KR100483253B1 - Method for recycling of aqueous cleaner solution and synthetic chemical solution using ozone and system thereof - Google Patents

Abstract

The present invention dilutes the liquid or powder detergent stock solution in the range of 11-13 with water in the range of 3-5% with water to clean the contaminants such as microchips and metal-coating agents on the product through a cleaning apparatus such as ultrasonic or spray method. The present invention relates to a water-soluble alkaline cleaning process, and an apparatus, comprising: an ozone sterilization process in which ozone is sterilized by injecting ozone into a washing tank and / or an oil / water separation tank containing a washing liquid and oil in a contaminated state; The media is filled with a particle removal step of removing the fine metal chips within 20 microns by passing the washing solution and oil sterilized in the ozone sterilization process through a pretreatment filter and a large particle cleaning solution and oil not removed from the particle removal step. Oil removal hole that removes oil by integrating oil particles of about 10-20 microns and floating them up And a concentrated liquid mixing process in which micelle-shaped oil that has not passed through the oil removal process and the membrane filter is passed through the oil removal process, and the mixed solution of the filtrate and the oil is discharged to the membrane filter, and the washing solution purified by the membrane filter. Recirculation process to transfer a part to the washing tank for reuse, and to recycle the remainder to the concentrate mixture process after a certain period of time to the cutting oil concentration tank; The present invention provides a method and apparatus for recycling a cleaning liquid using ozone injection.

As such, the present invention provides an ozone injection process for preventing contamination of the washing tank caused by the microorganism and the occurrence of odor and a decrease in the concentration of the cleaning agent, so the inconvenience of periodically cleaning the membrane filter contaminated with bacteria such as bacteria or fungi. By eliminating the problem and using a membrane filter that is not contaminated, a stable amount of permeate can be secured. In addition, the present invention can be reused after removing the cutting oil residue because the used cutting oil is separated from the washing liquid in the membrane filter and recirculated. In addition, the present invention provides a control signal input process of measuring the pH of the washing liquid discharged from the membrane filter, converting the measured pH value into an electrical signal and inputting it as a control signal of the cleaning agent inlet control valve, thereby effectively adding the cleaning agent. It can be improved, and the pH concentration of the washing tank can be adjusted constantly.

Description

Method for recycling cutting oil and washing liquid using ozone injection and its device {METHOD FOR RECYCLING OF AQUEOUS CLEANER SOLUTION AND SYNTHETIC CHEMICAL SOLUTION USING OZONE AND SYSTEM THEREOF}

The present invention relates to a cutting oil and a water-soluble washing liquid regeneration apparatus used in the metal processing process, and more particularly, an ozone generator is additionally installed in the aqueous washing liquid regeneration apparatus including a washing tank and an oil / water separation tank, and receives a pH control signal. A valve means is connected and further includes a detergent storage tank for discharging the detergent according to the opening and closing of the valve means. In addition, a concentration of cutting oil is installed in the concentration tank, whereby microorganisms cause contamination of the washing tank and the oil / water separator and odors. In addition, the present invention relates to a cutting oil and washing liquid regeneration apparatus capable of preventing a decrease in the concentration of the washing agent, fundamentally improving the water-soluble washing liquid regeneration process by adjusting the pH condition to the washing agent, and further recirculating the cutting oil to reuse the cutting oil.

Water-soluble alkaline cleaning is a source of contamination such as microchips and metal co-solvents that are deposited on the product through a cleaning device such as ultrasonic or spray method by diluting the liquid or powder detergent solution with a pH of 11-13 to 3-5%. It means a kind of degreasing process to clean.

Various cutting oils, plastic processing oils, grease, rust preventing oils, rolling oils, lubricating oils, etc. are used on the surface of mechanical devices, machine parts after metal processing, electronic circuit boards after printing, and cold rolled steel sheets (hereinafter referred to as 'processed products') during the steel manufacturing process. Impurities such as metal chips, dust, and dirt generated during the process of metal covalent and denatured maintenance phase materials, oxidation scale and rolling are attached. Surface impurities of such various industrial processed products deteriorate the efficiency of the subsequent plating process, coating process, surface treatment process, etc., so it is necessary to wash and remove them beforehand.

