Oil-water separation equipment

Abstract

The invention discloses oil-water separation equipment, which comprises a first filtering unit, a second filtering unit, a third filtering unit and a fourth filtering unit, the second filtering unit is positioned at the downstream of the first filtering unit and comprises a solid-liquid separation assembly; the third filtering unit is positioned at the downstream of the second filtering unit and comprises a membrane filtering device; the clear water pool and the sewage pool are located at the downstream of the third filtering unit, fluid filtered by the third filtering unit is discharged through the flow dividing unit by selecting one of the clear water pool and the sewage pool, and the flow dividing unit comprises a main pipeline connected with the membrane filtering device, a first branch pipe connected with the clear water pool, a second branch pipe connected with the sewage pool and a control valve. The main pipeline is provided with a first oil quantity detector, and the control valve controls connection and disconnection of the first branch pipe and the second branch pipe. The device is mainly used for achieving the effect of optimizing rainwater and oil stain separation.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to an oil-water separation device. Background Art

[0002] Traditional oil-water separation devices have many defects. Their control logic is single, relying on a single sensor and unable to dynamically adapt to complex working conditions, resulting in unstable separation efficiency (the measured fluctuation reaches ±15%); the energy consumption and maintenance costs are high. The annual average cost of manual slag cleaning and oil drainage exceeds 500,000 yuan, and the shutdown for maintenance reduces the treatment efficiency by 30%; the device has a large volume and is difficult to adapt to frequently moving working conditions. The root cause is that the structure simply adopts sedimentation, hydrocyclone or centrifugal separator 12, resulting in low separation efficiency and poor working condition adaptability. Particularly importantly, the separation of rainwater and oil is not thorough, still causing pollution. Summary of the Invention

[0003] The purpose to be achieved by the present invention is to provide an oil-water separation device, which solves any of the above problems and achieves the effect of optimizing the separation of rainwater and oil.

[0004] To achieve the above purpose, the present invention adopts the following technical scheme: An oil-water separation device, characterized in that it includes a first filtration unit, which includes a filter screen for filtering coarse particles; a second filtration unit downstream of the first filtration unit, which includes a solid-liquid separation component; a third filtration unit downstream of the second filtration unit, which includes a membrane filtration device; a clean water tank and a sewage tank downstream of the third filtration unit. The fluid filtered by the third filtration unit is discharged to either the clean water tank or the sewage tank through a diversion unit. The diversion unit includes a main pipeline connected to the membrane filtration device, a first branch pipe connected to the clean water tank, a second branch pipe connected to the sewage tank, and a control valve. A first oil quantity detector is provided on the main pipeline, and the control valve controls the on-off of the first branch pipe and the second branch pipe.

[0005] After adopting the above technical solution, the present invention has the following advantages: By adopting a filtering method combining the first filtering unit, the second filtering unit and the third filtering unit, the first filtering unit and the second filtering unit can remove larger particulate impurities, suspended solids and part of the floating oil in the mixed liquid, effectively reducing the burden on the subsequent third filtering unit and extending the service life of the equipment. The third filtering unit then deeply processes the mixed liquid after coarse filtration to separate tiny oil droplets in the water or oil droplets emulsified and dissolved in the water, greatly reducing the oil content in the water. The first oil quantity detector can accurately detect the oil content of the discharged liquid in real time. By judging the oil content, the control valve controls the opening and closing states of the first branch pipe and the second branch pipe according to the detection result of the first oil quantity detector. When it is detected that the discharged liquid meets the discharge standard, the control valve controls the first branch pipe to open and the liquid flows into the clean water tank; if the detection result does not meet the standard, the control valve controls the second branch pipe to open and the liquid flows into the sewage tank for re-treatment. This method realizes the automatic operation of the equipment without frequent manual intervention, not only greatly improving the operation efficiency and stability of the equipment. At the same time, it ensures the continuity and reliability of the entire separation process, ensuring that only the liquid meeting the discharge standard is allowed to flow into the clean water tank, effectively avoiding environmental pollution problems caused by excessive emissions.

[0006] Further, the sewage tank is connected to the upstream of the membrane filtration device through a reflux pipeline.

