How to place the decanter?
- The centrifuge must be placed on a horizontal and solid base (the installation diagram of the centrifuge provided by our company only illustrates the dimensions of the plane arrangement). The concrete base with pre-built parts is poured according to the provided installation diagram, and its structural strength is determined by the actual load required by the user, which should be able to withstand the total weight of the centrifuge and the dynamic load of operation (vertical dynamic load is calculated by 1.5 times of static load, the horizontal dynamic load is calculated by 0.5 times of static load), and be isolated from the vibration generated by other equipment.
- When the machine arrives, adjust the position as required and weld the shock absorber mounting plate under the machine body with the corresponding pre-built parts. Users can also adopt steel structures or other forms of base according to their needs. However, when using a steel structure base, special attention should be paid to the fact that even if the steel structure base is strong enough, resonance will occur when the vibration frequency of the centrifuge is the same as the inherent frequency of the steel structure. Therefore, it is recommended to avoid this method, and if a steel structure must be used, the support feet of the steel structure must be below the vibration damper of the centrifuge. When installing centrifuges on an elevated steel structure, sufficient reinforcing steel should be added. When installing multiple centrifuges on a steel structure, the steel frame of a single centrifuge should be ensured to be in an independent state and the steel foundations should not be connected together to prevent resonance problems of the equipment. The level of shock absorber of concrete foundation and steel structure foundation should be ensured within 1mm/m.
- Conventional centrifuge schematic
How to install the decanter？
- In order to facilitate maintenance, it is necessary to set up lifting equipment that meets the lifting requirements.
- When lifting, hang the sling firmly with the sling bag ring and the special ring on the machine base, do not hang the sling in other parts, and the angle formed between the two slings shall not be greater than 90°.
- All coupling parts of the machine and valves, etc., should be fully considered for safe and easy operation. There should be sufficient reserved space or access around the equipment. Particularly, it is important to consider that there is enough space around the drum assembly and spiral assembly to facilitate disassembly and placement. Make sure that there is space around the centrifuge to pull out the feed tube.
- Place the centrifuge on the base according to the correct position, and adjust the position of the centrifuge with each auxiliary equipment and pipeline interface. After checking according to the relevant technical requirements, you can weld the base plate of the shock absorber with the relevant pre-buried parts (you can weld several places in sections). The welding of the shock absorber and the pre-buried parts of the foundation is shown in diagram II.
- The operating temperature of the equipment should be controlled between 5℃ and 40℃. Equipment should be avoided to contact with strong corrosive substances and be arranged indoors.
- When checking whether the machine is placed horizontally, the upper plane of the machine base (guide rail) should be used as the reference (horizontal requirement: length direction should not exceed 0.2mm/m, width direction should not exceed 0.2mm/m.) If the standard is exceeded, you can loosen the connecting bolt between the machine base and the shock absorber, lift the machine, and add or remove the adjustment shim on the top of the shock absorber to achieve horizontal placement.
- Shock absorber and foundation connection diagram
Connection to process piping
- The centrifuge is high-speed rotating equipment, with a certain frequency of vibration, any external force will deteriorate the working condition of the machine. It is required that all pipelines and facilities to be connected with the machine should be connected in a flexible way that can be retracted near the machine body.
Connection of feed pipe
- The feed to the centrifuge is preferably conveyed by a volumetric pump (1-to-1 mode is required, i.e., 1 feed pump controls 1 centrifuge, frequency converter control), and the start/stop of the feed pump is required to be interlocked with the centrifuge. The pressure at the inlet of the centrifuge feed pipe is about 0.05 to 0.3 MPa (related to the feed volume), and a flow meter is set up on the centrifuge inlet feed line to confirm and control the flow. A flushing water line is provided to flush the drum and spiral of the centrifuge, as well as the inner cavity of the machine base. The number of flushing water lines varies according to the material characteristics and process requirements, as detailed in the centrifuge installation base drawing.
