WO1997017294A1 - Apparatus for separating oil from waste water containing oil emulsion and method therefor - Google Patents
Apparatus for separating oil from waste water containing oil emulsion and method therefor Download PDFInfo
- Publication number
- WO1997017294A1 WO1997017294A1 PCT/KR1996/000193 KR9600193W WO9717294A1 WO 1997017294 A1 WO1997017294 A1 WO 1997017294A1 KR 9600193 W KR9600193 W KR 9600193W WO 9717294 A1 WO9717294 A1 WO 9717294A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- waste water
- oil
- reservoir
- tank
- water
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
- B01D17/02—Separation of non-miscible liquids
- B01D17/0208—Separation of non-miscible liquids by sedimentation
- B01D17/0214—Separation of non-miscible liquids by sedimentation with removal of one of the phases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
- B01D17/02—Separation of non-miscible liquids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
- B01D17/02—Separation of non-miscible liquids
- B01D17/0208—Separation of non-miscible liquids by sedimentation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
- B01D17/02—Separation of non-miscible liquids
- B01D17/04—Breaking emulsions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
- B01D17/06—Separation of liquids from each other by electricity
Definitions
- the present invention concerns waste water treatment, and more particularly an apparatus for separating oil (normal hexane) from the waste water containing oil emulsion which is produced from various machining processes like milling, rolling, cutting, etc. using a lubricant such as a cutting oil.
- the cutting oil consists of an oil emulsified in water generally, where the oil exists in the form of fine droplets with a diameter less than l ⁇ m.
- the lubricant used for smoothing the machining processes such as cutting, milling, rolling, etc. consists of an oil dispersed in water in fine droplets of larger than colloidal size.
- oil emulsion such lubricant is referred to as oil emulsion.
- the oil droplets dispersed in the oil emulsion are not normally separated from the water even when the oil emulsion is kept undisturbed for a long time because their gravities, Van der Waals forces and repulsion are in equilibrium. Furthermore, the oil droplets are negatively charged, repelling one another and uniformly dispersed in the water, so that their surfaces are gradually activated to form chemical bonds with water molecules, thus establishing static equilibrium.
- the emulsion oil used in machining processes such as cutting or rolling is usually impossible to recycle, and moreover results in a serious environmental pollution if discharged as is.
- the emulsion break treatment includes adding a multivalent metallic salt or organic chemical to the oil emulsion, heating of the oil emulsion, etc.
- the method of treating the oil emulsion by adding a multivalent metallic salt is to treat an oil emulsion with an oil droplet size of less than l ⁇ m, characterized by making a coprecipitation of the emulsion by means of Al or Fe floe.
- the method relating to the addition of an organic chemical is to destroy the oil emulsion by using an activation agent oppositely charged.
- the method of treating the oil emulsion by heating is to destroy by adjusting the PH towards alkali and heating over 70°C.
- the first method results in the generation of large amount of sludge causing the problems of dealing with the floe, the second with the problems of relating to the cost and toxicity of the activation agent (of cation series), and the heating method is to treat a small volume of a highly concentrated waste water with the problems resulting from the use of excessive energy.
- the electrolysis treatment is to treat an oil emulsion with an oil droplet size of less than l ⁇ m, characterized by using soluble Al electrodes to deal with waste water less than 10,000mg/l.
- This method has such drawbacks as generation of relatively small floe, discoloration, and limitation of the space between electrodes so as to make it difficult to build the treatment system on a large scale.
- the biological treatment employs active sludge causing gas bubbles, which suffers such drawbacks as addition of nutrient salt, generation of a large amount of sludge, and a long time for processing the waste water containing oil emulsion. Furthermore, this method is to treat organic waste water including animal and plant oil, and the mineral oil is removed by being combined with microorganisms having affinity to oil.
- the concentrated burning method is to burn waste water concentration containing less than 75% water in a combustion furnace, which suffers such drawbacks as generation of sealer trouble and requisition of a supplementary fuel oil. Therefore, the conventional methods described above not only have unresolved inherent problems, but also incomplete to perform effective treatment of the waste water containing oil emulsion. In this context, it will be very ideal if there be a chemical method using an adso ⁇ tive agent to adsorb oil droplets in waste water or a physical method only using mechanical forces to separate oil from waste water.
