Waste treatment system and method

Abstract

The present invention provides a waste treatment system and method. The waste includes a liquid-solid mixture and gas, and the liquid-solid mixture includes water, volatile organic compounds, and solid powder. The waste treatment system includes: a primary separation mechanism to remove some of the gas and at least some of the solid powder from the waste to obtain a primary treatment product; a secondary separation mechanism to remove at least some of the volatile organic compounds from the primary treatment product to obtain a secondary treatment product; and a tertiary separation mechanism to perform gas-liquid separation on the secondary treatment product. This waste treatment system and method can effectively reduce environmental pollution caused by volatile organic compounds in the waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial wastewater treatment, and in particular relates to a waste treatment system and method. Background Art

[0002] During the polypropylene production process, the wastewater discharged from the scrubber in the steam drying unit contains solid powder, volatile organic compounds, and non-volatile organic compounds. As the wastewater exits the scrubber, gases within the scrubber are also ejected along with the wastewater, causing dramatic fluctuations in the scrubber discharge flow rate and pushing the wastewater pressure close to atmospheric pressure.

[0003] The conventional method for treating scrubber effluent is to pipe it into an open collection tank. After settling for a period of time, the lightly dense solid powder within floats to the surface and is manually salvaged and bagged periodically. While the open collection tank facilitates the salvaging of the solid powder, it also allows volatile organic compounds (VOCs) to evaporate directly into the atmosphere, causing VOC levels to exceed standards. Summary of the Invention

[0004] The present invention aims to provide a waste treatment system and method to reduce VOC pollution.

[0005] To achieve the above object, the present invention provides a waste treatment system, wherein the waste includes a liquid-solid mixture and a gas, and the liquid-solid mixture includes water, volatile organic compounds, and solid powder. The waste treatment system includes:

[0006] A primary separation mechanism for removing part of the gas and at least part of the solid powder in the waste to obtain a primary treatment product;

[0007] a secondary separation mechanism for removing at least part of the volatile organic compounds in the primary treatment product and obtaining a secondary treatment product; the secondary separation mechanism comprises a first shell and an acceleration mechanism disposed within the first shell, the first shell having an upper cavity and a lower cavity, the upper cavity being in communication with the primary separation mechanism; the acceleration mechanism having an acceleration channel, the acceleration channel being in communication with the upper cavity and the lower cavity, the acceleration channel being configured to accelerate the gas in the primary treatment product, thereby causing the liquid in the primary treatment product to disperse into droplets and spray into the lower cavity; and,

[0008] The tertiary separation mechanism is connected to the lower cavity and is used for performing gas-liquid separation on the secondary treatment product.

[0009] Optionally, the first shell has a first inner cavity; the acceleration mechanism includes a partition and at least one acceleration core tube; the partition is arranged in the first inner cavity and divides the first inner cavity into the upper cavity and the lower cavity; the acceleration core tube is arranged on the partition and includes a coaxially arranged main tube and an outlet tube, the upper end of the main tube is located in the upper cavity, and the outlet tube is located in the lower cavity; the acceleration core tube has a third inner cavity that passes through the main tube and the outlet tube, and the inner diameter of the third inner cavity at the outlet tube gradually increases in the direction away from the main tube, and the third inner cavity of each acceleration core tube constitutes an acceleration channel; the upper end opening of the acceleration core tube constitutes a first inlet for gas to enter the third inner cavity, and a second inlet for liquid to enter the third inner cavity is provided on the side wall of the main tube, the second inlet is located in the upper cavity, and the lower end opening of the acceleration core tube constitutes a first outlet for liquid droplets to be ejected.

[0010] Optionally, the cross-section of the third inner cavity is circular, the minimum diameter of the third inner cavity is 6mm-30mm, and the ratio of the maximum diameter to the minimum diameter of the third inner cavity is 1.1-2; the area of the second inlet is 0.00001m2-0.0001m2; the acute angle formed by the cavity wall of the third inner cavity at the ejection pipe and the axis of the acceleration core tube is 2.5°-10°.

[0011] Optionally, the primary separation mechanism includes a cyclone distributor and a negative pressure filter, the cyclone distributor includes a second shell and a plurality of suppression baffles, the second shell has a second inner cavity extending vertically, and the cross-section of the second inner cavity is circular; a third inlet is provided on the side wall of the second shell, and the axis of the third inlet is parallel to the tangent of the second shell at the third inlet; a plurality of the suppression baffles are arranged in the second inner cavity and below the third inlet, and the plurality of the suppression baffles are arranged at intervals along the circumference of the second inner cavity, and each of the suppression baffles extends radially along the second inner cavity; the negative pressure filter is arranged at the lower end of the cyclone distributor, and the negative pressure filter has a second outlet for the primary treatment product to flow out, and the second outlet is connected to the upper cavity of the secondary separation mechanism through a pipeline.

[0012] Optionally, the plurality of suppression baffles are aligned in the axial direction of the second inner cavity, and the plurality of suppression baffles are evenly arranged in the circumferential direction of the second inner cavity.

[0013] Optionally, the ratio of the equivalent diameter of the third inlet to the diameter of the second inner cavity is 1:5-1:2; the ratio of the axial length of the second inner cavity to the diameter of the second inner cavity is 1:2-1:9; the ratio of the radial length of the suppression baffle in the second inner cavity to the diameter of the second inner cavity is 0.1:1-0.3:1.

[0014] Optionally, the primary separation mechanism further comprises a cover body, the cover body being arranged to cover the outside of the cyclone distributor and the negative pressure filter, and the cover body being provided with a third outlet and a fourth outlet, the third outlet being connected to a vacuum pump through a pipeline, and the fourth outlet being provided for a pipeline connecting the second outlet of the negative pressure filter and the upper cavity of the secondary separation mechanism;

[0015] The three-stage separation mechanism has a fifth outlet for gas circulation, and the fifth outlet is connected to the vacuum pump.

