CN104061773A - Circulating dryer for cereals - Google Patents

Abstract

The invention discloses a grain circulation dryer, which comprises a radiation drying section, a grain discharge section, a hot air drying section and a grain storage section arranged on a base in sequence from bottom to top, and a material is arranged between the radiation drying section and the grain storage section. The circulation conveying device is connected with a heat source capable of generating heat medium on one side of the radiation drying section, and is respectively provided with an induced draft fan and an air mixing chamber on both sides of the hot air drying section, and the inlet of the air mixing chamber communicates with the heat medium outlet of the radiation drying section , the outlet of the air mixing chamber communicates with the induced draft fan through the hot air drying section. The advantages of the present invention are: not only hot air drying can be realized alone, but also hot air drying and radiation drying can be organically combined, so that the energy of high-temperature heat medium can be fully utilized in both high-grade and low-grade, high thermal efficiency, low energy consumption, and sufficient drying Uniformity, low drying cost, uniform temperature, good safety.

Description

A grain circulation dryer

technical field

The invention relates to the technical field of grain drying, in particular to a novel grain circulation dryer.

Background technique

Drying is one of the most important processing stages in grain production. The so-called drying is the process of removing moisture from the material by means of heat supply, which is a complex heat and mass transfer process. In order to ensure the good quality of grain in drying operation, appropriate drying conditions and equipment must be selected to minimize the adverse effects of drying on grain quality.

At present, atmospheric pressure hot air drying using hot air as the medium for convective heat transfer is still the most widely used and most economical grain dehydration storage method, such as cross-flow grain dryers. The grain channel of the cross-flow grain dryer is a vertical grain channel made of two layers of vertical nets. The grain forms a layer of grain wall in the channel, and the grain moves from top to bottom in the channel; the heating device is a coal-fired hot air stove . When drying, let the hot air blow through the grain wall to realize the heating and drying of the grain. This kind of grain drying equipment and its process have long drying time, low drying efficiency and thermal efficiency of the whole machine, high temperature of drying medium, high energy consumption, difficult drying, poor quality of dried grain, and heat-sensitive nutrients or active ingredients such as vitamins. The loss is serious, the crack rate is large, and the structural deformation is severe.

Far-infrared drying technology is a new type of drying technology. It is a high-efficiency heating technology that provides high energy, high strength, full band, high density and strong penetration. It is widely used in painting, printing and dyeing, electronics, medicine, textile leather, wood, paper, plastic, furniture, metal, automobile, grain drying and other fields. Such as Shanghai Sanjiu circulation far infrared dryer and the far infrared dryer produced by Jinzi Agricultural Machinery (Wuxi) Co., Ltd. However, due to improper cooperation between the infrared radiator of the far-infrared dryer and the hot air drying device, there are shortcomings such as uneven drying, high temperature, and easy fire, etc., and new inventions are urgently needed to solve the above problems.

Chinese patent CN203586723U is a new type of grain far-infrared drying device developed by our unit. It includes a lower base, a far-infrared drying section, a grain discharge section, a hot air drying section, a grain storage section, an exhaust mechanism and a hoist. A cold and hot air mixing chamber is arranged on one side of the section and communicates with the hot air inlet provided on the shell of the far-infrared drying section. When drying, the hot air from the cylindrical far-infrared radiator and the cold air from the air distribution port are mixed in the hot and cold air mixing chamber, and then enter the infrared drying section through the hot air inlet, and pass along the wind deflector. It flows to the middle of the far-infrared drying section, and enters the hot air drying section upwards. In the hot air drying section, the hot air passes through the mesh plate on the supporting trapezoidal mesh frame, passes through the grain layer and enters the exhaust mesh cylinder. Under the action of the axial flow fan, Exhaust the humid air outside the far-infrared drying device.

