KR20020078581A - Be United Stirring Type Oxygen Produced Instrument - Google Patents

Abstract

PURPOSE: An agitation integral air diffusing unit is provided which reduces an initial amount invested and operating cost and increases efficiency by integrally forming a diffusion part for diffusing bubbles on an agitator of an aeration tank for oxidation treating waste sludge. CONSTITUTION: The agitation integral air diffusing unit(1) comprises a pump for sucking in air from an air tank or the outside; a transfer pipe(3) one end of which is coupled to the pump to transfer the air sucked in; an agitation part comprising an air injection pipe(21) for injecting the air transferred from the transfer pipe into an aeration tank, and a porous diffusing stone(22) which is coupled to the lower part of the air injection pipe(21) to inject air passing through the air injection pipe(21) into the aeration tank; and a coupler(4) in which a penetration hole(41) for connecting the transfer pipe(3) inserted side surface of the coupler(4) to the air injection pipe(21) inserted lower part of the coupler(4) is formed, and into the lower part of which a bearing(42) is inserted so that the air injection pipe(21) is rotated, wherein the agitation integral air diffusing unit(1) further comprises a motor that is installed by being contacted with the outer surface of the air injection pipe(21), is fixed by a support, and conveys power so that the air injection pipe(21) is rotated around a shaft.

Description

Agitation integrated diffuser device {Be United Stirring Type Oxygen Produced Instrument}

The present invention relates to a stirring integrated diffuser, and more particularly, to an apparatus in which a diverging portion for discharging bubbles is integrally formed in a stirring device of an aeration tank for waste slurry oxidation treatment.

Aeration technology using air or oxygen has been applied to various processes such as oxidation and biological wastewater treatment, microbial culture process, petrochemical process, fermentation industry, and three-phase process using catalysts. .

Conventional aeration device used in the aeration technology consists of an aeration tank containing waste sludge, a diffusion stone for releasing air and a stirring device for mixing the waste slurry and air, the air emanates from the diffusion stone formed at the bottom of the aeration tank Air is mixed with the waste slurry due to the rotation of the stirring device, and the oxidation of the waste slurry proceeds rapidly as the amount of dissolved oxygen in the aeration tank increases.

In the above abandonment technology, the size and retention of bubbles, the mixing and contacting effects of gas-liquid, etc. are known to have important effects on the gas-liquid mass transfer rate and the material transfer rate. In order to increase the overall material transfer coefficient by changing these factors, various technologies such as adding bubble grinding material, liquid stirring, and reactor structural improvement have been actively studied at home and abroad. Particularly, the liquid agitation technique is known to increase the gas-liquid contact area by finely crushing the bubble size and to increase the gas-liquid contact effect due to the fluidization of the liquid. The search for a technology that can be applied is expected to be a very meaningful study.

In addition, the material-delivery rate between the gas and liquid in the aeration process is often the rate step that determines the efficiency of the overall process, which is a very important factor in the design of the device. The research on the development of a unique abandonment device with material transfer characteristics, economy and efficiency is expected to be of great value.

In particular, in the case of wet flue gas desulfurization, the spread of air pollution emission is expected to increase, but due to the high dependence on foreign technology, there is almost no operational data on oxidation of waste slurries. As operating costs are required, securing of effective abandonment technology is urgently required.

Accordingly, the present invention has been made to solve the above problems,

It combines the liquid stirring technology to the oxidation process of the waste slurry to integrate the air disperser which separates the existing air distribution and agitation.

Since the diffuser of the present invention does not require diffusion stones installed at the bottom of the aeration tank, the capacity of the aeration tank is reduced, facility costs are simplified, the device is simplified, and an efficient vortex is formed for the gas-liquid contact, thereby increasing the gas-liquid contact area and contact frequency. It is possible to reduce the aeration tank capacity by increasing the gas-liquid mass transfer speed, and to reduce the operating cost due to the initial investment cost and the decrease of air flow, thereby providing a device with economical efficiency and efficiency.

Stirring integrated diffuser of the present invention having such a purpose,

A pump for sucking air from the air tank or the outside; A transfer pipe for transferring the air sucked into the pipe body having one end coupled to the pump; An agitating unit including an air injection pipe for injecting the air transferred from the transfer pipe into the aeration tank, and a porous acid stone coupled to a lower portion of the air injection pipe to inject air passing through the air injection pipe into the aeration tank; A motor installed in contact with an outer surface of the air injection pipe, fixed by a support, and configured to transmit power so that the air injection pipe can rotate about an axis; A through hole is formed in the side from which the feed pipe is inserted into the air injection pipe is inserted into the lower portion, it is composed of a coupler to insert the bearing in the lower portion so that the air injection pipe can rotate.