- The feed pipe and the process feed line should be connected with a metal mesh hose connector, and leave space for disassembly and installation of the feed pipe.
Connection of solid-phase discharge outlet
- The flange (square) that comes with the machine can be installed on the body, and the lower end can be connected to the slag storage tank (or the inlet of other conveying equipment such as screw conveyor) through a flexible joint, or a non-contact open-end type can be used to receive the material.
Connection of liquid-phase discharge outlet
- The liquid collection hopper that comes with the machine can be used, and the pipeline is laid on-site according to its installation location. The size of the pipe diameter should ensure the smooth flow of water, avoid right-angle bends, and connect with the discharge pipe through soft joints. The diameter of the pipeline and the installation slope must meet the requirements of the maximum processing capacity of the machine.
- Other pipelines connected to the machine should have flexible connection devices near the body.
Acceptance of installation works
- After the installation project is finished, the relevant personnel should be organized to check the whole project carefully according to the technical standards and agreements, and those that fail to meet the requirements should be thoroughly rectified until they are qualified. The inspection mainly includes the following aspects：
- Whether the installation is correct (including fixing method, level, installation position, etc.).
- Whether the conveying method is reasonable.
- Check that the centrifuge transport support bolts (2 in total) are removed before starting the machine, that the support bolts are located directly above the bearing housing, and that they are replaced with the bolts (M 16, length not exceeding 40 mm) that came with the machine.
- Whether the connection between the centrifuge and all parts is safe and reliable, and whether the import and export of the centrifuge are adopting flexible connection.
- Whether the slag outlet and liquid outlet are clear.
- Whether the drive belt and safety cover are correctly installed.
- Whether the motor steering is correct (from the differential input shaft end, the drum rotates counterclockwise, or can be determined by the rotation pointing plate on the machine).
- Whether the lubricating oil, lubricating grease, oiling gun is equipped completely.
- Whether the electrical system is set correctly for each parameter value.
- Whether the equipment protection detection devices (if equipped with vibration sensors, bearing temperature sensors, etc.) are connected, reliable and effective.
- Whether the interlock control of the auxiliary equipment of the centrifuge is perfect, for example, the interlock of the feed pump opening and stopping with the centrifuge (when the centrifuge is stopped, the feed pump automatically stops feeding); the interlock of the flushing water valve switch with the centrifuge (when the centrifuge is stopped, the flushing water valve automatically opens), etc.
What are the requirements for the installation environment of the control cabinet?
- In order to ensure the stable and reliable operation of the components in the control cabinet, there are specific requirements for the installation of the control cabinet as follows:
- When installing, it should be installed in a place where it can bear the weight of the control cabinet, otherwise, there is a risk of injury or damage when it is dropped.
- It is strictly forbidden to install on the occasion where water drops may be generated from water pipes, etc., otherwise, there is a risk of injury or damage.
- Avoid installing it in places where there is oil mist, metal dust, and much dust.
- Avoid installation in harmful gases, liquids, and corrosive occasions.
- Non-explosion-proof type control cabinet should be installed in a non-explosion-proof area.
- Do not install in direct sunlight.
- Do not drop the drilling residue into the control cabinet, especially the components inside the control cabinet (such as inverter, PLC, air switch, etc.) during installation, otherwise, there is a risk of damage to the device or even electric shock.
- Please install the control cabinet vertically and keep the site environment well ventilated to facilitate the heat dissipation of the inverter inside the control cabinet, it is recommended to install a cooling fan or air conditioner on-site to keep the ambient temperature from rising above 45℃.
- Install in a place where the vibration is less than 5.9m / s2 (0.6g).
Precautions when handling control cabinets
- When handling, do not let the control cabinet panel under pressure, otherwise, there is a risk of injury or damage when falling.
- When lifting, hang the sling and control cabinet ring (diagonal ring) firmly, do not hang the sling in other parts, the angle formed between the two slings shall not be greater than 90°, the lifting process requires a smooth, light lifting, no vibration, and touching phenomenon, please refer to the control cabinet lifting schematic.
