RU2369812C1 - Method of grain crop seed drying - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to the methods of grain crop drying and can be used in the agriculture at the enterprises engaged with seed grain laying-in. The grain crop seed drying method implies blowing of a fixed bed of the grain crop seeds under the load of 300 kg/m² during 10 minutes by the heat carrier 60-65°C hot and with the heat carrier speed at the seed bed entry equal to 0.4 m/s, the following aeration of the seed bed by the air 18-20°C hot during 10 minutes with the speed equal to 0.8 of the heat carrier speed at the seed bed entry. The cycle is repeated until the required humidity of the seeds is achieved.

EFFECT: beneficial result of the invention consists in the reduction of the seed material cost price.

2 cl, 4 dwg

Description

The invention relates to methods for drying seeds of grain crops and can be used in agriculture at enterprises engaged in the procurement of seed.

A known method of drying the cobs of seed corn in a fixed bed (A.S. USSR No. 380925, class F26B 3/06, 1970) by blowing it with a gaseous coolant. In order to intensify the process and increase efficiency, purging is carried out first with a coolant with a temperature of 52-62 ° C for 5-9 minutes, and then with a temperature of 30-36 ° C for 2-3 minutes, after which the cycle is repeated until ears of predetermined humidity.

A known method of drying the seed of various crops in a variable mode (A.E. Ivanov, N.M. Mitrofanov, F.N. Erk. Mechanization of seed production of perennial grasses, Leningrad "Kolos", 1981, pp. 96-97, prototype ), which consists in blowing a fixed layer of seed material with a heated coolant, followed by blowing it with unheated air, after which the cycle is repeated until the seed material reaches a predetermined humidity. With short-term exposure to the coolant, its maximum temperature can reach 60-65 ° C.

The variable drying mode allows you to economically consume thermal energy, eliminates overheating of seeds, helps to maintain their germination, increases the uniformity of drying under certain conditions. By improving the technology of drying seeds of cereal crops in a fixed bed by choosing the optimal drying parameters that take into account the critical temperature of crack formation and the permissible heating temperature of the material, an economic effect can be achieved that exceeds that known while maintaining the germination of seed material that satisfies agrotechnical requirements.

The problem solved by this invention is to increase the efficiency of the drying process of grain seeds while maintaining the germination of seed material.

The technical result obtained from the solution of the problem is to reduce the cost of seed.

The object of the invention is solved by the fact that in the method of drying seeds of cereal crops in a fixed bed by briefly blowing it with a coolant at a temperature of 60-65 ° C, followed by ventilation with unheated air, after which the cycle is repeated until the seeds reach a predetermined humidity, purging with a coolant of the seed layer at load of 300 kg / m ² and its unheated aeration air was carried out for 10 minutes each operation, whereby the rate of coolant at the inlet of the seed layer is 0.4 m / s and the velocity nepodo retogo air - from 0.8 coolant velocity. In addition, air with a temperature of 18-20 ° C is used to ventilate the layer of crops.

This drying mode is determined based on the results of studies using the method of multifactorial design of experiments. The following drying parameters were adopted:

1) the performance of evaporated moisture in the period of falling speed - q ^// ,

2) the time period of the incident drying speed - τ ″, h;

;3) specific heat energy consumption - E _t ,

;

;4) the specific cost of electricity - E _e ,

;

;5) the total specific energy consumption - E,

;

as well as factors that determine the drying process:

- коэффициент пульсации по нагреву и охлаждению семян зерновых культур, где τ₀ - время охлаждения, мин, τ_H - время нагрева, мин;

- ripple coefficient for heating and cooling seeds of grain crops, where τ ₀ - cooling time, min, τ _H - heating time, min;

- время нагрева, мин;

- heating time, min;

- коэффициент «пульсации» по скорости теплоносителя,

- coefficient of "ripple" in the speed of the coolant,

where ν ₀ is the velocity of ventilated air, m / s, ν _H is the velocity of the coolant;

- скорость теплоносителя при нагреве, м/с.

- coolant speed during heating, m / s.

For each parameter, depending on the selected factors, mathematical models of the drying process are obtained in the form of regression equations, based on which dependency graphs are constructed:

evaporated moisture performance from the “ripple” coefficient for heating and cooling (1), heating time (2), the “ripple” coefficient for speed (3), the heating rate (4) shown in FIG. 3, as well as the total costs energy from the coefficients of the "ripple" in speed (3), speed during heating (4), shown in figure 4.

