RU2503901C1 - Seed and grain drying method and device - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: drying method of seeds and grain, as per which they are loaded, gravitationally moved through drying and cooling zones, a drying agent is supplied to a drying zone, cyclically dried, unloaded or cooled. A new feature of the method is that some amount of drying agent is chosen from the drying zone and reversed to the cooling zone. Seed and grain drying device includes loading 1 and unloading bunkers 12, drying 2 and cooling 3 chambers, fans 6, 9, furnace 10, loading and unloading means, partition wall 13 between drying 2 and cooling 3 chambers. A new feature of the device is that cooling chambers 3 include casing 4 with valve 14 and reversible fan 5, partition wall - valve 15 with possibility of reversing the drying agent from drying chambers to cooling 3 chambers.

EFFECT: improving productivity at cyclic operation, at drying of the first grain batch.

2 cl, 1 dwg

Description

The invention relates to drying of seeds and grain, mainly of high humidity and can be used in agriculture and the procurement system.

A known method of drying seeds and grains, in which the wet material is loaded, ventilated with a drying agent, cooled and unloaded. There is also known a device for drying seeds and grain of periodic action, containing a drying chamber, a fan and a heat generator (Guidelines for the selection and effective use of grain-drying equipment, G.S. Okun, A.G. Chizhikov, E.L. Revyakin, Federal State Institution Rosinformagrotech, 2006, p. 87-89). These method and device are widely used in agriculture for drying seeds and grain, mainly of high humidity. However, it is costly and little productive.

A known method of drying seeds and grain is that the grain is loaded, gravitationally moved from top to bottom through the drying and cooling zones, in the drying zone it is vented with a drying agent, in the cooling zone with outside air, it is cyclically dried, cooled and unloaded. (V.F. Samochetov, G.A. Dzhogoryan, Grain drying., M. "Kolos", from 177-178).

A device for drying seeds and grains is known, including loading and unloading bins, drying and cooling chambers, fans of the drying and cooling chambers, a furnace, means of loading and unloading.

(Guidelines for the selection and efficient use of grain drying equipment, G.S. Okun, A.G. Chizhikov, E.L. Revyakin, Federal State Institution "Rosinformagroteh", 2006, p. 40).

These method and device are close in their technical essence to the declared one and are taken as a prototype.

According to this method, the first batch of grain is dried before the dryer is transferred to the stream, and seeds and grain of high humidity (more than 21%), which are not suitable for drying in the stream, are cyclically dried. This method involves a reduced temperature of the drying agent, the operation of the fan of the cooling zone and is characterized by low intensity, and the device does not allow to intensify the process.

An object of the invention is to increase the productivity of the device during cyclic operation, as well as when drying the first batch of grain.

The stated technical problem is achieved by the fact that in the method of drying seeds and grain, which consists in the fact that the seeds and grain are loaded, gravitationally moved from top to bottom through the drying and cooling zones, the drying agent is fed into the drying zone, the seeds and grain are cyclically dried, cooled and unloaded According to the invention, a part of the drying agent is taken from the drying zone and reversed to a cooling one.

The task is also achieved by the fact that in a device containing loading and unloading bins, drying and cooling chambers, fans, a furnace, loading and unloading means, a separation wall between the drying and cooling chambers, according to the invention, the cooling chambers are equipped with a casing with valves and a reversing fan and the dividing wall - with valves with the possibility of reversing the drying agent from drying to cooling chambers.

The method can only be implemented in the proposed device.

The invention is illustrated in the drawing.

Figure 1 presents a diagram of a device for drying seeds and grains.

A device for drying seeds and grain contains a loading hopper 1, drying chambers 2, cooling chambers 3, a casing 4 of cooling chambers 3, a reversible fan 5 cooling chambers 3, feeders 6, a discharge means 7, a collector 8, a fan 9 of the drying chambers 2, a furnace 10 , elevator 11, discharge hopper 12, separation wall between chambers 13, air valves 14 and 15, level sensors 16, grain valve 17. The scheme includes wet grain 18, dry grain 19, circulating grain 20.

The device operates as follows.

