Photocatalytic treatment reactor and photocatalytic method for photosensitive dry film developing waste liquid

Abstract

The invention provides a photo-catalytic treatment reactor and a photo-catalytic method for photosensitive dry film developing waste liquid, the reactor comprises: an outer cylinder, an inner cylinder is arranged in the outer cylinder, the outer cylinder and the inner cylinder form an interlayer for storing waste liquid, the outer cylinder is a closed structure, and a liquid inlet pipeline is arranged on the outer cylinder; the inner cylinder is used for introducing the waste liquid in the interlayer in batches, a photocatalyst is arranged on the inner wall of the inner cylinder, an opening and closing door is mounted on the upper end face of the inner cylinder, and a liquid outlet pipeline is arranged on the lower end face of the inner cylinder, penetrates through the lower end face of the outer cylinder downwards and extends out of the outer cylinder; the opening and closing door is rotationally connected with the inner barrel and connected with a driving part on the inner wall of the outer barrel, and when the opening and closing door is closed, the inner barrel can be closed; a stirring part and a light source are arranged on the rotating shaft, the rotating shaft is connected with the output end of the power part, and the rotating shaft downwards penetrates through the upper end face of the outer cylinder from the outside of the outer cylinder and extends into the inner cylinder. The photocatalytic reaction efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of waste liquid treatment technology generated in the production of photosensitive dry film, and particularly relates to a photocatalytic treatment reactor and photocatalytic method for photosensitive dry film developing waste liquid. Background Technology

[0002] In recent years, with the rapid development of my country's science and technology industry, the demand for photosensitive dry film for printed circuit boards (PCBs) has been increasing. In the production of photosensitive dry film, the developing solution and fixing solution are the main waste liquids generated during the preparation process. Their main components are phenols, ketones such as acetone and butanone, and alkali metal salts such as sodium sulfite and potassium bromide. In the treatment of these waste liquids, chemical oxygen demand (COD) and suspended solids are two important indicators for whether the waste liquid treatment meets the standards.

[0003] Currently, commonly used treatment devices mainly reduce the chemical oxygen demand (COD) of wastewater through oxidation-reduction reactions by adjusting the pH of the wastewater, while simultaneously settling suspended solids, thus ensuring the effluent quality meets the "Integrated Wastewater Discharge Standard" GB8978-1996. This process requires the addition of new chemical substances. Although the COD of the treated wastewater is significantly reduced, the introduction of new chemical components means that true purification is not achieved. Furthermore, power and chemical costs are the two main expenses in the treatment process, amounting to approximately 3.4 yuan / m³. 3 However, the cost is relatively high. Photocatalytic water treatment technology, on the other hand, is highly practical, efficient, and has a low cost of only 2-3 yuan / m³. 3 The advantages of photocatalysis have led to its application from laboratory research. Furthermore, treating wastewater generated during photosensitive dry film preparation using photocatalysis eliminates the need for oxidants, allowing direct oxidation and decomposition of organic and inorganic components in the wastewater by utilizing the oxidizing groups generated by the photocatalyst. Currently, commonly used photocatalysts are titanium dioxide or modified TiO2, with ultraviolet or visible light sources. However, the design of the photocatalytic reactor for treating photosensitive dry film developing wastewater significantly impacts the catalytic reaction's effectiveness. Therefore, designing a highly efficient photocatalytic reactor for treating photosensitive dry film developing wastewater is a major research direction in the current photocatalysis market. Summary of the Invention

[0004] The purpose of this invention is to provide a photocatalytic treatment reactor and photocatalytic method for photosensitive dry film developing wastewater, thereby improving the efficiency of the photocatalytic reaction. The technical solution adopted is as follows:

[0005] A photocatalytic treatment reactor for photosensitive dry film developing waste liquid includes:

[0006] The outer cylinder 1 has an inner cylinder 2 inside it, which together form a jacket for storing waste liquid. It is a closed structure and has an inlet pipe 5 on it.