[0007] Adopting the foregoing technical solution, if the detection result does not meet the standard, the mixed liquid is re-circulated to the upstream of the membrane filtration device through the reflux pipeline for re-filtration to ensure that the final liquid meets the standard and guarantee the quality of the treated liquid.

[0008] Further, it includes an oil collection container, and the oil droplets separated by the second filtering unit and the third filtering unit are collected into the oil collection container.

[0009] Further, a first sensor for detecting the pressure difference of the membrane filtration device is provided on the main pipeline.

[0010] Adopting the foregoing technical solution, the first pressure sensor 23 is arranged on the main pipeline and can monitor the pressure difference data of the filter membrane in real time. During the filtration process, when the filtration resistance changes due to reasons such as impurity accumulation, blockage or aging of the filter membrane, the pressure difference will change accordingly. Enabling the operator to understand the working state of the filter membrane according to the data of the first sensor and intervene in possible abnormal situations in advance.

[0011] Further, it also includes a sand collection container, and the sediment separated by the second filtering unit is collected into the sand collection container.

[0012] Further, the sand collection container is provided with a liquid level gauge.

[0013] With the foregoing technical solution, the liquid level gauge is installed on the sand collecting container, which can monitor the liquid level height of the sediment in the sand collecting container in real time and reflect the accumulation degree of the sediment. The operator can understand the real-time state of the sediment in the sand collecting container at any time through the data of the liquid level gauge, avoiding the overflow of the sediment from the container.

[0014] Further, the solid-liquid separation assembly includes a hydrocyclone solid-liquid separator 11 and a centrifugal separator 12. The upstream side of the hydrocyclone solid-liquid separator 11 is connected to the first filtering unit, and the downstream side of the hydrocyclone solid-liquid separator 11 is connected to the centrifugal separator 12.

[0015] Further, a second pressure sensor for detecting whether the upstream of the hydrocyclone solid-liquid separator 11 is blocked by sediment is provided on the pipeline connecting the hydrocyclone solid-liquid separator 11 and the first filtering unit.

[0016] With the foregoing technical solution, the second pressure sensor is arranged upstream of the first filtering unit and can monitor the pressure value at this position in real time. When the sediment accumulates gradually upstream, the resistance of the mixed liquid flow will increase significantly, leading to an increase in the upstream pressure. The second pressure sensor will capture this pressure change, enabling the operator to detect the possible blockage of the first filtering element in the first time according to the data of the second pressure sensor, so that the operator can intervene at the initial stage of the blockage to ensure the stable operation of the equipment.

[0017] Further, a third pressure sensor 18 for detecting whether the pipeline connecting the hydrocyclone solid-liquid separator 11 and the centrifugal separator 12 is blocked by oil droplets is provided on the pipeline.

[0018] With the foregoing technical solution, the third pressure sensor 18 is installed on the pipeline connecting the hydrocyclone solid-liquid separator 11 and the centrifugal separator 12, and can monitor the pressure condition in the pipeline in real time. When the inner wall of the pipeline becomes thicker due to the adhesion of oil stains, resulting in a reduction in the flow space and an increase in the water flow resistance, the pressure in the pipeline will change accordingly. The operator can intervene at the initial stage when the blockage problem appears according to the data of the third pressure sensor 18, avoiding the shutdown of the system caused by the complete blockage of the pipeline.

[0019] Further, the control valve includes a first valve body 212a and a second valve body 212b; alternatively, the control valve is configured as a two-way fluid switching valve and is arranged at the intersection of the main pipeline and the first branch and the second branch. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings:

[0021] Figure 1 It is a schematic structural diagram of an oil-water separation device of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention.

[0023] The terms "first", "second", etc. (if any) in the specification and claims of the present invention are used to distinguish similar objects rather than to describe a specific order or sequence. Even if "second" is used to distinguish a certain technical feature, it does not necessarily imply the existence of "first". It should be understood that in the present invention, "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. It should be understood that in the present invention, "a plurality of" means two or more. "And / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, X and / or Y may represent: X exists alone, X and Y exist simultaneously, and Y exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "Including X, Y, and Z" and "including X, Y, Z" mean that X, Y, and Z are all included. "Including X, Y, or Z" means including any one of X, Y, and Z. "Including X, Y, and / or Z" means including any one, any two, or all three of X, Y, and Z.

