A salt storage for automatic unloading and adding salt and a method for automatic unloading and adding salt

Abstract

The present invention discloses a salt depot with automatic unloading and salt adding and an automatic unloading and salt adding method, comprising a unloading pit and a stockpiling area, wherein a flap unloading platform is provided on the feeding side of the unloading pit, a first traveling crane grab is provided above the unloading pit, a second traveling crane grab is provided above the stockpiling area, a conveying device is provided on the discharging side of the stockpiling area, and a salting tank is provided at the end of the conveying device; the present invention can reduce labor intensity, improve the reliability of salt adding operation, ensure the stability of brine concentration, and facilitate the inventory of inventory and salt consumption.

Description

Technical Field

[0001] The invention relates to the technical field of salt depot automation in the chlor-alkali industry, and in particular to a salt depot with automatic salt unloading and adding and an automatic salt unloading and adding method. Background Art

[0002] In the chlor-alkali industry, industrial salt, the raw material for ion-exchange membrane caustic soda, is typically transported to salt depots by salt trucks. Unloading is performed manually on-site, and then stacked and added by forklifts. Salt collectors must verify the number and tonnage of unloaded salt trucks, and salt consumption also requires verification by on-site personnel. Uncertainty regarding the type of salt trucks leads to labor uncertainty, and methods for calculating incoming and added salt tonnage are crude and labor-intensive. The forklift-based salt addition process is highly unstable, and frequent salt additions lead to low brine concentrations, resulting in substandard sodium hydroxide produced by the chlor-alkali plant. To significantly reduce labor intensity, improve the reliability of salt addition operations, ensure brine concentration stability, and facilitate inventory management of salt levels and consumption, necessary reforms are necessary. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a salt storage and a method for automatic unloading and salt adding, which can reduce labor intensity, improve the reliability of salt adding operation, ensure the stability of brine concentration, and facilitate inventory of inventory and salt consumption.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a salt storage with automatic unloading and salt adding, comprising a unloading pit and a stacking area, a flap unloading platform is provided on the feeding side of the unloading pit, a first traveling crane grab is provided above the unloading pit, a second traveling crane grab is provided above the stacking area, a conveying equipment is provided on the discharging side of the stacking area, and a salting pool is provided at the end of the conveying equipment.

[0005] Preferably, the control end of the flap unloading platform is connected to the output end of the unloading platform PLC controller, and an inclinometer and a monitoring camera are provided on the flap unloading platform, and the inclinometer and the monitoring camera are connected to the unloading platform PLC controller.

[0006] Preferably, the control ends of the first crane grab and the second crane grab are both connected to the output ends of the corresponding crane PLC controller, and the first crane grab and the second crane grab are both provided with weighing sensors, 3D scanners, monitoring cameras, and infrared rangefinders, and the weighing sensors, 3D scanners, monitoring cameras, and infrared rangefinders are all connected to the crane PLC controller.

[0007] Preferably, the conveying equipment includes a storage crusher, a vibrating feeder, and a scraper. The storage crusher, vibrating feeder, scraper and salt tank are all connected to the conveying equipment PLC controller, and the unloading platform PLC controller, the crane PLC controller and the conveying equipment PLC controller are all connected to the DCS control system, and the DCS control system is connected to the monitoring video.

[0008] Preferably, the first crane grab bucket is a 16T crane grab bucket, and the second crane grab bucket is a 10T crane grab bucket.

[0009] In addition, the present invention also discloses an automatic unloading and salting method for the salt storage for automatic unloading and salting, which comprises the following steps:

[0010] S1: Open the side unloading lane gate, and the side unloading salt truck drives into the unloading pit to unload salt; open the front top dump unloading lane gate, and the front top dump truck drives into the unloading pit to unload salt;

[0011] S2: The non-self-unloading salt truck is unloaded onto the flip-plate unloading platform. The unloading platform PLC controller controls the tilt of the flip-plate unloading platform to unload the salt from the non-self-unloading salt truck.

