RU2420940C1 - Power-saving method to disinfect lupine seeds against anthracnose - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: method consists in the fact that lupine seeds are disinfected by means of their heating. Seeds are heated to the specified temperature with convective heat supply in a coolant heated up to the necessary temperature. The coolant with the relative humidity of 30-40% is blown through a layer of seeds with thickness that does not exceed 0.15-0.20 m. Seeds in the coolant flow are soaked at the achieved temperature for 1.5-2.0 hours. The coolant temperature is maintained at the level defined according to the following ratio: T_opt = (123.9…125.0) - 0.021W₀ ³ + 0.806W₀ ² - 11.28W₀ , where W₀ - initial moisture of seeds, % ; T_opt - optimal temperature of coolant with its relative humidity within the limits of 30-40%, °C.

EFFECT: invention makes it possible to reduce power inputs by 35-40%, to increase technological process reliability with provision of practically full disinfection of seeds against anthracnose provided that sowing properties of seeds are preserved.

5 tbl

Description

The invention relates to agriculture and may find application in crop production for the disinfection of lupine seeds from the pathogen anthracnose.

A known method of thermal disinfection of lupine seeds from the pathogen anthracnose [5], including heating the seeds to a predetermined temperature with convective heat supply in a stream of a coolant with a moisture content of 79 ... 84%, blown through a seed layer with a thickness not exceeding 0.10 ... 0.15 m, followed by keeping them at the reached temperature for a certain period of time, determined by the ratio:

τ _opt. = 0.016 (T _at -50) · 10 ^{(341 + 1.74W} ₀ ^{) / (38 + 0.62W} ₀ ^{) -0.1T} _at , h

where T _in - the temperature of the coolant, ° C;

W ₀ - initial seed moisture,%.

(Patent No. 2249935. - Bull. No. 11. - 04/20/2005) [6] (analog).

However, the energy consumption for heat treatment of seeds remains significant and amounts to about 180 kW · h / t [2, 4].

In addition, according to this method, the blown seed layer is held at a given temperature for a certain time, determined by the above ratio. However, if this time is insignificant, then due to the very low thermal conductivity of lupine seeds, it is not possible to obtain a high quality of disinfection. So, for example, if the heat treatment time, determined by the ratio, turns out to be at the level of 0.5 ... 1.0 hour, then the spores of anthracnose located on the cotyledons (inside the grains) can survive, since only the duration of heating the seeds to a given temperature from due to their low thermal conductivity is usually 0.3 ... 0.35 hours. At the same time, the quality of disinfection decreases, and the reliability of the process also decreases.

The method of thermal disinfection of lupine seeds from the anthracnose pathogen known to the claimed technical essence is closest, including heating the seeds to the required temperature with convective heat supply in a heat carrier flow with a moisture content of 79-84%, blown through a seed layer 0.10-0 thick, 15 m, followed by keeping the seeds in the specified stream at the achieved temperature for 1.5-2.0 hours. Moreover, the temperature of the coolant is determined by the ratios:

- for seeds of yellow fodder lupine

- for white lupine seeds

Moreover, T _min ≤T _extra ≤T _max ,

where W ₀ - the initial moisture content of the seeds received for processing,%;

,

и

,

- минимальная и предельная температура при термообработке желтого и белого видов люпина, °С.

,

and

,

- the minimum and maximum temperature during heat treatment of yellow and white types of lupine, ° C.

(Patent No. 2286663, Bull. No. 31, 10.11.2006) [6] (prototype).

For the practical implementation of this method, an installation with a productivity of 180 ... 200 kg / h was developed and manufactured [2, 3, 4].

However, the specific energy consumption for the heat treatment of lupine seeds using this method remains very high. According to the test results of the method in 2008, with a thickness of the blown layer of 0.15 m, they amounted to about 164 kWh / t (table 4).

Due to a significant increase in electricity tariffs in 2008, thermal disinfection of lupine seeds in the near future may turn out to be expensive and inaccessible for wide practical use.

