KR100800528B1 - Dehydrating apparatus unit and method of slurry - Google Patents

Abstract

According to the present invention, the first filter plate having an electrode plate to be charged on one surface; A second filter plate provided at one side of the first filter plate and having a space portion and a diaphragm at one side thereof for receiving the compressed water; A filter cloth positioned between the first filter plate and the second filter plate and having a charge opposite to that of the electrode plate of the first filter plate; A driving unit connected to one side of the filter cloth and driving the filter cloth to move up and down; A filter plate moving part provided at one side of the first filter plate or the second filter plate and moving the first filter plate or the second filter plate from side to side; And a power supply unit connected to the first filtration plate, the filter cloth, the driving unit, and the filter plate moving unit to supply power to the slurry dewatering device unit of the terephthalic acid wastewater.

According to such a slurry dehydration unit of the terephthalic acid wastewater, as the filter cloth is moved by connecting the driving unit and the filter cloth, the viscous cake is easily peeled from the filter cloth.

Terephthalic acid, dehydrator, flocculant

Description

Dehydrating apparatus unit and method for slurry of high purity terephthalic acid wastewater

1 is a conceptual diagram of a belt-type dehydrator for dewatering the slurry of terephthalic acid wastewater according to the prior art,

Figure 2 is a state of use of the slurry dewatering unit of the terephthalic acid wastewater according to an embodiment of the present invention,

3 is another use state of the slurry dehydration unit of the terephthalic acid wastewater shown in FIG.

4 is a flowchart of a slurry dewatering method of terephthalic acid wastewater according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: dewatering unit 110: first filter plate

111: electrode plate 120: second filtration plate

121: diaphragm 130: filter cloth

140: driving unit 150: driving roller

160: Cake

The present invention relates to a high purity terephthalic acid wastewater slurry dehydration unit and a dewatering method, and more particularly, to a dewatering unit and a dewatering method of a slurry containing excess activated sludge.

In the high purity terephthalic acid production process, a large amount of wastewater is generated, and a large amount of surplus activated sludge is generated.

Conventionally, the slurry containing the surplus activated sludge was treated by the following process. First, the slurry is concentrated by gravity in a concentration bath about 1-1.5% by volume relative to 100% by volume. The flocculating agent is added to the concentrated slurry so as to coagulate, and then the coagulated slurry is dehydrated using a belt-type dehydrator to be treated in the form of ocean dumping.

In general, as a facility for treating wastewater, a belt type dehydrator, a centrifugal separator, a press filter type, a screw press, a vacuum separation type, and the like have been developed. However, in the case of wastewater generated in the terephthalic acid manufacturing process, there was a difficulty in peeling the cake remaining after the slurry was dehydrated due to the viscosity of the slurry itself and the polymer coagulant used in the dehydration process. Accordingly, only the belt type dehydrator is used in the dehydration step of the terephthalic acid slurry.

Here, the belt-type dehydrator according to the prior art is shown in FIG.

1 is a conceptual diagram of a belt type dehydrator for dewatering a slurry of terephthalic acid wastewater according to the prior art.

The belt-type dehydrator 1 according to the prior art is provided with a supernatant cloth 2 and a lower fabric 3 passing between a plurality of pressure rollers 4. Here, the slurry of the terephthalic acid wastewater is introduced between the supernatant cloth 2 and the lower cloth 3 and dewatered by the pressure applied by the pressure roller 4. The belt-type dehydrator 1 according to the prior art dehydrates the slurry of terephthalic acid wastewater to have a water content of about 85% by volume with respect to 100% by volume in total. Since the cake dewatered after being dewatered by the belt-type dehydrator 1 according to the prior art has an excessive water content, its waste disposal amount is also excessive, which has a drawback in that the treatment cost is high.

The present invention has been made to solve the above problems, the slurry dewatering device of high purity terephthalic acid wastewater to efficiently agglomerate and dehydrate the slurry generated during the high-purity terephthalic acid manufacturing process, so that the dehydrated cake is easily peeled from the dewatering device The purpose is to provide a unit and a dewatering method.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention. Further objects and advantages of the invention may be realized by the means and combinations indicated in the claims.

