Phosphorite pellet drying furnace with internal communication combustor

Abstract

This utility model provides a phosphate rock powder pellet drying furnace with an internally connected burner, belonging to the technical field of phosphate chemical production equipment. This drying furnace solves the problem of significant heat loss and difficulty in achieving higher quality dried phosphate rock powder pellets in existing technologies by directly connecting the burner's nozzle to its interior. The burner's nozzle is directly connected to the furnace's interior, directly injecting flame into the furnace. The burner's nozzle is connected to the lower part of the furnace, and multiple burners are arranged separately on opposite sides of the furnace. The furnace also includes a first temperature sensor; when the temperature inside the furnace is below a first set value, it electrically controls the burner to increase the flame; when it is above a second set value, it electrically controls the burner to decrease the flame. The burner has a first pneumatic shut-off valve and a second pneumatic shut-off valve connected in series.

Description

Technical Field

[0001] This utility model belongs to the technical field of phosphorus chemical production equipment, and in particular relates to a phosphate rock powder pellet drying furnace with an internally connected burner. Background Technology

[0002] Phosphate rock powder pellets are a product made by processing phosphate rock powder into spherical shapes using a specific process. Currently, the production of yellow phosphorus involves high-grade phosphate rock, especially weathered phosphate rock, which generates a large amount of powder during processing and use. This powder must be pelletized before it can be used in yellow phosphorus production. In existing technologies, the production process of phosphate rock powder pellets includes batching, mixing, pelletizing, and drying. Drying is a crucial process in phosphate rock powder pellet production, and the drying equipment is the key piece of equipment in the phosphate rock powder drying process.

[0003] Chinese utility model patent application publication number CN112556318A discloses a high-efficiency drying device for phosphate rock powder pellet production. The structure of the drying device described in the patent is such that hot air is introduced into the heating pipe from the air inlet chamber on the right and discharged from the exhaust chamber on the left. The hot air is directly discharged, and the residence time in the drying section is short, resulting in poor heating effect on the pellets.

[0004] A mineral powder pellet drying device disclosed in Chinese Utility Model Patent No. CN215002793U features a design where hot air flows into the drying section from the upper row of heating troughs through an air inlet chamber. Because the upper row of heating troughs is blocked on one side of the exhaust chamber, the hot air can only flow downwards to the lower row of heating troughs and then out through the exhaust chamber. This design creates airflow turbulence between the upper and lower rows of heating troughs, allowing the hot air to remain in the drying section for a longer time and thus more thoroughly drying the pellets. Compared to Chinese Utility Model Patent No. CN112556318A, this drying process is more energy-efficient and effective. Furthermore, the hot air discharged from the exhaust chamber carries away the water vapor evaporated from the pellets, ensuring timely removal of the evaporated water vapor from the drying section and further improving the drying effect.

[0005] However, the technical solution described in Chinese utility model patent CN215002793U uses hot air generated by combustion to enter the drying section through the air inlet to dry the mineral powder pellets. Although the thermal efficiency is improved compared to the technical solution described in Chinese utility model patent CN112556318A, the heat loss is still significant, resulting in high energy consumption costs. Moreover, it cannot quickly remove moisture from the surface of the pellets, preventing the mineral powder pellets from quickly forming a relatively dry outer shell. This makes it difficult to prevent internal moisture from diffusing outward and eroding the pellet surface. Therefore, mineral powder pellets dried by using hot air generated by combustion to enter the drying section through the air inlet cannot achieve higher quality. Utility Model Content

[0006] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a phosphate rock powder pellet drying furnace with an internally connected burner, which solves the problem that the heat loss during the drying process of the existing phosphate rock powder pellet drying device is still very large, and the dried phosphate rock powder pellets are difficult to achieve higher quality.

[0007] To achieve the above and other related objectives, this utility model provides a phosphate rock powder pellet drying furnace with an internally connected burner, used to contain phosphate rock powder pellets, and to deliver heat energy into the furnace through the burner to dry the contained phosphate rock powder pellets. The burner's nozzle is directly connected to the interior of the drying furnace, and flames are directly injected into the interior of the drying furnace.