- an apparatus for separating oil from waste water containing oil emulsion which comprises a waste water reservoir for holding said waste water containing oil emulsion, waste water treating arrangement for treating for a given time the waste water supplied from the waste water reservoir through a supply pump and pipe by a given amount, oil float waiting reservoir for holding the treated water delivered from the waste water treating arrangement for a given time so as to make the oil part in the treated water float separated from the water part falling down by the force of gravity to the bottom, oil collecting reservoir for collecting the separated floating oil in the oil float waiting reservoir by means of an oil sucker means, chemical reactor tank for holding and urifying the separated water delivered from the oil float waiting reservoir, and chemical tank with an agitator for supplying a purifying chemical agent to the separated water held in the chemical reactor tank, wherein the waste water treating arrangement includes a catalyst supply means, normal-hexane treatment tank, and circulation piping provided with a magnetofluiddynamic device.
- the magnetofluiddynamic device is to destroy
- a method for separating oil from waste water containing oil emulsion comprising the steps of supplying a given amount of the waste water containing oil emulsion held in a waste water reservoir to a waste water treating tank by means of a supply pump, injecting a given amount of a catalyst into the waste water held in the waste water treating tank to enhance its electrical conductivity, circulating the waste water with enhanced electrical conductivity through a circulation piping provided with a magnetofluiddynamic device to magnetize it by working a circulation pump for a given time, the circulation piping mounted on the side wall of the waste water treating tank, delivering the circulated waste water through a discharge piping to an oil float waiting reservoir to hold it still for a given time so as to make the oil part in the circulated waste water float separated from the water part falling down by the force of gravity to the bottom, delivering the water part separated from the oil part in the preceding step through an outlet formed in the bottom of the oil float waiting reservoir to a chemical reactor tank by means of
- Fig. 1 is a schematic block diagram for illustrating an apparatus for treating the waste water containing oil emulsion according to the present invention
- Fig. 2 is a block diagram for illustrating a circulation piping provided with a magnetofluiddynamic device to produce a magnetic field for contributing to the separation of the oil and water in the waste water;
- Fig. 3A is a perspective view for illustrating the magnetofluiddynamic device according to the present invention.
- Fig. 3B is a cross sectional view of Fig. 3A;
- Fig. 4 is a graph for illustrating the rate of oil removal with the treating time and the electrical conductivity of the waste water during the treatment by employing the apparatus of Fig. 1 ;
- Fig. 5 is a graph for illustrating the rate of oil removal with the electrical conductivity of the waste water during the treatment by employing the apparatus of Fig. 1 ;
- Fig. 6 is a graph for illustrating the rate of oil removal with the time and speed of the waste water circulating in the circulation piping during the treatment by employing the apparatus of Fig. 1 ;
- Fig. 7 is a graph for illustrating the rate of oil removal with the speed of the waste water circulating in the circulation piping during the treatment by employing the apparatus of Fig. 1 ;
- Fig. 8 is a graph for illustrating the relationship between the treatment time and PH of the waste water during the treatment by employing the apparatus of Fig. 1.
- the inventive apparatus 1 for separating oil from waste water containing oil emulsion includes a waste water reservoir 2 for holding the wa ⁇ te water containing oil emulsion, waste water treating arrangement 20 for treating for a given time the waste water supplied from the waste water reservoir 2 through a supply pump 8 and pipe by a given amount oil float waiting reservoir 13, oil collecting reservoir 12, chemical reactor tank 4, and chemical tank 18.
- the oil float waiting reservoir 13 is to hold the treated water delivered from the waste water treating arrangement 20 for a given time so as to make the oil part in the treated water float separated from the water part falling down by the force of gravity to the bottom.
- the oil collecting reservoir 12 is to collect the separated floating oil in the oil float waiting reservoir 13 by means of an oil sucker device 17.
- the chemical reactor tank is to hold and purify the separated water delivered from the oil float waiting reservoir 13.
- the chemical tank 18 is provided with an agitator, and supplies a purifying chemical agent to the separated water held in the chemical reactor tank 4.
- the waste water treating arrangement includes a treatment tank 3 for holding the waste water to treat, catalyst supply device 16 for supplying a catalyst to the waste water in the treatment tank 3 to enhance the electrical conductivity of the waste water, and circulation piping 6 provided with a magnetofluiddynamic device 5 and circulation pump 9 to circulate the waste water with enhanced electrical conductivity in order to destroy the stability of the oil droplets dispersed in the waste water.
- the waste water is firstly collected into the waste water reservoir 2, and then the supply pump 8 is worked to deliver the collected waste water to the treatment tank 3 of the waste water treating arrangement 20.
- a catalyst is added to the waste water in the treatment tank 3 by a suitable amount to enhance the electrical conductivity of the waste water. NaCl may be used for the catalyst.
- the waste water is circulated through the circulation piping 6 by working the circulation pump 9 for a given time, which circulation piping is mounted on the side wall of the treatment tank and equipped with the magnetofluiddynamic device 5 for magnetizing the circulating waste water.
