Cavitation air floatation Machine(CAF)

I. Overview of Vortex-Concave Air Flotation Machine

1. Use of THAF Vortex Concave Air Flotation Machine

THAF Vortex-Concave Air Flotation Machine is the core product of our company. It is specially designed to remove grease, colloid and suspended matter from industrial and urban sewage. Since its establishment in 1995, Qingtian Company has produced nearly 1,000 vortex-concave air flotation machines of various specifications, which have been applied in sewage treatment fields all over the country, achieved good results, and have been exported to many foreign countries and regions. Among them, the matching vortex aerator is a patented product of our company (patent number: ZL98 2 21723.4). THAF Series Vortex Air Flotation Machine was listed as the national key environmental protection practical technology in 2009 by the State Environmental Protection Administration, and obtained the environmental protection product approval certificate of Shandong Environmental Protection Bureau. According to different wastewater, the removal rate of suspended solids (SS) and grase in the vortex-concave air flotation machine is as high as 95%, and other wastewater indexes also decrease in different degrees. In addition, after adding appropriate chemicals and mixtures to the equipment, COD and BOD can be removed by more than 40% in this pretreatment stage, which is a significant technological revolution to the traditional dissolved air flotation with low equipment operation cost, high work efficiency and simple operation and maintenance.

The vortex-concave air flotation machine produced by Qingtian Company has mature technology, stable performance and reliable quality. Its products are available to major environmental protection design companies, engineering companies and end users, and the price is real and the quality s reliable. THAF Vortex Concave adapts to industries: paint, leather making, oil refining, printing and dyeing, chemistry, dairy processing, fiber production, paper making, food, beverage, slaughter, textile, mechanical processing, municipal sewage.

Air flotatin is the primary treatment in sewage treatment, which belongs to the category of physical treatment. Air flotation machine can only remove most (up to 99%) of suspended matters and a small part of COD and BOD. Strictly speaking, the treated water can't be directly discharged and can't reach the standard, so it can only be used as the pretreatment of secondary and tertiary biochemical treatment. However, in the sewage treatment project, if there is no pretreatment, the raw water will not enter the biochemical treatment process, or it will cause great load to the biochemical treatment process. Therefore, pretreatment is a necessary step in sewage treatment, and the result of pretreatment is directly related to the effect of subsequent biochemical treatment. Therefore, the air flotation machine is an essential universal environmental protection equipment in sewage treatment. In some simple sewage treatment systems, sewage can be directly discharged into the urban pipe network for centralized treatment after sedimentation, air flotation and filtration. It depends on different water quality conditions and requirements of different regions.

THAF vortex-concave flotation can not only help us to treat sewage to the biochemical standard range, but also greatly reduce the subsequent operation cost. Another important aspect is that the by-products produced in wastewater treatment can often be recovered, recycled and sold. For example, in the paper industry, the pulp collected by the air flotation slag scraper can be recycled.

2. Advantages of THAF series vortex-concave air flotation machine

A. Save investment

THAF Vortex-Concave Air Flotation Machine can remove grease, suspended solids, BOD and COD in sewage. Installing this equipment in front of the biochemical secondary sewage treatment plant can greatly reduce the scale of the treatment plant, thus greatly reducing the overall investment cost. Vortex flotation machine does not need pressure vessel, air compressor, circulating pump and dissolved gas release equipment, thus greatly reducing the investment cost of sewage pretreatment.

B. Low operating cost

The whole vortex-concave air flotation machine only needs the power of a few ordinary motors. Low energy consumption, which can't be compared with other air flotation machines. And the maintenance and manual operation are minimal.

C. High efficiency

Contrary to the traditional grease collectors (gravity settling tank and separation tank), the vortex-concave air flotation machine automatically and continuously removes solid sludge from wastewater. The removal and storage of sludge are carried out in a concentrated way, thus reducing the cost of sludge treatment.

D. Simple operation

THAF Vortex-Concave Air Flotation Machine is very easy to operate, and there is no complicated machinery and equipment at all, nor does it need human participation. The whole main machine part consists of only two mechanical parts (aerator and slag scraper), unlike dissolved air flotation machine, which includes many necessary equipment such as pressure vessel, air compressor and circulating pump. And the vortex-concave air flotation machine can be used after installation without debugging or calculating the mixing ratio of air and water.