A generalized analysis of the obtained graphs of the dependence of the adopted parameters on these factors shows the following. The drying time of seeds of grain crops, in particular wheat grain, in the alternating mode to the greatest extent depends on the first factor - the coefficient of "ripple" in terms of heating and cooling times. Moreover, the lower the level of this factor, i.e. the shorter the cooling time and the longer the heating time, the shorter the drying process to conditional grain moisture, respectively, the greater the productivity of the drying device (figure 3). But in the aggregate of all factors, for the adoption of an acceptable level within the accepted limits, the action of such a minimum acting factor is necessary, the most favorable level of which would combine the levels of other factors. Analyzing the graphs of energy consumption (figure 4), we observe that the optimal result for heat costs gives the second factor with a lower level (-2). In terms of energy costs, the second factor at the zero level is again uniting. And by the total energy consumption, the heating time factor makes it possible to determine the levels for other factors. Thus, guided by the graphs of the total energy consumption, it is possible to determine the optimal levels of factors and their values, namely, the “ripple” coefficient for heating and cooling is (+0.36), the heating time is (-1), the “ripple” coefficient is for speed heat carrier - (-1), heat carrier velocity during heating - (- 2). This means that with a heating time of the layer 5.5 minutes, the cooling time should be 1.16 times longer and equal to 6.4 minutes, and at a coolant speed of 0.4 m / s, the speed of unheated air should be 0.8 times smaller and equal to 0.32 m / s. With the constructive development of devices that create variable operating modes of dryers, it is obviously easier to organize the same time with a coolant and with unheated air. Then the “ripple” coefficients will take values equal to unity, and the values of the noted factors will be close to their accepted zero level, i.e. equal to 10 minutes. In this case, the cost-effectiveness in terms of energy consumption, as can be seen from the graphs in Fig. 4, deteriorates slightly.

The image is illustrated by drawings.

Figure 1 shows the drying complex with an air distributor, a schematic diagram, figure 2 is the same, section aa in figure 1; figure 3 shows graphs of the performance of evaporated moisture from the coefficient of "ripple" for heating and cooling (1), heating time (2), the coefficient of "ripple" in speed (3), speed during heating (4); figure 4 - graphs of the dependence of the total energy consumption from the coefficients of the "ripple" for heating and cooling (1), heating time (2), the coefficient of "ripple" in speed (3), speed during heating (4).

The method of drying grain seeds includes the following operations:

- blowing a fixed layer of seeds of grain crops at a load of 300 kg / m ² for 10 minutes with a coolant with a temperature of 60-65 ° C and a coolant velocity at the entrance to the seed layer of 0.4 m / s;

- subsequent ventilation of the grain seed layer with air with a temperature of 18-20 ° C for 10 minutes at a speed equal to 0.8 of the velocity of the coolant at the entrance to the seed layer;

- then the cycle is repeated until the seeds of the crops reach the specified moisture content.

The method of drying seeds of grain crops is as follows.

The claimed method of drying seeds of grain crops was implemented at the post-harvest grain processing center at the Sakharov educational and experimental farm of the Tver State Agricultural Academy.

The drying complex includes two layer dryers with drying chambers 1 and 2, a heat generator 3 and two centrifugal fans 4, 5. To create a variable drying mode, a collector-air distributor 6 with a rotary valve 7 is used, with each extreme position of which a specific drying mode of the material is set. The rotary valve 7 is driven by an actuator 8, which is controlled by an automatic remote control 9.

Example 1. Wheat grain was dried. In the drying chambers 1, 2 of the dryer with wheat grain at a load of the seed layer of 300 kg / m ² , the coolant was alternately supplied - hot air with a temperature of 60-65 ° C, by blowing it with the grain layer for 10 minutes at a speed at the entrance to the seed layer 0.4 m / s and air with a temperature of 18-20 ° C by ventilating the seed layer for 10 minutes at a speed of 0.32 m / s. Moreover, if the grain layer is purged in the drying chamber 1 with a heat trap, then in the chamber 2 the grain is ventilated, and vice versa. The desired moisture content of wheat grain was reached after 2.5 hours.

Electricity costs were determined by measuring the drying time, the magnitude of the current and voltage in the electric motor network and multiplying their value. Specific energy consumption amounted to

Example 2. Drying was subjected to oat grain similarly to drying of wheat grain.

The desired moisture content of oat grain was reached after 2.6 hours. Specific energy costs amounted to

Control experiments show that with a variable drying mode with a coolant temperature of 60-65 ° С and a cooling air temperature of 18-20 ° С in a cycle of 10 minutes and, respectively, with an air flow rate of 0.4 m / s and 0.32 m / s , a reduction of thermal energy costs of 32% is achieved, and the total energy consumption is reduced by 17% compared to the conventional drying mode without cooling the seed layer and at a constant coolant velocity of 0.4 m / s.

By reducing the cost of thermal energy for drying the seeds of grain crops, a 17% reduction in their cost as a sowing material is achieved.

Claims (2)

1. The method of drying seeds of grain crops in a fixed layer by briefly blowing it with a coolant with a temperature of 60-65 ° C, followed by ventilation with unheated air, after which the cycle is repeated until the seeds reach a predetermined humidity, characterized in that the coolant is purged with a seed layer at a load of 300 kg / m and its ventilation with unheated air is carried out for 10 minutes each operation, while the velocity of the coolant at the entrance to the seed layer is 0.4 m / s, and the velocity of unheated air is 0.8 of the speed t plonositelya. 2. The method according to claim 1, characterized in that air with a temperature of 18-20 ° C is used to ventilate the seed layer of grain crops.

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