Compressed air supply system

Abstract

The utility model discloses a compressed air supply system belongs to chemical production technical field. Including air compressor, air compressor air tank, dehumidification device, filter press air tank and water station air tank, and the air inlet of air compressor air tank is connected with air compressor, the number of filter press air tank is multiple, and multiple filter press air tank is parallelly connected and its total capacity is 3 5 times of air compressor air tank capacity, the air outlet of air compressor air tank divides three ways output, the first road is connected with the import of dehumidification device, the second road is connected with the air inlet of filter press air tank, and the third road is connected with the air inlet of water station air tank, the air outlet of filter press air tank is connected with product two wash filter press, and the air outlet of water station air tank is connected with water treatment filter press, and the export of dehumidification device divides two ways output, one road is connected with the other gas equipment except water treatment filter press of water treatment workshop, and the other road is connected with the other gas equipment except product two wash filter press of product workshop.

Description

Technical Field

[0001] This utility model belongs to the field of chemical production technology, and specifically relates to a compressed air supply system, particularly to a compressed air supply system for the production of ferric phosphate that requires pressure filtration and water treatment processes. Background Technology

[0002] Lithium iron phosphate (LFP) is one of the most important cathode materials for lithium-ion batteries in the current lithium battery industry. Its characteristics include high discharge capacity, excellent cycle performance, low price, non-toxicity, and no environmental pollution. Currently, the mainstream production process for LFP uses anhydrous iron phosphate. In the preparation of anhydrous iron phosphate, an iron phosphate slurry is first synthesized, then filtered using a filter press to obtain an iron phosphate filter cake, which is then washed with pure water. The iron phosphate filter cake is typically washed directly with external pure water, and the resulting wash water is directly discharged to a wastewater treatment plant.

[0003] For example, patent application number CN202220146656.4 discloses a tiered washing system for ferric phosphate filter cake, including a filter press, a feeding unit, a mother liquor unit, a pure water unit, a washing water tank unit, and a washing water discharge unit. The feeding unit includes a feeding pipe, one end of which is connected to the feed inlet of the filter press. The mother liquor unit includes a mother liquor discharge pipe, which is connected to the outlet of the filter press. The pure water unit includes a pure water pipe, one end of which is connected to the inlet of the filter press. One end of the washing water tank unit is connected to the inlet of the filter press, and the other end of the washing water tank unit is connected to the outlet of the filter press. The washing water tank unit includes multiple washing water tank sub-units connected in parallel.

[0004] The production of lithium iron phosphate (LFP) involves a large amount of compressed air, including during LFP production, LFP washing, and water treatment. During LFP production, the compressed air is primarily used for pneumatic conveying and instrumentation. During LFP washing, it is mainly used for filter press purging (after filtration, purging further removes moisture). During water treatment, the compressed air is primarily used for filter press purging (after filtration, purging further removes moisture) and instrumentation.

[0005] Existing compressed air supply systems such as Figure 1As shown, the compressed air supply system includes an air compressor, an air compressor receiver tank, a dehumidifier, a filter press receiver tank, and a water station receiver tank. The number of filter press receiver tanks is one, with a capacity approximately the same as the air compressor receiver tank. The volume of the water station receiver tank is 1 / 3 to 2 / 3 of the air compressor receiver tank's volume. The air compressor, air compressor receiver tank, and dehumidifier are connected sequentially via pipelines. The dehumidifier has four outputs: the first connects to the inlet of the filter press receiver tank via a pipeline; the second connects to other air-using equipment in the product workshop, excluding the secondary washing filter press; the third connects to the inlet of the water station receiver tank via a pipeline; and the fourth connects to the water treatment filter press. The outlet of the filter press receiver tank is connected to the secondary washing filter press via a pipeline, and the outlet of the water station receiver tank is connected to other air-using equipment in the water treatment workshop, excluding the water treatment filter press.

[0006] The existing system works as follows: the filter press is manually purged on-site during the second washing process. During the purging process, the compressed air inlet valve can only be opened 1 / 3. Under the condition that the control indicators of the previous process remain unchanged, the solid content of the filter cake (measured after drying at 650℃ for 2 hours) can only reach about 39%. When the inlet valve is fully opened, the solid content of the filter cake can reach about 40%, which can improve the solid content by 1 percentage point. However, when the inlet valve is fully opened, the compressed air supply from the air compressor station is insufficient, resulting in a large drop in the pressure of the main compressed air network, which affects the normal operation of other air-using equipment in the workshop.

