A calcium formate crude product crystallization system

Abstract

This invention discloses a crude calcium formate crystallization system, relating to the field of chemical inorganic salt preparation technology. It includes several reaction vessels, a transfer tank, a purification system, a centrifuge, a concentration system, and a high-level tank. The reaction vessels, transfer tank, centrifuge, filter, and high-level tank are interconnected. Each reaction vessel has a first overflow hole at the top of its side wall. Each reaction vessel is connected to a calcium carbonate supply device and a formic acid supply device. The concentration system includes an evaporation device, a hot air distributor, and a hot air furnace. The purification system includes an overflow tank and a filter press. Each overflow tank has a second overflow hole at the top of its side wall. Each first overflow hole is connected to the overflow tank via an overflow pipe, and each overflow pipe is equipped with an overflow valve. The second overflow hole is connected to the filter press via a pipeline, and the filter press is connected to the evaporation device. The overflow tank is connected to the transfer tank, and a movable sealing plate is provided at the bottom outlet of the overflow tank. This invention can solve the problems of difficult impurity separation, resource waste, high energy consumption, and poor crystallization quality in traditional preparation processes.

Description

Technical Field

[0001] This invention relates to the field of chemical inorganic salt preparation technology, specifically to a crude calcium formate crystallization system. Background Technology

[0002] Calcium formate is a versatile organic chemical raw material that can be used as an animal feed additive, as an additive in concrete and mortar, or as a preservative in leather tanning.

[0003] Patent publication number CN107686446A discloses a method for preparing feed-grade calcium formate. The present invention's method for preparing feed-grade calcium formate includes the following steps: A. Inject water and / or mother liquor into the reaction vessel; B. Add 190-210 kg of light calcium carbonate and / or nano calcium carbonate to each cubic meter of water and / or mother liquor, stir evenly, and then slowly add 210-230 kg of formic acid solution with a mass concentration of ≥88% to each cubic meter of water or mother liquor. C. The calcium formate produced in the reaction crystallizes and precipitates at the bottom of the reaction vessel. Continue stirring for at least 40 minutes at a stirring rate of 40-90 r / min to ensure the reaction proceeds fully. Once the reaction is complete, the reaction product is obtained. D. The reaction products are separated into solid and liquid components to obtain calcium formate solid and mother liquor; E. The calcium formate solid is dried to remove free water, resulting in feed-grade calcium formate product.

[0004] Its disadvantages are that during the preparation process, the reaction mixture often contains floating impurities such as light carbon, which are small, black, and suspended impurities that are not efficiently separated, thus affecting the purity of the product; the centrifuged liquid is not recycled, and a large amount of effective components are discharged with the waste liquid, resulting in resource waste, etc. Summary of the Invention

[0005] The purpose of this invention is to provide a calcium formate crude crystallization system that can efficiently separate floating impurities such as light carbon in reaction mixtures, realize the recycling of centrifugal liquid, improve the overall energy utilization efficiency, effectively purify production exhaust gas, and improve the uniformity of crystallized particles, so as to solve the problems of difficult impurity separation, resource waste, high energy consumption, environmental pollution and poor crystallization quality in traditional preparation processes.

[0006] The technical solution adopted in this invention is as follows.

[0007] A crude calcium formate crystallization system includes several reaction vessels, a transfer tank, a purification system, a centrifuge, a concentration system, and a high-level tank.

[0008] Each reactor is connected to the transfer tank via pipelines. The transfer tank is connected to the centrifuge inlet via pipelines. The centrifuge outlet, filter, and high-level tank are connected via pipelines. Each reactor is connected to the high-level tank via pipelines.

[0009] Each reactor has a first overflow hole located at a certain height below the top of the side wall; each reactor is connected to a calcium carbonate supply device and a formic acid supply device.

