Continuous crystallization and separation system for DMPT phagostimulant

Abstract

The utility model discloses a DMPT phagostimulant continuous crystallization separation system which comprises a storage tank, the storage tank comprises a methanol tank and a concentrated solution tank, a first discharge pipe is arranged at the bottom of the methanol tank, and a first bottom valve is arranged on the first discharge pipe; a second discharging pipe is arranged at the bottom of the concentrated solution tank; a second bottom valve is arranged on the second discharging pipe; the first discharging pipe and the second discharging pipe are both communicated with a mixing unit; the crystallization unit is communicated with the outlet end of the mixing unit through a connecting pipe; and the separation unit is communicated with the outlet end of the crystallization unit through a crystal paddle pump. The continuous crystallization and separation device system solves the problems that in the prior art, the crystallization process is tedious in technology, long in crystallization time, many in three wastes and discontinuous in production process, the mixing unit, the crystallization unit and the separation unit are arranged and communicated, namely mixing, crystallization and separation are connected in series, and therefore the continuous crystallization and separation device system is formed. The continuity of the production process is ensured, and the crystallization time is shortened.

Description

Technical Field

[0001] The utility model relates to the technical field of production processes of attractants, and particularly relates to a continuous crystallization separation system for DMPT attractant. Background Art

[0002] Animal attractants for promoting growth have various functions and effects. Taking aquatic animal attractants as an example, on the one hand, they can stimulate the sensory organs of fish and shrimps through their own special odors or covering the bad odors in the feed, promoting the feeding of fish and shrimps, and thus accelerating growth; on the other hand, they can accelerate the feeding speed of aquatic animals, shorten the feeding time, effectively reduce feed loss, reduce feed residues in the water body, improve feed utilization rate, and reduce secondary pollution of the water body caused by excess feed.

[0003] With the wide use of attractants, the traditional method of extracting attractants from seaweeds can no longer meet the requirements. Therefore, the artificial synthesis of DMPT has become an inevitable trend. At present, the synthesis process of DMPT is mainly chemical synthesis.

[0004] After consulting the relevant literature on attractants, currently in chemical synthesis literature, DMPT (dimethyl-β-propiothetin) is synthesized from dimethyl sulfide and 3-bromopropionic acid as raw materials. The crude product is washed with cold anhydrous ether and then recrystallized with methanol and filtered to obtain attractant crystals. The existing literature reports that the production processes of attractants all have problems such as cumbersome crystallization processes, long crystallization times, a large amount of three wastes (waste water, waste gas, and waste residue), and discontinuous production processes. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is the cumbersome crystallization process, long crystallization time, a large amount of three wastes, and discontinuous production process. The purpose is to provide a continuous crystallization separation system for DMPT attractant to solve the problems of cumbersome crystallization process, long crystallization time, a large amount of three wastes, and discontinuous production process existing in the prior art.

[0006] The utility model is realized by the following technical solutions:

[0007] A continuous crystallization separation system for DMPT attractant, comprising

[0008] Storage tanks, the storage tanks include a methanol tank and a concentrated liquid tank. A first discharge pipe is arranged at the bottom of the methanol tank, and a first bottom valve is arranged on the first discharge pipe; a second discharge pipe is arranged at the bottom of the concentrated liquid tank, and a second bottom valve is arranged on the second discharge pipe; both the first discharge pipe and the second discharge pipe are communicated with a mixing unit;

[0009] A crystallization unit, the crystallization unit is communicated with the outlet end of the mixing unit through a connecting pipe;

[0010] A separation unit, which is communicated with the outlet end of the crystallization unit through a crystal slurry pump.

[0011] Further optimization: The mixing unit is a Venturi mixer communicated with the first discharge pipe and the second discharge pipe.

[0012] Further optimization: For pre-cooling methanol, it is set that a condenser is also communicated between the methanol tank and the Venturi mixer and is arranged on the first discharge pipe.

