CN104815769A - Hydraulic jet air cyclone - Google Patents

Abstract

The invention discloses a hydro-jet air cyclone, which comprises an air cyclone and a hydro-jet atomization chamber. Out of the cyclone cylinder, the lower end is lower than the lower end of the hydraulic jet atomization chamber. The cyclone cylinder is provided with a swirl port, and there is a cylindrical outer jacket on the periphery of the upper part of the cyclone cylinder. The outer wall of the cyclone cylinder is connected to form a hydraulic jet atomization chamber. The outer wall of this part of the cyclone cylinder connected to it has a number of nozzle holes from top to bottom. The upper part of the hydrojet atomization chamber is equipped with Liquid port, the diameter D _x of the central exhaust pipe is 0.5d ~ 0.6d mm; the insertion depth S of the central exhaust pipe is 0.5H ~ 0.75H mm; multiple nozzle holes are arranged in a square array on the cylinder body On the outer wall, and the length h of the spray hole area is 0.6S-1S mm. The invention can realize high-efficiency gas-liquid mass transfer.

Description

Hydro jet air cyclone

technical field

The invention belongs to the technical field of chemical engineering, and in particular relates to a hydrojet air cyclone.

Background technique

Traditional gas-liquid mass transfer equipment mainly includes packed towers, plate towers and spray towers. The liquid phase flows from top to bottom under the action of gravity field, and the gas phase flows from bottom to top. Gas-liquid mass transfer occurs. However, due to the weak gravity field, the flow rate of the liquid film is low, the thickness is large, the mass transfer efficiency of the liquid film is low, and the air resistance is also high, which makes the equipment bulky, material consumption, high investment, and high operating costs.

Chinese patent document CN 101147894 B discloses a hydro-jet air cyclone separator, which mainly includes an outer main cylinder 7 and a spray hole 2 on it, a waste water jacket, a hydro-jet atomization chamber 6, and a central exhaust pipe 4 , Air inlet pipe 3, liquid inlet pipe 5 and waste water outlet 8. This patent is a new type of mass transfer equipment that uses liquid jet and gas swirling hypergravity coupling field to strengthen the gas-liquid mass transfer process. It has the advantages of simple equipment structure, high mass transfer efficiency, wide range of wastewater adaptation, and less air consumption. It has been successfully applied in the treatment of ammonia nitrogen wastewater, simultaneous removal of COD, ammonia nitrogen and total phosphorus in pig farm wastewater, flue gas desulfurization and _SO2 reduction treatment of hexavalent chromium, etc., and achieved good results. However, there are still unreasonable places in the design of the above parts, which need to be improved.

Contents of the invention

The object of the present invention is to provide a hydrojet air cyclone capable of realizing high-efficiency gas-liquid mass transfer.

The hydro-jet air cyclone of the present invention includes an air cyclone and a hydro-jet atomization chamber, the air cyclone is composed of a central exhaust pipe and a cyclone cylinder set, and the upper end of the central exhaust pipe protrudes Outside the cyclone cylinder, the lower end is lower than the lower end of the hydraulic jet atomization chamber. The cyclone cylinder is provided with a swirl port, and the compressed gas is input into the cyclone cylinder through the swirl port, and the compressed gas is in the cyclone. The high-speed rotation in the cylinder body forms a gas swirl field. There is a cylindrical outer jacket on the periphery of the upper part of the cyclone cylinder, which is connected with the outer wall of the cyclone cylinder to form a hydraulic jet atomization chamber. The part connected to it The outer wall of the cyclone cylinder is provided with a plurality of spray holes from top to bottom, and the upper part of the hydrojet atomization chamber is provided with a liquid inlet, and the diameter D _x of the central exhaust pipe is 0.5d to 0.6d mm; The insertion depth S of the central exhaust pipe is 0.5H-0.75H mm; multiple nozzle holes are arranged in a square array on the outer wall of the cylinder, and the length h of the nozzle hole area is 0.6S-1S mm.

