water outlet pipe is a trumpet-shaped nozzle, and each section of the water outlet pipe is connected end to end through a rib to form a ring.

[0015] In one technical solution, a heavy oil collector is provided inside the conical bucket, and a cross plate is fixed inside the cone. The cross plate passes through the heavy oil collector and one end of the cross plate is fixed to the conical bucket.

[0016] In one technical solution, the cross section of the heavy oil collector is a trapezoid that is narrow at the top and wide at the bottom.

[0017] In one technical solution, the upper end of the first-stage separation cylinder shrinks inward, and the upper end of the second-stage separation cylinder expands outward.

[0018] In one technical solution, a plurality of support plates are symmetrically connected to the outer side of the upper end of the oil collecting tank, and one end of the support plate is fixed to the shell.

[0019] In one technical solution, a flushing port is also provided on the conical bucket.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides a primary separation cylinder and a vortex-forming assembly, utilizing vortex flow to separate the light oil phase from the heavy oil phase at the primary separation cylinder. A secondary separation cylinder and an annular distributor are provided to cause unseparated heavy oil in the upper wash water to descend again due to disturbance, thereby achieving deep treatment of the wash water. An oil collection tank is provided, allowing the rising light oil phase and the water phase to naturally separate due to density differences, overflowing into the oil collection tank as the light oil phase increases, thereby achieving separation of the light oil phase and the water phase. The present invention utilizes secondary flotation to achieve efficient separation of four phases: oil phase and water phase, liquid phase and gas phase, light oil phase and heavy oil phase, and light oil phase and water phase, thereby improving the flotation separation effect of the wash water and further enabling the recycling of the clean wash water. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a three-dimensional schematic diagram of the vortex flotation tower of the present invention.

[0023] Figure 2 This is a schematic diagram of the main structure of the vortex flotation tower of the present invention.

[0024] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA axis.

[0025] Figure 4 It is a schematic structural diagram of the primary separation cylinder and the secondary separation cylinder of the vortex flotation tower of the present invention.

[0026] Figure 5 It is a structural schematic diagram of the oil collecting tank of the vortex flotation tower of the present invention.

[0027] Figure 6 It is a structural schematic diagram of the vortex forming component of the vortex flotation tower of the present invention.

[0028] Markings in the accompanying drawings: 1 is the shell, 2 is the exhaust port, 3 is the conical bucket, 4 is the first-level dissolved air water inlet, 5 is the flushing port, 6 is the heavy oil discharge port, 7 is the clean water discharge port, 8 is the light oil discharge port, 9 is the vortex forming component, 9-1 is the nozzle, 9-2 is the water outlet pipe, 9-3 is the rib plate, 10 is the second-level dissolved air water inlet, 11 is the annular distributor, 12 is the support plate, 13 is the oil collecting tank, 15 is the heavy oil collector, 16 is the first-level separation cylinder, 17 is the second-level separation cylinder, and 18 is the cross plate. DETAILED DESCRIPTION

[0029] The following examples are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0030] Example 1

[0031] like Figures 1 to 3As shown, a two-stage dissolved air four-phase separation vortex flotation tower for biomass pyrolysis gas washing water includes a shell 1, an exhaust port 2, a conical bucket 3, a first-stage dissolved air water inlet 4, a heavy oil discharge port 6, a clean water discharge port 7, a light oil discharge port 8, a vortex forming component 9, a second-stage dissolved air water inlet 10, an annular distributor 11, an oil collecting tank 13, a first-stage separation cylinder 16 and a second-stage separation cylinder 17.