Conventionally, CFC (freon) cleaners or chlorine cleaners such as methylene chloride, PCE, and TCE have been used to clean the surface of processed products.Because these cleaners cause environmental damage such as destruction of ozone layer and threat of safety and health, Environmentally friendly water-soluble cleaners have been developed and used in place of these cleaners.

Aqueous washing liquid is an aqueous solution based on alkali or soap component of 5-10% concentration and is known to efficiently remove various contaminants on the surface of processed products. Water-soluble washing liquid is essential to emulsify various oils in water phase. Surfactants, dispersants for dispersing solid particles in the water phase, wetting agents and other additives.

As the water-soluble washing solution is repeatedly used, the content of various metal-covalent metals, metal chips, and the like separated from the processed products increases, and surfactants and dispersants are added to the washing agent to emulsify or disperse them. If the amount of surfactant and dispersant in the cleaning agent and the contaminants associated with them is increased to some extent, an oil film is formed on the surface of the cleaning agent and particles such as metal chips settle to the bottom of the cleaning tank. When this condition is reached discard the aqueous wash solution and replace it with a new one.

However, there is still a considerable amount of cleaning power left in this state of cleaning, which is a waste of resources and money. Furthermore, when discarding the aqueous washing solution containing various surfactants, dispersants and other additives, it is difficult to apply a conventional water treatment system. Therefore, a recycling method has been proposed to reduce the amount of the lung detergent as much as possible or to prevent the generation of the lung detergent at all (US Pat. No. 5,409,613).

The U.S. patent discloses that the detergent component is removed by the membrane having an appropriately selected pore size so as to remove only the various metal-covalent and dispersed particles that are emulsified while being maintained in the aqueous washing solution, thereby repeatedly using the aqueous washing solution. Microfiltration is applied. This will be briefly described with reference to FIG.

The wash basin in which the workpieces are washed is connected to the sump, so that the overflow of the wash basin flows into the sump, so that the amount of detergent in the wash tub is always kept constant. The cleaning agent moved to the sump is recycled to the washing tank if it can be reused as it is, and if purification is required, it is moved to the concentration tank through A indicated in FIG. 3. The metal covalent emulsion and dispersed particles emulsified by the membrane's resolution as the detergent passes through the membrane portion by forced flow from the concentration tank are concentrated and recovered to the concentration tank, and the washing component from which the emulsion and the dispersed particles are removed is passed through B shown in FIG. Move to the wash bath and reuse.

As the recycle cycle progresses in this manner, the concentration of contaminants (metal covalent emulsions, dispersed particles, etc.) in the thickener increases, and metal covalents, such as oil and grease accumulated above the emulsifying capacity of the emulsifier, rise to the surface of the thickener ( That is, the solid particles accumulated above the dispersing capacity of the dispersant) is precipitated to the bottom of the concentration tank. Thus, flotation oil is continuously or periodically separated from the surface of the thickener and periodically removed from the bottom of the thickener.

The US patent invention has made it possible to use an efficient cleaning agent system than the conventional batch water-soluble detergent. However, in the case of the present invention, various sludges, metal particles, metal soaps, floating oils (oils having a particle size of approximately 50-150 μm), physically emulsified oils (not chemically emulsified by surfactants) The oil is physically finely fragmented to form a membrane of fine oil particles (about 10-30 μm in size) that behaves like a colloid in an aqueous solution, which contaminates the membrane and causes fouling, which degrades the membrane's separation ability. . In order to remove such fouling, the present invention adopts a method of periodically backflushing and backwashing the membrane. However, in order to maintain the separation ability of the membrane smoothly, the separation efficiency of the membrane is low due to the short period of backwashing. In addition, the problem that the membrane tissue is damaged by repeated backwash is highlighted. In addition, the US patent invention has a problem in that the total volume of the device is increased because the oil separated by the oil removal system (oiler) separate the floating oil (oiler) separated by the wash liquid classified by the oil removal.

