A method and system for dosing industrial wet salt particles

Abstract

The present application relates to chlor-alkali chemical technology field, specifically to a kind of industrial wet salt particle quantitative feeding method and system.The present application takes industrial wet salt as object, and the way of weighing measurement is used to prepare sodium chloride particle suspension, improve the transportability of wet sodium chloride salt particle, simultaneously through gravity concentration preparation solid-liquid ratio stable sodium chloride particle slurry, then the quantitative feeding required by salting-out is completed by volumetric flow metering method.The method provided by the present application is simple, breaks through the technical limitation that current salting-out method can only use industrial dry salt, uses economic way to complete the high-precision delivery of industrial wet salt, improves the economic benefit of the technology of removing sulphate in brine system by salting-out method.

Description

Technical Field

[0001] This invention relates to the field of chlor-alkali chemical technology, and in particular to a method and system for quantitatively adding industrial wet salt particles. Background Technology

[0002] In existing methods for removing sulfate ions from brine systems in chlor-alkali plants, salting-out is involved. This method involves adding sodium chloride granules, which dissolve, increasing the concentration of soluble sodium chloride in the solution. This, in turn, reduces the saturated solubility of sodium sulfate, leading to the precipitation of sodium sulfate. While most technical experts and workers in this field focus on the overall balance of the salting-out system and the optimization of salting-out crystallization techniques, little attention has been paid to the addition of sodium chloride granules.

[0003] According to the national standard GB / T5462, industrial salt can be divided into refined salt and sun-dried salt based on differences in its physicochemical properties. In the production technology of sodium sulfate (Glauber's salt), refined salt is essential to reduce the impact of impurities on the production system. Similarly, according to the national standard, refined salt can be further divided into industrial dry salt and industrial wet salt. The significant difference between the two lies in their moisture content. Industrial wet salt has a higher moisture content, which leads to completely different transport characteristics compared to industrial dry salt. For example, its static angle of repose can reach over 70°, and even its compressive angle of repose can reach over 90°. Industrial dry salt, on the other hand, has a static angle of repose of less than 45°, and its apparent density does not differ significantly under pressure. In terms of storage characteristics, industrial wet salt stored for more than 10 days develops a hard shell on its surface due to capillary dehydration and natural evaporation, reducing its fluidity. Over time, compressed industrial wet salt may even clump together, requiring extremely strong external force to break. This process is much slower for industrial dry salt.

[0004] These significant differences limit the application of industrial wet salt. In the field of sulfate removal from brine systems, the salt dosage needs to be precisely measured. Insufficient salt will prevent the salting-out endpoint from being reached; excessive salt will result in salt particles in the final sodium sulfate product, leading to excessive chloride levels in the byproduct. If methods such as pneumatic or vacuum conveying are used, uneven material distribution at the inlet will result in uneven metering at the outlet. Due to these factors, there is no practical experience in using industrial wet salt as a salting-out agent in industrial production and related technologies. Production technologies all use industrial dry salt as the salting-out agent.

[0005] As is well known, industrial dry salt is produced by drying and dehydrating industrial wet salt. Therefore, in the salt supply market, industrial dry salt has a higher price than industrial wet salt, with a price difference of more than 20%. Using industrial dry salt to meet the needs of sulfate removal in brine systems inevitably increases the raw material costs for enterprises. Summary of the Invention

[0006] In view of the above situation and to overcome the shortcomings of the existing technology, the present invention provides a method and system for quantitative addition of industrial wet salt particles.

[0007] The technical solution to the problem solved by this invention is as follows:

[0008] To address the engineering challenges of adding industrial wet salt particles, this invention fully utilizes the transport characteristics of high-concentration suspensions and combines gravity sedimentation concentration and pipeline metering with other engineering methods to complete the addition of industrial wet salt particles. This truly solves the problem of industrial wet salt being unusable in salting-out systems, while also reducing the energy consumption of the salting-out system and optimizing the production process.

[0009] To achieve the above and other related objectives, the first aspect of the present invention provides a method for quantitatively adding industrial wet salt particles, comprising the following steps:

[0010] S1. Weigh the industrial wet salt and add it to the wet salt processing unit to obtain a high concentration of sodium chloride suspension.

[0011] S2. The high-concentration sodium chloride suspension is transported to a gravity concentration unit at a high position to obtain a clear saturated sodium chloride solution and a granular slurry with stable solid content.

