Crystallizer for oxalic acid crystallization

Abstract

The utility model relates to the technical field of chemical equipment, in particular to a crystallizer for oxalic acid crystallization. According to the utility model, the plurality of layers of annular evaporation areas and the bottom evaporation area are arranged in the crystallizer shell with the columnar structure, and the air inlets are formed in each layer of annular evaporation area and the bottom evaporation area, so that the evaporation surface is obviously enlarged, the flowability of water vapor on the evaporation surface is enhanced, the evaporation crystallization speed is accelerated, and the production efficiency is improved; the volume of the annular evaporation area and the volume of the bottom evaporation area are small, the retention time of a saturated oxalic acid solution is short, the phenomena of crystal agglomeration and non-uniform distribution can be effectively avoided, and the product quality of oxalic acid crystals can be improved.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically to a crystallizer for oxalic acid crystallization. Background Technology

[0002] Oxalic acid is an important organic chemical raw material widely used in pharmaceuticals, dyes, coatings, and other fields. Crystallization is a crucial step in oxalic acid production. Currently, existing oxalic acid crystallizers suffer from a small evaporation area, resulting in low evaporation and crystallization efficiency, thus affecting production progress. Furthermore, improper operation can cause oxalic acid crystal agglomeration and uneven distribution, consequently impacting product quality. Therefore, it is necessary to design an oxalic acid crystallizer that can effectively increase the evaporation surface area, improve crystallization efficiency, and simultaneously prevent crystal agglomeration and uneven distribution, thereby enhancing product quality. Utility Model Content

[0003] The purpose of this invention is to provide a crystallizer for oxalic acid crystallization. By setting multiple evaporation surfaces inside the crystallizer and increasing the fluidity of water vapor on the evaporation surfaces, the evaporation effect is enhanced, thereby improving the evaporation and crystallization efficiency of oxalic acid solution.

[0004] The technical solution of this utility model is as follows: The crystallizer for oxalic acid crystallization includes a crystallizer shell with a columnar structure. The top and bottom of the shell are semi-elliptical, semi-circular, or conical structures. Multiple layers of liquid containment devices are provided inside the shell. The lower end of each layer of liquid containment devices is connected to the inner wall of the shell. The liquid containment devices and the inner wall of the shell form an annular evaporation zone. The bottom space inside the crystallizer constitutes a bottom evaporation zone. An exhaust port is provided at the top of the shell. Crystallization outlets are provided on the bottom of the crystallizer shell at the bottom of each annular evaporation zone and at the bottom of the crystallizer shell. Oxalic acid inlets are provided in each annular evaporation zone and the bottom evaporation zone. The oxalic acid inlets are located on the crystallizer shell.

[0005] Furthermore, a crystallization outlet for the annular evaporation zone is provided on the crystallizer shell opposite the oxalic acid inlet of the annular evaporation zone.

[0006] Furthermore, one or more air inlets are provided on the crystallizer shell above each annular evaporation zone.

[0007] Furthermore, the bottom of the annular evaporation zone slopes from the oxalic acid inlet to the crystallization outlet.

[0008] Furthermore, one or more temperature detection ports are provided on the crystallizer shell of each annular evaporation zone.

[0009] Furthermore, a baffle is installed in the annular evaporation zone. The baffle is connected to the crystallizer shell and the liquid containment device. An oxalic acid inlet is provided on one side of the baffle, and a crystallization outlet is provided on the other side of the baffle. Beneficial effects

[0010] 1. This utility model significantly increases the evaporation surface by setting up multiple annular evaporation zones, allowing oxalic acid solution to evaporate over a larger area; at the same time, air inlets are set up in each annular evaporation zone to increase the flow of water vapor on the evaporation surface, thereby accelerating the evaporation and crystallization speed and improving production efficiency.

[0011] 2. The small volume of each annular evaporation zone in this invention results in a short residence time for the saturated oxalic acid solution, effectively preventing crystal agglomeration and uneven distribution, and improving the product quality of oxalic acid crystals. Attached Figure Description

[0012] Figure 1 This is a partial cross-sectional front view of the present invention.

[0013] Figure 2 This is a schematic diagram of the left-side structure of this utility model;

[0014] Figure 3 This is a top view of the structure of this utility model;

[0015] Figure 4 This is a top view of the cross-section of the present invention.