There is the problem of creating a new technical solution, an effective method of heat treatment of lupine seeds, which allows to significantly reduce energy consumption and increase the reliability of the process while ensuring almost complete disinfection of lupine seeds from anthracnose while maintaining their sowing qualities.

Reducing the energy consumption for thermal disinfection of lupine seeds can be done by reducing the exposure to heat, as noted above. However, according to the known processing method [6] (prototype), the duration of seed disinfection of 1.5-2.0 hours is not possible to reduce, since the prototype contains the optimal time for heating the seeds, the reduction of which leads to disruption of the technological process and, as a result, to a decrease quality of disinfection.

One of the real ways to significantly reduce energy costs for thermal disinfection of lupine seeds is to reduce the relative humidity of the coolant, which uses a steam-air mixture. According to the prototype [6], the coolant heated to 60 ... 75 ° C is humidified to 79-84% by supplying water vapor to the installation chamber and maintaining it at that level throughout the entire period of thermal exposure - 1.5-2.0 hours.

With this humidity of the heat carrier, the drying out of the seeds is excluded, and their moisture is kept almost at the initial level during the entire heat treatment.

However, it is necessary to spend more than 100 kWh of electricity for each ton of seeds to maintain such a high coolant humidity in the installation chamber during the entire period of heat exposure, amounting to 1.5-2.0 hours (Table 4). In this regard, even a slight decrease in the humidity of the coolant will significantly reduce energy consumption.

The results of experimental studies on the influence of the relative humidity of the coolant on the sowing quality of seeds and the level of infection with their anthracnosis during thermal disinfection are presented in tables 1, 2 and 3.

It was established (see table 1) that at a coolant temperature of 72.4 ° C, corresponding to the maximum allowable value, determined by the formula (see prototype):

In the process of heat treatment of seeds of yellow and narrow-leaved species of lupine with an initial moisture content of 8.4%, with a decrease in the relative humidity of the coolant from 79-84% to 30-40%, the sowing quality of the seeds is maintained at the initial level. At the same time, the content of anthracnose decreases to 0.4%. In individual seed samples, their almost complete disinfection is ensured.

Thus, when the coolant humidity decreases from 79 ... 84% to 30 ... 40% and its temperature is at the level of the maximum permissible value determined by the relation (1), anthracnose, although at the minimum level (0.4%), remains that is, when the coolant humidity decreases from 79 ... 84% to 30 ... 40%, a certain decrease in the process reliability is noted.

Moreover, with a further decrease in coolant humidity - to 18-20 and, finally, to 4-6%, the percentage of seeds affected by anthracnose remains at a higher level: 1.6 and 2.8%, respectively, although their sowing qualities remain at the original level.

Table 1 The influence of heat carrier humidity on the sowing qualities of seeds of yellow and narrow-leaved species of lupine, artificially infected with anthracnose to the level of 43.6% during their thermal disinfection (experiment 1) Heat carrier temperature, ° С Humidity,% The moisture content of the seeds,% The defeat of anthracnose,% Length, mm: hypocotyl root Germination,% before processing after processing the control - 8.4 - 43.6 54.5 / 75.6 89.2 72,4 79-84 8.4 8.4 - 49.1 / 84.0 90.0 72,4 30-40 8.4 8.0 0.4 46.5 / 69.6 89.6 72,4 18-20 8.4 7.4 1,6 45.9 / 73.7 84.0 72,4 4-6 8.4 7.5 2,8 43.0 / 71.1 91.6

table 2 The influence of heat carrier humidity on the sowing quality of seeds of yellow and narrow-leaved species of lupine, artificially infected with anthracnose to the level of 31.2% during their thermal disinfection (experiment 2) Heat carrier temperature, ° С Humidity,% The moisture content of the seeds,% The defeat of anthracnose,% Length, mm: hypocotyl root Germination,% before processing after processing the control - 9.7 - 31,2 42.2 / 77.1 91.6 72,4 79-84 9.3 8.6 - 35.6 / 71.9 89.0 72,4 30-40 9.3 8.3 - 38.2 / 78.1 94.4 72,4 18-20 9,4 7.3 0.8 38.6 / 64.1 92.0 72,4 4-6 9.5 7.0 1,2 35.6 / 68.6 93.6

