MVR reaction pretreatment equipment and use method thereof

Abstract

Disclosed are an MVR reaction pretreatment device and a method for using the same. The present invention belongs to the field of environmental pollution control. To address problems such as impurities and corrosion, limited treatment efficiency, and mother liquor drying and foaming, the present invention provides an MVR reaction pretreatment device. The pretreatment device comprises a shell, a jet structure unit disposed within the shell, an ultraviolet lamp column unit, and a reaction mixing unit spirally propelled around the ultraviolet lamp column unit and connected to the jet structure unit. The device provided by the present invention saves space, integrates mixing and reaction, improves the mixing effect through a secondary mixing mechanism, and greatly solves common MVR problems such as mother liquor drying and foaming, evaporator scaling, and high evaporation mother liquor output.

Description

Technical Field

[0001] The present invention relates to the field of environmental pollution control, and in particular to an MVR pretreatment device based on advanced oxidation and a method for using the same. Background Art

[0002] Mechanical Vapor Recompression (MVR) reactors in water treatment engineering are a highly efficient and energy-efficient evaporation and concentration technology widely used in sewage treatment and wastewater resource recovery. As an evaporation and concentration technology, MVR reactors offer advantages such as low energy consumption, compact equipment structure, and stable operation, making them a research hotspot and application area in sewage treatment and wastewater resource recovery.

[0003] Common MVR pretreatment processes generally include: screen filtration, precipitation, neutralization adjustment, activated carbon adsorption, etc., but even after pretreatment, the following problems often exist: 1. Impurity and corrosion problems: The wastewater may contain a large amount of impurities, salts and organic matter, etc. These impurities may cause blockage, fouling and corrosion to the MVR reactor equipment, which may cause equipment performance degradation and require regular cleaning and maintenance; 2. Limited treatment efficiency: When the MVR reactor treats high-concentration wastewater or high-salinity wastewater, the treatment efficiency may be limited. In some cases, multi-stage evaporation concentration or other additional processes may be required to achieve higher concentration efficiency; 3. The existing MVR treatment has problems with mother liquor drying and foaming, evaporator scaling, and high evaporation mother liquor production. Summary of the Invention

[0004] To solve the above-mentioned problems, the present invention provides an MVR reaction pretreatment equipment, which includes a shell, a jet structure unit arranged inside the shell, an ultraviolet lamp column unit, and a reaction mixing unit spirally propelled around the ultraviolet lamp column unit and connected to the jet structure unit; the water inlet end of the shell is provided with a water inlet and an air inlet / liquid pipe, and the water outlet end is provided with a water outlet pipe; the jet structure unit is provided with openings at corresponding positions of the water inlet, air inlet / liquid pipe and water outlet pipe; the reaction mixing unit includes a mixing channel and a spiral cutting device that spirally extend from the water inlet end to the water outlet end around the ultraviolet lamp column unit and are parallel to each other, the spiral cutting device includes a spiral skeleton with a direction consistent with the mixing channel and more than one cutting modules uniformly arranged on the spiral skeleton with a deflection angle of 30-60°, the spiral angle of the mixing channel and the spiral skeleton around the ultraviolet lamp column unit is 15~30°; the surface of the mixing channel and the spiral cutting device is coated with a coating with ozone catalytic function.

[0005] Furthermore, the direction of the water outlet pipe is consistent with the water flow direction at the water outlet end of the reaction mixing unit.

[0006] Furthermore, the mixing channel includes a water passing surface, an outer side surface of the mixing channel and an inner side surface of the mixing channel, and the water passing surface is a concave surface.

[0007] Furthermore, the inner wall of the shell and the outer surface of the ultraviolet lamp column unit are provided with threads or guide rails, and the outer side surface and the inner side surface of the mixing channel are fixed between the inner wall of the shell and the outer surface of the ultraviolet lamp column unit through threads or guide rails respectively.

[0008] Furthermore, the outer wall of the ultraviolet lamp column unit is composed of outer wall concave plate sections and outer wall flat plate sections alternating in sequence. The outer wall flat plate section is used to fix the mixing channel. The outer wall concave plate section, the inner surface of the shell located opposite to the outer wall concave plate section, and two opposite water flow surfaces form a water flow channel that is nearly circular.

[0009] Furthermore, the cutting module includes a spherical structure arranged on a spiral skeleton and spindle-like structures symmetrically arranged on both sides of the spherical structure, and the spindle-like structures extend and are fixed to the mixing channel.

[0010] Furthermore, the jet structure unit is a Venturi tube structure, and the air / liquid inlet pipe is connected to the thinnest part of the jet structure.

[0011] Furthermore, all water-passing surfaces of the mixing channel, the spiral cutting device and the spiral skeleton are treated with acid and alkali resistance and rust prevention.