[0008] Optionally, the burner's nozzle is connected to the lower part of the drying oven.

[0009] Optionally, there are multiple burners, which are arranged separately on opposite sides of the drying oven.

[0010] Optionally, it also includes a first temperature sensor, which, when detecting that the temperature inside the drying oven is lower than a first set value, controls the burner to increase the flame output via an electrical connection; and controls the burner to decrease the flame output via an electrical connection when the temperature is higher than a second set value.

[0011] Optionally, the burner has a first pneumatic shut-off valve and a second pneumatic shut-off valve connected in series; when the gas pressure in the burner is lower than 1000Pa, or when the burner nozzle does not emit flame, the first pneumatic shut-off valve and the second pneumatic shut-off valve simultaneously cut off the gas supply.

[0012] Optionally, the drying oven is also connected to a dust removal device, and a cold air valve is provided at the dust removal port connected to the dust removal device.

[0013] Optionally, a second temperature sensor is also included, which controls the cold air valve to close via electrical connection when the temperature of the dust removal port is lower than a third set value, and controls the cold air valve to open via electrical connection when the temperature is higher than a fourth set value.

[0014] Optionally, the burner nozzle is flat.

[0015] Optionally, the interior of the drying section is provided with a heat insulation layer made of high-strength castable.

[0016] Optionally, multiple guide plates are fixedly installed inside the drying furnace; along the height direction of the drying furnace, the multiple guide plates are arranged sequentially from top to bottom at intervals, with adjacent guide plates arranged alternately; each guide plate is inclined downwards, and the distance from the lower end of the guide plate to the inner wall of the drying furnace is greater than the diameter of the phosphate rock powder pellets; the guide plate is composed of multiple circular strips arranged at intervals; the burner nozzle sprays flames below the guide plates.

[0017] As described above, the phosphate rock powder pellet drying furnace with an internally connected burner of this utility model has at least the following beneficial effects:

[0018] This phosphate rock powder pellet drying furnace features a direct connection between the burner nozzle and the furnace interior. The phosphate rock powder pellets inside are directly baked by the flames emitted from the burner nozzle. Compared to indirect hot air baking, this method not only has lower energy costs but also quickly removes moisture from the surface of the phosphate rock powder pellets, forming a drier outer shell that prevents internal moisture from diffusing and eroding the pellet surface, ultimately producing higher quality phosphate rock powder pellets. Furthermore, because the flames directly emitted from the burner nozzles bake the phosphate rock powder pellets while simultaneously ablating the falling phosphate rock powder, this powder adheres to the pellets, reducing dust generation during production. Attached Figure Description

[0019] Figure 1 The image shown is a side view of a phosphate rock powder pellet drying furnace with an internally connected burner according to this utility model.

[0020] Figure 2 This is a front view of the present invention.

[0021] Figure 3 The image shown is a top view of this utility model.

[0022] Figure 4 The diagram shown is a schematic of the burner of this utility model.

[0023] Component designation explanation

[0024] Drying oven 1, feeding section 11, drying section 12, unloading section 13, burner 2, first pneumatic shut-off valve 21, second pneumatic shut-off valve 22, flame nozzle 23, guide plate 3, load-bearing beam 4, insulation layer 5. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0026] Please see Figures 1 to 4 It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and are not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0027] The following embodiments are for illustrative purposes only. These embodiments can be combined and are not limited to the content shown in any single embodiment below.