Table 3 The influence of the relative humidity of the coolant on the sowing quality of the seeds of yellow and narrow-leaved species of lupine, artificially infected with anthracnose to the level of 37.6% during their thermal disinfection (experiment 3) Heat carrier temperature, ° С Humidity,% The moisture content of the seeds,% The defeat of anthracnose,% Length, mm: hypocotyl root Germination,% before processing after processing the control - 10.0 10.0 37.6 37.8 / 70.2 98.8 70.0 (prototype) 79-84 9.7 9.7 0 36.6 / 71.9 98.4 72.5 30-40 9.7 9.3 0 37.2 / 70.8 98.1 72.5 18-20 9.5 7.6 0.8 35.4 / 69.3 99.6 72.5 4-6 9.7 7.3 2,8 34.2 / 73.1 98.8 74.0 4-6 10.0 7.3 5.2 42.3 / 78.5 99.6

This is explained by the fact that at a relative humidity of the coolant of 30-40%, the seeds heated within 2 hours dry slightly, from 8.4% to 8.0%, that is, only 0.4%, which did not have a significant effect to the mode of their heat treatment. At the same time, at a coolant moisture content of 18-20%, the seeds dry in the same 2 hours to a moisture content of 7.5-7.7%, that is, 0.9-1.0%.

A decrease in seed moisture to such a level leads to a disruption of the technological process at which a temperature of 72.4 ° C was insufficient to ensure the complete death of anthracnose spores, although the sowing quality of the seeds is maintained at almost the initial level.

According to the known method, when the seed moisture content is 7.4-7.5%, to ensure complete disinfection of the seeds of yellow and narrow-leaved species of lupine, the temperature of the coolant must be maintained at 74.25-74.50 ° C [2, 4].

In order to increase the reliability of the process and ensure high quality disinfection of seeds of yellow and narrow-leaved species of lupine, artificially infected with anthracnose to the level of 31.2%, the maximum allowable temperature, determined by the ratio (1), was increased by 1 ... 4 ° C.

So, in experiment 2, with a seed moisture content of 9.3-9.5%, a thermal exposure time of 2.0 hours and a coolant temperature of 72.4 ° C, which is 1.4 ° C higher than the maximum allowable value determined by the ratio (1 ), or with the help of tables [2, 4], almost complete disinfection of seeds from anthracnose is ensured both at a coolant humidity of 79-84%, and when it is reduced to a level of 30-40%. Sowing qualities of seeds at a coolant moisture content of 30-40% are maintained at the initial level. In this case, modes with a coolant temperature of 1.4 ° C higher than the maximum allowable value determined by the relation (1) are more preferable, since, with all other conditions being equal, the process reliability is increased.

At a relative coolant humidity of 18–20% and 4–6%, as in experiment 1, the content of anthracnose in heated seeds remained at the level of 0.8–1.2%. This can be explained by a significant decrease in seed moisture during heat exposure from 9.3% to 7.0-7.3%, by 2.0-2.3%. With such a combination of characteristics: initial seed moisture of 9.3-9.5%, steam-air mixture humidity in the range of 18-20 and its temperature of 72.4 ° C, it is not possible to achieve almost complete disinfection of seeds from anthracnose, although the sowing quality of the seeds is preserved at the initial level.

In another experiment, up to 37.6% artificially infected with anthracnose seeds of narrow-leafed lupine species with a moisture content of 9.7% were subjected to heat exposure for 2 hours at a temperature of 2.5 ° C higher than the maximum allowed, determined by the relation (1), or according to the tables [2, 4], at different coolant humidity: 30-40%, 18-20% and 4-6%.

From table 3 it follows that, with the totality of the above characteristics, a decrease in the heat carrier moisture from 79-84 to 30-40% did not affect the quality of seed heat treatment: almost complete disinfection of seeds from anthracnose is ensured, provided that their sowing qualities are preserved (Table 3).