[0007] The applicant encountered the following problems when using the existing compressed air supply system: (1) The gas used by the filter press and the gas used by the non-filter press (mainly valves and instruments) are not distinguished, the gas consumption is large, the load on the refrigerated dryer is large and the gas drying effect is poor; (2) The compressed air buffer space of the filter press storage tank is too small. When the large volume is purged, the system air pressure drops too much, affecting the normal operation of the compressed air system. When the small volume is used to purge the filter cake of the second washing, the moisture content is too high, resulting in high natural gas energy consumption during subsequent drying. Utility Model Content

[0008] To address the aforementioned problems, this utility model provides a compressed air supply system that improves upon existing systems by increasing the number of air tanks for the filter press and adjusting their connections. This reduces the load on the refrigerated dryer, increases the air supply to the second-wash filter press, reduces overall system pressure fluctuations, lowers the water content of the product, and thus reduces energy consumption. The technical solution is as follows: This utility model provides a compressed air supply system, which includes an air compressor, an air compressor storage tank, a dehumidifier, a filter press storage tank, and a water station storage tank. The air inlet of the air compressor storage tank is connected to the air compressor via a pipeline. The system is characterized by having multiple filter press storage tanks connected in parallel, with a total capacity 3-5 times that of the air compressor storage tank. The air outlet of the air compressor storage tank has three outputs: the first output is connected to the inlet of the dehumidifier via a pipeline; the second output is connected to the third output; the third output is connected to the fourth output; the third output is connected to the fifth output; the third output is connected to the fifth output; the fourth output is connected to the fifth output; the fifth output is connected to the sixth output; the third output is connected to the fifth output; the fifth output is connected to the sixth output; the sixth output is connected to the seventh output; the seventh output is connected to the fifth output; the fifth output is connected to the sixth output; the sixth output is connected to the seventh output; the seventh output is connected to the fifth output; the sixth output is connected to the seventh output; the seventh output is connected to the fifth output; the seventh output is connected to the seventh output; the eighth output is connected to the fifth output; the ninth output is connected to the seventh ... eleventh output is connected to the eleventh output; the eleventh output is connected to the eleventh output; the eleventh output is connected to the eleventh output; the eleventh output is connected to the eleventh output; the eleventh output is connected to the eleventh output; the eleventh output is connected to the eleven The second airway is connected to the air inlet of the filter press's air storage tank via a pipeline, and the third airway is connected to the air inlet of the water station's air storage tank via a pipeline. The air outlet of the filter press's air storage tank is connected to the product's second washing filter press via a pipeline, and the air outlet of the water station's air storage tank is connected to the water treatment filter press via a pipeline. The dehumidification device has two outputs: one is connected to other air-using equipment in the water treatment workshop (excluding the water treatment filter press) via a pipeline, and the other is connected to other air-using equipment in the product workshop (excluding the product's second washing filter press) via a pipeline.

[0009] In this embodiment of the invention, the volume of the water station air storage tank is 1 / 3 to 2 / 3 of the volume of the air compressor air storage tank.

[0010] Specifically, in this embodiment of the invention, there are multiple air compressors connected in parallel, and their total air production is 70-80m³. 3 / min; the volume of the air compressor's air tank is 10m³. 3 The volume of the gas storage tank at the water station is 5m³. 3 The filter press has three air storage tanks, each with a volume of 20m³. 3 20m 3 and 10m 3 .

[0011] Specifically, in this embodiment of the invention, the air inlet of the filter press air tank has a pipe diameter of 38mm, which is connected to a main pipe with a pipe diameter of 108mm via an air inlet branch pipe with a pipe diameter of 38mm; the main pipe is connected to each product secondary washing filter press via an air outlet branch pipe with a pipe diameter of 57mm.

[0012] The dehumidification device in this embodiment of the invention includes a refrigerated dryer and an adsorption dryer connected in sequence by pipelines. The beneficial effects of the technical solution provided by this utility model embodiment are as follows: This utility model embodiment provides a compressed air supply system, which improves the existing system by increasing the number of air storage tanks for the filter press and adjusting the connection relationship, reducing the burden on the refrigerated dryer, providing air supply to the filter press for the second washing of the product, reducing the overall system pressure fluctuation (the pressure of the main compressed air network after the modification is reduced from 0.7MPa to 0.55MPa, which will not affect the operation of other equipment), reducing the water content of the product (free water is reduced by 6%), and thus reducing the energy consumption of subsequent drying. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of an existing compressed air supply system. Figure 2 This is a schematic diagram of the compressed air supply system provided in this embodiment of the utility model. Detailed Implementation

[0014] 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.

[0015] Example 1 See Figure 2 Example 1 provides a compressed air supply system, which includes an air compressor, an air compressor storage tank, a dehumidifier, a filter press storage tank, and a water station storage tank. The air inlet of the air compressor storage tank is connected to the air compressor via a pipeline. The dehumidifier includes a refrigerated dryer and an adsorption dryer connected sequentially via pipelines. There are multiple filter press storage tanks (specifically 2-4), arranged in parallel, with a total capacity 3-5 times that of the air compressor storage tank. The volume of the water station storage tank is 1 / 3-2 / 3 of the volume of the air compressor storage tank. The air compressor storage tank, filter press storage tank, and water station storage tank are made of CS+polyurea.

[0016] The air compressor's air tank has three outlets: the first connects to the inlet of the dehumidification device via a pipeline; the second connects to the inlet of the filter press's air tank via a pipeline; and the third connects to the inlet of the water station's air tank via a pipeline. The filter press's air tank outlet connects to multiple product washing filter presses via pipelines, and the water station's air tank outlet connects to multiple water treatment filter presses via pipelines. The dehumidification device has two outlets: one connects to other air-using equipment (including valves and aerators) in the water treatment workshop (used for treating mother liquor, washing liquid, equipment flushing water, and other water), excluding the water treatment filter press; the other connects to other air-using equipment (including valves, pneumatic conveyors, ball mills, etc.) in the product workshop (including synthesis, filtration, washing, drying, and pulverizing processes), excluding the product washing filter press.

