Non-ferrous processing waste emulsion low temperature evaporation treatment method and system

Abstract

The present application relates to a kind of non-ferrous metal processing waste emulsion low-temperature evaporation treatment method and system, solve how to improve water treatment effect problem.Provide a kind of non-ferrous metal processing waste emulsion low-temperature evaporation treatment method, comprising: S1, pretreatment, the surface oil slick and dross of waste emulsion are collected;S2, low-temperature evaporation, after precision filtration waste emulsion is heated in vacuum environment, make the water in waste emulsion evaporate to separate from waste emulsion, and steam is condensed into water, the concentrated solution after waste emulsion evaporation is collected;S3, subsequent treatment, using activated carbon filter condensate water.Provide a kind of non-ferrous metal processing waste emulsion low-temperature evaporation treatment system, comprising sequentially connected: waste emulsion conditioning tank, oil and dross removal device, precision filtration device, low-temperature evaporation device, activated carbon filter device.Compared with reagent demulsification process, this process does not need to add various demulsifiers and acid and alkali, final effluent conductivity is low, system does not produce sludge, no secondary pollution.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, specifically the field of waste emulsion treatment in non-ferrous metal processing, and particularly relates to a low-temperature evaporation treatment method and system for waste emulsion in non-ferrous metal processing. Background Technology

[0002] Emulsions are lubricants used to assist in the lubrication and cooling of non-ferrous metals during processes such as drawing, hot rolling, grinding, and cutting. Emulsions are typically composed of pure water, base oil, and surfactants. To maintain the stability of the oil's appearance and achieve specific functions during use, various additives (such as rust inhibitors, extreme pressure additives, friction modifiers, and antioxidants) are often added. Emulsions are recycled. With continuous recycling, impurities such as lubricating oil, engine oil, and metal shavings enter the emulsion. Simultaneously, the surfactants and other additives denature, leading to varying degrees of rancidity, which degrades the quality of the emulsion and affects product quality. Therefore, emulsions must be discarded and replaced with fresh emulsion according to production conditions to ensure smooth production.

[0003] The discarded emulsion and waste emulsion, apart from the black floating oil on the surface, are grayish-white in general. Due to the action of surfactants, the machine oil is still highly dispersed in the water, and the emulsion system is stable. Traditional chemical demulsification, electrolytic demulsification, acid demulsification, ceramic membrane filtration and other methods have problems such as poor demulsification effect, unstable operation, and high operating intensity, and the results are not satisfactory. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing, which solves the problem of how to improve water treatment efficiency.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing, comprising: S1. Pretreatment: collect floating oil and scum on the surface of the waste emulsion, filter the collected material to separate the scum, concentrate the floating oil obtained after filtration, and perform precision filtration on the waste emulsion after oil and scum removal to further remove particulate matter from the waste emulsion. S2. Low-temperature evaporation: The finely filtered waste emulsion is heated in a vacuum environment to evaporate the water in the waste emulsion and separate it from the waste emulsion. The steam is condensed into water, and the concentrated liquid after evaporation of the waste emulsion is collected. S3. Subsequent treatment: use activated carbon to filter the condensate.

[0006] Preferably, in S2, a compressor is used to compress the refrigerant from gas to liquid, and the compressed refrigerant exchanges heat with the waste emulsion to heat and evaporate the waste emulsion. An expansion valve is used to convert the refrigerant from liquid to gas, and the converted gas exchanges heat with steam to condense the steam.

[0007] Preferably, in S2, the evaporation is carried out in a vacuum state by heating the waste emulsion to boiling point through electric heating, steam, or boiler waste heat. The steam generated by evaporation then passes through a coil for heat exchange, and the steam is condensed into liquid water by the cold water in the coil.

[0008] Preferably, in S1, the collection of floating oil and scum on the surface of the waste emulsion is carried out using a float ball with a suction head that can float on the surface of the waste emulsion.