[0007] The inner cylinder 2 is used to introduce waste liquid into the interlayer in batches. It is equipped with a photocatalyst on its inner wall, an opening and closing door 8 is installed on its upper end face, and a liquid outlet pipe 6 is provided on its lower end face. The liquid outlet pipe 6 passes downward through the lower end face 11 of the outer cylinder and extends to the outside of the outer cylinder 1.

[0008] The opening and closing door 8 is rotatably connected to the inner cylinder 2 and connected to the drive part on the inner wall of the outer cylinder 1. When the opening and closing door 8 is closed, it can seal the inner cylinder 2.

[0009] The rotating shaft 3 is equipped with a stirring part 4 and a light source 7, which is connected to the output end of the power part. It passes through the upper end face of the outer cylinder 1 from the outside of the outer cylinder 1 and extends into the inner cylinder 2.

[0010] Preferably, the inner cylinder 2 includes an arc-shaped cover plate 22; when the opening and closing door 8 is closed, both ends of the cover plate 22 are in contact with the opening and closing door 8.

[0011] Preferably, the driving unit includes:

[0012] Motor 9 and Motor 10 are both located on the inner wall of the outer cylinder 1;

[0013] Conveyor bar 11, one end of which is fixed to the output shaft of motor 9, and the other end of which is fixed to the output shaft of motor 10.

[0014] Several fixed pulleys 12 are located between motor 9 and motor 10; the conveyor bar 11 crosses the fixed pulleys 12;

[0015] And connectors, which connect the opening and closing door 8 and the conveyor bar 11.

[0016] Preferably, both output shafts have arc-shaped grooves, and the conveyor strip fits into the grooves.

[0017] Preferably, the inner cylinder 2 further includes a light source groove 21, a portion of which is formed in the cover plate 22 and the other portion of which is formed in the opening and closing door 8;

[0018] The light source 7 is located within the light source slot 21.

[0019] Preferably, the light source 7 is an LED light strip, which is bonded or embedded in the rotating shaft 3.

[0020] Preferably, the photocatalyst is coated on the inner cylinder 2.

[0021] Preferably, the stirring part 4 is embedded in or fixed to the rotating shaft 3.

[0022] Preferably, the lower end of the rotating shaft 3 is located in the inner cylinder 2 or extends into the interlayer.

[0023] A photocatalytic method, based on a photocatalytic treatment reactor for photosensitive dry film developing waste liquid, includes the following steps:

[0024] The first batch of waste liquid is introduced into the inner cylinder 2 through the opening and closing door 8 for photocatalytic reaction, and then the second to nth batches of waste liquid are introduced sequentially through the opening and closing door 8 for photocatalytic reaction; 2≤n<N;

[0025] Before introducing the next batch of waste liquid, the photocatalytic reaction time is time T; the volume of each batch of waste liquid is v = V / N, where V is the volume of inner cylinder 2 and N is the total number of batches.

[0026] When the photocatalytic reaction time corresponding to the nth batch of waste liquid ends, the treated waste liquid is discharged.

[0027] In the photocatalytic reaction, the rotating shaft 3 is rotatable.

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] By addressing two factors influencing photocatalytic reaction efficiency, the efficiency of photocatalytic reactions was improved. Specifically, these two factors are: the efficiency of reactant flow transfer to the photocatalyst surface and the contact rate between the active species generated by the photocatalyst and the reactants.

[0030] The rotating shaft 3 drives the stirring part 4 to rotate, thereby causing the waste liquid in the inner cylinder 2 to flow, increasing the contact area between the reactants and the active species generated by the photocatalyst, thus increasing the contact rate.

[0031] The waste liquid not introduced into the interlayer serves two purposes: firstly, to reduce the temperature of the waste liquid in the inner cylinder 2, so as to avoid the inner cylinder 2 becoming too hot due to the heat generated by the photocatalytic reaction and the light source 7, which would affect the catalytic activity of the photocatalyst and thus affect the contact rate between the active species generated by the photocatalyst and the reactants.