Meanwhile, the applicant has received Korean Patent Registration No. 327166 regarding the reuse of a water-soluble cleaner. Briefly claim 1 of the applicant's patent registration No. 327166,

Particles of 5 µm or more in diameter are precipitated to the bottom of the bath by adding a hard-treatment wastewater or a water-soluble washing liquid, and the oil having a relatively large particle floats. Particle removal process to discharge;

The filtrate passed through the particle removal process causes the oil to be physically emulsified and oil and metal soap of large particles not removed in the particle removal process to float, and the filtrate passing through the through hole at the bottom of the partition is the inner partition of the tank. An oil removal process for discharging to the top of the other space;

Concentrate mixing step of adding a concentrated solution containing the filtrate passed through the oil removal step and the oil emulsion that did not penetrate the membrane in the same amount, and discharges the mixed solution passed through the through hole at the bottom of the partition to the membrane module;

A circulating step of transferring a portion of the purified tablet washing solution purified by the membrane module to a washing tank and recycling the rest to a mixing process;

It can be seen that the pretreatment method for the reuse of the aqueous washing solution containing a (see Fig. 4).

The present invention is to overcome the above-mentioned conventional problems, the object of the present invention is to provide a bacteria such as bacteria or fungi by providing an ozone injection process to prevent contamination of the cleaning tank caused by microorganisms and the resulting odor and reduction of the concentration of the cleaning agent It eliminates the inconvenience of periodically cleaning the contaminated membrane filter and secures a stable amount of permeated water by using an uncontaminated membrane filter.

Another object of the present invention is to measure the pH of the washing liquid discharged from the membrane filter, and provides a control signal input process of converting the measured pH value into an electrical signal and inputting it as a control signal of the cleaning agent inlet control valve. It is to improve efficiently and to constantly adjust the pH concentration of the washing tank.

Method for reusing the washing liquid by ozone injection according to the present invention for achieving the object of the present invention is the bacteria contained in the washing liquid and oil by injecting ozone into the washing tank and / or oil and water separation tank containing the washing liquid and oil in a contaminated state (Ozone sterilization process), the sterilized washing solution and oil are passed through a pre-filter to remove fine metal chips within 20 microns (particle removal process), and then the large particle washing solution and oil that have not been removed In the packed oil and water separation tank, oil particles of about 10-20 microns are coalesced and floated to the top to remove the oil (oil removal process), and the filtrate from which the oil is removed is mixed with the micelle-type oil that cannot pass through the membrane filter. Next, the mixed solution of the filtrate and oil is discharged to the membrane filter (concentrate mixture mixing process), the washing liquid purified by the membrane filter Transferred to a washing tank to reuse part, and the other is made so that the remaining hoeryu mixed with the oil filtrate was removed (hoeryu step), after the predetermined time has passed since the hoeryu The filtrate was transferred to a step of cutting oil concentrate tank.

The ozone sterilization process is a process of preventing various microorganisms such as non-aqueous oil (heterogeneous oil), microchips, bacteria and gom palms from seriously contaminating the membrane filter during normal temperature operation, and ensuring a stable amount of permeate through the membrane filter. to be. Therefore, the ozone sterilization process is preferably performed in the membrane filter preprocess, and in particular, ozone is injected into the washing tank and / or the oil / water separation tank to prevent contamination of the washing tank and the occurrence of odor and reduction of the concentration of the cleaning agent.

In the particle removal process, the metal soap in a state in which it is combined with the metal particles is also precipitated and removed together with the metal particles, and a relatively large particle oil floats to the surface of the tank.

According to Darcy's law, when heterogeneous mixed liquid passes through the filling layer filled with the porous filler, the flow rate of each liquid component is proportional to the pressure difference applied to the liquid, and the proportional constant is the permeation coefficient. Accordingly, the liquid that has undergone the pretreatment filtration is introduced into and passed through the top of the filling portion of the poly or polypropylene-polled or terraret filled tank, which is an oil removal process, and is combined with floating oil, physically emulsified oil, and floating oil. The velocity gradient occurs due to the difference in permeation coefficient between the water and the metal soap, and the oil particles coalesce to the top of the tank. The injured oil is removed by a separate device such as a weir.

The flow of the flow from the membrane filter to the concentrate mixture process is about 30 to 40 times the capacity of the system, so when it is directly returned to the pretreatment filtration process or the oil / water separation process, the flow rate in the process is drastically increased. Since the residence time is reduced to increase, it is to prevent the reduction of removal efficiency of fine metal particles, physically emulsified oil, metal soap and the like.

In the concentrate mixing process, a process of removing impurities after a predetermined time and transferring the emulsion-type oil flowing from the membrane filter to the cutting oil concentration tank is added.

