Affect the boiling dryer effect of factors
Plastic particles drying is a relatively simple process, However, in some cases, the particle is not completely dry. The factors affecting the drying effect of the fluid bed dryer:
● drying temperature: the heat is to open the water molecules and the key forces between the hygroscopic polymer. When above a certain temperature, the attraction between water molecules and polymer chain will greatly reduce the water vapor by dry air away.
● Dew Point: In the fluid bed dryer, first remove the moist air, contain very low residual moisture (dew point). Then, by heating the air to reduce its relative humidity. At this time, the dry air of low vapor pressure. By heating the particles within the water molecules from the binding force bound to the proliferation of the surrounding air of particles.
● Hours: in the air around particles, absorption of heat and water molecules to the particle surface diffusion will take some time. Resin suppliers should therefore, detailed description of the type of material in the effective drying time must be spent under the appropriate temperature and dew point.
● Airflow: hot, dry air, heat transfer to particles in the drying hopper to remove the moisture of the grain surface, and then the moisture back to the fluid bed dryer. Therefore, there must be sufficient airflow to the resin is heated to drying temperature, and temperature to maintain a certain time
Long-term use and development of the fluid bed dryer in the structure, performance has significantly improved, the quality is improving, but there are still some problems, the following production practice recommendations for improvement:
A boiling dryer is in form an air convection drying equipment, compared with the conduction drying equipment, energy consumption is indeed large, but if you take some measures you can achieve a good energy saving effect. Suggestions:
1 to strengthen the sealing effect of the equipment. Most of the fluid bed dryer hopper with the device body with a flange connection, poor sealing effect, the proposed design the switch to the convex surface of flange connections; import pump Custer red wine
Two dryers are used in the steel wound finned heat exchanger, pipe material cost savings, but the effect of heat transfer is not good, it is recommended to switch to brass;
To increase the insulation measures. The heat exchanger shell to add insulation layer to minimize heat loss.
To trap the dust removal device of the improvements suggested
Second, the smooth flow of process operation on condition that the material has good fluidization state, high-efficiency filter dust collector to the continuation of this state. Filter Precipitator efficiency largely determines the boiling effect. The dust shaking bag dust and pulse cleaning dust two kinds.
Shaking bag dust
By the reciprocating motion of the cylinder trap bag shake vibration to achieve the effect of dust cloth bag with anti-static, non-fiber shedding cloth production, trapping bags with integral lifting the form. The problem is the dismantling of the bag filter inconvenient, is not reasonable selection of hanging bars, easy to cause deformation, resulting in Mifengbuyan can also cause changes in the run powder and air volume, not only pollute the environment, but also reduces the product yield. Suggestions: filter bags with clamp connections to connect, hanging bars to choose is not easy deformation of rigid material, and regularly check to replace the cloth bag.
Pulse cleaning dust
With the domestic solenoid valve technology to further improve and further reduce the price of the pulse cleaning dust gradually become the mainstream of the traps. Filter used two kinds of cloth bags and stainless steel sintered wire mesh. Among them, the sintered stainless steel mesh filter is the only guarantee any material yield can reach more than 99% of the products. Problem cleaning technology has been basically solved, the advantages of stainless steel sintered mesh filter in the yield and lifetime is gradually revealed more and more pharmaceutical companies use. |
Fluid bed dryer production effects cause analysis and improvement measures