The nozzle hole is a circular hole, its diameter d _h is 0.028d-0.05d mm, and the distance l _h between the nozzle holes is 0.15d-0.30d mm.

The swirl port is arranged on the upper part of the cylinder body, and the mouth of the swirl port is rectangular, its length b is 0.4d-0.5d mm, and its width a is 0.2d-0.3d mm.

The cyclone cylinder is composed of a cylindrical section cylinder on the upper part and a conical section cylinder formed by gradually reducing the inner diameter of the lower part; the inner diameter D of the cylinder section cylinder is d mm; the total diameter of the cyclone cylinder is The length H is 4d-5d mm; the length Hc of the cone section is 2d- _2.5d mm.

The lower end of the cylindrical body of the conical section has an underflow opening, the diameter D _d of the underflow opening is 0.3d-0.5d mm, and a valve is arranged at the underflow opening.

The gap _l0 between the central exhaust pipe and the cylinder body of the cylindrical section is 0.2-0.25d mm.

The inner diameter _D0 of the cylindrical outer jacket is d+40˜d+60mm.

The present invention has the following advantages:

(1) By rationally designing the diameter, insertion depth and nozzle area length of the central exhaust pipe, the present invention has the highest energy efficiency compared with the prior art, that is, the deamination efficiency per unit pressure drop is higher;

(2) The nozzle holes are designed as a circle, and their arrangement is designed as a square. Compared with other discharge methods, the square arrangement is beneficial to increase the probability of collision and atomization between the swirling gas and the liquid jet column, and the gas-liquid interaction is more intense, so that the cyclone has a higher gas-liquid mass transfer efficiency;

(3) The separation space of the cyclone is designed as a column-cone combination type. Since the cyclone separation space of the column-cone combination type cyclone narrows, the gas tangential velocity of the cyclone increases, the gas-liquid coupling effect is enhanced, and the mass transfer The efficiency becomes higher; at the same time, the inner diameter and length of the cylindrical section and the conical section are reasonably designed. High gas-liquid mass transfer efficiency;

(4) By reasonably setting the diameter of the nozzle hole and the distance between the nozzle holes, the cyclone has a higher gas-liquid mass transfer efficiency.

Description of drawings

Fig. 1 is the structural representation of prior art;

Fig. 2 is a structural representation of the present invention;

Fig. 3 is the top view of the present invention;

Fig. 4 is the arrangement diagram of nozzle holes in Fig. 1;

Fig. 5 is the comparison chart of deammonization mass transfer efficiency of two kinds of cyclones of column-cone combined type (a) and columnar (b);

Fig. 6 is a comparison diagram of the influence of central exhaust pipe diameter (a) and insertion depth (b) on the mass transfer efficiency per unit pressure drop of hydrojet air cyclone deamination;

Fig. 7 is a comparison diagram of the effect of the arrangement of nozzle holes on the mass transfer efficiency of hydrojet air cyclone deamination;

Fig. 8 is a comparison diagram of the influence of the nozzle hole spacing on the deammonization mass transfer efficiency of the hydrojet air cyclone;

Fig. 9 is a comparison diagram of the influence of nozzle hole diameter on the mass transfer efficiency of cyclone deamination;

Fig. 10 is the connection schematic diagram of hydrojet air cyclone structure and experimental device;

Fig. 11 is a schematic diagram of the variation of reduction and removal rate of hexavalent chromium after the present invention is used for the treatment of Cr(Ⅵ)-containing wastewater;

Fig. 12 is a schematic structural diagram of another embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

Embodiment one

The hydrojet air cyclone shown in Figure 2 and Figure 3 includes an air cyclone and a hydrojet atomization chamber 6, the air cyclone is composed of a central exhaust pipe 4 and a cyclone cylinder 1 set, the center The upper end of the exhaust pipe 4 protrudes from the cyclone cylinder 1, and the lower end is lower than the lower end of the hydraulic spray atomization chamber 6. The cyclone cylinder 1 is provided with a swirl port 11, through which the swirl port 11 Compressed gas is input into the cyclone cylinder 1, and the compressed gas rotates at high speed in the cyclone cylinder 1 to form a gas swirl field. There is a cylindrical outer jacket 9 on the periphery of the upper part of the cyclone cylinder 1, and The outer wall of the cyclone cylinder 1 is connected to form a hydraulic jet atomization chamber 6, and the outer wall of the part of the cyclone cylinder 1 connected to it is provided with a plurality of spray holes 2 from top to bottom, and the hydraulic jet atomization chamber 6 The upper part is provided with a liquid inlet 10 .