[0016] To achieve the above object, the present invention further provides a waste treatment method, wherein the waste includes a liquid-solid mixture and a gas, and the liquid-solid mixture includes water, volatile organic compounds, and solid powder. The treatment method comprises the following steps:

[0017] performing primary separation on the waste to remove a portion of gas and at least a portion of solid powder, and obtain a primary treatment product;

[0018] performing secondary separation on the primary treatment product to remove at least a portion of volatile organic compounds and obtain a secondary treatment product; and

[0019] The secondary treatment product is subjected to gas-liquid separation; wherein,

[0020] The secondary separation includes: accelerating the gas in the primary treatment product, using the accelerated gas to disperse the liquid in the primary treatment product into droplets, and moving the droplets downward a predetermined distance.

[0021] Optionally, a secondary separation mechanism is used to perform secondary separation on the primary treatment product, the secondary separation mechanism comprising a first shell and an acceleration mechanism, the first shell having a first inner cavity, the first inner cavity being divided by the acceleration mechanism into an upper cavity and a lower cavity, the upper cavity being used to receive the primary treatment product; the acceleration mechanism having an acceleration channel, the acceleration channel communicating with the upper cavity and the lower cavity, and the acceleration channel being configured to accelerate gas in the primary treatment product, thereby causing liquid in the primary treatment product to disperse into droplets and spray into the lower cavity;

[0022] The apparent flow velocity of the gas in the primary treatment product in the first inner cavity is 0.1m / s-1m / s, and the apparent flow velocity of the gas in the primary treatment product in the acceleration channel is 30m / s-80m / s; the apparent flow velocity of the liquid in the primary treatment product in the first inner cavity is less than or equal to 0.1m / s.

[0023] Optionally, when the temperature of the liquid-solid mixture is 5°C-20°C, the predetermined distance is 0.9m-1.5m;

[0024] When the temperature of the liquid-solid mixture is 20°C-35°C, the predetermined distance is 0.4m-0.9m;

[0025] When the temperature of the liquid-solid mixture is 35°C-50°C, the predetermined distance is 0.2m-0.4m;

[0026] When the temperature of the liquid-solid mixture is greater than 50° C., the predetermined distance is 0.2 m.

[0027] Optionally, the primary separation includes: centrifuging the waste to separate part of the gas in the waste and obtain a primary treatment product in a cyclonic state;

[0028] Controlling the primary treatment product to stop the swirling flow and allowing the primary treatment product to flow vertically downward into the negative pressure filter; and,

[0029] The primary treatment product is subjected to negative pressure filtration to separate at least part of the solid powder in the primary treatment product and obtain the primary treatment product.

[0030] Optionally, the primary treatment product is subjected to negative pressure filtration using a negative pressure filter, wherein the negative pressure filter comprises a filter cloth; the liquid-solid mixture comprises an oil phase substance;

[0031] When the content of the oil phase substance in the liquid-solid mixture is 0-1 mg / L, the pore size of the filter pores on the filter cloth is 0.2-0.5 times the Sauter mean diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is 0.002 m / s-0.004 m / s;

[0032] When the content of the oil phase substance in the liquid-solid mixture is 1-1000 mg / L, the pore size of the filter pores on the filter cloth is 0.5-1 times the Sauter mean diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is 0.001 m / s-0.002 m / s;

[0033] When the content of the oil phase substance in the liquid-solid mixture is greater than 1000 mg / L, the pore size of the filter holes on the filter cloth is 1-1.5 times the Sauter average diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is less than or equal to 0.001 m / s.

[0034] Optionally, the waste is centrifuged using a cyclone distributor;

[0035] The flow velocity of the waste when entering the cyclone distributor is 0.5m / s-50m / s. During centrifugal separation, the superficial velocity of the liquid in the waste is 0.04m / s-0.5m / s, and the centrifugal acceleration is 5 times to 500 times the acceleration of gravity.

[0036] Compared with the prior art, the waste treatment system and method of the present invention has the following advantages:

[0037] The aforementioned waste treatment system can be used to treat waste discharged through a washing tower during the polypropylene production process, wherein the waste includes a liquid-solid mixture and gas, and the liquid-solid mixture includes water, volatile organic matter and solid powder; the waste treatment system includes a primary separation mechanism, a secondary separation mechanism and a tertiary separation mechanism, wherein the primary separation mechanism is used to remove part of the gas and at least part of the solid powder in the waste and obtain a primary treatment product; the secondary separation mechanism is used to remove at least part of the volatile organic matter in the primary treatment product and obtain a secondary treatment product, and the tertiary separation mechanism is used to perform gas-liquid separation on the secondary treatment product; wherein the secondary separation mechanism includes a first shell and an acceleration mechanism arranged in the first shell, the first shell having an upper cavity and a lower cavity, the upper cavity being connected to the primary separation mechanism; the acceleration mechanism has an acceleration channel, the acceleration channel connecting the upper cavity and the lower cavity, and the acceleration channel is configured to accelerate the gas in the primary gas-liquid mixture so that the liquid in the primary treatment product is dispersed into droplets and sprayed into the lower cavity. After the liquid in the primary treatment product is dispersed into droplets by utilizing the acceleration channel, the gas-liquid contact area is increased, so that the volatile organic compounds in the liquid can be quickly separated by mass transfer and volatilized, thereby improving the removal efficiency of the volatile organic compounds, and greatly reducing the volatile organic compounds in the secondary treatment product entering the tertiary separation mechanism. The separated volatile organic compounds remain in the lower cavity and will not leak into the environment, thereby effectively reducing VOC pollution.

[0038] Furthermore, the primary separation mechanism includes a cyclone distributor and a negative pressure filter. The waste is centrifuged by the cyclone distributor to obtain a primary treatment product, and then the primary treatment product is filtered by the negative pressure filter, which can intercept and discharge solid powder. There is no need to manually collect solid powder, which reduces labor intensity and also reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are provided for a better understanding of the present invention and are not intended to limit the present invention.