[0009] A low-temperature evaporation treatment system for waste emulsion from non-ferrous metal processing is also provided, comprising the following components connected in sequence: Waste emulsion equalization tank; The oil and sludge removal device includes an oil and sludge collection mechanism, a filtration mechanism for filtering sludge, and a concentration mechanism for concentrating oil. A precision filtration device is used to filter waste emulsion after oil and sludge removal in order to further remove particulate matter; A low-temperature evaporation device includes an evaporator, a condenser, and a vacuuming mechanism for evacuating the evaporator. The evaporator is connected to the outlet of the precision filter and is used for low-temperature evaporation of pretreated waste emulsion. The condenser is connected to the steam outlet of the evaporator to condense the steam into water. An activated carbon filtration device is used to filter condensate.

[0010] Preferably, the oil and scum collection mechanism includes a float and a suction head for extraction.

[0011] Preferably, the low-temperature evaporation device includes a liquid inlet pump, which is capable of supplying liquid according to the evaporation status of the evaporation tank.

[0012] Preferably, the low-temperature evaporation device includes a refrigerant circulation mechanism, which includes a circulation pipe, a compressor, an expansion valve, and refrigerant disposed in the circulation pipe. The compressor is used to compress the gaseous refrigerant into a liquid state and use the heat released during compression to heat the evaporator. The expansion valve is used to convert the liquid refrigerant into a gas and absorb heat from the condenser.

[0013] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The present invention relates to a low-temperature evaporation treatment method and system for non-ferrous metal processing waste emulsion. The waste emulsion undergoes pretreatment to remove floating oil and scum, and particulate matter is removed after filtration. The pretreated waste emulsion is then subjected to low-temperature evaporation to separate the water content. Compared to chemical demulsification processes, this process does not require the addition of various demulsifiers or acids / alkalis, resulting in low conductivity of the final effluent. The system produces no sludge, avoids secondary pollution, has low operational intensity, and provides a favorable operating environment. Attached Figure Description

[0014] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of the structure of a low-temperature evaporation treatment system for waste emulsion from non-ferrous metal processing according to the present invention; Figure 2 This is a schematic diagram of the structure of the evaporator and condenser in a low-temperature evaporation device; Figure 3 This is a flowchart of the steps of a low-temperature evaporation treatment method for waste emulsion from non-ferrous metal processing according to the present invention; The reference numerals in the attached figures are explained as follows: 1. Waste emulsion conditioning tank; 2. Oil and slag removal device; 21. Waste slag collection tank; 22. Floating oil collection tank; 3. Precision filtration device; 4. Low temperature evaporation device; 41. Evaporator; 42. Condenser; 43. Vacuum pump; 44. Refrigerant circulation mechanism; 441. Compressor; 442. Expansion valve; 443. Evaporator coil; 444. Condenser coil; 445. Circulation pipe; 45. Concentrate collection tank; 5. Intermediate water tank; 6. Activated carbon filtration device; 7. Reclaimed water tank. Detailed Implementation

[0015] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] like Figure 1 The waste emulsion low-temperature evaporation treatment system for non-ferrous metal processing shown includes a waste emulsion conditioning tank 1, an oil and slag removal device 2, a precision filtration device 3, a low-temperature evaporation device 4, an intermediate water tank 5, and an activated carbon filtration device 6.

[0017] The waste emulsion undergoes pretreatment in a waste emulsion equalization tank 1, an oil and slag removal device 2, and a precision filtration device 3 to remove most of the floating oil, slag, and particulate matter. It then passes through a low-temperature evaporation device 4 for low-temperature evaporation, causing the water to evaporate. The evaporated water is then condensed and temporarily stored in an intermediate water tank 5, and subsequently passes through an activated carbon filtration device 6 to remove trace amounts of floating oil. The final treated water can be reused in production.

[0018] Waste emulsion equalization tank 1 is used to temporarily store waste emulsion to be treated.

[0019] The oil and scum collection mechanism (not shown) collects the floating oil and scum from the surface of the waste emulsion. The mechanism includes a float and a suction head. The float floats on the surface of the waste emulsion conditioning tank 1, while the suction head sucks up the surface oil and scum. The sucked-up scum is filtered through a filtration mechanism (not shown) to remove particulate matter. The filtered scum is stored in a waste scum collection tank 21 and cleaned periodically. The sucked-up oil is stored in an oil collection tank 22 and concentrated by a concentration mechanism (not shown) to increase the water content of the collected oil, allowing it to be sold directly to a qualified third party.