As shown in FIG. 2 , the cyclone body 1 is composed of a cylindrical body 1 a and a conical body 1 b whose inner diameter gradually decreases. The inner diameter D of the cylindrical body 1 a is d mm. The total length H of the cyclone cylinder 1 is 4d-5d mm. The length Hc of the conical section cylinder body 1b is 2d- _2.5d mm. Figure 5 is a comparison chart of the deamination mass transfer efficiency of the column-cone combination type (a) and the column-shaped (b) cyclone, from which it can be concluded that the separation space of the cyclone is designed as a column cone When combined, the cyclone has better gas-liquid mass transfer efficiency.

As shown in FIG. 2 , the inner diameter D ₀ of the cylindrical outer jacket 9 is d+40˜d+60 mm. The swirl port 11 is arranged on the upper part of the cylinder body 1a, and the mouth of the swirl port 11 is rectangular, its length b is 0.4d-0.5d mm, and its width a is 0.2d-0.3d mm. The lower end of the conical section cylinder 1b has an underflow opening 12 , the diameter D _d of the underflow opening 12 is 0.3d-0.5d mm, and a valve is provided at the underflow opening 12 .

As shown in Fig. 2, the diameter _Dx of the central exhaust pipe 4 is 0.5d-0.6d mm. (a) of Fig. 6 is a comparison diagram of the influence of the diameter of the central exhaust pipe on the mass transfer effect per unit pressure drop of the hydrojet air cyclone deamination. From this comparison diagram, it can be drawn that the diameter D of the central exhaust pipe 4 When _x is designed to be 0.5d ~ 0.6d mm, the hydrojet air cyclone has the best energy efficiency, that is, the deamination efficiency per unit pressure drop is the highest.

As shown in Figure 2, the insertion depth S of the central exhaust pipe is 0.5H-0.75H mm, and the length h of the nozzle hole area is 0.6S-1S mm. As shown in Figure 6 (b), it is a comparison diagram of the influence of the insertion depth of the central exhaust pipe on the mass transfer effect per unit pressure drop of the hydrojet air cyclone deamination. From this comparison diagram, it can be concluded that the central exhaust pipe When the insertion depth S of the tube 4 is designed to be 0.5H-0.75H mm, the hydrojet air cyclone has the best energy efficiency.

As shown in Figure 2, a plurality of nozzle holes 2 are all arranged on the outer wall of the cylinder section 1a, and their arrangement is designed as a square, and Figure 7 shows that the nozzle holes are arranged in a triangle and a square to deamination the cyclone The comparison chart of mass transfer effect, from the comparison chart, it can be concluded that when the arrangement is designed as a square, the hydrojet air cyclone has better gas-liquid mass transfer efficiency.

As shown in FIG. 2 , the distance between the injection holes 2 and the injection holes 2 is designed such that l _h is 0.15d-0.30d mm. Figure 8 is a comparison diagram of the effect of different nozzle hole spacing on the mass transfer effect of hydrocyclone deamination. From the comparison diagram, it can be concluded that when the nozzle hole spacing l _h is designed to be 0.15d ~ 0.30d mm, the hydrojet air Cyclone has better gas-liquid mass transfer efficiency.