[0013] Further optimization: For measuring the temperature of methanol entering the mixing unit to facilitate adjusting the operation of the condenser, it is set that a methanol thermometer is also arranged on the first discharge pipe and is located below the condenser.

[0014] Further optimization: The crystallization unit is a shell-and-tube crystallizer communicated with the Venturi mixer, and the outlet end of the shell-and-tube crystallizer is communicated with the separation unit.

[0015] Further optimization: To avoid crystal sedimentation, it is set that a static mixer for agitating and dispersing crystals and methanol is installed inside the shell-and-tube crystallizer.

[0016] Further optimization: A refrigerant inlet valve and a refrigerant outlet valve are arranged on the shell-and-tube crystallizer.

[0017] Further optimization: The shell-and-tube crystallizer is connected with the crystal slurry pump through a feeding pipe, and a crystallization thermometer is arranged on the feeding pipe and is close to the outlet end of the shell-and-tube crystallizer.

[0018] Further optimization: The separation unit is a crystal separator communicated with the shell-and-tube crystallizer.

[0019] Further optimization: A jet pump is communicated between the concentrated liquid tank and the Venturi mixer and is arranged on the second discharge pipe.

[0020] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0021] 1. By setting a mixing unit, a crystallization unit and a separation unit and connecting the three, that is, connecting mixing, crystallization and separation in series to form a continuous crystallization separation device system, the continuity of the production process is ensured and the crystallization time is shortened.

[0022] 2. The operation of this device is simple and the labor intensity is low, so as to solve the problem of the cumbersome process in the existing crystallization process.

[0023] 3. Only one solvent, methanol, is used in this device and the solvent can be recycled, thus reducing the discharge of three wastes. Description of the Drawings

[0024] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present utility model, form a part of this application, and do not limit the embodiments of the present utility model. In the drawings:

[0025] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0026] Markings in the drawings and corresponding component names:

[0027] 1 - Concentrate tank, 2 - Second bottom valve, 3 - Ejector pump, 4 - Methanol tank, 5 - First bottom valve, 6 - Condenser, 7 - Methanol thermometer, 8 - Venturi mixer, 9 - Shell and tube crystallizer, 10 - Static mixer, 11 - Refrigerant inlet valve, 12 - Refrigerant outlet valve, 13 - Crystallization thermometer, 14 - Crystal slurry pump, 15 - Crystal separator, 16 - Feed pipe, 17 - First discharge pipe, 18 - Second discharge pipe. Specific embodiments

[0028] To make the objectives, technical solutions, and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in conjunction with the embodiments and the accompanying drawings. The illustrative embodiments of the present utility model and their descriptions are only used to explain the present utility model and do not limit the present utility model.

[0029] Embodiment 1 of the present invention provides a continuous crystallization separation system for DMPT attractant, as Figure 1 shown, including:

[0030] Storage tanks, the storage tanks include a methanol tank 4 and a concentrate tank 1. A first discharge pipe 17 is provided at the bottom of the methanol tank 4, and a first bottom valve 5 is provided on the first discharge pipe 17; a second discharge pipe 18 is provided at the bottom of the concentrate tank 1, and a second bottom valve 2 is provided on the second discharge pipe 18; both the first discharge pipe 17 and the second discharge pipe 18 are connected to a mixing unit;

[0031] Crystallization unit, the crystallization unit is connected to the outlet end of the mixing unit through a connecting pipe;

[0032] Separation unit, the separation unit is connected to the outlet end of the crystallization unit through a crystal slurry pump 14.

[0033] Existing literature reports that the production processes of attractants all have problems such as cumbersome crystallization processes, long crystallization times, a large amount of three wastes (waste water, waste gas, and waste residue), and discontinuous production processes.

[0034] In this embodiment, a continuous crystallization separation device system is formed by sequentially performing operations of mixing, crystallization, and separation, ensuring the continuity of the production process and shortening the crystallization time.