Since the washing liquid having a lower pH value (reduced to neutral) is circulated to the washing tank, it is necessary to measure the pH value of the washing liquid flowing from the membrane filter to maintain a constant pH concentration in the washing tank. Therefore, the flow control process measures the pH value of the washing liquid purified by the membrane filter, converts the pH value of the measured washing liquid into an electrical signal, and then controls the input of the electrical signal as a control signal of the detergent input control valve. It is preferable to include a signal input process.

On the other hand, the membrane filter requires a regular cleaning process because the filtering effect is reduced if used for a certain period. Typically, the membrane filter deteriorates 25-35% of the filtering function every month, and in order to recover the 25-35% of the filtering function, the concentrate mixture process, the recirculation process, and the like are stopped. To clean the membrane filter.

In order to realize the method of reusing the cutting oil and the washing liquid by the ozone injection, the present invention is provided with an ozone injection device in which ozone can be sterilized and ozone flow paths are formed to allow ozone to flow. It is possible to fill the washing liquid, and the detergent storage tank is provided with a detergent discharge port for discharging the detergent, connected to the ozone pipe line of the ozone injection device and the discharge passage of the detergent reservoir, the washing liquid and oil is filled and the washing liquid and oil A washing tank having one end opened to be discharged to the outside, a pretreatment filter formed to discharge the washing liquid and oil of the washing tank, and removing the fine metal chips of the washing liquid and oil, and connected to the ozone pipe line of the ozone injection device. The washing liquid and oil filtered in the pretreatment filter are introduced and 10-20 to the flowing washing liquid and oil. An oil and water tank for coal oil removal inside and outside the micron to remove the oil, a concentration tank through which the filtrate and the micelle-type oil are mixed to form a mixed solution, and a mixed solution of the concentration tank flows in, and the detergent of the mixed solution flows in. The micropores are formed to remove only the various processed oils and particles that have been emulsified while the components are maintained in the aqueous washing solution, and a flow tube is formed such that the various emulsified process oils and particles are returned to the concentration tank, and the aqueous washing liquid is discharged to the washing tank. A membrane filter in which a discharge pipe is formed; It provides a cleaning liquid recycling apparatus comprising a.

The oil and water separation tank, when there is a lot of oil, such as floating oil, physically emulsified oil generated in the cleaning process, waste water-soluble oil treatment process, etc. after the heat treatment, and forms the inner partition to be 2/3 and 1/3 by volume basis , 2/3, remove the floating oil or physically emulsified oil contained in the inflowing untreated wastewater or water-soluble washing liquid, and recycle to the washing tank. After removing the floating oil or the physically emulsified oil contained in the untreated wastewater or the aqueous washing solution, it may be allowed to flow out into the concentration tank.

The concentrating tank preferably adds a cutting oil concentrating tank for removing impurities, transferring and storing the cutting oil circulated from the membrane filter after a predetermined time has elapsed.

It is preferable to equip each device of the ozone injection device, the detergent storage tank, the cleaning tank, the pretreatment filter, the oil / water separation tank, and the concentration tank with a discharge pump and an electronic flowmeter. Detailed monitoring is possible.

In addition, the present invention is provided between the membrane filter and the washing tank and a pH meter for measuring the pH value of the washing liquid, a controller for receiving the pH value of the pH meter and generating an electrical signal by the pH value; In addition, the washing liquid input control valve is mounted to the outlet of the detergent reservoir and receives the electrical signal of the controller and the valve is controlled by the control signal.

The pH meter, the controller, the washing liquid input control valve, when the pH concentration of the washing liquid discharged from the membrane filter is diluted (falling to neutral), the washing effect of the circulated washing liquid is inferior to generate an electrical signal by the pH value Open and close the cleaning agent input control valve and add the cleaning solution to maintain the pH level of the cleaning tank properly.

Hereinafter, with reference to the accompanying drawings will be described a specific process of the present invention.

1 illustrates a process for reusing cutting oil and washing liquid by ozone injection according to the present invention, and FIG. 2 illustrates a sequence of the process.

