Closed filtering device for alkali production

Abstract

The utility model discloses a closed filtering device for alkali production, which comprises a device body, a main filtering cavity and two auxiliary filtering cavities are arranged in the device body, and the two auxiliary filtering cavities are respectively communicated with the main filtering cavity; the main filtering cavity comprises a feeding cavity at the upper end and a first negative pressure cavity at the lower end, a feeding opening is formed in the upper end face of the feeding cavity, and a main filtering net is arranged at the bottom end of the feeding cavity and is separated from the first negative pressure cavity; the auxiliary filter cavity comprises a filter residue temporary storage cavity at the upper end and a second negative pressure cavity at the lower end, a valve port is formed in the side wall of the filter residue temporary storage cavity and communicated with the feeding cavity, and an auxiliary filter screen is arranged at the bottom end of the filter residue temporary storage cavity and separated from the second negative pressure cavity. According to the utility model, the problems that a large amount of ammonia gas is discharged when a traditional open type filtering device is applied to an alkali production process and a closed type filtering device affects the production efficiency are solved.

Description

Technical Field

[0001] This utility model relates to the field of alkali production equipment technology, and in particular to a closed-loop filtration device for alkali production. Background Technology

[0002] The ammonia-soda process is a common industrial method for producing soda ash. After the carbonation process, the NaHCO3 crystals in the solution need to be filtered and separated before being calcined to obtain the soda ash product. However, the solution output from the carbonation tower to the filtration device still carries a large amount of ammonia. If a traditional open filtration device is used, a large amount of ammonia will be emitted into the atmosphere, causing environmental pollution. If a closed filtration device is used, the crystals need to be collected and treated periodically, making continuous filtration production impossible and affecting production efficiency. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a closed filtration device for alkali production, which solves the problems of large-scale ammonia emission when traditional open filtration devices are used in the alkali production process, while closed filtration devices affect production efficiency.

[0004] Technical Solution: To achieve the above objectives, this utility model provides a closed-loop filtration device for alkali production, comprising a device body. The device body contains a main filtration chamber and two auxiliary filtration chambers, each connected to the main filtration chamber. The main filtration chamber includes an upper feed chamber and a lower first negative pressure chamber. The upper surface of the feed chamber has a feed inlet, and the bottom of the feed chamber is equipped with a main filter screen, separating it from the first negative pressure chamber. The auxiliary filtration chamber includes an upper filter residue storage chamber and a lower second negative pressure chamber. The side wall of the filter residue storage chamber has a valve port connected to the feed chamber, and the bottom of the filter residue storage chamber is equipped with an auxiliary filter screen, separating it from the second negative pressure chamber.

[0005] Furthermore, the feeding chamber is equipped with a liquid level sensing module, and the sensing signal output terminal of the liquid level sensing module is electrically connected to the opening and closing control module of the two valve ports.

[0006] Furthermore, the main filter screen has a curved surface structure that is high in the middle and low on both sides, the feed inlet is located in the middle of the main filter screen, and the two valve ports are respectively located on the two low sides of the main filter screen.

[0007] Furthermore, the secondary filter screen is located below the valve port, and the secondary filter screen is inclined, with its end near the valve port being the high end. The filter residue temporary storage chamber is provided with a slag discharge port near the low end of the secondary filter screen.

[0008] Furthermore, the secondary filter chamber is equipped with a pressure sensor, and the signal output terminal of the pressure sensor is electrically connected to the extraction module corresponding to the second negative pressure chamber.

[0009] Furthermore, the secondary filter chamber is equipped with a gas concentration sensor, and the signal output terminal of the gas concentration sensor is electrically connected to the opening and closing control module corresponding to the slag discharge port.

[0010] Beneficial Effects: This utility model discloses a closed-loop filtration device for alkali production. Through the alternating connection of the main filtration chamber and two auxiliary filtration chambers, it ensures synchronous and continuous filtration of filtration and residue collection, effectively guaranteeing the production efficiency of alkali products. Furthermore, both the main and auxiliary filtration chambers are equipped with independent negative pressure chambers, enabling independent solid-liquid separation. The device also minimizes the ammonia content within the chambers through suction, effectively reducing the amount of ammonia emitted into the atmosphere when the chambers are opened to collect the residue, thus avoiding environmental pollution. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structural framework of one embodiment of the present invention. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings.

