KR20030086740A - Driving method for agglutination reactor according to gtc function - Google Patents

Abstract

PURPOSE: Provided is a method for controlling a coagulator based on GTC function, wherein G is a value determined by inflow water temperature, T is a retention time and C is turbidity. CONSTITUTION: The method comprises the steps of detecting inflow water temperature, water inflow rate, and turbidity, and adjusting revolution per minute (RPM) of a motor of a mixer in a coagulation tank based on f(GTC), here G is a value determined by inflow water temperature, T is a retention time and C is turbidity, and wherein the f(GTC) is expressed as an equation of G·C¬0.5·T¬0.5.

Description

DRAGING METHOD FOR AGGLUTINATION REACTOR ACCORDING TO GTC FUNCTION}

The present invention is a method for increasing the flocculation efficiency of the sludge particles in a water treatment plant flocculation plant, more specifically, to operate at a speed calculated in a constant function according to the water temperature, turbidity, inflow water, and other influence factors. The present invention relates to a control method of agglomerator operation by a GTC function which makes the coagulation efficiency larger than the method and enables stable purified water production.

In general, the flocculator in the water purification plant has to make a large, heavy and solid flocks while colliding with each other the fine flocks in the raw water, so that the sedimentation and filtration are performed smoothly. In order to form a heavy floc and a large floc, an appropriate particle and particle collision have to be made. For this purpose, an appropriate stirring speed and agitation time are absolutely necessary.

In particular, the basic formulas related to temperature and speed are the formulas of Camp and Stein, and the formation of the floc is appropriate for the number of collisions between particles and particles, and basically the G-value (Velocity Gradient: Average speed gradient). However, if the G value is excessive, it is said that there is a limit to increasing the G value because the floc is destroyed by the increase of shear force rather than the growth of the floc, and it is preferable to decrease the G value step by step from the slope aggregation to the downstream. In addition, since the inflow flow rate is related to the residence time of the flocculation basin, it is desirable to reduce the shear force, which is the rotational speed, according to the decrease of the inflow flow rate.The turbidity tends to break rapidly according to the increase number after a certain range. The shear force, which is the rotational speed, should be reduced, and the speed adjustment should be made in consideration of other influencing factors (water quality sludge property, PH factor, etc.).

Conventional Utility Model Publication No. 94-1655 maintains only a constant velocity gradient value that is a function of temperature, and Utility Model Publication No. 137208 allows the rotational speed to be operated by installing a viscosity measurement means directly in water. -0012526 is determined by GT (the product of velocity gradient and residence time), which is the optimum state, and simultaneously measures the viscosity of the inflow flow rate and the flocculation water, and uses it to calculate the impeller rotation speed by making the product of G value and residence time constant. It was allowed to operate at this value.

Utility Model Publication Nos. 94-1655 and 137208 use only temperature or viscosity, so changes in residence time of water, changes in turbidity, and other influencing factors are not applied. 2000-0012526 is more efficient than the utility model, but there is no application of changes in turbidity and other influence factors, causing problems of floc formation due to poor stirring when the water quality changes.

The higher the turbidity (suspension concentration) in water, the closer the particle is to the particle, so the chance of collision of particles during agitation increases, so the floc must be grown with slow agitation. This is because if the agitator is not stirred properly, the floc generated by the water flow is destroyed again.

Recently, some documents have a problem that the scope of application of temperature, flow rate, and turbidity should be recognized, but there are few specific application methods.

The present invention has been made to improve such a problem, the inflow water temperature, inflow flow rate, inflow turbidity of the flocculation basin, the stirrer motor for rotating the impeller of the flocculator is affected by the inflow water temperature G value, inflow turbidity C, retention An object of the present invention is to provide a method for controlling agglomerator operation by a GTC function, which can improve the flocculation efficiency of sludge particles by controlling the rotation to be set by the rotation speed set by a function taking time T as a factor.

1 is a block diagram of the operation control unit according to an embodiment of the present invention.