[0012] S3. The granular slurry flows into the dosing pipeline from a high position by gravity, and is then sent to the dosing point required for the salting-out process through the quantitative dosing unit on the dosing pipeline, so as to achieve precise dosing of sodium chloride.

[0013] S4. Send the clear saturated sodium chloride solution into the reflux device and reuse it in the wet salt unit.

[0014] In some embodiments of the present invention, the moisture content of the industrial wet salt is 0.8 wt% to 4 wt%.

[0015] In some embodiments of the present invention, the sodium chloride particle settling ratio of the high-concentration suspension is 25% to 40%.

[0016] In some embodiments of the present invention, the residence time of the gravity concentration unit is greater than 15 minutes.

[0017] In some embodiments of the present invention, the mass percentage of sodium chloride particles in the granular slurry is 62% ± 3%.

[0018] In some embodiments of the present invention, the height difference between the top liquid level of the gravity concentration unit and the addition point required for the salting-out process is more than 12m; and / or, the quantitative addition unit uses a pipeline fluid metering method for quantitative addition.

[0019] A second aspect of the present invention provides a quantitative dosing system for industrial wet salt particles, comprising a wet salt dissolving unit, a conveying unit, a gravity concentration unit, and a quantitative dosing unit;

[0020] The wet salt preparation unit is equipped with an industrial wet salt inlet, a makeup water inlet, and a high-concentration sodium chloride suspension outlet, and is used to prepare a high-concentration sodium chloride suspension.

[0021] The conveying unit includes a conveying pump and a conveying pipeline connected to the outlet of the conveying pump, used to stably convey a high-concentration sodium chloride suspension to a gravity concentration unit at a high level; the suction pipe of the conveying pump is connected to the outlet of the high-concentration sodium chloride suspension of the wet salt unit.

[0022] The gravity concentration unit is equipped with a high-concentration sodium chloride suspension inlet, a clarified saturated sodium chloride solution outlet, and a granular slurry outlet, used to gravity concentrate the high-concentration sodium chloride suspension to obtain a granular slurry with a stable solid-liquid ratio; the high-concentration sodium chloride suspension inlet is connected to the conveying pipeline of the conveying unit.

[0023] The quantitative dosing unit is located on the pipeline connecting the particle slurry outlet of the gravity concentration unit and the dosing point required for the salting-out process, and is used to achieve stable sodium chloride dosing.

[0024] In some embodiments of the present invention, the system further includes a feeding unit for adding industrial wet salt to the industrial wet salt inlet of the wet salt processing unit.

[0025] In some embodiments of the present invention, the dehumidification salt unit further includes a detection bypass and a suspension concentration detection device, which facilitates sampling and detection of the concentration of high-concentration sodium chloride suspension.

[0026] In some embodiments of the present invention, the gravity concentration unit is provided with a stirring device.

[0027] In some embodiments of the present invention, the height difference between the top liquid level of the gravity concentration unit and the addition point required for the salting-out process is more than 12m.

[0028] In some embodiments of the present invention, the system further includes a reflux device with a clarified saturated sodium chloride solution inlet and a reflux liquid outlet, for reusing the clarified saturated sodium chloride solution in the wet salt preparation unit; the clarified saturated sodium chloride solution inlet is connected to the clarified saturated sodium chloride solution outlet of the gravity concentration unit, and the reflux liquid outlet is connected to the reflux liquid inlet of the wet salt preparation unit.

[0029] In some embodiments of the present invention, the quantitative dosing unit includes a dosing adjustment device and a dosing metering device. The dosing adjustment device is used to adjust the flow rate of the granular slurry, and the dosing metering device is used to accurately measure the amount of granular slurry added.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention provides a precise dosing device and method for industrial wet salt particles, which uses industrial wet salt as the precise dosing target. It prepares a suspension containing sodium chloride particles by weighing and metering, which improves the transportability of wet sodium chloride particles. At the same time, it produces a sodium chloride particle slurry with a stable solid-liquid ratio by gravity concentration, and then completes the quantitative dosing required for salting out by volume flow metering. This achieves precise quantitative dosing of industrial wet salt, so that the salting out process does not need to use industrial dry salt, which improves the applicability of salting out technology, saves on the consumption level of salting out technology, and achieves good economic benefits.

