Bench-scale device for ozone catalytic system

Abstract

Disclosed in the present invention is a bench-scale device for an ozone catalytic system, the bench-scale device comprising: a catalysis unit, a liquid transfer unit, and a gas treatment unit, wherein a catalytic reaction can occur inside the catalysis unit, the liquid transfer unit is communicated with two sides of the catalysis unit, and the gas treatment unit is communicated with a top end and a bottom end of the catalysis unit. The catalysis unit comprises: a housing, wherein the interior of the housing is provided with a cavity for the catalytic reaction, and a top end of the housing is provided with an opening for the cleaning and maintenance of the catalysis unit; a cover plate placed at the top end of the housing for sealing the opening; and a supporting tray used for supporting a catalysis layer. The supporting tray comprises a first support plate and a mesh screen, wherein the first support plate is fixed at one third to one half of the height of the housing, is fixed on the inner wall of the housing in parallel to the bottom surface of the housing, and has the same size as the bottom surface of the housing; the surface of the first support plate is provided with a plurality of first flow-through holes; and the mesh screen is arranged on the upper surface of the first support plate.

Description

Ozone catalytic system small test device TECHNICAL FIELD

[0001] The present application relates to the field of sewage treatment, in particular to a kind of ozone catalytic system small test device. BACKGROUND

[0002] Chemical oxygen demand (COD, Chemical Oxygen Demand) indicates the oxygen required for oxidation of organic matter in one liter of sewage under strong acidic conditions Potassium dichromate or potassium permanganate and other oxidants, can generally indicate the amount of organic matter in sewage.COD is an important indicator of water pollution, which can reflect the degree of water pollution.

[0003] At present, the COD treatment technology in the field of sewage treatment mainly includes biology, physics (activated carbon adsorption technology), chemistry (chemical oxidation technology, ozone oxidation technology, etc.), among which, ozone oxidation technology has the advantages of simple process, convenient ozone preparation, flexible operation and no secondary pollution, etc., and its principle is mainly the process of producing hydroxyl radical (·OH) by ozone under the action of catalyst to oxidize organic matter, ·OH produced by O3 decomposition as a strong oxidant, almost no selectivity and all pollutants in sewage, the macromolecular organic matter in pollutants is broken into small molecular organic matter, and finally converted into carbon dioxide and water. Therefore, ozone catalytic oxidation technology is highly valued in the field of sewage treatment, especially in the field of sewage advanced treatment, and plays an important role in the removal of refractory organic matter and the removal of color.

[0004] The existing invention technology about ozone catalytic system is mainly engineering application, and for engineering design, catalyst selection verification and ozone catalytic degradation COD capacity verification are a key step, therefore, a simple structure, low cost and adjustable device needs to be designed to meet the engineering design requirements of catalyst selection and sewage degradation capacity verification. SUMMARY

[0005] The purpose of the present application is to provide an ozone catalytic system small test device, which has the advantages of simple structure, easy to build and low cost, and is used for catalyst selection verification in the early stage of sewage treatment system design, verification of sewage treatment effect, and rapid support data for engineering design and application.

[0006] In order to achieve the above purpose, the present application provides an ozone catalytic system small test device, which comprises: a catalytic unit, a liquid transmission unit and a gas treatment unit, the catalytic unit can occur catalytic reaction inside, the liquid transmission unit is communicated and arranged on both sides of the catalytic unit, and the gas treatment unit is communicated and arranged at the top and bottom of the catalytic unit.

[0007] The catalytic unit comprises:

[0008] a shell, which is internally provided with a cavity for catalytic reaction, and which is provided with an opening at the top end for cleaning and maintenance of the catalytic unit;

[0009] a cover plate, which is placed at the top end of the shell to seal the opening;

[0010] a supporting tray for supporting the catalytic layer, which comprises a first supporting plate and a gauze, the first supporting plate is fixed to the shell at a height of one third to one half of the shell, is fixed to the inner wall of the shell in parallel to the bottom surface of the shell, and has a size consistent with the bottom surface of the shell; the surface of the first supporting plate is provided with a plurality of first flow-through holes; and the gauze is arranged on the upper surface of the first supporting plate.

[0011] Optionally, a second supporting plate is further arranged on the upper surface of the catalytic layer; the size of the second supporting plate is consistent with the size of the first supporting plate, and the surface of the second supporting plate is provided with a plurality of second flow-through holes.