[0013] As attached Figure 1 A closed-loop filtration device for alkali production includes a device body, which contains a main filtration chamber and two auxiliary filtration chambers, each connected to the main filtration chamber. The main filtration chamber includes an upper feed chamber 1 and a lower first negative pressure chamber 2. The upper surface of the feed chamber 1 has a feed inlet 11, and the bottom of the feed chamber 1 is provided with a main filter screen 3, which separates it from the first negative pressure chamber 2. The auxiliary filtration chamber includes an upper filter residue storage chamber 4 and a lower second negative pressure chamber 5. The side wall of the filter residue storage chamber 4 has a valve port 41, which communicates with the feed chamber 1. The bottom of the filter residue storage chamber 4 is provided with an auxiliary filter screen 6, which separates it from the second negative pressure chamber 5.

[0014] This scheme sequentially delivers the solution output from the carbonization tower to the main filtration chamber and the secondary filtration chamber to achieve solid-liquid separation. By controlling the connecting valve, the main filtration chamber is connected to only one secondary filtration chamber, while the other secondary filtration chamber can be used as a separate, independent chamber for crystal collection. This does not affect the normal filtration process. By controlling the alternating opening and closing of the valve, the main and secondary filtration chambers can be connected alternately, ensuring synchronous and continuous filtration and effectively guaranteeing the production efficiency of alkali products. Both the main and secondary filtration chambers are equipped with independent negative pressure chambers for extracting filtrate and ammonia through the filter screen. This allows NaHCO3 crystals to remain on the filter screen surface, achieving solid-liquid separation. Furthermore, the secondary filtration chamber, separated from the main filtration chamber, can be used for rinsing and cleaning the crystals, as well as for re-drying. The ammonia content in the chamber is also reduced as much as possible through suction, effectively minimizing ammonia emissions into the atmosphere when the chamber is opened to collect filter residue, thus avoiding environmental pollution.

[0015] The feed chamber 1 is equipped with a liquid level sensing module, and the sensing signal output terminal of the liquid level sensing module is electrically connected to the opening and closing control module of the two valve ports 41. Before the liquid level in the feed chamber reaches the specified liquid level height, both valve ports can be closed, and vacuum filtration is performed by the first negative pressure chamber of the main filtration chamber. After reaching the specified liquid level, one valve port is opened, allowing the solution to flow into the one-sided auxiliary filtration chamber and flush the crystals on the surface of the main filter screen into the auxiliary filtration chamber. At the same time, the second negative pressure chamber of the connected auxiliary filtration chamber starts working to further filter the solution entering the auxiliary filtration chamber. The valve port is opened for a period of time and then closed. If the liquid level in the feed chamber is lower than the specified liquid level at this time, the valve port remains closed until the specified liquid level is reached, and then the opposite valve port is opened. If the liquid level reaches the specified liquid level, the opposite valve port is opened directly, so that the other auxiliary filtration chamber is connected to the main filtration chamber. During this process, the previously connected secondary filter chamber continues to work, sequentially completing filtration, cleaning, drying, and evacuation. After ensuring stable chamber pressure and that the ammonia content meets the standard, the chamber is opened to discharge the dried NaHCO3 crystals. The two secondary filter chambers alternately discharge the dried NaHCO3 crystal products, thereby maximizing production efficiency.

[0016] The main filter screen 3 has a curved surface structure that is higher in the middle and lower on both sides. The feed inlet 11 is located in the middle of the main filter screen 3, and the two valve ports 41 are respectively located on the two lower sides of the main filter screen 3. The curved surface structure helps to increase the filter screen area and improve the filtration efficiency. At the same time, under the flushing of the feed from above, it prevents crystals from adhering to the filter screen surface and causing blockage, and facilitates the flow of crystals to the secondary filter chambers on both sides.