- the waste water is delivered through a discharge pipe to the oil float waiting reservoir 13, where the oil part floats up separated from the water part falling down to the bottom by gravity, for the magnetization ofthe waste water serves to destroy the stability of the oil droplets increasing the coalescing forces between them.
- the water part separated from the oil part is transferred through an outlet provided in the bottom of the oil float waiting reservoir 13 to the chemical reactor tank 4 or ozonization tank by working a transfer pump while the floating oil part is transferred to the oil collecting reservoir 12 by means of the oil sucker 17.
- the magnetized water collected in the chemical reactor tank 4 is supplied with a purification agent from the chemical tank 18 agitated by working the agitator 15 for a given time, or ozonized in an ozonization tank finally discharged out as a purified water through an outlet formed in the bottom of the tank.
- the circulation piping 6 is provided with the magnetofluiddynamic device 5 for magnetizing the emulsified oil droplets to destroy the stability so as to increase the coalescing forces between them, forming a circulation loop from the bottom of the waste water treating arrangement 20 through the circulation pump 9 to the magnetofluiddynamic device 5 to the treatment tank 3.
- the circulation pump 9 is made to regulate the circulation speed of the waste water flowing through the circulation piping 6, which may be measured by a flow meter 10 provided between the circulation pump and the magnetofluiddynamic device 5.
- the magnetofluiddynamic device 5 for magnetizing the waste water comprises at least two bar magnets 7 fixedly arranged in a tube of the same diametral dimension as the circulation piping with a space between them and their polarities being opposite one another as shown Figs. 3A and 3B.
- the number of the bar magnets 7 may be increased, or a plurality of the magnetofluiddynamic devices 5 as shown in Fig. 3A cascaded.
- the emulsified oil droplets of the waste water are magnetically polarized increasing the zeta potential, so that the physical and chemical properties of the waste water such as surface tension, PH, etc. are changed.
- the increased zeta potential and Lorentz electric field serve to compress the electrical double layer existing at the interface of the emulsified oil droplets so as to effectively destroy them, thus increasing their coalescing forces to result in the separation of the oil and water.
- a waste cutting oil (about 18,000ppm N-Hexane) of about 2 ton is supplied with NaCl for a catalyst to increase the electrical conductivity.
- a specimen of 250L is circulated through the circulation piping 6 equipped with the magnetofluiddynamic device 5, transferred to the oil float waiting reservoir 13, where the waste water containing oil emulsion is held for a given time so as to make the oil droplets coalesce and float above the water part falling down separated to the bottom by gravity.
- the factors to affect the treatment such as the flow rate, electrical conductivity, PH, etc. of the waste water are varied to determine the operational environment for achieving the optimum result.
- the different rates of the oil removal obtained by varying the factors are quantitatively compared and analyzed.
- Fig. 4 The results obtained by varying the electrical conductivity of the specimen with a fixed flow rate of 3 m/sec through the magnetofluiddynamic device 5 are shown in Fig. 4, from which it is noted that the removal rate of the emulsified oil increases with the electrical conductivity. Of course, it increases with time at same electrical conductivity.
- the electrical conductivity may be adjusted by the amount of a catalyst supplied from the catalyst supply device 16, for which NaCl is used in the experiment.
- Fig. 5 shows the removal rate of the emulsified oil with varied electrical conductivities for a fixed treating time of 60 minutes.
- the straight line means the removal rate in proportion to the strength of the electric field.
- Fig. 8 shows the measurements of the PH of the specimen circulating through the magnetofluiddynamic device 5, which vary with time at a fixed electrical conductivity of 8mV/cm and fixed flow rate of about 8m/sec.
- the oil and water part of the waste water containing oil emulsion may be effectively separated by employing the circulation piping equipped with the inventive magnetofluiddynamic device generating Lorentz electric field. whereby it is possible to reduce the pollution degree of an oil emulsion of about 18,000 ppm to less than 150 ppm.
- the present invention provides a physical treatment of the waste water containing oil emulsion without employing the conventional chemical or biological process, so that the effectiveness of the waste water treatment is considerably increased together with reduction ofthe cost.
Abstract
An apparatus for separating oil from waste water containing oil emulsion includes a waste water reservoir for holding the waste water containing oil emulsion, waste water treating arrangement for treating the waste water supplied fron the waste water reservoir, oil float waiting reservoir, oil collecting reservoir, chemical reactor tank, and chemical tank. The oil float waiting reservoir is to hold the treated water delivered from the waste water treating arrangement for a given time so as to make the oil part in the treated water float separated from the water part falling down by the force of gravity to the bottom. The waste water treating arrangement includes a treatment tank for holding the waste water to treat, catalyst supply device for supplying a catalyst to the waste water in the treatment tank to enhance the electrical conductivity of the waste water, and circulation piping provided with a magnetofluiddynamic device and circulation pump to circulate the waste water with enhanced electrical conductivity in order to destroy the stability of the oil droplets dispersed in the waste water.
