KR102458142B1 - Modified Venturi scrubber and method of removing particles using the same - Google Patents

Abstract

The present invention relates to an improved venturi scrubber and a method for removing particles using the same. Specifically, the present invention relates to a venturi scrubber that is an improved Reither venturi scrubber and a method for removing particles using the same, particularly particles including fine dust.

Description

Modified Venturi scrubber and method of removing particles using the same}

The present invention relates to an improved venturi scrubber and a method for removing particles using the same. Specifically, it relates to a REITHER venturi scrubber improved venturi scrubber and a method for removing particles using the same, particularly particles including fine dust.

The scrubber that treats the exhaust gas is a packed tower scrubber, a spray tower scrubber, a cyclone scrubber, a venturi scrubber, an ejector scrubber, a single tower scrubber, depending on the gas treatment method. Bubble cap, Sieve plate), etc.

1 is a schematic diagram of a venturi scrubber according to the prior art. Referring to FIG. 1 , the venturi scrubber is a device for inducing gas/liquid contact by flowing an exhaust gas (Gas _ORI ) to a throat at high speed, and supplying a cleaning solution (Water) thereto. It is a device that speeds up the flow of air, uses the kinetic energy obtained from it, induces atomization of the cleaning liquid (water), and collects gas or dust using the collision effect generated from this flow.

The cleaning liquid (Water) is sprayed through the nozzle to prevent dust from sticking due to the wet/dry area formed very sensitively at the inlet of the venturi. The flow rate of the gas that has passed through the throat is restored to the original flow rate, and most of the harmful gases and dust are removed by the washing liquid (Water). The remaining materials are additionally removed by centrifugal force in the cyclone separator at the rear end.

The venturi scrubber is small in size, but it has the advantage of being able to process a large amount of gas and simultaneously process dust and gas with high efficiency. Although the venturi scrubber is a device that has been widely used for more than 100 years, it has the following problems.

i) High pressure loss requires a lot of operating power cost, and ii) There is a risk of drift when manufacturing with a large capacity. When ultra-fine dust of 1 μm or less is collected, which is a recent problem, a high pressure loss of at least 500 to 800 mmH ₂ O occurs, and accordingly, there is a problem in that the operating cost becomes more excessive. The abrasion of the throat according to the rapid flow rate of 60 to 100 m/sec also becomes more severe.

FIG. 2 is a schematic diagram of a REITHER venturi scrubber that has improved the conventional venturi scrubber (https://altech-group.com/), and FIG. 3 is a cross-sectional view thereof. Rider (REITHER) venturi scrubber is an improvement in the point that the conventional venturi scrubber is not provided with a means for separately adjusting the pressure.

2 and 3, the Rider (REITHER) Venturi scrubber is a lower cylinder (Movable displacer) between two cylinders (Fixed cylinder) while moving up and down by the actuator (Actuator) while reducing the size of the neck (Venturi throat) Adjust. Through this, the damping rate is controlled while controlling the pressure loss and passing flow rate.

The REITHER Venturi scrubber has a shape of three circles in contact with each other, so it is difficult to gradually adjust the opening/closing rate (S) by the movement of the lower cylinder (Movable displacer). Accordingly, when the flow velocity reaches near 50 m/sec, there is a problem in that the vibration suppression efficiency is sharply decreased. In addition, hunting occurs due to particles accumulating between the part where the three inner circles are in contact with each other and the two cylinders (Fixed cylinder) and the tube (Vertical cylinder).

In the case of the Rider Venturi scrubber, the adhesion problem of PbO ₂ has actually been reported, but there is no clear solution to this problem.

As such, the conventional venturi scrubber and the improved REITHER venturi scrubber have limitations in removing ultrafine dust. Moreover, hydrophobic dust having a specific gravity lower than 1 still has a problem in that it cannot be substantially removed.

The present invention is to solve the above problems, and compared to the conventional venturi scrubber or rider venturi scrubber, 1) there is no hunting phenomenon, 2) reducing the pressure loss to reduce the operating cost, 3) low oil It enables stable dust removal even in high temperatures, 4) increases the lifespan of equipment and reduces the inconvenience of cleaning by preventing dust accumulation, and 5) can also remove hydrophobic dust with a specific gravity lower than 1, which is difficult to remove from paintwork, etc. An object of the present invention is to provide a venturi scrubber.