After practice tests, the above-mentioned far-infrared drying device does not pass through the mesh plate and the grain layer well after the hot air generated by the oil furnace is mixed with the cold air in the hot and cold air mixing chamber, and then enters the infrared drying section through the hot air inlet. Most of them will go up along the gap between the mesh plate and the shell of the hot air drying section, so the grains cannot be dried well in the hot air drying section, and the cylinder type can not be fully utilized. There is a certain waste of heat energy in the residual heat energy discharged by the far-infrared radiator.

Contents of the invention

The technical problem to be solved by the present invention is to provide a grain circulation dryer, which has the advantages of high drying efficiency and thermal efficiency, low energy consumption, high thermal energy utilization rate, sufficient and uniform drying, low drying cost, uniform temperature, and safety.

Technical scheme of the present invention is as follows:

A grain circulation dryer, comprising a radiation drying section, a grain discharge section, a hot air drying section and a grain storage section arranged on a base in sequence from bottom to top, and a There is a material circulation conveying device, a heat source capable of generating heat medium is connected to one side of the radiation drying section, and an induced draft fan and an air mixing chamber are respectively arranged on both sides of the hot air drying section, and the inlet of the mixing air chamber is connected with the heat medium in the radiation drying section. The outlet is connected, and the outlet of the air mixing chamber is connected with the induced draft fan through the hot air drying section.

Preferably, the radiation drying section includes a thin-layer radiation drying structure, and the thin-layer radiation drying structure includes two grain-sliding boards arranged in an inverted "eight" shape, and a cylinder is arranged between the two grain-sliding boards. shape infrared radiator.

Preferably, the hot air drying section is formed by overlapping and connecting multiple sections.

Preferably, each section of the hot air drying section includes two sets of flow-limiting thin-layer drying structures, and each set of flow-limiting thin-layer drying structures includes two mesh plates arranged in an inverted "eight" shape, and between the two mesh plates There is an exhaust duct in the middle, and the mesh plate and the exhaust duct are covered with mesh holes. The outer space of the two mesh plates in each hot air drying section communicates with the outlet of the mixed air chamber. The grain between the perforated plates presents a hollow "diamond shape" through the exhaust duct.

Preferably, an air distribution port is provided outside the lower part of the air mixing chamber, and an insert plate for adjusting the size of the opening is provided in the air distribution port.

Preferably, the induced draft fan is installed on one side of the hot air drying section through an air collecting hood, and the air collecting hood communicates with the exhaust duct.

Preferably, the grain discharge section includes two groups of symmetrically arranged grain discharge devices, each group of grain discharge devices is composed of a grain discharge hopper and a trough-shaped grain discharge wheel arranged at the outlet of the grain discharge hopper.

Preferably, the grain storage section is sequentially connected by the top grain storage section, the general grain storage section and the bottom grain storage section, and there are two sets of limiters arranged in an inverted "eight" shape symmetrically in the bottom grain storage section. Flow board.

Preferably, the material circulation conveying device includes a lower auger located in the base below the outlet of the radiation drying section, an upper auger is provided at the upper end of the grain storage section, and a lower auger and a connecting auger are provided on one side of the base. The hoist of the upper auger, one end of the lower auger communicates with the feed port of the hoist through a distribution nozzle.

The beneficial effects of the present invention are:

1. Through the radiation drying section, it can absorb part of the heat energy in the high-temperature heat medium generated by the heat source, and perform directional radiation heating and drying on the grain; through the hot air drying section, it can absorb and use the remaining energy of the heat medium to dry the grain with hot air, so that the equipment can The organic combination of hot air drying and radiation drying makes full use of heat medium energy in both high-grade and low-grade, high thermal efficiency, low energy consumption, and sufficient and uniform drying.

2. The present invention can be converted to ordinary hot air drying when the temperature of the heat medium provided by the heat source is low, avoiding the disadvantages of infrared drying in some occasions. Therefore, the present invention can realize two operation modes of independent hot air drying and hot air radiation combined drying.

3. The hot air drying section of the present invention adopts a thin-layer flow-limiting drying structure, which makes the grains in a hollow diamond shape, realizes thin-layer cross-flow hot air drying, and avoids the disadvantages of deep-layer drying such as large air resistance and local moisture absorption.