[0024] The technical solutions of the present invention will be described in detail below with specific embodiments. These specific embodiments can be combined or replaced according to the actual situation. For the same or similar concepts or processes, they may not be repeated in some embodiments.

[0025] As Figure 1 shown, the present invention provides an oil-water separation device, which is characterized in that it includes a first filtration unit, which includes a filter screen 500 for filtering coarse particles; a second filtration unit located downstream of the first filtration unit, which includes a solid-liquid separation component; a third filtration unit located downstream of the second filtration unit, which includes a membrane filtration device 25; a clean water tank 100 and a sewage tank 200 located downstream of the third filtration unit. The fluid filtered by the third filtration unit is discharged to either the clean water tank 100 or the sewage tank 200 through a diversion unit. The diversion unit includes a main pipeline 251 connected to the membrane filtration device 25, a first branch pipe 110 connected to the clean water tank 100, a second branch pipe 210 connected to the sewage tank 200, and a control valve. A first oil quantity detector 211 is provided on the main pipeline 251, and the control valve controls the on-off of the first branch pipe 110 and the second branch pipe 210.

[0026] It can be understood that by adopting a filtering method combining the first filtering unit, the second filtering unit and the third filtering unit, the first filtering unit and the second filtering unit can remove larger particle impurities, suspended solids and part of the floating oil in the mixed liquid, effectively reducing the burden on the subsequent third filtering unit and prolonging the service life of the equipment. The third filtering unit then deeply processes the mixed liquid that has been roughly filtered to separate tiny oil droplets or emulsified oil droplets dissolved in water, greatly reducing the oil content in the water. The first oil content detector 211 can accurately detect the oil content of the discharged liquid in real time. By judging the oil content, the control valve controls the opening and closing states of the first branch pipe 110 and the second branch pipe 210 according to the detection result of the first oil content detector 211. When it is detected that the discharged liquid meets the discharge standard, the control valve controls the first branch pipe 110 to open, and the liquid flows into the clean water tank 100; if the detection result does not meet the standard, the control valve controls the second branch pipe 210 to open, and the liquid flows into the sewage tank 200 for re-treatment. This method realizes the automatic operation of the equipment without frequent manual intervention, not only greatly improves the operation efficiency and stability of the equipment. At the same time, it ensures the continuity and reliability of the entire separation process, ensuring that only the liquid that meets the discharge standard is allowed to flow into the clean water tank 100, effectively avoiding environmental pollution problems caused by excessive emissions.

[0027] The control valve includes a first valve body 212a and a second valve body 212b, and both the first valve body 212a and the second valve body 212b adopt globe valves that can control the flow rate of the mixed liquid.

[0028] The control valve is configured as a two-way fluid switching valve and is arranged at the intersection of the main pipeline and the first branch 110 and the second branch 210. This valve body can switch the flow direction of the mixed liquid through a mechanical structure, controlling the selective flow of the mixed liquid between the sewage tank 200 and the clean water tank 100.

[0029] The above-mentioned membrane filtration device includes multiple groups of filter membranes. Specifically, 6 groups of filter membranes are preferably arranged in this embodiment, and the filter membranes adopt a new type of reverse osmosis material, which has super hydrophilicity and underwater super oleophobicity, and can significantly improve the separation efficiency and oil interception rate.

[0030] The sewage tank 200 is connected to the upstream of the membrane filtration device 25 through a reflux pipeline 220. If the detection result does not meet the standard, the mixed liquid can be re-circulated to the upstream of the membrane filtration device 25 through the reflux pipeline 220 for re-filtration to ensure that the final liquid meets the standard and guarantee the quality of the treated liquid.

[0031] It should be noted that for the re - treatment of the mixed liquid, if the final discharge standard is still not met after re - filtering upstream of the membrane filtration device 25, then manual intervention is adopted to increase the number of filter membranes 25 to re - filter the non - compliant mixed liquid until the mixed liquid meets the discharge standard.

