KR200296868Y1 - Structure for UV lamp in water and wastewater treatment system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an ultraviolet lamp for treatment water disinfection in water and sewage treatment facilities.

2. The technical problem the invention is trying to solve

To increase the disinfection efficiency of UV lamps.

3. Summary of solution of design

The subject matter of the present invention is that the ultraviolet lamp is installed in a rack having a rectangular parallelepiped frame that is installed in the treatment tank of the reactor in the sewage and water treatment system for sterilization using an ultraviolet lamp, The ultraviolet lamp is installed inclined at a predetermined angle in the flow direction of the reaction tank treatment water, the first ultraviolet lamp installed at an angle from the lower end to the upper end; A second ultraviolet lamp installed at an upper end inclined at the predetermined angle to cross the first ultraviolet lamp; And a ballast installed at an upper end of the rack to supply power to the first and second ultraviolet lamps.

4. Important uses of the devise

Used for water and sewage treatment facilities.

Description

Structure for UV lamp installation in water and sewage treatment system

The present invention relates to ultraviolet (Ultraviolet ray) disinfection, and more particularly to a microbial disinfection process using ultraviolet light for disinfection of water treatment facilities, such as water treatment plants and sewage treatment plants.

Conventionally, microorganisms are oxidized by injecting chlorine-based compounds such as sodium hypochlorite and chlorine dioxide or ozone to oxidize cellular components of microorganisms based on strong oxidizing power, and by intensively destroying the molecular structure of thymine in the base of DNA using ultraviolet rays. A technique for disinfecting was developed and used. In the case of water treatment, residual chlorine was maintained at 2mg / L mainly using chlorine compounds to maintain disinfection effect to the end of water supply. However, in sewage treatment, it was discharged to the stream without additional disinfection treatment.

However, since the disinfection process is required to add E. coli group to the water quality control items in 2003, the disinfection process using ultraviolet rays will be installed in sewage treatment effluent. Chlorine-based compounds need additional dechlorination process due to their residuals. In addition, ozone requires relatively expensive operating costs, and thus, many ultraviolet disinfection processes will be installed.

Factors affecting microorganisms in the UV sterilization system include the intensity of ultraviolet rays emitted from the UV lamp and the contact time between the microorganisms and the UV rays. Ultraviolet disinfection is recognized as a primary reaction that is independent of the type of microorganism and proportional to the intensity of the ultraviolet. (Water Research, 19, 1985, International Association Water Quality, Qualls, RG, and Johnson, JD, Modeling and Efficiency of Ultraviolet Disinfection Systems, 1039; J. Water Pollut.Control Fed., 59, 1987, Water Pollut.Control Fed ., Scheible, OK, Development of a Rationally Based Design Protocol for the UV Light Disinfection Process, 25; J. Water Pollut. Control Fed., 56, 1984, Water Pollut.Control Fed., Severin, BF, Suidan, MT, Rittmann, BE, and Engelbrecht, RS, Inactivation kinetics in a Flow-Through UV Reactor, 164).

Therefore, the microorganism to be sterilized decreases exponentially as the irradiation amount of ultraviolet rays (UV dosage: hereinafter referred to as 'ultraviolet radiation dose') increases and the irradiation dose of ultraviolet rays is expressed by the following equation.

UV dose = ultraviolet intensity (I) × contact time (t) where ultraviolet intensity is a function of time, not a constant, is expressed as In the above equation, 'D' represents an ultraviolet irradiation amount, and 'I' represents an ultraviolet intensity.

In the UV disinfection process, the intensity of the UV lamp is maintained at almost constant value by the lamp manufacturer and the voltage supplied to the lamp. Therefore, the contact time should be increased as much as possible to increase the UV irradiation amount. In particular, even after thymine is stuck to cytosine in the microbial DNA and replication becomes impossible, even if a certain wavelength of visible light is exposed, recovery enzyme is secreted and damaged DNA is recovered so that the effect of disinfection is lost. And the appropriate dose of UV radiation depends on the microbial species. Existing technologies have been used to install UV lamps in parallel with the influent flow direction to achieve disinfection by exposing microorganisms in the influent to ultraviolet light. This is a method for maintaining the plug flow in the disinfection process to maintain the reaction between the microorganism and the ultraviolet rays as efficiently as possible to confirm that the plug flow is generated by the actual hydraulic measurement (J. Environ. Eng., 121, 1995, American Society of Civil Engineering, Blatchley, ER III, Wood, WL, and Schuerch, p., UV Pilot Testing: Intensity Distribution and Hydrodynamics, 3).

However, such a UV system has a disadvantage in that a wider boundary layer is formed on the surface of the UV lamp to cause shear stress, so that most of the inflow water passes at a high velocity away from the surface of the UV lamp. In this case, the thickening of the boundary layer was further enhanced (J. Environ. Eng., 123, 1997, American Society of Civil Engneering, Iranpour, R., UV Pilot Testing: Intensity Distribution and Hydrodynamics, 5).