However, even at a coolant temperature of 2.5-4.0 ° C higher than the maximum allowable and a decrease in the humidity of the steam-air mixture from 79-84% to 18-20 and then to 4-6%, respectively, it is not possible to achieve complete seed disinfection. The content of anthracnose during the heat treatment is reduced from 37.8% to 2.8-5.2%. At the same time, when disinfecting lupine seeds according to the known method (prototype) (Table 3) with an initial seed moisture of 9.7%, exposure time for 2.0 hours, humidity of a steam-air mixture of 79-84%, at its temperature of 70 ° C , which corresponds to the maximum allowable value, determined by the relation (1), or using tables [2, 4], almost complete disinfection of seeds from anthracnose is ensured with preservation of their sowing qualities.

In all cases, regardless of the humidity of the steam-air mixture, the sowing quality of the seeds is maintained at the initial level of 98.8-99.6%. At the control level, the length of the hypocotyl and root were also preserved (Table 3).

Table 4 shows the results of studies on the impact on the amount of energy consumed by the humidity of the coolant blown through the bed in the range from 4-6 to 79-84%.

It was found that with a decrease in the humidity of the air-vapor mixture in the installation chamber from 79-84% to 4-6%, the cost of electricity for the heat treatment of lupine seeds decreases from 23.04 kWh to 7.45 kWh, i.e. more than 3 times.

Table 4 Influence of heat carrier moisture on energy consumption during thermal disinfection of lupine seeds Indicators unit of measurement Humidity,% 75-80 30-40 18-20 4-6 one 2 3 four 5 6 Energy consumed by the installation kWh 23.04 13.84 9.04 7.45 Specific energy costs, with the thickness of the blown layer of seeds: A) 0.010 m

245.8 147.6 96.4 79.5 B) 0.15 m

163.9 98.4 64.3 53.0 C) 0.20 m

122.9 73.8 48,2 39.7

The specific energy consumption per ton of heated seeds, while depending on the thickness of the blown layer, is reduced from 122.9-163.8 to 39.7-53.0 kWh / t.

As a result of the studies, the possibility of a significant reduction in energy consumption for the thermal disinfection of lupine seeds by reducing the relative humidity of the steam-air mixture (coolant) was established.

At the same time, an increase in the temperature of the coolant by 1.4-2.5 ° C in relation to the maximum allowable gives more stable results in the quality of seed disinfection, regardless of the degree of infection with their anthracnose. This increases the reliability of the process.

Thus, in order to reduce energy consumption, improve the reliability of the anthracnose disinfection process for seeds of yellow and narrow-leaved lupine species, it is advisable to heat them at a relative humidity of the steam-air mixture (coolant) in the range of 30-40%, and its temperature must be maintained by 1.4 -2.5 ° C above the maximum allowable, determined by the ratio (1).

Ultimately, the ratio for determining the temperature of the vapor-air mixture in the present invention will take the form:

where T _opt is the optimum temperature of the coolant with a humidity of the steam-air mixture of 30-40%.

The purpose of the invention is to reduce energy consumption, increase the reliability of the process.

This goal is achieved by the fact that in the method of thermal disinfection of lupine seeds from the pathogen anthracnose, which includes heating the seeds to the required temperature with convective heat supply in a stream of a heat carrier heated to the required temperature, blown through a seed layer 0.15-0.20 m thick, followed by keeping in the flow of the coolant at the achieved temperature for 1.5-2.0 hours, according to the invention, the seeds are subjected to heat at a relative humidity of the coolant in the range of 30-40%, and its rate the structure is maintained at a level determined by the ratio:

where W ₀ - the initial moisture content of the seeds,%,

T _opt - the optimum temperature of the coolant, with a humidity of the steam-air mixture of 30-40%, ° C.

The method is carried out on a known installation, including a sealed chamber consisting of 3 sections, a fan, a heater, a steam generator, a discharge and suction air ducts, a circulation circuit, a grain loader in the installation [2, 3, 4].

The upper section of the chamber is the working section, the middle section is unloading, and, finally, the lower discharge section.

A tipping platform is mounted on the shaft in the upper section. The working surface of the platform is covered with a mesh cloth on which grain is loaded with a layer of 0.15-0.20 m. To rotate the platform when unloading grain from the chamber, a reversible electric drive is provided, which allows you to return it to its original position after unloading the treated seeds.

