Automatic sugar adding device in caustic soda production

Abstract

The utility model relates to the technical field of caustic soda production, in particular to an automatic sugar adding device in caustic soda production, which comprises a preconcentrator, a first sugar liquid tank, a second sugar liquid tank and a sugar adding control unit, an inlet of the preconcentrator is fixedly communicated with a 48% alkali liquor pipeline, and a first sugar adding pipeline is fixedly communicated between a lower outlet of the first sugar liquid tank and an inlet of a first sugar adding pump. A second sugar adding pipeline is fixedly communicated between an outlet of the first sugar adding pump and the 48% alkali liquor pipeline, a first flow meter is fixedly arranged on the second sugar adding pipeline, and a second flow meter is fixedly arranged on the 48% alkali liquor pipeline between an inlet of the 48% alkali liquor pipeline and the second sugar adding pipeline; the sugar adding control unit transmits sugar adding flow data and 48% alkali liquor flow data to the PLC through the sensor, the PLC sends an instruction to the first sugar adding pump / the second sugar adding pump, the first sugar adding pump / the second sugar adding pump adjusts the sugar adding flow, and then automatic control over sugar adding in caustic soda production is achieved.

Description

Technical Field

[0001] This utility model relates to the field of caustic soda production technology and is an automatic sugar addition device in caustic soda production. Background Technology

[0002] Caustic soda has a wide range of applications, mainly in papermaking, printing and dyeing, oil refining, soap manufacturing, food processing, metallurgy, and many other fields. Its strong alkalinity makes it important in both industrial and daily life. The main production methods for caustic soda include the causticization method, the electrolysis method, and the ion exchange membrane method. The ion exchange membrane method is a relatively advanced method for producing caustic soda, combining the advantages of electrolysis and ion exchange technology to achieve high-purity, low-energy production. Refined brine is passed into an electrolytic cell equipped with an ion exchange membrane. During electrolysis, the ion exchange membrane allows sodium and hydroxide ions to pass through while blocking chloride and hydrogen ions, thus separating sodium hydroxide and chlorine gas. After electrolysis, a 32% sodium hydroxide dilute solution is obtained. This 32% alkali solution is then evaporated and concentrated to obtain a 48% liquid alkali. The 48% liquid alkali is then concentrated to 62% in a pre-concentrator. The 62% caustic soda solution is concentrated to 98.3% in the final concentrator, and then further concentrated to 98.5% in the flash tank. Finally, it is flaked / granulated and packaged to become the final solid caustic soda product.

[0003] Solid sodium hydroxide is white or nearly white, with a slight tint is permissible. With long-term operation of the production unit, the chlorate content in the caustic soda production system gradually increases. Chlorate corrosion of equipment leads to excessively high nickel content in the production system, causing the sodium hydroxide to turn black. In caustic soda product quality control, sugar is added to the alkali solution to control chlorate corrosion of nickel, thereby controlling the color of the caustic soda. The amount of sugar added affects the color; too little results in a greenish hue, while too much results in a blackish hue. To ensure caustic soda product quality, manual monitoring of the sugar addition amount is required hourly, along with adjusting the load. Real-time monitoring of product quality is not possible, and the workload for personnel is substantial.

[0004] Therefore, it is essential to research and invent an automatic sugar-adding device for caustic soda production. Summary of the Invention

[0005] This utility model provides an automatic sugar addition device for caustic soda production, which overcomes the shortcomings of the prior art and can effectively solve the problems of difficulty in controlling the amount of sugar added and high labor intensity in existing caustic soda production.

[0006] The technical solution of this utility model is achieved through the following measures: an automatic sugar addition device for caustic soda production, comprising a pre-concentrator, a first sugar solution tank, a first sugar addition pump, and a sugar addition control unit. The inlet of the pre-concentrator is fixedly connected to a 48% alkali solution pipeline. The lower outlet of the first sugar solution tank is fixedly connected to the inlet of the first sugar addition pump via a first sugar addition pipeline. The outlet of the first sugar addition pump is fixedly connected to the 48% alkali solution pipeline via a second sugar addition pipeline. A first flow meter is fixedly installed on the second sugar addition pipeline. A second flow meter is fixedly installed on the 48% alkali solution pipeline between the inlet of the 48% alkali solution pipeline and the second sugar addition pipeline. The sugar addition control unit includes a first flow meter, a second flow meter, a first sugar addition pump, and a PLC controller. The first flow meter, the second flow meter, and the first sugar addition pump are all connected to the PLC controller.