[0010] The concentration system includes an evaporation device, a hot air distributor, and a hot air furnace. The evaporation device is equipped with a heat exchange coil, one end of which is connected to the hot air furnace, and the other end is connected to the hot air distributor via a hot air pipe. Each reactor is equipped with a reactor heating pipe, and the high-level tank is equipped with a centrifugal liquid heating pipe. Each reactor heating pipe and centrifugal liquid heating pipe is connected to the hot air distributor via a hot air pipe. The evaporation device is connected to the high-level tank via a pipeline. The top of the evaporation device and the top of each reactor are connected to the absorption tower via exhaust pipes. The impurity removal system includes a cylindrical overflow tank and a filter press. Each overflow tank has a second overflow hole at a certain height below the top of its side wall. The top of the overflow tank is lower than each first overflow hole. Each first overflow hole is connected to the overflow tank via an overflow pipe, and each overflow pipe is equipped with an overflow valve. The second overflow hole is connected to the filter press via a pipeline, and the outlet of the filter press is connected to the evaporation device via a pipeline. The bottom of the overflow tank is connected to the top of the transfer tank.

[0011] The working steps are as follows: calcium carbonate raw material and formic acid solution are gradually fed into each reaction vessel through the calcium carbonate supply device and the formic acid supply device, respectively. The two react fully in the reaction vessel for a period of time to generate a calcium formate mixture, and the liquid level of the calcium formate mixture reaches above the first overflow hole. At this time, light carbon floats on the surface of the mixture. The overflow valve is opened, and the calcium formate mixture containing light carbon impurities flows into the overflow tank through the first overflow hole. When the liquid level of the mixture in the overflow tank is higher than the second overflow hole, the light carbon impurities accumulate at the top of the mixture in the overflow tank and enter the filter press for deep impurity removal through the second overflow hole. The filtered clear liquid is sent to the evaporator for evaporation. The movable sealing plate is opened, and the mixture in the overflow tank enters the turnover tank through the bottom pipe of the overflow tank.

[0012] The mixtures from the reaction vessels are transferred to a transfer tank, and then the mixtures in the transfer tank are sent to a centrifuge. The solid calcium formate crystals separated by centrifugation can be dried. The centrifuged liquid is discharged into a filter to filter out reaction impurities, and then flows into a high-level tank.

[0013] Part of the centrifuged liquid in the high-level tank is returned to each reaction vessel to continue participating in the reaction, while the other part is sent to the evaporation device for concentration.

[0014] The hot air generated by the hot air furnace is divided into two paths: one path directly enters the heating tube of the reactor in the evaporator to provide a heat source; the other path enters the heat exchange coil of the evaporation device to heat the centrifugal liquid. The hot air after heat exchange is distributed to the centrifugal liquid heating tube of each reactor by the hot air distributor to provide heat preservation or heating for the reaction. The exhaust gas generated by the evaporation device and the evaporator enters the absorption tower through their respective outlets and is discharged after purification to meet the standards.

[0015] Its beneficial effects are as follows: This system, through the synergy of an overflow tank and a filter press, filters the centrifuged liquid after centrifugation to remove insoluble impurities and reuse the liquid, achieving efficient separation of floating impurities such as light carbon and insoluble impurities in the reaction mixture, effectively improving the purity of crude calcium formate; the cylindrical overflow tank is designed to prevent the mixture from clogging at the bottom of the overflow tank. The reflux and evaporation concentration mechanism of the high-level tank recovers and utilizes the effective components in the centrifuged liquid, reducing resource waste; the hot air generated by the hot air furnace is used for calcium formate reactor production after multi-stage heat exchange and distribution, reducing production energy consumption; the exhaust gas generated by the evaporation device and reactor is purified by an absorption tower before being discharged.

[0016] As a preferred technical solution, the high-level tank is connected to a flushing nozzle installed at the bottom of the overflow tank via a high-pressure pipe; a high-pressure pump is installed on the high-pressure pipe. Since the liquid in the overflow tank is a supersaturated calcium formate solution, it easily crystallizes at the bottom of the overflow tank. High-pressure centrifugal liquid is sprayed onto the flushing nozzle through the high-pressure pipe to further clean the bottom of the overflow tank and prevent blockage.

[0017] As a preferred technical solution, a movable sealing plate is provided at the bottom outlet of the overflow channel. The movable sealing plate is set horizontally.

[0018] As a preferred technical solution, each pipeline is equipped with a liquid pump.