[0032] Waste liquid is introduced into inner cylinder 2 in batches, so that the reacted waste liquid and unreacted waste liquid in inner cylinder 2 are mixed, thereby forming a concentration gradient, the reactants diffuse quickly, and the transfer efficiency of reactant flow to the surface of photocatalyst is improved. Attached Figure Description

[0033] Figure 1 This is an external view of the photocatalytic treatment reactor for photosensitive dry film developing waste liquid;

[0034] Figure 2 A diagram showing the relative positions of the inner and outer cylinders;

[0035] Figure 3 A diagram showing the relative positions of the outer cylinder, inner cylinder, rotating shaft, and stirring unit;

[0036] Figure 4 for Figure 3 A partial view;

[0037] Figure 5 This is a structural diagram of the drive unit;

[0038] Figure 6 This is a schematic diagram showing the location of the exhaust port.

[0039] Wherein, 1-outer cylinder, 11-lower end face of outer cylinder

[0040] 2-Inner cylinder, 21-Light source slot, 22-Cover plate, 23-Lower end face of inner cylinder

[0041] 3-Shaft, 31-Exhaust port, 32-Exhaust passage

[0042] 4-Stirring section,

[0043] 5-Inlet pipe, 6-Outlet pipe

[0044] 7-Light source,

[0045] 8-Opening and closing doors,

[0046] 9-Motor No. 1, 10-Motor No. 2, 11-Belt, 12-Fixed pulley, 13-Connecting shaft. Detailed Implementation

[0047] The photocatalytic treatment reactor and photocatalytic method for photosensitive dry film developing waste liquid of the present invention will be described in more detail below with reference to schematic diagrams, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being of broad knowledge to those skilled in the art and is not intended to limit the present invention.

[0048] This embodiment designs a device for treating waste liquid during the preparation of photosensitive dry film.

[0049] like Figures 1-6 A photocatalytic reactor for treating waste liquid from photosensitive dry film developing includes: an outer cylinder 1, an inner cylinder 2, a light source 7, a rotating shaft 3, a power unit, an opening and closing door 8, and a drive unit.

[0050] The outer cylinder 1 has an inner cylinder 2 inside it, which together form a jacket for storing waste liquid. It is a closed structure and has an inlet pipe 5 on it.

[0051] Regarding the fixing method of outer cylinder 1:

[0052] The outer cylinder 1 is placed on the support (not shown in the figure).

[0053] The inner cylinder 2 is used to introduce waste liquid into the jacket in batches. It is equipped with a photocatalyst on its inner wall, and an opening and closing door 8 is installed on its upper end face. The liquid outlet pipe 6 is provided on its lower end face. The liquid outlet pipe 6 passes downward through the lower end face 11 of the outer cylinder and extends to the outside of the outer cylinder 1.

[0054] Regarding the fixing method of inner cylinder 2:

[0055] The outer cylinder 1 is equipped with a base.

[0056] The base is fixedly connected to the lower end face 11 of the outer cylinder and the lower end face 23 of the inner cylinder. The base connects the lower end face 11 of the outer cylinder and the lower end face 23 of the inner cylinder.

[0057] The base, in Figures 2-3 None of them are shown in the text.

[0058] The base does not interfere with the liquid outlet pipe 6 or the rotating shaft 3.

[0059] In this embodiment, the photocatalyst is coated on the inner wall of the inner cylinder 2.

[0060] The inner cylinder 2 includes an arc-shaped cover plate 22 and a light source slot 21.

[0061] More specifically, the inner cylinder 2, the cover plate 22, and the lower end face 23 of the inner cylinder are integrally formed.

[0062] The light source groove 21 has a portion formed in the cover plate 22 and another portion formed in the opening and closing door 8, which is open at the top and closed at the bottom.

[0063] like Figure 5 As shown, when the door 8 is closed, both ends of the cover plate 22 are in contact with the door 8. The two parts of the light source slot 21 are joined together to form a complete light source slot 21.

[0064] like Figure 5 As shown, sealing layers are provided on the circumferential surface of the opening and closing door 8 and at both ends of the cover plate 22.

[0065] In this embodiment, both the inner and outer cylinders are made of nylon, aluminum alloy, or stainless steel.