4. The radiation drying section of the present invention makes the grains flow in the shape of a waterfall on the grain sliding plate, and is uniformly heated by infrared radiation, which improves the moisture uniformity of the grains and has a high-quality effect of "imitating nature" like drying in the sun.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a right side view of Fig. 1 .

Fig. 3 is a left side view of Fig. 1 .

Fig. 4 is a structural schematic diagram of the radiation drying section and the base.

In the figure: base 1, radiation drying section 2, heat source 3, grain discharge section 4, air collecting hood 5, induced draft fan 6, hot air drying section 7, bottom grain storage section 8, general grain storage section 9, top grain storage section 10 , upper auger 11, hoist 12, temperature sensor 13, air mixing chamber 14, air distribution port 15, lower auger 16, inserting plate 17, grain sliding plate 18, grain discharge wheel 19, grain discharge hopper 20, exhaust duct 21, mesh plate 22, flow limiting plate 23, material distribution nozzle 24, flashboard 25, grain discharge motor 26, chain transmission mechanism 27, infrared radiator 28, infrared paint layer 29.

Detailed ways

Example 1

As shown in FIG. 1 , the grain circulation dryer includes a base 1 on which a radiation drying section 2 , a grain discharge section 4 , a hot air drying section 7 and a grain storage section are sequentially arranged from bottom to top. A material circulation conveying device is provided between the discharge port of the radiation drying section 2 and the feed port of the grain storage section. The grain storage section is formed by sequentially connecting the top grain storage section 10, the general grain storage section 9 and the bottom grain storage section 8 from top to bottom, and the general grain storage section 9 is formed by overlapping and connecting multiple sections. , the general grain storage section 9 in the present embodiment is formed by superposition of seven sections.

Referring to Fig. 1 and Fig. 2, the hot air drying section 7 is composed of multiple sections superimposed and connected, and this embodiment takes three sections as an example without limitation. Each section of hot air drying section 7 includes a housing and two groups of flow-limiting thin-layer drying structures symmetrically arranged in the housing. Each group of flow-limiting thin-layer drying structure includes two mesh plates 22 arranged in an inverted "eight" shape, and an exhaust duct 21 is respectively arranged in the middle between the two mesh plates 22, and the exhaust duct 21 is a round pipe or Square tube shape, this embodiment takes round tube as an example. The mesh plate 22 and the exhaust duct 21 are covered with mesh holes, and the outer space of the two mesh plates 22 in each section of the hot air drying section 7 communicates with the outlet of the air mixing chamber 14 on one side of the hot air drying section 7. The grain between the two mesh plates 22 presents a hollow "diamond" through the exhaust duct 21. The other side corresponding to the air mixing chamber 14 on the hot air drying section 7 is provided with an induced draft fan 6, and the induced draft fan 6 is installed on the outside of the hot air drying section 7 through an air collecting hood 5, and the described air collecting hood 5 and the exhaust The air ducts 21 are connected.

Referring to Fig. 4, the radiation drying section 2 includes a thin-layer radiation drying structure, and the thin-layer radiation drying structure includes two grain-sliding boards 18 arranged in an inverted "eight" shape, and between the two grain-sliding boards 18 The middle part is provided with a cylindrical infrared radiator 28, and an infrared coating layer 29 is provided on the outer surface of the cylinder of the infrared radiator 28. As preferably, the thickness of the infrared coating layer 29 is 70-100 μm, and the infrared coating layer 29 can absorb heat source Part of the energy generated produces infrared radiation for infrared drying of the grain. In the thin-layer radiation drying structure, the grain flows down along the two grain-sliding plates 18 like a waterfall, receives the radiation of the infrared radiator 28 to heat evenly, and finally falls into the lower auger 16 of the material circulation conveying device.