As shown in Fig. 4, the nozzle hole is circular, and its diameter d _h is 0.028d-0.05d mm. The calculation process of the diameter d _h is as follows. The optimal value of the nozzle diameter d _h is 0.14l ₀ ~0.20l ₀ , and l ₀ is the gap between the central exhaust pipe 4 and the cylinder 1a of the cylindrical section (that is, the swirler width of the annular gap), l ₀ =0.5(DD _x )=0.2～0.25d mm, that is to say, d _h is 0.028～0.05d mm. Figure 9 is a comparison diagram of the effect of the diameter of the nozzle hole on the mass transfer effect of the cyclone deamination. From the comparison diagram, it can be concluded that when the diameter d _h of the nozzle hole is designed to be 0.028d ~ 0.05d mm, the hydrojet air cyclone The flow device has better gas-liquid mass transfer efficiency.

The following is an example to illustrate the design and manufacture of a hydrojet air cyclone with an inner diameter D of a cylinder section of 70 mm and its application to the reduction treatment of chromium-containing wastewater.

(1) Production of cyclone:

Select a plexiglass tube with a plate thickness of 5mm and an inner diameter D of 70mm to make the cyclone cylinder of the cyclone. The total length H of the hydrocyclone cylinder should be within 280-350 mm. The value in this embodiment is 300 mm. The separation space is designed as a combination of cone and column. The length H _c of the cone section cylinder is 150 mm. The inner diameter of the cylindrical outer jacket 9 D ₀ is 110-130mm, the diameter D _d of the bottom flow port 12 is 21-35mm, a valve is installed under the bottom flow port 12, the swirl port 11 adopts a conventional cyclone separator spiral rectangular inlet head, and the length b of the swirl port 1 is 28 ~ 35mm, width a is 14 ~ 21mm, the head and the cyclone cylinder are connected by a flange. The diameter D _x of the central exhaust pipe is designed to be 40mm, and the length S inserted into the cyclone cylinder is designed to be 140mm. The nozzle hole spacing l _h should be designed within 10.5 ~ 21mm, the value of this embodiment is 15.7mm, the nozzle holes are arranged in a square, so there are 7 rows of nozzle holes from top to bottom on the cyclone cylinder, and each row has a total of 16 nozzle holes. There are 112 holes in total, and the 16 nozzle holes in each row are evenly distributed on the circumference. The length h of the nozzle hole region should be within 84-140 mm, and the value of this embodiment is 100 mm. The nozzle hole diameter is taken as d _h =0.029d≈2mm. The experimental system consists of a cyclone, a liquid storage tank, a liquid circulation pump, a fan, a sieve plate type gas-liquid separator, and the supporting gas and liquid flowmeters and U-shaped differential pressure gauges for system testing, as shown in Figure 10.

(2) Experimental process:

First use K ₂ Cr ₂ O ₇ to prepare 5L of chromium-containing wastewater with a certain initial concentration, and pour it into the liquid storage tank of the cyclone. Turn on the circulating liquid pump and take the initial sample after 10 minutes of stabilization. Then open the air pump and the SO2 cylinder air valve, adjust the flow rate to the preset value, and start the reduction treatment of chromium _- containing wastewater. Adjust the valve at the bottom flow port of the cyclone, and keep the same liquid level at the bottom of the cyclone in the experiment, so as to realize the liquid seal and ensure that the cyclone gas is discharged through the central exhaust pipe. During the experiment, samples were taken every 0.5 to 2 minutes, and the changes in Cr(Ⅵ) content were analyzed and determined. The concentration of Cr(Ⅵ) in the sample was determined by diphenylcarbazide spectrophotometry at 540nm colorimetrically (GB 7467-87), and the removal rate of Cr(Ⅵ) was defined as:

$\mathrm{<span\; class="notranslate">\; \&eta;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula, c ₀ and c _t refer to the initial and t concentrations of Cr(VI), respectively.

When all the hexavalent chromium is reduced to Cr ³⁺ , the pH of the chromium-containing wastewater is adjusted to 8-9, and Cr ³⁺ will precipitate, which can be recycled after separation and dehydration.