[0019] As a preferred technical solution, the heating tubes of each reactor are connected to the hot air distributor, the centrifugal liquid heating tubes are connected to the hot air distributor, the heat exchange coils are connected to the hot air distributor, and the hot air furnace is connected to the heat exchange coils via hot air pipes. Each hot air pipe is equipped with an airflow control valve. The heat output is adjusted by controlling the airflow through the valves.

[0020] As a preferred technical solution, each reactor is equipped with a first thermometer; a second thermometer is installed on the high-level tank.

[0021] As a preferred technical solution, each reactor is equipped with a first stirrer; a transfer tank is equipped with a second stirrer; the transfer tank is located below each reactor; and the elevated tank is located above each reactor. During production, each stirrer is always operational.

[0022] As a preferred technical solution, each reactor is connected to a calcium carbonate supply device via a calcium carbonate powder screw conveyor, and each reactor is connected to a formic acid supply device via a formic acid pipe, which is equipped with a drip pump. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a preferred embodiment of the calcium formate crude crystallization system of the present invention.

[0024] Figure 2 yes Figure 1 A magnified view of part A.

[0025] Figure 3 yes Figure 2 A magnified view of part C.

[0026] Figure 4 yes Figure 2 A magnified view of part D.

[0027] Figure 5 yes Figure 1 A magnified view of part B.

[0028] Figure 6 yes Figure 5 A magnified view of part E.

[0029] Figure 7 yes Figure 5 A magnified view of part C.

[0030] Figure 8 yes Figure 5 A magnified view of part F.

[0031] Wherein: reactor-1; first overflow hole-11; calcium carbonate supply device-12; formic acid supply device-13; reactor heating tube-14; reactor heating tube air inlet-141; reactor heating tube air outlet-142; First thermometer-15; First stirrer-16; Calcium carbonate powder screw conveyor-17; Formic acid tube-18; Drop pump-19. Transfer tank-2; Second thermometer-21; Second stirrer-22; Overflow trough-3; Filter press-30; Second overflow hole-31; Overflow pipe-32; Overflow valve-33; Movable sealing plate-34; Flushing nozzle-35; Centrifuge-4; Filter-41; Evaporation unit-5; Hot air distributor-51; Hot air furnace-52; Heat exchange coil-53; Heat exchange coil air inlet-531; Heat exchange coil air outlet-532; First hot air duct - 54; Second hot air duct - 55; Second air volume control valve - 56; First air volume control valve - 57; Third hot air duct - 58; Third air volume control valve - 59; High-level tank - 6; Centrifugal liquid heating tube - 61; Centrifugal liquid heating tube air inlet - 611; Centrifugal liquid heating tube air outlet - 612 Absorption Tower-7; First pipe - 81; Second pipe - 82; Third pipe - 83; Fourth pipe - 84; High-pressure pipe - 85; First exhaust pipe - 86; Second exhaust pipe - 87; Fifth pipe - 88; Sixth pipe - 89; Seventh pipe - 810; First pump - 91; Second pump - 92; Third pump - 93; Fourth pump - 94; High-pressure pump - 95; Fifth pump - 96; Sixth pump - 97; Seventh pump - 98. Detailed Implementation

[0032] The present invention will now be further described in conjunction with the accompanying drawings and embodiments.

[0033] Example 1. As... Figure 1-8 As shown, a crude calcium formate crystallization system includes two reaction vessels 1, a transfer tank 2, a purification system, a centrifuge 4, a concentration system, and a high-level tank 6. In another example, the crude calcium formate crystallization system includes three or more reaction vessels 1.

[0034] Each reactor 1 is connected to the transfer tank 2 via a pipeline. The transfer tank 2 is connected to the inlet of the centrifuge 4 via a pipeline. The outlet of the centrifuge 4, the filter 41, and the high-level tank 6 are connected via pipelines. Each reactor 1 is connected to the high-level tank 6 via a pipeline.

[0035] like Figure 5-7 As shown, each reactor 1 has a first overflow hole 11 located at a certain height below the top of its side wall; each reactor 1 is connected to a calcium carbonate supply device 12 and a formic acid supply device 13. Specifically, the distance between the first overflow hole 11 and the top of the reactor 1 is 5 cm.