[0007] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution:

[0008] The above also includes a second sugar solution tank and a second sugar addition pump. A third sugar addition pipeline is fixedly connected between the lower outlet of the second sugar solution tank and the first sugar addition pipeline. A fourth sugar addition pipeline is fixedly connected between the third sugar addition pipeline and the inlet of the second sugar addition pump. A fifth sugar addition pipeline is fixedly connected between the outlet of the second sugar addition pump and the second sugar addition pipeline between the first sugar addition pump and the first flow meter.

[0009] The aforementioned sugar addition control unit also includes a second sugar addition pump, which is connected to the PLC controller via a sensor.

[0010] The first and second sugar-adding pumps mentioned above are variable frequency diaphragm pumps.

[0011] A flushing pipeline is fixedly connected to the second sugar addition pipeline between the fifth sugar addition pipeline and the first flow meter. A first preparation pipeline is fixedly connected to the top inlet of the first sugar solution tank and the flushing pipeline. A second preparation pipeline is fixedly connected to the top inlet of the second sugar solution tank and the flushing pipeline between the first preparation pipeline and the second sugar addition pipeline. A control valve is fixedly installed on the flushing pipeline between the second preparation pipeline and the second sugar addition pipeline.

[0012] On the second sugar addition pipeline between the first sugar addition pump and the first flow meter, a first pressure regulating valve and a first pressure gauge are fixedly installed in sequence according to the direction of medium flow. On the fifth sugar addition pipeline, a second pressure regulating valve and a second pressure gauge are fixedly installed in sequence according to the direction of medium flow.

[0013] The first and second sugar solution tanks are each equipped with a filter screen.

[0014] A first filter and a second filter are fixedly installed on the first sugar addition pipeline and the fourth sugar addition pipeline, respectively, between the third sugar addition pipeline and the first sugar addition pump.

[0015] The first sugar addition pipeline between the first filter and the first sugar addition pump, the second sugar addition pipeline between the first pressure regulating valve and the first pressure gauge, the fourth sugar addition pipeline between the second filter and the second sugar addition pump, and the fifth sugar addition pipeline between the second pressure regulating valve and the second pressure gauge are all equipped with detachable flexible connection pipelines.

[0016] The aforementioned control valve, first pressure regulating valve, first pressure gauge, second pressure regulating valve, and second pressure gauge are all connected to the PLC controller. An interlock is provided between the first pressure regulating valve and the first pressure gauge, an interlock is provided between the second pressure regulating valve and the second pressure gauge, and an interlock is provided between the second sugar adding pump and the first flow meter and the second flow meter.

[0017] This utility model has a reasonable and compact structure and is easy to use. It uses a sugar addition control unit to transmit sugar addition flow data and 48% alkali solution flow data to a PLC controller. The PLC controller sends instructions to the first sugar addition pump / second sugar addition pump, which adjusts the sugar addition flow rate, thereby realizing automatic control of sugar addition in caustic soda production. It has the characteristics of safety, labor saving, simplicity and high efficiency. Attached Figure Description

[0018] Appendix Figure 1 This is a schematic diagram of the process flow of this utility model.

[0019] Appendix Figure 1 The codes in the diagram are as follows: 1 for pre-concentrator, 2 for first sugar solution tank, 3 for first sugar addition pump, 4 for PLC controller, 5 for 48% alkali solution pipeline, 6 for first sugar addition pipeline, 7 for second sugar addition pipeline, 8 for first flow meter, 9 for second flow meter, 10 for second sugar solution tank, 11 for second sugar addition pump, 12 for third sugar addition pipeline, 13 for fourth sugar addition pipeline, 14 for fifth sugar addition pipeline, 15 for flushing pipeline, 16 for first preparation pipeline, 17 for second preparation pipeline, 18 for control valve, 19 for first pressure regulating valve, 20 for first pressure gauge, 21 for second pressure regulating valve, 22 for second pressure gauge, 23 for filter screen, 24 for first filter, and 25 for second filter. Detailed Implementation

[0020] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0021] Unless otherwise specified, all equipment and devices used in this invention are existing, publicly known, and commonly used equipment and devices in the field.