[0012] Optionally, the bottom of the side wall of the shell is provided with a first through hole and a second through hole as an inlet of the catalytic unit; the top of the side wall of the shell is provided with a third through hole as an outlet of the catalytic unit, and the height difference between the inlet and the outlet is proportional to the residence time of the sewage in the catalytic unit.

[0013] Optionally, the third through hole of the shell is arranged on the opposite side wall of the first through hole and the second through hole, and the distance between the third through hole and the top end of the shell is greater than 5 cm.

[0014] Optionally, the cover plate is detachable, and the surface of the cover plate is provided with a fourth through hole to discharge the gas in the catalytic unit.

[0015] Optionally, the liquid transmission unit comprises:

[0016] a water inlet pipe, which is communicatively arranged on the first through hole of the shell to transmit the sewage to be treated into the catalytic unit;

[0017] a first flow meter, which is arranged on the water inlet pipe to control the flow rate of the sewage to be treated into the catalytic unit;

[0018] a water outlet pipe, which is communicatively arranged on the third through hole of the shell to discharge the treated sewage.

[0019] Optionally, the gas treatment unit comprises:

[0020] an air inlet pipe, which is communicatively arranged on the second through hole of the shell to transmit the ozone gas into the catalytic unit;

[0021] a second flow meter, which is arranged on the air inlet pipe to control the flow rate of the ozone gas into the catalytic unit;

[0022] The air distribution pipe is arranged at the bottom end of the shell and comprises a main pipe and a plurality of branch pipes; one end of the main pipe is connected with the air inlet pipe, and the other end is sealed; the surface of the main pipe is provided with two rows of mounting holes arranged symmetrically, and the spacing between each mounting hole in each row is the same; one end of each of the plurality of branch pipes is connected with the main pipe through a joint, so that the port of the branch pipe corresponds to the mounting hole on the main pipe, and the other end of the branch pipe is sealed.

[0023] The air outlet pipe is arranged in communication with the fourth through hole of the cover plate and is used for discharging the ozone gas not involved in the reaction in the catalytic unit and the gas generated after the reaction.

[0024] Optionally, a plurality of air outlet holes are uniformly distributed on the surface of the branch pipe, so that the ozone gas is uniformly discharged from the air distribution pipe in the form of bubbles; the diameter of the air outlet hole ranges from 0.2 mm to 2 mm.

[0025] Optionally, a rubber film is sleeved on the surface of the branch pipe, and a plurality of micro air outlet holes are arranged on the surface of the rubber film, and the diameter of the micro air outlet hole is less than 0.5 microns.

[0026] Optionally, the gas treatment unit further comprises a tail gas processor, the tail gas processor is arranged on the cover plate and is connected with the air outlet pipe; the tail gas processor is internally provided with a temperature-rising resistance wire, which converts the unreacted ozone in the air outlet pipe into oxygen and discharges it into the atmosphere.

[0027] Compared with the prior art, the technical scheme of the present application has at least the following beneficial effects:

[0028] The device of the present application has simple structure and is easy to build. The device can be built by using acrylic plates with low cost, and the internal structure can be adjusted according to experimental requirements, which facilitates the selection and verification of catalysts in the early engineering design, the verification of sewage treatment effect, and the rapid provision of supporting data for engineering design and application. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 is a structural schematic view of the ozone catalytic system small-scale device of the present application.

[0030] Fig. 2 is a structural schematic view of the air distribution pipe in the ozone catalytic system small-scale device of the present application.

[0031] In the figure, 1 is a shell, 2 is a cover plate, 3 is a supporting tray, 31 is a catalytic layer, 41 is a water inlet pipe, 42 is a water outlet pipe, 43 is a first flow meter, 51 is an air inlet pipe, 52 is an air outlet pipe, 53 is a second flow meter, 54 is an air distribution pipe, 541 is a main pipe, 542 is a branch pipe, and 6 is a tail gas processor. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0033] In the description of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] As shown in Figure 1, the ozone catalytic system small test device of the present application comprises a catalytic unit, a liquid transmission unit and a gas treatment unit. The catalytic unit can have a catalytic reaction inside, the liquid transmission unit is communicatively arranged on both sides of the catalytic unit, and the gas treatment unit is communicatively arranged at the top and bottom of the catalytic unit.