[0040] Figure 1 is a schematic structural diagram of a waste treatment system provided according to one embodiment of the present invention;

[0041] Figure 2 1 is a schematic structural diagram of a cyclone distributor of a waste treatment system according to one embodiment of the present invention;

[0042] Figure 3 is a top view of a swirl distributor of a waste treatment system provided by one embodiment of the present invention;

[0043] Figure 4 1 is a schematic structural diagram of a cyclone distributor of a waste treatment system according to one embodiment of the present invention;

[0044] Figure 5 It is a structural schematic diagram of an accelerating core tube of a secondary separation mechanism of a waste treatment system provided according to one embodiment of the present invention.

[0045] [The following are the descriptions of the reference numerals]:

[0046] 1000-first-stage separation mechanism, 1100-cyclone distributor, 1110-second shell, 1111-second inner cavity, 1112-third inlet, 1120-suppression baffle, 1200-negative pressure filter, 1300-cover body, 1310-third outlet, 1320-fourth outlet, 1330-sixth outlet, 2000-second-stage separation mechanism, 2100-first shell, 2110-upper cavity, 2120-lower cavity, 2200-acceleration mechanism, 2210-partition, 2220-acceleration core tube, 2221-main tube, 2222-discharge tube, 2223-first inlet, 2224-second inlet, 2225-first outlet, 3000-third-stage separation mechanism, 3001-fifth outlet, 4000-vacuum pump. DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components during actual implementation. During actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0048] In addition, each embodiment described below has one or more technical features. However, this does not mean that users of the present invention must implement all technical features in any embodiment at the same time, or that they can only implement some or all technical features in different embodiments separately. In other words, as long as implementation is possible, those skilled in the art can, based on the disclosure of the present invention and depending on design specifications or implementation requirements, selectively implement some or all technical features in any embodiment, or selectively implement a combination of some or all technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0049] As used in this specification, the singular forms "a", "an", and "the" include plural objects, and the plural form "a plurality" includes more than two objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise, and the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and it can be internal communication between two elements or an interactive relationship between two elements. Relational terms such as "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly indicate the number of technical features indicated. It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "axial," "radial," "circumferential," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate description and simplify the description of the present invention. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0050] The object of the present invention is to provide a waste treatment system, which can be used to treat waste discharged through a washing tower in a polypropylene production process and reduce the pollution of volatile organic compounds in the waste to the environment.

[0051] To make the objects, advantages, and features of the present invention more apparent, the present invention is further described below in detail with reference to the accompanying drawings. It should be noted that the drawings are greatly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar components.

[0052] Those skilled in the art will appreciate that when the waste is the discharge from a scrubbing tower used to produce the polypropylene, the waste comprises a liquid-solid mixture and gas discharged simultaneously with the liquid-solid mixture, i.e., the waste is a gas-liquid-solid mixture. The liquid-solid mixture comprises water, solid powder, and organic matter, specifically volatile organic matter and non-volatile organic matter. At least a portion of the organic matter is present as an oil phase in the liquid-solid mixture.

[0053] Figure 1 FIG. 1 is a schematic diagram showing the structure of a waste treatment system provided by an embodiment of the present invention. Figure 1 As shown, the waste treatment system includes a primary separation mechanism 1000, a secondary separation mechanism 2000, and a tertiary separation mechanism 3000, which are connected in sequence. The primary separation mechanism 1000 is used to separate part of the gas and at least part of the solid powder in the waste, and obtain a primary treatment product. The secondary separation mechanism 2000 is used to remove at least part of the volatile organic compounds in the primary treatment product, and obtain a secondary treatment product. The tertiary separation mechanism 3000 is used to perform gas-liquid separation on the secondary treatment product. The secondary separation mechanism includes a first shell 2100 and an acceleration mechanism 2200 disposed in the first shell 2100. The first shell 2100 has an upper cavity 2110 and a lower cavity 2120, and the upper cavity 2110 is connected to the primary separation mechanism 1000. The acceleration mechanism 2200 has an acceleration channel, which connects the upper cavity 2110 and the lower cavity 2120. The acceleration channel is also configured to accelerate the gas in the primary treatment product so that the liquid in the primary treatment product is dispersed into droplets and sprayed into the lower cavity 2120.

[0054] In the secondary separation mechanism 2000, the cross-sectional area of the acceleration channel is smaller than the cross-sectional area of the upper cavity 2110. Therefore, when the primary treatment product enters the lower cavity 2120 from the upper cavity 2110 via the acceleration channel, the gas in the primary treatment product is accelerated in the acceleration channel. The accelerated gas impacts the liquid in the primary treatment product, thereby causing the liquid therein to be dispersed into droplets. When the droplets move in the lower cavity 2120, their contact area with the gas is greatly increased, which accelerates the mass transfer rate of volatile organic compounds in the liquid, realizes the rapid volatilization of volatile organic compounds, and improves the removal efficiency of volatile organic compounds. In this way, the volatile organic compounds in the secondary treatment product entering the tertiary separation mechanism 3000 are greatly reduced. Since the volatilized volatile organic compounds remain in the lower cavity 2120 of the first shell 2100 and will not enter the external environment, the pollution to the environment is reduced.

[0055] The solid powder content in the primary treatment product obtained after the waste is treated by the primary separation mechanism 1000 is extremely low. Therefore, the components in the primary treatment product other than gas are collectively referred to as liquids in the following text.

[0056] Next, the detailed structure of each component of the waste treatment system will be introduced. It should be noted that the following only describes a preferred embodiment, which is not the only implementation method and should not constitute an undue limitation to the present invention.

[0057] refer to Figure 1 , and combined with Figures 2 to 4 The primary separation mechanism 1000 includes a cyclone distributor 1100 and a negative pressure filter 1200 disposed at the lower end of the cyclone distributor 1100. The cyclone distributor 1100 is used to centrifuge the waste to remove a portion of the gas in the waste and obtain a primary treatment product, and the primary treatment product enters the negative pressure filter 1200. The negative pressure filter 1200 is used to perform negative pressure filtration on the primary treatment product to remove at least a portion of the solid powder therein and obtain the primary treatment product. It can be understood that the negative pressure filter 1200 has a second outlet, and the second outlet is connected to the upper cavity 2110 of the secondary separation mechanism 2000 through a pipeline. The primary treatment product reaches the secondary separation mechanism 2000 via the second outlet and the pipeline.