The slurry dewatering device unit of the terephthalic acid wastewater of the present invention for achieving the above object comprises a first filtration plate having an electrode plate to charge on one surface; A second filtration plate provided on one side of the first filtration plate and having a space portion and a diaphragm for receiving the compressed water; and a second filter plate disposed between the first filtration plate and the second filtration plate, and located at an electrode of the first filtration plate. Filter cloth having a counter charge with the plate; A driving unit connected to one side of the filter cloth and driving the filter cloth to be moved; A filter plate moving part provided at one side of the first filter plate or the second filter plate and moving the first filter plate or the second filter plate from side to side; And a power supply unit connected to the first filtration plate, the filter cloth, the driving unit, and the filter plate moving unit to supply power.

Here, the filter cloth is provided on one side, it is preferable to further include a drive roller to move the filter cloth.

In order to achieve the above another object, the present invention is a coagulant input step to add a coagulant to the slurry to agglomerate the fine particles contained in the slurry; A filtration dehydration step of putting the slurry into which the flocculant is introduced into a filter cloth between the first filtration plate and the second filtration plate to dehydrate the slurry by filtration; A compression and electrolysis dehydration step of supplying opposite electrodes to the first filtration plate and the filter cloth, respectively, so that the slurry is dehydrated by compression and electrolysis; By descending the filter cloth, there is provided a slurry dewatering method of a terephthalic acid wastewater comprising a cake discharge step of discharging the cake in contact with the filter cloth.

Here, in the coagulant addition step, it is preferable to add 0.28 to 0.42% by volume of ferric chloride based on the total volume% of the concentrated slurry.

In addition, after the ferric chloride is added to the slurry in the flocculant input step, in order to increase the flocculation efficiency of the slurry, maintaining the pH of the slurry at 4.0 to 5.0 may bring good results.

In addition, the slurry dewatering method of the terephthalic acid wastewater, characterized in that further comprising the slurry concentration step of concentrating the slurry by gravity in the concentration tank as a step before the flocculant injection step.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

2 and 3, the slurry dehydration unit of the terephthalic acid wastewater according to an embodiment of the present invention will be described.

Figure 2 is a state of use of the slurry dewatering apparatus of terephthalic acid wastewater according to an embodiment of the present invention, Figure 3 is another state of use of the slurry dewatering apparatus of terephthalic acid wastewater shown in FIG.

Terephthalic acid wastewater slurry dewatering unit 100 according to an embodiment of the present invention is the first filter plate 110, the second filter plate 120, filter cloth 130, drive unit 140, filter plate moving unit (not shown), A power supply unit (not shown) and a driving roller 150 are provided.

The first filter plate 110 has an electrode plate 111 on one surface thereof. The electrode plate 111 is provided to be connected to the power supply unit to take an electrode. The electrode plate 111 according to the embodiment of the present invention receives a positive charge from the power supply unit. As such, by supplying electricity to the first filtration plate 110, the slurry can be dehydrated by electrolysis. Detailed description will be described later.

The second filtration plate 120 is provided on one side of the first filtration plate 110, one side is provided with a space portion 122 and the diaphragm 121 for receiving the compressed water, the compressed water discharge hole 123 is Is formed. Here, the space 122 is for accommodating the compressed water. When the diaphragm 121 is provided at one side of the space portion 122 and the compressed water is supplied to the space 122, the shape of the diaphragm 121 is changed by the pressure of the supplied compressed water. As the shape of the diaphragm 121 changes, the slurry introduced into the filter cloth 130 between the first filter plate 110 and the second filter plate 120 is compressed to be dehydrated.