Valve 17 is circulated. With wet grain 18, the first flow of the elevator 11 is sequentially filled with cooling 3, drying 2 chambers and loading hopper 1 until the level 16 sensors are triggered, after which the elevator 11 is automatically turned off. Feeders 6 and unloading means 7 do not include, the valve 14 on the casing is closed, and the valves 15 on the partition wall 13 are open. Then turn on the fan 9 and fan 5 for suction, kindle the furnace 10 and heat the seeds and grain in the device at 10 ... 15 ° C, then again turn on the noria 11, unloading means 7, feeders 6 and carry out cyclic drying of the material with the reverse part of the drying agent through valves 15 into the cooling chamber. The dried and cooled grain is unloaded, and then wet grain is fed into the device and the cycle is repeated. In the case of continuous drying, when the grain reaches a conditional humidity, the valves 15 are closed, the valve 14 is opened, and the fan 5 is switched to discharge. The valve 17 is placed in the "flow" position. The dried and cooled grain from the cooling chamber 3 through the feeders 6, the unloading means 7, the elevator 11 is removed from the dryer.

The method is carried out as follows: the material is loaded, cyclically transferred through drying and cooling chambers, vented with a drying agent, part of the drying agent is taken from the drying zone and sent to the cooling zone, the dried seeds and grain are unloaded with cooling or transferring the dryer to a stream.

Before starting the grain dryer on the stream, it is necessary to dry the first batch of grain, which is dried at a reduced temperature of the drying agent and the supply of external air to the cooling chambers. During circulation (the dryer works “on its own”), the grain consumption is comparable with the capacity of the elevator, which increases the porosity of the layer and the drying efficiency. In fact, we have an oscillating drying mode, in any case, the drying efficiency of the first batch of grain, as well as cyclic drying, is less high than when the outdoor air fan is off due to partial cooling of the material.

In the case of reverse part of the drying agent through the cooling chambers 3 we have a reverse drying. It is difficult to give a comparative characteristic of the drying efficiency of these modes at the same thermal load of the furnace. However, in the case of reverse, the heat transfer surface in the dryer increases due to cooling chambers 3, the latter leading to a decrease in the speed of the drying agent in the layer and to a decrease in this component of the pressure loss. Therefore, an increased consumption of the drying agent is possible and, accordingly, a greater amount of heat can be transferred to the grain, given that in this mode (cyclic or when drying the first batch), the furnace does not work at full capacity.

Example 1. We assume that the heat transfer surface of the dryer due to the cooling chambers 3 increases by one third during the implementation of reverse drying.

In this case, the velocity in the grain layer decreases from the standard 0.4 m / s to ~ 0.31 m / s. For a fan of type Ts4-76, No. 12.5 or its analogue (dryer SZT-16) with a nominal capacity of 60 thousand m ³ / h, this decrease in the speed of the drying agent reduces the pressure loss in the grain layer from 1.2 kPa to 0.8 kPa, and the total resistance from 1.8 to 1.4 kPa with an increase in flow rate to 76 thousand m ³ / h (Guidelines for drying and cooling grain by active ventilation, compiled by V.I. Aniskin, V.M. Lurie, V .A. Rybaruk, M., VIM, 1974, p.20, 42). An increase in the consumption of the drying agent leads to an increase in productivity both during drying of the first batch and during cyclic operation. The increase in the productivity of the dryer, depending on the moisture content of the grain at the stage of cyclic operation and drying of the first batch of grain, will be 0.6 ... 0.8 from an increase in consumption, i.e. by 18 ... 21%.

We show the possibility of efficient drying during continuous operation of the dryer.

Example 2. Drying of wheat seeds with a moisture content of 20 ... 21% in NWT - 16 is carried out at a maximum temperature of a drying agent of not more than 55 ° C, to a temperature of heating seeds and grain of not more than 45 °, and the permissible temperature for cooling seeds and grain is not higher than +10 ° C in relation to the outside air temperature.

Under these conditions, when 1/3 of their heat-exchange surface is alienated from the cooling chambers with respect to the outside temperature, for example, 20 ° C, the weighted average temperature of the cooling agent will be ~ 31 ° C, which will ensure the cooling process.

When drying grain, the maximum temperature of the drying agent rises to 80 ... 90 ° C and the decrease in the heat transfer surface of the cooling chambers will be at least 0.2 ... 0.25% with normative cooling.

Claims (2)

1. The method of drying seeds and grain, which consists in the fact that the seeds and grain are loaded, gravitationally moved through the drying and cooling zones, the drying agent is fed into the drying zone, the seeds and grain are cyclically dried, cooled and unloaded, characterized in that a part of the drying agent taken from the drying zone and reversed to the cooling zone. 2. A device for drying seeds and grain containing loading and unloading bins, drying and cooling chambers, fans, a furnace, loading and unloading means, a separation wall between the drying and cooling chambers, characterized in that the cooling chambers are equipped with a casing with valves and a reversible fan and the dividing wall - with valves with the possibility of reversing the drying agent from drying to cooling chambers.