1 is a perspective view of a stirring integrated diffuser device according to the present invention.

2 is a cross-sectional view showing an operating state of the stirring integrated diffuser device according to the present invention.

Figure 3 is an operating state of the main part of the stirring integrated diffuser device according to the present invention.

4 is a conceptual diagram of the air transfer bilayer theory.

Figure 5 is a plan view showing an embodiment of the oxygen transfer experiment oxygen diffuser.

Figure 6 is a comparison of the performance of the stirring integral and separation type for the overall mass transfer coefficient when the air supply amount changes.

Figure 7 is a comparison of the performance of agitation integral type and separation type for the overall mass transfer coefficient when the stirring speed changes.

8 is a comparison of the performance of the stirring integral and separation type for the overall mass transfer coefficient when the liquidus temperature changes.

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

1: Air diffuser 2: Stirring part

3: transfer pipe 4: coupling sphere

5: motor 6: pump

21: air injection pipe 22: mountain stone

23: auxiliary pipe 41: through hole

42: bearing 101a, 101b: air inlet valve

102: hydraulic control device 103: aeration tank

104: constant temperature water tank 105: diffused stone

106: DO measuring instrument 107: motor support

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of the stirring integrated diffuser, Figure 2 is a stirring integrated diffuser operating state, Figure 3 is a plan view showing a rotating state of the stirring unit from the top, Figure 4 is an air for understanding the present invention A conceptual diagram of a transfer double membrane theory is illustrated, and FIG. 5 is a plan view showing an experimental apparatus for performance testing of agitation unitary type and separation type, and FIGS. 6, 7 and 8 show changes in air supply amount, stirring speed, and liquidus temperature, respectively. When compared to the overall mass transfer coefficient of the graph showing the performance of the stirring integral and separation type performance.

The stirring integrated diffuser device 1 according to the present invention includes a pump 6 for sucking air from an air tank or an outside, a transfer pipe 3 for transferring the air sucked from the pump, and a mixing portion of waste slurry. (2) and the coupler (4) connecting the transfer pipe (3) and the stirring unit (2).

The stirring unit 2 is composed of an air injection pipe 21 and an acidic stone 22 coupled to the lower end of the air injection pipe, and the air injection pipe 21 has a long longitudinal direction to be inserted into the waste slurry. It is a tubular body, and the lower end portion is formed with an auxiliary pipe 23 protruding to the outside of the axis around the axis of the air injection pipe, the space formed to move the air inside the air injection pipe is connected to each auxiliary pipe.

At the end of the auxiliary pipe 23 is attached to the porous acid stone 22, the acid stone is to play a role of evenly dispersed in the waste slurry by reducing the particles of air injected into the auxiliary pipe, stone or Synthetic resin or metal can be used, and the shape can be variously formed if the role of distributing air evenly is faithfully fulfilled.

In addition, the outer surface of the air inlet pipe 21 of the stirring unit 2 is provided with a motor 5 is in contact, the motor 5 is an acid stool attached to the lower portion by rotating the air inlet pipe about its axis As it rotates, it functions to contain air evenly in the waste slurry.

On the other hand, the coupler 4 is formed with a through-hole 41 is formed through the lower side through which the air injection pipe 21 is inserted from the side in which the transfer pipe 3 is inserted, the air injection pipe is inserted The lower portion has a structure of a bearing 42, and the shape of the through hole 41 may be modified according to the direction in which the transfer pipe 3 and the air injection pipe 21 are coupled to each other.

When a part of the stirring unit 2 of the present invention is operated by inserting the waste slurry into the waste slurry, the air sucked from the air tank or the air suction pipe (pump) passes through the transfer pipe 3 and the air injection pipe 21, It reaches (22), and it passes through a porous acid stone and becomes a small bubble of air, and is injected into the waste slurry.

At this time, by the motor (5) installed on the outer circumferential surface of the air injection pipe 21, the air injection pipe is rotated about its axis, and the mountain stone 22 installed in the lower portion of the air injection pipe is also rotated The waste slurry is mixed with the slurry, and the liquid waste slurry is whirlwind in the form of whirlwind, and the air bubbles emitted from the acid stone are mixed with the waste slurry and stayed for a long time. By increasing the area and time of contact of the waste slurry, the oxidation of the waste slurry proceeds rapidly.