[0012] S3: The DCS control system issues a salt transfer command to the crane PLC controller to control the first crane grab bucket to transfer the salt in the unloading pit to the stockpile area;

[0013] S4: The DCS control system issues a salt adding command, and the crane PLC controller controls the second crane grab bucket to add the salt in the stockpile area to the storage crusher;

[0014] S5: The storage crusher starts, and the conveying equipment PLC controller automatically starts and stops the vibrating feeder and scraper, thereby sending the salt into the salt tank.

[0015] Preferably, in step S2, the unloading platform PLC controller controls the tilt angle of the flap unloading platform to be ≥55° when unloading refined salt, and the tilt angle to be ≥32° when unloading crude salt.

[0016] Preferably, in step S4, the crane PLC controller controls the second crane grab bucket to increase the amount of salt caught per hour according to the following formula:

[0017] The amount of salt required per hour M = 0.47 * total current of chlor-alkali electrolysis I, where M is in tons and I is in KA.

[0018] Preferably, in step S4, the crane PLC controller controls the second crane grab bucket to intermittently grab salt to the storage crusher according to the following formula:

[0019] Number of salt buckets per hour N = amount of salt to be added per hour M / expected weight of salt to be caught per bucket m;

[0020] The interval time between the first bucket and the second bucket for collecting and releasing salt is T1 = 60 minutes / the number of salt collecting buckets per hour N;

[0021] If the first bucket actually releases M1 tons of salt, then the interval between the second and third buckets is T2 = (60-T1) / [(M-M1) / m];

[0022] If the second bucket actually releases M2 tons of salt, then the interval between the third and fourth buckets releasing salt is T3 = (60-T1-T2) / [(M-M1-M2) / m];

[0023] If the third bucket actually releases M3 tons of salt, then the interval between the fourth and fifth buckets releasing salt is T4 = (60-T1-T2-T3) / [(M-M1-M2-M3) / m];

[0024] Similarly, the interval time for catching and releasing salt in the next bucket is updated in real time;

[0025] The units of M, M1, M2, M3 and m are tons, and the units of T1, T2, T3 and T4 are minutes.

[0026] Preferably, in step S5, when the no-load current of the storage crusher rises from 24A to 26A with material, the conveying equipment PLC controller starts the vibrating feeder and the scraper conveyor in sequence; when the current of the storage crusher drops to 24A, the conveying equipment PLC controller stops the scraper conveyor and the vibrating feeder in sequence.

[0027] Beneficial effects of the present invention:

[0028] 1. The present invention can reduce labor intensity, improve the reliability of salt addition operation, ensure the stability of brine concentration, and facilitate inventory of inventory and salt consumption.

[0029] 2. In the actual process of collecting and releasing salt, the amount of salt collected and released in each bucket cannot be completely consistent. In fact, the amount of salt collected and released is between 2 tons and 3.5 tons. Therefore, after each actual collection and release of a corresponding amount of salt, the present invention updates it through a corresponding calculation formula, and then adjusts the time interval for the next collection and release of salt. This is equivalent to the correction process of the theoretical number of salt-added buckets and the actual number of salt-added buckets after weighing, making the entire salt-collecting and releasing process more controllable and stable, improving the reliability of the salt-adding operation, and ensuring the stability of the subsequent brine concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the process structure of a salt storage with automatic unloading and salting;

[0031] Figure 2 This is a schematic diagram of the planar structure of a salt storage with automatic unloading and salt addition;

[0032] Figure 3The present invention is a structural schematic diagram of a flap unloading platform. DETAILED DESCRIPTION

[0033] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figures 1 to 3 As shown, a salt depot with automatic unloading and salt addition includes a unloading pit 2 and a stockpiling area 3. The unloading pit 2 is provided with a flap unloading platform 1 on the feeding side, a first driving grab bucket 4 is provided above the unloading pit 2, and a second driving grab bucket 5 is provided above the stockpiling area 3. A conveying device is provided on the discharge side of the stockpiling area 3, and a salting tank 9 is provided at the end of the conveying device. In this embodiment, the west side of the unloading pit 2 is a +0.6m side unloading platform for salt trucks, and the right side of the side unloading platform is a -3m unloading deep pit. The northern part of the easternmost part is a slope from -0m to -3m, and the southeastern part of the unloading pit 2 is a -3m pit.