[0012] The present invention also provides a method for using the MVR reaction pretreatment equipment, wherein the method comprises the following steps:

[0013] (1) connecting one or more of the MVR reaction pretreatment equipment in parallel or in series and then placing them in front of the MVR reactor and connecting them thereto;

[0014] (2) connecting the ozone generator to the gas / liquid inlet pipe of the MVR reaction pretreatment;

[0015] (3) The reflux concentrate and hydrogen peroxide solution are introduced into the water inlet, and the inlet liquid is mixed with the ozone from the ozone generator through the jet structure and then injected into the reaction mixing unit, where they are secondary mixed and simultaneously fully contacted with the ultraviolet light / ozone layer to cause an oxidation reaction;

[0016] (4) The influent is discharged from the outlet pipe, and after the pretreatment is completed, it enters the MVR reactor. The liquid part after the MVR reaction flows back to the original inlet and continues to be pretreated together with the raw water.

[0017] Furthermore, the ozone concentration provided by the ozone generator is 20-50 mg / NL, the hydrogen peroxide concentration can be 5-20 mg / L, and the flow ratio is 50-85%.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. In the existing technology, pretreatment processes mostly include various separation, filtration, and precipitation processes, and the equipment occupies a large area, and some also require civil engineering support. The equipment provided by the present invention saves space, combines mixing and reaction in one, and also saves space for catalysts. The coating process also greatly reduces the risk of reactor clogging.

[0020] 2. The technical solution provided by the present invention has a secondary mixing mechanism, the first time passing through the ejector and the second time passing through the reaction mixing unit, which makes the mixing more complete. In addition, the advanced oxidation reaction occurs simultaneously during the second mixing stage. Due to the unique fluid dynamics structure design, the mixing reaction is efficient.

[0021] 3. With this pre-treatment process, the entire MVR can basically achieve full quantitative processing;

[0022] 4. Additional hydrogen peroxide is added. According to the advanced oxidation reaction mechanism, the addition of hydrogen peroxide will greatly promote the reaction, making it efficient and fast;

[0023] 5. This pretreatment greatly solves the common problems of MVR, such as mother liquor drying and foaming, evaporator scaling, and high evaporation mother liquor production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the overall schematic diagram of the MVR pretreatment equipment.

[0025] Figure 2 It is a schematic diagram of the axial section of the MVR pretreatment equipment (perspective).

[0026] Figure 3 It is a schematic diagram of the UV lamp column unit of the equipment (section along the axis).

[0027] Figure 4 It is a schematic diagram of the equipment reaction mixing unit 2.

[0028] Figure 5 Schematic diagram of the mixing channel 21 of the device.

[0029] Figure 6 It is a schematic diagram of the spiral cutting device 22 of the equipment.

[0030] Figure 7 This is the process flow chart of MVR pretreatment. DETAILED DESCRIPTION

[0031] The present invention will be further explained and illustrated below in conjunction with the accompanying drawings.

[0032] Example 1

[0033] Please refer to Figure 1-7 , an MVR reaction pretreatment equipment, including a shell 1, a jet structure unit 15 arranged inside the shell 1, an ultraviolet lamp column unit 3 and a reaction mixing unit 2 spirally propelled around the ultraviolet lamp column unit 3; the shell 1 is provided with a water inlet 11 and an air (liquid) inlet pipe 12 at the head end, and a water outlet pipe 13 at the tail end. The water outlet pipe 13 is connected to the end of the reaction mixing unit 2, and the direction of the water outlet pipe 13 is consistent with the water outlet direction of the end, so as to minimize the water outlet resistance and ensure smooth outflow of water.

[0034] The cross section of the shell 1 is a circular or polygonal columnar structure, and the inner wall 16 of the shell is a cylindrical wall. The inner wall is provided with threads or guide rails for fixing the reaction mixing unit 2.

[0035] The jet structure unit 15 is arranged at the water inlet end of the shell 1, and the water inlet 11 corresponds to the water inlet of the jet structure unit 15. The jet structure 15 unit is a Venturi tube structure, and the air (liquid) inlet pipe 12 is connected to the thinnest part of the jet structure unit 15; water enters the jet structure unit 15 through the water inlet 11, and after mixing with the gas (liquid) from the air (liquid) inlet pipe 12 at the thinnest part, it is quickly sprayed into the reaction mixing unit 2.

[0036] The ultraviolet lamp column unit 3 extends into the reaction mixing unit 2 to provide ultraviolet light irradiation for the fluid in the reaction mixing unit 2. Preferably, the ultraviolet lamp column unit 3 is a hollow cylindrical structure provided with an ultraviolet lamp column cock 33, and an ultraviolet lamp is installed therein.

