Cooling device for compound fertilizer

Abstract

The utility model discloses a cooling device for compound fertilizer, and belongs to the technical field of compound fertilizer. Comprising a dust treatment structure, a screening structure, a powder flow heat exchanger, a first bucket elevator, a three-way material distribution valve, a cooling roller, a first dehumidifier, a bypass conveying belt, a second dehumidifier and a dehumidification air blower, the screening structure is connected with the powder flow heat exchanger, and tail gas outlets of the screening structure and the powder flow heat exchanger are connected with the dust treatment structure; the first bucket elevator is connected with the three-way material distribution valve; the three-way material distributing valve outputs in two ways, one way is output to the cooling roller, and the other way is output to the bypass conveying belt; an air inlet of the cooling roller is connected with the first dehumidifier, a tail gas outlet of the cooling roller is connected with the dust treatment structure, and a discharge port of the cooling roller is connected with the screening structure; the discharging end of the bypass conveying belt is connected with the screening structure. The first dehumidifier, the second dehumidifier and the powder flow heat exchanger are connected with the cooling water circulation system; the dehumidification air blower, the second dehumidifier and an air inlet of the powder flow heat exchanger are sequentially connected.

Description

Technical Field

[0001] This utility model belongs to the field of compound fertilizer technology, and specifically relates to a cooling device for compound fertilizer. Background Technology

[0002] High-tower compound fertilizer adopts melt urea carrier tower granulation technology, which uses molten urea and raw materials such as phosphorus and potassium, which are fully mixed and sprayed down from the top of the tower, and then naturally cooled and granulated.

[0003] For example, patent application number CN201720909790.4 discloses a high-tower compound fertilizer production system. The system is arranged in three floors, including a granulation device, a return conveyor belt, and a bucket elevator running sequentially from bottom to top through the first, second, and third floors; a drying device, a cooling device, a first-floor drum screen, and a crushing device on the first floor; a second-floor drum screen and a coating device on the second floor; and a third-floor drum screen on the third floor. The discharge port at the bottom of the granulation device, the drying device, the first-floor drum screen, and the cooling device are connected via... The conveyor belts are connected in sequence; the outlet of the cooling device is connected to the inlet of the third-floor drum screen via a bucket elevator; the outlet of the third-floor drum screen, the second-floor drum screen, and the coating device are connected in sequence via conveyor belts, and their coarse material outlet is connected to the inlet of the crushing device via a conveyor belt; the outlet of the crushing device, the fine material outlet of the first-floor drum screen, and the fine material outlet of the second-floor drum screen are all connected to the return outlet of the granulation device via a return belt; the screening capacity of the third-floor drum screen is greater than that of the first-floor drum screen.

[0004] Cooling devices are used in the preparation of high-tower compound fertilizers. Existing technology uses powder flow heat exchangers to cool the compound fertilizer. For example, patent application number CN201720756312.4 discloses a production system for preventing compound fertilizer agglomeration. This system includes a powder flow heat exchanger connected to a coating machine, which is connected to a bulk material silo, which is connected to a packaging machine. This utility model uses a powder flow cooling system instead of a drum cooler. For example, patent application number CN201920888157.0 discloses a production system for preventing compound fertilizer from caking, including a powder flow heat exchanger; a coating machine connected to the powder flow heat exchanger via pipeline; a bulk material silo connected to the coating machine via belt conveyor; and a packaging machine connected to the bulk material silo via pipeline; wherein a drum screen is provided between the powder flow heat exchanger and the coating machine; the powder flow heat exchanger includes a feed hopper, and an agitator that moves vertically within the feed hopper; and a discharge device fixedly connected to the bottom of the feed hopper.

[0005] The applicant discovered that compound fertilizer occasionally caking during actual production. After analysis, the applicant identified the following possible reasons: 1. The powder flow heat exchanger is sometimes unable to reduce the product temperature below 40℃ (e.g., in summer or when the heat exchanger is not properly adjusted for operation). 2. The powder flow heat exchanger consumes a large amount of cold air during cooling; if the cold air has a high moisture content, it will result in a high moisture content in the product, also causing caking. Summary of the Invention