[0032] 2. The precise addition device and method for industrial wet salt particles provided by this invention breaks through the technical limitation that the current salting-out method can only use industrial dry salt. It achieves high-precision delivery of industrial wet salt in an economical way, with high metering accuracy and addition accuracy within ±1%. It can achieve the accuracy of weighing method in the process of adding industrial dry salt, and also has high reliability of delivery and adjustment. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention for a quantitative dosing system of industrial wet salt particles.

[0034] Figure 2 This is a schematic diagram of a quantitative dosing system for industrial wet salt particles according to another preferred embodiment of the present invention.

[0035] Reference numerals: 101-Feeding unit; 102-Wet salt unit; 103-Conveying unit; 104-Gravity concentration unit; 105-Quantitative dosing unit; 106-Reflux device; 107-Heat exchanger; 201-Suspension concentration detection device; 202-Dosing adjustment device; 203-Dosing metering device. Detailed Implementation

[0036] The following details the quantitative addition method and system for industrial wet salt granules of the present invention.

[0037] The first aspect of this invention provides a method for quantitatively adding industrial wet salt particles, comprising the following steps:

[0038] S1. Weigh the industrial wet salt and add it to the wet salt processing unit to obtain a high concentration of sodium chloride suspension.

[0039] S2. The high-concentration sodium chloride suspension is transported to a gravity concentration unit at a high position to obtain a clear saturated sodium chloride solution and a granular slurry with stable solid content.

[0040] S3. The granular slurry flows into the dosing pipeline from a high position by gravity, and is then sent to the dosing point required for the salting-out process through the quantitative dosing unit on the dosing pipeline, so as to achieve precise dosing of sodium chloride.

[0041] S4. Send the clear saturated sodium chloride solution into the reflux device and reuse it in the wet salt unit.

[0042] The precise dosing target of this invention is industrial wet salt. First, a wet salt treatment process is carried out to obtain a high-concentration sodium chloride suspension containing sodium chloride particles. The high-concentration sodium chloride suspension is then concentrated by gravity to obtain a sodium chloride particle slurry with a stable solid-liquid ratio (the mass percentage of sodium chloride particles in the slurry is 62% ± 3%). The slurry is then added to the wet salt treatment unit (conveying and regulating device and metering device) on the dosing pipeline to achieve stable sodium chloride addition, so as to complete the subsequent salting-out reaction. After solid-liquid concentration, the clarified saturated sodium chloride solution is returned to the wet salt treatment unit through a reflux device for recycling.

[0043] In some embodiments of the present invention, the moisture content of the industrial wet salt is 0.8wt% to 4wt%, and can be 0.8wt% to 1.2wt%, 1.2wt% to 1.6wt%, 1.6wt% to 2.0wt%, 2.0wt% to 2.4wt%, 2.4wt% to 2.8wt%, 2.8wt% to 3.2wt%, 3.2wt% to 3.6wt%, or 3.6wt% to 4wt%.

[0044] In some embodiments of the present invention, the sodium chloride particle settling ratio of the high-concentration sodium chloride suspension is 25%–40%, which can be 25%–30%, 30%–35%, or even 35%–40%. The high-concentration sodium chloride suspension mentioned in the present invention refers to a suspension mixture containing sodium chloride particles and a saturated sodium chloride solution, wherein the sodium chloride particles are in a suspended state under flowing conditions. The sodium chloride particle settling ratio refers to the percentage of the total volume of the high-concentration sodium chloride suspension after 1000 mL of the high-concentration sodium chloride suspension is placed in a 1000 mL graduated cylinder and allowed to stand for 10 minutes in a light-proof and vibration-proof location.

[0045] In some embodiments of the present invention, the residence time of the gravity concentration unit is greater than 15 min, and can be 15.1–15.5 min, 15.5–16 min, 16–16.5 min, 16.5–17 min, 17–17.5 min, 17.5–18 min, 18–18.5 min, 18.5–19 min, 19–19.5 min, 19.5–20 min or longer.

[0046] In some embodiments of the present invention, the mass percentage of sodium chloride particles in the granular slurry is 62% ± 3%.

[0047] In some embodiments of the present invention, the height difference between the top liquid level of the gravity concentration unit and the addition point required for the salting-out process is more than 12m, and can be 12-12.5m, 12.5-13m, 13-13.5m, 13.5-14m, 14-14.5m, 14.5-15m or greater.

