High-temperature melt pump is a gear pump, high-temperature melt pump is high temperature and high viscosity polymer melt delivery, pressurization and melt measurement is essential equipment. Compared with other types of pumps, the high-temperature melt pump has the advantages of compact structure, reliable operation, low energy consumption, high volumetric efficiency, small shear effect on the melt, stable flow at high viscosity and high pressure, and no outlet pressure fluctuation. The pump has its unique advantages and the key role in the process, making it play an irreplaceable role in polyester production. First, the structure and working principle of high temperature melt pump Melt gear pump from the pump housing, front and rear side cover, gear shaft, sliding bearings and shaft seal form. Melt gear pump is a positive displacement pump, work rely on the main and driven gears caused by changes in the work volume changes to transport the melt. Working volume by the pump body, gear tooth groove and the function of the side plate with the composition. When the gear rotates, the melt enters the tooth grooves of the two gears of the suction chamber. As the gear rotates, the melt is brought into the discharge cavity from both sides, and the gears mesh again to make the melt in the tooth grooves to be squeezed out Cavity, pressure delivery to the outlet pipe. As soon as the pump shaft is turned, the gear presses the melt down to the outlet side so that the pump outlet can reach very high pressure with little or no effect on flow and discharge pressure. High-viscosity gear pump gear are common spur, helical, herringbone, helical teeth, tooth profile are mainly involute and arc type. Usually small gear pump to use more involute spur gear, high temperature gear pump often use variable gear, conveying high viscosity, high pressure melt polymer melt more use of involute helical gears. Gear and shaft made of one, its rigidity and reliability is higher than gear and shaft separately manufactured gear pump. Foreign low-pressure gear pump gear is often used square structure, that gear tooth width equal to the addendum circle diameter. The high-pressure occasions used in high-viscosity gear pump gear tooth width less than its tip diameter, which is to reduce the gear radial compression area, reduce gear, bearing load. Second, the installation and use of high temperature melt pump 1. Carefully open the pump package carefully checked, if damaged or missing parts, please immediately contact with my company. The pump is made of high-temperature alloy steel, all parts are heat treated to a higher hardness, so the material is more brittle precision equipment. Any impact and impact may cause serious damage, it is recommended to install rings. 2. When installation, please accurately judge the pump inlet and outlet. When installed correctly, the pump shaft rotates clockwise. Install the motor, reducer, universal coupling and pump, the pump must be installed on the base fixed to ensure that the pump seat and the motor drive shaft concentricity, rotation must be free of stagnation, otherwise it will cause the gear housing, serious shaft fracture. 3. There are pressure sensor hole and temperature sensor hole in the pump body. Due to the correct installation of the sensor, the measurement data will be deviated. High strength (12.9) bolted connections at the pump body ensure safe pump operation. Just start the pump should be low speed operation. After the pump runs steadily, it can be gradually adjusted to the normal speed and pressure. If the pump is not stable, you must stop the pump to check the cause, so as to avoid serious pump internal damage. If the use of packing seal, often adjust the position of the seal cover, the seal is always in the best condition. Third, the high temperature melt pump removal and cleaning 1. Carefully remove the pump from the device, placed in a vacuum heating furnace slowly warming two hours to 400 ℃ -450 ℃. Temperature should not be overheating or easily lead to the decline of the hardness of the pump material, affecting the stability of the pump size. 2. In the process of warming, the residual material is dissolved and discharged. Unscrew the gland, front and rear cover bolts. All the components should be kept in mind and should be returned to their place of installation. Remove the gear due to residual solid material adhesion, do not use hard objects percussion and damage to the teeth and bearing corners, but should be gently tapped with plastic or soft copper to remove it. 3. Remove the gear pump and seal assembly should be placed on a clean countertop, clean the parts with compressed air or clean cotton cloth. And carefully check the components for wear, cracks, burrs and scratches. 600 # sandpaper can be used to gently polish the surface of the attachment, grinding be careful when measuring gear, plate and D-type bearings, must not go to its metal or ground it. Otherwise it will affect its measurement function. 