※ Explanation of code for main part on drawing ※

10: GTC setting unit 20: temperature detector

30: flow rate detection unit 40: turbidity detection unit

41: synthetic influence factor correction unit 50: speed calculator

60: PID controller 70: inverter

80: drive motor

In order to achieve the above object, the present invention is to rotate the agitator impeller of the agglomerator in the water treatment plant using an electric motor and a reducer, at the same time to measure the inlet water temperature, inflow flow rate, inflow turbidity of the flocculation paper, Agitator motor is operated such that the stirrer motor is rotated at a rotational speed set by a function f (GTC) = const taking G value, inlet turbidity C, and residence time T as factors that influence the inlet water temperature. Provides a driving control method.

For example, consider the flocculant water temperature, turbidity (suspension concentration), influent volume, and By applying = const to the proportional operation, the coagulation effect is maximized in the coagulation paper.

The formula induction of = const is as follows.

The average velocity G value is known and is as follows.

=

P: manual force (Kw)

g: acceleration of gravity (9.8M / S ² )

Cd: Resistance coefficient of agglomerator wings (1.5-1.8)

A: flocculator wing area ㎡

υ: Wing speed (M / S)

= Density of fluid (1,000㎏ / ㎥)

= Viscosity of water (kg / msec × 10 ^-3 :)

V = volume of coagulation tank (㎥)

When the optimal G value of the aggregated paper is determined in Equation 1, Cd, A, V, Since the value is constant, P, υ is determined by the viscosity of water. This method is one conventional method,

In the above equation, both sides are multiplied by the residence time T (T = V / Q) of the flocculation paper, where V is a constant treatment, and P, v is determined to be linked to G value and Q (flow rate).

Considerations for agglomerators should consider not only water temperature and flow rate but also turbidity with varying variations.

In consideration of design, turbidity is usually designed to operate at low turbidity, and high turbidity requires slow agitation as the distance from the particles is closer and the resulting flocs are destroyed in the middle. At this time, the G value operation or the GT value operation is not automatic operation, and a problem arises in that manual operation is performed by adjusting the rotation speed separately.

Because of these problems, efficient use of G, C, and T values It would be desirable to have a constant value, which can be written as

Substituting V = QT in equation (1) and turbidity C is inversely proportional to Q, If you multiply by, you get

=

= = const

If the rotation speed υ is obtained, it is as follows.

υ = k1 xu ^1/3 x Q ^1/3 x C ^-1/3

Since the viscosity function u ^1/3 is the temperature function f (t) ^2/3 , the following equation is obtained.

υ = k2 xf (t) ^2/3 x Q ^1/3 x C ^-1/3

In Equation 5, the rotational speed is proportional to the temperature function f (t) 2/3 power, proportional to 1/3 power of the flow rate, and proportional to -1/3 power of turbidity. You can operate with the value constant.

In other words, the flocculation basin water temperature is measured, the inflow water flow rate is measured directly and indirectly, and the turbidity is measured directly and indirectly.

In addition, when P is applied in Equation 5 in consideration of various other influence factors P, the following equation is obtained.

υ = k2 xf (t) ^1/3 x Q ^1/3 x C ^-1/3 x P

In the temperature range of 0 degrees to 25 degrees, f (t) ^2/3 in Equation 5 is approximated to f (t) = (1-(21 xt) / 2500). .

The agglomerator driven in this way corresponds to changes in water temperature, turbidity, flow rate, etc. to maximize the coagulation efficiency and to make power saving and operation management easy.

Hereinafter, an embodiment based on the accompanying drawings, the control device operated by the GCT function of the flocculator according to the present invention will be described in detail as follows.

Figure 1 shows the configuration of the control device operated by the GCT function of the agglomerator according to the present invention, and set the GC ^1/2 T ^1/2 value in the range of 800 ~ 8000 in the GCT setting unit 10 of the control panel When the signal of the temperature detector 20, the signal of the flow rate detector 30, and the signal of the turbidity detector 40 are simultaneously detected and transmitted through the R / I converter, the GC ^1/2 T ^{1 /} The output signal of the number of revolutions calculated by ^two values is transmitted to the inverter 70 through the PID controller 60 to rotate the drive motor 80 of the stirrer.