Description
DESCRIPTION
APPARATUS FOR SEPARATING OIL FROM WASTE WATER CONTAINING OIL EMULSION AND METHOD THEREFOR
Technical Field
The present invention concerns waste water treatment, and more particularly an apparatus for separating oil (normal hexane) from the waste water containing oil emulsion which is produced from various machining processes like milling, rolling, cutting, etc. using a lubricant such as a cutting oil. The cutting oil consists of an oil emulsified in water generally, where the oil exists in the form of fine droplets with a diameter less than lμm.
Background Art
Generally, the lubricant used for smoothing the machining processes such as cutting, milling, rolling, etc. consists of an oil dispersed in water in fine droplets of larger than colloidal size. Hereinafter, such lubricant is referred to as oil emulsion. The oil droplets dispersed in the oil emulsion are not normally separated from the water even when the oil emulsion is kept undisturbed for a long time because their gravities, Van der Waals forces and repulsion are in equilibrium. Furthermore, the oil droplets are negatively charged, repelling one another and uniformly dispersed in the water, so
that their surfaces are gradually activated to form chemical bonds with water molecules, thus establishing static equilibrium. Hence the emulsion oil used in machining processes such as cutting or rolling is usually impossible to recycle, and moreover results in a serious environmental pollution if discharged as is.
In order to prevent such environmental pollution caused by the oil emulsion, there have been proposed various methods of treating the oil emulsion including the emulsion break treatment, electrolysis treatment, biological treatment, concentrated burning, etc, which all are directed to separate the oil and water. Among these, the emulsion break treatment includes adding a multivalent metallic salt or organic chemical to the oil emulsion, heating of the oil emulsion, etc. The method of treating the oil emulsion by adding a multivalent metallic salt is to treat an oil emulsion with an oil droplet size of less than lμm, characterized by making a coprecipitation of the emulsion by means of Al or Fe floe. The method relating to the addition of an organic chemical is to destroy the oil emulsion by using an activation agent oppositely charged. The method of treating the oil emulsion by heating is to destroy by adjusting the PH towards alkali and heating over 70°C. The first method results in the generation of large amount of sludge causing the problems of dealing with the floe, the second with the problems of relating to the cost and toxicity of the activation agent (of cation series), and the heating method is to treat a small volume of a highly concentrated waste water with the problems resulting from the use of excessive energy.
The electrolysis treatment is to treat an oil emulsion with an oil droplet size of less than lμm, characterized by using soluble Al electrodes to deal with waste water less than 10,000mg/l. This method has such drawbacks as generation of relatively small floe, discoloration, and limitation of the space between electrodes so as to make it difficult to build the treatment system on a large scale.
The biological treatment employs active sludge causing gas bubbles, which suffers such drawbacks as addition of nutrient salt, generation of a large amount of sludge, and a long time for processing the waste water containing oil emulsion. Furthermore, this method is to treat organic waste water including animal and plant oil, and the mineral oil is removed by being combined with microorganisms having affinity to oil.
The concentrated burning method is to burn waste water concentration containing less than 75% water in a combustion furnace, which suffers such drawbacks as generation of sealer trouble and requisition of a supplementary fuel oil. Therefore, the conventional methods described above not only have unresolved inherent problems, but also incomplete to perform effective treatment of the waste water containing oil emulsion. In this context, it will be very ideal if there be a chemical method using an adsoφtive agent to adsorb oil droplets in waste water or a physical method only using mechanical forces to separate oil from
waste water.
Disclosure of the Invention
It is an object of the present invention to provide a physical method of treating waste water containing oil emulsion, which enhances the electrical conductivity of the waste water to produce a magnetic field therein so as to destroy the stability of the emulsified oil droplets and thus increase their coalescing forces for separating the oil and water.
According to an embodiment of the present invention, there is provided an apparatus for separating oil from waste water containing oil emulsion, which comprises a waste water reservoir for holding said waste water containing oil emulsion, waste water treating arrangement for treating for a given time the waste water supplied from the waste water reservoir through a supply pump and pipe by a given amount, oil float waiting reservoir for holding the treated water delivered from the waste water treating arrangement for a given time so as to make the oil part in the treated water float separated from the water part falling down by the force of gravity to the bottom, oil collecting reservoir for collecting the separated floating oil in the oil float waiting reservoir by means of an oil sucker means, chemical reactor tank for holding and urifying the separated water delivered from the oil float waiting reservoir, and chemical tank with an agitator for supplying a purifying chemical agent to the separated water
held in the chemical reactor tank, wherein the waste water treating arrangement includes a catalyst supply means, normal-hexane treatment tank, and circulation piping provided with a magnetofluiddynamic device. The magnetofluiddynamic device is to destroy the stability of the oil droplets dispersed in the waste water.