E. Good working environment

The treatment of wastewater by THAF flotation machine is an aerobic process. The odor problem caused by the original grease collector (gravity settling tank and separation tank) has been well solved. On the other hand, the power of the equipment is very small, and there is only slight motor noise during operation, so there is no noise pollution.

F. Economic benefits

THAF flotation machine has simple design, good matching, and less civil works for the machine, which is very attractive from the investment point of view. Because of its simplicity and integrity, it can be installed on the ground, underground or high, and it takes very little time.

II、 the structure and working principle of vortex-concave air flotation machine.

1. Machine structure of vortex-concave air flotation machine

The whole air flotation machine host system consists of five parts:

a)   Flocculation coagulation zone

b)   Aeration zone

c)   Separation part of flotation machine (standard chain scraper)

d)   Scum collecting tank (self-flowing or optional screw-type solid discharger)

e)   Clear water discharge area (standard handwheel water level regulator)

Note: The front end of the air flotation machine needs to be equipped with a dosing system. At present, domestic air flotation machines commonly use the combination of flocculant PAC and coagulant aid anion PAM (for details, please refer to the instructions of liquid medicine configuration in the annex).

If there is no dosing system at the front end of the air flotation machine, the air flotation effect will be greatly affected, and the equipment can play a greater role with the cooperation of flocculants. It is recommended to use the dosing system. Unless in some special areas, such as just degreasing or oily paint (floating state originally), direct operation without dosing system can be considered.

2. Working principle and process of vortex-concave air flotation machine

The sewage pump lifts the untreated sewage into the coagulation and flocculation tank at the front end of the air flotation machine (if conditions permit, it can also flow into the air flotation machine by itself). It is suggested to set the PAC dosing port in front of the sewage lift pump, so that the PAC liquid medicine can be more fully mixed in the sewage through the high-speed rotation of the impeller of the lift pump. Of course, the PAC dosing port can also be set on the sewage inlet pipe, and it is recommended that it be on the pipe 30-40m away from the air flotation machine, so that the effect is better. The farther the dosing nozzle is from the main machine, the more fully the liquid medicine and sewage can be mixed and reacted.

     At the water inlet of each air flotation machine and the flocculation tank, we set a connecting thread head of the dosing pipeline. However, we don't recommend adding PAC liquid medicine here. The two liquid medicine adding points are only for standby, so it's really impossible to find the adding position far away from the main air flotation machine. Then consider the adding point at the water inlet. The two dosing points can be used as PAM dosing points. It is recommended to use the dosing point in the flocculation tank (the nearest dosing point to the aeration tank).

Mixing with sewage PAC and PAM in flocculation tank can adopt mechanical agitation or baffled flow, both of which have their own advantages and disadvantages. Users can choose the type according to the actual situation. Mechanical stirring type is equipped with two mixers, the rotating speed of which is mostly 30-60RPM, which can mix well, but it consumes energy, and there may be mechanical failures in operation, resulting in high cost. Baffle flow mostly uses three cavities to baffle back and forth, without mechanical equipment and cost, but the mixing effect is not as good as mechanical stirring. However, in some sewage fields, the use of mechanical stirring may break flocs, which is more unfavorable to air flotation.

After mixing and reacting with sewage flocculant, it enters the aeration box equipped with aerator. Vortex aerator is the key equipment of air flotation machine, and its performance directly affects the effluent effect of air flotation machine. The sewage enters the aeration tank from the bottom (the water inlet is above the impeller of the aerator to prevent flocs in sewage from being broken by the impeller rotating at high speed).

And sewage flocs gradually rise along with the water flow in the aeration tank, and are fully mixed with the tiny bubbles generated at the impeller of the vortex aerator. In the floating process, the tiny bubbles will adhere to the suspended solids, and when they reach the water surface, the solid suspended solids will be supported and maintained by these bubbles and float on the water surface of the air flotation separation area.

The working principle of the concave aerator is to use the high-speed rotation of the impeller at the bottom of the aerator main shaft (air conveying pipe) to form a vacuum area at the lower part of the aerator box, so that the air on the liquid surface of the aerator box is continuously sucked into the water vacuum area through the aerator main shaft to fill the gap, and is broken by the high-speed rotating impeller, forming tiny bubbles (with diameters ranging from 30um to 2-3mm, mostly tiny bubbles below 1mm). In the process of rising, microbubbles adhere to flocs such as suspended solids, forming a gas-water mixture.