In order to solve the above problems, the present invention provides a gas inlet disposed at the top of the venturi scrubber and injecting exhaust gas, a cleaning liquid injection port disposed at the bottom of the gas inlet and including a nozzle for spraying the cleaning liquid, at the lower end of the cleaning liquid injection port a fixed baffle coupled to the inner periphery of the venturi scrubber tube in a ring shape, disposed at the lower end of the fixed baffle and movable up and down, and the gas and cleaning liquid pass through an empty space with the fixed baffle In the venturi scrubber comprising a displacer forming a throttle,

The fixed baffle provides a venturi scrubber having a left-right symmetrical shape with respect to the center of the venturi scrubber, and an upper portion of the fixed baffle cross-section is inclined downward by 45 degrees or more.

The gas inlet may be in the form of a cyclone through which the exhaust gas is introduced along a tangent to the side of the venturi scrubber.

One side cross-section of the fixed baffle is a triangle, the base of the triangle is coupled to the inner periphery of the venturi scrubber tube, one side of the triangle is inclined downward by 45 degrees or more, the other side of the triangle and the displacer The cross-sections may be parallel to each other.

In a specific form, the fixed baffle is the same as the delta ring used as a gasket in that the cross section is triangular. In the delta ring, the inside of the donut is vertical as the base of the triangle, but in the fixed baffle according to the present invention, the outside of the donut is vertical as the base of the triangle.

The height of the triangle may be 0.2 to 0.45 of the inner diameter of the venturi scrubber, the displacer may be disposed in the center of the venturi scrubber, and the outer diameter of the displacer may be 0.1 to 0.6 of the inner diameter of the venturi scrubber.

The venturi scrubber may have a circular cross-section, and an upper portion of the displacer may have a conical shape. The lower portion of the displacer may have a shape other than a cone. When the cross-section of the venturi scrubber is polygonal, it is obvious that the fixed baffle and the displacer are also deformed according to their shape.

The present invention also provides a method for removing dust and gas from the exhaust gas using the venturi scrubber, wherein the supply volume of the cleaning solution is at least twice the supply volume of the exhaust gas.

The present invention also provides a method for removing dust and gas from the exhaust gas using the venturi scrubber, wherein the flow velocity of the fluid in the venturi scrubber is 60 m/sec or less.

The present invention also provides a method for removing dust and gas from the exhaust gas using the venturi scrubber, wherein the cleaning solution includes a cationic surfactant.

In this case, the concentration of the cationic surfactant in the cleaning solution may be 0.05M or less.

The surfactant should be added in an amount that does not cause phase separation, and should be added at a concentration higher than that capable of generating micelles (CMC or higher) without bubbles.

The present invention changes the throat structure of the Rider Venturi scrubber in contact with the existing three cylinders to a conical shape and changes the gas flowing in from the upper part to a tangential inflow cyclone shape, 1) Particles around the throat Not only does it fundamentally prevent the accumulation of cysts, but it also prevents the hunting phenomenon by gently adjusting the spacing of the throat. Due to the conical inclined surface as described above, the venturi effect of the device according to the present invention is increased by about 5% compared to the conventional device. 2) In the present invention, the pressure loss is lowered by the cone shape, which reduces the operating cost and 3) the vibration suppression efficiency does not drop suddenly, enabling stable vibration suppression even at low flow rates. 4) The present invention also increases the life of the equipment as all equipment is placed in the tube of the scrubber without a fixed cylinder protruding to the outside like the conventional Rider Venturi scrubber, Thus, the frequent cleaning cycle was extended by preventing the accumulation of dust on the wall of the existing scrubber. PbO ₂ and the like are not only deposited in the conventional scrubber, but also continuously grow to decrease the efficiency of the device, so frequent maintenance is required. In addition, a small amount of grown dust is intermittently desorbed and causes hunting of the scrubber, but the present invention can fundamentally block this problem. 5) On the other hand, hydrophobic dust having a specific gravity lower than 1 generated in paint coating, etc., which was difficult to remove conventionally, was removed using a cationic surfactant.

As described above, the improved venturi scrubber according to the present invention and a method for removing particles using the same have higher vibration removal efficiency, energy consumption, driving safety, maintenance cycle, and specific gravity than the conventional venturi scrubber or rider venturi scrubber. It shows a very excellent effect in removing low hydrophobic dust, etc.