[0066] To isolate the waste liquid and the light source 7, the light source 7 is located inside the light source tank 21, such as... Figure 3 As shown, the introduced waste liquid is located outside the light source tank 21.

[0067] In addition, the inner cylinder 2 is always filled with liquid, and the portion of the light source groove 21 that is not surrounded by liquid and is close to the upper end face of the light source groove 21 has a transition hole (not shown in the figure).

[0068] The gas produced in the photocatalytic reaction overflows upwards from the liquid in the inner cylinder 2, and passes through the transition hole and exhaust hole 31 on the rotating shaft 3 (e.g., Figure 6As shown), exhaust is discharged through exhaust duct 31.

[0069] That is, the exhaust hole 31 is connected to the exhaust channel 31, and the exhaust hole 31 is located inside the light source slot 21.

[0070] The bottom surface of the rotating shaft 3 is closed.

[0071] The light source 7 is an LED light strip, which is attached to the rotating shaft 3 or embedded in the light groove on the surface of the rotating shaft 3.

[0072] Specifically, the light source 7 is formed by several LEDs connected in series, with each LED attached to or embedded in the rotating shaft 3.

[0073] like Figure 3 As shown, the rotating shaft 3 has a stirring part 4 and a light source 7 on it. Figure 3 The image shows only half of the structure of the inner cylinder 2.

[0074] In this embodiment, the stirring part 4 is embedded in or fixed to the rotating shaft 3. The lower end of the rotating shaft 3 is located in the inner cylinder 2 or extends into the interlayer. Figure 3 As shown, the lower end of the rotating shaft 3 extends into the interlayer, and a sealing ring is provided between the rotating shaft 3 and the lower end face 23 of the inner cylinder and the lower end face of the light source groove 21.

[0075] The rotating shaft 3 is connected to the output end of the power unit. It extends downward from the outside of the outer cylinder 1 through the upper end face of the outer cylinder 1 and into the inner cylinder 2. The power unit is a motor, and the motor housing is fixedly installed.

[0076] The functions of the rotating shaft 3 are: 1) to drive the stirring part 4 to rotate, thereby causing the waste liquid in the inner cylinder 2 to flow, increasing the contact area between the reactants and the active species generated by the photocatalyst, thereby increasing the contact rate; 2) the products of photocatalytic reaction decomposition contain solid particles, and by rotating, these solid particles can be prevented from depositing on the inner wall of the inner cylinder 2 and the light source 7 of the rotating shaft 3, thus affecting the photocatalytic effect.

[0077] Furthermore, the rotating shaft 3 rotates intermittently, that is, the motor stops rotating after working for a set time to form a working cycle, and then the motor rotates again to enter the next working cycle.

[0078] The stirring process is carried out intermittently to ensure that the photocatalytic reaction proceeds fully.

[0079] Regarding the installation method of light source 7:

[0080] The rotating shaft 3 is provided with an axially extending exhaust passage 32 (e.g. Figure 6 As shown), the wire of the LED light strip is introduced into the exhaust channel 32 from the exhaust hole 31, and led out of the photosensitive dry film developing waste liquid photocatalytic treatment reactor from the upper end of the exhaust channel 32. One end of the wire leading out of the exhaust channel 32 is connected to the power supply.

[0081] The opening and closing door 8 is rotatably connected to a protrusion (not shown in the figure) on the inner wall of the inner cylinder 2, and is connected to a drive part on the inner wall of the outer cylinder 1. When the opening and closing door 8 is closed, it can seal the inner cylinder 2.

[0082] Regarding the installation method of hinged door 8:

[0083] like Figure 5 As shown, the connecting shaft is embedded in the opening and closing door 8 and extends upward and downward out of the opening and closing door 8. The lower end of the connecting shaft is fitted with the hole on the protrusion with clearance so that the connecting shaft can rotate on the protrusion on the inner cylinder 2.

[0084] Figure 5 The image only shows a section of the connecting shaft extending upwards from the opening and closing door 8. The blue part is the connecting shaft, and the upper part of it is the housing.