Due to the imbalance between the gas-water mixture and the liquid, a vertical upward buoyancy is generated, and the suspended solids are brought to the water surface under the action of buoyancy and water flow.

The suspended solids floating on the water surface move from the front end of the separation area to the back end driven by the water flow and the scraper of the slag scraper. The slag scraper is driven by the sprocket drive driven by the stepless speed regulator. The scraper is connected to the chain, and driven by the chain, it moves along the whole liquid surface, scraping the pollutants onto the inclined metal plate (saddle plate), and then pushing them into the slag collecting tank. According to the length of air flotation equipment, multi-page scraper can be configured to ensure timely slag scraping. However, if there are too many scrapers, the chain will be burdened and the failure rate will increase. The speed of the stepless governor can be adjusted within 8-40 revolutions, and it is recommended that the speed be 12RPM (the running linear speed is about 2m/min). Therefore, the proper number of scrapers, proper running speed, and proper slag scraping interval are the keys to ensure the effective operation of the slag scraper.

Most of the slag collecting tanks are designed to be self-flowing, and the height difference at both ends is greater than 400mm, which can ensure that scum can be discharged out of the box smoothly. If the scum density is very high and the fluidity is poor, a screw slag extractor can be arranged, and the horizontal screw hinge can be used to discharge the scum in the slag collecting tank out of the box. The discharged scum can enter the sludge pond or directly into the sludge dewatering equipment for further treatment. If the air flotation equipment is installed overhead on the sludge tank, it can also be drilled in the middle part of the sludge collection tank and directly discharged into the sludge tank at the bottom of the air flotation machine by pipeline, which is more convenient.

Before being discharged, the purified sewage will first pass through the baffle at the back of the air flotation box, and then flow into the overflow trough from below the baffle. A hand-wheel type liquid level regulator is arranged between the overflow tank and the clear water tank to control the water level in the air flotation tank, so as to ensure that the liquid in the air flotation tank will not flow into the slag collection tank.

III. Technical Parameters and Type Selection of Vortex Air Flotation Machine

1. Equipment selection basis:

Because each project has different sewage treatment schemes and processes, different influent water quality and different effluent requirements, users are advised to consult the manufacturer directly if they want to choose the type. If type selection is required, users need to provide the following information:

（1） Sewage treatment capacity: how many tons of sewage should be treated per hour?

（2） Nature of sewage: for example, domestic sewage, food processing industry, printing and dyeing industry, machinery manufacturing industry or other industries (specific to what products and industries are produced).

（3） Sewage inflow index: especially SS, grease, COD, BOD, etc.

（4） Flow direction of effluent: it is best to provide the process diagram of the whole project. If not, please inform the flow direction or purpose of effluent (recycling, biochemical treatment, filtration or urban pipe network, etc.).

（5） Effluent indicators: especially the indicators of SS, grease, COD, BOD, etc.

（6） There is no limit to the site where the equipment is installed; Whether it is installed indoors or outdoors;

If so, what is the length, width and height of the available site?

Users should provide the above information as much as possible. If they can't provide it, we can also make reasonable selection and layout according to the current data and general standards, and make a quotation.

2. Data sheet of general equipment selection (please consult the manufacturer if necessary)

Note: (1) As this equipment belongs to non-standard equipment, the size of the equipment, the size and position of the water inlet and outlet can be adjusted as required. The above parameters are for reference only.

(2) The above selection parameters are not recommended for non-professionals to use. Environmental protection companies or professional and technical personnel can refer to the above parameters and water inlet and outlet requirements for reference.

(3) If you need accurate type selection, please contact Li Gong 13791840500, a technician of Qingtian Company, for consultation or technical exchange.

3. Operating parameters of equipment

(1) The maximum sewage treatment capacity of a single device is 200m³/h.

(2) The minimum sewage treatment capacity of a single device is 0.5m³/h.

(3) The rotating speed of the main shaft of the vortex aerator is 1450r/min, and the power of a single unit is 1.5-2.2kw.