Referring to Fig. 2 and Fig. 3, the grain discharge section 4 includes two sets of grain discharge devices symmetrically arranged in the shell of the grain discharge section 4, and each group of grain discharge devices is composed of a grain discharge bucket 20 and a grain discharge bucket 20 outlet. The trough-shaped grain row wheel 19 at the place constitutes. The upper mouth of the grain discharge hopper 20 corresponds to the outlet of the flow-limiting thin-layer drying structure located in the hot air drying section 7 of the bottom layer, that is, the lower opening of the two mesh plates 22, and the outlet of the grain discharge hopper 20 is connected to the grain slipping plate 18 of the radiation drying section. Catchy corresponding. A grain discharge motor 26 is installed inside the casing of the radiation drying section 2, and the output shaft of the grain discharge motor 26 is supported on the casing of the radiation drying section 2, and the axle of the grain discharge wheel 19 passes through the output shaft of the grain discharge motor 26. Chain transmission mechanism 27 is connected.

In the bottom grain storage section 8, two sets of flow limiting plates 23 arranged in an inverted "eight" shape are arranged symmetrically. catchy one-to-one correspondence.

Referring to Fig. 1 and Fig. 4, a heat source 3 communicating with an infrared radiator 28 for generating heat medium is fixed on one side of the radiation drying section 2, and the heat source 3 can be an oil furnace, a gas furnace, a hot blast furnace or other capable of generating high temperature As for the flue gas device, as a preference, the heat source 3 in this embodiment is an oil burner. The inlet of the air mixing chamber 14 communicates with the outlet end of the infrared radiator 28. An air distribution port 15 is provided outside the lower part of the air mixing chamber 14, an insert plate 17 is provided in the air distribution port 15, and an air distribution port 17 is arranged on the upper part of the air mixing chamber 14. There is a temperature sensor 13, so that according to the temperature of the hot air entering the hot air drying section 7, the flue gas temperature in the air mixing chamber 14 can be adjusted by changing the insertion depth of the flashboard 17.

The material circulation conveying device includes a lower auger 16 arranged in the base 1, a hoist 12 vertically arranged on one side of the base 1, and an upper auger 11 at the upper end of the top grain storage section 10. Wherein the lower auger 16 is located at the bottom opening of the corresponding radiation drying section 2 outlets in the base 1, that is, at the bottom of the two grain sliding plates 18, and the lower auger 16 is fixed with a distributing nozzle 24 near the end of the elevator 12. There are two material outlets on the nozzle 24 and two rams 25 for selecting the material outlets are symmetrically arranged, one of the material outlets is connected with the circulation feed port of the hoist 12, and the other material outlet is used for drying, normally Drain the grain. The flashboard 25 can be operated independently and is used to control the switch of the material outlet. Described upper auger 11 is installed on the top floor grain storage section 10 along the horizontal direction, and upper auger 11 one end is connected with the discharge port of elevator 12 upper ends, and the other end connects the feed inlet of top floor grain storage section 10.

During work, start the induced draft fan 6, the heat source 3 and the hoist 12, and the grain is transported to the drying equipment by the hoist 12 and the upper auger 11, and fills up the grain storage section and the hot air drying section 7, and the grain follows the restrictor plate 23 to Down flow, until filling between the paired mesh plates 22 and the grain hopper 20. Start the grain discharge motor 26, and the grain moves down to the radiation drying section 2 under the action of the grain discharge wheel 19 and its own gravity; Heat medium namely high-temperature flue gas enters infrared radiator 28 first, makes it produce infrared radiation, can be subjected to the infrared radiation that infrared radiator 28 excites like this when grain slides down, carries out infrared drying. The high-temperature flue gas enters the air mixing chamber 14 after passing through the infrared radiator 28, and adjusts the opening size of the air distribution port 15 through the insert plate 17 according to the value of the temperature sensor 13, so that the hot air temperature suitable for hot air drying is formed in the air mixing chamber 14, and the hot air simultaneously Enter the outside of the paired mesh plates 22 in the multi-stage hot air drying section 7. Under the action of the induced draft fan 6, the hot air passes through the mesh plates 22 and the grain layer in turn and enters the exhaust duct 21, and is discharged through the air collecting hood 5 for drying. Outside the equipment, the hot-air drying to grain has just been completed in the hot-air drying section 7 like this. Grain enters the lower auger 16 after hot air drying and infrared drying in turn, enters the hoist 12 by the lower auger 16 through the distributing nozzle 24, and then enters the top grain storage section 10 through the upper auger 11 for circulation drying. When the grain after circulation drying meets the dehydration requirement, the material outlet can be changed through the shutter 25 of the distribution nozzle 24, and the grain can be discharged and stored.