[0017] The secondary filter screen 6 is located below the valve port 41. The secondary filter screen 6 is inclined, with its end near the valve port 41 being the high end. The filter cake storage chamber 4 is provided with a discharge port 42 near the low end of the secondary filter screen 6. The inclined arrangement of the secondary filter screen also helps to increase the filtration area and facilitates the discharge of the final filter cake. A scraper can be provided on the surface of the filter screen to reduce the residue of crystals on the filter screen surface and avoid affecting the subsequent filtration effect.

[0018] The secondary filter chamber is equipped with a pressure sensor, and the signal output terminal of the pressure sensor is electrically connected to the extraction module corresponding to the second negative pressure chamber 5. Based on the monitoring of the pressure within the chamber, the operating power of the corresponding negative pressure chamber can be controlled to ensure pressure stability within the chamber, especially ensuring pressure stability when the chamber is open, thus preventing safety accidents.

[0019] The secondary filter chamber is equipped with a gas concentration sensor, the signal output of which is electrically connected to the opening / closing control module corresponding to the slag discharge port 42. The gas concentration sensor is used to detect the ammonia content in the chamber. Only after ensuring that the ammonia concentration in the chamber is below a certain value will the corresponding slag discharge port be opened to collect the NaHCO3 crystallization product, thus strictly controlling the leakage of ammonia.

[0020] Both the first and second negative pressure chambers have extraction ports 7 on one side wall for connecting to a vacuum pump. The top of each secondary filter chamber has an air inlet 43, which, after being isolated from the main filter chamber, allows air to be drawn into the chamber to balance the internal pressure.

[0021] The above are merely preferred embodiments of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A closed filter device for the production of caustic soda, characterized in that: The device comprises a device body, a main filter cavity and a secondary filter cavity are arranged in the device body, and the two secondary filter cavities are communicated with the main filter cavity respectively; the main filter cavity comprises a feeding cavity (1) at the upper end and a first negative pressure cavity (2) at the lower end, a feeding port (11) is arranged on the upper end surface of the feeding cavity (1), and a main filter screen (3) is arranged at the bottom end of the feeding cavity (1) and separates the first negative pressure cavity (2); the secondary filter cavity comprises a filter residue temporary storage cavity (4) at the upper end and a second negative pressure cavity (5) at the lower end, a valve port (41) is arranged on the side wall of the filter residue temporary storage cavity (4) and is communicated with the feeding cavity (1), and a secondary filter screen (6) is arranged at the bottom end of the filter residue temporary storage cavity (4) and separates the second negative pressure cavity (5).

2. A filtering device for closed-circuit caustic soda production according to claim 1, characterized in that: The feeding cavity (1) is provided with a liquid level sensing module, and an inductive signal output end of the liquid level sensing module is electrically connected to an opening and closing control module of the two valve ports (41).

3. A filtering device for closed-circuit caustic soda production according to claim 2, characterized in that: The main filter screen (3) is a curved surface structure with high middle and low sides, the feeding port (11) is arranged opposite to the main filter screen (3), and the two valve ports (41) are arranged corresponding to the two low sides of the main filter screen (3).

4. A filtering device for closed-circuit caustic soda production according to claim 3, characterized in that: The secondary filter screen (6) is located below the valve port (41), the secondary filter screen (6) is arranged obliquely, one end close to the valve port (41) is a high end, and a residue discharge port (42) is arranged close to the low end of the secondary filter screen (6) on the filter residue temporary storage cavity (4).

5. A filtering device for closed-circuit caustic soda production according to claim 4, characterized in that: The secondary filter cavity is provided with a pressure sensor, and a signal output end of the pressure sensor is electrically connected to an extraction module corresponding to the second negative pressure cavity (5).

6. A filtering device for the production of caustic soda according to claim 5, characterized in that: The secondary filter cavity is provided with a gas concentration sensor, and a signal output end of the gas concentration sensor is electrically connected to an opening and closing control module corresponding to the residue discharge port (42).

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