(4) The speed of the speed reducer of the slag scraper is 8-40 revolutions per minute, the linear speed per minute is 2.0m-20m/min (stepless speed regulation, adjustable speed), and the power is 0.37-0.75kw

(5) The screw propeller speed of the slag extractor is 127r/min, and the power is 0.37-0.75kw. (optional, most of them are designed to be self-flowing)

(6) Equipment motor and distribution box: stainless steel rainproof design of electric control box, 380V, three-phase four-wire system. Standard local control box, no other conditions. If required by the user, manual automatic control switching can be realized as required (under manual control, the start and stop of each motor can be controlled manually, and under automatic state, all the motors can be started and stopped according to the start and stop of the water inlet pump or water flow signal), and PLC local or remote control can also be realized according to the requirements for use.

The type of motor and electric cabinet can also be explosion-proof according to user's requirements, or the protection level is IP56 (standard is IP55), and the energy efficiency level is IE3 or IE4 (standard is IE2).

In case of non-special circumstances (explosive industry or requirements of bidding documents, etc.), it is not recommended to use high-configuration equipment, which has high cost, long delivery period and high maintenance and repair cost.

IV. Installation, operation and safety of the machine

1. Installation of the machine

(1) Before the machine leaves the factory, the aerator, screw type slag scraper (optional), chain type slag scraper and electric control box have been installed on the air flotation box, and they have been debugged normally. Users generally don't need to adjust themselves, including the big chain. Before the whole machine leaves the factory, all gearboxes have been filled with lubricating oil, so there is no need to add it again.
    Before the equipment is installed, the foundation must be tamped. And the concrete mortar pad is 100-150mm high. It can also be installed overhead, but the foundation must be able to bear the weight of the equipment during operation.

After the equipment is in place, it is necessary to adjust the level to ensure that the whole machine is on a horizontal plane, otherwise the equipment will have uneven scum after entering the water, which will make it difficult to scrape the slag, and the liquid level cannot be guaranteed at the same height.

After the whole machine is moved to the designed position and leveled, there is no need to fix it by anchor (if it is installed underground in special circumstances, it must be fixed by anchor). Just connect the inlet and outlet pipes and drain pipes respectively, and then connect the input pipes of dosing equipment such as coagulant and flocculant (some projects may require three or more kinds of reagents). Finally, connect the motor power cord (three-phase four-wire) in the electric control box, and the installation of the whole machine is over.

(2) During the operation of the equipment, water (foam) may overflow the site due to improper operation and other reasons, and the equipment may need to be cleaned after long-term operation. Therefore, it is necessary to set a sewer for cleaning, open channel can be dug, or it can be directly connected to the regulating pool by pipeline, so as to flush the air flotation equipment or the overflow water can be discharged in time.

It is best to have separate drainage facilities for the installation of sewage treatment equipment, but this is not a necessary condition for the operation of the equipment. Users can choose according to the actual situation.

(3) The clear water outlet can be connected to the sewer for discharge. If you need to enter the next treatment process, you can directly connect with the next treatment equipment. Pay attention to the drop when flowing. If the drop can't meet the requirements, a high-altitude air flotation machine can be installed or the next treatment equipment can be lowered, or it can flow to the middle pool by itself, and then the fresh water pump in the middle pool can be pumped to other treatment units.

(4) The scum outlet can be connected to the sludge pond or sludge treatment equipment (such as screw stacker, plate frame or belt conveyor, etc.). Pay attention to the drop when you drift. If the drop can't meet the requirements, a high-altitude air flotation machine can be installed or the next treatment equipment can be lowered, or it can flow to the intermediate sludge pool by itself, and then it can be pumped to other treatment units by the sludge pump in the intermediate pool.

(5) Several sewage outlets at the bottom of the air flotation tank can be connected to the regulating tank or sludge tank or sludge treatment equipment (according to the process flow chart). When the air floatation machine is in normal operation, the valve of the sewage outlet is closed, and this valve is only opened when the air floatation machine is cleaned.

(6) The electrical box of the air floatation machine has been fixed on the side of the air floatation machine, and the environment should be clean, clean and dry. If the electric cabinet is placed separately, this standard should also be referred to.

2. Preparation before equipment operation (commissioning status)

(1) Prepare the liquid medicine in advance (please refer to the liquid medicine preparation instructions).