[0036] The catalytic unit comprises a cover plate 2, a shell 1 and a supporting tray 3. The shell 1 is a rectangular parallelepiped structure with an open top, and has a cavity inside for catalytic reaction. The open top is used for cleaning and maintenance of the device. A first through hole and a second through hole are arranged in the vertical direction from top to bottom at the bottom of the side wall of the shell 1, which are the feeding ports of the catalytic unit. A third through hole is arranged at the top of the side wall of the shell 1, which is the discharging port of the catalytic unit. The height difference between the feeding port and the discharging port of the catalytic unit is proportional to the residence time of sewage in the catalytic unit. The cover plate 2 is detachably arranged at the top of the shell 1, and the top opening of the shell 1 is sealed by sealing glue during use. The surface of the cover plate 2 is provided with a fourth through hole, which can discharge the reacted gas in the catalytic unit.

[0037] In the preferred embodiment, the third through-hole of the shell 1 is arranged on the opposite side wall of the first and second through-holes, and the distance between the third through-hole and the top end of the shell 1 is greater than 5 cm, which provides space for the escape of the gas in the catalytic unit and prevents sewage from entering the fourth through-hole on the cover plate 2.

[0038] The supporting tray 3 is used to support the catalytic layer 31, which is usually filled with spherical catalyst particles with a diameter of 2-4 mm made of silicon, carbon or aluminum. The catalytic layer 31 can stabilize the flow of fluid flowing through the inside of the catalytic layer 31 and increase the residence time of sewage in the catalytic unit.

[0039] The supporting tray 3 includes a first support plate and a gauze. The first support plate is fixed to one-third to one-half of the height of the shell 1, is fixed to the inner wall of the shell 1 parallel to the bottom surface of the shell 1, and has the same size as the bottom surface of the shell 1, thereby dividing the internal cavity of the shell 1 into a first inner cavity below and a second inner cavity above. The surface of the first support plate is provided with a plurality of first flow-through holes for communicating the first inner cavity with the second inner cavity. The gauze is arranged on the upper surface of the first support plate, and the pore diameter thereof is between 1-2 mm, thereby preventing the catalyst particles in the catalytic layer 31 from blocking the first flow-through holes on the first support plate.

[0040] Further, when the density of the catalytic layer 31 is less than or equal to the density of the sewage, a second support plate can be placed on the upper surface of the catalytic layer 31 to prevent the catalyst particles therein from floating up. Specifically, the second support plate has the same size as the first support plate, is fixed to the inner wall of the shell 1, further divides the second inner cavity into a third inner cavity and a fourth inner cavity, and is provided with a plurality of second flow-through holes on the surface thereof for communicating the third inner cavity with the fourth inner cavity. It can be understood that, at this time, the internal cavity of the entire shell 1 is sequentially divided into the first inner cavity, the third inner cavity and the fourth inner cavity from bottom to top by the first support plate and the second support plate, and the catalytic layer 31 is arranged in the third inner cavity.

[0041] In the preferred embodiment, the thickness of the supporting tray 3 is greater than 3 mm, and the surfaces of the first support plate and the second support plate are uniformly distributed with a plurality of flow-through holes, each flow-through hole has a diameter smaller than the diameter of the catalyst particles, and the spacing between adjacent flow-through holes is greater than or equal to twice the diameter of the catalyst particles.

[0042] The liquid transmission unit includes a water inlet pipe 41, a water outlet pipe 42 and a first flow meter 43. The water inlet pipe 41 is communicatively arranged on the first through-hole of the shell 1 to transmit the sewage to be treated into the first inner cavity of the shell 1 of the catalytic unit. The first flow meter 43 is arranged on the water inlet pipe 41 to control the flow of the sewage to be treated into the catalytic unit. The water outlet pipe 42 is communicatively arranged on the third through-hole of the shell 1 to discharge the treated sewage.