According to another embodiment of the present invention, a method for separating oil from waste water containing oil emulsion, comprising the steps of supplying a given amount of the waste water containing oil emulsion held in a waste water reservoir to a waste water treating tank by means of a supply pump, injecting a given amount of a catalyst into the waste water held in the waste water treating tank to enhance its electrical conductivity, circulating the waste water with enhanced electrical conductivity through a circulation piping provided with a magnetofluiddynamic device to magnetize it by working a circulation pump for a given time, the circulation piping mounted on the side wall of the waste water treating tank, delivering the circulated waste water through a discharge piping to an oil float waiting reservoir to hold it still for a given time so as to make the oil part in the circulated waste water float separated from the water part falling down by the force of gravity to the bottom, delivering the water part separated from the oil part in the preceding step through an outlet formed in the bottom of the oil float waiting reservoir to a chemical reactor tank by means of a delivery pump and the floating oil part through an oil sucker means to a normal-hexane collecting reservoir, supplying a purifying chemical agent from a chemical tank
with an agitator to the magnetized water held in the chemical reactor tank, and stirring the magnetized water containing the purifying chemical agent with an agitator mounted on the chemical reactor tank to produce a purified water.
The present invention will now be described more specifically with reference to the drawings attached only by of example.
Bief Description of Drawing
Fig. 1 is a schematic block diagram for illustrating an apparatus for treating the waste water containing oil emulsion according to the present invention;
Fig. 2 is a block diagram for illustrating a circulation piping provided with a magnetofluiddynamic device to produce a magnetic field for contributing to the separation of the oil and water in the waste water;
Fig. 3A is a perspective view for illustrating the magnetofluiddynamic device according to the present invention;
Fig. 3B is a cross sectional view of Fig. 3A;
Fig. 4 is a graph for illustrating the rate of oil removal with the treating time and the electrical conductivity of the waste water during the treatment by employing the apparatus of Fig. 1 ;
Fig. 5 is a graph for illustrating the rate of oil removal with the electrical conductivity of the waste water during the treatment by
employing the apparatus of Fig. 1 ;
Fig. 6 is a graph for illustrating the rate of oil removal with the time and speed of the waste water circulating in the circulation piping during the treatment by employing the apparatus of Fig. 1 ;
Fig. 7 is a graph for illustrating the rate of oil removal with the speed of the waste water circulating in the circulation piping during the treatment by employing the apparatus of Fig. 1 ; and
Fig. 8 is a graph for illustrating the relationship between the treatment time and PH of the waste water during the treatment by employing the apparatus of Fig. 1.
Best Mode for Carring out the Invention
Referring to Fig. 1 , the inventive apparatus 1 for separating oil from waste water containing oil emulsion, includes a waste water reservoir 2 for holding the wa^te water containing oil emulsion, waste water treating arrangement 20 for treating for a given time the waste water supplied from the waste water reservoir 2 through a supply pump 8 and pipe by a given amount oil float waiting reservoir 13, oil collecting reservoir 12, chemical reactor tank 4, and chemical tank 18. The oil float waiting reservoir 13 is to hold the treated water delivered from the waste water treating arrangement 20 for a given time so as to make the oil part in the treated water float separated from the water part falling down by the force of gravity to the bottom. The oil collecting reservoir 12 is to collect the separated floating oil in the oil float waiting reservoir 13 by means of an oil sucker device 17. The
chemical reactor tank is to hold and purify the separated water delivered from the oil float waiting reservoir 13. The chemical tank 18 is provided with an agitator, and supplies a purifying chemical agent to the separated water held in the chemical reactor tank 4. In stead of the chemical reactor tank 4, there may be provided an ozonization tank.
The waste water treating arrangement includes a treatment tank 3 for holding the waste water to treat, catalyst supply device 16 for supplying a catalyst to the waste water in the treatment tank 3 to enhance the electrical conductivity of the waste water, and circulation piping 6 provided with a magnetofluiddynamic device 5 and circulation pump 9 to circulate the waste water with enhanced electrical conductivity in order to destroy the stability of the oil droplets dispersed in the waste water.