[0020] The precision filtration device 3 filters the waste emulsion after oil and slag removal to further remove particulate matter, making the waste emulsion easier to evaporate at low temperature in the future.

[0021] like Figure 2 The low-temperature evaporation device 4 includes an evaporator 41, a condenser 42, and a vacuuming mechanism for evacuating the evaporator 41. The evaporator 41 is connected to the outlet of the precision filter 3 and receives waste emulsion for low-temperature evaporation of the pretreated waste emulsion. An evaporator coil 443 is installed inside the evaporator 41 to facilitate heat exchange between the waste emulsion and the heat medium within the evaporator coil 443. The vacuuming mechanism includes a vacuum pump 43, used to evacuate the evaporator 41, thereby lowering the boiling point of water in the waste emulsion.

[0022] The low-temperature evaporation device 4 includes a liquid inlet pump (not shown in the figure), which can also add liquid according to the evaporation status of the evaporator 41, for example, by installing a liquid level sensor inside the evaporator 41.

[0023] The condenser 42 is connected to the steam outlet of the evaporator 41 to receive steam and condense the steam into water inside the condenser 42. The condenser 42 is equipped with a condenser coil 444 to exchange heat between the steam and the cold medium inside the condenser coil 444.

[0024] The low-temperature evaporation device 4 also includes a refrigerant circulation mechanism 44. The refrigerant circulation mechanism 44 includes a compressor 441, an expansion valve 442, an evaporator coil 443, a condenser coil 444, and a circulation pipe 445.

[0025] Refrigerant is contained in the circulation pipe 445. Heat is released and absorbed through the phase change of the medium. The compressor 441 converts the medium from a gaseous state to a liquid state, a process that releases heat, allowing the hot medium to enter the evaporator coil 443. The expansion valve 442 converts the medium from a liquid state to a gaseous state, a process that absorbs heat, allowing the cold medium to enter the condenser coil 444.

[0026] Cooling water flowing from condenser 42 enters intermediate water tank 5 for collection. After the intermediate water tank 5 collects a certain amount of water, it is then processed further.

[0027] Although this example uses the phase change of refrigerant for heating, in other embodiments, the waste emulsion can also be heated to boiling in a vacuum state by electric heating, steam or boiler waste heat, and then the steam generated by evaporation is heat exchanged through a coil, and the steam is condensed into liquid water by the cold water in the coil.

[0028] The intermediate water tank 5 is connected to the activated carbon filter device 6. The condensate discharged from the condenser tank 42 carries a small amount of floating oil. After being adsorbed by the activated carbon, the produced water has low conductivity and low COD and can be directly reused in production as makeup water for circulating water. The activated carbon is replaced periodically when it is saturated, and the replaced activated carbon is outsourced for treatment.

[0029] The activated carbon filter device 6 is connected to the recycled water tank 7 to collect the water flowing out of the activated carbon filter device 6 for use as replenishment water for the production circulating water.

[0030] like Figure 3 The low-temperature evaporation treatment method for non-ferrous metal processing waste emulsion shown includes: S1. Pretreatment: collect floating oil and scum on the surface of the waste emulsion, filter the collected material to separate the scum, concentrate the floating oil obtained after filtration, and perform precision filtration on the waste emulsion after oil and scum removal to further remove particulate matter from the waste emulsion. S2. Low-temperature evaporation: The finely filtered waste emulsion is heated in a vacuum environment to evaporate the water in the waste emulsion and separate it from the waste emulsion. The steam is condensed into water, and the concentrated liquid after evaporation of the waste emulsion is collected. S3. Subsequent treatment: use activated carbon to filter the condensate.