[0022] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0023] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0024] Example 1: As shown in the attached document Figure 1 As shown, the automatic sugar addition device in the caustic soda production includes a pre-concentrator 1, a first sugar solution tank 2, a first sugar addition pump 3, and a sugar addition control unit. The inlet of the pre-concentrator 1 is fixedly connected to a 48% alkali solution pipeline 5. The lower outlet of the first sugar solution tank 2 is fixedly connected to the inlet of the first sugar addition pump 3 via a first sugar addition pipeline 6. The outlet of the first sugar addition pump 3 is fixedly connected to the 48% alkali solution pipeline 5 via a second sugar addition pipeline 7. A first flow meter 8 is fixedly installed on the second sugar addition pipeline 7. A second flow meter 9 is fixedly installed on the 48% alkali solution pipeline 5 between the inlet of the 48% alkali solution pipeline 5 and the second sugar addition pipeline 7. The sugar addition control unit includes the first flow meter 8, the second flow meter 9, the first sugar addition pump 3, and a PLC controller 4.

[0025] In this invention, the first flow meter 8, the second flow meter 9, and the first sugar addition pump 3 are all connected to the PLC controller 4. The first flow meter 8 and the second flow meter 9 obtain sugar addition flow data and 48% alkali solution flow data respectively through monitoring. After the sugar addition flow data and 48% alkali solution flow data are transmitted to the PLC controller 4 by the corresponding flow sensors, the PLC controller 4 sends a command to the first sugar addition pump 3, which adjusts the sugar addition flow to realize automatic control of sugar addition in caustic soda production.

[0026] As needed, the first flow meter 8 is used to monitor the sugar addition flow rate and can be set with alert alarm values ​​(a high alarm value of 120 g / t and a low alarm value of 80 g / t, which can be modified according to the chlorate concentration in the 32% alkali solution); the second flow meter 9 is used to monitor the 48% alkali solution delivery flow rate. In actual production, during the adjustment of the caustic soda production load, the sugar addition flow rate is automatically adjusted by the first sugar addition pump 3.

[0027] After the sugar solution prepared in the first sugar solution tank 2 reaches the standard, it is transported to the 48% alkali solution pipeline 5 by the first sugar addition pump 3. After the sugar solution and 48% alkali solution are mixed, they are transported to the pre-concentrator 1, where the concentration of alkali solution is further increased.

[0028] The automatic sugar addition device in the above-mentioned caustic soda production process can be further optimized and / or improved according to actual needs:

[0029] Example 2: Its difference from Example 1 is as follows: (See attached) Figure 1As shown, it also includes a second sugar solution tank 10 and a second sugar addition pump 11. A third sugar addition pipeline 12 is fixedly connected between the lower outlet of the second sugar solution tank 10 and the first sugar addition pipeline 6. A fourth sugar addition pipeline 13 is fixedly connected between the third sugar addition pipeline 12 and the inlet of the second sugar addition pump 11. A fifth sugar addition pipeline 14 is fixedly connected between the outlet of the second sugar addition pump 11 and the second sugar addition pipeline 7 between the first sugar addition pump 3 and the first flow meter 8.

[0030] As needed, the second sugar solution tank 10 and the first sugar solution tank 2 serve as backups for each other. One sugar solution tank is used for sugar solution preparation, and the other sugar solution tank is used for storing qualified sugar solution. The second sugar addition pump 11 and the first sugar addition pump 3 serve as backups for each other. When one sugar addition pump fails and is under maintenance, the other sugar addition pump will work normally to ensure normal production.

[0031] Example 3: Its difference from Examples 1 to 2 is as follows: (See attached) Figure 1 As shown, the sugar addition control unit also includes a second sugar addition pump 11, which is connected to the PLC controller 4 via a sensor.

[0032] As needed, the PLC controller 4 sends instructions to the second sugar pump 11, which then adjusts the sugar flow rate.

[0033] Example 4: Its difference from Examples 1 to 3 is as follows: (See attached) Figure 1 As shown, the first sugar pump 3 and the second sugar pump 11 are diaphragm pumps with variable frequency control.

[0034] The flow rate of the sugar solution can be controlled by adjusting the output frequency of the diaphragm pump as needed.

[0035] Example 5: It differs from Examples 1 to 4 in that, as shown in the appendix... Figure 1 As shown, a flushing pipeline 15 is fixedly connected to the second sugar addition pipeline 7 between the fifth sugar addition pipeline 14 and the first flow meter 8. A first preparation pipeline 16 is fixedly connected between the top inlet of the first sugar solution tank 2 and the flushing pipeline 15. A second preparation pipeline 17 is fixedly connected between the top inlet of the second sugar solution tank 10 and the flushing pipeline 15 between the first preparation pipeline 16 and the second sugar addition pipeline 7. A control valve 18 is fixedly installed on the flushing pipeline 15 between the second preparation pipeline 17 and the second sugar addition pipeline 7.