1 is a schematic diagram of a venturi scrubber according to the prior art.
Figure 2 is a schematic diagram of a Rider (REITHER) venturi scrubber improved from the conventional venturi scrubber.
3 is a cross-sectional view of a Rider (REITHER) venturi scrubber improved from the conventional venturi scrubber.
4 is a cross-sectional view of a venturi scrubber according to the present invention.
5 is a schematic view of the gas inlet of the upper portion of the venturi scrubber according to the present invention.
6 is an experimental result for the pressure loss according to the flow rate.
7 is an experimental result on the vibration damping efficiency according to the flow rate.

Hereinafter, embodiments in which those skilled in the art can easily practice the present invention will be described in detail with reference to the accompanying drawings. However, in the detailed description of the operating principle of the preferred embodiment of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. Throughout the specification, when it is said that a part is connected to another part, it includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of a certain component does not exclude other components unless otherwise stated, but means that other components may be further included.

4 is a cross-sectional view of a venturi scrubber according to the present invention, and FIG. 5 is a schematic view of an upper gas inlet of the venturi scrubber according to the present invention.

4 and 5, the present invention will be described. The present invention is disposed at the top of the venturi scrubber and includes a gas inlet through which an exhaust gas (Gas _ORI ) is injected, a cleaning liquid injection port disposed at the lower end of the gas inlet and including a nozzle for spraying the cleaning liquid, and a lower end of the cleaning liquid injection port. a fixed baffle coupled in a ring shape to the inner periphery of the venturi scrubber tube, disposed at the lower end of the fixed baffle and movable up and down, and the fixed baffle and In the venturi scrubber comprising a displacer (Movable displacer) forming a throttle (Venturi throat) through which the gas and the cleaning liquid pass through the empty space of the

The fixed baffle (Fixed baffle) is symmetrical with respect to the center of the venturi scrubber, and an upper portion of the cross-section of the fixed baffle is a straight venturi scrubber inclined downward by 45 degrees or more. That is, the angle of θ _F1 or θ _F2 in FIG. 4 is 45 degrees or more.

The displacer is movable up and down by an actuator.

The gas inlet may be in the form of a cyclone through which exhaust gas (Gas _ORI ) is introduced along a tangent line of the side of the venturi scrubber (see FIG. 5).

A cross section of one side of the fixed baffle is a triangle, a base of the triangle is coupled to an inner periphery of the venturi scrubber tube (Vertical cylinder), and one side of the triangle is downward (angle of θ _F1 ) 45 degrees It is inclined more than, and the other side of the triangle and the cross section of the displacer may be parallel to each other. In the case of FIG. 4 , the angles of θ _D1 and θ _D2 are the same. Accordingly, the size S of the throttle (Venturi throat) is constantly changed.

In a specific form, the fixed baffle is the same as the delta ring used as a gasket in that the cross section is triangular. In the delta ring, the inside of the donut is vertical as the base of the triangle, but in the fixed baffle according to the present invention, the outside of the donut is vertical as the base of the triangle.

The height (D _F ) of the triangle is 0.2 to 0.45 of the inner diameter of the venturi scrubber, the movable displacer is disposed in the center of the venturi scrubber, and the outer diameter (D _M ) of the displacer is the venturi It may be 0.1 to 0.6 of the inner diameter of the two-way scrubber.

The venturi scrubber may have a circular cross-section, and an upper portion of the movable displacer may have a conical shape. The lower portion of the displacer (Movable displacer) may have a shape other than a cone. When the cross-section of the venturi scrubber is polygonal, it is obvious that the fixed baffle and the movable displacer are also deformed according to their shape.

The exhaust gas supplied to the upper part (Gas _ORI ) is discharged to the outside through the scrubber (Gas _CLE ).

(Example 1)

In order to measure the pressure loss and vibration damping rate when the venturi scrubber according to the present invention is used, hydrophilic wood flour was used as model particles. The particles are hydrophilic wood powder and have a particle diameter of 1 μm or less, and a density of 0.5 g/m 3 .