[0028] Please see Figure 1 and Figure 2 This utility model provides a phosphate rock powder pellet drying furnace 1 with an internally connected burner. Similar to the phosphate rock powder pellet drying device disclosed in Chinese Utility Model Patent No. CN215002793U in the background art, this phosphate rock powder pellet drying furnace 1 with an internally connected burner 2 is used to hold phosphate rock powder pellets. Heat energy is supplied to the interior through the burner 2 to dry the held phosphate rock powder pellets. The difference from the prior art is that the flame nozzle 23 of the burner 2 is directly connected to the interior of the drying furnace 1, and flames are sprayed into the interior of the drying furnace 1. Compared with indirect hot air baking, it not only has lower energy consumption and cost, but the direct baking of the flame can quickly remove the moisture on the surface of the phosphate rock powder pellets, thereby forming a relatively dry outer shell on the surface of the phosphate rock powder pellets, preventing the internal moisture of the phosphate rock powder pellets from diffusing outward and causing erosion on the surface of the pellets, and ultimately producing higher quality phosphate rock powder pellets.

[0029] In addition, because the flames directly ejected from the burner 2 nozzle 23 not only bake the phosphate rock powder pellets, they also directly ablate the falling phosphate rock powder, causing the phosphate rock powder to adhere to the phosphate rock powder pellets, thus reducing dust generated during production.

[0030] The Chinese utility model patent with authorization announcement number CN215002793U discloses a mineral powder pellet drying device that can produce 960 to 1200 tons of yellow phosphorus tail gas in the production of 200 tons of phosphate rock powder pellets, which means that 40 to 50 tons can be produced in one hour.

[0031] In another implementation, please refer to Figure 1 and Figure 2 Because the heat generated by combustion moves upward, the nozzle 23 of the burner 2 is connected to the lower part of the guide plate 3 of the drying oven 1, which further improves the energy utilization efficiency.

[0032] In another implementation, please refer to Figure 2 There are multiple burners 2, which are arranged separately on opposite sides of the drying furnace 1. Specifically, the design can be as follows: two burner nozzles 23 are arranged below the bottom guide plate 3 of the drying furnace 1, with these two nozzles 23 on one side; two burner nozzles 23 are arranged between the two bottom guide plates 3 of the drying furnace 1, with these two nozzles 23 on the other side; to ensure sufficient drying of phosphate rock powder pellets.

[0033] In another embodiment, as shown in the figure, the drying oven 1 is also connected to a dust removal device to further reduce the dust generated by the equipment. Since the burner 2 is arranged at the bottom of the drying oven 1, the dust removal device can be arranged at the top of the drying oven 1. This not only avoids interference between different components, but more importantly, since phosphate rock powder floats upward, the dust removal device arranged at the top of the drying oven 1 can better remove dust. At the same time, in order to avoid damage to the filter bags of the dust removal device by the high-temperature gas inside the drying oven 1, a cold air valve is installed at the dust removal port connected to the dust removal device.

[0034] In another implementation, please refer to Figure 4 The burner 2 has a first pneumatic shut-off valve 21 and a second pneumatic shut-off valve 22 connected in series. When the gas pressure inside the burner 2 is lower than 1000Pa, or when the nozzle 23 of the burner 2 does not emit flame, the first pneumatic shut-off valve 21 and the second pneumatic shut-off valve 22 simultaneously cut off the gas supply. Through the design of the two-stage pneumatic shut-off valves, the safety of the phosphate rock powder pellet drying furnace 1 with internal connection to the burner 2 is significantly improved.

[0035] In another embodiment, in order to accurately control the burner 2 and the cold air valve mentioned above, the phosphate rock powder pellet drying furnace 1 internally connected to the burner 2 further includes:

[0036] The first temperature sensor detects that when the temperature on the guide plate 3 is lower than the first set value, it controls the burner 2 to increase the flame through an electrical connection; when it is higher than the second set value, it controls the burner 2 to decrease the flame through an electrical connection; the first set value is less than the second set value, specifically, the first set value is 450°C and the second set value is 550°C.

[0037] The second temperature sensor detects that when the temperature of the dust removal port is lower than the third set value, it controls the cold air valve to close via electrical connection; when it is higher than the fourth set value, it controls the cold air valve to open via electrical connection; the third set value is less than the fourth set value, specifically, the third set value is 80℃ and the fourth set value is 120℃.