[0043] The gas treatment unit comprises an inlet pipe 51, a gas distribution pipe 54, an outlet pipe 52, a second flow meter 53, and a tail gas processor 6. The inlet pipe 51 is arranged in communication with the second through hole of the shell 1, and is used to transmit ozone gas into the first inner cavity of the shell 1 of the catalytic unit. The second flow meter 53 is arranged on the inlet pipe 51, and is used to control the flow rate of the gas entering the catalytic unit. The outlet pipe 52 is arranged in communication with the fourth through hole of the cover plate 2, and is used to discharge ozone gas that does not participate in the reaction in the catalytic unit and carbon dioxide gas generated after the reaction. The tail gas processor 6 is arranged on the cover plate 2, and is connected with the outlet pipe 52. The tail gas processor 6 is internally provided with electrically heated wires, and can be heated to 400℃. The tail gas processor 6 is used to convert the unreacted ozone in the outlet pipe 52 into oxygen, and discharge the oxygen into the atmosphere.

[0044] As shown in FIG. 2, the gas distribution pipe 54 is arranged at the bottom end of the first inner cavity of the shell 1, and comprises a main pipe 541 and a plurality of branch pipes 542. One end of the main pipe 541 is connected with the inlet pipe 51, and the other end is sealed. The surface of the main pipe 541 is provided with two rows of mounting holes arranged symmetrically. The spacing between each mounting hole in each row is the same. One end of each of the branch pipes 542 is connected with the main pipe 541 through a joint, so that the port of the branch pipe 542 corresponds to the mounting hole on the main pipe 541. The other end of the branch pipe 542 is sealed. The surface of each of the branch pipes 542 is uniformly provided with a plurality of outlet holes, so that the ozone gas can be uniformly discharged from the gas distribution pipe 54 in the form of bubbles. The diameter of the outlet holes ranges from 0.2mm to 2mm.

[0045] In the preferred embodiment, a rubber film containing a large number of micro outlet holes can be further sleeved on the surface of the branch pipe 542. The diameter of the micro outlet holes on the rubber film is less than 0.5 microns. The diameter of the bubbles diffused from the gas distribution pipe 54 is smaller, the area of the gas-liquid interface is increased, and the mass transfer efficiency is improved.

[0046] When the device is used for sewage treatment, the sewage to be treated enters the first inner cavity of the catalytic unit through the water inlet pipe 41, and the flow of the sewage to be treated can be adjusted by the first flow meter 43, thereby controlling the residence time of the sewage to be treated in the catalytic unit. At the same time, the ozone gas enters the gas distribution pipe 54 through the gas inlet pipe 51 and is discharged from the gas distribution pipe 54 to the first inner cavity of the catalytic unit in the form of bubbles, and the flow of the ozone gas can be adjusted by the second flow meter 53 to control the density of the ozone bubbles in the sewage. At this time, the sewage and ozone bubbles in the first inner cavity move upward under the action of water pressure, and when passing through the supporting tray 3 and the catalytic layer 31 in the third inner cavity, the residence time of the sewage and ozone bubbles in the catalytic unit is further increased, so that the sewage and ozone are fully contacted; at the same time, under the action of the catalyst, the ozone will quickly decompose the pollutants in the sewage, and the pollutants will be converted from large molecular organic matter to small molecular organic matter, and finally converted into carbon dioxide and water. The treated sewage is discharged from the water outlet pipe 42 communicating with the fourth inner cavity, and the ozone gas that does not participate in the reaction in the catalytic unit and the carbon dioxide gas generated after the reaction are discharged through the gas outlet pipe 52 at the top and enter the tail gas treater 6 to remove the ozone and then discharged into the atmosphere. The residence time of the sewage in the entire catalytic unit is controlled between 0.5-2h.

[0047] Example one

[0048] In this embodiment, the shell 1, the cover plate 2 and the first support plate of the device are all made of transparent acrylic material, which facilitates observation of the gas-liquid mixing condition in the device; the length, width and height of the shell 1 are in the ratio of 1:1:1.5, and the specific size can be determined according to the actual sewage treatment capacity. The cover plate 2 is fixed on the top end of the shell 1 by using sealing glue, so as to ensure that the cover plate 2 can seal the top opening of the shell 1 during use of the device. The first support plate is fixed on the inner wall of the shell 1 by hot melting, and is used for placing the catalytic layer 31.

[0049] The catalytic layer 31 selects aluminum-based spherical catalyst particles with a diameter of 2-4mm, and covers the supporting tray 3; the thickness of the catalytic layer 31 can be one-twelfth of the effective water depth to one-fourth of the effective water depth, and the specific thickness can be determined according to the fixed position of the supporting tray 3. The higher the fixed position of the supporting tray 3, the smaller the thickness of the catalytic layer 31.