[0036] As needed, the medium transported in the first preparation pipeline 16, the second preparation pipeline 17, and the flushing pipeline 15 can be secondary condensate.

[0037] In this invention, the alkali solution passing through the pre-concentrator 1 exchanges heat with molten salt in the final concentrator, increasing the alkali solution concentration from 62% to 98%. The secondary steam generated by the final concentrator heats the pre-concentrator 1, and the resulting condensate is the secondary condensate. The secondary condensate has a temperature of about 80°C and is used for sugar solution preparation and flushing the first flow meter 8 and the second sugar addition pipeline 7 when the caustic soda production system is shut down. This prevents the sugar solution adsorbed in the sugar addition pipeline from deteriorating, while also ensuring the accuracy of the first flow meter 8.

[0038] Example 6: Its difference from Examples 1 to 5 is as follows: (See attached) Figure 1 As shown, a first pressure regulating valve 19 and a first pressure gauge 20 are fixedly installed on the second sugar adding pipeline 7 between the first sugar adding pump 3 and the fifth sugar adding pipeline 14 in sequence according to the direction of medium flow. A second pressure regulating valve 21 and a second pressure gauge 22 are fixedly installed on the fifth sugar adding pipeline 14 in sequence according to the direction of medium flow.

[0039] Example 7: Its difference from Examples 1 to 6 is as follows: (See attached) Figure 1 As shown, filter screens 23 are fixedly installed inside the first sugar solution tank 2 and the second sugar solution tank 10 respectively.

[0040] Example 8: It differs from Examples 1 to 7 in that: as shown in the appendix Figure 1 As shown, a first filter 24 and a second filter 25 are fixedly installed on the first sugar addition line 6 between the third sugar addition line 12 and the first sugar addition pump 3, and on the fourth sugar addition line 13, respectively.

[0041] Example 9: It differs from Examples 1 to 8 in that: as shown in the appendix Figure 1 As shown, the first sugar addition line 6 between the first filter 24 and the first sugar addition pump 3, the second sugar addition line 7 between the first pressure regulating valve 19 and the first pressure gauge 20, the fourth sugar addition line 13 between the second filter 25 and the second sugar addition pump 11, and the fifth sugar addition line 14 between the second pressure regulating valve 21 and the second pressure gauge 22 are all equipped with detachable flexible connection lines.

[0042] As needed, the sugar addition pipelines before and after the first sugar addition pump 3 and the second sugar addition pump 11 are set as detachable flexible connection pipelines. If the first sugar addition pipeline 6, the second sugar addition pipeline 7, the third sugar addition pipeline 12, the fourth sugar addition pipeline 13, the first pressure regulating valve 19, the second pressure regulating valve 21, the first sugar addition pump 3, and the second sugar addition pump 11 become blocked, they can be quickly disassembled and cleaned.

[0043] Example 10: It differs from Examples 1 to 9 in that, as shown in the appendix... Figure 1As shown, control valve 18, first pressure regulating valve 19, first pressure gauge 20, second pressure regulating valve 21, and second pressure gauge 22 are all connected to PLC controller 4. An interlock is provided between the first pressure regulating valve 19 and the first pressure gauge 20, an interlock is provided between the second pressure regulating valve 21 and the second pressure gauge 22, and an interlock is provided between the second sugar pump 11 and the first flow meter 8 and the second flow meter 9.

[0044] As needed, the first pressure gauge 20 and the second pressure gauge 22 monitor and obtain the pressure data of the second sugar addition pipeline 7 and the fifth sugar addition pipeline 14, respectively. By setting the control range values ​​for the first pressure gauge 20 and the second pressure gauge 22, during normal production, the sensors transmit the pressure data to the PLC controller 4. The PLC controller 4 issues commands to the first pressure regulating valve 19 and the second pressure regulating valve 21, respectively. The first pressure regulating valve 19 and the second pressure regulating valve 21 adjust the valve opening to achieve automatic adjustment of the pressure data.

[0045] Depending on the needs, the pipelines and equipment of the automatic sugar addition device in the caustic soda production process can also be equipped with conventional valves, thermometers, and pressure gauges known and commonly used in the field. The PLC controller can be a Siemens S7-1500, which is equipped with a Yokogawa CS3000 DCS control system.