[0048] In some embodiments of the present invention, the quantitative dosing unit uses a pipeline fluid metering method for quantitative dosing, and the pipeline fluid metering method is usually a metering method with no change in pipe diameter when the pipe is full, such as electromagnetic flow meter metering.

[0049] A second aspect of the present invention provides a quantitative dosing system for industrial wet salt particles, comprising a wet salt dissolving unit 102, a conveying unit 103, a gravity concentration unit 104, and a quantitative dosing unit 105;

[0050] The wet salt preparation unit 102 is equipped with an industrial wet salt inlet, a makeup water inlet and a high-concentration sodium chloride suspension outlet, and is used to prepare a high-concentration sodium chloride suspension.

[0051] The conveying unit 103 includes a conveying pump and a conveying pipeline connected to the outlet of the conveying pump, for stably conveying the high-concentration sodium chloride suspension to the gravity concentration unit 104 at a high position; the suction pipe of the conveying pump is connected to the outlet of the high-concentration sodium chloride suspension of the wet salt unit 102.

[0052] The gravity concentration unit 104 is equipped with a sodium chloride high-concentration suspension inlet, a clarified saturated sodium chloride solution outlet, and a granular slurry outlet, and is used to gravity concentrate the sodium chloride high-concentration suspension to obtain a granular slurry with a stable solid-liquid ratio; the sodium chloride high-concentration suspension inlet is connected to the conveying pipeline of the conveying unit 103;

[0053] The quantitative dosing unit 105 is located on the pipeline connecting the particle slurry outlet of the gravity concentration unit 104 and the dosing point required for the salting-out process, and is used to achieve stable sodium chloride dosing.

[0054] In some embodiments of the present invention, the system further includes a feeding unit 101 for adding industrial wet salt to the industrial wet salt inlet of the wet salt processing unit 102. In some embodiments of the present invention, the feeding unit 101 includes a weighing bucket shovel for quantitatively adding industrial wet salt to the industrial wet salt inlet of the wet salt processing unit. Preferably, the weighing bucket shovel has an automatic tipping function, enabling it to perform all functions such as shoveling, weighing, and unloading during operation.

[0055] In this invention, the wet salt processing unit 102 is equipped with a wet salt container capable of holding a certain volume. The industrial wet salt inlet is located at the top of the wet salt container, facilitating the pouring of wet salt into the container. In some embodiments of this invention, a stirring device is provided inside the wet salt container. In some embodiments of this invention, the wet salt processing unit 102 further includes a detection bypass and a suspension concentration detection device 201, facilitating the sampling and detection of the concentration of the high-concentration sodium chloride suspension, and controlling the dosage of industrial wet salt based on the concentration of the high-concentration sodium chloride suspension; the detection bypass is used to send the material in the wet salt container to the suspension concentration detection device 201, and after detection, the material is returned to the wet salt container. In this invention, the suspension concentration detection device 201 includes a measuring cylinder for detecting the sodium chloride particle settling ratio of the high-concentration sodium chloride suspension.

[0056] In some embodiments of the present invention, the conveying pump is selected from an open centrifugal pump or a screw pump. Centrifugal pumps have open impellers, semi-open impellers, and closed impellers; open impellers consist only of blades and blade reinforcing ribs, without front and rear cover plates. If a non-open impeller is selected, the solid content will form a sedimentation zone on the front and rear cover plates, and then remain around the impeller. Over time, this will lead to particle accumulation and impeller failure. Screw pumps are effective conveying devices for conveying materials containing high concentrations of particulate matter. The main working components of a screw pump consist of a bushing (stator) with a double-headed helical cavity and a single-headed eccentric screw (rotor) meshing with it within the stator cavity. The conveyed medium is axially and uniformly propelled, resulting in low internal flow velocity, stable pressure, and no eddy currents or agitation, making it suitable for conveying high-concentration sodium chloride suspensions in the present invention.

[0057] In some embodiments of the present invention, the gravity concentration unit 104 is equipped with a stirring device, preferably a low-speed stirring device. In this invention, the gravity concentration unit 104 is equipped with a container capable of holding a certain volume, the stirring device is located inside the container, the outlet of the clarified saturated sodium chloride solution is located at the top of the container, a storage area is located at the bottom of the container, and the granular slurry outlet is located at the bottom of the container. The granular slurry can flow by gravity from a high position into the dosing pipeline, and after passing through the quantitative dosing unit 105 on the dosing pipeline, it is sent to the dosing point required for the salting-out process. Preferably, the height difference between the top liquid level of the gravity concentration unit 104 and the dosing point required for the salting-out process is more than 12m. Since the mass ratio of sodium chloride particles in the granular slurry obtained after gravity concentration is more than 60%, the material has very poor fluidity, requiring a sufficiently large static pressure difference when flowing downwards. The height difference of more than 12m is determined based on the actual operating conditions of the system.

