Energy-saving drum dryer for bean dregs

Abstract

The application discloses a heat-preservation and energy-saving bean dregs roller dryer, which comprises a roller, a combustion furnace, a blower, an air guide fan and a heat exchanger, wherein the roller comprises an inner layer and an outer layer, and a gap is formed between the inner layer and the outer layer to form an inner-outer sandwich layer; the hearth of the combustion furnace extends into the roller, and the combustion chamber of the combustion furnace is communicated with the blower and blows heat into the hearth; the head of the outer circumference of the outer layer is provided with a plurality of head branch pipes which are distributed in a circumferential direction, and the other ends of the head branch pipes are communicated with the air guide fan; and the tail of the outer circumference of the outer layer is provided with a plurality of tail branch pipes which are distributed in a circumferential direction and discharge hot steam. The application fully recycles the heat energy of the flue gas of the combustion furnace and the heat energy of the saturated hot steam flow in the tail of the roller, forms the inner wall thermal laminar flow of the roller and the hot steam flow of the inner-outer sandwich layer of the roller, and additionally forms a three-layer heat preservation structure of the stone wool heat preservation layer, so that the energy-saving effect is good.

Description

Technical Field

[0001] This invention relates to a drum dryer, and more particularly to a heat-insulating and energy-saving drum dryer for soybean residue. Background Technology

[0002] Rotary drum dryers are a type of traditional drying equipment. They are reliable in operation, highly flexible in operation, adaptable, and have a large processing capacity. They are widely used in metallurgy, building materials, chemical industry, coal washing, fertilizer, ore, sand, clay, kaolin, sugar and other fields. The diameter is generally Φ1000-Φ4000, and the length is determined according to the drying requirements.

[0003] Traditional rotary drum dryer production lines are shown in the attached image. Figure 1 As shown, the dryer mainly consists of a rotating drum, induced draft dust removal equipment, lifting plates, transmission device, conveying equipment, hot air blower, reducer, and support device. The drum is covered with an asbestos insulation layer. Its working principle is as follows: After wet material is fed into the dryer from the higher end, it is dispersed and scattered within the drum by the evenly distributed lifting plates on the inner wall of the drum. It then comes into full contact with the concurrent (co-current or counter-current) hot air for drying and heat transfer. During the drying process, the material, under the action of the inclined drum, lifting plates, and hot airflow, moves controllably to the tail end of the dryer through the drum's rotation, and is discharged as the dried product through the discharge valve. The saturated steam at the tail end is discharged into the atmosphere after passing through a cyclone separator and dust removal. The drying hot airflow is generated by the combustion furnace of the hot air blower through heat exchange tubes and blown into the dryer drum by a blower. The hot airflow mixes with the moisture in the material to form a hot steam flow, which is then discharged into the atmosphere after dust removal by the induced draft device at the tail end.

[0004] When drying soybean residue in a rotary drum dryer, the moisture content of wet soybean residue is generally above 85%, and soybean residue is not resistant to high temperatures, and will burn at temperatures above 220 degrees Celsius. The temperature inside the combustion furnace generally needs to reach above 350 degrees Celsius, and the residue is blown into the drum after heat exchange to achieve the desired drying effect. Improper temperature control will lead to the soybean residue burning. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of the existing technology that the soybean residue is easily burned due to excessive temperature during the drying process, and to provide a heat-insulating and energy-saving soybean residue drum dryer that makes it easy to control the dryness and humidity of soybean residue and prevents burning.

[0006] The technical solution adopted by this invention to solve its technical problem is a heat-insulating and energy-saving soybean residue drum dryer, comprising a drum, a combustion furnace, a blower, an induced draft fan, and a heat exchanger. The drum comprises an inner drum layer and an outer drum layer, with a gap between the inner and outer drum layers forming an inner and outer sandwich. The furnace chamber of the combustion furnace extends into the drum, and the combustion chamber of the combustion furnace is connected to the blower, blowing heat into the furnace chamber. The head of the outer circumference of the outer drum layer has multiple circumferentially distributed head branch pipes, the other end of which is connected to the induced draft fan. The tail of the outer circumference of the outer drum layer also has multiple circumferentially distributed tail branch pipes for discharging hot steam.