Ultraviolet rays emitted from UV lamps are affected by the permeability of the target medium and the presence or absence of impurities, and the intensity of UV rays is high as the transmittance is high and no impurities are maintained and propagated in all directions. Therefore, when ultraviolet rays are radiated to the same medium, the higher intensity ultraviolet rays are irradiated closer to the ultraviolet lamps, so that a boundary layer is formed around the ultraviolet lamps, so that most of the inflow water is far from the ultraviolet lamps. In addition, when the inflow water flows through the disinfection reactor, the effective cross-sectional area of the reactor decreases depending on the thickness of the boundary layer in addition to the area occupied by the UV lamp, and the actual reaction time of the reactor is inversely proportional to the thickness of the boundary layer (Water Environment Research, 71, 1). , 1999, Water Environment Federation, Iranpour, R., Garnas, G., Moghaddam, O., Taebi, A., Hydraulic Effects on Ultraviolet Disinfection: Modification of Reactor Design, 114).

In sewage treatment plants, the microorganisms to be disinfected are more likely to floc and adhere to suspended solids than are single individuals. Therefore, if laminar flow is formed on the surface of high intensity UV lamp for the influent with a lot of suspended solids, the disinfection process is performed with little rotation of the floc, so the microorganisms in the floc are not evenly irradiated with UV rays. The effect is reduced. To compensate for this, a process of disinfecting by installing UV lamps perpendicular to the influent flow direction has been developed. When the UV lamps are arranged vertically, it is possible to suppress the laminar flow formation on the surface of the UV lamps and to reduce the thickness of the boundary layer to the minimum, thereby increasing the effective cross-sectional area of the disinfection tank, but they are arranged perpendicular to the inflow flow direction. As a result, the contact time passing through the UV lamp is significantly reduced compared to the case in which the influent flows in parallel with the influent flow direction.

In addition, when the UV lamp is arranged horizontally with the flow direction of the inflow water, the flow rate is increased and the disinfection efficiency is lowered.

In order to solve the above problems, an object of the present invention is to minimize the formation of the boundary layer of the UV lamp surface to suppress laminar flow, to generate turbulence around the lamp so that the ultraviolet light is evenly distributed to the target microorganisms, and the effective cross-sectional area is as wide as possible It is to provide a method for disinfecting microorganisms more effectively by designing a system so that ultraviolet light is irradiated for a long time by securing.

1 is a simplified side view showing the installation of an ultraviolet lamp according to an embodiment of the present invention.

2 is a view for explaining the radiation dose of the ultraviolet lamp according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: first ultraviolet lamp 20: second ultraviolet lamp

30: ballast 40: rack

The present invention for achieving the above object, in the ultraviolet lamp installation structure of the sewage and water treatment system using the ultraviolet lamp sterilization, rack 40 having a rectangular parallelepiped frame that is installed submerged in the treated water of the reaction tank The ultraviolet lamp is installed in the, the ultraviolet lamp is installed inclined at a predetermined angle in the flow direction of the reaction tank treatment water, the first ultraviolet lamp installed at a predetermined angle from the lower end to the upper end; A second ultraviolet lamp installed at an upper end inclined at the predetermined angle to cross the first ultraviolet lamp; And a ballast installed at an upper end of the rack 40 to supply power to the first and second ultraviolet lamps.

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

1 is a simplified side view showing the installation of an ultraviolet lamp according to an embodiment of the present invention, Figure 2 is a view for explaining the radiation dose of the ultraviolet lamp according to an embodiment of the present invention.

Unlike the prior art, the array of ultraviolet lamps 10 and 20 is inclined at a predetermined angle without being installed in parallel with the flow direction of the inflow water to disinfect. Since the amount of ultraviolet radiation is proportional to the intensity and contact time of the ultraviolet lamps 10 and 20, when the lamp is inclined in the inflow direction, the ultraviolet light intensity of the microorganisms sterilized at the same distance from the ultraviolet lamps 10 and 20 is the same. The effect of increasing the time and the contact time with the UV lamp is also increased compared to the conventional vertical lamp.

That is, as shown in Fig. 2, the part that approaches the UV lamp, ② the part that passes the surface of the UV lamp, ③ the part that passes the UV lamp surface only when tilted at a predetermined angle, and ④ the part away from the UV lamp The ultraviolet intensity irradiated from the ultraviolet lamp is expressed by the following equation according to Lambert-Beer's law.

In the above equation, 'I _out ' represents ultraviolet intensity at a distance x apart,

'I _in ' represents the intensity of ultraviolet rays on the surface of the ultraviolet lamps 10 and 20,

'k' represents proportional constant,

'x' represents a distance away from the ultraviolet lamps 10 and 20.