(2) Check whether the air flotation tank and dosing box are cleaned (be sure to clean them);

(3) Check whether each valve is flexible and easy to use, and whether the emptying valve of each pool is closed (be sure to close it);

(4) Check whether the chain and bearing of the slag scraper are well fixed, the bolts and jacking wires are not loose, and the positions of the four sprockets form a rectangle (be sure to be a rectangle); Whether the exhaust nozzle of the speed reducer of the slag scraper (located at the upper part of the handle) is open (be sure to loosen it) to prevent the speed reducer from being damaged due to excessive internal temperature.

When leaving the factory, the whole slag scraper has been debugged, but in the process of transportation and hoisting, the fixing bolts or jacking wires of the bearing and sprocket of the slag scraper may become loose, so it must be checked again before the first operation. Make sure that the four sprockets of the slag scraper form a rectangle instead of a parallelogram. If any deviation is found, it must be adjusted in time.

The position of the scraper chain wheel and the bearing seat on the shaft can be fine-tuned. Loosen the jacking wire and gently knock it with a hammer, which will move the position. After moving to the appropriate position, the jacking wire must be fixed. During commissioning and normal operation, the fixed jacking wire of each bearing seat and sprocket must be tightened, otherwise, the position deviation will easily occur during operation, resulting in the damage of the chain or scraper. It is recommended that the equipment should be checked one by one before commissioning and operation! !

(5) Whether the connecting bolts of each part are loose, and whether the pipes and pipelines are connected normally;

3. Commissioning of the equipment (commissioning status)

(1) When commissioning, it is strongly recommended to use clean water commissioning, and reuse sewage when conditions are really not allowed. First, open the sewage inlet pipe valve;

(2) then open the chemical additive input valve (PAC before PAM);

(3) when the water level in the air flotation box rises to a half position, the vortex aerator is started;

 At this time, pay special attention to the fact that if there are not a lot of microbubbles floating up, it means that the connection direction of the power supply is reversed, so please immediately change the direction (any two-phase line can be replaced in the three-phase line). In normal state, the rotating direction of the main shaft of aerator is clockwise (the direction of the red arrow on the equipment).

(4) When the solution in the air flotation tank reaches about 2-3cm from the highest point of the saddle plate, restart the chain slag scraper and screw slag remover (optional); If the liquid level does not reach the height of 2-3cm, the water will come out of the water outlet, and the water level can be adjusted by the hand wheel type water level adjusting device. When the air flotation machine is running normally, the water level height is about 2cm away from the highest point of the saddle plate.

If the running directions of chain slag scraper and screw slag remover (optional) are opposite, the running direction can also be adjusted by adjusting the wiring.

If the scraper of the slag scraper does not extend into the scum, or it is very shallow, the first solution is to raise the water level (but the water level cannot overflow the highest point of the saddle plate, and the normal distance from the highest point is about 2cm). The second solution is to loosen the bolts on the rubber of the scraper one by one, and the rubber can be pulled out or retracted to adapt to the water level. After pulling to the appropriate position, the bolts must also be fixed (the adjustable range here is about 2-3cm).

(5) At this point, the equipment starts to run. The biggest advantage of the concave air flotation machine is that there is no need to adjust the aeration rate. The only thing that can be adjusted is the dosage (the location of the dosing point is adjusted when the equipment is installed). During commissioning, the dosage can be implemented according to the following standards: the dosage of PAC 5% and PAM 0.2% is 8L per ton of water. For example, if the water inflow is 50T/H, the dosage will be 400L/H, and then it will be gradually reduced according to the effluent effect. In normal operation, the dosage of the flotation machine is about 3-5L per ton of sewage, but it may reach 10L at the maximum depending on the water quality and other factors. Please refer to the attachment "Instructions for Liquid Preparation and Commissioning".

(6) When the air flotation equipment is turned off, the dosing system can be turned off first, then other equipment of the air flotation machine can be turned off, and finally the power supply can be cut off. Attention should be paid to prevent the liquid medicine in the dosing system from flowing backwards, so that the sewage in the air flotation box can enter the dosing box. It is necessary to add a check valve when installing the dosing pipeline or the dosing pipeline is higher than the floating water level (if dosing is done with a metering pump, the metering pump itself has a check valve).