[0058] Optionally, the swirl distributor 1100 includes a second shell 1110 and a plurality of suppression baffles 1120. The second shell 1110 has a second inner cavity 1111 extending vertically therethrough, and the cross-section of the second inner cavity 1111 is circular. A third inlet 1112 is provided on the sidewall of the second shell 1110, and the axis of the third inlet 1112 is parallel to a tangent line of the second shell 1110 at the third inlet 1112. The plurality of suppression baffles 1120 are disposed in the second inner cavity 1111 and below the third inlet 1112. The plurality of suppression baffles 1120 are spaced apart circumferentially around the second inner cavity 1111, and each of the suppression baffles 1120 extends radially of the second inner cavity 1111.

[0059] The second inner chamber 1112 is actually divided into two upper and lower sections: the upper section is the cyclone chamber, and the lower section is the suppression chamber. The suppression baffle 1120 is located within the suppression chamber, and the third inlet is located in the portion of the second housing 1110 corresponding to the cyclone chamber. During operation, waste enters the cyclone chamber tangentially through the third inlet 1112, generating a rotating flow field within the cyclone chamber. Furthermore, the various components in the waste generate different centrifugal forces in the cyclone chamber, wherein a portion of the gas with a smaller density forms an inner vortex in the axially upward direction and is discharged from the upper end of the second inner cavity 1111, and another portion of the gas, liquid, and solid powder with a larger density constitutes a primary treatment product, which forms an outer vortex in the axially downward direction and is blocked by the suppression baffle 1120 and stops rotating when it reaches the suppression chamber (that is, the suppression baffle 1120 suppresses the cyclone of the primary treatment product), and then the primary treatment product moves downward along the suppression baffle 1120 and flows out of the cyclone distributor 1100 and enters the negative pressure filter 1200.

[0060] Preferably, the plurality of suppression baffles 1120 are aligned axially of the second inner cavity 1111 and are evenly spaced circumferentially around the second inner cavity 1111. This allows for uniform swirl suppression of the primary treated product around the circumference of the second inner cavity 1111, allowing the primary treated product to enter the filter cloth of the negative pressure filter 1200 more evenly and stably. The number of suppression baffles 1120 may be 2-4.

[0061] In order to ensure that the primary separation mechanism 1000 works effectively, the parameters of the various components of the cyclone distributor 1100 and the parameters of the negative pressure filter 1200 are reasonably set.

[0062] The equivalent diameter D2 of the third inlet 1112 and the diameter D1 of the second inner cavity 1111 must be set to ensure both the formation of a vortex in the waste and an appropriate pressure drop, ensuring smooth flow of the waste components. In practice, the ratio of the equivalent diameter D2 of the third inlet 1112 to the diameter D1 of the second inner cavity 1111 can be 1:5-1:2.

[0063] When setting the axial length L1 of the second inner cavity 1111, it is necessary to comprehensively consider the gas-liquid ratio of the waste, the diameter D1 of the second inner cavity 1111, and the space occupied by the swirl distributor 1100. It is necessary to ensure that the waste can smoothly generate a swirl and undergo centrifugal separation, while not having an excessively large height. Usually, the ratio of the axial length L1 of the second inner cavity 1111 to the diameter D1 of the second inner cavity 1111 can be 1:2-1:9.

[0064] When setting the axial length L2 of the suppression baffle 1120 in the second inner cavity 1111, on the one hand, it is necessary to ensure that the suppression baffle 1120 can effectively suppress the swirl flow, and on the other hand, it cannot occupy too much space in the second inner cavity 1111, otherwise the waste centrifugation time will be short and the gas separation will be insufficient. In practice, the axial length L2 of the swirl baffle 1120 in the second inner cavity 1111 can be 10mm-1000mm. In addition, the ratio of the radial length L3 of the suppression baffle 1120 in the second inner cavity 1111 to the diameter of the second inner cavity 1111 is 0.1:1-0.3:1. The principle of its setting is mainly to effectively suppress the swirl flow.

[0065] For the negative pressure filter 1200 , the aperture of the filter holes on the filter cloth is mainly set according to the content of the oil phase substance in the liquid-solid mixture, which will be described in detail later.

[0066] Furthermore, when the primary treated product enters the negative pressure filter 1200 from the cyclone distributor 1100, a portion of the gas in the primary treated product may overflow. In order to prevent the gas discharged from the cyclone distributor 1100 and the gas overflowing from the primary treated product from being directly discharged into the atmosphere, in this embodiment, the primary separation mechanism 1000 preferably further includes a cover 1300, which is arranged to cover the outside of the cyclone distributor 1100 and the negative pressure filter 1200. The cover 1300 is provided with a third outlet 1310 and a fourth outlet 1320. The third outlet 1310 is connected to a vacuum pump 4000 through a pipeline, and the vacuum pump 4000 can extract the gas in the cover 1300. The fourth outlet 1320 is for the pipeline connecting the negative pressure filter 1200 and the secondary separation mechanism 2000 to pass through. In addition, the cover body 1300 is further provided with a sixth outlet 1330 , and the sixth outlet 1330 is used to discharge the solid powder retained on the filter cloth.