[0037] The reaction mixing unit 2 includes a mixing channel 21 and a spiral cutting device 22 extending spirally from the water inlet end to the water outlet end around the ultraviolet lamp column unit 3. Figure 5 As can be seen, the mixing channel 21 includes a water-passing surface 220, an outer side surface 211 of the mixing channel, and an inner side surface 212 of the mixing channel. The water-passing surface 220 is a concave surface similar to a slide, wherein the outer side surface 211 of the mixing channel is fixed to the inner wall of the housing 1 by threads or guide rails; the inner side surface 212 of the mixing channel is fixed to the outer surface of the ultraviolet lamp column unit 3 by threads or guide rails, thereby fixing the mixing channel 21 between the housing 1 and the ultraviolet lamp column unit 3. The two opposing water-passing surfaces 220, the outer surface of the ultraviolet lamp column unit 3, and the inner surface of the housing 1 form a nearly circular water flow channel, through which water flows and mixes. The side of the ultraviolet lamp column unit 3 is a plano-concave mirror surface. The ultraviolet light is emitted from the ultraviolet lamp column unit 3, passes through the plano-concave mirror surface, and then diverges in the water flow channel, achieving a more effective ultraviolet catalysis.

[0038] like Figure 6 As shown, the spiral cutting device 22 is composed of a plurality of cutting units, wherein the cutting unit includes a spiral skeleton 222 arranged at the center line of the water flow channel or close to the center line, and one or more cutting modules 221 evenly arranged on the spiral skeleton 222; the cutting module 221 includes a spherical structure arranged on the spiral skeleton 222 and spindle-shaped structures arranged on both sides of the spherical structure, the central axes of the spindle-shaped structures on both sides pass through the center of the sphere, and extend toward the mixing channels 21 located on both sides of the cutting unit and are fixed to the mixing channels 21, and the spiral skeleton 222 and the mixing channel 21 form a DNA-like double helix structure.

[0039] like Figure 6 As shown, multiple cutting modules 221 are staggered and arranged in a spiral skeleton 222 at a deflection angle of 30-60° (α). For example, the second cutting module A2 (arranged at the back) is deflected 30-60° in the clockwise direction relative to the first cutting module A1 (arranged at the front), and the third is deflected 30-60° in the clockwise direction relative to the second cutting module, and so on. With such an arrangement, when water spirals forward in the water flow channel, it will collide head-on with at least one of the cutting modules. Water in different directions will collide with different cutting modules. Continuous collisions will enhance the mixing of water in the water flow channel, forming fluids with different flow directions. Therefore, no matter from which direction it enters the channel, it can eventually achieve full contact with the ultraviolet light. In addition, as Figure 3 As shown, the tilt angle (β) between the mixing channel 21 and the UV lamp column plug 33 is 15-30 degrees.

[0040] Since the spiral skeleton 222 and the mixing channel 21 are in parallel, the spiral angle of the double helix structure formed by the two around the ultraviolet lamp column unit 3 is also 15-30 degrees.

[0041] Preferably, the shell 1 is made of a metal material with a certain strength or an opaque non-metallic material, such as 316L stainless steel; the mixing channel 21 and the cutting unit are made of a metal material with a certain strength or an opaque or reflective non-metallic material; the mixing channel 21, the surface of the spiral cutting device and the spiral skeleton 222 are coated with a coating with ozone catalytic function, and if necessary, all water-passing surfaces can be treated with acid and alkali resistance and rust prevention.

[0042] Preferably, the outer wall 31 of the ultraviolet lamp column unit 3 is composed of an outer wall concave section 311 and an outer wall flat section 312. The outer wall concave section 311 corresponds to the plano-concave mirror section of the water flow channel, and the ultraviolet light enters the water flow channel from the plano-concave mirror section and fully contacts the water flow. The outer wall flat section 312 corresponds to the inner side surface 212 of the mixing channel. The outer wall flat section 312 has threads or guide rails for mechanical connection with the reaction mixing unit 2; the outer wall concave section 311 is matched with the water channel formed with the adjacent mixing channel 21, and the ultraviolet lamp column cavity 32 is a cylindrical cavity structure for placing the ultraviolet lamp tube.

[0043] The material of the ultraviolet lamp column unit 3 is a light-transmitting organic material with certain corrosion resistance, which can be glass; the outer wall concave plate section 311 is a plano-concave lens in cross-section along the axis.

[0044] Example 2

[0045] The present invention also provides a method for using an MVR pretreatment device based on advanced oxidation, please refer to Figure 7 :

[0046] (1) Properly connect one or a group (consisting of several pretreatment reactors connected in parallel or in series) of the pretreatment reactor to the MVR reactor;

[0047] (2) The ozone generator is properly connected to the air (liquid) inlet pipe 12, and the ozone concentration can be 50 mg / NL;

[0048] (3) The reflux concentrate and hydrogen peroxide solution are injected into the water inlet 11 before the pretreatment reactor. The concentration of hydrogen peroxide can be 5-20 mg / L.

