SU1595428A1 - Method of producing granulated tea - Google Patents

Abstract

The invention relates to the processing technology of small types of tea and can be used in the tea industry. The purpose of the invention is to improve the quality of the product and reduce energy consumption for the production of the finished product. The method of producing granulated tea from dry species includes the stages of grinding, moistening the raw material, molding it and two-stage drying in the heat carrier flow. The first stage of drying is carried out at a temperature of the heat carrier 110 ... 120 ° C and its speed of 1.4 ... 1.7 m / s for 4 ... 6 minutes, the second stage - at a temperature of the heat carrier 95 ... 100 ° C and its speed of 0.8 ... 1.1 m / s for 5 ... 8 min. At the end of the second stage of drying, the unconditioned fraction is separated by supplying a counter flow of nonconforming fraction to the fluidized bed at a temperature of the heat carrier 105 ... 110 ° C and its velocity 0.5-0.8 m / s. To further improve the quality of the finished product, the binder is prepared on the basis of tea extract, and the specified droplet diameter is maintained according to the ratio D M = (0.3 ... 0.55) D R, where D R is the equivalent particle diameter of the substandard fraction, mm

D M - median diameter of droplets, mm. With the same purpose, the counter-flow of air is supplied at a speed of 4.5 ... 6 m / s and a temperature of 25 ... 35 ° C. 2 hp f-ly.

Description

The invention relates to the processing technology of small types of tea and can be used in the tea industry enterprises.

The purpose of the invention is to improve the quality of the product and reduce energy consumption.

The method includes the stages of grinding and moistening the original syf, its molding, two-stage drying in the heat carrier stream. The first drying stage is carried out at a temperature of the heat carrier 110-120 ° C and its speed of 1.4 - 1.7 m / s for 4-6 minutes, the second

; the drying stage is carried out at a heat carrier temperature of 95-100 ° C and its speed of 0.8-1.1 m / s for 5-8 minutes; the substandard fraction is separated by; supplying a counter-flow of air, after which it is granulated by dispersing the binders in the I-fluidized bed of the unconditioned {fraction at the temperature of the coolant 105-1 and its speed 0.5-0.8 m / s. For the implementation of the method the binder can be prepared on the basis of tea extract; wearing

d (0.3-0.55) d

g

I where c1 is the equivalent particle diameter I of the nonconforming fraction, mm; I d - median droplet diameter, mm

At the same time, the counter-flow of air can be supplied at a speed of 4.5 - I 6.0 m / s and a temperature of 25-35 ° C. I Thus, a temperature of 110-120 ° C facilitates the rapid heating of the inner layers of granules at an air speed of 1.4. -1.7 m / s. The short duration of exposure to such a temperature together with an intense and uniform blown-up of the layer of granules does not cause overheating of the I (burnout) product, but increases; its quality. In addition, after the first: drying stage, most of the moisture is removed from the product, the extractives are concentrated on the surface of the constituent particles, thereby fixing the interparticle fluid bonds and transferring them to hardened bridge contact clots. At this temperature and air velocity, the concentration gradients and temperatures in the granules are equalized, moisture does not move in the form of sidness from the central layers to the periphery. Moisture from all layers is removed as vapor. In addition, with such a parity of moisture transfer gradients, there is no reason to fear granule rupture, i.e. the particle folding structure in the granule is almost unchanged. However, with the rapid removal of moisture from the plant-based wet material, some-.

second warping of particles. And if, prior to the proposed drying regime, the initial particles constituting the granule, appeared to be smooth lamellar

0

5 O 0 45 JQ.

five

after drying, they curve their surface after drying, which promotes the mechanical engagement between the particles and increases the strength of the granules.

Since the initial fine mass, from which the granules are formed by agglomeration, is crushed dry tea, when drying the molded wet mass, the liquid is removed through the interaggregate pores, without forming bubbles on the surface of the initial particles.

At the first stage of drying at a speed of 1.4-1.7 m / s and a heat carrier temperature of 110-120 ° C, the tea granulated mass warms up to 20-65 ° C. The specified short-term exposure to temperature combined with a high blowing rate of the granules with a heat carrier eliminates the conditions crust formation in: and the surface of the granules.

In the process of forming and drying, the product is mainly conditioned by the particle size distribution. In connection with a wide spectrum of the dispersed composition of the raw material, a small amount (7-12%) of a small non-commercial fraction is formed in the molding and drying processes. When it enters the target product, its quality and consumer properties are impaired (when brewing it gives a cloudy infusion). Therefore, after the second stage of drying, the dried product is separated into conditioning and fine fractions. For this, a counter note of air at a speed of 4.5–6 m / s and a temperature of 25–35 ° C is fed into the discharge opening. At the same time, the large granules fall off at the same time as their own weight, and the fine fractions enter the granulation stage. Granulation of fine fractions is carried out by dispersing the bonds to liquids in a fluidized bed at a temperature of 105-110 ° C and its velocity of 0.5-0.8 m / s.

Example: 400 g of dry tea moistened 400 g of liquid binder, mixed thoroughly, fed to an extruder with a 2 mm hole diameter. The molded mass is doused in a drum granulator and fed to the first section of the dryer with the following process parameters: heat carrier temperature, heat carrier velocity 1.5 m / s, drying time

5 5 min.

Then the product enters the second section, where it is dried at and the speed of the coolant 0.9 m / s for 7 minutes. Then, air is fed into the discharge opening at a speed of 5 m / s and a temperature of 30 ° C. A product with a granule size of 1 - 3 mm is unloaded. The fine fraction of 0.7-0.9 mm enters the third section of the dryer, where it is granulated with a dispersed solution of the binder component with a drop diameter of 0.25 mm.

The temperature of the coolant at the entrance to the granulation zone, and its velocity is 0.7 m / s.

The granulated tea product with a size of 1 to 3 mm, which does not disintegrate during brewing, is discharged from the dryer; the extract has an aroma characteristic of baikhov tea and taste, the product is quickly brewed, and retains its characteristic color. At all stages of drying: a uniform fluidization, the absence of stagnant zones is observed. Perezhenk granules no. The final moisture content of the product is 3.5%.

Claims (2)

1. Method of production of granulated tea from dry tea products 1595428 " with five about 0 production, including grinding the feedstock, wetting it, molding and unloading the finished product, two-stage drying in the heat carrier flow, characterized in that, in order to improve product quality and reduce energy consumption, the first drying stage is carried out at a heat carrier temperature of 110-120 ° C speed of 1.4-1.7 m / s for 4-6 min, the second stage of drying is carried out at a temperature of the heat carrier 95-100 ° C and its speed of 0.8-1.1 m / s for 5-8 min, and in the process of unloading the finished product, a sub-standard fraction is made by feeding the counter eye air, and the resulting fraction was subjected to further Substandard formovashpo by providing a pseudo-liquefied layer tep.1onositelem at 105-110 0 and velocity of 0.5-0.8 m / s while dispersing it in the binder solution 2. The method according to 1, distinguishing the yu, u, and u with the fact that the binding solution is prepared on the basis of tea extract, and during the dispersion process the diameter of the droplets is maintained at 0.3-0.55 equivalent diameter of the substandard fraction. The method according to claim 1, characterized in that the flow of a counter-flow of air is carried out at a speed of 4.5-6 m / s and a temperature of 25-35 ° C.