Describing the steps of treating of waste water containing oil emulsion, the waste water is firstly collected into the waste water reservoir 2, and then the supply pump 8 is worked to deliver the collected waste water to the treatment tank 3 of the waste water treating arrangement 20. A catalyst is added to the waste water in the treatment tank 3 by a suitable amount to enhance the electrical conductivity of the waste water. NaCl may be used for the catalyst. The waste water is circulated through the circulation piping 6 by working the circulation pump 9 for a given time, which circulation piping is mounted on the side wall of the treatment tank and equipped
with the magnetofluiddynamic device 5 for magnetizing the circulating waste water. Finishing the circulation, the waste water is delivered through a discharge pipe to the oil float waiting reservoir 13, where the oil part floats up separated from the water part falling down to the bottom by gravity, for the magnetization ofthe waste water serves to destroy the stability of the oil droplets increasing the coalescing forces between them.
The water part separated from the oil part is transferred through an outlet provided in the bottom of the oil float waiting reservoir 13 to the chemical reactor tank 4 or ozonization tank by working a transfer pump while the floating oil part is transferred to the oil collecting reservoir 12 by means of the oil sucker 17. The magnetized water collected in the chemical reactor tank 4 is supplied with a purification agent from the chemical tank 18 agitated by working the agitator 15 for a given time, or ozonized in an ozonization tank finally discharged out as a purified water through an outlet formed in the bottom of the tank.
Referring to Fig. 2. the circulation piping 6 is provided with the magnetofluiddynamic device 5 for magnetizing the emulsified oil droplets to destroy the stability so as to increase the coalescing forces between them, forming a circulation loop from the bottom of the waste water treating arrangement 20 through the circulation pump 9 to the magnetofluiddynamic device 5 to the treatment tank 3. The circulation pump 9 is made to regulate the circulation speed of the waste
water flowing through the circulation piping 6, which may be measured by a flow meter 10 provided between the circulation pump and the magnetofluiddynamic device 5. The magnetofluiddynamic device 5 for magnetizing the waste water comprises at least two bar magnets 7 fixedly arranged in a tube of the same diametral dimension as the circulation piping with a space between them and their polarities being opposite one another as shown Figs. 3A and 3B. In order to increase the strength of the magnetic field applied to the circulating waste water, the number of the bar magnets 7 may be increased, or a plurality of the magnetofluiddynamic devices 5 as shown in Fig. 3A cascaded.
Circulating through the magnetofluiddynamic device 5, the emulsified oil droplets of the waste water are magnetically polarized increasing the zeta potential, so that the physical and chemical properties of the waste water such as surface tension, PH, etc. are changed. The increased zeta potential and Lorentz electric field serve to compress the electrical double layer existing at the interface of the emulsified oil droplets so as to effectively destroy them, thus increasing their coalescing forces to result in the separation of the oil and water. Hereinafter described is an example to more specifically illustrate the operation of the inventive apparatus.
Employing the inventive apparatus as shown in Fig. 1 , A waste cutting oil (about 18,000ppm N-Hexane) of about 2 ton is supplied with NaCl for a catalyst to increase the electrical conductivity.
A specimen of 250L is circulated through the circulation piping 6 equipped with the magnetofluiddynamic device 5, transferred to the oil float waiting reservoir 13, where the waste water containing oil emulsion is held for a given time so as to make the oil droplets coalesce and float above the water part falling down separated to the bottom by gravity. The factors to affect the treatment such as the flow rate, electrical conductivity, PH, etc. of the waste water are varied to determine the operational environment for achieving the optimum result. The different rates of the oil removal obtained by varying the factors are quantitatively compared and analyzed.
The results obtained by varying the electrical conductivity of the specimen with a fixed flow rate of 3 m/sec through the magnetofluiddynamic device 5 are shown in Fig. 4, from which it is noted that the removal rate of the emulsified oil increases with the electrical conductivity. Of course, it increases with time at same electrical conductivity. The electrical conductivity may be adjusted by the amount of a catalyst supplied from the catalyst supply device 16, for which NaCl is used in the experiment.
Fig. 5 shows the removal rate of the emulsified oil with varied electrical conductivities for a fixed treating time of 60 minutes. The straight line means the removal rate in proportion to the strength of the electric field.
Adding NaCl to the specimen and varying its flow rate
circulating through the magnetofluiddynamic device 5 with a fixed electrical conductivity of 8mV/cm, the removal rate of the oil emulsion is increased with the flow rate as shown in Fig. 6, which means the increase of the Lorentz electric field strength effectively compressing the electrically double layer of the oil emulsion.