[0006] To address the aforementioned problems, this utility model provides a cooling device for compound fertilizer. A cooling drum is installed before the screening structure. Normally, the compound fertilizer does not pass through the cooling drum for cooling. However, if the cooling effect of the powder flow heat exchanger is insufficient, the compound fertilizer is first cooled by the cooling drum, and then by the powder flow heat exchanger. The air intake for both the powder flow heat exchanger and the cooling drum is dehumidified by a dehumidifier to ensure that the moisture content of the compound fertilizer does not exceed the standard. This reduces the possibility of compound fertilizer caking. The technical solution is as follows:

[0007] This utility model embodiment provides a cooling device for compound fertilizer, including a dust treatment structure, a screening structure 7, and a powder flow heat exchanger 9. The outlet of the screening structure 7 is connected to the inlet of the powder flow heat exchanger 9. The exhaust outlets of both the screening structure 7 and the powder flow heat exchanger 9 are connected to the dust treatment structure via pipelines. The cooling water outlet and cooling water inlet of the powder flow heat exchanger 9 are connected to a cooling water circulation system via pipelines. The cooling device also includes a first bucket elevator 1, a three-way distribution valve 2, a cooling drum 3, a first dehumidifier 5, a bypass conveyor belt 4, a second dehumidifier 11, and a dehumidifying blower 10. The inlet of the first bucket elevator 1 is connected to the compound fertilizer production device. The outlet of the first dehumidifier 11 is connected to the inlet of the three-way distribution valve 2; the three-way distribution valve 2 outputs two paths, one path to the inlet of the cooling drum 3 and the other path to the inlet of the bypass conveyor belt 4; the air inlet of the cooling drum 3 is connected to the first dehumidifier 5 through a pipeline, its exhaust outlet is connected to the dust treatment structure through a pipeline, and its outlet is connected to the inlet of the screening structure 7; the outlet of the bypass conveyor belt 4 is connected to the inlet of the screening structure 7; the cooling water outlet and cooling water inlet of the first dehumidifier 5 and the second dehumidifier 11 are connected to the cooling water circulation system through pipelines; the air inlets of the dehumidifying blower 10, the second dehumidifier 11 and the powder flow heat exchanger 9 are connected in sequence through pipelines.

[0008] Furthermore, the cooling device in this embodiment of the present invention also includes a second bucket elevator 6; the cooling drum 3 is located directly above the bypass conveyor belt 4, and is arranged obliquely downward along the conveying direction of the bypass conveyor belt 4, so that its discharge can fall directly onto the bypass conveyor belt 4; the feed inlet of the second bucket elevator 6 is connected to the discharge end of the bypass conveyor belt 4, and its discharge outlet is connected to the feed inlet of the screening structure 7.

[0009] The dust treatment structure in this embodiment includes a cyclone separator 12, a bag filter 13, and a fan 14 connected in sequence by pipelines. The air inlet of the cyclone separator 12 is connected to the exhaust outlet of the cooling drum 3, the screening structure 7, and the powder flow heat exchanger 9 by pipelines. The lower part of the powder flow heat exchanger 9 is provided with a pneumatic vibrator. The purge air inlet of the bag filter 13 and the pneumatic vibrator are both connected to the compressed air supply system by pipelines.

[0010] Furthermore, the cooling device in this embodiment of the present invention also includes a third bucket elevator 8; the feed inlet of the third bucket elevator 8 is connected to the discharge outlet of the screening structure 7, and its discharge outlet is connected to the feed inlet at the top of the powder flow heat exchanger 9.

[0011] The beneficial effects of the technical solution provided by this utility model embodiment are as follows: This utility model embodiment provides a cooling device for compound fertilizer. A cooling drum is set before the screening structure (the rotation of the cooling drum can easily cause product crushing, so it is set before screening). Under normal circumstances, the compound fertilizer does not pass through the cooling drum for cooling. If the cooling effect of the powder flow heat exchanger (which has a good cooling effect, and under normal circumstances, only the powder flow heat exchanger is needed for cooling) is not up to standard, the compound fertilizer is first cooled by the cooling drum and then by the powder flow heat exchanger to ensure the cooling effect and keep the temperature of the compound fertilizer below 40℃ (generally below 35℃). The air intake of both the powder flow heat exchanger and the cooling drum is dehumidified by a dehumidifier to ensure that the moisture content of the compound fertilizer does not exceed the standard. The above can reduce the possibility of compound fertilizer caking. The powder flow heat exchanger, the first dehumidifier and the second dehumidifier share a cooling water circulation system, which can reduce the investment in equipment. In addition, the two modes of this patent (with or without the cooling drum) are easy to switch. Attached Figure Description

[0012] Figure 1 This is a schematic block diagram of a cooling device for compound fertilizer provided in an embodiment of this utility model;

[0013] Figure 2 This is a schematic diagram of the dust treatment structure.