[0036] The concentration system includes an evaporation unit 5, a hot air distributor 51, and a hot air furnace 52. For example... Figure 3 As shown, the evaporation device 5 is equipped with a heat exchange coil 53.

[0037] The air inlet of the heat exchange coil 53 is connected to the hot air furnace 52, and the air outlet of the heat exchange coil 53 is connected to the hot air distributor 51 through a hot air pipe.

[0038] like Figure 6-7 As shown, each reactor 1 is equipped with a reactor heating pipe 14. (As indicated...) Figure 4 As shown, the high-level tank 6 is equipped with a centrifugal liquid heating tube 61.

[0039] Each reactor heating tube 14 and centrifugal liquid heating tube 61 is connected to the hot air distributor 51 via a hot air pipe; the evaporation device 5 is connected to the high-level tank 6 via a pipeline.

[0040] The top of the evaporation device 5, the top of each reaction vessel, and the absorption tower 7 are all connected by exhaust pipes.

[0041] like Figure 7 As shown, the high-level tank 6 is connected to the flushing nozzle 35 installed at the bottom of the overflow tank 3 via a high-pressure pipe 85; a high-pressure pump 95 is installed on the high-pressure pipe 85.

[0042] The impurity removal system includes a cylindrical overflow trough 3 and a filter press 30. For example... Figure 7 As shown, a second overflow hole 31 is provided at a certain height below the top of the side wall of each overflow tank 3, and the top of the overflow tank 3 is lower than the first overflow hole 11. Each first overflow hole 11 is connected to the overflow tank 3 through an overflow pipe 32. Each overflow pipe 32 is provided with an overflow valve 33. The second overflow hole 31 is connected to the filter press 30 through a pipeline, and the outlet of the filter press 30 is connected to the evaporation device 5 through a pipeline; the bottom end of the overflow tank 3 is connected to the top of the turnover tank 2, and a movable sealing plate 34 is provided horizontally at the bottom outlet of the overflow tank 3.

[0043] The working steps are as follows: Calcium carbonate raw material and formic acid solution are gradually fed into each reaction vessel 1 through the calcium carbonate supply device 12 and the formic acid supply device 13, respectively. The two react fully in the reaction vessel 1 for a period of time to generate a calcium formate mixture, and the liquid level of the calcium formate mixture reaches above the first overflow hole 11. At this time, light carbon floats on the surface of the mixture. The overflow valve 33 is opened, and the calcium formate mixture containing light carbon impurities flows into the overflow tank 3 through the first overflow hole 11. When the liquid level of the mixture in the overflow tank 3 is higher than the second overflow hole 31, the light carbon impurities accumulate at the top of the mixture in the overflow tank 3 and enter the filter press 30 through the second overflow hole 31 for deep impurity removal. The filtered clear liquid is transported to the evaporator 5 for evaporation. The movable sealing plate 34 is opened, and the mixture in the overflow tank 3 enters the transfer tank 2 through the bottom pipe of the overflow tank 3. During the dropwise addition reaction, the weight ratio of calcium carbonate to formic acid is 1:0.83, the reaction dimension is 60 degrees Celsius, and the stirring speed is 60 r / min. After the dropwise addition reaction is complete, allow the reaction system to continue reacting for 15–60 minutes. This process helps the crystals grow fully, forming uniform, free-flowing, "flowing sand"-like calcium formate crystals.

[0044] The mixtures that have completed the reaction in each reactor 1 are sent to the transfer tank 2. The mixtures in the transfer tank 2 are sent to the centrifuge 4. The solid calcium formate crystals separated by centrifugation can be dried. The centrifuged liquid is discharged into the filter 41 to filter out reaction impurities, and then flows into the high-level tank 6. The stirring speed is 60 r / min.

[0045] Part of the centrifuged liquid in the high-level tank 6 is returned to each reaction vessel 1 to continue participating in the reaction, and the other part is sent to the evaporation device 5 for concentration.