The method of reusing the washing liquid by ozone injection according to the present invention prevents contamination of the washing tank 12 caused by the generation of microorganisms such as bacteria and fungi, odor generation, and dilution of the detergent concentration, and contaminates the membrane filter 16. In order to prevent that, ozone is injected into the washing tank 12 and / or the oil / water separation tank 14. The ozone is injected from the ozone injection device 11, it is adjusted according to the unit time, the degree of contamination of the washing tank (S11).

Then, the ozone injected into the washing tank 12 and the washing liquid and oil are mixed and sterilized (S12), and the micrometal chip within 20 microns is removed through the pretreatment filter (S13). The washing liquid and oil in which the fine metal chips within 20 microns are removed are coalesced with oil particles of about 10-20 microns in the oil / water separation tank 14 to float upwards, and the oil is removed and discharged to the concentration tank (S14).

The filtrate from which oil is removed in the oil / water separation tank 14 is mixed with micelle-type oil which has not passed through the membrane filter (S15) and discharged to the membrane filter 16 again. The filtrate discharged to the membrane filter 16 is converted into a purified washing liquid is transferred to the washing tank 12 so that a part is reused, and the rest is returned to the concentration tank 15 (S16).

In addition, in the process transferred from the membrane filter 16 to the washing tank 12, a pH meter 18 is mounted between the membrane filter and the washing tank 12 to measure the pH concentration of the washing liquid purified from the membrane filter 16 ( S18), according to the pH concentration of the purified washing liquid inputs an electrical signal to the washing liquid inlet control valve 20 mounted on the cleaning agent outlet of the detergent reservoir 17 to adjust the cleaning agent input.

The remainder which is circulated to the concentration tank is an emulsion oil and cutting oil. The cutting oil is stored so that after a predetermined time in the concentrating tank 15, impurities are removed and transferred to the cutting oil concentrating tank 19 to be reused (S17).

The washing liquid input control valve 20 may be controlled by a controller having a specific algorithm, and the specific algorithm may apply PID, PI, and Fuzzy algorithms according to the washing liquid input precision or the washing liquid input reaction time. (Not shown).

In addition, the controller may be a PLC, a DSP, and a microcontroller, which is conventionally implemented in hardware.

On the other hand, reference numeral 22 denotes a chemical cleaning bath for cleaning the membrane filter, and is a device generally required in a process using the membrane filter. When the cleaning process of the membrane filter is simplified, the concentrated liquid mixing process and the valves such as the circulating process are blocked in the present process to stop the concentrated liquid mixing process, the circulating process, and the chemical cleaning tank 22 in which the predetermined chemicals are mixed. After connecting only the membrane filter 16, the chemical mixture of the chemical cleaning tank is passed through the membrane filter 16 for a predetermined time. Since the cleaning process of the membrane filter is a process that can be easily performed by those skilled in the art using the membrane filter, a detailed description thereof will be omitted.

Unexplained reference numerals 25, 26, 27, 28, and 29 of the present specification are commonly used in general control processes as inflow pumps, circulation pumps, flow meters, industrial water, cleaning agents, preservatives, and air supplies, and those of ordinary skill in the art Any device can be easily recognized, so additional description thereof will be omitted herein.

What has been described above is just one embodiment for implementing the cutting oil and washing liquid reuse method and apparatus by ozone injection according to the present invention, the present invention is not limited to the above-described embodiment, in the claims below As claimed, any person having ordinary skill in the art without departing from the gist of the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

As described above, the method and apparatus for reusing cutting oil and washing liquid by ozone injection according to the present invention provide bacteria and mold by providing ozone injection process to prevent contamination of washing tank caused by microbial generation and odor generation and reduction of detergent concentration. Eliminate the inconvenience of periodically cleaning the membrane filter contaminated with bacteria, such as using a non-contaminated membrane filter can ensure a stable amount of permeate. In addition, the present invention provides a control signal input process for measuring the pH of the washing liquid discharged from the membrane filter, converting the measured pH value into an electrical signal and inputting it as a control signal of the cleaning agent inlet control valve to efficiently input the cleaning agent. It can be improved, and the pH concentration of the washing tank can be adjusted constantly. In addition, the present invention can additionally obtain a cutting oil savings effect by separating the used cutting oil from the membrane filter by washing with the washing liquid, removing the residue of the cutting oil, and reusing the cutting oil.