[0085] The drive unit includes: motor 9, motor 10, conveyor bar 11, fixed pulley 12, and connecting parts.

[0086] Both motor 9 and motor 10 are embedded in or fixed to the inner wall of the outer cylinder 1 by fasteners;

[0087] The conveyor bar 11 has one end fixed to the output shaft of motor 9 and the other end fixed to the output shaft of motor 10.

[0088] To accommodate the arc-shaped direction of the conveyor bar 11, arc-shaped grooves are provided on both output shafts, and the conveyor bar 11 fits into the grooves.

[0089] To form an arc-shaped path for the conveyor bar 11 and avoid interference between the conveyor bar 11 and the inner cylinder 2, three fixed pulleys 12 are provided, all located between motor 9 and motor 10; the conveyor bar 11 crosses over the fixed pulleys 12.

[0090] "Transmitter bar 11 crosses fixed pulley 12" means that the conveyor bar 11 is attached to the fixed pulley 12 and is located on one side of the central axis of the fixed pulley 12.

[0091] A connector that connects the opening / closing door 8 and the conveyor bar 11.

[0092] In this embodiment, the connector is horizontally arranged, with one end embedded in the opening and closing door 8 and the other end fixed to the conveyor bar 11 by fasteners.

[0093] Working principle of the drive unit:

[0094] Motor 9 rotates to tighten conveyor belt 11, and motor 10 rotates to release conveyor belt 11, thereby opening the opening and closing door 8. Motor 9 and motor 10 rotate in opposite directions.

[0095] Specifically: To open the door 8, motor 9 rotates counterclockwise and motor 10 rotates clockwise.

[0096] Two factors affecting the efficiency of photocatalytic reactions are: the efficiency of reactant flow to the surface of the photocatalyst and the contact rate between the active species generated by the photocatalyst and the reactants.

[0097] A photocatalytic method includes the following steps:

[0098] Step 1: The waste liquid is introduced into the interlayer through the inlet pipe 5, and finally the waste liquid in the interlayer 4.

[0099] Step 2: Introduce the waste liquid into the inner cylinder 2 in batches.

[0100] The first batch of waste liquid is introduced into the inner cylinder 2 through the opening and closing door 8 for photocatalytic reaction, and then the second batch of waste liquid is introduced into the inner cylinder 2 through the opening and closing door 8 for photocatalytic reaction.

[0101] Before introducing the next batch of waste liquid, the photocatalytic reaction time is 3 hours; the volume of each batch of waste liquid is v = V / 3, where V is the volume of the inner cylinder 2;

[0102] After the photocatalytic reaction time corresponding to the second batch of waste liquid is completed, the treated waste liquid is discharged.

[0103] In the photocatalytic reaction, the rotating shaft 3 can rotate, and the waste liquid that has not been introduced into the interlayer surrounds the waste liquid introduced into the inner cylinder 2.

[0104] At this point, the reacted waste liquid and the unreacted waste liquid in the inner cylinder 2 mix, thereby forming a concentration gradient. The reactants (unreacted waste liquid) diffuse quickly, which improves the transfer efficiency of the reactants to the surface of the photocatalyst.

[0105] Photocatalytic reaction: using a photocatalyst (titanium dioxide or modified TiO2) to decompose phenolic and ketone organic compounds in waste liquid.

[0106] "Rotating shaft 3 can rotate" means that rotating shaft 3 rotates intermittently.

[0107] When the rotating shaft 3 rotates, it drives the stirring part 4 to stir the waste liquid. Through convection, the contact rate between the reactants and the active ions (active species) generated by the photocatalyst is increased, so that the reactants and active substances can be fully contacted, so as to avoid the active species (such as electrons and holes) generated by the photocatalyst recombination in a short time, which would affect the catalytic efficiency.

[0108] The waste liquid not introduced into the interlayer serves two purposes: firstly, it lowers the temperature of the waste liquid in the inner cylinder 2 to prevent the temperature of the inner cylinder 2 from becoming too high due to the heat generated by the photocatalytic reaction and the light source 7, which would affect the catalytic activity of the photocatalyst and thus the contact rate between the active species generated by the photocatalyst and the reactants; secondly, the water stored in the interlayer is waste liquid, which is used to prepare for the next batch of reaction.