Installation of the electrical system
- In the motor wiring, the user should fully consider the motor starting current and full load working current requirements of the wire, and choose the appropriate wire diameter for configuration. And at the same time take into account whether the wire environment around the wire has special requirements for the wire.
- The installation of the control cabinet should follow the principles of easy operation, easy observation, and easy maintenance. The arrangement of all devices in the cabinet should be strictly in accordance with the specifications. Check carefully against the electrical control diagram before connecting. Be connected only after two or more people have confirmed that it is correct.
- All parts that may come into contact with the human body (or are required by design) should have a reliable grounding protection device.
- Disassembly or adjustment of the machine is not allowed without cutting off the power supply.
- For other requirements, please refer to the "electrical control manual" and the national technical standards and technical specifications on electrical aspects that are suitable for this machine.
Acceptance of installation works
After the installation works are finished, the relevant personnel should be organized to inspect the whole work carefully according to the technical standards and agreements, and those that fail to meet the requirements should be thoroughly rectified until they are qualified. The construction department should provide complete completion information to the using department. The inspection mainly includes the following aspects:
- Whether the installation position is correct.
- Whether the cable meets the requirements.
- Whether the motor wiring is reliable and whether the motor cable inlet hole has been sealed with rubber mud or oil mud to prevent water from entering the junction box.
- Whether the cable has been marked well according to the requirements and whether the lettering is clear.
- Whether the voltage and frequency are consistent with the indication marks on the motor and other electrical equipment.
What are the precautions in the operation process?
- The operation and maintenance of all equipment must be operated by dedicated personnel.
- Before starting the equipment, check whether all inlet and outlet pipeline valves are in the correct state.
- Before starting the equipment, check whether the slag catcher is clear and not blocked.
- Before starting the equipment, check whether the connection bolts are loose, or off.
- Before the centrifuge reaches the set speed, it is strictly prohibited to supply material to the centrifuge.
- Before the centrifuge shutdown, must stop feeding the centrifuge first.
- The centrifuge must be cleaned after the centrifuge feeding stop.
How to start the centrifuge?
- Turn on the main power supply Firstly, close the power main gate of the control cabinet and turn on the power.
- System login After the centrifuge control cabinet is powered on, wait for the system login page to pop up, as shown in Figure 1; click on the numeric input box, enter the user name and password, and click "Login". After logging in, click the "Read" button on the "Operating Instructions" screen, as shown in Figure 2. After clicking Read, it automatically enters the monitoring screen, as shown in Figure 3. Clicking on "Auto Start", the centrifuge starts automatically and waits for the speed and differential speed to reach the set value.
Start the feed pump
Start the feed pump and start the feed work.
How to shut down the centrifuge?
- Stop the feed pump and stop feeding. Click on the "Auto Stop" button, and the centrifuge will automatically delay the stop until it stops completely.
How to clean the centrifuge?
- Click on the "cleaning" button on the control interface, and enter the cleaning mode screen, as shown in Figure 5.
- Click on the "cleaning start", and the centrifuge automatically starts for cleaning mode.
- Open the cleaning water valve for cleaning.
- After cleaning, close the cleaning valve and the centrifuge will be stopped automatically.
Adjustment of feed volume
Adjust the size of the feed volume by adjusting the feed frequency of the feed pump and the size of the feed valve opening. When the machine is running, the submachine running torque should be controlled within 30%. When the current of the centrifuge motor and the torque of the submachine have a large rise, the feeding volume can be reduced appropriately or suspended.
Adjustment of drum speed
By setting the value of drum speed, the main motor running frequency is adjusted automatically. The greater the drum speed, the better the separation effect, but the higher the speed, the greater the load on the centrifuge and the more difficult it is to discharge slag. According to the change of material concentration, adjust the value of drum speed appropriately, when the centrifuge motor current and submachine torque have a large rise, the drum speed can be reduced appropriately.
