KR20070025159A - On-line ph system for waste water treatment process - Google Patents

Abstract

An on-line pH system of a waste water treatment process is provided to unplug solid floating matters in a sample line by using pure water, automatically clean a floating matter membrane of a pH sensor measuring pH of waste water, and automatically control unplugging of the sample line, thereby effectively managing concentration of waste water, measuring accurate pH data, and reducing time and cost. A tank(110) stores waste water. A pH measuring unit(120) measures pH of waste water supplied from the tank. A line cleaning unit(130) unplugs a sample line connecting the tank with the pH measuring unit. A holder cleaning unit(140) cleans the inside of the pH measuring unit. The line cleaning unit includes a pure water supply unit(131) supplying pure water for removing a solid accumulated in the sample line, a first control valve(133) opened to supply pure water when the sample line is plugged, and a second control valve(132) opened when waste water is introduced to the pH measuring unit from the tank and closed when the sample line is plugged. The pH measuring unit includes a holder(121) temporarily storing waste water introduced from the tank, a pH sensor(122) embedded in the holder for measuring pH of waste water, and a spray nozzle(123) cleaning the pH sensor and the holder. The holder cleaning unit includes a caustic soda supply unit(141) injecting caustic soda for removing a floating matter membrane of the pH sensor, a purified water supply unit(142) supplying purified water injected in removing caustic soda, a third control valve(144) controlling supply and interruption of caustic soda, a fourth control valve(143) controlling supply and interruption of purified water, and a fifth control valve(145) opened in order to supply caustic soda and purified water when the inside of the holder is cleaned.

Description

On-line pH system for waste water treatment process

1 is a process diagram showing a pH system of the anaerobic reactor wastewater treatment process in the terephthalic acid manufacturing process according to an embodiment of the present invention,

2 is a process diagram showing a control unit that can control the pure water supply when unplugging the line cleaning unit according to an embodiment of the present invention.

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

Flowchart for Online pH System of Wastewater Treatment Process

110 ... waste water tank 120 ... pH measuring unit

130 ... line cleaning unit 140 ... holder cleaning unit

121 ... holder 122 ... pH sensor

123 Spray nozzle 131 Pure water supply

132 ... 2nd control valve 133 ... 1st control valve

134 Drain valve 141 Caustic soda supply

142 Purified water supply section 143 4th control valve

144 ... third control valve 145 ... third control valve

150 ... control unit 151 ... flow meter

152 Sensors 153 Controller

154 ... valve

The present invention relates to a hydrogen ion concentration (hereinafter referred to as pH) measurement system, and more particularly to a system for measuring the pH concentration of the anaerobic reactor wastewater treatment process in the terephthalic acid manufacturing process. .

In general, the manufacturing process of high purity terephthalic acid (PTA) can be largely divided into an oxidation process, a purification process and a post process.

First, the p-xylene (para -Xylene) in the oxidation step by oxidation of the solvent is acetic acid and metal catalyst to produce an intermediate product crude terephthalic acid (Crude Terephthalic Acid).

Next, since a large amount of impurities are contained in the crude terephthalic acid produced in the oxidation process, impurities are removed through a reduction reaction in the purification process.

Finally, the post-process consists of five processes of feed preparation dissolution and hydrogenation, crystallization, separation and product recovery in which a terephthalic acid aqueous solution is reacted with hydrogen in a catalyst layer under high temperature and high pressure. .

Meanwhile, in the refining process, waste water is generated while impurities are removed, and the waste water is discharged to the river or the sea through a waste water treatment process (WWT).

However, the wastewater generated in the field contains various foreign substances, and in particular, the sample line from which the sample is collected due to the solid suspended solids is frequently plugged.

Therefore, in the related art, it is not common to construct an on-line facility, and a separate site installation operation of collecting wastewater periodically and managing pH concentration of wastewater introduced into an anaerobic reactor in a laboratory has been common.

However, this method is a waste of manpower to wash the solid suspended solids attached to the pH sensor, the cost loss due to the reduction of equipment life due to frequent maintenance. In addition, it is not only cumbersome to manage the pH concentration by taking a sample periodically, and the more processes to be managed, the more time and money it takes to process them.