[0038] In another implementation, please refer to Figure 1 The burner 2 has a flat nozzle 23, which ensures that the flame is longer and can more easily dry the phosphate rock powder pellets in the space below the guide plate 3.

[0039] In another implementation, please refer to Figure 1 and Figure 2 The drying section 12 is equipped with a heat insulation layer 5 made of high-strength castable to effectively ensure the temperature inside the drying oven 1. High-strength castable is an unshaped refractory material with good fluidity and stability, which is made by adding a certain amount of binder to refractory materials and is constructed by casting. High-strength castable is usually composed of high-strength aggregate, powdered mineral additives and binders.

[0040] In another implementation, please refer to Figure 1 and Figure 2 The drying oven 1 has multiple guide plates 3 fixedly installed inside. Along the height direction of the drying oven 1, the multiple guide plates 3 are arranged sequentially from top to bottom at intervals, with adjacent guide plates 3 arranged alternately. For the specific form of the alternate arrangement, please refer to [link to relevant documentation]. Figure 1 Each of the guide plates 3 is inclined downwards, and the distance from the lower end of the guide plate 3 to the inner wall of the drying furnace 1 is greater than the diameter of the phosphate rock powder pellets, so as to ensure that the phosphate rock powder pellets fall smoothly from the upper guide plate 3 onto the lower guide plate 3. The guide plate 3 is composed of multiple round bars arranged at intervals. This design allows the hollow part in the middle of the guide plate 3 to have space for thermal expansion, and the falling phosphate rock powder can fall smoothly between the round bars. Compared with other hollow forms, the arrangement of multiple round bars at intervals makes it difficult for the falling phosphate rock powder to settle. Moreover, the staff can quickly make guide plates 3 of appropriate size according to the size of the drying furnace 1 by adjusting the number of round bars.

[0041] After the phosphate rock powder pellets and phosphate rock powder enter the drying furnace 1 from above, the phosphate rock powder pellets slide down along a downward inclined guide plate 3 onto another adjacent, staggered guide plate 3, until they leave the drying furnace 1 from below; at the same time, the phosphate rock powder falls down along the gap between the two round bars, and will not accumulate on the path of the phosphate rock powder pellets and cause blockage.

[0042] At the same time, the burner 2's nozzle 23 sprays flames below the guide plate 3, and the space below the guide plate 3 provides sufficient space for the combustion of phosphate rock powder pellets and phosphate rock powder; the phosphate rock powder pellets falling from one guide plate 3 to another guide plate 3 are directly baked by the flames sprayed from the burner 2's nozzle 23.

[0043] In another implementation, please refer to Figure 1 and Figure 2 The drying furnace 1 has a fixed load-bearing beam 4, which is an H-beam. The upper end of the guide plate 3 is fixed to the inner wall of the drying furnace 1. The fixed connection method can be welding or other methods, which will not be elaborated here. The lower part of the guide plate 3 overlaps the load-bearing beam 4. Generally, the lower surface of the lower part of the guide plate 3 overlaps the load-bearing beam 4. The advantage of this design is that the guide plate 3 is subject to thermal expansion and contraction. When the temperature inside the drying furnace 1 rises, even if the guide plate 3 expands due to heat, the lower part of the guide plate 3 overlaps the load-bearing beam 4. Therefore, the connection position of the guide plate 3 in this embodiment has space for thermal expansion. Compared with the method where both ends of the guide plate 3 are fixed, the probability of loosening of the guide plate 3 connection can be reduced, and the working reliability of the phosphate rock pellet drying furnace 1 with internal connection to the burner 2 can be improved.

[0044] In another implementation, please refer to Figure 1 The gap between the two round bars must achieve the following technical effect: phosphate rock powder pellets with a diameter greater than 5mm cannot fall through the gap, but slide down one guide plate 3 to the next guide plate 3, until they slide down to the feeding section 13. After being dried in the drying oven 1, the phosphate rock powder pellets that meet the requirements enter the next process, while those with smaller diameters that do not meet the requirements are sent back to the molding machine to ensure the full utilization of phosphate rock powder.