In the above equation, it can be seen that the UV intensity gradually weakens due to absorption, scattering, and reflection by an intermediate medium as the UV intensity increases from the UV lamps 10 and 20.

Based on the above equation, ① intensity, contact time and dosage when approaching the ultraviolet lamps 10 and 20 at a distance X away from the ultraviolet lamps 10 and 20 are expressed by the following equation.

In the above equation, 'I ₁ ' represents UV intensity at a distance separated by x when UV lamps 10 and 20 are installed perpendicular to the inflow direction, and 'I ₂ ' is inclined by θ in the inflow direction. When the fork ultraviolet lamps 10 and 20 are installed, the UV intensity at a distance separated by x is represented. 'I _o ' represents the ultraviolet intensity at the surface of the UV lamps 10 and 20, and 'D ₁ ' represents the influent water. When the ultraviolet lamps 10 and 20 are installed perpendicular to the flow direction, the ultraviolet irradiation amount is indicated, and 'D ₂ ' indicates the ultraviolet irradiation dose when the ultraviolet lamps 10 and 20 are installed to be inclined by θ in the inflow direction. 'k' represents the proportionality constant, 'x' represents the distance away from the UV lamps 10 and 20 in the direction of the influent flow, so | x | is applied, and 'v' represents the flow rate. When tilting (10, 20) for installation 0 ^o <θ <90 ^o so 0 <sin θ <1 is the dosage it can be seen that the increased .② ultraviolet lamp (10, 20) intensity, the contact time and the dosage of the portion that passes through the surface is expressed by the following equation.

'D' in the above equation represents the diameter of the ultraviolet lamp (10, 20).

③ When passing the surface of the UV lamps 10 and 20 only when the predetermined angle is inclined, the intensity, contact time and dosage when the UV lamps 10 and 20 are separated from the UV lamps 10 and 20 by a certain distance X. Is expressed by the following equation.

When the UV lamps 10 and 20 are installed at an inclined angle, since 0 ^o <θ <90 ^o , the dosage is increased to 0 <sinθ <1.

④ Intensity, contact time and dosage in the part far away from UV lamp are expressed by the following formula.

When the UV lamps 10 and 20 are installed at an inclined angle, since 0 ^o <θ <90 ^o , the dosage is increased to 0 <sinθ <1.

Therefore, the difference in the amount of ultraviolet radiation that affects microbial disinfection is as much as the dose obtained in each section and can be expressed as follows.

Therefore, when the UV lamps 10 and 20 are installed at angles in which the value of the above equation becomes the maximum value in consideration of the diameter and the flow rate of the lamp, there is an advantage that an optimum disinfection efficiency can be obtained.

Meanwhile, as shown in FIG. 1, the ultraviolet lamps 10 and 20 are fixed in the racks 40 and racks so that the racks 40 are vertically lifted, unlike the operation of the reactor when the lamp is broken and the lamps are replaced. There is an advantage that the lamp can be easily replaced, and the ballast 30 is installed on the rack 40 so that a separate ballast 30 becomes unnecessary, and thus the operation and maintenance of the ballast 30 is performed at the site where the sterilization process is performed. Is possible.

As described above, the present invention is installed by tilting the UV disinfection lamp at a predetermined angle in the flow direction of the inflow water, thereby minimizing the formation of boundary layers on the surfaces of the UV lamps 10 and 20 to suppress laminar flow and generate turbulence around the lamp. Ultraviolet rays are uniformly irradiated to the target microorganisms, and the effective cross-sectional area is secured to the widest possible, and thus ultraviolet rays are radiated for a long time.

Claims (2)

In the structure of the installation of the ultraviolet lamps 10, 20 of the constant and sewage treatment system for sterilization using the ultraviolet lamp, The ultraviolet lamp is installed in a rack 40 having a rectangular parallelepiped frame that is immersed in the treated water of the reactor, and the ultraviolet lamps 10 and 20 are inclined at a predetermined angle in the flow direction of the reactor treated water. First ultraviolet lamps 10 and 20 installed at an angle from a lower end to an upper end; A second ultraviolet lamp (10, 20) installed at an angle from the upper end to the predetermined angle so as to intersect with the first ultraviolet lamp (10, 20); And, UV lamp installation structure in the constant and sewage treatment system, characterized in that provided on the top of the rack 40 is provided with a ballast 30 for supplying power to the first and second ultraviolet lamps (10, 20) . The method according to claim 1, The predetermined angle is an ultraviolet lamp installation structure in a constant and sewage treatment system, characterized in that the angle to the maximum value of the following equation. D ₁ : UV irradiation dose when UV lamp is installed perpendicular to the influent flow direction D ₂ : UV irradiation amount when UV lamps 10 and 20 are installed inclined by θ in the influent flow direction v: flow rate k: proportionality constant d: diameter of ultraviolet lamps 10 and 20