Differential speed adjustment
By setting the set value of the differential speed, the sub-motor running frequency is automatically adjusted, the higher the differential speed, the faster the slag discharge speed; when the centrifuge motor current and the sub-motor torque rise, the differential speed can be increased appropriately (not more than 35).
Adjustment of slag discharging
During operation, when the slag output starts to become significantly wet, the differential speed can be reduced or the drum speed can be increased as appropriate.
Adjustment of water discharging
- In the course of operation, when the amount of slag in the water discharge begins to become significantly larger, you can appropriately increase the differential speed or increase the speed of the drum.
- In the course of operation, when the oil content of the water discharge begins to become significantly larger, you should check whether the material heating temperature is normal, as well as the emulsification of the material. If it is the change of material oil content, adjust the handle scale position.
- During operation, when the centrifuge does not dispense water for a long time, the motor current and torque keep rising, the vibration of the centrifuge becomes larger and there is an alarm, it is necessary to stop feeding the material and de-clog the centrifuge.
Adjustment of oil output
- In the operation process, when the water content of the oil output starts to become significantly larger, check whether the material heating temperature is normal, as well as the material emulsification. If the oil content of the material changes, adjust the handle scale position.
How to manually Unclog a centrifuge？
During the operation of the centrifuge, if the centrifuge does not discharge liquid or slag for a long time, and the auxiliary machine torque is too high, the bearing temperature and motor current value are too large so that there is an alarm shutdown, you must first stop feeding, shut down the centrifuge, and after the centrifuge is completely stopped, manually trigger the auxiliary motor coupling to observe whether it can be triggered. If it can be triggered, then clean the centrifuge in the same way as normal, or reverse the slag discharge by reversing the auxiliary machine and opening only the auxiliary machine. The specific operation steps are as follows.
- When the centrifuge motor is completely stopped, click on "Parameter Setting" in the monitoring screen and select the reverse of the auxiliary machine and drum.
- Click the "Manual" button in the control interface to enter the manual control interface. Set the speed of the auxiliary machine to 1000 rpm, click the button of "Auxiliary machine", when the button turns green, the auxiliary machine reversing is turned on, and the blocked material will be removed from the centrifuge.
- When the centrifuge slag is discharged and the motor current torque is normal, click the "Auxiliary Machine" button in manual mode. When the button turns gray, the auxiliary motor stops.
- when the auxiliary motor has come to a complete stop, enter the parameter setting mode and select the auxiliary motor and drum in the same direction option to restore the auxiliary motor direction.
- Cleaning the centrifuge in the right way.
Failure Analysis and Troubleshooting
The structure of the centrifuge is complex, the precision of the parts is very demanding, and the interplay is very strict, so the maintenance of the machine should be carried out by professionals, otherwise, it will be difficult to ensure the maintenance effect and safety. In order to help users to improve the ability to eliminate common faults, the analysis and treatment of some common faults are listed below for users' reference.