[0035] Specifically, the working process of this embodiment is as follows:

[0036] The methanol tank 4 stores the solvent methanol, and the concentrated liquid tank 1 stores the raw materials for synthesizing DMPT. After opening the first bottom valve 5 and the second bottom valve 2, methanol enters the mixing unit through the first discharge pipe 17, and the raw materials for synthesizing DMPT enter the mixing unit through the second discharge pipe 18 for mixing.

[0037] Then it enters the crystallization unit for continuous crystallization. The slurry after crystallization is pumped into the separation unit after being pressurized by the crystal slurry pump, and then the subsequent recovery and drying processes are carried out.

[0038] In this process, only methanol solvent is used in this device and the solvent can be recycled, reducing the emission of three wastes.

[0039] Furthermore, the mixing unit is a Venturi mixer 8 communicated with the first discharge pipe 17 and the second discharge pipe 18. Through the setting of the Venturi mixer 8, the raw materials of DMPT and methanol can be fully and evenly mixed.

[0040] In addition, for pre-cooling the methanol, it is set that: a condenser 6 is also communicated between the methanol tank 4 and the Venturi mixer 8 and is arranged on the first discharge pipe 17.

[0041] Furthermore, a jet pump 3 is communicated between the concentrated liquid tank 1 and the Venturi mixer 8 and is located on the second discharge pipe 18. The jet pump 3 is used to transport various liquids, so as to ensure that the raw materials in the concentrated liquid tank 1 can enter the Venturi mixer 8 stably and safely after passing through the jet pump 3.

[0042] According to another embodiment of the present utility model, the crystallization unit is a shell-and-tube crystallizer 9 communicated with the Venturi mixer 8, and the outlet end of the shell-and-tube crystallizer 9 is communicated with the separation unit.

[0043] In addition, to avoid crystal sedimentation, it is set that: a static mixer 10 for agitating and dispersing crystals and methanol is installed inside the shell-and-tube crystallizer 9. The crystallization time in the shell-and-tube crystallizer 9 is realized by adjusting the opening degrees of the first bottom valve 5 and the second bottom valve 2 and the power of the jet pump 3.

[0044] Furthermore, to measure the temperature of the methanol entering the mixing unit after condensation for facilitating the adjustment of the operation of the condenser 6, it is set that: a methanol thermometer 7 is also arranged on the first discharge pipe 17 and is located below the condenser 6.

[0045] Furthermore, a refrigerant inlet valve 11 and a refrigerant outlet valve 12 are arranged on the shell-and-tube crystallizer 9. Before the crystallization process, it is necessary to pre-cool the shell-and-tube crystallizer 9, so heat exchange can be carried out by entering the refrigerant through the refrigerant inlet valve 11 and discharging the refrigerant through the refrigerant outlet valve 12.

[0046] Further, a feed pipe 16 is connected between the tubular crystallizer 9 and the crystal slurry pump 14, and a crystallization thermometer 13 is provided on the feed pipe 16 near the outlet end of the tubular crystallizer 9. The crystallization thermometer 13 is used to monitor and feedback the crystallization temperature, and adjust the opening degree of the refrigerant inlet valve 11 through feedback to meet the crystallization temperature requirements of process control.

[0047] Further, the separation unit is a crystal separator 15 communicated with the tubular crystallizer 9. The crystal separator 15 separates the methanol and the crystals from the solid-liquid mixture. Then, the methanol mother liquor leaves from the top of the crystal separator 15 and enters the subsequent recovery process for recycling. The DMPT crystals leave from the bottom of the crystal separator 15 and enter the drying process to be dried to obtain the product.

[0048] The specific working process of the present utility model is as follows:

[0049] 1. Open the second bottom valve 2 of the concentrated liquid tank 1 and the first bottom valve 5 of the methanol tank 4.

[0050] 2. Then open the refrigerant inlet valve 11 and the refrigerant outlet valve 12 of the tubular crystallizer 9 to pre-cool the tubular crystallizer 9.