The filter cloth 130 is provided to be positioned between the first filtration plate 110 and the second filtration plate 120. The filter cloth 130 is provided to allow electricity to pass through, and is connected to the power supply part to have an opposite charge with the electrode plate 111 of the first filtration plate 110. A negative charge is formed in the filter cloth 130 according to the embodiment of the present invention. When power is supplied to the first filter plate 110 and the filter cloth 130 in the power supply, the slurry introduced into the filter cloth 130 is dehydrated by electrolysis. In more detail, when the power supply unit supplies power to the first filtration plate 110 and the filter cloth 130, an electric field is formed in the slurry. In this process, the moisture particles in the slurry have a positive surface charge, and the slurry particles have a negative electrode charge. As a result, the slurry particles move toward the electrode plate 111 having a positive charge, and the moisture particles move to the filter cloth 130 that is the negative electrode, thereby dehydrating.

The driving unit 140 is connected to the filter cloth 130 so that the filter cloth 130 is moved. Accordingly, the cake 160 remaining after the slurry is dehydrated is easily peeled from the filter cloth 130. Detailed description will be described later.

The filter plate moving part may be provided in the first filter plate 110 or the second filter plate 120 to move the first filter plate 110 and the second filter plate 120 from side to side to narrow or widen the distance therebetween. have. That is, when the slurry flows between the first filtration plate 110 and the second filtration plate 120 and dehydration proceeds, the filter plate moving unit moves the first filtration plate 110 and the second filtration plate 120 to be located close to each other. . When the slurry is dehydrated and the cake 160 is discharged, the first filter plate 110 and the second filter plate 120 are moved away from each other, so that the cake 160 is easily discharged.

The drive roller 150 is connected to the power supply is driven. The drive roller 150 is provided to be in contact with the filter cloth (130). Accordingly, when the filter cloth 130 is moved by the drive unit 140, the cake between the filter cloth 130 is to be easily peeled off. Referring to the drawings in more detail, Figure 2 shows the state in which the cake 160 between the filter cloth 130 after the slurry is dehydrated. In this state, when the filter cloth 130 is further lowered by the driving unit 140, as shown in FIG. 3, the driving roller 150 guides the movement of the filter cloth 130, so that the folded filter cloth 130 is folded. Allow it to unfold. As such, the cake 160 stuck between the filter cloth 130 may be easily peeled off by the driving unit 140 and the driving roller 150.

Hereinafter, a slurry dehydration method of terephthalic acid wastewater according to an embodiment of the present invention will be described with reference to FIG. 4. Here, it will be described with reference to the slurry dehydration unit of the terephthalic acid wastewater according to an embodiment of the present invention.

4 is a flowchart of a slurry dewatering method of terephthalic acid wastewater according to an embodiment of the present invention.

Slurry dewatering method of terephthalic acid wastewater according to an embodiment of the present invention is a slurry concentration step (S101), flocculant input step (S102), filtration dehydration step (S103), compression and electrolysis dehydration step (S104), cake discharge step (S105) ).

The slurry concentration step (S101) is a step of allowing the slurry to be concentrated by gravity in the concentration tank. In the slurry concentration step (S101) according to the embodiment of the present invention, approximately 1% volume is reduced with respect to 100% by volume.

The flocculant input step (S102) is a process of flocculating the flocculant into the slurry concentrated in the slurry concentration step (S101). According to the present invention, the ferric chloride (FeCl ₃ ) is added to the slurry to agglomerate the slurry. Here, the ferric chloride used as a flocculant is added to 0.28 ~ 0.42% by volume relative to the total 100% by volume of the concentrated slurry. When ferric chloride is added to the slurry so as to deviate from the above range, the efficiency of aggregation decreases.

The fine particles in the slurry are anionic. When the ferric chloride is added to the slurry in this way, the Fe ³⁺ decomposed in the ferric chloride reacts with the fine particles to electrically neutralize the fine particles in the slurry. Here, Fe ³⁺ has a very low solubility in a solution of less than pH4. In addition, when the pH of the slurry is increased, Fe ³⁺ is converted to ferric hydroxide (Fe (OH) ₃ ), which causes difficulty in agglomeration of the anion-containing fine particles.