[0032] The exhaust port 2 is provided at the upper end of the shell 1, and the conical bucket 3 is provided at the lower end of the shell 1; the first-level dissolved air water inlet 4 is provided at the junction of the shell 1 and the conical bucket 3, and the first-level dissolved air water inlet 4 is connected to the vortex forming component 9 located inside the first-level separation cylinder 16. Figure 6 As shown, in this example, the vortex forming component 9 includes multiple arc-shaped water outlet pipes 9-2 and ribs 9-3, one end of each water outlet pipe 9-2 is a trumpet-shaped nozzle 9-1, and each section of the water outlet pipe 9-2 is connected end to end through four ribs 9-3 to form a ring, and there is a gap between each rib 9-3. In this way, before the separation operation begins, the washing water from the pyrolysis and gasification of biomass first enters the flotation tower from the first-level dissolved air water inlet 4, and then the first-level dissolved air water enters the outlet pipe 9-2 through the first-level dissolved air water inlet 4 to the trumpet-shaped nozzle 9-1. Suction is formed at the nozzle 9-1, and the washing water is sucked in from the gap between the nozzle 9-1 and the rib plate 9-3. The washing water is then mixed with the continuously introduced dissolved air water to form a jet mixed water flow, and then a vortex field is formed inside the first-level separation cylinder 16. The microbubbles in the washing water carry the light oil and continue to rise. The vortex accelerates the heavy oil to sink and be collected at the conical bucket 3, thereby realizing the vortex flotation separation of the light oil phase and the heavy oil phase at the first-level separation cylinder 16.

[0033] like Figure 3 As shown, in the present invention, the first-stage separation cylinder 16 is connected to the lower part of the second-stage separation cylinder 17, and the first-stage separation cylinder 16 is fixed to the conical bucket 3 below. There is a gap between the first-stage separation cylinder 16, the second-stage separation cylinder 17 and the shell 1 to ensure that the washing water and the light oil phase can fill the interior of the flotation tower. The second-stage dissolved air water inlet 10 is set in the middle of the shell 1 and is connected to the annular distributor 11 surrounding the outside of the second-stage separation cylinder 17. The inner side of the annular distributor 11 is fixed to the outer side of the second-stage separation cylinder 17 through a fixed plate. In this way, after the heavy oil phase is separated, the light oil phase and the water phase enter the second-stage separation cylinder 17, and the second-stage dissolved air water enters the flotation tower through the second-stage dissolved air water inlet 10. The dissolved air water is sprayed out through the water outlet provided on the annular distributor 11, forming a disturbance with the upper washing water, so that the unseparated heavy oil in the upper washing water falls again due to the disturbance, thereby achieving deep treatment of the washing water.

[0034] like Figure 3 and Figure 5As shown, the oil collecting tank 13 of the present invention is located within the secondary separation cylinder 17. Multiple support plates 12 are symmetrically connected to the outer side of the upper end of the oil collecting tank 13, and one end of the support plates 12 is fixed to the shell 1. The lower end of the oil collecting tank 13 is connected to the light oil discharge port 8. The clean water discharge port 7 and the light oil discharge port 8 are located at the lower portion of the shell 1, with the clean water discharge port 7 located above the light oil discharge port 8. In this way, the rising light oil phase and the water phase naturally separate due to their density differences. As the light oil phase increases, it overflows into the oil collecting tank 13, achieving separation of the light oil phase and the water phase. The light oil is discharged through the light oil discharge port 8, while the clean wash water, which has been separated into components such as heavy oil and light oil, is discharged from the clean water discharge port 7. The rising gas phase is discharged from the exhaust port 2.

[0035] To prevent the eddy current field from impacting the settled heavy oil, the present invention provides a heavy oil collector 15 inside the conical bucket 3. A cross plate 18 is fixed inside the conical bucket 3. The cross plate 18 passes through the heavy oil collector 15 and is fixed to the conical bucket 3 at one end, thereby fixing the heavy oil collector 15 to the conical bucket 3. In addition, the cross section of the heavy oil collector 15 is a trapezoid that is narrow at the top and wide at the bottom. In this way, the heavy oil is gathered toward the center of the heavy oil collector 15 along with the eddy current, and flows from the heavy oil collector 15 to the bottom of the conical bucket 3 under the action of gravity, and is discharged from the heavy oil discharge port 6 provided below the conical bucket 3.

[0036] like Figure 4 As shown, in the present invention, the upper end of the first-stage separation cylinder 16 contracts inward, and the upper end of the second-stage separation cylinder 17 expands outward. The first-stage separation cylinder 16 with the upper end contracted inward can reduce the rising speed of the light oil phase, so that the entrained trace heavy oil can be settled again, while the second-stage separation cylinder 17 with the upper end expanded outward can accelerate the rising speed of the bubbles in the light oil phase, thereby realizing the rapid separation of the light oil phase and the gas phase.