[0017] Example 2 See Figure 2 Example 2 provides a compressed air supply system, the structure of which is basically the same as that of Example 1, except that: in this example, there are multiple air compressors connected in parallel, and their total air production is 70-80m³. 3 / min. The air compressor's air receiver tank has a volume of 10m³. 3 The water station's gas storage tank has a volume of 5m³. 3The filter press has three air storage tanks, each with a volume of 20m³. 3 20m 3 and 10m 3 Specifically, the air inlet of the filter press's air storage tank has a diameter of 38mm, which is connected to a main pipe with a diameter of 108mm via a 38mm inlet branch pipe. The main pipe is connected to each product's secondary washing filter press via a 57mm outlet branch pipe (equipped with a pneumatic regulating valve for easy control). The inlet branch pipe, main pipe, and outlet branch pipe are all made of 304 stainless steel.

[0018] Example 3 Example 3 provides a compressed air supply system, the structure of which is basically the same as that of Example 2, except that: this example has three air compressors, each with an air production capacity of 24m³. 3 / min, 30m 3 / min and 30m 3 / min. The number of product washing filter presses is 5, and the number of water treatment filter presses is 5.

[0019] Example 4 Example 4 provides a method for using a compressed air supply system. After the improvement, the purging method of the second washing filter press adopts forward blowing without changing the original process flow. After the air intake adopts a pneumatic regulating valve, the initial air intake valve opening is 5-10%. Purge for 3-5 minutes to blow away the water in the exhaust pipe, and then fully open the valve to avoid water hammer forming in the exhaust pipe and damaging the pipe.

[0020] This patent has the following advantages: (1) The purging air of the second washing filter press is moved to the front of the refrigerated dryer to reduce the operating load of the refrigerated dryer.

[0021] (2) Before the modification, the pressure of the main compressed air network dropped from 0.7MPa to 0.4MPa during purging. After the modification, the pressure of the main compressed air network dropped from 0.7MPa to 0.55MPa, which did not affect the normal operation of other air-using equipment in the workshop.

[0022] (3) The free water content in the filter cake after the second washing was 2900kg-3500kg before the modification and was reduced to 2700kg-3200kg after the modification, with a 6% reduction in free water. The current dewatering equipment consists of a hot air furnace (for removing free water) and a rotary kiln (for removing crystallization water). When operating separately, the gas consumption is the same. When operating simultaneously, the hot air furnace has heat that can be reused. Compared with before the modification, the natural gas consumption can be reduced by about 5.5%.

[0023] (4) Reduce material blockage in the conveying screw caused by excessive moisture in the filter cake, and reduce the labor intensity of employees.

[0024] In this embodiment, "first", "second", "third" and "fourth" serve only as distinctions and have no other special meanings.

[0025] 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 compressed air supply system, comprising an air compressor, an air compressor receiver tank, a dehumidifier, a filter press receiver tank, and a water station receiver tank, wherein the air inlet of the air compressor receiver tank is connected to the air compressor via a pipeline; characterized in that, The filter press air storage tanks are multiple, connected in parallel, with a total capacity 3-5 times that of the air compressor air storage tanks. The air compressor air storage tanks have three outlets: the first connects to the inlet of the dehumidification device via a pipeline, the second connects to the inlet of the filter press air storage tank via a pipeline, and the third connects to the inlet of the water station air storage tank via a pipeline. The outlets of the filter press air storage tanks are connected to the product secondary washing filter press via pipelines, and the outlets of the water station air storage tanks are connected to the water treatment filter press via pipelines. The dehumidification device has two outlets: one connects to the air-using equipment in the water treatment workshop (excluding the water treatment filter press) via a pipeline, and the other connects to the air-using equipment in the product workshop (excluding the product secondary washing filter press) via a pipeline.

2. The compressed air supply system according to claim 1, characterized in that, The volume of the water station's air storage tank is 1 / 3 to 2 / 3 of the volume of the air compressor's air storage tank.

3. The compressed air supply system according to claim 1, characterized in that, There are multiple air compressors connected in parallel, and their total air production is 70-80m³. 3 / min; the volume of the air compressor's air tank is 10m³. 3 The volume of the gas storage tank at the water station is 5m³. 3 The filter press has three air storage tanks, each with a volume of 20m³. 3 20m 3 and 10m 3 .

4. The compressed air supply system according to claim 3, characterized in that, The air inlet of the filter press's air storage tank has a diameter of 38mm, which is connected to a main pipe with a diameter of 108mm via an air inlet branch pipe with a diameter of 38mm; the main pipe is connected to each product's secondary washing filter press via an air outlet branch pipe with a diameter of 57mm.

5. The compressed air supply system according to claim 1, characterized in that, The dehumidification device includes a refrigerated dryer and an adsorption dryer connected in sequence by pipelines.

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