[0058] In some embodiments of the present invention, the system further includes a reflux device 106, which has a clarified saturated sodium chloride solution inlet and a reflux liquid outlet, for recycling the clarified saturated sodium chloride solution to the wet salt preparation unit 102; the clarified saturated sodium chloride solution inlet is connected to the clarified saturated sodium chloride solution outlet of the gravity concentration unit 104, and the reflux liquid outlet is connected to the reflux liquid inlet of the wet salt preparation unit 102. Preferably, the reflux device 106 is selected from a gravity-flow device. In some preferred embodiments of the present invention, a heat exchanger 107 is further provided on the connecting pipeline between the reflux liquid outlet of the reflux device 106 and the reflux liquid inlet of the wet salt preparation unit 102, for heating the clarified saturated sodium chloride solution to further improve the saturated solubility limit of the aqueous solution, thereby avoiding pipe blockage caused by wall cooling during conventional transportation.

[0059] In some embodiments of the present invention, the quantitative dosing unit 105 includes a dosing adjustment device 202 and a dosing metering device 203. The dosing adjustment device 202 is used to adjust the flow rate of the granular slurry, and the dosing metering device 203 is used to accurately meter the amount of granular slurry added, thereby ensuring that the accuracy of the granular slurry delivery is within 0.5 wt%. Preferably, the dosing adjustment device 202 is selected from a V-type ball valve. Preferably, the dosing metering device 203 is selected from an electromagnetic flowmeter.

[0060] From the perspective of overall system operation, once the system volume and internal rotation speed are determined, the solid content (mass percentage of sodium chloride particles) in the granular slurry obtained after gravity concentration can be stably maintained within 62% ± 3%. Therefore, the amount of sodium chloride added is only related to the accuracy of the system's delivery rate. Ultimately, the delivery accuracy of industrial wet salt is within ± 1%, which is significantly higher than the delivery accuracy when adding dry industrial dry salt, far exceeding the expected results.

[0061] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0062] Example 1

[0063] The flowchart of the quantitative dosing system for industrial wet salt particles in this embodiment is as follows: Figure 1 As shown: It includes a feeding unit weighing bucket 101; a salt-wetting unit 102; a conveying device 103; a gravity concentration unit 104; a quantitative dosing unit 105; and a reflux device 106.

[0064] The feeding unit 101 includes a weighing bucket and a fixed weighbridge. The weighing bucket is a slanted bucket with dimensions of 1.5m × 1m × 1m made of 304 steel plate. It has mechanical shoveling and tipping functions, and can easily complete the operation of shoveling wet salt. The weighbridge can be used to know the weight of wet salt added before and after each shovel. It can be combined with the suspension concentration detection device 201 of the wet salt processing unit 102 to perform preliminary control of the concentration of materials in the wet salt processing unit.

[0065] The wet salt unit 102 includes a wet salt container and a suspension concentration detection device 201. The wet salt container is a reinforced concrete water tank with a diameter of 2.4m and a height of 1.5m, and the tank is lined with PE board. The wet salt container is equipped with an anchor frame mixer with a diameter of 2.2m and two 45-degree inclined propellers with a diameter of 1m inside, with a stirring power of 7.5KW. The wet salt container is equipped with a detection bypass, and a sampling port is set on the detection bypass. Manual sampling is performed every 15 minutes, and the sodium chloride particle sedimentation ratio of the high concentration sodium chloride suspension is determined by the suspension concentration detection device 201.

[0066] The conveying device 103 includes one open centrifugal pump with a flow rate of 1 m³ / s. 3 / h, with a head of 40m, used to transport the high-concentration sodium chloride suspension obtained in the wet salt container to the gravity concentration unit 104.

[0067] The gravity concentration unit 104 includes a gravity concentration tank installed on the 4th floor, with a diameter of 1m, a straight height of 1.5m, and an inclined bucket height of 0.8m. The inclined bucket area is equipped with a mixer with a speed of 10min / rad and a power of 0.55KW.