[0067] Please continue to refer to Figure 1 Combined with Figure 5The first shell 2100 has a first inner cavity (not marked in the figure). The acceleration mechanism 2200 includes a partition 2210 and at least one acceleration core tube 2220. The partition 2210 is arranged in the first inner cavity and is connected to the first shell 2100. The partition 2210 divides the first inner cavity into the upper cavity 2110 and the lower cavity 2120. The acceleration core tube 2220 is arranged on the partition 2210. The acceleration core tube 2220 includes a main tube 2221 and an ejection tube 2222 that are coaxially connected. The upper end of the main tube 2221 is located in the upper cavity 2110, and the ejection tube 2222 is located in the lower cavity 2120. The accelerating core tube 2220 has a third inner cavity that passes through the main tube 2221 and the ejection tube 2222. The third inner cavity of each accelerating core tube 2220 constitutes an accelerating channel, and the inner diameter of the third inner cavity at the ejection tube 2222 gradually increases as it moves away from the main tube 2221. The upper end opening of the accelerating core tube 2221 forms a first inlet 2223 for gas to enter the third inner cavity. The side wall of the main tube 2221 also defines a second inlet 2224 for liquid to enter the third inner cavity. This second inlet is located within the upper cavity 2110. The lower end opening of the accelerating core tube 2221 forms a first outlet 2225 for liquid droplets to be ejected.

[0068] In practice, the acceleration core tube 2220 has a circular cross-section, resulting in a circular first inlet 2223 and a circular droplet ejection outlet. In this embodiment, the diameter of the first inlet 22223, i.e., the diameter of the third lumen at the main tube 2221, is d1, which is 6 mm to 30 mm. The area of the second inlet 2224 is 0.00001 m2 to 0.0001 m2. Furthermore, the ratio of the maximum diameter d2 of the third lumen (i.e., the diameter of the first outlet 2225) to the minimum diameter d1 is 1.1-2. The acute angle α formed between the inner sidewall of the ejection tube 2222 and the axis of the acceleration core tube 2220 is 2.5° to 10°. The design of the first inlet 2223 prevents clogging and prevents liquid from the primary treated product from entering the main tube 2221 through the first inlet 2223. The size of the second inlet 2224 is designed to prevent blockage while ensuring that the liquid in the primary treatment product can enter the main pipe 2221 through the second inlet 2224. The size of the two inlets, combined with the acute angle α and the maximum diameter d2 of the third inner cavity, ensures that the liquid in the primary treatment product can be smoothly sprayed into the lower cavity after forming droplets.

[0069] The distance S from the lower end of the ejection pipe 2222 to the bottom of the lower cavity 2120 is set according to the temperature of the liquid-solid mixture. Specifically, when the temperature of the liquid-solid mixture is 5°C-20°C, the distance S is 0.9m-1.5m; when the temperature of the liquid-solid mixture is 20°C-35°C, the distance S is 0.4m-0.9m; when the temperature of the liquid-solid mixture is 35°C-50°C, the distance S is 0.2m-0.4m; and when the temperature of the liquid-solid mixture is greater than 50°C, the distance S is 0.2m.

[0070] It is worth noting that for the same scrubbing tower, the temperature of the waste discharged therefrom varies in different seasons. For example, in winter, the temperature of the liquid-solid mixture is 20°C, while in summer, the temperature of the liquid-solid mixture is 50°C. In this case, to ensure that the same secondary separation mechanism can be used year-round, the distance S should be set based on the temperature of the liquid-solid mixture being 20°C. Of course, if cost is not a consideration, secondary separation mechanisms with different distances S may also be selected in different seasons.

[0071] The three-stage separation mechanism 3000 used in the embodiment of the present invention can be any suitable gas-liquid separation device in the prior art. The liquid separated by the three-stage separation mechanism 3000 is discharged to a sewage treatment plant or reused. The three-stage separation mechanism 3000 is provided with a fifth outlet 3001 for gas outflow, and the fifth outlet 3001 is connected to the vacuum pump 4000 through a pipeline so that the gas separated by the three-stage separation mechanism 3000 can be extracted by the vacuum pump 4000. The gas extracted by the vacuum pump 4000 can be discharged to a combined power plant combustion furnace for further combustion, or discharged to an adsorption chamber for purification using activated carbon provided in the adsorption chamber.

[0072] Typically, the suction volume flow rate of the vacuum pump 4000 is 20 to 40 times the volume flow rate of the waste. The gas flow rate entering the vacuum pump 4000 from the housing 1340 is 5% to 40% of the suction volume flow rate of the vacuum pump 4000. The gas flow rate entering the vacuum pump 4000 from the three-stage separation mechanism 3000 is equal to the suction volume flow rate of the vacuum pump 4000 minus the gas flow rate entering the vacuum pump 4000 from the housing 1340.

[0073] Furthermore, an embodiment of the present invention also provides a waste treatment method for treating the waste discharged from the scrubbing tower, which specifically includes the following steps S10, S20, and S30. Step S10 includes performing a primary separation on the waste to remove a portion of gas and at least a portion of solid powder in the waste, and obtaining a primary treatment product. Step S20 includes performing a secondary separation on the primary treatment product to remove at least a portion of volatile organic compounds in the primary treatment product, and obtaining a secondary treatment product. Step S30 includes performing a gas-liquid separation on the secondary treatment product.

[0074] The step S20 specifically includes: accelerating the gas in the primary treatment product, using the accelerated gas to form dispersed droplets in the liquid in the primary treatment product, and moving the droplets downward a predetermined distance.

[0075] Alternatively, the aforementioned waste treatment system may be used to perform the waste treatment method. Therefore, the primary separation operation is performed by the primary separation mechanism 1000 , and the secondary separation operation is performed by the secondary separation mechanism 2000 .

[0076] Then, the primary separation actually includes steps S11 and S12 performed by the cyclone separator 1100, and step S13 performed by the negative pressure filter 1200. Step S11 includes centrifuging the waste to separate a portion of the gas in the waste and obtain a primary treatment product in a cyclonic state. Step S12 includes using the suppression baffle 1120 to stop the cyclonic flow of the primary treatment product and allow the primary treatment product to flow vertically downward into the negative pressure filter 1200. Step S13 includes using the negative pressure filter 1200 to perform negative pressure filtration on the primary treatment product to remove solid powder and obtain the primary treatment product.