Hereinafter, the embodiment of the performance test of the diffuser according to the present invention.

The mechanism of gas delivery is the simplest and most widely used two-film theory published by Lewis and Whitman.

The bilayer theory is based on the physical model that two membranes exist at the gas-liquid interface as shown in FIG. 4, and there are three mass transfer resistances in gas (oxygen) transfer, Membrane resistance at the gaseous and gas-liquid interface, and the other can be divided into the interface resistance at the gas-liquid interface and the liquid film resistance between the interface and the liquid phase.

The overall oxygen transfer resistance is equal to the sum of these individual resistances, and the relative value of each resistance may vary depending on the composition, density, and gas-liquid contact surface phenomena, but usually the bubble size is small and the gas phase is sufficiently mixed. Therefore, the membrane resistance is ignored compared to other resistances, and the gas-liquid interface resistance is also ignored because the oxygen concentration at the bubble surface and the concentration in the bubble are the same.

Therefore, from the oxygen supply side, the main resistance is the resistance in the liquid film surrounding the bubble, and the total oxygen transfer coefficient (K _L a) can be seen as the oxygen transfer coefficient (k _L a) of the liquid film.

Under turbulent conditions assuming that the resistance of the liquid film limits the oxygen transfer rate, the transfer of oxygen from the gas phase to the liquid phase is a function of the overall mass transfer coefficient and the oxygen deficit, expressed as:

dC / dt = K _L a (C _S -C) (Equation 1)

Integrating Equation 1 gives:

In {(C _S -C _t ) / (C _S -C _O )} =-K _L at (Equation 2)

here

C: DO concentration at time t

K _L a: Overall Mass Transfer Coefficient

C _S : Saturated dissolved oxygen concentration (DO) in water at standard temperature, pressure and salinity

_CO : dissolved oxygen concentration (DO) at time t = 0

C _t : dissolved oxygen concentration (DO) at time t

The overall mass transfer coefficient K _L a can be measured physically by the method described below. Oxygen transfer can be measured by the most common method of determining the transfer efficiency, either by a test tank or by an unsteady reaeration of deoxygenated water in an actual aeration tank.

Experimental apparatus used in this experiment, as shown in Figure 5,

Aeration tank 103, the transfer pipe (3), dissolved oxygen (Dissolved Oxygen) measuring device 106, the stirring unit 2, the aeration tank 103 is an acrylic material of a rectangular shape and the effective capacity is 3L and Three porous diffusing stones 105 are disposed, and the liquid phase in the aeration tank is used in distilled water so that the aeration tank is located in the constant temperature water tank 104 to maintain a constant liquidus temperature.

Air and nitrogen are supplied from the air pump 6 and the nitrogen storage tank, respectively, and the injection amount is controlled by the hydraulic regulator 102 having a capacity of 5 l / min, by the porous diffusion stone 105 installed at the lower portion of the aeration tank 103. The liquid is blown into the liquid phase, and only the air is blown into the liquid phase toward the stirring unit 2 through the acid stone 22, and the dissolved oxygen (DO) measuring unit 106 is installed at a point 2.5 cm below the surface of the liquid phase.

The air diffuser 1 is largely composed of a motor 5, the coupling port 4, the air injection pipe 21 and the acid rock 22, the stirring motor 5 can adjust the stirring speed up to 1000rpm , The air injection pipe 21 is a 3/8 inch SUS tube, 50cm in length and the upper end of the tube can be smoothly rotated by separating the transfer pipe 3 and the air injection pipe 21. The coupling hole 4 to which the bearing 42 was coupled was attached, and the 4 cm length of the lower end of the aeration tank 103 increased the outer diameter of the tube to 15 mm to facilitate the attachment of the mountain stone 22 to the SUS tube. Three acidic stones were attached to each other at 120 ° intervals around the end of the agitating role, and the diameter and capacity of each acidic stone 22 were 2.55 cm and 8.68 cm ^3, respectively.