[0046] The above technical features constitute various embodiments of this utility model, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0047] The usage process of this utility model embodiment is described using the first sugar solution tank 2 and the first sugar addition pump 3 as an example. First, the sugar solution is prepared in the first sugar solution tank 2 to obtain a qualified sugar solution; then, the qualified sugar solution is transported to the 48% alkali solution pipeline 5 through the first sugar addition pump 3; finally, the sugar addition control unit automatically adjusts the amount of sugar added as needed.

Claims

1. An automatic sugar-adding device for caustic soda production, characterized in that... The system includes a pre-concentrator, a first sugar solution tank, a first sugar addition pump, and a sugar addition control unit. The inlet of the pre-concentrator is fixedly connected to a 48% alkali solution pipeline. The lower outlet of the first sugar solution tank is fixedly connected to the inlet of the first sugar addition pump via a first sugar addition pipeline. The outlet of the first sugar addition pump is fixedly connected to the 48% alkali solution pipeline via a second sugar addition pipeline. A first flow meter is fixedly installed on the second sugar addition pipeline. A second flow meter is fixedly installed on the 48% alkali solution pipeline between the inlet of the 48% alkali solution pipeline and the second sugar addition pipeline. The sugar addition control unit includes a first flow meter, a second flow meter, a first sugar addition pump, and a PLC controller. The first flow meter, the second flow meter, and the first sugar addition pump are all connected to the PLC controller.

2. The automatic sugar addition device for caustic soda production according to claim 1, characterized in that... It also includes a second sugar solution tank and a second sugar addition pump. A third sugar addition pipeline is fixedly connected between the lower outlet of the second sugar solution tank and the first sugar addition pipeline. A fourth sugar addition pipeline is fixedly connected between the third sugar addition pipeline and the inlet of the second sugar addition pump. A fifth sugar addition pipeline is fixedly connected between the outlet of the second sugar addition pump and the second sugar addition pipeline between the first sugar addition pump and the first flow meter.

3. The automatic sugar addition device for caustic soda production according to claim 2, characterized in that... The sugar addition control unit also includes a second sugar addition pump, which is connected to the PLC controller via a sensor.

4. The automatic sugar addition device for caustic soda production according to claim 2 or 3, characterized in that... The first and second sugar-adding pumps are variable frequency diaphragm pumps.

5. The automatic sugar addition device for caustic soda production according to claim 4, characterized in that... A flushing pipeline is fixedly connected to the second sugar addition pipeline between the fifth sugar addition pipeline and the first flow meter. A first preparation pipeline is fixedly connected to the top inlet of the first sugar solution tank and the flushing pipeline. A second preparation pipeline is fixedly connected to the top inlet of the second sugar solution tank and the flushing pipeline between the first preparation pipeline and the second sugar addition pipeline. A control valve is fixedly installed on the flushing pipeline between the second preparation pipeline and the second sugar addition pipeline.

6. The automatic sugar addition device for caustic soda production according to claim 2, 3, or 5, characterized in that... On the second sugar addition pipeline between the first sugar addition pump and the first flow meter, a first pressure regulating valve and a first pressure gauge are fixedly installed in sequence according to the direction of medium flow. On the fifth sugar addition pipeline, a second pressure regulating valve and a second pressure gauge are fixedly installed in sequence according to the direction of medium flow.

7. The automatic sugar addition device for caustic soda production according to claim 6, characterized in that... The first and second sugar solution tanks are each equipped with a fixed filter screen.

8. The automatic sugar addition device for caustic soda production according to claim 2, 3, 5, or 7, characterized in that... A first filter and a second filter are fixedly installed on the first sugar addition pipeline between the third sugar addition pipeline and the first sugar addition pump, and on the fourth sugar addition pipeline, respectively.

9. The automatic sugar addition device for caustic soda production according to claim 8, characterized in that... The first sugar addition pipeline between the first filter and the first sugar addition pump, the second sugar addition pipeline between the first pressure regulating valve and the first pressure gauge, the fourth sugar addition pipeline between the second filter and the second sugar addition pump, and the fifth sugar addition pipeline between the second pressure regulating valve and the second pressure gauge are all equipped with detachable flexible connection pipelines.

10. The automatic sugar addition device for caustic soda production according to claim 7 or 9, characterized in that... The control valve, the first pressure regulating valve, the first pressure gauge, the second pressure regulating valve, and the second pressure gauge are all connected to the PLC controller. An interlock is set between the first pressure regulating valve and the first pressure gauge, an interlock is set between the second pressure regulating valve and the second pressure gauge, and an interlock is set between the second sugar adding pump and the first flow meter and the second flow meter.

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