Referring to the operating state according to an embodiment of the present invention configured as described above are as follows.

Of this control panel in const

The operating data is taken as the maximum rotational speed with a G value of 60, a turbidity of 20 degrees (maximum rotational speed hereafter), and a delay time of 2400 seconds or less.

At this time The value is = 60 x 20 ^1/2 x 2400 ^1/2 = 13145,

On the control panel Set it to 13145 as the value.

In Equation 5

υ (load rotation speed of 4-pole motor) = 1700 xf (t) x Q ^1/3 x C ^-1/3

At this time, if 80% of the design quantity (design of the retardation time 2400 seconds), which is the maximum value, is introduced by the flow signal, the turbidity is 40 degrees and the water temperature is 20 degrees,

At this time, the transmission output speed in the GCT control panel and the rotation RPM of the motor are calculated as 1287 RPM, which is 1700 x (1-(21 x 20) / 2500) x 0.8 ^1/3 x (40/20) ^-1/3 Will be printed out.

In the configuration diagram of the control device operated by the GCT function of the coagulator according to the present invention, the signal from the synthesis influence factor correction unit 41 may be input to the speed calculator 50 by considering the synthesis influence factor P separately. The rotation speed of the motor at this time

υ (load revolution of 4-pole motor) = 1700 xf (t) x Q ^1/3 x C ^-1/3 x P

In this case, when 80% of the maximum design quantity (design of the designation time of 2400 seconds) flows in by the flow signal, the turbidity is 40 degrees, the water temperature is 20 degrees, and the value applied by various other influence factors is 0.95. In the same way, the rotating RPM of the motor is output at the calculated speed of 1222 RPM which is 1700 x (1-(21 x 20) / 2500) x 0.8 ^1/3 x (40/20) ^-1/3 x 0.95.

The GCT value controller of the coagulated paper that is operated in this way can cope with the change of various factors affecting the formation of the flocs, thereby further improving the problems caused by controlling only the conventional temperature and flow rate. Therefore, it is possible to combine high technology with the production of water, and to solve the problem of stopping the operation for several days due to the flop destruction caused by the change of high turbidity. Was done.

Claims (5)

In rotating the agitator impeller of the agglomerator in a water treatment plant using an electric motor and a reduction gear, the inflow water temperature, the inflow flow rate and the inflow turbidity of the agglomeration station are simultaneously measured, and the agitator motor is affected by the inflow water temperature. A method of controlling agglomerator operation by a GTC function, characterized in that it is operated to rotate at a rotation speed set by a function f (GTC) = const having a turbidity C and a residence time T as a factor. The method of claim 1, wherein the function f (GTC) is a product of the G value, 1/2 power of inflow turbidity and 1/2 power of the residence time. A method for controlling agglomerator operation by a GTC function, characterized in that it is configured to rotate. The method according to claim 1, wherein a separate influence factor is added to the operation control value of the agitator motor set by the GCT function to operate at the control value set by the GCTP function. . The rotational speed of the stirrer motor for the rotation of the impeller according to claim 2 υ = k2 xf (t) ^2/3 x Q ^1/3 x C ^-1/3 (where wing velocity (M / S): υ, C: inflow turbidity, flow rate: Q, temperature function: f (t ), and k2: constant) to operate the coagulator operation control method according to the GTC function. The rotation speed of the stirrer motor for the rotation of the impeller according to claim 3 υ = k2 xf (t) x Q ^1/3 x C ^-1/3 x P (where P: influence factor, wing velocity (M / S): υ, C: inflow turbidity, flow rate: Q, temperature function : F (t), k2: constant) to operate the agglomerator operation control method according to the GTC function characterized in that the operation.