[0035] Preferably, the control end of the flap unloading platform 1 is connected to the output end of the unloading platform PLC controller 10, and an inclinometer and a monitoring camera are provided on the flap unloading platform 1, and the inclinometer and the monitoring camera are connected to the unloading platform PLC controller 10.

[0036] Preferably, the control ends of the first crane grab 4 and the second crane grab 5 are connected to the output ends of the corresponding crane PLC controller 11, and the first crane grab 4 and the second crane grab 5 are provided with weighing sensors, 3D scanners, monitoring cameras, and infrared rangefinders, and the weighing sensors, 3D scanners, monitoring cameras, and infrared rangefinders are all connected to the crane PLC controller 11.

[0037] Preferably, the conveying equipment includes a hopper crusher 6, a vibrating feeder 7, and a scraper 8. The hopper crusher 6, vibrating feeder 7, scraper 8, and salt tank 9 are all connected to a conveying equipment PLC controller 12. The unloading platform PLC controller 10, the driving PLC controller 11, and the conveying equipment PLC controller 12 are all connected to a DCS control system 13, which is connected to a monitoring video. In this embodiment, the vibrating feeder 7 is located in the hopper crusher 6 to control its discharging process, and the scraper 8 transports the material to the salt tank 9.

[0038] Preferably, the first crane grab bucket 4 is a 16T crane grab bucket, and the second crane grab bucket 5 is a 10T crane grab bucket.

[0039] In addition, the present invention also discloses an automatic unloading and salting method for the salt storage for automatic unloading and salting, which comprises the following steps:

[0040] S1: Open the side unloading lane gate, and the side unloading salt truck drives into the unloading pit 2 to unload salt; open the front top dump unloading lane gate, and the front top dump truck drives into the unloading pit 2 to unload salt;

[0041] S2: The non-self-unloading salt truck is unloaded onto the flap unloading platform 1, and the unloading platform PLC controller 10 controls the flap unloading platform 1 to tilt and unload the salt from the non-self-unloading salt truck;

[0042] S3: The DCS control system 13 issues a salt transfer command to the PLC controller 11 to control the first traveling grab bucket 4 to transfer the salt in the unloading pit 2 to the stockpiling area 3. In this step, the 3D scanner of the first traveling grab bucket 4 scans the salt layer height, automatically identifies the high-salt layer, grabs the salt and places it in the set salt discharge area. When it is placed in the low-salt layer, the upper limit of the salt layer discharge is 3.5m. If it is higher than 3.5m, move to other low-salt layer positions in the discharge area. The upper limit of the salt layer grabbing is 1.5m. If it is lower than 1.5m, move to other positions to grab salt.

[0043] S4: The DCS control system 13 issues a salt addition command, and the crane PLC controller 11 controls the second crane grab bucket 5 to add salt from the stockpile area 3 to the storage crusher 6. In this step, when grabbing salt, the 3D scanner scans the salt layer height, automatically identifies the high-salt layer, and then adds the grabbed salt to the storage crusher 6.

[0044] S5: The storage crusher 6 is started, and the conveying equipment PLC controller 12 automatically starts and stops the vibrating feeder 7 and the scraper 8, thereby feeding the salt into the salting tank 9.

[0045] In addition, in the event of a fault, the forklift lane gate at the northwest corner of stockpile area 3 is opened, the forklift is used to add salt, and the driving grab is shut down.

[0046] Preferably, in step S2, the unloading platform PLC controller 10 controls the tilt angle of the flap unloading platform 1 to be ≥55° when unloading refined salt, and ≥32° when unloading crude salt.