[0032] Upstream of the first oil quantity detector 211, there is a vacuum pump 22, which is used to introduce the mixed liquid to be treated upstream into the membrane filtration device 25 to provide power.

[0033] And on the main pipeline 251, there is a first pressure sensor 23 for detecting the pressure difference of the membrane filtration device 25. The first pressure sensor 23 is arranged on the main pipeline 251 and can monitor the pressure difference data of the filter membrane in real - time. During the filtration process, when the filtration resistance of the filter membrane changes due to reasons such as impurity accumulation, blockage, or aging, the pressure difference will change accordingly. This enables the operator to understand the working state of the filter membrane based on the data of the first sensor 23 and intervene in possible abnormal situations in advance.

[0034] The water - oil separation equipment includes an oil collection container 300, and the oil droplets separated by the second filtration unit and the third filtration unit are collected into the oil collection container 300.

[0035] The membrane filtration device 25 can separate the oil droplets in the mixed liquid and effectively precipitate the oil from the mixed liquid. It is connected to the oil collection container 300 through a pipeline, enabling the separated oil to flow into the oil collection container 300 along the channel, realizing the efficient separation and collection of oil and water, and avoiding environmental pollution caused by the discharge of oil - mixed liquid.

[0036] The water - oil separation equipment includes a sand collection container 400, and the sediment separated by the second filtration unit is collected into the sand collection container 400.

[0037] The solid - liquid separation component includes a hydrocyclone solid - liquid separator 11 and a centrifugal separator 12. The upstream side of the hydrocyclone solid - liquid separator 11 is connected to the first filtration unit, and the downstream side of the hydrocyclone solid - liquid separator 11 is connected to the centrifugal separator 12.

[0038] The hydrocyclone solid - liquid separator 11 can initially filter the incoming mixed liquid, filtering out larger - particle impurities such as sediment in the mixed liquid. Through pipeline connection with the sand collection container 400, the filtered sediment can be discharged into the sand collection container 400 in a timely manner, avoiding the accumulation and blockage of sediment in the subsequent treatment process, effectively reducing the sediment content in the mixed liquid, and providing a good water quality basis for subsequent in - depth treatment. The hydrocyclone solid - liquid separator 11 not only has the function of sand removal, but also can be connected to the oil collection container 300 through a pipeline to filter the floating oil in the mixed liquid. During the filtration process, the floating oil and water will separate due to different densities, and the floating oil is collected into the oil collection container 300 through the pipeline.

[0039] In addition, one end of the centrifugal separator 12 is connected to the oil collecting container 300 through a pipeline, and the other end is connected to the sand collecting container 400 through a pipeline, enabling it to further filter the mixed liquid on the basis of the cyclone solid-liquid separator 11. The oil and sediment that were not completely separated by the cyclone solid-liquid separator 11 are filtered a second time. The filtered oil is collected into the oil collecting container 300 through a pipeline, and the sediment is discharged into the sand collecting container 400, improving the separation and collection efficiency of oil, sand, and water, and ensuring that the floating oil and sediment in the mixed liquid are removed to the greatest extent.

[0040] Preferably, a liquid level gauge 401 is provided in the sand collecting container 400. The liquid level gauge 401 is installed on the sand collecting container 400 and can monitor the liquid level height of the sediment in the sand collecting container 400 in real time, reflecting the degree of sediment accumulation. Operators can understand the real-time state of the sediment in the sand collecting container 400 at any time through the data of the liquid level gauge, avoiding sediment overflowing from the container.

[0041] It should be noted that the separation process of the oil-water separation device in this embodiment is as follows:

[0042] 1. Mixed liquid entry stage:

[0043] (1) The liquid containing oil stains and sediment impurities is filtered for the first time. The first filtration uses a mesh bag 500 with a suitable mesh size to filter out large particles such as stones.