[0049] (4) The incoming water is mixed with the ozone from the ozone generator through the jet structure 15;

[0050] (5) The influent water is secondary mixed through the reaction mixing unit 2 and undergoes oxidation reaction in the UV / ozone advanced oxidation system;

[0051] (6) The influent is discharged from the outlet pipe 13, and the pretreatment is completed before entering the MVR reactor;

[0052] (7) The concentrated liquid from the MVR reactor flows back into the raw water at a certain reflux ratio, which can be 85%.

Claims

1. An MVR reaction pretreatment equipment, characterized in that, The pretreatment equipment includes a shell, a jet structure unit arranged inside the shell, an ultraviolet lamp column unit, and a reaction mixing unit spirally propelled around the ultraviolet lamp column unit and connected to the jet structure unit; the water inlet end of the shell is provided with a water inlet and an air / liquid pipe, the water outlet end is provided with a water outlet pipe, and the water outlet pipe is connected to the end of the reaction mixing unit; the jet structure unit is provided with openings at corresponding positions of the water inlet and the air / liquid pipe; the reaction mixing unit includes a mixing channel and a spiral extending from the water inlet end to the water outlet end around the ultraviolet lamp column unit and parallel to each other A spiral cutting device, the spiral cutting device includes a spiral skeleton with a direction consistent with the mixing channel and one or more cutting modules evenly arranged on the spiral skeleton with a deflection angle of 30~60°. The angle of the spiral of the mixing channel and the spiral skeleton around the ultraviolet lamp column unit is 15~30°; the surface of the mixing channel and the spiral cutting device is coated with a coating with ozone catalytic function. The cutting module includes a spherical structure provided on the spiral skeleton and spindle-like structures symmetrically provided on both sides of the spherical structure. The spindle-like structure extends and is fixed to the mixing channel.

2. The MVR reaction pretreatment equipment according to claim 1, characterized in that: The direction of the water outlet pipe is consistent with the water flow direction of the water outlet end of the reaction mixing unit.

3. The MVR reaction pretreatment equipment according to claim 1, characterized in that: The mixing channel comprises a water passing surface, an outer side surface of the mixing channel and an inner side surface of the mixing channel, and the water passing surface is a concave surface.

4. The MVR reaction pretreatment equipment according to claim 3, characterized in that: The inner wall of the shell and the outer surface of the ultraviolet lamp column unit are provided with threads or guide rails, and the outer side surface and the inner side surface of the mixing channel are fixed between the inner wall of the shell and the outer surface of the ultraviolet lamp column unit through threads or guide rails respectively.

5. The MVR reaction pretreatment equipment according to claim 3, characterized in that: The outer wall of the ultraviolet lamp column unit is composed of outer wall concave plate sections and outer wall flat plate sections alternating in sequence. The outer wall flat plate section is used to fix the mixing channel. The outer wall concave plate section, the inner surface of the shell located opposite to the outer wall concave plate section, and two opposite water flow surfaces form a water flow channel that is nearly circular.

6. The MVR reaction pretreatment equipment according to claim 1, characterized in that: The jet structure unit is a Venturi tube structure, and the air / liquid inlet pipe is connected to the thinnest part of the jet structure.

7. The MVR reaction pretreatment equipment according to claim 1, characterized in that: The mixing channel, the spiral cutting device and all water-passing surfaces of the spiral skeleton are treated with acid and alkali resistance and rust prevention.

8. The method for using the MVR reaction pretreatment equipment according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: (1) connecting one or more of the MVR reaction pretreatment equipment in parallel or in series and then placing them in front of the MVR reactor and connecting them thereto; (2) connecting the ozone generator to the gas / liquid inlet pipe of the MVR reaction pretreatment; (3) The reflux concentrate and hydrogen peroxide solution are introduced into the water inlet, and the inlet liquid is mixed with the ozone from the ozone generator through the jet structure and then injected into the reaction mixing unit, where they are secondary mixed and simultaneously fully contacted with the ultraviolet light / ozone layer to cause an oxidation reaction; (4) The influent is discharged from the outlet pipe, and after the pretreatment is completed, it enters the MVR reactor. The liquid part after the MVR reaction flows back to the original inlet and continues to be pretreated together with the raw water.

9. The method for using the MVR reaction pretreatment equipment according to claim 8, characterized in that: The ozone concentration provided by the ozone generator is 20~50mg / NL, the hydrogen peroxide concentration is 5~20mg / L, and the flow ratio is 50~85%.

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