1 is a simplified view showing a washing solution reuse process using ozone injection according to the present invention,

2 is a flow chart showing a washing solution reuse process using ozone injection according to the present invention,

3 is a schematic process diagram for reuse of a water-soluble detergent according to a conventional embodiment,

4 is a schematic process chart for reuse of a water-soluble detergent according to another conventional embodiment.

[Description of main part of drawing]

11 ... ozone injection unit 12 ... cleaning tank

13 ... pretreatment filter 14 ... oil / water separator

15 ... thickener 16 ... membrane filter

17 ... cleaning fluid reservoir 18 ... pH meter

19 ... Coolant concentration tank 20 ... Cleaning fluid input control valve

21 ... cleaner transfer pump 22 ... chemical cleaning tank

23 ... inlet pump 24 ... circulation pump

25 ... flow meter 26 ... industrial water

27 ... cleaning agents 28 ... preservatives

29 ... air supply

Claims (5)

In the method of recovering / recovering the contaminated cutting oil and washing liquid used in the washing process, An ozone sterilization process for sterilizing bacteria contained in the washing solution and oil by injecting ozone into the washing tank and / or oil / water separation tank containing the washing solution and oil in a contaminated state; A particle removal step of removing the fine metal chip within 20 microns by passing the washing solution and oil sterilized in the ozone sterilization process through a pretreatment filter; The oil removal process of removing the oil by incorporating the oil particles of about 10-20 microns in the oil-water separation tank filled with media with the large particle washing solution and oil not removed in the particle removal step to rise to the top, A concentrate mixture process in which a micelle-type oil which does not penetrate the filtrate and the membrane filter that have passed through the oil / water separation process is mixed, and the mixed solution of the filtrate and the oil is discharged to the membrane filter; A circulating process of transferring a part of the washing solution purified by the membrane filter to a washing tank and recycling the rest to the concentrate mixing process, and then transferring the washing liquid to a concentrated concentration of cutting oil after a predetermined time; Cutting oil and washing solution reuse method by ozone injection comprising a. The method of claim 1, The reflow process includes a control signal input process of measuring the pH of the washing solution purified by the membrane filter, converting the pH value of the washing solution into an electrical signal, and inputting it as a control signal of the cleaning agent input control valve. Method for reusing cutting oil and washing liquid by ozone injection. In the apparatus for recovering / regenerating the contaminated washing liquid used in the washing process, An ozone injection device that generates ozone to sterilize bacteria and has an ozone pipe through which ozone can flow; A detergent storage tank filled with a detergent capable of washing metal parts, and having a detergent discharge port through which the detergent is discharged; A washing tank connected to the ozone pipe line of the ozone injection device and the discharge path of the cleaning agent storage tank and having one end opened to fill the cleaning liquid and oil and to discharge the cleaning liquid and oil to the outside; A pretreatment filter formed to discharge the washing liquid and oil of the washing tank and to remove fine metal needles of the washing liquid and oil, An oil and water separation tank connected to the ozone pipe line of the ozone injection device, into which the washing solution and oil filtered in the pretreatment filter are introduced, and incorporating oil particles of about 10-20 microns into the introduced washing solution and oil to remove the oil. A condensation tank which mixes the filtrate and the micelle-type oil which have passed through the oil / water separation tank to produce a mixed solution, A cutting oil concentrating tank for storing the cutting oil refined in the concentrating tank for reuse; The mixed solution of the concentration tank is introduced, and the microcavity is formed to remove only the various processed oils and particles emulsified while the detergent component of the mixed liquid is maintained in the aqueous washing liquid, and a flow tube is formed so that the various emulsified processed oils and particles are returned to the concentration tank. A membrane filter having a discharge pipe formed to discharge the water-soluble washing liquid into the washing tank; Apparatus for reusing cutting oil and washing liquid by ozone injection comprising a. The method of claim 3, wherein A pH meter mounted between the membrane filter and the washing tank and capable of measuring the pH value of the washing liquid, a controller for receiving the pH value of the pH meter and generating an electrical signal based on the pH value, and an outlet of the washing tank. Apparatus for reuse of cutting oil and cleaning liquid by ozone injection, characterized in that it comprises a washing liquid input control valve mounted to and receiving the electrical signal of the controller and the valve is controlled by the control signal. delete