The venturi scrubber according to Example 1 has a cylindrical shape and has an inner diameter of D. The fixed baffle is in the form of a ring, and the cross section of the ring is an isosceles triangle. The base of the isosceles triangle is coupled to the inner periphery of the venturi scrubber tube. The interior angles of the isosceles triangle are 45 degrees, 90 degrees, and 45 degrees, respectively, and one side of the isosceles triangle is inclined at 45 degrees downward. The height of an isosceles triangle constituting the cross section is 0.4D. The displacer is a rhombus in cross section and has a shape with two cones attached. The displacer is disposed in the center of the venturi scrubber, and the outer diameter of the displacer, that is, the largest part of the cone is 0.5D of the inner diameter of the venturi scrubber. Since the height of the displacer is adjusted vertically, it is possible to form a throttle through which the gas and the cleaning liquid pass through an empty space with the fixed baffle. As the washing solution, only water was used.

In the case of Example 1, the supply volume of the exhaust gas (G) including the cleaning liquid (L) and the wood powder L/G = 1, and the injection pressure of the exhaust gas is 3kgf/cm2. In the case of Example 1, the exhaust gas was supplied from the top of the venturi scrubber, and was not supplied in the form of a cyclone.

(Example 2)

It is the same as in Example 1, except that the supply volume L/G = 3 of the cleaning liquid (L) and the exhaust gas (G) containing the wood powder.

(Example 3)

It is the same as in Example 1, except that the exhaust gas was supplied in the form of a cyclone and a cationic surfactant was included in the cleaning solution. The cationic surfactant was added at 0.05M.

(Comparative example)

Comparative Example is a conventional venturi scrubber, in which there is no fixed baffle, displacer, and cyclone for exhaust gas injection according to the present invention. The venturi scrubber according to the comparative example and the venturi scrubber according to the embodiment have the same cylindrical shape and the same inner diameter. The venturi scrubber according to the comparative example has a throttle fixed to the central part.

In the case of the comparative example, the supply volume of the cleaning liquid (L) and the exhaust gas (G) containing the wood powder L/G = 1, and the injection pressure is 1kgf/cm2.

Pressure loss (mmH ₂ O) flow rate
(m/sec) 10 20 30 40 50 60 70 80 90 100 comparative example 10 30 70 125 200 280 380 500 620 750 Example 1 10 30 70 125 200 280 380 500 620 750 Example 2 15 60 130 200 - - - - - - Example 3 65 120 - - - - - - - -

Vibration suppression efficiency (%) flux
(m/sec) 10 20 30 40 50 60 70 80 90 100 comparative example 0 0 10 30 75 80 90 95 98 99 Example 1 80 85 90 95 98 99 - - - - Example 2 90 95 99 99 - - - - - - Example 3 95 99 - - - - - - - -

Table 1 shows the pressure loss (mmH ₂ O) according to the flow rate for Examples 1 to 3 and Comparative Examples according to the present invention, and Table 2 shows the vibration damping efficiency according to the flow rate. In Tables 1 and 2, the flow rate is a value that changes as the size of the throttle is adjusted under a constant injection pressure. 6 and 7 are graphs of pressure loss and vibration suppression efficiency according to flow rate, respectively.

Referring to Tables 1 and 2 and FIGS. 6 and 7, the conventional venturi scrubber (Comparative Example, Comp. Ex.) requires a flow rate of 100 m/sec and a pressure loss of 750 mmH ₂ O to obtain a dust removal efficiency of 99%. . That is, in the case of the conventional venturi scrubber, the desired efficiency can be obtained only when the flow rate is increased by making the size of the throttle very small, and in this case, a lot of energy is required due to the pressure loss.

Referring to Examples 1 and 2, it can be seen that the same vibration suppression rate as in Comparative Examples can be achieved even at a flow rate of 30 to 60 m/sec and a pressure loss of 300 mmH ₂ O or less as a result of adjusting the amount of cleaning liquid and the injection pressure. 6 , Examples 2 and 3 had an efficiency of 99% when the flow rate was 40 m/sec, and no additional pressure loss was measured.

On the other hand, in the case of the comparative example, the vibration damping rate is rapidly decreasing in the flow velocity of 40 to 50 m/sec and the pressure loss of 200 mmH ₂ O region, which is analyzed to be due to hunting.