[0047] In this embodiment, the selection of the above-mentioned inclination angle range is supported by the following data: Table 1 shows the physical and chemical properties of refined salt and crude salt;

[0048] Table 1 Physicochemical properties of refined salt and crude salt

[0049]

[0050] The relationship between the unloading angle and the unloading amount of the flip unloading platform test is as follows:

[0051] 1. For the same truck of coarse salt, adjust the tipping angle starting from 0°. The relationship is shown in Table 2:

[0052] Table 2 Changes in unloading angle and unloading amount of crude salt from the same truck

[0053]

[0054] 2. For different vehicles with coarse salt, adjust the tipping angle starting from 0°. The relationship is shown in Table 3:

[0055] Table 3 Changes in unloading angles and unloading amounts of crude salt from different trucks

[0056]

[0057] In summary, although the coarse salt repose angle is 27°, in the actual experimental unloading process, when the coarse salt reaches 32°, the unloading ratio can reach more than 98.5%, and 0.1-0.5 tons of salt remain in the carriage, which is a small amount that can be easily cleaned by manual labor. Therefore, it is best to choose an inclination angle of more than 32°.

[0058] 3. For the same truck of refined salt, adjust the tipping angle starting from 0°. The relationship is shown in Table 4:

[0059] Table 4 Changes in unloading angle and unloading amount of refined salt from the same truck

[0060]

[0061] 4. For different vehicles with refined salt, adjust the tipping angle starting from 0°. The relationship is shown in Table 5:

[0062] Table 5 Changes in unloading angles and unloading amounts of refined salt from different trucks

[0063]

[0064] In summary, although the repose angle of refined salt is 43°, in the actual experimental unloading process, when the refined salt reaches 55°, the unloading ratio can reach more than 98.5%, and 0.1-0.6 tons remain in the carriage, which can be cleaned with a small amount of manual labor. Therefore, it is better to choose an inclination angle of more than 55°.

[0065] Preferably, in step S4, the crane PLC controller 11 controls the second crane grab bucket 5 to increase the amount of salt captured per hour according to the following formula:

[0066] The amount of salt required per hour M = 0.47 * total current of chlor-alkali electrolysis I, where M is in tons and I is in KA.

[0067] Through the load and salt addition comparison table, the relationship between the amount of salt required per hour and the total current of chlor-alkali electrolysis can be obtained, as shown in Table 6 below.

[0068] Table 6 Comparison table of current load and salt addition amount

[0069] Current (KA) Single circuit consumption (T / h) Dual circuit consumption (T / h) Three-circuit consumption (T / h) Four-circuit consumption (T / h) 5 2.4 4.8 7.2 9.6 6 2.9 5.8 8.7 11.6 7 3.4 6.8 10.2 13.6 8 3.8 7.6 11.4 15.2 9 4.3 8.6 12.9 17.2 10 4.8 9.6 14.4 19.2 11 5.3 10.6 15.9 21.2 12 5.8 11.6 17.4 23.2 13 6.3 12.6 18.9 25.2 14 6.7 13.4 20.1 26.8 15 7.2 14.4 21.6 28.8 16 7.7 15.4 23.1 30.8 17 8.1 16.2 24.3 32.4 18 8.6 17.2 25.8 34.4

[0070] Preferably, in step S4, the crane PLC controller 11 controls the second crane grab bucket 5 to intermittently grab salt to the storage crusher 6 according to the following formula:

[0071] Number of salt buckets per hour N = amount of salt to be added per hour M / expected weight of salt to be caught by a single bucket m ;

[0072] The interval time between the first bucket and the second bucket for collecting and releasing salt is T1 = 60 minutes / the number of salt collecting buckets per hour N;

[0073] If the first bucket actually releases M1 tons of salt, then the interval between the second and third buckets is T2 = (60-T1) / [(M-M1) / m];

[0074] If the second bucket actually releases M2 tons of salt, then the interval between the third and fourth buckets releasing salt is T3 = (60-T1-T2) / [(M-M1-M2) / m];

[0075] If the third bucket actually releases M3 tons of salt, then the interval between the fourth and fifth buckets releasing salt is T4 = (60-T1-T2-T3) / [(M-M1-M2-M3) / m];

[0076] Similarly, the interval time for catching and releasing salt in the next bucket is updated in real time;

[0077] The units of M, M1, M2, M3 and m are tons, and the units of T1, T2, T3 and T4 are minutes.