[0068] The quantitative dosing unit 105 includes a dosing adjustment device 202 and a dosing metering device 203. The dosing adjustment device 202 is a V-type ball valve installed on the dosing pipeline (DN20 pipeline) connecting the granular slurry outlet of the gravity concentration unit 104 to the dosing point required for the salting-out process. The dosing metering device 203 is an electromagnetic flowmeter installed on the DN20 pipeline at the dosing point required for the salting-out process, used to achieve stable sodium chloride dosing.

[0069] The reflux device 106 includes a gravity-type self-flow device, which can reflux the clarified saturated sodium chloride solution obtained from the gravity concentration unit 104 back to the wet salt container of the wet salt unit 102.

[0070] The quantitative addition method of industrial wet salt granules in this embodiment includes the following steps:

[0071] S1. Weigh industrial wet salt (moisture content 0.8wt%~4wt%) through weighing bucket shovel 101 and add it to the wet salt container of wet salt unit 102 through industrial wet salt inlet. Turn on anchor frame mixer to prepare high concentration sodium chloride suspension. Manually take samples from the detection bypass of wet salt container every 15 minutes and determine the sodium chloride particle sedimentation ratio through suspension concentration detection device (1000mL graduated cylinder). Control the sodium chloride particle sedimentation ratio to be 25%~40%.

[0072] S2. Start the open centrifugal pump to transport the high-concentration sodium chloride suspension from the wet salt unit 102 to the gravity concentration tank of the gravity concentration unit 104 at the high position. Start the agitator in the inclined bucket area 2 of the gravity concentration tank and keep it in place for 20 minutes to obtain a clear saturated sodium chloride solution in the upper part and a granular slurry with stable solid content in the lower part. The mass percentage of sodium chloride particles in the granular slurry is 62% ± 0.5%.

[0073] S3. Open the granular slurry outlet located at the bottom of the gravity thickening tank, so that the granular slurry flows from the high position into the addition pipeline through the pipeline. The opening and closing of the V-type ball valve 202 controls the delivery of the granular slurry from the gravity thickening unit 104 to the addition point required for the salting-out process, and the electromagnetic flowmeter 203 at the addition point realizes the quantitative addition of sodium chloride.

[0074] S4. The clarified saturated sodium chloride solution located at the top of the gravity concentration tank enters the reflux device 106 and is reused in the wet salt unit 102.

[0075] The system of this embodiment is used for industrial wet salt addition. The settling ratio of sodium chloride particles in the wet salt preparation unit 102 and the particle concentration (mass percentage of sodium chloride particles) at the discharge point from the V-type ball valve 202 are tracked. The sodium chloride dosage at this discharge point is verified using a drying and weighing method. The dosage for different discharge requirements is shown in Table 1 below:

[0076] Table 1

[0077] 178 62.1％ 177.2 245 62.2％ 243.1 300 62.2％ 298.7

[0078] As shown in Table 1, the quantitative dosing system for industrial wet sodium chloride particles provided in this embodiment has dosing deviations of 0.4%, -0.7%, and 0.4%, respectively, and the dosing accuracy is within ±1%.

[0079] Example 2

[0080] The flowchart of the quantitative dosing system for industrial wet salt particles in this embodiment is as follows: Figure 2 As shown: In addition to the same parts as in Example 1, a tubular heat exchanger 107 is also provided on the connecting pipe between the reflux outlet of the reflux device 106 and the reflux inlet of the wet salt unit 102, for heating the clarified saturated sodium chloride solution.

[0081] In addition to the same steps as in Example 1, the quantitative addition method of industrial wet salt particles in this embodiment also includes introducing the clarified saturated sodium chloride solution located at the top of the gravity concentration tank into the tubular heat exchanger 107, heating it to 15°C, and then sending it into the reflux device 106. The saturated solubility limit of the aqueous solution is further increased by heating to avoid pipe blockage caused by wall cooling during the conventional transportation process.