The middle section contains a perforated pitched board installed at an angle of 45 degrees. An unloading window is provided at the bottom of the middle section.

In the upper section above the platform there is a leveling device that can move above the platform from one edge of the camera to the opposite along the guides.

In the lower section of the sealed chamber there is a window connecting the chamber with the discharge pipe of the fan. The upper section is equipped with the same window connecting the installation chamber with the air circuit of the circulation circuit to the suction pipe of the fan.

The air heater is installed on the suction section of the circulation circuit, directly at the suction window of the fan, and is designed to heat the coolant to a predetermined temperature.

The steam generator is designed to supply water vapor through the steam line to the intake air pipe of the circulation circuit.

The inventive method of disinfecting lupine seeds from the anthracnose pathogen satisfies the condition of patentability - "inventive step", since the purpose of the invention is to reduce energy consumption and improve the reliability of the process, while maintaining the sowing qualities of the seeds, can be achieved only with a combination of characteristics: the lupine seeds in the coolant stream are subjected heat exposure when the humidity of the steam-air mixture is in the range of 30-40%, and the temperature of the coolant is maintained at a level elyaemom by relation (2).

An example of a specific implementation of the proposed method of heat treatment of lupine seeds at a coolant moisture content of 30-40% in comparison with the known one, where its moisture during the heating of seeds is maintained at 79-84%, with natural infection of yellow and narrow-leaved seeds of lupine species 0, -4.4 % are shown in table 5.

From the table it follows that the inventive method allows for almost complete disinfection of seeds from anthracnose in a layer up to 0.2 m thick at a coolant moisture content in the range of 30-40% and the actual temperature, determined by the ratio (2). In this case, the sowing qualities of the seeds remain almost at the initial level, as evidenced by the data on the germination table, as well as the length of the hypocotyl and root (columns 7 and 8).

Thus, the claimed method of heat treatment from anthracnose seeds of yellow and narrow-leaved species of lupine can reduce energy costs by 35-40%, increase the reliability of the process, while ensuring their almost complete disinfection from anthracnose, while maintaining the sowing qualities.

Information sources

1. Derkachev I.P. "The thermal method of disinfecting lupine seeds from anthracnose." // Feed production, No. 6, 2005, - p.24-25.

2. Derkachev I.P. "Installation for thermal disinfection of lupine seeds from anthracnose" // Sat. scientific works - Bryansk 2007, pp. 232-244.

3. Derkachev I.P. “To presowing thermal disinfection of lupine seeds from anthracnose” // Sat. scientific works of the XV International Scientific and Practical Conference, October 12, 15, 2007 - Moscow, VIM, 2008. - pp. 239-247.

4. Derkachev I.P. “Guidelines for the effective use of the plant for disinfection of lupine seeds from anthracnose” - Bryansk, 2006.

5. Derkachev I.P., Takunov I.P. “Method for thermal disinfection of lupine seeds from the pathogen anthracnose” // Patent No. 2249935. - Bull. No. 11. - 04/20/2005 (analogue).

6. Derkachev I.P., Takunov I.P. "The method of thermal disinfection of lupine seeds from the causative agent of anthracnose" // Patent for invention No. 2286663 - Bull. No. 31 - November 10, 2006 (prototype).

Claims (1)

A method of thermal disinfection of lupine seeds from anthracnose, which includes heating the seeds to the required temperature with convective heat supply in a stream of a heat carrier heated to the required temperature, blown through a seed layer with a thickness not exceeding 0.15-0.20 m, followed by keeping it in a heat carrier flow at the achieved temperature for 1.5-2.0 hours, characterized in that the seeds are subjected to heat at a relative humidity of the coolant in the range of 30-40%, and its temperature is maintained at a level determined ratio
T _opt = (123.9 ... 125.0) -0.021W ₀ ³ + 0.806W ₀ ² ,
where W ₀ is the initial seed moisture,%;
T _opt - the optimum temperature of the coolant with its relative humidity in the range of 30-40%, ° C.