[0016] In the diagram: 1 - shell; 2 - liquid containment device; 3 - crystallization outlet; 4 - oxalic acid inlet; 5 - air inlet; 6 - exhaust port; 7 - partition. Detailed Implementation Example 1

[0017] refer to Figure 1-3In order to improve the crystallization efficiency of oxalic acid crystallizers and avoid the occurrence of oxalic acid crystal agglomeration and uneven distribution, thereby avoiding affecting the quality of oxalic acid products. This utility model provides a crystallizer for oxalic acid crystallization. The crystallizer includes a columnar crystallizer shell 1 with a semi-elliptical structure at the top and bottom. Three layers of liquid containment devices 2 are installed inside the shell 1. The lower end of each layer of liquid containment device 2 is connected to the inner wall of the shell 1. The liquid containment devices 2 and the inner wall of the shell 1 form an annular evaporation zone. The bottom space inside the crystallizer forms a bottom evaporation zone. An exhaust port 6 is provided at the top of the shell 1. A crystallization outlet 3 is provided on the bottom of the crystallizer shell 1 at the bottom of each annular evaporation zone. An oxalic acid inlet 4 is provided in each annular evaporation zone and the bottom evaporation zone. The oxalic acid inlet 4 is located on the crystallizer shell 1. The crystallization outlet 3 of the annular evaporation zone is provided on the crystallizer shell 1 opposite the oxalic acid inlet 4 of the annular evaporation zone. Two air inlets 5 are provided on the crystallizer shell 1 above the annular evaporation zone. The bottom of the annular evaporation zone forms a slope from the oxalic acid inlet 4 to the crystallization outlet 3. Two temperature detection ports are provided on the crystallizer shell 1 of each annular evaporation zone.

[0018] Another embodiment differs from Embodiment 1 in that the top and bottom of the housing 1 are semi-circular structures.

[0019] Another embodiment differs from Embodiment 1 in that the top and bottom of the housing 1 are tapered structures.

[0020] Another embodiment differs from Embodiment 1 in that: two layers of enclosure devices are provided inside the housing 1.

[0021] Another embodiment differs from Embodiment 1 in that: a five-layer enclosure device is provided inside the housing 1.

[0022] Another embodiment differs from Embodiment 1 in that: four air inlets 5 are provided on the crystallizer shell 1 above the annular evaporation zone.

[0023] Another embodiment differs from Embodiment 1 in that: six air inlets 5 are provided on the crystallizer shell 1 above the annular evaporation zone.

[0024] Another embodiment differs from Embodiment 1 in that: (Refer to...) Figure 4 A baffle 7 is installed in the annular evaporation zone. The baffle 7 is connected to the crystallizer shell 1 and the liquid containment device 2. An oxalic acid inlet 4 is provided on one side of the baffle 7, and a crystallization outlet 3 is provided on the other side of the baffle 7.

[0025] The working principle of this invention is as follows: Oxalic acid solution enters each annular evaporation zone within the crystallizer through the oxalic acid inlet 4. Evaporation is achieved through vacuuming. The evaporated water vapor flows upwards through the channel in the middle of the liquid containment device 2 and exits through the exhaust port 6. Simultaneously, air can be introduced through the air inlet 5, or the water vapor extracted by the exhaust device can be dehydrated and returned to the air inlet 5, increasing the flow of water vapor on the evaporation surface of the annular evaporation zone and promoting rapid evaporation and crystallization. As water in the oxalic acid solution continuously evaporates, oxalic acid gradually crystallizes and precipitates. The solution containing oxalic acid crystals flows out from the crystallization outlet 3 and enters the next processing unit. This invention, by setting up multiple annular evaporation zones and air inlets 5, greatly improves the efficiency of oxalic acid crystallization. Furthermore, the relatively small volume of each annular evaporation zone results in a short residence time for the saturated oxalic acid solution, effectively preventing crystal agglomeration and uneven distribution, thus improving the product quality of the oxalic acid crystals.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A crystallizer for oxalic acid crystallization, characterized by: The crystallizer for oxalic acid crystallization includes a columnar crystallizer shell with a semi-elliptical, semi-circular, or conical top and bottom. Multiple layers of liquid containment devices are installed inside the shell, with the lower end of each layer connected to the inner wall of the shell. The liquid containment devices and the inner wall of the shell form an annular evaporation zone. The bottom space inside the crystallizer constitutes a bottom evaporation zone. An exhaust port is provided at the top of the shell. Crystallization outlets are provided on the bottom of each annular evaporation zone and at the bottom of the crystallizer shell. An oxalic acid inlet is provided in each annular evaporation zone and the bottom evaporation zone, and the oxalic acid inlet is located on the crystallizer shell.

2. A crystallizer for oxalic acid crystallization according to claim 1, characterized in that: The crystallization outlet of the annular evaporation zone is set on the crystallizer shell opposite the oxalic acid inlet of the annular evaporation zone.

3. A crystallizer for oxalic acid crystallization according to claim 2, characterized in that: One or more air inlets are provided on the crystallizer shell above each annular evaporation zone.

4. A crystallizer for oxalic acid crystals according to any of claims 1-3, characterized in that: The bottom of the annular evaporation zone slopes from the oxalic acid inlet to the crystallization outlet.

5. A crystallizer for oxalic acid crystallization according to claim 1, characterized in that: One or more temperature detection ports are provided on the crystallizer shell of each annular evaporation zone.

6. A crystallizer for oxalic acid crystals as claimed in claim 1, characterized in that: A baffle is installed in the annular evaporation zone. The baffle is connected to the crystallizer shell and the liquid containment device. An oxalic acid inlet is set on one side of the baffle, and a crystallization outlet is set on the other side of the baffle.

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