[0037] like Figure 1 As shown, since the heavy oil phase is relatively viscous and easily clogs the heavy oil discharge port 6, the present invention further provides a flushing port 5 on the conical bucket 3 to periodically introduce flushing water to flush the conical bucket 3.

[0038] The present invention provides a primary separation cylinder 16 and a vortex forming assembly 9, utilizing vortex flow to separate the light oil phase from the heavy oil phase at the primary separation cylinder 16. The secondary separation cylinder 17 and annular distributor 11 are provided to cause unseparated heavy oil in the upper wash water to descend again due to disturbance, achieving deep treatment of the wash water. The oil collecting tank 13 is provided to allow the rising light oil phase and the water phase to naturally separate due to density differences. As the light oil phase increases, it overflows into the oil collecting tank 13, achieving separation of the light oil phase and the water phase. The present invention achieves efficient separation of four phases: oil phase and water phase, liquid phase and gas phase, light oil phase and heavy oil phase, and light oil phase and water phase, through secondary flotation, thereby improving the flotation effect.

[0039] The embodiments described above are only preferred embodiments of the present invention and are only used to explain the present invention, not to limit the scope of implementation of the present invention. For those skilled in the art, it is of course possible to easily make other implementation methods by replacing or changing the technical content disclosed in this specification. Therefore, all changes and improvements made on the principles of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water, comprising a shell (1), characterized in that: It also includes an exhaust port (2), a conical bucket (3), a first-level dissolved air water inlet (4), a heavy oil discharge port (6), a clean water discharge port (7), a light oil discharge port (8), a vortex forming component (9), a second-level dissolved air water inlet (10), an annular distributor (11), an oil collecting tank (13), a first-level separation cylinder (16) and a second-level separation cylinder (17); The exhaust port (2) is provided at the upper end of the shell (1), and the conical bucket (3) is provided at the lower end of the shell (1); the first-stage dissolved air water inlet (4) is provided at the junction of the shell (1) and the conical bucket (3), and the first-stage dissolved air water inlet (4) is communicated with a vortex forming component (9) located inside the first-stage separation cylinder (16), and the vortex forming component (9) includes a plurality of arc-shaped water outlet pipes (9-2) and ribs (9-3), one end of each water outlet pipe (9-2) is a trumpet-shaped nozzle (9-1), and each section of the water outlet pipe (9-2) is connected end to end through the ribs (9-3) to form a ring; The lower parts of the primary separation cylinder (16) and the secondary separation cylinder (17) are connected, the lower part of the primary separation cylinder (16) is fixed to the conical bucket (3), and there is a gap between the primary separation cylinder (16), the secondary separation cylinder (17) and the shell (1); The secondary dissolved air water inlet (10) is arranged in the middle of the shell (1) and is connected to the annular distributor (11) surrounding the outside of the secondary separation cylinder (17); The oil collecting tank (13) is located in the secondary separation cylinder (17) and its upper end is fixed to the shell (1), and the lower end of the oil collecting tank (13) is connected to the light oil discharge port (8); The clean water discharge port (7) and the light oil discharge port (8) are arranged at the lower part of the shell (1), and the clean water discharge port (7) is located above the light oil discharge port (8); The heavy oil discharge port (6) is arranged below the conical bucket (3).

2. The two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water according to claim 1 is characterized in that: A heavy oil collector (15) is provided inside the conical bucket (3), and a cross plate (18) is fixed inside the conical bucket (3). The cross plate (18) passes through the heavy oil collector (15) and one end of the cross plate is fixed to the conical bucket (3).

3. The two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water according to claim 2, characterized in that: The cross section of the heavy oil collector (15) is a trapezoid that is narrow in length and wide at the bottom.

4. The two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water according to claim 1, characterized in that: The upper end of the first-stage separation cylinder (16) contracts inward, and the upper end of the second-stage separation cylinder (17) expands outward.

5. The two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water according to claim 1, characterized in that: A plurality of support plates (12) are symmetrically connected to the outer side of the upper end of the oil collecting tank (13), and one end of the support plate (12) is fixed to the housing (1).

6. The two-stage dissolved gas four-phase separation vortex flotation tower for biomass pyrolysis gas washing water according to claim 1, characterized in that: The conical bucket (3) is also provided with a flushing port (5).

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