The drying of flash dryer is the most commonly used unit operation. The production of bulk drugs and preparations has been widely applied. From the heat transfer method, convection, conduction, radiation and so on. The existing drying equipment is convection heat transfer drying, hot air drying, hot air drying contact, heat transfer and evaporation. Typical parallel flow dryer equipment, ventilation dryer, rotary dryer, dryer, fluidized bed dryer, spray dryer application, those, plus, prototype variants, and so on. Air drying, fluidized bed drying and spray dryer are hot air as heat source, such as drying, but also complete the processing of materials, the main feature is not to drive part of the convection drying process of energy saving drier exhaust dust and stench, when large air volume should end well.
The flash dryer is driven by a rotating stirrer with a strong wind field. The impeller rotates at a high speed under a strong function. The material is affected and rubbed. Under the action of shearing force, the block material is quickly crushed. It is in good contact with the hot air. The material is heated, dried and effectively prevented from sticking to the wall and deteriorating heat. Sensitive materials, and powder products that can be dried evenly, eliminate the classification and screening process of breakage.
The material of flash dryer has strong shearing, blowing and rotating action, the selection of various charging devices, continuous and stable feeding, and will not produce bridge phenomenon. In the process of introducing advanced technology, the concept is reasonable in design, compact in structure, wide in scope of application, large production capacity, good product quality, high efficiency, energy saving, drying, crushing and grinding in the equipment. The performance of screening disposable, eliminating environmental pollution and flash dryer has reached the international advanced technology level.
Common troubleshooting methods
First, poor feed.
1. As the cake-like material is easy to cause bridge erection above the screw conveyor shaft, resulting in empty rotation of the conveyor shaft, it is required that the cake entering the hopper must be less than 10 cm in diameter. When the material causes bridge erection, the bridge should be broken in operation to ensure smooth input.
2. Check whether the screw blades are mixed with metal sheets or coarse and long fibers and other impurities. If abnormalities are found, the screw conveyor should be reversed to remove the impurities.
3. Check whether the raw material solidifies in the screw conveyor, causing the conveying blade to be unable to push, and find similar situation should be cleared in time.
4. If the motor or parts do not rotate, check whether the power cord head falls off, whether the coupling connecting screw falls off, and solve the problem in time.
Two, crushing system:
1. Dead bed: when the timing motor is started, the grinding system does not work or when the equipment runs, it suddenly stops working. There are two reasons:
First, the raw material deposition, the whole crushing blade locked, can not operate, in this case should be immediately off the power supply to remove the sediment.
Secondly, excessive feeding, water evaporation not in time to accumulate too much, hindering the normal operation, at this time should be properly cleared accumulated after reducing the amount of feeding, to ensure the normal operation of the system.
2. Noise:
When hearing the noise of the comminution (stirring) system when it is working, it shows that there is already a hard foreign body entering, light will cause the deformation of the comminution tool, heavy will cause the breakage of the comminution tool and spindle. Therefore, when hearing the abnormal noise, it should immediately slow down the speed of the motor to close, check the damage degree of the comminution tool, and remove the impurities. In general, as long as after the removal of debris will be eight-shaped cutter shaping, broken blade welding, can be restarted, spindle fracture need to find the manufacturer for overhaul.
Three. Receiving system:
1. Imperfect discharge: due to the strong adhesion of light and fine materials, the cone may not flow smoothly when discharging in whirlwind. At this time, the cone must be tapped lightly so that the material attached to the pipe wall will fall after vibration. In order to ensure that the cone does not deform when tapped, a reinforcing ring or vibration can be added to the cone. Iron bar.
2. Material Running: Under normal circumstances, most dry products should be unloaded in the collecting cyclone separator, such as too much material accumulated in the secondary cyclone or pulse bag filter, that is, there are problems in sealing or operation of the collecting cyclone separator. The solid content of the waste gas after collecting dust by pulse bag filter should be controlled at 2%. Under the condition that there are too many solids in the exhaust gas, it is necessary to check whether there is a deflation phenomenon in the dust collector.
Cause: a. When the cyclone separator unloads, the two suction plates open the air leak at the same time, which will instantly reverse the flow of the cyclone and the crushed material in the pipeline, and increase the working pressure of the two cyclone and pulse bag filter, which can be removed according to the operation rules.
B. The fineness of powder is less than the number of filter bags. When the fineness of material is less than 200 mesh, the dust removal effect of ordinary pearl-like filter bags will be affected. And after one year of normal use, it is best to replace the filter bag regularly to achieve the best results. If the material is too thin, it is better to use membrane filter bags.
C. The filter bag is damaged or slipped. When the problem is found, the filter bag should be replaced in time, and the bag should be tightened so that the equipment can be used normally to achieve the best results.
D. The sealing property between the ceiling and Venturi tube is poor (the screw is loose or the rubber washer is aged), so the screw should be fixed and the washer should be replaced.
E and high air outlet temperature (above 150 C) cause the filter bag to harden and deform and affect the filter bag effect. The equipment temperature control should be adjusted in time.
F, it is recommended to add water bath dust removal to ensure dust collection and environmental protection effect.
Four. Host dust and powder spray:
When the flash drying unit is in normal operation, the tube is operated under negative pressure, that is, the air pressure and air volume of the induced draft fan should be greater than that of the blower, and when the main engine appears dust.