In order to obtain a vibration suppression rate of 99% using the conventional venturi scrubber, the flow velocity at the throttle portion should be rapidly increased to reach 100 m/sec. At this time, the washing solution is crushed to a diameter of 50㎛. In the case of Example 3 in which the exhaust gas was injected in the form of a cyclone, the pressure of the cleaning solution increased at a very low flow rate of 20 m/sec, and at this time, it is predicted that the cleaning solution would be crushed to a size of 10 μm or less. This is analyzed as following a tangential inflow cyclone. The faster the flow rate is because the throttle size is small. The actual amount of cleaning liquid is rather larger when the flow rate is low. In the case of Example 3, since the particle size is 1/5 and the flow rate is about 5 times higher, the contact area of the cleaning solution is substantially increased by about 100 times compared to the comparative example, and thus a stable vibration removal rate can be maintained at a low flow rate.

The venturi scrubber according to the present invention does not have a space where dust can be deposited, unlike the rider venturi scrubber shown in FIG. 3 . By tilting the upper part of the fixed baffle downward by more than 45 degrees, not only dust cannot be deposited, but it seems that the accumulated dust is rather removed when the exhaust gas is supplied through a tangential inflow cyclone. On the other hand, by supplying the exhaust gas to the tangential inflow cyclone, particles of 10 μm or larger are removed and the fine particles are coarsened, and the efficiency can be further increased due to the impregnation of hydrophobic particles.

It can be seen that the venturi scrubber according to the prior art requires a high flow rate to maintain a high vibration damping rate, and at the same time has a large pressure loss. In the case of the Rider Venturi scrubber, it has been improved in a form that can control the flow rate, but it is difficult to operate stably because the vibration suppression rate is sharply lowered by hunting near the flow rate of 40 to 50 m/sec.

According to the present invention, the amount of cleaning solution (L/G) can be increased up to three times compared to the conventional one, and by adjusting the injection pressure to 0.5 to 3 kgf/cm2, it is possible to increase the vibration removal rate while reducing operating costs and to operate it stably do.

In addition, in the case of hydrophobic dust having a specific gravity lower than 1 generated in paint painting, which has been difficult to solve in the prior art, a cationic surfactant was added and treated. It is preferable to maintain the concentration of the cationic surfactant to such a degree that one phase is maintained so that no phase separation occurs in the washing solution. If the concentration of surfactants is high, they may re-scatter as particles.

Claims (9)

a gas inlet disposed at the top of the venturi scrubber and into which exhaust gas is injected;
a cleaning liquid injection port disposed at a lower end of the gas inlet and including a nozzle for spraying the cleaning liquid;
a fixed baffle disposed at the lower end of the cleaning solution injection port and coupled to the inner periphery of the venturi scrubber tube in a ring shape;
a displacer disposed at the lower end of the fixed baffle, movable up and down, and forming a throttle through which the gas and the cleaning liquid pass through an empty space with the fixed baffle;
In the venturi scrubber comprising a,
The fixed baffle is symmetrical to the left and right with respect to the center of the venturi scrubber, and the upper part of the cross-section of the fixed baffle is a straight line inclined downward by 45 degrees or more,
One side cross-section of the fixed baffle is a triangle, and the base of the triangle is coupled to the inner periphery of the venturi scrubber tube,
One side of the triangle is inclined downward by 45 degrees or more,
The other side of the triangle and the cross section of the displacer are parallel to each other venturi scrubber. According to claim 1,
The gas inlet is a venturi scrubber in the form of a cyclone in which the exhaust gas flows along a tangent to the side of the venturi scrubber. delete According to claim 1,
The height of the triangle is 0.2 to 0.45 of the inner diameter of the venturi scrubber,
The displacer is disposed in the center of the venturi scrubber, and the outer diameter of the displacer is 0.1 to 0.6 of the inner diameter of the venturi scrubber venturi scrubber. According to claim 1,
The venturi scrubber has a circular cross-section,
The upper portion of the displacer is a venturi scrubber in the form of a cone. [Claim 6] In the method of removing dust and gas from the exhaust gas using the venturi scrubber according to any one of claims 1, 2, 4, and 5,
The supply volume of the cleaning liquid is at least twice the volume of the exhaust gas supply. [Claim 6] In the method of removing dust and gas from the exhaust gas using the venturi scrubber according to any one of claims 1, 2, 4, and 5,
The flow velocity of the fluid in the venturi scrubber is 60m/sec or less. [Claim 6] In the method of removing dust and gas from the exhaust gas using the venturi scrubber according to any one of claims 1, 2, 4, and 5,
The cleaning solution comprises a cationic surfactant. 9. The method of claim 8,
The concentration of the cationic surfactant in the cleaning solution is 0.05M or less.

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