[0078] In this step, the amount of salt added per hour M = 0.47 * total current of chlor-alkali electrolysis I, and the expected single bucket salt weight m is a fixed value or a design value, which is related to the shape and size of the grab bucket itself. In this embodiment, the expected single bucket salt weight m of the second traveling grab bucket 5 is 2.5 tons; in the actual process of grabbing and releasing salt, the amount of salt grabbed and released by each bucket cannot be completely consistent. In fact, the amount of salt grabbed and released is between 2 tons and 3.5 tons. Therefore, after each actual amount of salt is grabbed and released, this embodiment is updated through the above calculation formula, and then the time interval for the next salt grabbing and releasing is adjusted. This is equivalent to the correction process of the theoretical number of salt-added buckets and the actual number of salt-added buckets after weighing, making the entire salt-grabbing and releasing process more controllable and stable, improving the reliability of the salt-adding operation, and ensuring the subsequent brine concentration stability.

[0079] In addition, in actual production, the above salt grabbing time interval includes the time for the grab bucket to grab and release salt once and the time for the grab bucket to wait for grabbing and releasing salt. The grab bucket itself usually takes 5 minutes to grab and release salt once, so the time interval between grabbing and releasing salt should be greater than 5 minutes. If the hourly salt addition task has not been completed at the end of an hour, and the salt grabbing and releasing interval time is less than 5 minutes, the unfinished salt addition amount will be counted as the salt addition amount required for the next hour.

[0080] If the amount of salt added in one hour is exceeded, the corresponding amount will be deducted from the amount of salt added in the next hour.

[0081] Preferably, in step S5, when the no-load current of the hopper crusher 6 rises from 24A to 26A with material, the conveying equipment PLC controller 12 sequentially starts the vibrating feeder 7 and the scraper 8. When the current of the hopper crusher 6 drops to 24A, the conveying equipment PLC controller 12 sequentially stops the scraper 8 and the vibrating feeder 7. With this control, the vibrating feeder 7 and the scraper 8 are only started when material is present in the hopper crusher 6, thereby saving energy and production costs.

[0082] In addition, the operating current of the vibrating feeder in this embodiment is controlled at 7.5A. Under this current, its conveying capacity of refined salt is 35T / h and its conveying capacity of coarse salt is 42T / h. There are three scrapers, and the controlled conveying capacity is 45T / h.