[0014] Figure 3 This is a schematic diagram of the structure of a cooling device for compound fertilizer provided in an embodiment of this utility model;

[0015] Figure 4 This is a schematic diagram of a powder flow heat exchanger.

[0016] In the diagram: 1 First bucket elevator, 2 Three-way material distribution valve, 3 Cooling drum, 4 Bypass conveyor belt, 5 First dehumidifier, 6 Second bucket elevator, 7 Screening structure, 8 Third bucket elevator, 9 Powder flow heat exchanger, 10 Dehumidifier blower, 11 Second dehumidifier, 12 Cyclone separator, 13 Bag dust collector, 14 Fan. Detailed Implementation

[0017] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0018] Example 1

[0019] See Figure 1-4Example 1 provides a cooling device for compound fertilizer, which includes a dust treatment structure (for treating exhaust gas), a first bucket elevator 1, a three-way distribution valve 2, a cooling drum 3, a first dehumidifier 5, a bypass conveyor belt 4, a second bucket elevator 6, a screening structure 7, a third bucket elevator 8, a powder flow heat exchanger 9, a second dehumidifier 11, and a dehumidifying blower 10. The feed inlet of the first bucket elevator 1 is connected to the compound fertilizer production device (outputting compound fertilizer) (directly connected, or connected via pipeline or chute, hereinafter the same), and the discharge outlet of the first bucket elevator 1 is connected to the feed inlet of the three-way distribution valve 2. The three-way distribution valve 2 outputs in two paths (selected as needed): one path (cooled by the cooling drum 3) outputs to the feed inlet of the cooling drum 3, and the other path (not cooled by the cooling drum 3) outputs to the feed end of the bypass conveyor belt 4. The air inlet of the cooling drum 3 is connected to the first dehumidifier 5 via a pipeline (for providing dry, cool air), its exhaust outlet is connected to the dust treatment structure via a pipeline, and its discharge port is connected to the inlet of the second bucket elevator 6. The discharge end of the bypass conveyor belt 4 is connected to the inlet of the second bucket elevator 6. Specifically, the cooling drum 3 is located directly above the bypass conveyor belt 4, and it is obliquely downward along the conveying direction of the bypass conveyor belt 4. Its discharge (a dust collection hood can be installed here and connected to the dust treatment structure) can fall directly onto the bypass conveyor belt 4 (either directly or through a pipeline or chute). The discharge port of the second bucket elevator 6 is connected to the inlet of the screening structure 7, and the discharge port of the screening structure 7 is connected to the inlet at the top of the powder flow heat exchanger 9 via the third bucket elevator 8. The discharge port at the bottom of the powder flow heat exchanger 9 is connected to the inlet of the wrapping drum (for wrapping anti-caking oil, etc.). The exhaust outlets of both the screening structure 7 and the powder flow heat exchanger 9 are connected to the dust treatment structure via pipelines. The cooling source for the powder flow heat exchanger 9, the first dehumidifier 5, and the second dehumidifier 11 is cooling water; therefore, their cooling water outlets and inlets are connected to a cooling water circulation system via pipelines to form a circulation. The cooling water circulation system provides cooling water and includes a cooling tower, a circulation tank, and a circulation pump. The air inlets of the dehumidifying blower 10, the second dehumidifier 11, and the powder flow heat exchanger 9 (specifically located at the lower and middle parts of the powder flow heat exchanger 9) are sequentially connected via pipelines (to provide dry, cool air).

[0020] Among them, see Figure 2-3 The dust treatment structure in this embodiment includes a cyclone separator 12, a bag filter 13, and a fan 14 connected in sequence by pipelines. The air inlet of the cyclone separator 12 is connected to the exhaust outlet of the cooling drum 3, the screening structure 7, and the powder flow heat exchanger 9 through pipelines. A pneumatic vibrator is provided at the lower part of the powder flow heat exchanger 9 to prevent compound fertilizer from adhering to the inner wall of the powder flow heat exchanger 9. The purge air inlet and the pneumatic vibrator of the bag filter 13 are both connected to a compressed air supply system (for providing compressed air) through pipelines.