[0007] Furthermore, the roller also includes a head retaining ring nested in the outer layer of the roller, and the diameter of the head retaining ring is larger than the diameter of the outer layer of the roller. The head retaining ring has an opening and the opening is connected to the induced draft fan through a pipe. The head branch pipe is connected to the head retaining ring.

[0008] Furthermore, the roller also includes a tail retaining ring nested in the outer layer of the roller, and the diameter of the tail retaining ring is larger than the diameter of the outer layer of the roller. The tail retaining ring has an opening that is connected to the outside through a pipe and discharges hot steam. The tail branch pipe is connected to the tail retaining ring.

[0009] Furthermore, a sealing ring is provided between the head retaining ring, the tail retaining ring, and the outer layer of the roller.

[0010] Furthermore, the furnace has a flue gas discharge branch pipe, and a flue gas heat energy recovery station is provided on the outside of the drum. The flue gas discharge branch pipe passes through the outer layer and the inner layer of the drum and communicates with the flue gas heat energy recovery station. The flue gas heat energy recovery station has a flue gas discharge main pipe, which is connected to the heat exchanger. The heat energy carried by the flue gas passes through the heat exchanger and sends hot air into the head of the drum, forming a thermal laminar flow on the inner wall of the drum.

[0011] Furthermore, the inner head of the drum is provided with an inner lining, and the inner lining is spaced apart from the furnace chamber.

[0012] This invention offers the following beneficial technical effects: It fully utilizes the flue gas heat energy from the combustion furnace and the saturated hot steam flow heat energy at the tail end of the drying drum, forming a laminar flow on the inner wall of the drum and a hot steam flow in the inner and outer layers of the drum. The addition of a three-layer insulation structure with an asbestos insulation layer reduces the large temperature gradient between the center of the drum and the inner wall. It also utilizes residual heat to preheat the material to be dried, reducing energy waste and heat emissions, making the dryer more efficient, energy-saving, and environmentally friendly, resulting in more significant social and economic benefits. Furthermore, the moisture content of the soybean residue is easily controlled, preventing scorching. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a conventional drum dryer; Figure 2 This is a partial structural schematic diagram of an embodiment of the heat-insulating and energy-saving soybean residue drum dryer of the present invention; Figure 3 This is a schematic diagram of the overall structure of an embodiment of the heat-insulating and energy-saving soybean residue drum dryer of the present invention; Figure 4 This is a schematic diagram of the tail ring structure of an embodiment of the heat-insulating and energy-saving soybean residue drum dryer of the present invention; Figure 5 This is a schematic diagram of the head fixing ring structure of an embodiment of the heat-insulating and energy-saving soybean residue drum dryer of the present invention; Figure 6 This is a schematic diagram of the flue gas heat recovery ring structure of the heat-insulating and energy-saving soybean residue drum dryer of the present invention.

[0014] Explanation of reference numerals in the attached figures: 1. Drum; 11. Outer layer of drum; 12. Inner layer of drum; 13. Head branch pipe; 14. Tail branch pipe; 15. Head retaining ring; 16. Tail retaining ring; 17. Sealing ring; 18. Lining; 2. Combustion furnace; 21. Furnace chamber; 22. Combustion chamber; 23. Flue gas exhaust branch pipe; 24. Flue gas heat recovery retaining ring; 25. Flue gas exhaust main pipe; 3. Blower; 4. Exhaust fan; 5. Dust removal device; 6. Material preheating device; 7. Heat exchanger. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0016] Reference Figures 2 to 6 This embodiment includes a drum 1, a combustion furnace 2, a blower 3, a heat exchanger 7, an induced draft fan 4, a dust removal device 5, and a material preheating device 6. The drum 1 consists of an inner drum layer 12 and an outer drum layer 11, with a certain gap between them to form an inner and outer sandwich. The size of the gap is determined by the flow rate of hot steam at the tail of the dryer, generally around 5-10 cm. The outer drum layer 11 is made of stainless steel or carbon steel, and the inner drum layer 12 is made of stainless steel.

