SU1211550A2 - Method of drying dispersed materials - Google Patents

Description

one

The invention relates to a drying technique, and more specifically to a method of drying in an oscillating mode, and can be used in the microbiological industry for supsi amino acids: L-leucine, L-isoleucine L-threonine, L-trintofan and others, as well as for deep drying of thermally unstable, dusting, sintering; 1xC and lumping dispersed materials in the medical, pharmaceutical and pharmaceutical, food and chemical industries. The invention is an improvement of the known method, according to the authors. No. 954742.

 The aim of the invention is to intensify heat and mass transfer and improve the quality of drying by preventing the particles from agglomerating.

The method is carried out with, using the installation shown in the drawing.

The installation contains a drying chamber 1, gas distribution grid 2 with the material being dried 3, filter 4, profile knives 5, Heating of the product, release of pressure. Neither, vacuuming or throwing of the U-duct is carried out with the help of high-speed valves 6-9, vacuum receiver 10 and vacuum system (not shown). The volume of the receiver 10 is equal to or several times greater than the volume of the drying chamber 1. Valve 6 is required to connect the drying chamber 1 with the coolant supply line or with the atmosphere. By means of the valve 7, the drying chamber 1 either communicates with the atmosphere, connects to a vacuum system, or completely closes. Through the valve 8, the drying chamber 1 is connected to the receiver 10, and the valve 9 connects the receiver 10 to the vacuum system.

The installation works as follows.

Heating of the dried material 3 is carried out convectively in a densely blown or fluidized bed mode. Through the valve 6, the coolant is supplied, which, after the roaring of the wetting material 3, is released through the filter 4 and the valve 7 to the atmosphere. At the same time, the valve 8 is closed, and the valve 9 is connected to the vacuum system, which operates on the receiver 10, lowering the pressure in it. After expiry of 550502

At the heating time, valves 5, 7, and 9 overlap, and valve 8 connects the drying chamber 1 to the BaKy TvinoMy counter 10. In the drying chamber 1

5, the pressure is released for a period of not more than 0.5 s, during which in the first period the pressure in the pores of the agglomerates formed in the heating stage of material 3 becomes higher than the pressure of the environment and a pressure gradient occurs within the wedge-shaped moist material 3 which causes intense filtering / flux, diffusion, and thermal diffusion fluid flows and a vapor – gas mixture from the sinter of the agglomerate to its surface. When dvcalkepi of these flows, internal stresses arise in the agglomerates, which lead to their loosening and destruction.

At the vacuuming stage, the valve 8 overlaps, and the valve 7 connects the exhaust chamber 1 to the suction vacuum system. There is a subsequent increase in the depth of BaKyy-: via to the desired value, during which moisture evaporates.

0 due to the internal heat stored in the material 3 (adiabatic drying) and cooling of the material 3. Subsequent evacuation allows to reduce heat loss and to obtain

5 material 3 with a low residual Grade. At the end of the vacuum pump stage, the valve 7 seals the drying chamber I, and the rarefied underlayer space, the quick-acting valve 6, communicates with the atmosphere. A pre-loosened material 3 is agitated, which, in a collision with pozhami 5, is additionally ground, then

valve 7 connects the suction chamber 1 with a.t1 Yosphere, and valve 6 connects to the heat agent supply line and the cycle repeats until the first critical humidity is reached

50

material. In the second period of drying, vacuuming is carried out in the same way as described in the main invention.

Example, Laboratory tests of the proposed method .55 were carried out on a vacuum suction unit with a drying unit with a drying chamber diameter of 105 mm, a height of 250 mm and a ratio of the receiver volume to the dryer volume

Noah camera, equals three. Dried pure amino acid L-threonine for medical purposes (Belsh crystalline, highly dispersed product). Experiments were performed under the following conditions: initial moisture content of Ug is 0.35 kg of moisture / kg of dry product; moisture removal - binary liquid mixture ethanol - water; the initial composition of the mixture is 50% by volume of ethanol, 50% by volume of water, the final moisture content of the product according to the technological regulations U i 0.01 kg of moisture / kg of dry product, the amount of loading

0.25 kg, the height of the layer is the drying time was

downloadable product

35 mm; beginning0

to the temperature of the heat agent t 80 С, the final temperature of the heat agent changed during the process depending on the temperature and moisture content

product within t 30-60 ° С, consumption of heat agent G 4,16x10

g

m / s

the initial moisture content of the heat agent Ujj is 0.0176 kg of moisture / kg of dry air, the final moisture content of the heat agent varied along the way. ProRedactor I.Rybchenko

Compiled by N.Isachenko

Tehred M. Parotsay Proofreader A. T sko

Order 631/44 Circulation 635 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod, Project 4 street

depending on the moisture content of the product within U 0.03-0.0475 kg of moisture / kg of dry air,

R

residual pressure in receiver P

 10-kPa, residual pressure in ka-j

as dryers P, 25 kPa, time for pressure relief in the drycaps

- 0.5 s.

As a result of drying L-threonine according to the proposed method, a homogeneous structure product was obtained without agglomerates of particles, the maximum size of lumps did not exceed 0.65 + 0.05 mm.

37 min, final moisture content of 0.005 kg of moisture / kg of dry product. The quality of drying was determined by the final moisture content and dispersion

20 composition of amino acids, respectively, thermogravimetric method and sieve analysis.

In this method, other amino acids were also dried.

25 microbiological synthesis, L-leucine, L-isoleucine, L-tryptophan.

Claims (1)

METHOD OF DRYING DISPERSED MATERIALS by ed. No. 954742, characterized in that, in order to intensify heat and mass transfer and improve the quality of drying by preventing particle agglomeration, prior to the first evacuation, a pressure is released to 1-10 - 5 ”10 Pa for a duration of no more than 0.5 s, followed by a decrease in pressure to a predetermined degree of evacuation. FROM* SU „1211550