As shown in FIG. 5, in the performance test of the air diffuser having the integrated air distribution and stirring, first, the air inlet valve 101a of the stirring part is shut off, and the porous diffusion stone 105 installed below the aeration tank 103. Nitrogen gas was blown into the aeration tank to remove dissolved oxygen in the aeration tank, and then the initial concentration (C _O ) of the dissolved oxygen was measured.Then, the air inlet valve 101b at the bottom of the aeration tank was shut off, and then the air inlet valve at the stirring part ( 101a) is opened and air is blown into the aeration tank for a certain time to measure dissolved oxygen concentration (C _t ) according to time, and then the total mass transfer coefficient (K _L a) in relation to dissolved oxygen concentration and time as shown in Equation 2. It can be obtained by calculating

In the performance test of the air dispersing device having a separate air distribution and agitation, first, the air inlet valve 101a of the agitation part is blocked, and then nitrogen gas is blown into the porous diffusion stone 105 installed at the lower part of the aeration tank 103. After removing the dissolved oxygen inside, measure the initial concentration of dissolved oxygen (C _O ), and then blow air into the aeration tank for a certain time to measure the dissolved oxygen concentration (C _t ) according to the time and transfer the overall substance by the above-mentioned method. The coefficient may be calculated.

The main experimental variables and conditions in this experiment are 0.5 ~ 3.0ℓ / min air supply, stirring speed 0 ~ 1000rpm, liquid phase temperature is 20 ~ 40 ℃.

Figure 6 compares the change in the overall material transfer coefficients for the air dispersing unit and the air dispersing unit is integrated with the air distribution and agitation while changing the air supply, the liquid phase temperature and the stirring speed is 20 ℃ and 500rpm, respectively.

As shown in FIG. 6, regardless of the change in the air supply, the total mass transfer coefficient is higher than in the case of the separate type in which the air distribution and agitation are integrated, so that the integrated air diffuser improves the overall material transfer coefficient. It is showing superiority.

The result is that a good gas-liquid contact pattern is maintained and a good swirl flow is formed. The integrated air diffuser is effective for improving the gas-liquid contact frequency and contact efficiency, and the good turnover time can increase the residence time of bubbles. This is because a liquid flow pattern to form a flow occurred.

In addition, Figure 7 compares the change in the overall material transfer coefficient for the air dispersing unit and the air dispersing unit and the air dispersing unit and the integrated dispersing unit while changing the stirring speed, the liquidus temperature is 20 ℃ and the air supply amount 2.0 L / min to be.

As shown, regardless of the stirring speed, the integrated diffuser showed superiority in the overall material transfer coefficient improvement compared to the separate type, and this trend is more pronounced as the stirring speed is increased. This is because the fluidization of the gas promoted the pulverization of the bubbles to increase the contact area between the gas and the liquid, as well as to make the contact frequency between the gas and the liquid more active.

Figure 8 compares the change in the overall material transfer coefficient of the air dispersing unit and the air dispersing unit with the air distribution and agitation while changing the liquid phase temperature, the air supply amount is 2.0 L / min and the stirring speed is 500rpm.

As shown, the overall material transfer coefficient, like the change in the air supply amount and the liquidus temperature, it can be seen that the integrated diffuser has a superior effect on the improvement of the overall material transfer coefficient compared to the separate type regardless of the change in the liquidus temperature.

As can be seen from the above experimental results, it is possible to obtain an apparatus having excellent performance while simplifying the apparatus, and the embodiment according to the present invention is not limited to the above-described one, and it is obvious to those skilled in the art in connection with the present invention. Various alternatives, modifications, and changes can be made within the scope.

The performance comparison between the air distributor and the agitator integrated with the air distribution and agitation for the gas-liquid mass transfer rate was performed based on the air supply, the stirring speed, and the liquidus temperature, which are the key operating factors of the aeration process. According to the research results, the air diffuser with integrated air distribution and agitation showed a more significant effect than the separate type air diffuser in improving the overall material transfer coefficient regardless of the change of operating factors. The gas-liquid contact efficiency seems to be maximized.

Therefore, in view of the above test results, it is possible to provide a simplified diffuser that provides high efficiency while reducing initial investment and operating costs.

Claims (2)

A pump 6 for sucking air from the air tank or the outside; A transfer pipe (3) for transferring the air sucked into the pipe body having one end coupled to the pump; An air injection pipe 21 for injecting air transferred from the transfer pipe into the aeration tank, and a porous acidic stone 22 coupled to the lower portion of the air injection pipe and injecting air passing through the air injection pipe into the aeration tank; A stirring section 2 made up of; A through hole 41 is formed at the side from which the feed pipe 3 is inserted, leading to the bottom into which the air injection pipe is inserted, and the bearing 42 is inserted into the bottom to allow the air injection pipe 21 to rotate. Stirring unit type diffuser device, characterized in that consisting of a sphere (4). The motor (5) according to claim 1, wherein the motor (5) is installed in contact with an outer surface of the air injection pipe (21), is fixed by a support (107), and transmits power so that the air injection pipe can rotate about an axis. Stirring integrated diffuser device, characterized in that is further attached.