[0045] In other implementations, such as Figure 1 As shown, the drying oven 1 includes a feeding section 11, a drying section 12, and a discharging section 13 arranged sequentially from top to bottom.

[0046] The feed section 11 can be as follows: Figure 1 and Figure 2 The feeding hopper shown can also be the same as the feeding section described in the specification of Chinese Utility Model Patent No. CN215002793U, or other shapes.

[0047] The drying section 12 can be composed of multiple drying sections as shown in the figure. The multiple drying sections are connected by flanges. The guide plate 3 is set inside the drying section 12. The burner 2's nozzle 23 is connected to the interior of the drying section 12.

[0048] The feeding section 13 can also be the same as the feeding section described in the specification of Chinese Utility Model Patent No. CN215002793U. For the specific structure of the feeding section, please refer to paragraphs 0048-0052 of the specification of that utility model.

[0049] In summary, this invention, through the direct connection between the burner 2's nozzle 23 and the interior of the drying oven 1, allows the phosphate rock powder pellets inside the drying oven 1 to be directly baked by the flames emitted from the burner 2's nozzle 23. Compared to indirect hot air baking, this not only reduces energy consumption costs but also allows the direct flame baking to quickly remove moisture from the surface of the phosphate rock powder pellets, forming a relatively dry outer shell that prevents internal moisture from diffusing outwards and eroding the pellet surface, ultimately producing higher quality phosphate rock powder pellets. Furthermore, because the flames directly emitted from the burner 2's nozzle 23 are baking the phosphate rock powder pellets while simultaneously ablating the falling phosphate rock powder, this powder adheres to the pellets, reducing dust generation during production. Therefore, this invention effectively overcomes the shortcomings of existing technologies and has high industrial application value.

[0050] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A phosphate rock powder pellet drying furnace with an internally connected burner, used to hold phosphate rock powder pellets, and to dry the held phosphate rock powder pellets by supplying heat energy to the interior through the burner, characterized in that: The burner's nozzle is directly connected to the interior of the drying oven, and flames are directly injected into the drying oven. There are multiple burners, and the multiple burners are arranged separately on opposite sides of the drying oven; Multiple guide plates are fixedly installed inside the drying oven; along the height direction of the drying oven, the multiple guide plates are arranged at intervals from top to bottom, and two adjacent guide plates are arranged alternately.

2. The phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: The burner's nozzle is connected to the lower part of the drying oven.

3. The phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: It also includes a first temperature sensor, which, when detecting that the temperature inside the drying oven is lower than a first set value, controls the burner to increase the flame output via an electrical connection; and controls the burner to decrease the flame output via an electrical connection when the temperature is higher than a second set value.

4. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: The burner has a first pneumatic shut-off valve and a second pneumatic shut-off valve connected in series; When the gas pressure inside the burner is lower than 1000Pa, or when the burner nozzle does not emit flame, the first pneumatic shut-off valve and the second pneumatic shut-off valve simultaneously cut off the gas supply.

5. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: The drying oven is also connected to a dust removal device, and a cold air valve is installed at the dust removal port connected to the dust removal device.

6. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 5, characterized in that: It also includes a second temperature sensor, which controls the cold air valve to close via electrical connection when the temperature of the dust removal port is lower than a third set value, and controls the cold air valve to open via electrical connection when the temperature is higher than a fourth set value.

7. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: The burner nozzle is flat.

8. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: The drying oven includes a feeding section, a drying section and a discharging section arranged sequentially from top to bottom. The drying section is equipped with an insulation layer made of high-strength castable.

9. A phosphate rock powder pellet drying furnace with an internally connected burner according to claim 1, characterized in that: Each of the aforementioned guide plates is inclined downwards, and the distance from the lower end of the guide plate to the inner wall of the drying furnace is greater than the diameter of the phosphate rock powder pellets. The guide plate is composed of multiple circular strips arranged at intervals. The burner's nozzle sprays flames below the feed guide plate.

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