[0044] (2) The liquid is pumped out by the water pump 13 and transported to the cyclone solid-liquid separator 11. During this process, a flow meter 14 for calculating the liquid introduction volume, a second oil quantity detector 15 for detecting the oil content of the introduced liquid volume, and a regulating valve 16 for controlling the size of the introduced flow are also provided on the pipeline. It is worth mentioning that, on the connected pipeline, a second pressure sensor 17 for detecting whether the cyclone solid-liquid separator 11 is blocked by upstream sediment is provided upstream of the cyclone solid-liquid separator 11. The second pressure sensor 17 can monitor the pressure value at this position in real time. When the upstream sediment gradually accumulates, the resistance of the mixed liquid flow will increase significantly, resulting in an increase in the upstream pressure. The sensor will capture this pressure change and transmit the data to the control terminal in real time, enabling the operator to detect the possible blockage of the cyclone solid-liquid separator 11 in the first time, so that the operator can intervene at the initial stage of the blockage to ensure the continuous and stable operation of the mixed liquid treatment system.

[0045] (3) When the liquid is in the cyclone solid-liquid separator 11, the principle of the cyclone solid-liquid separator 11 is based on the density difference stratification effect of multiphase fluids under the centrifugal force field. The mixed liquid containing sediment and oil is tangentially injected into the cylindrical section of the separator at a certain pressure. The mixed liquid forms a strong swirling flow field that spirals downward under the guidance of the conical structure. Therefore, under the action of centrifugal force, the sediment with a larger density is thrown to the outer wall surface and spirals downward along the conical section to the bottom outlet; the oil droplets with a smaller density migrate towards the central axis under the combined action of the centripetal buoyancy and fluid drag force, forming an upward inner swirling flow. In this way, the oil droplets, sediment, and water are initially separated. The sediment flows into the sand collection container 400 through a pipeline, and the oil droplets flow into the oil collection container 300 through a pipeline. At this time, a part of the oil droplets are emulsified in the separated water and then enter the next stage of filtration.

[0046] 2. Oil-water separation stage: The mixed liquid enters the centrifugal separator 12, and the mixed liquid is separated again by centrifugal force. The separated oil droplets enter the oil collection container 300, and the water enters the next stage of filtration through a pipeline.

[0047] 3. Filtration stage of the membrane filtration device 25: The mixed liquid enters the membrane filtration device section. Downstream of the membrane filtration device section, there are a first pressure sensor 23, a first oil quantity detector 211 located downstream of the first pressure sensor 23, and a first valve body 212a and a second valve body 212b located downstream of the first oil quantity detector 211. The first pressure sensor 23 is a differential pressure sensor, and the differential pressure sensor is used to monitor the differential pressure in the membrane filtration area. If the differential pressure is too large, the control end issues an alarm to remind the staff to replace the filter screen. The mixed liquid passing through the membrane filtration device 25 needs to be detected for its oil content by the first oil quantity detector 211. If the detection result meets the standard, the control end controls the first valve body 212a to open so that the filtered mixed liquid flows into the clean water pool 100; if the detection result does not meet the standard, the control end controls the second valve body 212b to open so that the mixed liquid flows into the sewage pool 200 and is re-circulated to the upstream of the membrane filtration device 25 through a pipeline for re-filtration.

[0048] It should be noted that a third pressure sensor 18 is provided on the pipeline connecting the cyclone solid-liquid separator 11 and the centrifugal separator 12 to detect whether the pipeline is blocked by oil droplets. The third pressure sensor 18 can monitor the pressure condition in the pipeline in real time. When the inner wall of the pipeline gradually thickens due to oil stain adhesion, resulting in a reduced flow space and an increased water flow resistance, the pressure in the pipeline will change accordingly. The operator can intervene at the initial stage of the blockage problem based on the data of the third pressure sensor 18, avoiding system shutdown caused by complete blockage of the pipeline.

[0049] A third pressure sensor 18 is also provided between the pipeline connecting the centrifugal separator 12 and the membrane filtration device 25.

[0050] In addition, the oil-water separation equipment also includes an intelligent system, and the first pressure sensor 23, liquid level gauge 401, second pressure sensor 17, third pressure sensor 18, etc. mentioned above are all connected to the control terminal.

[0051] Specifically, it also includes: (1) Remote monitoring function. The intelligent network can upload the operation data of the equipment to the cloud platform, and operators can remotely monitor and obtain the operation status of the equipment through devices such as mobile phones and computers. The cloud platform supports pushing alarm information through methods such as WeChat, text messages, and emails.