[0083] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for automatically unloading and adding salt in a salt depot, wherein the salt depot comprises an unloading pit (2) and a stacking area (3), and is characterized in that: The unloading pit (2) is provided with a flap unloading platform (1) on the feeding side, a first traveling crane grab bucket (4) is provided above the unloading pit (2), a second traveling crane grab bucket (5) is provided above the stacking area (3), a conveying device is provided on the discharge side of the stacking area (3), and a salting pool (9) is provided at the end of the conveying device; it is characterized in that it comprises the following steps: S1: Open the side unloading lane gate, and the side unloading salt truck drives into the unloading pit (2) to unload salt; open the front top dump unloading lane gate, and the front top dump truck pours into the unloading pit (2) to unload salt; S2: The non-self-unloading salt truck is unloaded onto the flip-plate unloading platform (1), and the unloading platform PLC controller (10) controls the flip-plate unloading platform (1) to tilt, thereby unloading the salt from the non-self-unloading salt truck; S3: The DCS control system (13) issues a salt transfer command to the PLC controller (11) to control the first crane grab bucket (4) to transfer the salt in the unloading pit (2) to the stockpile area (3); S4: The DCS control system (13) issues a salt adding command, and the crane PLC controller (11) controls the second crane grab bucket (5) to add the salt in the stockpile area (3) to the storage crusher (6); S5: The storage crusher (6) starts, and the conveying equipment PLC controller (12) automatically starts and stops the vibrating feeder (7) and the scraper (8), thereby feeding the salt into the salting tank (9); In step S4, the crane PLC controller (11) controls the second crane grab bucket (5) to intermittently grab salt to the storage crusher (6) according to the following formula: Number of salt buckets per hour N = amount of salt to be added per hour M / expected weight of salt caught by a single bucket m; The interval time between the first bucket and the second bucket for collecting and releasing salt is T1 = 60 minutes / the number of salt collecting buckets per hour N; If the first bucket actually releases M1 tons of salt, then the interval between the second and third buckets is T2 = (60-T1) / [(M-M1) / m]; If the second bucket actually releases M2 tons of salt, then the interval between the third and fourth buckets is T3 = (60-T1-T2) / [(M-M1-M2) / m]; If the third bucket actually releases M3 tons of salt, then the interval between the fourth and fifth buckets is T4 = (60-T1-T2-T3) / [(M-M1-M2-M3) / m]; Similarly, the interval time for catching and releasing salt in the next bucket is updated in real time; The units of M, M1, M2, M3 and m are tons, and the units of T1, T2, T3 and T4 are minutes.

2. The method for automatically unloading and adding salt in a salt storage according to claim 1 is characterized in that: The control end of the flap unloading platform (1) is connected to the output end of the unloading platform PLC controller (10). An inclination meter and a monitoring camera are provided on the flap unloading platform (1), and the inclination meter and the monitoring camera are connected to the unloading platform PLC controller (10).

3. The automatic unloading and salting method for a salt storage for automatic unloading and salting according to claim 2 is characterized in that: The control ends of the first crane grab (4) and the second crane grab (5) are connected to the output ends of the corresponding crane PLC controller (11). The first crane grab (4) and the second crane grab (5) are both provided with a weighing sensor, a 3D scanner, a monitoring camera, and an infrared rangefinder. The weighing sensor, the 3D scanner, the monitoring camera, and the infrared rangefinder are all connected to the crane PLC controller (11).

4. The method for automatically unloading and adding salt in a salt storage according to claim 3 is characterized in that: The conveying equipment includes a storage crusher (6), a vibrating feeder (7), and a scraper (8). The storage crusher (6), the vibrating feeder (7), the scraper (8), and the salt tank (9) are all connected to a conveying equipment PLC controller (12). The unloading platform PLC controller (10), the driving PLC controller (11), and the conveying equipment PLC controller (12) are all connected to a DCS control system (13). The DCS control system (13) is connected to a monitoring video.

5. The automatic unloading and salting method for a salt storage for automatic unloading and salting according to claim 1 is characterized in that: The first traveling crane grab bucket (4) is a 16T traveling crane grab bucket, and the second traveling crane grab bucket (5) is a 10T traveling crane grab bucket.

6. The method for automatically unloading and adding salt in a salt storage according to claim 1, characterized in that: In step S2, the unloading platform PLC controller (10) controls the tilting plate unloading platform (1) to have an inclination angle of ≥55° when unloading refined salt and an inclination angle of ≥32° when unloading crude salt.

7. The automatic unloading and salting method for a salt storage according to claim 1 is characterized in that: In step S4, the crane PLC controller (11) controls the second crane grab bucket (5) to release the hourly salt grabbing amount according to the following formula: The amount of salt required per hour M=0.47*total current of chlor-alkali electrolysis I, where M is in tons and I is in KA.

8. The method for automatically unloading and adding salt in a salt storage according to claim 1, characterized in that: In the step S5, when the no-load current of the accumulator crusher (6) rises from 24A to 26A, the conveying equipment PLC controller (12) starts the vibrating feeder (7) and the scraper (8) in sequence; when the current of the accumulator crusher (6) drops to 24A, the conveying equipment PLC controller (12) stops the scraper (8) and the vibrating feeder (7) in sequence.

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