[0021] Example 2

[0022] See Figure 3 Example 2 provides a cooling device for compound fertilizer, whose structure is basically the same as that of Example 1, except that the screening structure 7 in this example includes a fine material drum screen and a coarse material drum screen arranged sequentially. The feed inlet of the fine material drum screen is connected to the discharge outlet of the second bucket elevator 6, its exhaust outlet is connected to the dust treatment structure through a pipeline, its fine material outlet is connected to the return material structure (including the bucket elevator and conveyor belt, etc., with a dust collection hood installed in a suitable location), and its coarse material outlet is connected to the feed inlet of the coarse material drum screen. The exhaust outlet of the coarse material drum screen is connected to the dust treatment structure through a pipeline, its coarse material outlet is connected to the return material structure, and its fine material outlet is connected to the feed inlet of the third bucket elevator 8. The dust outlets of the cyclone separator 12 and the bag filter 13 are connected to the return material structure through a conveyor belt. The return material structure is connected to the compound fertilizer production device.

[0023] Example 3

[0024] Example 3 provides a cooling device for compound fertilizer, which has a structure that is basically the same as that of Example 1, except that the cooling device for compound fertilizer in this example is located in a 150,000-ton compound fertilizer production system.

[0025] In this embodiment, "first", "second", "third" and "fourth" serve only to distinguish and have no other special meaning.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cooling device for compound fertilizer, comprising a dust treatment structure, a screening structure (7), and a powder flow heat exchanger (9), wherein the outlet of the screening structure (7) is connected to the inlet of the powder flow heat exchanger (9), the exhaust outlets of the screening structure (7) and the powder flow heat exchanger (9) are both connected to the dust treatment structure via pipelines, and the cooling water outlet and cooling water inlet of the powder flow heat exchanger (9) are connected to a cooling water circulation system via pipelines; characterized in that, The cooling device also includes a first bucket elevator (1), a three-way feed valve (2), a cooling drum (3), a first dehumidifier (5), a bypass conveyor belt (4), a second dehumidifier (11), and a dehumidifying blower (10). The feed inlet of the first bucket elevator (1) is connected to the compound fertilizer production device, and the discharge outlet of the first bucket elevator (1) is connected to the feed inlet of the three-way feed valve (2). The three-way feed valve (2) outputs two paths: one path outputs to the feed inlet of the cooling drum (3), and the other path outputs to the feed end of the bypass conveyor belt (4). The air inlet of the drum (3) is connected to the first dehumidifier (5) through a pipeline, its exhaust outlet is connected to the dust treatment structure through a pipeline, and its discharge outlet is connected to the feed inlet of the screening structure (7); the discharge end of the bypass conveyor belt (4) is connected to the feed inlet of the screening structure (7); the cooling water outlet and cooling water inlet of the first dehumidifier (5) and the second dehumidifier (11) are connected to the cooling water circulation system through pipelines; the air inlets of the dehumidifying blower (10), the second dehumidifier (11) and the powder flow heat exchanger (9) are connected in sequence through pipelines.

2. The cooling device for compound fertilizer according to claim 1, characterized in that, The cooling device also includes a second bucket elevator (6); the cooling drum (3) is located directly above the bypass conveyor belt (4), and is set obliquely downward along the conveying direction of the bypass conveyor belt (4), and its discharge can fall directly onto the bypass conveyor belt (4); the feed inlet of the second bucket elevator (6) is connected to the discharge end of the bypass conveyor belt (4), and its discharge outlet is connected to the feed inlet of the screening structure (7).

3. The cooling device for compound fertilizer according to claim 1, characterized in that, The dust treatment structure includes a cyclone separator (12), a bag filter (13), and a fan (14) connected in sequence by pipelines. The air inlet of the cyclone separator (12) is connected to the exhaust outlet of the cooling drum (3), the screening structure (7), and the powder flow heat exchanger (9) through pipelines. The lower part of the powder flow heat exchanger (9) is equipped with a pneumatic vibrator. The purge air inlet of the bag filter (13) and the pneumatic vibrator are both connected to the compressed air supply system through pipelines.

4. The cooling device for compound fertilizer according to claim 1, characterized in that, The cooling device also includes a third bucket elevator (8); the feed inlet of the third bucket elevator (8) is connected to the discharge outlet of the screening structure (7), and its discharge outlet is connected to the feed inlet at the top of the powder flow heat exchanger (9).

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