[0109] Specifically: The catalytic activity of the photocatalyst decreases, the number of active species produced decreases, and ultimately the contact rate between the active species and the reactants decreases.

[0110] Step 3: After the photocatalytic reaction time corresponding to the second batch of waste liquid ends, the treated waste liquid is discharged through the outlet pipe 6.

[0111] According to existing technology: both the inlet pipe 5 and the outlet pipe 6 are equipped with solenoid valves or manual valves.

[0112] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A photocatalytic reactor for treating photosensitive dry film developing waste liquid, characterized in that, include: The outer cylinder (1) has an inner cylinder (2) inside it, which together with the inner cylinder (2) form a jacket for storing waste liquid. It is a closed structure and has an inlet pipe (5) on it. The inner cylinder (2) is used to introduce waste liquid into the interlayer in batches. It is equipped with a photocatalyst on its inner wall, and an opening and closing door (8) is installed on its upper end face. It is equipped with a liquid outlet pipe (6) on its lower end face. The liquid outlet pipe (6) passes through the lower end face (11) of the outer cylinder and extends to the outside of the outer cylinder (1). The opening and closing door (8) is rotatably connected to the inner cylinder (2) and connected to the drive part on the inner wall of the outer cylinder (1). When the opening and closing door (8) is closed, it can close the inner cylinder (2). And a rotating shaft (3), which is provided with a stirring part (4) and a light source (7), which is connected to the output end of the power part, and extends downward from the outer cylinder (1) through the upper end face of the outer cylinder (1) and into the inner cylinder (2).

2. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 1, characterized in that, The inner cylinder (2) includes an arc-shaped cover plate (22); when the opening and closing door (8) is closed, both ends of the cover plate (22) are in contact with the opening and closing door (8).

3. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 2, characterized in that, The drive unit includes: Motor No. 1 (9) and Motor No. 2 (10) are both located on the inner wall of the outer cylinder (1); The conveyor bar (11) has one end fixed to the output shaft of motor 1 (9) and the other end fixed to the output shaft of motor 2 (10). Several fixed pulleys (12) are located between motor 1 (9) and motor 2 (10); the conveyor bar (11) crosses the fixed pulleys (12); and connectors, which connect the opening and closing door (8) and the conveyor bar (11).

4. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 3, characterized in that, Both output shafts have arc-shaped grooves, and the conveyor strip fits into the grooves.

5. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 2, characterized in that, The inner cylinder (2) also includes a light source groove (21), part of which is formed in the cover plate (22) and the other part of which is formed in the opening and closing door (8); The light source (7) is located inside the light source slot (21).

6. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 1, characterized in that, The light source (7) is an LED light strip, which is bonded or embedded in the rotating shaft (3).

7. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 1, characterized in that, The photocatalyst is coated on the inner cylinder (2).

8. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 1, characterized in that, The stirring part (4) is embedded in or fixed to the rotating shaft (3).

9. The photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to claim 1, characterized in that, The lower end of the rotating shaft (3) is located in the inner cylinder (2) or extends into the interlayer.

10. A photocatalytic method, based on the photocatalytic treatment reactor for photosensitive dry film developing waste liquid according to any one of claims 1 to 9, characterized in that, Includes the following steps: The first batch of waste liquid is introduced into the inner cylinder (2) through the opening and closing door (8) for photocatalytic reaction, and then the second to nth batches of waste liquid are introduced in sequence through the opening and closing door (8) for photocatalytic reaction; 2≤n<N; Before introducing the next batch of waste liquid, the photocatalytic reaction time is time T; the volume of each batch of waste liquid is v = V / N, where V is the volume of the inner cylinder (2) and N is the total number of batches. When the photocatalytic reaction time corresponding to the nth batch of waste liquid ends, the treated waste liquid is discharged. In the photocatalytic reaction, the rotating shaft (3) is rotatable.

Images