4. Normal operation and precautions of air flotation machine

(1) When commissioning, the above starting procedures should be carried out in turn and cannot be reversed. During normal operation, because the air flotation case has been filled with water, the related supporting equipment can be started randomly, which has little impact.

(2) The equipment can be unattended during normal operation. During patrol, closely monitor the operation of each motor and pump;

Always check the motor temperature to ensure it is within the normal range.

(3) Because the water quality may be unstable, such as the difference between day and night, the difference between seasons in a year, and the difference after the adjustment of production technology, the influent water quality will be different, so it is necessary to adjust the dosage of various chemicals at any time to achieve the best effect of air flotation;

(4) Always check whether the chain and bearing of the slag scraper are loose. Because of the tension during operation, the chain and bolts of the new machine will be loose after 3-5 days of normal operation, so it needs to be adjusted twice. After about 15 days of operation, it needs to be adjusted for the third time. If there is no damage in the later period, it basically doesn't need to be adjusted, but always pay attention to the operation of the slag scraper system during inspections to prevent the chain from falling off. You can adjust the tightness of the chain by installing the tensioning device or the motor to adjust the long hole. The chain of slag scraper and the transmission chain of reducer should be adjusted.

(5) Regularly check the liquid level of the medicine storage box to ensure the timely supply of medicines; If a single barrel is used for dosing, when the remaining third of the liquid medicine is used, the liquid medicine must be prepared in advance. The PE dosing tank will give an alarm when one third of the liquid medicine is left, and the pump will be stopped when there is no liquid medicine (there may be no such settings here according to the actual situation, and if not, the staff should pay attention to summarizing the interval time of configuring the liquid medicine). If the magnetic pump or metering pump is idle for a long time, the internal seal and other parts will be seriously damaged, resulting in fever and burning out.

（6）   If the equipment is equipped with a slag storage tank, the liquid level of the slag storage tank should be checked frequently, and when the liquid level reaches 80%, the relevant personnel should be informed to load the vehicle, so as to prevent the scum from overflowing and causing the overall environmental pollution.

（7）   The floating pool should be cleaned regularly depending on the amount of sediment. There is no limit to the interval here, and it must be carried out according to the actual situation. It is forbidden to have sundries in the medicine box to prevent the pipeline of the metering pump from being blocked;

(8) The aerator must run in a positive direction, and it is forbidden to open the aerator when there is no water in the pool. The aerator is equipped with a mechanical sealing device at the bottom, so it can work only if it is cooled by water. If no water passes through, it is forbidden to drive! So as to avoid equipment damage accidents.

（9）   It is strictly forbidden to adjust the speed of the stepless speed regulator of the slag scraper without electricity (static). The motor should be started before adjustment. Forced speed regulation will cause damage to the speed regulating handle.

5. Safe operation

(1) The high-speed running parts of the machine are all designed and installed inside, which is safer. When the equipment is in operation, the operator should wear overalls when observing it, so as to prevent the exposed chain from twisting into the sprocket and causing danger. During normal operation, the chain must not be wiped by hand, and when lubrication is needed, it should be stopped and refueled. Remember. The running screw propeller (optional) can't be manually operated. If something falls into it, stop immediately and take it out.

(2) When tightening the chain of the slag scraper or adjusting the scraper, it must be adjusted after stopping the machine. Second, it must be skid-proof. The pollutants in the sewage adhere to the casing or the slag scraper, which is sticky and slippery, so as to prevent falling into the pool and hurting yourself. When working, it's best for two or more people to walk together to take care of each other.

V. Maintenance and maintenance of air flotation machine

1, the machine should pay attention to maintenance, normal operation and operation according to the requirements of Item 4 of Article 4 above. If there is a fault, it should be eliminated in time, and it must not run with illness. If the user has the conditions, it is best to install the equipment indoors or build a simple working shed above it, otherwise, in rainy and snowy weather, scum will be broken by rain and it will not work normally. During the operation of the equipment, because it is an aerobic process, there is no rancid odor (unless the raw water has an odor). However, in some areas, the environmental protection requires that the sewage treatment facilities must be managed in a closed manner, so users can install a glass fiber reinforced plastic cover on the top of the air flotation tank, or make a request during production, and we can take sealing measures as required. Secondly, attention should be paid to heat preservation in winter in northern China. Heat preservation measures should be taken for water inlet and outlet pipes, return pipes and dosing pipes, and heat preservation cotton pipes should be installed or wound with electric tracing.