As a preference, due to the temperature requirements of the infrared coating layer 29, when the temperature of the hot air provided by the heat source 3 is lower than 180°C, the present invention only dries the grain by hot air convection; when the temperature of the hot air is higher than 180°C, it belongs to hot air convection Combination drying with infrared radiation.

Example 2

As shown in Fig. 1-Fig. 3, the structure of this embodiment is basically the same as that of Embodiment 1, and the difference is: there is no infrared coating layer 29 on the outer surface of the tube of the radiator 28 in the radiation drying section 2, and all the other structures are the same as in Embodiment 1. The dryer is only hot air convection drying for grain.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (9)

1. A grain circulation dryer, which is characterized in that: it includes a radiation drying section, a grain discharge section, a hot air drying section and a grain storage section arranged on the base from bottom to top in sequence, and the outlet of the radiation drying section and the grain storage section There is a material circulation conveying device between the feed inlets, a heat source capable of generating heat medium is connected to one side of the radiation drying section, and an induced draft fan and a mixing chamber are respectively arranged on both sides of the hot air drying section. The heat medium outlet of the radiation drying section is connected, and the outlet of the air mixing chamber is connected with the induced draft fan through the hot air drying section. 2. A grain circulation dryer according to claim 1, characterized in that: said radiation drying section includes a thin-layer radiation drying structure, and said thin-layer radiation drying structure includes two pieces arranged in an inverted "eight" shape. The grain sliding board is provided with a cylindrical infrared radiator between the two grain sliding boards. 3. A grain circulation dryer according to claim 1, characterized in that: the hot air drying section is formed by overlapping and connecting multiple sections. 4. A grain circulation dryer according to claim 3, characterized in that: each hot air drying section includes two groups of flow-limiting thin-layer drying structures, and each group of flow-limiting thin-layer drying structures includes two pieces in the shape of an inverted "eight" The mesh plate arranged in the shape of "" has an exhaust duct in the middle between the two mesh plates. The mesh plate and the exhaust duct are covered with mesh holes, and each hot air drying section is located in the The outer space of the air-mixing chamber communicates with the outlet of the air-mixing chamber, and the grain between the two mesh plates presents a hollow "diamond shape" through the exhaust duct. 5. A grain circulation dryer according to claim 1, characterized in that: an air distribution port is provided on the outside of the lower part of the air mixing chamber, and an insert plate that can adjust the size of the opening is provided in the air distribution port. 6. A grain circulation dryer according to claim 4, characterized in that: the induced draft fan is installed on one side of the hot air drying section through an air collecting hood, and the air collecting hood communicates with the exhaust duct. 7. A grain circulation dryer according to claim 1, characterized in that: the grain discharge section includes two groups of grain discharge devices symmetrically arranged, each group of grain discharge devices is composed of a grain discharge hopper and a The trough-shaped grain row wheel at the exit of the grain hopper is formed. 8. A grain circulation dryer according to claim 1, characterized in that: the grain storage section is sequentially connected by the top grain storage section, the general grain storage section and the bottom grain storage section, and the grain storage section at the bottom layer There are two groups of flow limiting plates arranged in an inverted "eight" shape symmetrically in the section. 9. A grain circulation dryer according to claim 1, characterized in that: the material circulation conveying device includes a lower auger located in the base below the discharge port of the radiation drying section, and the upper end of the grain storage section is set There is an upper auger, and a hoist connecting the lower auger and the upper auger is provided on one side of the base, and one end of the lower auger communicates with the feed port of the hoist through a material distribution nozzle.