[0077] During centrifugal separation, the total flow velocity V0 of the waste entering the cyclone distributor 1100 from the third inlet 1112 is 0.5 m / s-50 m / s. The superficial velocity V1 of the liquid-solid mixture is 0.04 m / s-0.5 m / s, and the centrifugal acceleration a is 5 to 500 times the acceleration of gravity. Wherein, V0 = (gas flow from the scrubber + flow of the liquid-solid mixture from the scrubber) / (0.25*π*D1 2 ), V1=the flow rate of the liquid-solid mixture from the washing tower / (0.25*π*D2 2 ), a=2*(V0 2 / D2).

[0078] When executing step S13, the oil phase substance in the liquid-solid mixture will adhere to the filter holes of the filter cloth of the negative pressure filter 1200. If the pore size of the filter holes is too small, it will be easily clogged, affecting the separation effect. Therefore, in practice, it is necessary to control the pore size of the filter holes on the filter cloth according to the content of the oil phase substance in the liquid-solid mixture. In addition, the flow rate of the primary treatment product on the filter cloth should also be reasonably controlled according to the content of the oil phase substance in the liquid-solid mixture, so that the residence time of the primary treatment product on the filter cloth matches the content of the oil phase substance and the pore size of the filter holes, and the bridging effect between the particles is utilized to enhance the filtration effect and achieve the best separation effect.

[0079] Specifically, when the content of the oil phase substance in the liquid-solid mixture is 0-1 mg / L, the pore size of the filter cloth is 0.2-0.5 times the Sauter mean diameter of the solids in the waste, and the apparent flow velocity V2 of the primary treatment product on the filter cloth is 0.002 m / s-0.004 m / s. When the content of the oil phase substance in the liquid-solid mixture is 1-100 mg / L, the pore size of the filter cloth is 0.5-1 times the Sauter mean diameter of the solids in the waste, and the apparent flow velocity V2 of the primary treatment product on the filter cloth is 0.001 m / s-0.002 m / s. When the content of the oil phase substance in the liquid-solid mixture is greater than 100 mg / L, the pore size of the filter cloth is 1-1.5 times the Sauter mean diameter of the solids in the waste, and the apparent flow velocity V2 of the primary treatment product on the filter cloth is less than or equal to 0.001 m / s. It can be understood that V2 is equal to the ratio of the flow rate of the liquid-solid mixture from the washing tower to the area of the filter cloth.

[0080] During secondary separation, the superficial velocity V3 of the gas in the primary processed product within the first inner cavity is between 0.1 m / s and 1 m / s, and the superficial velocity V4 of the gas in the primary processed product within the acceleration channel is between 30 m / s and 80 m / s. The superficial velocity V5 of the liquid in the primary processed product within the first inner cavity is less than or equal to 0.1 m / s. V3 is equal to the superficial velocity of the gas in the primary processed product within the first inner cavity, which is equal to the ratio of the gas flow rate entering the first inner cavity from the negative pressure filter 1200 to the cross-sectional area of the first inner cavity. It should be understood that the gas separated by the tertiary separation mechanism 3000 is entirely derived from the primary processed product. Therefore, the gas flow rate flowing from the tertiary separation mechanism 3000 into the vacuum pump 4000 can be considered to be the gas flow rate flowing from the negative pressure filter 1200 into the first inner cavity. V4 is equal to the ratio of the gas flow rate entering the first inner cavity from the negative pressure filter 1200 to the sum of the equivalent diameters of all the acceleration channels. The sum of the equivalent diameters of all the accelerating channels is equal to the product of the equivalent diameter of each accelerating core tube 2200 and the number of accelerating core tubes 2200. V4 is equal to the ratio of the liquid flow rate from the scrubber to the cross-sectional area of the first inner cavity.

[0081] In the secondary treatment, the predetermined distance of the droplet movement is actually equal to the distance S between the lower end of the ejection pipe and the bottom of the lower cavity.

[0082] Next, this article describes the effects of the waste treatment system and method of the present invention with reference to several embodiments and comparative examples. Example 1

[0083] In this embodiment, the particle size of the solid particles in the liquid-solid mixture is 40 μm-400 μm, the average Sauter diameter is 100 μm, and the density is 0.887 g / ml. The flow rate of the liquid-solid mixture is about 10 m 3 / h. The temperature of the liquid-solid mixture in summer is about 60° C., and the temperature of the liquid-solid mixture in winter is about 20° C. The content of the oil phase substance in the liquid-solid mixture is 11 mg / L.

[0084] The parameters of the various components of the waste treatment system are set according to the parameters of the waste. Specifically, the suction volume flow rate of the vacuum pump 4000 is 30 times the flow rate of the liquid-solid mixture, that is, the suction flow rate of the vacuum pump 4000 is 300m 3 / L, the gas flow rate from the cover 1340 into the vacuum pump 4000 accounts for 33% of the suction flow rate of the vacuum pump 4000, and the gas flow rate from the three-stage separation mechanism 3000 into the vacuum pump 4000 is 200Nm 3 / h. The ratio of the equivalent diameter D2 of the third inlet 1112 to the diameter D1 of the second inner cavity 1111 is 1:2.5, and the third inlet 1112 is located at 1 / 2 the height of the second shell 1110. The ratio of the axial length L1 of the second inner cavity 1111 to the diameter D1 of the second inner cavity 1111 is 2. The axial length L2 of the suppression baffle 1120 in the second inner cavity 1111 is 50 mm, the radial length L3 of the suppression baffle 1120 in the second inner cavity 1111 is 40 mm, and the number of the suppression baffles 1120 is 4. The distance from the lower end of the ejection pipe 2222 to the bottom of the lower cavity 2120 is 0.9 m. The diameter d1 of the first inlet 2223 is 20 mm, and the area of the second inlet 2224 is 0.00002 m 2 The acute angle α is 5°, and the ratio of the maximum diameter d2 to the minimum diameter d1 of the third inner cavity is 1.3, that is, 26 mm.