[0050] The gas distribution pipe 54 is made of ABS engineering plastic, and the length of the main pipe 541 and the branch pipe 542 is determined according to the size of the bottom surface of the shell 1, so that the main pipe 541 and the branch pipe 542 cover the bottom surface of the shell 1; the diameter of the main pipe 541 and the branch pipe 542 is between 20-50mm, and the diameter of the main pipe 541 is greater than or equal to the diameter of the branch pipe 542.

[0051] In the embodiment, the residence time of the sewage in the device is controlled to be 1h by adjusting the first flow meter 43, and the ozone adding concentration is 100mg / L by adjusting the second flow meter 53. As shown in Table 1, the sewage in the effluent pipe 42 of the device is sampled every 4h, and the sewage before and after treatment is analyzed by potassium dichromate oxidation method to measure the change of the chemical oxygen demand in the sewage, thereby verifying that the device can continuously treat the sewage, and the catalytic oxidation effect can be sustained.

[0052] Table 1 Sewage treatment results

[0053] Water sample Influent COD Cr (mg / L) Effluent COD Cr (mg / L) Removal rate (%) The first time 813 161.7 The second time 852 768.2 The third time 793 062.0 The fourth time 753 546.7 The fifth time 803 358.7 The sixth time 763 850.0

[0054] In summary, the device has simple structure, is easy to build, has low building cost, and the internal structure can be adjusted according to experimental requirements, so that the selection and verification of the catalyst in the early engineering design, the verification of the sewage treatment effect, and the rapid provision of support data for engineering design and application are facilitated.

[0055] Although the content of the present application has been described in detail by the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After reading the above content, various modifications and alternatives of the present application will be apparent to those skilled in the art. Therefore, the protection scope of the present application should be defined by the appended claims.

Claims

1. A small scale device for an ozone catalytic system, characterized in that, The application relates to a sewage treatment device. The device comprises a catalytic unit, a liquid transmission unit and a gas treatment unit. The catalytic unit is internally provided with a cavity for catalytic reaction. The top of the catalytic unit is provided with an opening for cleaning and maintenance. A cover plate is arranged on the top of the catalytic unit to seal the opening. A supporting plate is arranged on the top of the catalytic unit.

2. The small scale ozone catalytic system test unit according to claim 1, wherein, The supporting plate is fixed to the inner wall of the catalytic unit.

3. The small scale ozone catalytic system test unit of claim 1, wherein, The top of the catalytic unit is provided with a second supporting plate.

4. The small scale ozone catalytic system test unit of claim 3, wherein, The second supporting plate is fixed to the inner wall of the catalytic unit.

5. The small scale ozone catalytic system test unit of claim 3, wherein, The bottom of the catalytic unit is provided with a first through hole and a second through hole.

6. The small scale ozone catalytic system test unit of claim 3, wherein, The top of the catalytic unit is provided with a third through hole. The liquid transmission unit comprises a water inlet pipe, a first flow meter and a water outlet pipe.

7. The small scale ozone catalytic system test unit of claim 5, wherein, The gas treatment unit comprises an air inlet pipe, a second flow meter, a gas distribution pipe and an air outlet pipe. The air inlet pipe is connected to the second through hole of the catalytic unit. The second flow meter is arranged on the air inlet pipe. The gas distribution pipe is arranged on the bottom of the catalytic unit. The air outlet pipe is connected to the fourth through hole of the cover plate.

8. The small scale ozone catalytic system test unit of claim 7, wherein, The surface of the gas distribution pipe is provided with a plurality of gas outlet holes.

9. The small scale ozone catalytic system test unit of claim 8, wherein, The surface of the gas distribution pipe is provided with a rubber film. The rubber film is provided with a plurality of micro gas outlet holes.

10. The small scale ozone catalytic system test unit of claim 7, wherein, The gas treatment unit further comprises a tail gas processor arranged on the cover plate and connected with the gas outlet pipe; the tail gas processor is internally provided with temperature-rising resistance wires to convert the unreacted ozone in the gas outlet pipe into oxygen and discharge into the atmosphere.

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