[0017] The combustion furnace 2 is equipped with a furnace chamber 21, and the combustion furnace 2 also has a combustion chamber 22 inside. The furnace chamber 21 is designed as a cylindrical inner liner and is extended to extend directly into two-thirds of the inside of the drum 1. The blower 3 is connected to the combustion chamber 22. After the fuel is put into the combustion chamber 22 for combustion, the heat of the combustion chamber 22 is directly blown into the drum 1 through the blower 3, and the temperature of the furnace chamber 21 is controlled at about 220 degrees Celsius.

[0018] Twelve head branch pipes 13 are uniformly welded to the circumferential surface of the outer layer 11 of the drum near the combustion furnace 2. Simultaneously, a head retaining ring 15 is nested on the outer circumferential surface of the outer layer 11. The diameter of the head retaining ring 15 is larger than that of the outer layer 11. The head retaining ring 15 has an opening that connects to the induced draft fan 4 via a pipe, thereby allowing the head branch pipes 13 to connect to the induced draft fan 4 through the opening and the pipe. Similarly, twelve tail branch pipes 14 are uniformly welded to the circumferential surface of the outer layer 11 away from the combustion furnace 2. Simultaneously, a tail retaining ring 16 is nested on the outer circumferential surface of the outer layer 11. The diameter of the tail retaining ring 16 is larger than that of the outer layer 11. The tail retaining ring 16 also has an opening that connects to the material preheating device 6 via a pipe, thereby allowing the tail branch pipes 14 to connect to the material preheating device 6 through the opening and the pipe. The tail of the material preheating device 6 has an outlet for discharging hot air. Furthermore, a high-temperature resistant and wear-resistant sealing ring 17 is provided between the head retaining ring 15, the tail retaining ring 16, and the outer layer 11 of the drum to prevent hot steam leakage. During the drying process of wet soybean residue, hot steam is generated due to the high temperature of the combustion furnace 2. Under the action of the induced draft fan 4, the hot steam flows from the tail of the drum 1 through a pipe into the head retaining ring 15, then through the head retaining ring 15 into the head branch pipe 13, and into the gap between the inner and outer layers. Under the action of the induced draft fan 4, it flows from the tail branch pipe 14 into the tail retaining ring 16, and then exits from the tail retaining ring 16 and enters the material preheating device 6 through a pipe. The hot steam and the asbestos insulation layer covering the drum 1 together provide a double insulation effect, which multiplies the insulation capacity and greatly reduces heat loss. The hot steam discharged from the tail is introduced into the material preheating device 6 and then utilized to preheat the material to be dried.

[0019] Six flue gas discharge branch pipes 23, evenly distributed in a circular pattern, are welded to the outer circumference of the furnace chamber 21. A flue gas heat recovery stationary ring 24 is provided on the outer side of the drum 1. The flue gas discharge branch pipes 23 pass through the outer layer 11 and the inner layer 12 of the drum and communicate with the flue gas heat recovery stationary ring 24. The flue gas heat recovery stationary ring 24 has a flue gas discharge main pipe 25, which is connected to the dust removal device 5. A heat exchanger 7 is connected to the flue gas discharge main pipe 25. The heat generated by the exchange is sent to the head of the drum 1 through a pipe, forming a thermal laminar flow on the inner wall of the drum 1. The flue gas generated by combustion passes through the flue gas discharge branch pipes 23, collects in the flue gas heat recovery stationary ring 24, and then is discharged into the flue gas main pipe. After being dusted by the dust removal device 5, it is discharged into the atmosphere.

[0020] The inner layer 12 of the drum is provided with a lining 18, and the lining 18 and the furnace chamber 21 are spaced apart to form a separate layer. The length of the lining 18 should preferably exceed the length of the flame center in the furnace chamber 21, and its diameter should be larger than the diameter of the furnace chamber 21, with a gap of about 10-20 cm. This reduces the temperature gradient and controls the temperature above 200 degrees Celsius, preventing the soybean residue from burning in direct contact.