In addition, there is a problem that the measured data is not accurate when measuring the pH concentration in the laboratory.

The present invention was created to solve the above problems, it is possible to effectively manage the pH concentration of the incoming wastewater, to measure the accurate pH data, and to reduce the time and cost by the simple treatment process There is this.

Other objects and advantages of the present invention will be described below, and will be appreciated by the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the claims.

PH system of the wastewater treatment process of the present invention for achieving the above object, the tank and the wastewater is stored; A pH measuring unit for measuring the pH of the wastewater supplied from the tank; A line cleaning unit for unplugging the sample line connecting the tank and the pH measuring unit; And a holder cleaning unit for cleaning the inside of the pH measuring unit.

The line cleaning unit may include: a pure water supply unit supplying pure water to remove solid matter accumulated in the sample line; A first control valve opened to supply pure water when plugging the sample line; And a second control valve which is opened when the wastewater flows from the tank into the pH measuring unit and is closed when the sample line is plugged.

In addition, the pH measuring unit, the waste water flows in from the tank holder is temporarily stored; A pH sensor embedded in the holder and measuring pH of the wastewater; It is preferable to include a spray nozzle for cleaning the inside of the pH sensor and the holder.

Furthermore, the holder cleaning unit includes: a caustic soda supply unit for inputting caustic soda to remove the floating film of the pH sensor mounted inside the holder; A purified water supply unit for supplying purified water input when removing caustic soda; A third control valve controlling supply and shut-off of caustic soda; A fourth control valve controlling supply and shutoff of purified water; And a fifth control valve which is opened to allow supply of caustic soda and purified water during cleaning of the holder.

On the other hand, the line cleaning unit, it is preferable that the drain valve for discharging a part of the waste water remaining in the sample line when unplugging.

In addition, a flow meter for measuring the flow rate of waste water passed to the sample line; A sensor for detecting an abnormal signal when the measured value of the flow meter measured when unplugging is below a predetermined level; A controller receiving the signal sensed by the sensor; And it is preferable that the control unit further comprises a valve that is opened by the control of the controller to supply the pure water when unplugging.

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 present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to explain their invention in the best way. Based on the principle that 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 the most preferred embodiment 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.

1 is a process chart showing a pH system of the wastewater treatment process according to a preferred embodiment of the present invention.

2 is a process chart showing a control unit that can control the pure water supply when unplugging the line cleaning unit according to an embodiment of the present invention.

First, referring to FIG. 1, the pH system 100 of the wastewater treatment process according to an embodiment of the present invention includes a tank 110, a pH measuring unit 120, a line cleaning unit 130, and a holder cleaning unit 140. ).

The pH measuring unit 120 measures the pH of the wastewater supplied from the tank 110 using the pH sensor 122 mounted inside the holder 121, and then sends a signal to a pH meter (not shown). The numerical value is shown. In addition, by using the injection nozzle 123 that can be sufficiently injected into the holder to clean the float membrane of the pH sensor 122. Thus, the pH meter allows accurate data to be obtained on-line about the pH concentration of the wastewater.

The second control valve 132 in the line cleaning unit 130 is opened when the waste water flows into the pH measuring unit 120 from the tank 110. Next, since the pressure of the sample line is high due to the suspended matter in the wastewater, the drain valve 134 is opened to reduce the pressure, and a part of the wastewater is discharged and then closed. On the other hand, to measure the pH concentration of the wastewater introduced from the holder 121, to open the drain valve 134 of a portion of the wastewater to reduce the pressure of the sample line before unplugging the sample line with pure water (131). To discharge.

Next, the second control valve 132 is closed to block the inflow of waste water injected into the holder 121. After this operation the sample line is 7kg / cm ² In order to unplug the pure water 131 under pressure, the first control valve 133 is opened to supply pure water 131. Thus, the suspended matter in the sample line can be removed. In addition, by closing the drain valve 134 while the pure water 131 is injected, the pressure of the sample line may be increased to increase the effect of unplugging. Finally, the first control valve 133 is closed to block the supply of pure water 131, and the drain valve 134 is opened to discharge the pure water remaining in the sample line.

Hereinafter, look at the holder cleaning unit according to an embodiment of the present invention.