[0031] This invention employs a low-temperature evaporation process, which, compared to chemical demulsification processes, eliminates the need for various demulsifiers and acids / alkalis. The resulting effluent has low conductivity, produces no sludge, avoids secondary pollution, has low operational intensity, and provides a favorable operating environment. Compared to electrolytic demulsification, it eliminates the need for frequent electrode replacements and the addition of electrolytes to the waste emulsion, resulting in low operational intensity and a favorable operating environment with no sludge production. Compared to inorganic membrane filtration, it offers stable operation, a higher concentration ratio, requires no chemical cleaning, produces no acidic or alkaline wastewater, requires no periodic replacement, has low maintenance costs, and low operational intensity. Compared to MVR evaporation, it has lower energy consumption, a higher concentration ratio, requires no secondary cooling of the effluent, and produces better effluent quality. The entire process is stable, especially the concentration system centered on the low-temperature evaporation unit, which boasts a high degree of automation. The entire system requires no manual chemical preparation, produces no sludge, can be operated unattended, produces stable effluent quality, and has a high concentration ratio of 90%–95%. The effluent can be directly reused in production after activated carbon adsorption, while the concentrate can be outsourced for further treatment.

[0032] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing, characterized in that, include: S1. Pretreatment: collect floating oil and scum on the surface of the waste emulsion, filter the collected material to separate the scum, concentrate the floating oil obtained after filtration, and perform precision filtration on the waste emulsion after oil and scum removal to further remove particulate matter from the waste emulsion. S2. Low-temperature evaporation: The finely filtered waste emulsion is heated in a vacuum environment to evaporate the water in the waste emulsion and separate it from the waste emulsion. The steam is condensed into water, and the concentrated liquid after evaporation of the waste emulsion is collected. S3. Subsequent treatment: use activated carbon to filter the condensate.

2. The method for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing according to claim 1, characterized in that: In S2, a compressor is used to compress the refrigerant from gas to liquid, and the compressed refrigerant exchanges heat with the waste emulsion to heat and evaporate the waste emulsion. An expansion valve is used to convert the refrigerant from liquid to gas, and the converted gas exchanges heat with the vapor to condense the vapor.

3. The method for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing according to claim 1, characterized in that: In S2, evaporation involves heating the waste emulsion to boiling point under vacuum using electric heating, steam, or boiler waste heat. The steam generated by evaporation then exchanges heat through a coil, where it is condensed into liquid water by the cold water inside the coil.

4. The method for low-temperature evaporation treatment of waste emulsion from non-ferrous metal processing according to claim 1, characterized in that: In S1, the floating oil and scum on the surface of the waste emulsion are collected by using a float ball with a suction head that can float on the surface of the waste emulsion.

5. A low-temperature evaporation treatment system for waste emulsion from non-ferrous metal processing, characterized in that, Including those that are sequentially connected: Waste emulsion equalization tank (1); The oil and slag removal device (2) includes an oil and slag collection mechanism, a filtration mechanism for filtering slag, and a concentration mechanism for concentrating oil. A precision filtration device (3) is used to filter the waste emulsion after degreasing and deslagging to further remove particulate matter; The low-temperature evaporation device (4) includes an evaporator (41), a condenser (42), and a vacuuming mechanism for evacuating the evaporator (41). The evaporator (41) is connected to the outlet of the precision filter device (3) for low-temperature evaporation of the pretreated waste emulsion. The condenser (42) is connected to the steam outlet of the evaporator (41) to condense the steam into water. An activated carbon filter device (6) is used to filter condensate.

6. The low-temperature evaporation treatment system for non-ferrous metal processing waste emulsion according to claim 5, characterized in that: The oil and scum collection mechanism includes a float and a suction head for extraction.

7. The low-temperature evaporation treatment system for non-ferrous metal processing waste emulsion according to claim 5, characterized in that: The low-temperature evaporation device (4) includes a liquid inlet pump, which can supply liquid according to the evaporation status of the evaporation tank (41).

8. The low-temperature evaporation treatment system for non-ferrous metal processing waste emulsion according to claim 5, characterized in that: The low-temperature evaporation device (4) includes a refrigerant circulation mechanism (4), which includes a circulation pipe (445), a compressor (441), an expansion valve (442), and a refrigerant disposed in the circulation pipe (445). The compressor (441) is used to compress the gaseous refrigerant into a liquid state and use the heat released during compression to heat the evaporator (41). The expansion valve (442) is used to convert the liquid refrigerant into a gas and absorb heat from the condenser (42).

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