|Common Faults||Cause Analysis||Solution|
|Centrifuge won't power up||Machinery||1) Transmission part failure: a. Belt damage; b. Main bearing damage 2) Drum blocked: a.Drum deformation; b.Foreign body stuck; c.Bearing protection screws not loosened in transport to take away 3) The cover is not covered；the assembly insert is not inserted correctly 4) The drum has too much residue and the spiral is blocked.||For 1,2,3--Targeted troubleshooting; For 4--Add water to flush and manually operate the barring gear.|
|Centrifuge won't power up||Electrical||1)No power supply or supply voltage is too low 2)Main motor failure 3)Alarm and failure in the control cabinet 4)Connection line oxidation off, the main motor wiring is incorrect||Targeted troubleshooting|
|Excessive vibration||Process||1)Excessive material flow rate, unstable feed pressure 2)Excessive concentration fluctuations||1)For 1--Reduce the flow rate 2)For 2--Correct the process parameters|
|Excessive vibration||Machinery||1)Excessive vibration when starting, unable to reach the working speed, uneven deposits in the drum 2)Damage to the bearings on the drum or spiral 3)Loose connection of rotating parts 4)Uneven feeding 5)Bad dynamic balance of the new parts replaced 6)Severe wear of the spiral blades 7)Failure of the soft connection, shock absorbers 8)Unstable installation of the foundation, weak foundation, bracket||1)For 1--Not sufficiently cleaned before stopping. Should be filled with water to flush and manually operate the barring gear. 2)For 2--Replace damaged bearing 3)For 3--Check and repair 4)For 4--Adjust the load 5)For 5--Adjust or replace 6)For 6--Repair 7)For 7--Replace the shock absorber and soft connection 8)For 8--Further fix the machine's foot screws. Reasonable design and reinforced foundation|
|Abnormal noise||Process||1) The material flow rate is too large 2) There are many amorphous solids in the material||1) For 1--Reduced flow rate 2) For 2--Pre-removal of amorphous solids|
|Abnormal noise||Machinery||1)Dynamic balance damage (blockage, wear, deformation) 2)The host speed is too high 3)Excessive torque 4)Damage to the bearing on the drum or spiral 5)Lubricating oil temperature, oil quantity is abnormal, there is metal powder or foreign matter mixed in the oil 6)The discharge outlet is open 7)The slag outlet is not smooth||1)For 1--Overhaul relevant parts 2)For 2--Reduce the speed to the right amount 3)For 3--Reduce the torque to the right amount 4)For 4--Replace damaged bearings 5)For 5--Check and replace 6)For 6--Connect the discharge outlet with a pipe 7)For 7--Ensure the slag outlet is clear|
|Abnormal noise||Electrical||1)Main motor bearing or fan damage 2)Main motor rotor friction 3)The supply voltage is too high and the frequency is unstable||1)For 1--Replace the bearings or fan 2)For 2--Overhaul the rotor and stator of the main motor 3)For 3--Contact with power supply department|
|Excessive main bearing temperature (over 70℃)||Machinery||1)Bearing lack of oil 2)Too much grease 3)Bearing damage or clearance is too small 4)Bearing outer ring or inner ring displacement||1)For 1--Oiling the bearings as required 2)For 2--Failure can be eliminated automatically after running for a period of time 3)For 3--Replace the bearing or adjust the clearance 4)For 4--Repair the bores to the proper size|
|Excessive Gearbox temperature (over 75°C)||Process||Too much load||Adjusting the load|
|Excessive Gearbox temperature (over 75°C)||Machinery||1)Oil shortage of gearbox 2)Poor heat dissipation 3)Damage to internal bearings or parts of the gearbox 4)Incorrect type of lubricant or deterioration of lubricant 5)New gearbox 6)Excessive filling of lubricant in the gearbox||1)For 1--Check the oil level of the gearbox 2)For 2--Improve the ambient temperature 3)For 3--Overhaul the gearbox 4)For 4--Replace with a lubricant that meets the requirements or a new lubricant 5)For 5--Light load operation during the break-in period 6)For 6--Refill according to the manual|
|High fluctuation of differential speed||Machinery||1)Large amount of feed, large load 2)Large fluctuation of feed concentration||1)For 1--Adjust the feed amount 2)For 2--Correct the process parameters|
|High fluctuation of differential speed||Machinery||1)Spiral and drum rubbing 2)Damage of gearbox||1)For 1--Check the spiral 2)For 2--Replace|
|Stop during operation||Machinery||1)The bearing temperature is too high 2)Differential speed is too small 3)Overload of current or torque of sub motor 4)Excessive vibration 5)Damage or failure of relevant parts of the machine 6)Low inert gas pressure||1)For 1--Identify the cause and restore the protector 2)For 2--Adjust the differential speed 3)For 3--Reduce the feed load 4)For 5--Replace damaged parts 5)For 6--Increase the supply pressure of inert gas|