[0021] In addition, the flame temperature in the furnace 21 is above 220 degrees Celsius. After transmission loss, the flue gas temperature in the pipeline is 180-200 degrees Celsius. This part of the flue gas heat energy can be utilized by adding a heat exchanger 7 in the pipeline. The heat exchange rate is designed to recover and utilize the waste heat of the flue gas with a heat exchange rate of 70%-80%. The temperature of the recovered heat energy is about 120-140 degrees Celsius. This heat energy is introduced into the space between the inner layer 12 and the inner lining 18 of the drum, preferably near the head of the inner layer of the drum 1. Since the drum 1 is rotating, a thermal laminar flow is formed on the inner wall of the drum 1, which further reduces the temperature difference between the center of the drum 1 and the inner wall of the drum, and maintains the stability of the temperature gradient inside the dryer drum 1. This helps to prevent uneven drying, clumping, and burning of materials during the drying process, and prevents heat from being dissipated by the drum body, thus playing a further role in heat preservation.

[0022] The above are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent changes made to the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A heat-insulating and energy-saving soybean residue drum dryer, comprising a drum (1), a combustion furnace (2), a blower (3), an induced draft fan (4), and a heat exchanger (7), characterized in that, The drum (1) includes an inner drum layer (12) and an outer drum layer (11), and there is a gap between the inner drum layer (12) and the outer drum layer (11) to form an inner and outer sandwich layer. The combustion furnace (2) is provided with a furnace chamber (21), and the combustion furnace (2) has a combustion chamber (22) inside. The furnace chamber (21) is designed as a cylindrical inner liner and extended to two-thirds of the way into the inside of the drum (1). The blower (3) is connected to the combustion chamber (22). After the fuel is put into the combustion chamber (22) for combustion, the heat of the combustion chamber (22) is directly blown into the drum (1) by the blower (3). The head of the outer circumference of the outer drum layer (11) has multiple head branch pipes (13) distributed in a circular pattern. The other end of each head branch pipe (13) is connected to the induced draft fan (4). The tail of the outer circumference of the outer drum layer (11) also has multiple tail branch pipes (14) distributed in a circular pattern for discharging hot steam. The roller (1) also includes a head retaining ring (15) nested in the outer layer (11) of the roller, and the diameter of the head retaining ring (15) is larger than the diameter of the outer layer (11) of the roller. The head retaining ring (15) has an opening and the opening is connected to the blower (4) through a pipe. The head branch pipe (13) is connected to the head retaining ring (15). The roller (1) further includes a tail retaining ring (16) nested in the outer layer (11) of the roller, and the diameter of the tail retaining ring (16) is larger than the diameter of the outer layer (11) of the roller. The tail retaining ring (16) has an opening and the opening is connected to the outside through a pipe and discharges hot steam. The tail branch pipe (14) is connected to the tail retaining ring (16). The furnace (21) has a flue gas discharge branch pipe (23), and a flue gas heat energy recovery stationary ring (24) is provided on the outside of the drum (1). The flue gas discharge branch pipe (23) passes through the outer layer (11) and the inner layer (12) of the drum and communicates with the flue gas heat energy recovery stationary ring (24). The flue gas heat energy recovery stationary ring (24) has a flue gas discharge main pipe (25). The flue gas discharge main pipe (25) is connected to the heat exchanger (7). The heat energy carried by the flue gas passes through the heat exchanger (7) and sends hot air into the head of the drum (1) to form a hot laminar flow on the inner wall of the drum. The inner layer (12) of the drum is provided with an inner lining (18) at its head, and the inner lining (18) is spaced apart from the furnace (21); The length of the inner lining (18) exceeds the length of the flame center of the furnace (21), and the diameter of the inner lining (18) is greater than the diameter of the furnace (21).

2. The heat-insulating and energy-saving soybean residue drum dryer according to claim 1, characterized in that, A sealing ring (17) is provided between the head retaining ring (15), the tail retaining ring (16), and the outer layer (11) of the roller.

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