Accordingly, in order to more efficiently aggregate the slurry, ferric chloride as a flocculant is added to the slurry, and then the pH of the slurry is 4.0 to 5.0. Here, as can be seen from the above description, when the pH of the slurry is less than 4.0, the solubility of Fe ³⁺ is low fall of coagulation-flocculation of the particulate efficiency due to Fe ^3+. In addition, when the pH of the slurry exceeds 5.0, Fe ³⁺ is converted to ferric hydroxide (Fe (OH) ₃ ), thereby decreasing the efficiency of the aggregation reaction of the fine particles.

The filter dehydration step (S103) is a step in which the slurry is primarily dehydrated by filtration of the filter cloth 130 when the slurry is introduced between the filter cloths 130.

The compression and electrolysis dehydration step (S104) is a step in which the slurry located between the filter cloth 130 is dehydrated by compression and electrolysis. Here, the first filter plate 110 and the second filter plate 120 moves to be located close to each other. First, the dehydration process of the slurry by compression, the compressed water is supplied into the space portion 122 of the second filter plate (120). In the pressing and electrolytic dehydration step (S104) according to the embodiment of the present invention, the compressed water is supplied such that the inside of the second filtration plate 120 has a pressure of approximately 15 kg / cm. The pressurized water thus supplied pressurizes the diaphragm 121, and the diaphragm 121 is deformed under pressure to pressurize the slurry located at one side thereof. Accordingly, the slurry is dehydrated by pressure. Next, the dehydration process by electrolysis, first, power is supplied to the first filtration plate 110 and the filter cloth 130 to have opposite charges. According to the pressing and electrolytic dehydration step (S104) according to an embodiment of the present invention, the first filtration plate 110 is supplied with a positive charge, the filter cloth 130 is a negative charge. When power is supplied to the first filtration plate 110 and the filter cloth 130 in this way, an electric field is formed in the slurry. In this process, the moisture particles in the slurry have a positive surface charge. As a result, the moisture particles having the positive electrode surface charge move to the filter cloth 130 as the negative electrode, whereby the slurry is dehydrated by electrolysis.

The cake discharge step (S105) is a step of discharging the remaining cake 160 after the slurry is dehydrated in the compression and electrolysis dehydration step (S104). In the pressing and electrolytic dehydration step (S104), the cake 160 compressed between the filter cloths 130 exists in a state of being attached to the filter cloth 130. Since the cake 160 is not easily peeled from the filter cloth 130, the filter cloth 130 and the driving unit 140 are connected to allow the filter cloth 130 to move up and down. In addition, by providing the driving roller 150 on one side of the filter cloth 130, so that the filter cloth 130 is folded and unfolded by the drive roller 150 while the filter cloth 130 is moved up and down by the drive unit 140. do. As the filter cloth 130 moves in this way, the cake 160 stuck between the filter cloth 130 may be easily peeled off.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

Example 1

In the embodiment of the present invention was tested using a solution containing 35% by volume of ferric chloride relative to 100% by volume of the total solution. Here, the slurry obtained in the terephthalic acid production process was used in four experimental groups in the same manner.

First, a solution containing ferric chloride was added to each of the slurry of each of the four experimental groups.

Here, the solution containing 35% by volume of ferric chloride was 0.6% by volume, 0.8% by volume, 1.0% by volume, 1.2% by volume with respect to 100% by volume of the slurry.

In addition, after adding ferric chloride, ferric chloride was added so that the pH of the solution was 4.5 to more effectively aggregate the fine particles, and then aggregation occurred for 50 minutes. Slurry injection time is very important because about 20 minutes after the aggregation occurs, the aggregated particles are broken.

The agglomerated solution is introduced into a dehydration apparatus according to an embodiment of the present invention, dehydrated by primary filtration, and then pressurized water is supplied to a pressure of 15 kg / cm, and an electrode is attached to the electrode plate and the filter cloth. Supplied. Accordingly, the slurry was dehydrated in the dehydrator.

After dehydration, the moisture content in the cake discharged by the driving unit and the driving roller was measured, and is shown in Table 1.

Here, the moisture content of the cake was measured by the dry sample weight reference method, which expresses the moisture weight ratio to the dry weight of the sample in percent (%).