[0051] 3. Start the crystal slurry pump and the ejector pump 3 in sequence. After the methanol in the methanol tank 4 is pre-cooled by the condenser 6, it is mixed with the DMPT concentrated liquid in the concentrated liquid tank 1 through the ejector pump 3 and is fully and evenly mixed in the Venturi mixer 8. The mixed feed liquid enters the tubular crystallizer 9 for continuous crystallization.

[0052] A static mixer 10 is installed inside the tube of the tubular crystallizer 9 to enable the precipitated crystals and methanol to be well dispersed and evenly flow inside the tube, preventing crystal settlement.

[0053] The crystallization time inside the tubular crystallizer 9 is controlled by adjusting the opening degrees of the first bottom valve 5 and the second bottom valve 2 and the power of the ejector pump 3. The heat generated by crystallization inside the tubular crystallizer 9 is exchanged through the refrigerant. The crystallization temperature is fed back through the crystallization thermometer 13 installed at the outlet end of the tubular crystallizer 9, thereby adjusting the opening degree of the refrigerant inlet valve 11 to meet the crystallization temperature requirements of process control.

[0054] 4. The slurry after crystallization is pumped into the crystal separator 15 by the crystal slurry pump 14 under pressure for solid-liquid separation of the DMPT crystals and the methanol mother liquor. Then, the methanol mother liquor leaves from the top of the crystal separator 15 and enters the subsequent recovery process for recycling. The DMPT crystals leave from the bottom of the crystal separator 15 and enter the drying process to be dried to obtain the product.

[0055] The specific embodiments described above have further elaborated in detail the purpose, technical solutions and beneficial effects of the present utility model. It should be understood that the above description is only the specific embodiments of the present utility model and is not used to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A DMPT attractant continuous crystallization separation system, characterized in that: include: A storage tank, wherein the storage tank comprises a methanol tank and a concentrated liquid tank, wherein a first discharge pipe is provided at the bottom of the methanol tank, and a first bottom valve is provided on the first discharge pipe; a second discharge pipe is provided at the bottom of the concentrated liquid tank, and a second bottom valve is provided on the second discharge pipe; the first discharge pipe and the second discharge pipe are both connected to a mixing unit; A crystallization unit, wherein the crystallization unit is connected to the outlet end of the mixing unit through a connecting pipe; The separation unit is connected with the outlet of the crystallization unit through a crystal propeller pump.

2. The DMPT food attractant continuous crystallization separation system according to claim 1, characterized in that: The mixing unit is a venturi mixer connected to the first discharge pipe and the second discharge pipe.

3. The DMPT food attractant continuous crystallization separation system according to claim 2, characterized in that: A condenser arranged on the first discharge pipe is also connected between the methanol tank and the venturi mixer.

4. The DMPT food attractant continuous crystallization separation system according to claim 3, characterized in that: The first discharge pipe is also provided with a methanol thermometer located below the condenser.

5. The DMPT food attractant continuous crystallization separation system according to claim 2, characterized in that: The crystallization unit is a tube-in-tube crystallizer connected to a venturi mixer, and the outlet end of the tube-in-tube crystallizer is connected to a separation unit.

6. The DMPT food attractant continuous crystallization separation system according to claim 5, characterized in that: A static mixer for stirring and dispersing crystals and methanol is installed inside the shell-and-tube crystallizer.

7. The DMPT food attractant continuous crystallization separation system according to claim 5, characterized in that: The shell-and-tube crystallizer is provided with a refrigerant inlet valve and a refrigerant outlet valve.

8. The DMPT food attractant continuous crystallization separation system according to claim 5, characterized in that: The shell-and-tube crystallizer is connected to the crystal paddle pump via a feeding pipe, and a crystallization thermometer close to the outlet end of the shell-and-tube crystallizer is arranged on the feeding pipe.

9. The DMPT food attractant continuous crystallization separation system according to claim 1, characterized in that: The separation unit is a crystal separator connected to the shell-and-tube crystallizer.

10. The DMPT food attractant continuous crystallization separation system according to claim 2, characterized in that: A jet pump located on the second discharge pipe is connected between the concentrate tank and the venturi mixer.

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