[0082] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for quantitatively adding industrial wet salt granules, characterized in that, Includes the following steps: S1. Weigh the industrial wet salt and add it to the wet salt dissolving unit to obtain a high-concentration sodium chloride suspension; the moisture content of the industrial wet salt is 0.8wt%~4wt%; the sodium chloride particle settling ratio of the high-concentration sodium chloride suspension is 25%~40%; S2. The high-concentration sodium chloride suspension is transported to a gravity concentration unit at a high level to obtain a clear, saturated sodium chloride solution and a granular slurry with stable solid content; the height difference between the top liquid level of the gravity concentration unit and the addition point required for the salting-out process is greater than 12 m; the residence time of the gravity concentration unit is greater than 15 min; the mass percentage of sodium chloride particles in the granular slurry is 62% ± 3%. S3. The granular slurry flows into the dosing pipeline from a high position by gravity, and is delivered to the dosing point required for the salting-out process through the quantitative dosing unit on the dosing pipeline, so as to achieve precise dosing of sodium chloride; the quantitative dosing unit uses the pipeline fluid metering method to do quantitative dosing; S4. Send the clear saturated sodium chloride solution into the reflux device and reuse it in the wet salt unit.

2. A quantitative dosing system for industrial wet salt granules, characterized in that, It includes a wet salt dissolving unit (102), a conveying unit (103), a gravity concentration unit (104), and a quantitative dosing unit (105). The wet salt preparation unit (102) is equipped with an industrial wet salt inlet, a makeup water inlet and a high-concentration sodium chloride suspension outlet, and is used to prepare a high-concentration sodium chloride suspension. The conveying unit (103) includes a conveying pump and a conveying pipeline connected to the outlet of the conveying pump, for stably conveying the high-concentration sodium chloride suspension to the gravity concentration unit (104) at a high position; the suction pipe of the conveying pump is connected to the outlet of the high-concentration sodium chloride suspension of the wet salt unit (102). The gravity concentration unit (104) is provided with a sodium chloride high-concentration suspension inlet, a clarified saturated sodium chloride solution outlet and a granular slurry outlet, which is used to gravity concentrate the sodium chloride high-concentration suspension to obtain a granular slurry with a stable solid-liquid ratio; the sodium chloride high-concentration suspension inlet is connected to the conveying pipeline of the conveying unit (103); The quantitative dosing unit (105) is located on the pipeline connecting the particle slurry outlet of the gravity concentration unit (104) and the dosing point required for the salting-out process, and is used to achieve stable sodium chloride dosing.

3. The quantitative dosing system for industrial wet salt particles as described in claim 2, characterized in that, Includes one or more of the following characteristics: a) It also includes a feeding unit (101) for adding industrial wet salt to the industrial wet salt inlet of the wet salt processing unit (102); b) The wet salt unit (102) also includes a detection bypass and a suspension concentration detection device (201) to facilitate sampling and detection of the concentration of high-concentration sodium chloride suspension; c) The gravity concentration unit (104) is equipped with a stirring device; d) The height difference between the top liquid level of the gravity concentration unit (104) and the addition point required for the salting-out process is more than 12 m.

4. The quantitative dosing system for industrial wet salt particles as described in claim 3, characterized in that, The feeding unit (101) includes a weighing shovel; and / or, the suspension concentration detection device is selected from a graduated cylinder.

5. The quantitative dosing system for industrial wet salt particles as described in claim 2, characterized in that, It also includes a reflux device (106) with a clarified saturated sodium chloride solution inlet and a reflux liquid outlet, for recycling the clarified saturated sodium chloride solution to the wet salt unit (102); the clarified saturated sodium chloride solution inlet is connected to the clarified saturated sodium chloride solution outlet of the gravity concentration unit (104), and the reflux liquid outlet is connected to the reflux liquid inlet of the wet salt unit (102).

6. The quantitative dosing system for industrial wet salt particles as described in claim 5, characterized in that, The reflux device (106) is selected from a gravity-flow device; and / or, a heat exchanger (107) is also provided on the connecting pipeline between the reflux outlet of the reflux device (106) and the reflux inlet of the wet salt unit (102) for temperature regulation of the clarified saturated sodium chloride solution.

7. The quantitative dosing system for industrial wet salt particles as described in claim 2, characterized in that, The quantitative dosing unit (105) includes a dosing adjustment device (202) and a dosing metering device (203). The dosing adjustment device (202) is used to adjust the flow rate of the granular slurry, and the dosing metering device (203) is used to accurately measure the amount of granular slurry added.

8. The quantitative dosing system for industrial wet salt particles as described in claim 7, characterized in that, Includes at least one of the following technical features: a) The dosing adjustment device (202) is selected from a V-type ball valve; b) The metering device (203) is selected from an electromagnetic flowmeter.

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