RU2615289C1 - Oscillating grain drying technique - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: oscillating method of drying grain is when the grain is loaded, gravitationally moved, periodically purged with the high-temperature drying agent, cooled and discharged. What is new is the fact that low-temperature drying agent is continuously supplied, the temperature of the grain at the end of the heating period and at the end of the cooling period is determined by the calculation formula. As a low-temperature drying agent, low-calorie combustion products are used.

EFFECT: reduced costs.

1 dwg

Description

The invention relates to the drying of seeds and grain and can be used in agriculture.

A known method of drying seeds of grain, in which the wet material is loaded, gravitationally moved, ventilated with a drying agent, cooled and unloaded (Anatasevich V.I. Grain drying. - M .: V.O. Agropromizdat, 1989. - P. 17-19) .

A device for this drying method is also known, containing a furnace, mines, a cooling column, a silo hopper, fans, elevators (Anatasevich V.I. Grain drying. - M .: V.O. Agropromizdat, 1989. - P. 48-49) . These method and device are widely used in agriculture for drying seeds and grain.

The main disadvantage of this method is due to the rapid heating of the material with low moisture removal, which is caused by the specific properties of grain as a colloidal capillary-porous body. Accordingly, it is necessary to limit the temperature of the drying agent, arrange for curing, etc. A device operating by this method is characterized by low efficiency.

There is a drying method, in which the grain in the falling layer of the dryer in four zones is periodically blown with a high and low temperature drying agent or atmospheric air, dried and cooled.

There is also known a device for implementing the known method, comprising two shafts with four heating and cooling zones, a distribution chamber, an exhaust device, a drying hopper (Sharshunov V.A., Rukshan L.V. Drying and storage of grain. - Minsk: Misanta, 2010. - S. 315-316).

The known method is closest in its technical essence to the claimed and adopted as a prototype. It provides drying of seeds and grain, but has reserves to reduce the cost of the process.

An object of the invention is to increase the drying efficiency, in particular the partial use of low-calorie fuel.

The problem is achieved in that in the method of oscillating drying of the grain, which consists in the fact that the grain is loaded, gravitationally moved, periodically purged with a high-temperature drying agent, cooled and unloaded, according to the invention, the low-temperature drying agent is fed continuously, the grain temperature at the end of the heating period is limited:

θ ' _pd = θ _pd + Δθ, ° C,

and at the end of the cooling period:

θ _ox = θ _pd -Δθ, ° C,

where θ _pd - the maximum allowable temperature for heating seeds, ° C;

;

;

τ _n , τ _oh - periods of heating and cooling of the grain, min,

in addition, low-calorie fuel combustion products are used as a low-temperature drying agent.

The oscillating grain drying device includes a solid fuel hopper 1, a dispenser 2, a primary blast fan 3, a secondary blast fan 4, a liquid burner 5, a combustion unit 6, an air heater 7, an air heater fan 8, a smoke exhauster 9, a manifold 10, a diffuser 11, a dryer 12.

The operation of the dryer is as follows.

The solid material from the hopper 1 is fed into the dispenser 2 and blown by the primary blower fan 3 into the furnace unit 6, where it is weighed when the secondary blast is fed by the fan 4. Liquid fuel is fed through the liquid burner 5 and it is ignited.

The combustion products enter the air heater 7 and are sucked off by the exhaust fan 9. With the fan 8, external air is supplied to the air heater 7, then through the collector 10 and the diffuser 11 to the dryer 12, in which the grain is dried.

The method is as follows.

Solid and periodically liquid fuels are constantly supplied to the furnace unit.

Grain heating is carried out to a temperature θ _'nq followed by cooling to a temperature θ _ox.

A sinusoidal change in the temperature of the grain with an amplitude of ± Δθ will maintain θ _pd ≈const, which will provide an effective and safe drying mode. Burning low-calorie solid fuels: chopped straw, husks of sunflower, rice, buckwheat, fine wood waste, the cost of which is significantly lower than liquid fuel, will significantly reduce the cost of the process.

The maximum permissible temperature for heating grain with constant heat supply can be written as (Ptitsyn S.D. Zernosushilki. - M .: Mashgiz, 1962. - 52 p.):

where W is the moisture content of the grain,%;

τ is the heating time, min

With an oscillating drying mode θ ' _pd during the exposure to a high-temperature drying agent, one can write:

;Where

;

τ _n, τ _oh - the duration of the heating and cooling periods, min.

When calculating (1) from (2) and simplification we get:

Accordingly, we have:

and

The temperature of the low-calorie combustion products changes its flow and partly by changing the secondary blowing in the range 1.1-1.3 _m = α (where α - excess blast), high reactive fuel combustion products are driven by changing the temperature of the liquid fuel flow at α = _w 1 05-1.1. The values of excess α _t and α _W provide economical operation of the furnace block and heat generator, which provides low-cost drying.

Indeed, in farms where sunflower seeds are cultivated, husk not only has no price, but certain costs are required for its utilization. Since the calorific value of husk is one fourth of liquid fuel, the economy will be at least ~ 25%, and a slightly lower saving will be ~ 15% when burning straw.

The direct supply of combustion products to the diffuser dryer is undesirable due to the possible unevenness of grain drying, which is regulated (± 1.5%).

Example. The TBR-2.0 combustion unit for burning plant waste in a unit with a SZT-30 dryer was tested at the Borisoglebsk creamery. As solid fuel, sunflower husk was burned with continuous supply of fuel. Liquid fuel was periodically fed into the reaction chamber, in which the husk was burned. Thus, in the SZT-30 dryer, in which the drying of sunflower seeds was carried out, an oscillating regime was organized. Seeds were dried from 12-15% to 7% humidity, the dryer capacity was 12 t / h at a temperature of heated air of 80 ° C.

The consumption of liquid fuel for drying was reduced by ~ 50% compared with the operation of the dryer only on liquid fuel.

Claims (8)

The method of oscillating drying of grain, which consists in the fact that the grain is loaded, gravitationally moved, periodically purged with a high-temperature drying agent, cooled and unloaded, characterized in that the low-temperature drying agent is fed continuously, the grain temperature at the end of the heating period is limited:

, and at the end of the cooling period:

, where θ _pd - the maximum allowable temperature for heating seeds, ° C;

, τ _n , τ _oh - periods of heating and cooling of the grain, min, in addition, low-calorie fuel combustion products are used as a low-temperature drying agent.

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