[0085] During operation, the total flow velocity V0 of the waste at the third inlet is 10 m / s, the apparent flow velocity V1 of the liquid-solid mixture in the first inner cavity 1111 is 0.088 m / s, and the centrifugal acceleration is 100 times the acceleration of gravity. The apparent flow velocity V2 of the primary treatment product on the filter cloth of the negative pressure filter 1200 is 0.00139 m / s, and the pore size of the filter cloth is 0.8 times the Sauter mean diameter of the solid powder, that is, 80 μm. The apparent flow velocity V3 of the gas in the primary treatment product in the first inner cavity is 0.28 m / s, the apparent flow velocity V4 of the gas in the primary treatment product in the acceleration channel is 35.4 m / s, and the apparent flow velocity V5 of the liquid in the primary treatment product in the first inner cavity is 0.014 m / s.

[0086] The concentration of volatile organic compounds in the liquid discharged after treatment by the waste treatment system is 0.8 ppm, meeting environmental protection requirements. Furthermore, the residual solid powder in the treated liquid is less than 120 ppm for particles larger than 40 μm, achieving a separation efficiency of 96%. The residual solid powder larger than 100 μm is less than 10 ppm, achieving a separation efficiency of 99%.

[0087] In this embodiment, the particle size of the solid powder was measured using a Malvern particle size analyzer (Master 3000). The concentration of volatile organic compounds was determined using the purge and trap gas chromatography method according to HJ686-2014, Determination of Volatile Organic Compounds in Water. Example 2

[0088] The difference between this comparative example and Example 1 is that the content of the oil phase substance in the liquid-solid mixture is 0.3 mg / L, the apparent flow velocity V2 of the primary treatment product on the filter cloth of the negative pressure filter 1200 is 0.0025 m / s, and the pore diameter of the filter holes of the filter cloth is 0.4 times the average diameter of the solid powder.

[0089] The residual amount of solid powder with a particle size of more than 40um in the liquid obtained after treatment does not exceed 50ppm, with a separation rate of 98%. The residual amount of solid powder with a particle size of more than 100um is 5ppm, with a separation rate as high as 99.9%.

[0090] When the oil content in the waste is low, the apparent flow velocity V2 of the primary treatment product on the filter cloth of the negative pressure filter is smaller, the pore size of the filter holes of the filter cloth is also smaller, and the separation effect of the solid powder is better.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that the superficial velocity V4 of the gas in the primary treatment product in the acceleration channel is 20 m / s, and the diameter d1 of the first inlet is 60 mm.

[0093] The concentration of volatile organic compounds in the treated liquid was 20 ppm. This result was caused by the fact that the liquid in the primary treatment product did not form droplets in the secondary separation mechanism, resulting in a small mass transfer area and low volatile component removal efficiency.

[0094] Comparative Example 2

[0095] The difference between this comparative example and Example 1 is that no cyclone distributor is provided, that is, the waste is not centrifuged.

[0096] The reason why the entire treatment process cannot be stabilized is that the gas content in the waste is large, and the waste directly impacts the filter cloth of the negative pressure filter, causing the waste to splash and the negative pressure filter to be unable to operate normally.

[0097] Comparison Three

[0098] The difference between this comparative example and Example 1 is that the lowest temperature of the waste is 20° C., and the distance from the lower end of the ejection pipe 2222 to the bottom of the lower cavity 2120 is 0.2 m.

[0099] The volatile organic compound content in the treated liquid was 90 ppm. This result was caused by insufficient vertical movement of the droplets formed by the primary treatment product, resulting in a short mass transfer time and ineffective separation of the volatile organic compounds.

[0100] While the present invention is disclosed above, it is not limited thereto. Those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to encompass such modifications and variations as long as they fall within the scope of the claims and their equivalents.

Claims

1. A waste treatment system, wherein the waste comprises a liquid-solid mixture and a gas, and the liquid-solid mixture comprises water, volatile organic compounds and solid powder, characterized in that: The waste treatment system comprises: A primary separation mechanism, for removing part of the gas and at least part of the solid powder in the waste and obtaining a primary treated product; the primary separation mechanism comprises a cyclone distributor and a negative pressure filter, the cyclone distributor comprising a second shell and a plurality of suppression baffles, and the negative pressure filter is disposed at the lower end of the cyclone distributor; A secondary separation mechanism for removing at least part of the volatile organic compounds in the primary treatment product and obtaining a secondary treatment product; the secondary separation mechanism comprises a first shell and an acceleration mechanism arranged in the first shell, the first shell having an upper cavity and a lower cavity, the upper cavity being connected to the primary separation mechanism; the acceleration mechanism has an acceleration channel, the acceleration channel being connected to the upper cavity and the lower cavity, the acceleration channel being configured to accelerate the gas in the primary treatment product, thereby causing the liquid in the primary treatment product to disperse into droplets and spray into the lower cavity; wherein the first shell has a first inner cavity; the acceleration mechanism comprises a partition and at least one acceleration core tube; the partition is arranged in the first inner cavity, and the first inner cavity is divided into The cam is divided into the upper cavity and the lower cavity; the accelerating core tube is arranged on the partition and includes a main tube and an ejection tube arranged coaxially, the upper end of the main tube is located in the upper cavity, and the ejection tube is located in the lower cavity; the accelerating core tube has a third inner cavity that passes through the main tube and the ejection tube, and the inner diameter of the third inner cavity at the ejection tube gradually increases in the direction away from the main tube, and the third inner cavity of each accelerating core tube constitutes an accelerating channel; the upper end opening of the accelerating core tube constitutes a first inlet for gas to enter the third inner cavity, and a second inlet for liquid to enter the third inner cavity is provided on the side wall of the main tube, and the second inlet is located in the upper cavity. The lower end opening of the accelerating core tube constitutes a first outlet for liquid droplets to be ejected; and, The tertiary separation mechanism is connected to the lower cavity and is used for performing gas-liquid separation on the secondary treatment product.

2. The waste treatment system according to claim 1, characterized in that: The cross section of the third inner cavity is circular, the minimum diameter of the third inner cavity is 6mm-30mm, and the ratio of the maximum diameter to the minimum diameter of the third inner cavity is 1.1-2; the area of the second inlet is 0.00001m 2 -0.0001m 2 The acute angle formed by the wall of the third inner cavity at the ejection tube and the axis of the accelerating core tube is 2.5°-10°.