4.After grinding, the parts should be washed with trichloroethane or vinyl chloride solvent and wipe again with a cotton cloth. Do not use paper towels because paper scraps or impurities may stick on the parts and can be installed after cleaning . Fourth, the assembly of high-temperature melt pump 1. Preparing a can of lubricating oil before assembly, the pump body, before and after the cover, the drive and driven gear, the seal assembly and gland assembly should be lubricated before assembly. When assembling strictly follow the disassembly order of each component, install them one by one so that the components are correctly positioned. 2. Before installing the bolt, please apply the thread part with the high-temperature grease and tighten the bolts of the front and the back cover diagonally. Always be able to freely rotate state. If there is any stuck phenomenon, do not assemble or rotate the pump strongly. If the assembly is correct, the parts should be easy to load and the pump shaft will rotate easily. Fifth, the common faults of high-temperature melt pump and countermeasures are as follows: (1) Symptom: the pump can not discharge; cause of the malfunction: a. Rotation direction is reversed; b. Suction or discharge valve is closed; c. Inlet without material or pressure is too low d. check the viscosity of the liquid, the speed of the flow rate at low speed when the operation is no (2) Symptom: Insufficient pump flow Problem Cause: a. Suction or discharge valve closed; b. Inlet pressure is low; c. Outlet line is blocked; d. Leakage of stuffing box; e. Check if the valve is open; c. Confirm the discharge is normal; d. Tighten; a large number of leaks affect production, should stop running, disassembly inspection; e. Check the pump The actual speed of the shaft; (3) the fault phenomenon: the sound abnormalities cause of the malfunction: a. Eccentric shaft coupling or poor lubrication b. Motor failure; c. Reducer abnormalities; d shaft seal installed poor; e shaft deformation or wear Countermeasures: a. Find or fill the grease; b. Check the motor; c. Check the bearings and gears; d. Check the shaft seal; e. Parking Disintegration inspection (4) Symptom: current is too large Fault causes: a. Outlet pressure is too high; b melt viscosity is too large; c shaft seal assembly bad; d shaft or bearing wear; e motor failure strategy: a Check the downstream equipment and pipelines; b. Viscosity test; c. Check the shaft seal, appropriate adjustments; d. Check after parking, hand crank car is too heavy; e. Check the motor (5) Symptom: Pump suddenly stop the cause of the malfunction : a power failure; b motor overload protection; c coupling damage; d outlet pressure is too high, interlocking reaction; e bite abnormal pump; f shaft and bearing adhesion stuck measures: a check Power; b. Check the motor; c. Open the safety cover, disc brake inspection; d. Check the instrument interlock system; e. After parking, reversing confirmation; c. A correspondence. ================================================== ================================================= Published by Asia Fluid Network Editor, please indicate Asia Fluid Network, to promote business consulting hotline:
Aluminium foil is produced by rolling sheet ingots cast from molten billet aluminium, then re-rolling on sheet and foil rolling mills to the desired thickness, or by continuously casting and cold rolling. To maintain a constant thickness in aluminium foil production, beta radiation is passed through the foil to a sensor on the other side. If the intensity becomes too high, then the rollers adjust, increasing the thickness. If the intensities become too low and the foil has become too thick, the rollers apply more pressure, causing the foil to be made thinner.
The continuous casting method is much less energy intensive and has become the preferred process.For thicknesses below 0.025 mm (1 mil), two layers are usually put together for the final pass and afterwards separated which produces foil with one bright side and one matte side. The two sides in contact with each other are matte and the exterior sides become bright; this is done to reduce tearing, increase production rates, control thickness, and get around the need for a smaller diameter roller.
Some lubrication is needed during the rolling stages; otherwise, the foil surface can become marked with a herringbone pattern. These lubricants are sprayed on the foil surface before passing through the mill rolls. Kerosene based lubricants are commonly used, although oils approved for food contact must be used for foil intended for food packaging.
Aluminium becomes work hardened during the cold rolling process and is annealed for most purposes. The rolls of foil are heated until the degree of softness is reached, which may be up to 340 °C (644 °F) for 12 hours. During this heating, the lubricating oils are burned off, leaving a dry surface. Lubricant oils may not be completely burnt off for hard temper rolls, which can make subsequent coating or printing more difficult.
The rolls of aluminium foil are then slit on slitter rewinding machines into smaller rolls. Roll slitting and rewinding is an essential part of the finishing process.
Aluminum Foil
Aluminum Foil,Aluminum Foil Tape,Soft Plain Aluminum Foil,Diamond Aluminum Foil
Luoyang Jinxuan Electronic Technology Co., Ltd. , http://www.jinxuanalu.com