2. The running-in period of the machine is one month, and the chain and tensioning device (including the driving chain and the slag scraping chain) should be adjusted in time according to the above-mentioned Article 4-4. Enter the normal operation period after the running-in period.

3. Under normal operation, the reducer gearbox should be oiled once every three months to keep the oil level high. The stepless governor of slag scraper uses special synthetic oil of stepless governor (preferably traction fluid Ub-1 and Ub-2), and the first oil change time is 500 hours. It is recommended to change the oil every six months.

Other flocculation and dosing reducers use N320 lubricating oil. The amount of all decelerating oil should exceed half of the oil standard, and it should be supplemented if it is lower than the oil standard. It is recommended to change the lubricating oil every six months. There are many markets for the above two kinds of lubricants, which can be purchased at local lubricant sales offices.

4. Drives roller chain of slag scraper, and drops 20# machine oil once a month with oil gun, with appropriate amount. The stainless steel chain of slag scraper can be inspected according to the daily routine. If it is found that the chain is loose or wandering or there are signs of broken chain, it should be stopped in time to find out the cause of the failure and solve the problem from the final cause. Early detection can avoid greater losses. If it is not found in time, it may not only be the failure of the chain, but also the damage of the reducer and scraper.

5. Add lithium-based 3# grease to the rolling bearing in the bearing seat of slag scraper of air flotation machine once every eight months. Each bearing seat has a special oil injection hole, which can be directly injected with an oil gun.

6. The air flotation tank should be emptied regularly depending on the amount of sediment. If the floating water is always clear, and after a period of time, the floating water contains suspended matters, it means that the floating pool should be emptied and cleaned. After the equipment runs normally, the interval of regular cleaning can be summarized. Open the drain valve and drain the sludge from the bottom of the pool. If conditions permit, the bottom of the pool can be washed with slightly clean water, which will be more thorough.

7. The air flotation case should be maintained every two years and treated with internal and external anti-corrosion treatment (after the internal and external parts are cleaned, marine asphalt epoxy anti-corrosion paint can be used inside, epoxy primer and epoxy finish or acrylic acid finish can be used outside, or local anti-corrosion company can be consulted to adopt more advanced anti-corrosion measures). If properly used and maintained, the service life of this machine will be within 20-25 years.

VI. Daily inspection

1, pay attention to observe the pool surface during inspection:

If it is found that the scum surface in aeration area is uneven and the local water flow churns violently, it may be that the impeller of aerator falls off and needs to be checked and replaced in time.

If it is found that the scum surface in the separation area is uneven and large bubbles often bulge on the pool surface, this indicates that the adhesion between bubbles and impurity flocs is not good, and it is necessary to adjust the dosage or change the type of coagulant.

If it is found that there are no tiny bubbles floating in the aeration area or suddenly there is no floating effect (no scum, dirty effluent), it may be that the main shaft of the aerator is blocked, and it is necessary to stop the machine for inspection and dredging.
    2. When the coagulation effect is affected by the low water temperature in winter, in addition to the measures of increasing the dosage, it is also possible to increase the number of microbubbles and the adhesion of flocs by reducing the water inflow, so as to make up for the lowering of the floating performance of aerated flocs due to the increase of water flow viscosity and ensure the effluent quality.
    3. In order to ensure the quality of the effluent, we should pay attention to accumulating operating experience, summarizing the best thickness and water content of scum, and reasonably adjusting the speed of the slag scraper to scrape the scum. If there is a regular slag scraping function in the electric control box, we can establish a slag scraping system according to the amount of slag.

4. Adjust the dosage of coagulant in time according to the flocculation of the reaction tank, the scum in the separation area of the air flotation tank and the changes of the effluent quality, etc. At the same time, always check the operation of the dosing pipe to prevent blockage (especially in winter).

Address: Wangtai Town, West Coast New District, Qingdao

Tel: 13791840500        0532-83131543

Zip code: 266425

E-mail: qdqingtian@163.com