SU954743A1 - Method of drying loose materials - Google Patents

Description

(B) METHOD FOR DRYING BULK MATERIALS

one

The invention relates to a drying technique and can be used in the chemical, compound feed, construction and other industries of the industry, intended for drying wet bulk and adhering materials in a vibratory bed.

The known method of drying of dispersed materials in a fluidized bed by blowing a layer of coolant with simultaneous additional conductive heat ij

However, when using this method, the material may overheat.

It is also known for convective drying of bulk materials in the vibro-boiling layer created by the main heat carrier, and in the area of zag. loads to prevent sticking | particles create a flowing mode by supplying secondary coolant 2j,

This method requires an increased consumption of coolant in the zone

downloads to keep it flowing.

Also known is a method of drying fine materials in a vibrating layer during its movement from the loading zone to the unloading zone in contact with the coolant. The residence times of particles of material in a shank are governed by the formation of two opposite material flows upwards and

10 down T.

With this method, sticky granules form lumps in the stagnation zone.

15

There is also known a method of drying loose materials in a vibro-kip layer by applying to the material in the process of its zoning movement from the loading and heating zone to the area of loading circular and linear vibrations and blowing the layer in each zone with a flow of primary coolant, while the circular vibrations have 39 higher a frequency that is a multiple of the linear oscillation frequency J. However, the known method does not allow the linear velocity of the dried material to be smoothly and widely controlled during the drying process. At the same time, in the loading and heating zone, sticking of material to the walls of the drying chamber is inevitable. The purpose of the invention is to intensify heat and mass transfer and increase productivity. The goal is achieved by the fact that the secondary coolant is periodically introduced into the zone of the zaggakhs and heats in the form of a swirling flow creating a horizontal vortex, and in the remaining zones they create vertical vortices of the material being dried out using circular vibrations. FIG. 1 shows schematically a drying unit operating according to the inventive method, and a trajectory of movement of the dried material} in FIG. 2 - the same plan view. The installation contains a drying chamber with loading zone 1 and heating, drying 3 and 2 unloading zone, loading hopper 4, unloading bunker 5 source 6 of the primary heat carrier, source 7 of the secondary heat carrier, fan 8, cyclone 9. Bulk wet material from bunker k is continuously fed to zone 1 of loading and heating. Under the influence of vibration, as well as the supply of the primary coolant from source 6, the material moves from the loading and heating zone 1 to the drying zone 2 and further to the unloading zones 3 in the form of vertical vortices. To prevent particles of wet material from sticking to the walls of the chamber in zone 1, the secondary coolant from source 7, which forms a horizontal vortex, is periodically fed through each s in the form of a swirling flow for 0.5–3.0 minutes. The air jet knocks down particles of material adhering to the surface of the walls, and also prevents them from contacting with the wall. The exhaust coolant is sucked off by the fan 8 through the cyclone 9. In zone 1 (cylindrical), the material is heated and then fed successively to zones 2 and 3, which are made in the form of L-shaped vibrating troughs, perforated from the bottom. Under the influence of circular and linear oscillations, the material is continuously moved from the chute to the chute. Main circular oscillations, loosening the circular path. Linear vibrations created by a separate vibration exciter impose a translational component on the material. The speed of the directed linear oscillations makes it possible to control the residence time of the material in each groove. Depending on the mode of drying of a particular material and the required performance, calculate the required linear velocity. The linear vibration pulses of the drying chamber are transmitted to the particles of the material and move them with a slight lag from the natural vibration velocity. The linear velocity of the camera is 0.9-1.1 of the required linear velocity of the material being dried. . Tests show that when drying wet, strained to the adhesion of materials, for example, pellets of feed, concentrate feed lysine with filler, the particles in the loading zone on the walls do not stick, because the periodic supply of secondary coolant prevents particles from settling on them. For pellets of wet compressed feeds with a moisture content of 28-30, the optimal values for the time of supply of the secondary heat carrier are within 0.5-1.5 minutes. When the time is reduced to 0.3 minutes, a significant amount of adhering particles accumulates on the walls. The flow of heat carrier for more than 1.5 minutes (1.7 minutes) gives a result similar to the flow rate of heat-transfer agent during flow of 1.5 minutes. The optimal values of the velocity of linear oscillations are in the range of 15.3-18.7 mm / s at a particle speed of 17 mm / s. At a rate of linear oscillations of 15 mm / s, the particles of the material are overdried, the installation does not provide the design performance, at 19 mm / s, the oversized particles slip through and the installation performance is too high. When testing granules of fodder lysine concentrate with a filler that are prone to significant sticking to the walls and clumping, the speed of linear oscillations decreased, therefore, the speed of movement of particles also decreased. However, the pattern remains the same: the optimal values of the speed of linear oscillations are 0,, 1 of the speed of movement of the material. The supply time of the secondary coolant is increased and the time between feedings is reduced. The value of technological parameters, the duration of the supply of the secondary coolant, the intervals between feedings, the speed of the engine

Material experiments, as shown by experiments, depend on the physicochemical properties of bulk materials. Analysis of the experimental data shows that for most of the bulk materials under study, as well as materials prone to sticking together, the optimal values of the velocity of linear oscillations applied to the drying chamber are 0.9-1.1 material flow rates in it} and the duration of the supply of the secondary heat carrier in the loading and heating zone to create a swirling flow, it is 0.5-3.0 minutes with a range of seconds.

The proposed method intensifies the processes in the loading and heating zone, eliminates sticking of particles on the chamber walls; combines intensive loosening of material in drying zones

and increasing productivity, at the loading and heating zones. Periodically, the secondary coolant is introduced through the system in the form of a swirling flow, creating a horizontal vortex, and in the remaining zones, vertical vortices of the material being dried are created with circular oscillations.

Sources of information taken into account in the examination

1.Romankov P.G., Rashkovska N.B. Fluid bed drying. M.-L., Himi 196it, p. .

2. USSR author's certificate number 821877, cl. F 26 V 3/00, 1979.

3. USSR author's certificate №493601, cl. F 26-B 3/04, 1973.

Claims (1)

k. Copyright certificate CCCf. M ° 62307, cl. F 26 V 3/00, 1978. 36 for a given performance with the required residence time in certain zones. In general, the drying process is significantly intensified with increasing productivity, preserving product quality and saving heat. The invention of the method of drying loose materials in a vibrocarpment layer by imposing on the material in the process of its zoning movement from the loading and heating zone to the unloading zone of circular and linear vibrations and purging the layer in each zone with a flow of primary heat carrier, heat and mass transfer intensification