Injection concentration (solution containing 35 vol% ferric chloride) Water content 1.2% by volume 68% 1.0% by volume 64% 0.8% by volume 70% 0.6% by volume 71%

Referring to Table 1 above, it can be seen that the water content of the cake is the lowest in the experimental group in which 1.0 vol% of the ferric chloride solution was added to 100 vol% of the total slurry. Accordingly, it can be seen that in the experimental group in which the ferric chloride solution was added at 0.8% by volume to 1.2% by volume, the slurry was effectively aggregated to increase the dehydration efficiency of the slurry.

Here, the ferric chloride solution is a solution containing 35% by volume of ferric chloride relative to 100% by volume of the total solution, so that the water content of the cake when 0.35% by volume of ferric chloride is added to 100% by volume of the total slurry It appears that the lowest, when the ferric chloride is added 0.28 ~ 0.42% by volume to 100% by volume of the total slurry, it can be seen that the slurry is effectively aggregated.

As mentioned above, although this invention was demonstrated by the limited embodiment and drawing, this invention is not limited by this, The person of ordinary skill in the art to which this invention belongs, Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

As described above, according to the slurry dewatering unit and the dewatering method of the terephthalic acid wastewater of the present invention,

First, by using 0.28 to 0.42% by volume of ferric chloride as a coagulant with respect to 100% by volume of the entire slurry, it is possible to more efficiently agglomeration reaction and COD removal of the slurry.

Second, power is supplied to the first filtration plate and the filter cloth, respectively, to simultaneously compress and dehydrate the slurry by electrolysis, thereby lowering the water content of the discharged cake, thereby reducing the throughput of the cake and reducing economic efficiency. Will have an effect.

Third, as the filter cloth is moved by connecting the driving unit and the filter cloth, the viscous cake is easily peeled from the filter cloth.

Fourth, it is possible to flexibly cope with the processing capacity by using a plurality of dehydration unit units connected in parallel to meet the needs of the user.

Claims (6)

A first filtration plate having an electrode plate so as to be charged on one surface thereof and movable left and right; A second filtration plate provided at one side of the first filtration plate and provided with a space portion and a diaphragm receiving the compressed water at one side thereof and movable left and right; A filter cloth positioned between the first filter plate and the second filter plate and having a charge opposite to that of the electrode plate of the first filter plate; A driving unit connected to one side of the filter cloth and driving the filter cloth to be moved; A filter plate moving part provided at one side of the first filter plate or the second filter plate and moving the first filter plate or the second filter plate from side to side; And And a power supply unit connected to the first filter plate, the filter cloth, the driving unit, and the filter plate moving unit to supply electric power. The method of claim 1, One side of the filter cloth, slurry dewatering device unit of terephthalic acid waste water, characterized in that it further comprises a drive roller for moving the filter cloth. A coagulant input step of injecting a coagulant into the slurry to aggregate the fine particles contained in the slurry; A filtration dehydration step of putting the slurry into which the flocculant is introduced into a filter cloth between the first filtration plate and the second filtration plate to dehydrate the slurry by filtration; Compression and electrolysis dehydration step of supplying opposite electrodes to the first filtration plate and the filter cloth, respectively, so that the slurry is dehydrated by pressing and electrolysis. And a cake discharge step of discharging the cake contacted with the filter cloth by lowering the filter cloth. The method of claim 3, wherein In the previous step of the flocculant input step, Slurry dewatering method of terephthalic acid waste water, characterized in that it further comprises a slurry concentration step of concentrating the slurry by gravity in the concentration tank. The method of claim 4, wherein The flocculant input step is a slurry dewatering method of terephthalic acid wastewater, characterized in that the step of adding 0.28 ~ 0.42% by volume of ferric chloride relative to the total 100% by volume of the slurry concentrated through the slurry concentration step. The method of claim 5, After the ferric chloride is added to the slurry in the flocculant input step, in order to increase the flocculation efficiency of the slurry, the pH of the slurry is maintained at 4.0 to 5.0, wherein the slurry dewatering method of the terephthalic acid wastewater.

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