3. The waste treatment system according to claim 1, characterized in that: The second shell has a second inner cavity extending through in the vertical direction, and the cross-section of the second inner cavity is circular; a third inlet is provided on the side wall of the second shell, and the axis of the third inlet is parallel to the tangent of the second shell at the third inlet; a plurality of suppression baffles are arranged in the second inner cavity and are located below the third inlet, and the plurality of suppression baffles are arranged at intervals along the circumference of the second inner cavity, and each of the suppression baffles extends radially along the second inner cavity; the negative pressure filter has a second outlet for the outflow of the primary treatment product, and the second outlet is connected to the upper cavity of the secondary separation mechanism through a pipeline.

4. The waste treatment system according to claim 3, characterized in that: The plurality of suppression baffles are aligned in the axial direction of the second inner cavity, and the plurality of suppression baffles are evenly arranged in the circumferential direction of the second inner cavity.

5. The waste treatment system according to claim 3, characterized in that: The ratio of the equivalent diameter of the third inlet to the diameter of the second inner cavity is 1:5-1:2; the ratio of the axial length of the second inner cavity to the diameter of the second inner cavity is 1:2-1:9; the ratio of the radial length of the suppression baffle in the second inner cavity to the diameter of the second inner cavity is 0.1:1-0.3:

1.

6. The waste treatment system according to claim 3, characterized in that: The primary separation mechanism further includes a cover body, which is arranged outside the cyclone distributor and the negative pressure filter, and is provided with a third outlet and a fourth outlet. The third outlet is connected to a vacuum pump through a pipeline, and the fourth outlet is provided for a pipeline connecting the second outlet of the negative pressure filter and the upper cavity of the secondary separation mechanism. The three-stage separation mechanism has a fifth outlet for gas circulation, and the fifth outlet is connected to the vacuum pump.

7. A method for treating waste, wherein the waste comprises a liquid-solid mixture and a gas, and the liquid-solid mixture comprises water, volatile organic compounds and solid powder, characterized in that: The treatment method is performed based on the waste treatment system according to any one of claims 1 to 6, and the treatment method comprises the following steps: performing primary separation on the waste to remove a portion of gas and at least a portion of solid powder, and obtain a primary treatment product; performing secondary separation on the primary treatment product to remove at least a portion of volatile organic compounds and obtain a secondary treatment product; as well as, The secondary treatment product is subjected to gas-liquid separation; wherein, The secondary separation includes: accelerating the gas in the primary treatment product, using the accelerated gas to disperse the liquid in the primary treatment product into droplets, and moving the droplets downward a predetermined distance.

8. The waste treatment method according to claim 7, characterized in that: The primary treatment product is subjected to secondary separation using a secondary separation mechanism, the secondary separation mechanism comprising a first shell and an acceleration mechanism, the first shell having a first inner cavity, the first inner cavity being divided by the acceleration mechanism into an upper cavity and a lower cavity, the upper cavity being used to receive the primary treatment product; the acceleration mechanism having an acceleration channel, the acceleration channel communicating with the upper cavity and the lower cavity, and the acceleration channel being configured to accelerate gas in the primary treatment product, thereby causing liquid in the primary treatment product to disperse into droplets and spray into the lower cavity; The apparent flow velocity of the gas in the primary treatment product in the first inner cavity is 0.1m / s-1m / s, and the apparent flow velocity of the gas in the primary treatment product in the acceleration channel is 30m / s-80m / s; the apparent flow velocity of the liquid in the primary treatment product in the first inner cavity is less than or equal to 0.1m / s.

9. The waste treatment method according to claim 7, characterized in that: When the temperature of the liquid-solid mixture is 5°C-20°C, the predetermined distance is 0.9m-1.5m; When the temperature of the liquid-solid mixture is 20°C-35°C, the predetermined distance is 0.4m-0.9m; When the temperature of the liquid-solid mixture is 35°C-50°C, the predetermined distance is 0.2m-0.4m; When the temperature of the liquid-solid mixture is greater than 50° C., the predetermined distance is 0.2 m.

10. The waste treatment method according to claim 7, characterized in that: The primary separation includes: centrifuging the waste to separate part of the gas in the waste and obtaining a primary treatment product in a cyclonic state; Controlling the primary treatment product to stop the swirling flow and allowing the primary treatment product to flow vertically downward into the negative pressure filter; and, The primary treatment product is subjected to negative pressure filtration to separate at least part of the solid powder in the primary treatment product and obtain the primary treatment product.

11. The waste treatment method according to claim 10, characterized in that: The primary treatment product is subjected to negative pressure filtering using a negative pressure filter, wherein the negative pressure filter comprises a filter cloth; the liquid-solid mixture comprises an oil phase substance; When the content of the oil phase substance in the liquid-solid mixture is 0-1 mg / L, the pore size of the filter pores on the filter cloth is 0.2-0.5 times the Sauter mean diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is 0.002 m / s-0.004 m / s; When the content of the oil phase substance in the liquid-solid mixture is 1-1000 mg / L, the pore size of the filter pores on the filter cloth is 0.5-1 times the Sauter mean diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is 0.001 m / s-0.002 m / s; When the content of the oil phase substance in the liquid-solid mixture is greater than 1000 mg / L, the pore size of the filter holes on the filter cloth is 1-1.5 times the Sauter average diameter of the solid powder in the waste, and the apparent flow velocity of the primary treatment product on the filter cloth is less than or equal to 0.001 m / s.

12. The waste treatment method according to claim 10, characterized in that: centrifugally separating the waste using a cyclone distributor; The flow velocity of the waste when entering the cyclone distributor is 0.5m / s-50m / s. During centrifugal separation, the superficial velocity of the liquid in the waste is 0.04m / s-0.5m / s, and the centrifugal acceleration is 5 times to 500 times the acceleration of gravity.

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