[0046] The hot air generated by the hot air furnace 52 is divided into two paths: one path directly enters the reactor heating tube 14 of the evaporator 5 to provide a heat source; the other path enters the heat exchange coil 53 of the evaporation device 5 to heat the centrifugal liquid. The hot air after heat exchange is distributed to the centrifugal liquid heating tube 61 of each reactor 1 by the hot air distributor 51 to provide heat preservation or heating for the reaction. The tail gas generated by the evaporation device 5 and the evaporator 5 enters the absorption tower 7 through their respective outlets and is discharged after purification to meet the standards.

[0047] The beneficial effects of claim 1 are: This system, through the synergy of an overflow tank and a filter press, filters the centrifuged liquid after centrifugation to remove insoluble impurities and reuse the liquid, achieving efficient separation of floating impurities such as light carbon and insoluble impurities in the reaction mixture, effectively improving the purity of crude calcium formate. The cylindrical overflow tank 3 prevents the mixture in the overflow tank 3 from clogging at the bottom. High-pressure centrifuged liquid is sprayed into the flushing nozzle 35 through the high-pressure pipe 85, which can further clean the bottom of the overflow tank and prevent clogging. The reflux and evaporation concentration mechanism of the high-level tank recovers and utilizes the effective components in the centrifuged liquid, reducing resource waste. The hot air generated by the hot air furnace is used for calcium formate reactor production after multi-stage heat exchange and distribution, reducing production energy consumption. The exhaust gas generated by the evaporation device and the reactor is purified by an absorption tower before being discharged.

[0048] Each pipeline is equipped with a liquid pump. For example... Figure 6-7 As shown, the bottom of each reactor 1 is connected to the top of the transfer tank 2 through the first pipeline 81, and each first pipeline 81 is equipped with a first liquid pump 91.

[0049] like Figure 5 As shown, the bottom end of the transfer tank 2 is connected to the centrifuge 4 through the second pipeline 82, and the second pipeline 82 is equipped with a second liquid pump 92.

[0050] like Figure 1 As shown, the outlet of centrifuge 4 is connected to filter 41 through third pipeline 83, and third pump 93 is provided on third pipeline 83.

[0051] like Figure 1 , Figure 5 As shown, the top of each reactor 1 is connected to the bottom of the centrifugal liquid storage tank 6 via a fourth pipeline 84, and a fourth pump 94 is provided on each fourth pipeline 84.

[0052] like Figure 5 , Figure 8 As shown, the second overflow hole 31 is connected to the filter press 30 through the fifth pipeline 88, and the fifth pipeline 88 is equipped with a fifth liquid pump 96.

[0053] like Figure 1 , Figure 2As shown, the outlet of the filter press 30 is connected to the evaporator 5 through the sixth pipeline 89, and the sixth pipeline 89 is equipped with a sixth liquid pump 97.

[0054] like Figure 2 , Figure 4 As shown, the centrifugal liquid storage tank 6 is connected to the evaporation kettle 5 through the seventh pipeline 810, and the seventh pipeline 810 is equipped with a seventh liquid pump 98.

[0055] like Figure 1 , Figure 2 As shown, the outlet of filter 41 is connected to centrifugal liquid storage tank 6 through the eighth pipeline 811, and the eighth pump 99 is provided on the eighth pipeline 811.

[0056] like Figure 1 As shown, the evaporator 5 is connected to the absorption tower 7 via the first exhaust pipe 86; each evaporator 5 is connected to the absorption tower 7 via the second exhaust pipe 87. The movable sealing plate 34 is horizontally arranged.

[0057] Each reactor heating tube 14 is connected to the hot air distributor 51, the centrifugal liquid heating tube 61 is connected to the hot air distributor 51, the heat exchange coil 53 is connected to the hot air distributor 51, and the hot air furnace 52 is connected to the heat exchange coil 53 via hot air pipes. Each hot air pipe is equipped with an airflow control valve. The heat output is adjusted by controlling the airflow. The outer surface of each hot air pipe is provided with a heat insulation layer.

[0058] Specifically, such as Figure 1 , Figure 2 , Figure 5 As shown, each reactor heating tube 14, centrifugal liquid heating tube 61 and hot air distributor 51 are connected to the first hot air pipe 54 respectively; each first hot air pipe 54 is equipped with a first air volume control valve 57.