Fig. 8 shows the measurements of the PH of the specimen circulating through the magnetofluiddynamic device 5, which vary with time at a fixed electrical conductivity of 8mV/cm and fixed flow rate of about 8m/sec. For the treatment time of 60 minutes, PH is increased from 6.8 to 7.2. It is inferred that this was caused by the increase of OH radical as shown by the formula H20 + l/202 + 2e" = 20H" or 2H20 + 2e'H2 + 20H" and the evaporation of the CO in the specimen due to the rotation of the pump.
As described above, the oil and water part of the waste water containing oil emulsion may be effectively separated by employing the circulation piping equipped with the inventive magnetofluiddynamic device generating Lorentz electric field. whereby it is possible to reduce the pollution degree of an oil emulsion of about 18,000 ppm to less than 150 ppm. In conclusion, the present invention provides a physical treatment of the waste water containing oil emulsion without employing the conventional chemical or biological process, so that the effectiveness of the waste water treatment is considerably increased together with reduction ofthe cost.
Claims
1. An apparatus for separating oil from waste water containing oil emulsion, comprising:
a waste water reservoir for holding said waste water containing oil emulsion;
a waste water treating arrangement for treating for a given time said waste water supplied from said waste water reservoir through a supply pump and pipe by a given amount;
an oil float waiting reservoir for holding the treated water delivered from said waste water treating arrangement for a given time so as to make the oil part in said treated water float separated from the water part falling down by the force of gravity to the bottom;
an oil collecting reservoir for collecting the separated floating oil in said oil float waiting reservoir by means of an oil sucker means;
a chemical reactor tank for holding and purifying the separated water delivered from said oil float waiting reservoir; and
a chemical tank with an agitator for supplying a purifying chemical agent to the separated water held in said chemical reactor tank, wherein said waste water treating arrangement includes a catalyst supply means, normal-hexane treatment tank, and circulation piping provided with a magnetofluiddynamic device.
2. An apparatus for separating oil from waste water containing oil emulsion as defined in Claim 1 , wherein said circulation piping is provided with a plurality of said magnetofluiddynamic device.
3. An apparatus for separating oil from waste water containing oil emulsion as defined in Claim 1 or 2, wherein said magnetofluiddynamic device comprises at least two bar magnets arranged with a space between them and their polarities being opposite one another.
4. An apparatus for separating oil from waste water containing oil emulsion as defined in Claim 1 or 2, wherein said chemical reactor tank is an ozonization tank.
5. A method for separating oil from waste water containing oil emulsion, comprising the steps of:
supplying a given amount of said waste water containing oil emulsion held in a waste water reservoir to a waste water treating tank by means of a supply pump;
injecting a given amount of a catalyst into the waste water held in said waste water treating tank to enhance its electrical conductivity;
circulating the waste water with enhanced electrical conductivity through a circulation piping provided with a magnetofluiddynamic device to magnetize it by working a circulation pump for a given time, said circulation piping mounted on the side wall of said waste water treating tank;
delivering said circulated waste water through a discharge piping to an oil float waiting reservoir to hold it still for a given time so as to make the oil part in said circulated waste water float separated from the water part falling down by the force of gravity to the bottom;
delivering said water part separated from said oil part in the preceding step through an outlet formed in the bottom of said oil float waiting reservoir to a chemical reactor tank by means of a delivery pump and said floating oil part through an oil sucker means to a normal-hexane collecting reservoir;
supplying a purifying chemical agent from a chemical tank with an agitator to the magnetized water held in said chemical reactor tank; and stirring said magnetized water containing said purifying chemical agent with an agitator mounted on said chemical reactor tank to produce a purified water.