In the holder cleaning unit 140, the fifth control valve 145 is opened to supply caustic soda 141 and demineralized water 142 when the holder 121 is cleaned. Next, the third control valve 144 is opened, the caustic soda 141 is injected, the caustic soda 141 is passed through the injection nozzle 123 at a pressure of 3kg / cm ² , the holder 121 ) To flush the float membrane of the pH sensor 122. When the washing is finished, the third control valve 144 is blocked. After this operation, the fourth control valve 143 is opened and purified water 142 flows at a pressure of 3 kg / cm ² to remove the caustic soda 141 which becomes a problem of data error when measuring the pH concentration of the next wastewater. do. After the caustic soda 141 is completely removed, the fourth control valve 143 and the fifth control valve 145 are blocked.

FIG. 2 is a process diagram illustrating a controller 150 capable of controlling pure water supply during unplugging of the line cleaning unit 130 shown in FIG. 1.

Referring to FIG. 2, the controller 150 includes a flow meter 151, a sensor 152, a controller 153, and a valve 154 that controls a pure water supply.

The flow meter 151 measures the flow rate of the wastewater passed to the sample line, and the sensor 152 detects an abnormal signal when the measured value of the flow meter 151 measured at the time of unplugging is below a predetermined level. . In addition, the controller 153 receives the signal sensed by the sensor 152, and the valve 154 for adjusting the pure water supply is opened by the control of the controller 153 when unplugging.

Therefore, according to the process of the control unit 150, when the floating material of the sample line is formed and there is a plugging phenomenon, the on-line system of the anaerobic reactor wastewater treatment that can be unplugged by automatically supplied with pure water 131 is applied can do.

According to the online pH system of the wastewater treatment process of the present invention, the solids suspended in the sample line in the line cleaning unit can be unplugged with pure water. In addition, it is possible to reduce the waste of manpower used by automatically washing the suspended film of the pH sensor for measuring the pH of the waste water through the holder cleaning unit. Finally, the unplugging of the sample line may be automatically controlled through a control unit connected to the line cleaning unit.

Therefore, it is possible to effectively manage the pH concentration of the incoming wastewater, the treatment process is simple to reduce the time and cost, there is an advantage that can obtain accurate pH measurement data of the wastewater.

Claims (6)

A tank in which waste water is stored; A pH measuring unit for measuring the pH of the wastewater supplied from the tank; A line cleaning unit for unplugging the sample line connecting the tank and the pH measuring unit; On-line pH system of the wastewater treatment process comprising a holder cleaning unit for cleaning the inside of the pH measuring unit. The method of claim 1, wherein the line cleaning unit, A pure water supply unit for supplying pure water to remove solids accumulated in the sample line; A first control valve opened to supply pure water when plugging the sample line; And And a second control valve opened when the wastewater flows from the tank to the pH measuring unit and closed when the sample line is plugged. Online pH system for wastewater treatment. According to claim 1 or 2, wherein the pH measuring unit, A holder for temporarily storing waste water from the tank; A pH sensor embedded in the holder and measuring pH of the wastewater; On-line pH system of the wastewater treatment process, characterized in that it comprises a spray nozzle for cleaning the inside of the pH sensor and the holder. According to any one of claims 1 to 3, wherein the holder cleaning unit, A caustic soda supply unit for introducing caustic soda to remove the floating film of the pH sensor mounted inside the holder; A purified water supply unit for supplying purified water input when removing caustic soda; A third control valve controlling supply and shut-off of caustic soda; A fourth control valve controlling supply and shutoff of purified water; And On-line pH system of the wastewater treatment process characterized in that it comprises a fifth control valve which is opened to allow the supply of caustic soda and purified water during the cleaning of the holder. The method of claim 2, wherein the line cleaning unit, On-line pH system of the wastewater treatment process characterized in that it further comprises a drain valve for discharging a portion of the wastewater remaining in the sample line when unplugging. The method of claim 1, A flow meter for measuring the flow rate of the wastewater passing through the sample line; A sensor for detecting an abnormal signal when the measured value of the flow meter measured when unplugging is below a predetermined level; A controller receiving the signal sensed by the sensor; And On-line pH system of the wastewater treatment process characterized in that the control unit further comprises a valve that is opened by the control of the controller to supply the pure water when unplugging.

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