The countermeasure of drying sugary materials in small spray dryers is reasonable.

1, small spray dryer correctly select parameters, reasonable configuration of spray dryer sugary materials not necessarily all refers to (pure) sugar materials, but also includes sugary plants such as Chinese herbal medicine when the liquid, paper night contains sacchar acid, vegetables (such as tomato juice) and fruit juice, starch, cellulose hydrolytic products and other compounds.
for different sugar content, measured the glass change temperature, the development of dry operating conditions, the selection of design parameters is the fundamental method of zui.
first of all to make the process go through, non-stick walls, do not block, products can ensure quality.
the second requires the rationality of thermal energy and power consumption, reduces blind amplification, reduces excess power consumption, and convenient operation and other factors.
e.g. the export exhaust temperature of lactose drying should not be greater than 101 degrees C, small spray dryers should also try to take into account the possibility of the crystallization of lactose in the manufacturing process, so that it tends to stabilize the structure."
the design of the drying tower should be as short as possible to its constant speed period of time, so that the two phases of gas and liquid in the faster possible area mixing and contact, in order to improve the surface of the droplet heat transfer, mass transfer rate.
so that the particle surface appears dry in a short period of time, in the dry tower diameter design also combined with the liquid in the atomization of the spray distance, requiring the surface to dry before contact with the tower wall.
this is combined with the choice of atomization device, which includes the viscosity of the material, the solidification rate, the amount of spray, the atomization wheel speed (or pressure and aperture) correctly configured with sufficient heat sources and fan, etc.
2. Small spray dryer? Fine powder return from the cyclone separator part of the fine powder back to the atomization area can promote product reunion, particle growth, surface drying and so on.
In the return of fine powder should pay attention to is the need to use thick phase air flow transmission, if the use of thin phase transport, even if fine powder reached the atomization area, a large amount of air relative to very little dry powder so that droplets and dry powder can not collide and failure. the area returned by
fine powder can also be set in the inner wall of the dry tower, with fine powder air from the circular cut direction into the dry tower, so that the tower wall formed a thin gas film, air flow can be blown away adsorption of dry powder in the tower wall.
the air flow also to take into account the relative humidity of the air can not be too high, such as it is cooling dry powder after the hot air flow, because the gas heating relative humidity decreases without condensation.
the gas used in this method can be a thin phase transport 3. Spray dryer? Low temperature, low humidity drying conditions in order to avoid the glass state change temperature or thermal bioactive materials, requires the use of dehumidification and low temperature of the air spray drying, known abroad as the BIRS process, its air temperature is only 60 degrees C, the whole process is only a change in humidity and temperature changes little.
the process has a relatively low drying rate and therefore the drying tower appears to be very high to ensure the time it takes.
similar processes are used in tomato powder and dispersion dye production.
4. Small spray dryer? Local introduction of cold air at the end of the drying process, sprayed droplets have been dried, but often due to the exhaust temperature is greater than the glass transition temperature of the material caused by the condensation of material in the cyclone separator and blockage.
air is imported into the mixture with exhaust gas to reduce the gas temperature, can reduce the viscosity of the powder surface, but it is important to note that the inward air will increase the relative humidity of the mixture gas caused by the humidity of the powder surface to increase and reduce the Tg value.
safest way to do this is to freeze the dehumidifier before cold air enters the system.
is particularly necessary in the south of our country.
can be seen in spray drying of drugs or sugary materials.
5. Small spray dryer? Tower wall cleaning for low glass transition temperature powdery materials and some synthetic resin glue, after drying in a loose state attached to the inner wall of the dry tower, can be used to swing the riser pipe and the tower wall distance is very close, the tube into compressed air, in order to blow sweep the attachment of the tower wall.
this method can be used for sugary Chinese herbal drying is effective.
but for biologically active drugs, it is not recommended, because it is inevitable on the arm transfer device to accumulate materials, this part of the material once entered will affect product quality.
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