[0052] (2) Automatic operation. The operation efficiency of the equipment is optimized through fuzzy control algorithms and control terminal control algorithms. Here, the first pressure sensor 23 is used as an example. The control terminal can automatically adjust the operation parameters of the equipment according to the data fed back by the sensor, such as the power of the upstream vacuum pump 22, etc.

[0053] (3) Fault diagnosis and protection. Here, the first pressure sensor 23 is still used as an example. If the data transmitted by the first pressure sensor 23 to the control terminal is too high, then the control terminal automatically takes protective measures, such as shutting down, switching to standby equipment, etc., and it also has the function of recording historical data for some important parameters, which is convenient for tracing and analyzing the reasons when a fault occurs.

[0054] As can be seen from the above, the oil-water separation equipment integrates an intelligent system of sensors (the first pressure sensor 23, liquid level gauge 401, second pressure sensor 17, third pressure sensor 18, etc.) and a control terminal, and can monitor the operation status of the equipment and water quality indicators in real time. The intelligent system optimizes the operation parameters of the equipment through fuzzy control algorithms and control terminal control algorithms to ensure the treatment effect and equipment stability, realizes automatic operation, reduces manual intervention, and improves operation efficiency and reliability.

[0055] In addition, the overall oil-water separation equipment adopts a miniaturized design, which is convenient for transportation and on-site deployment, allows adjustment of the scale according to actual needs, adapts to the floor area and treatment requirements in different environments, makes it have good flexibility and adaptability, and can be quickly deployed to the locations where oily sewage needs to be treated.

[0056] In addition to the above preferred embodiments, the present invention has other implementation manners. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope claimed by the present invention.

Claims

1. An oil-water separation device, characterized in that, It includes a first filtration unit which includes a filter screen for filtering coarse particles; a second filtration unit located downstream of the first filtration unit, which includes a solid-liquid separation component; a third filtration unit located downstream of the second filtration unit, which includes a membrane filtration device; a clean water tank and a sewage tank located downstream of the third filtration unit. The fluid filtered by the third filtration unit is discharged to either the clean water tank or the sewage tank through a diversion unit. The diversion unit includes a main pipeline connected to the membrane filtration device, a first branch pipe connected to the clean water tank, a second branch pipe connected to the sewage tank, and a control valve. A first oil quantity detector is provided on the main pipeline, and the control valve controls the on-off of the first branch pipe and the second branch pipe.

2. An oil-water separation device according to claim 1, characterized in that, The sewage tank is connected to the upstream of the membrane filtration device through a reflux pipeline.

3. An oil-water separation device according to claim 1, characterized in that, It also includes an oil collection container, and the oil droplets separated by the second filtration unit and the third filtration unit are collected into the oil collection container.

4. An oil-water separation device according to claim 1, characterized in that, A first sensor for detecting the pressure difference of the membrane filtration device is provided on the main pipeline.

5. The oil-water separation device according to claim 1, characterized in that, It also includes a sand collection container, and the sediment separated by the second filtration unit is collected into the sand collection container.

6. The oil-water separation device according to claim 5, characterized in that, A liquid level gauge is provided on the sand collection container.

7. The oil-water separation device according to claim 1, characterized in that, The solid-liquid separation component includes a cyclone solid-liquid separator and a centrifugal separator. The upstream side of the cyclone solid-liquid separator is connected to the first filtration unit, and the downstream side of the cyclone solid-liquid separator is connected to the centrifugal separator.

8. An oil-water separation device according to claim 7, characterized in that, A second pressure sensor for detecting whether the upstream of the cyclone solid-liquid separator is blocked by sediment is provided on the pipeline connecting the cyclone solid-liquid separator and the first filtration unit.

9. An oil-water separation device according to claim 7, characterized in that, A third pressure sensor for detecting whether the pipeline is blocked by oil droplets is provided on the pipeline connecting the cyclone solid-liquid separator and the centrifugal separator.

10. An oil-water separation device according to claim 1, characterized in that, The control valve includes a first valve body and a second valve body; alternatively, the control valve is configured as a two-way fluid switching valve and is provided at the intersection of the main pipeline and the first branch and the second branch.

Images