|Stop during operation||Electrical||1)Overload of the main motor 2)Control element failure 3)Display error 4)The improper setting value of technical parameters 5)Runaway sub-motor drive||1)For 1--Reduce the load 2)For 2--Check and replace 3)For 3--Repair the display and circuit 4)For 4--Reset the appropriate parameters 5)For 5--Overhaul the sub-motor drive|
|No slag discharge||Machinery||1)The concentration of suspension is too low or the feeding volume is too small 2)The density difference between the solid phase and liquid phase is too small 3)Machine rotation direction is opposite 4)Gearbox is damaged||1)For 1--Increase the feeding volume 2)For 2--Make improvements in the process 3)For 3--Identify the cause and correct it 4)For 4--Replace the gearbox with a new one|
|No slag discharge||Electrical||1)The automatic control system of feeding is out of order 2)Faulty sub motor system 3)Incorrect setting of machine parameters||1)For 1--Check the automatic control system 2)For 2--Check the sub motor system 3)For 3--Reset the parameters according to the actual situation|
|High water content in the discharged solids||Process||1)Differential speed is too large 2)Too much feeding volume 3)The feeding flow rate is too small 4)The material is difficult to be separated||1)For 1--Reduce the differential speed within the normal operation of the secondary motor 2)For 2--Reduce the amount of feed material 3)For 3--Increase the flow rate of material into the centrifuge 4)For 4--Improve the process|
|High water content in the discharged solids||Machinery||1)The liquid layer depth is too deep 2)The separation factor is not enough 3)The spiral propeller blade is worn 4)The operating frequency is not changed and the speed is reduced||1)For 1--Adjust the depth of the liquid layer 2)For 2--Increase the speed of the centrifuge 3)For 3--Repair the worn blade 4)For 4--Tighten the belt or replace the belt|
|High water content in the discharged solids||Electrical||1)The main motor speed drops 2)Sub-motor control is not functioning, and the differential speed is too large||1) For 1--Check the internal bearing and wiring of the main motor; check the voltage and frequency of the power supply 2) For 2--Adjust the differential speed to the right amount; check and troubleshoot the secondary motor control|
|High water content in the discharged liquid||Process||1)The solid content of the material entering the centrifuge increases 2)The flow rate into the centrifuge is increased 3)The nature of the material has changed 4)The material is difficult to separate||1)For 1--Reduce the amount of feed material 2)For 2--Reduce the flow rate into the centrifuge 3)For 3--Adjust the material handling process; readjust the machine settings 4)For 4--Improve the process|
|High water content in the discharged liquid||Machinery||1)The separation factor is not enough 2)The feeding volume is too large 3)The depth of the liquid layer is too shallow 4)The rotation speed of the main machine has dropped 5)The differential speed is too large||1)For 1--Increase the rotating speed of the drum 2)For 2--Reduce the feeding volume 3)For 3--Adjust the depth of the liquid layer 4)For 4--Check the belt tension and main motor 5)For 5--Adjust the differential speed to the appropriate value|
|High water content in the discharged liquid||Electrical||Sub-motor control failure/ Differential speed is too large||1. Adjust differential speed
2. Check and troubleshoot the sub-motor control
|High load, but no discharge||1)Drum discharge port blockage 2)Material accumulation between the shell and the drum 3)Blockage of material between feed pipe and spiral cone.||1)For 1--Stop the machine to check and exclude the blockage phenomenon 2)For 2--Open the hood to check 3)For 3--Pump out the feed tube and remove the residual material.|
|High current of the main motor of centrifuge, overheating||Machinery||1)Fault in the drum makes the main motor running current high 2)Main bearing failure 3)Frequent starting||1) For 1--Troubleshoot and reduce the load 2) For 2--Replace grease; Replace bearings|
|High current of the main motor of centrifuge, overheating||Electrical||1)Abnormal power supply 2)Main motor failure 3)The main motor wiring is wrong||1)For 1--Check the power supply 2)For 2--Overhaul the main motor 3)For 3--Correct the wiring; check the wiring firmly|