(3) Experimental results:

As shown in Fig. ₁₁ , the efficiency of treating chromium-containing wastewater is very good by using hydrojet air cyclone with SO2 as reducing agent. When the concentration of Cr(Ⅵ) is only 204 mg·L ^-1 , the reduction removal rate of Cr(Ⅵ) can reach over 99.9% after treatment for 2 minutes. This shows that the chromium-containing wastewater with lower Cr(Ⅵ) concentration is more suitable for this treatment process. As the concentration of Cr(Ⅵ) in wastewater increases from 204 mg·L ^-1 to 1982 mg·L ^-1 , the treatment time needs to be extended appropriately, but even if the concentration of Cr(Ⅵ) reaches 1982 mg·L ^-1 , the Cr(Ⅵ) ) reduction removal rate can reach more than 99.9%. The pH of the reduced chromium-containing wastewater is adjusted to 8.5, and the converted Cr ³⁺ can be precipitated and can be recycled after separation.

Embodiment two

As shown in FIG. 12 for the hydrojet air cyclone, the cyclone body 1 can also be a cylindrical body. All the other are the same as the first embodiment.

Claims (7)

1. A hydrojet air cyclone, including an air cyclone and a hydrojet atomization chamber (6), the air cyclone is composed of a central exhaust pipe (4) and a cyclone cylinder (1) set, The upper end of the central exhaust pipe (4) protrudes from the cyclone cylinder (1), and the lower end is lower than the lower end of the hydro-jet atomization chamber (6). The cyclone cylinder (1) is provided with a cyclone Through the swirl port (11), the compressed gas is input into the cyclone cylinder (1), and the compressed gas rotates at a high speed in the cyclone cylinder (1), forming a gas swirl field, and the cyclone There is a cylindrical outer jacket (9) on the periphery of the upper part of the cylinder (1), which is connected with the outer wall of the cyclone cylinder (1) to form a hydrojet atomization chamber (6). The part of the cyclone connected to it A plurality of spray holes (2) are opened on the outer wall of the barrel (1) from top to bottom, and a liquid inlet (10) is arranged on the upper part of the hydraulic spray atomization chamber (6), and the feature is that: the center row The diameter D _x of the trachea (4) is 0.5 d ~ 0.6d mm; the insertion depth S of the central exhaust pipe (4) is 0.5H ~ 0.75 H mm; multiple nozzle holes (2) are arranged in a square array on the cylinder On the outer wall of the section cylinder (1a), and the length h of the nozzle hole area is 0.6S-1S mm. 2. The hydro-jet air cyclone according to claim 1, characterized in that: the nozzle hole (2) is a round hole, its diameter d _h is 0.028 d ~ 0.05 d mm, the nozzle hole (2) and the nozzle The distance l _h between the holes (2) is 0.15d-0.30d mm. 3. The hydrojet air cyclone according to claim 1 or 2, characterized in that: the swirl port (11) is arranged on the upper part of the cylinder (1a), and the swirl port (11) The mouth is rectangular, its length b is 0.4 d ~ 0.5 d mm, and its width a is 0.2 d ~ 0.3 d mm. 4. The hydrojet air cyclone according to claim 1 or 2, characterized in that: the cyclone cylinder (1) is formed by the upper cylindrical section cylinder (1a) and the lower inner diameter gradually decreasing Conical section cylinder (1b); the inner diameter D of the cylindrical section cylinder (1a) is d mm; the total length H of the cyclone cylinder (1) is 4d ~ 5d mm; the conical section cylinder The length H _c of the body (1b) is 2 d to 2.5 d mm. 5. The hydrojet air cyclone according to claim 1 or 2, characterized in that: the lower end of the conical section cylinder (1b) has an underflow opening (12), and the diameter of the underflow opening (12) is D _d It is 0.3d～0.5d mm, and a valve is provided at the underflow port (12). 6. The hydro-jet air cyclone according to claim 1 or 2, characterized in that: the gap _l0 between the central exhaust pipe (4) and the cylinder body (1a) is 0.2d~0.25 d mm. 7. The hydrojet air cyclone according to claim 1 or 2, characterized in that: the inner diameter _D0 of the cylindrical outer jacket (9) is d+40-d+60 mm.