6. A method as defined in Claim 5, wherein said catalyst is NaCl.
7. A method as defmed in Claim 5, wherein said water part separated from said oil part in said oil float waiting reservoir is purified in an ozonization tank in stead of said chemical reactor tank.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1995/40005 | 1995-11-04 | ||
| KR19950040005 | 1995-11-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1997017294A1 true WO1997017294A1 (en) | 1997-05-15 |
Family
ID=19433169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/KR1996/000193 WO1997017294A1 (en) | 1995-11-04 | 1996-11-02 | Apparatus for separating oil from waste water containing oil emulsion and method therefor |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR100202997B1 (en) |
| WO (1) | WO1997017294A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106565030A (en) * | 2015-10-12 | 2017-04-19 | 中国石油化工股份有限公司 | Device and method for treating fracturing flowback fluid |
| CN114102235A (en) * | 2021-09-27 | 2022-03-01 | 阿坝铝厂 | Environment-friendly aluminium bar cutting device |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100693029B1 (en) * | 2002-07-11 | 2007-03-12 | 동 석 강 | Apparatus and method for separating oil in the emulsion |
| KR101283005B1 (en) * | 2012-09-04 | 2013-07-09 | 박형중 | Apparatus and method for separating water and oil from lubricant |
| KR101425045B1 (en) | 2013-03-15 | 2014-08-01 | 주식회사 제달 | The water-soluble cutting oil and washing water purifier |
| KR101551327B1 (en) * | 2013-11-12 | 2015-09-18 | 정봉희 | Enhanced purification efficiency wastewater treatment apparatus |
| KR101781187B1 (en) | 2015-04-23 | 2017-09-22 | 주식회사 지에스해양 | Oil outflow purifying apparatus with using magnetism |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2064504A (en) * | 1979-11-28 | 1981-06-17 | Sanderson C H | Device for the magnetic treatment of fluids |
| CA1155086A (en) * | 1981-06-18 | 1983-10-11 | Ross W. Bracewell | Magnetic conditioner and method for conditioning liquids |
| US5466367A (en) * | 1994-04-06 | 1995-11-14 | Environmental Restoration Services, Inc. | Industrial waste water treatment |
-
1996
- 1996-10-22 KR KR1019960047369A patent/KR100202997B1/en not_active IP Right Cessation
- 1996-11-02 WO PCT/KR1996/000193 patent/WO1997017294A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2064504A (en) * | 1979-11-28 | 1981-06-17 | Sanderson C H | Device for the magnetic treatment of fluids |
| CA1155086A (en) * | 1981-06-18 | 1983-10-11 | Ross W. Bracewell | Magnetic conditioner and method for conditioning liquids |
| US5466367A (en) * | 1994-04-06 | 1995-11-14 | Environmental Restoration Services, Inc. | Industrial waste water treatment |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106565030A (en) * | 2015-10-12 | 2017-04-19 | 中国石油化工股份有限公司 | Device and method for treating fracturing flowback fluid |
| CN114102235A (en) * | 2021-09-27 | 2022-03-01 | 阿坝铝厂 | Environment-friendly aluminium bar cutting device |
Also Published As
| Publication number | Publication date |
|---|---|
| KR970025654A (en) | 1997-06-24 |
| KR100202997B1 (en) | 1999-06-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5130032A (en) | Method for treating a liquid medium | |
| Khuntia et al. | Microbubble-aided water and wastewater purification: a review | |
| Mostefa et al. | Coupling flocculation with electroflotation for waste oil/water emulsion treatment. Optimization of the operating conditions | |
| US8845906B2 (en) | Process for single system electrocoagulation, magnetic, cavitation and flocculation (EMC/F) treatment of water and wastewater | |
| US4031006A (en) | Vortex coagulation means and method for wastewater clarification | |
| US7252752B2 (en) | Method and apparatus for removing contaminants from conduits and fluid columns | |
| US4492636A (en) | Process for cleaning metal working fluids for re-use | |
| Mickova | Advanced electrochemical technologies in wastewater treatment. Part II: electro-flocculation and electro-flotation | |
| WO2008018837A2 (en) | Method and apparatus for treating water or wastewater or the like | |
| US20080272056A1 (en) | Method and Apparatus for Separating Impurities from a Liquid Stream by Electrically Generated Gas Bubbles | |
| JP2007061732A (en) | Method for treating waste oil | |
| WO1997017294A1 (en) | Apparatus for separating oil from waste water containing oil emulsion and method therefor | |
| CN102583809A (en) | Silica and oil removing system for oily sewage | |
| CA3092150A1 (en) | System and method for wastewater treatment | |
| Colic et al. | The development and application of centrifugal flotation systems in wastewater treatment | |
| US20150191366A1 (en) | Electro-catalytic process for coalescing and skimming pollutants in bodies of water prior to filtration | |
| JP4337787B2 (en) | Wastewater treatment method and treatment apparatus | |
| CN201971688U (en) | System for removing silicon and oil of oily sewage | |
| Matis et al. | Dissolved—Air and Electrolytic Flotation | |
| CN105016537A (en) | Plug flow type dual-electrode electrolysis air floater | |
| CN114212853B (en) | Air floatation tank for demulsification of emulsified oil-containing wastewater, wastewater treatment system comprising air floatation tank and method | |
| CN108423928A (en) | A kind of processing system of purified industrial waste water | |
| WO2015131111A1 (en) | Electro-catalytic process for coalescing and skimming pollutants in bodies of water prior to filtration | |
| CN211284003U (en) | A compound integrated equipment of electric flocculation dissolved air flotation for waste water preliminary treatment | |
| CN102153252A (en) | Method and system for treating engine ultrasonic cleaning wastewater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): JP US |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
| DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| NENP | Non-entry into the national phase |
Ref country code: JP Ref document number: 97518087 Format of ref document f/p: F |
|
| 122 | Ep: pct application non-entry in european phase |