[0059] like Figure 2 As shown, the hot air furnace 52 and the heat exchange coil 53 are connected through the second hot air pipe 55; the second hot air pipe 55 is equipped with a second air volume control valve 56.

[0060] like Figure 1 , Figure 2 As shown, the heat exchange coil 53 is connected to the hot air distributor 51 through the third hot air pipe 58, and the third hot air pipe 58 is equipped with a third air volume control valve 59.

[0061] like Figure 4-8As shown, each reactor 1 is equipped with a first thermometer 15; a second thermometer 21 is installed on the elevated tank 6. Each reactor 1 is equipped with a first stirrer 16; a second stirrer 22 is installed in the transfer tank 2. The transfer tank 2 is located below each reactor 1; the elevated tank 6 is located above each reactor. During production, each stirrer is always operational. Each reactor 1 is connected to a calcium carbonate supply device 12 via a calcium carbonate powder screw conveyor 17, and each reactor 1 is connected to a formic acid supply device 13 via a formic acid pipe 18, on which a drip pump 19 is installed.

Claims

1. A system for crystallizing crude calcium formate, characterized in that: It includes several reaction vessels, transfer tanks, impurity removal systems, centrifuges, concentration systems, and high-level tanks; Each reactor is connected to the transfer tank via pipelines. The transfer tank is connected to the centrifuge inlet via pipelines. The centrifuge outlet, filter, and high-level tank are connected via pipelines. Each reactor is connected to the high-level tank via pipelines. Each reactor has a first overflow hole at a certain height below the top of its side wall. Each reactor is connected to a calcium carbonate supply device and a formic acid supply device. The concentration system includes an evaporation device, a hot air distributor, and a hot air furnace. The evaporation device is equipped with a heat exchange coil, one end of which is connected to the hot air furnace, and the other end is connected to the hot air distributor via a hot air pipe. Each reactor is equipped with a reactor heating pipe, and the high-level tank is equipped with a centrifugal liquid heating pipe. Each reactor heating pipe and centrifugal liquid heating pipe is connected to the hot air distributor via a hot air pipe. The evaporation device is connected to the high-level tank via a pipeline. The top of the evaporation device and the top of each reactor are connected to the absorption tower via exhaust pipes. The impurity removal system includes a cylindrical overflow tank and a filter press. Each overflow tank has a second overflow hole at a certain height below the top of its side wall. The top of the overflow tank is lower than each first overflow hole. Each first overflow hole is connected to the overflow tank via an overflow pipe, and each overflow pipe is equipped with an overflow valve. The second overflow hole is connected to the filter press via a pipeline, and the outlet of the filter press is connected to the evaporation device via a pipeline. The bottom of the overflow tank is connected to the top of the transfer tank.

2. The calcium formate crude crystallization system as described in claim 1, characterized in that: The high-level tank is connected to the flushing nozzles installed at the bottom of the overflow tank via a high-pressure pipe; a high-pressure pump is installed on the high-pressure pipe.

3. The calcium formate crude crystallization system as described in claim 1, characterized in that: The overflow trough has a movable sealing plate at the bottom outlet.

4. The calcium formate crude crystallization system as described in claim 1, characterized in that: Each pipeline is equipped with a liquid pump.

5. The crude calcium formate crystallization system as described in claim 1, characterized in that: Each reactor heating tube is connected to the hot air distributor, the centrifugal liquid heating tube to the hot air distributor, the heat exchange coil to the hot air distributor, and the hot air furnace to the heat exchange coil via hot air pipes. Each hot air pipe is equipped with an air volume control valve.

6. The calcium formate crude crystallization system as described in claim 1, characterized in that: Each reactor is equipped with a first thermometer; a second thermometer is installed on the high-level tank.

7. The calcium formate crude crystallization system as described in claim 1, characterized in that: Each reactor is equipped with a first stirrer; a transfer tank is equipped with a second stirrer; the transfer tank is located below each reactor; and the high-level tank is located above each reactor.

8. The calcium formate crude crystallization system as described in claim 1, characterized in that: Each reactor is connected to a calcium carbonate supply device via a calcium carbonate powder screw conveyor, and each reactor is connected to a formic acid supply device via a formic acid pipe, which is equipped with a drip pump.

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