Device for judging scab degree of aluminum oxide fine liquid plate heat exchanger

Abstract

The utility model provides a device for judging the scab degree of an aluminum oxide fine liquid plate heat exchanger. The device comprises a plate heat exchanger, a fine liquid pipeline system, a circulating water pipeline system and a DCS (Distributed Control System) production control system, the circulating water pipeline system flows through the plate heat exchanger to cool the fine liquid pipeline system flowing through the plate heat exchanger; the DCS production control system dynamically opens and closes a regulating valve in the circulating water pipeline system by collecting information of temperature detection instruments in the semen pipeline system and the circulating water pipeline system. According to the utility model, the temperature difference calculation module value of the semen and the circulating cooling water and the opening value of the regulating valve can be detected online in real time; and logic judgment is carried out on the condition and a set value of a DCS production control system, and when all conditions are true, an alarm indication of scabbing cleaning is given.

Description

Technical Field

[0001] This utility model relates to a device and method for judging the degree of scaling in an alumina liquid plate heat exchanger, belonging to the field of intelligent control technology. Background Technology

[0002] In alumina production, the liquid cooling process involves exchanging the liquid produced by the leaf filter with heat through a plate heat exchanger. The cooled liquid is then mixed with aluminum hydroxide seeds (crystals) and sent to a seed separation tank for seed decomposition. The temperature control of the first tank in the seed separation tank has a significant impact on the decomposition rate and aluminum hydroxide particle size distribution. Since the temperature control and adjustment of the first tank is achieved through plate cooling, the ability to reasonably control the temperature of the first tank is a decisive factor in evaluating the heat exchange efficiency of the plate heat exchanger. During the heat exchange process, the supersaturated sodium aluminate solution (liquid) continuously decomposes, releasing aluminum hydroxide and small amounts of other impurities. This causes scale formation in the plate heat exchanger after a period of operation, affecting both heat exchange efficiency and limiting the flow capacity of the hot phase liquid (liquid). Therefore, plate heat exchangers need to be cleaned in a timely manner. Typical examples include the alumina decomposition tank scale cleaning device and method disclosed in Chinese Utility Model Patent CN201811200496.1; and the alumina decomposition tank scale cleaning device disclosed in Chinese Utility Model Patent CN201821671671.0. Otherwise, the plate heat exchanger will deteriorate, making it difficult to control the temperature of the first tank of the seed separation as required, resulting in passive production of the seed separation system and having a significant impact on the output and quality of the entire alumina system.

[0003] However, the inventors of this utility model patent have discovered the following problems in the prior art: the cleaning of scale on the plate-type heat exchanger is all done by manual judgment based on experience or by cleaning at fixed time intervals. Due to differences in individual experience and the limitations of mechanized work cycles, it may lead to untimely cleaning affecting production control or excessive cleaning causing waste of alkali and energy consumption. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a device and method for judging the degree of scaling in an alumina semen plate heat exchanger. It can detect the temperature difference calculation module value of semen and circulating cooling water and the opening value of the regulating valve in real time online; and make logical judgments with the set values ​​of the DCS production control system. When all conditions are true, it will issue an alarm indication for scaling cleaning.

[0005] This utility model is achieved through the following technical solution.

[0006] The present invention provides a device for judging the degree of scaling in an alumina semen plate heat exchanger, comprising a plate heat exchanger, a semen pipeline system, a circulating water pipeline system, and a DCS production control system; the circulating water pipeline system cools the semen pipeline system flowing through the plate heat exchanger; the DCS production control system dynamically opens and closes the regulating valves in the circulating water pipeline system by collecting temperature detection instrument information in the semen pipeline system and the circulating water pipeline system; the semen pipeline system and the circulating water pipeline system flow into and out of the plate heat exchanger from opposite directions.

[0007] The semen conduit system includes a semen tube and a semen inlet pipe temperature detection instrument “T1”; the semen inlet pipe temperature detection instrument “T1” is installed in the semen tube before it enters the plate heat exchanger.

[0008] The semen conduit system also includes a semen outlet pipe temperature detection instrument "T2"; the semen outlet pipe temperature detection instrument "T2" is installed in the semen pipe after the plate heat exchanger.

[0009] The circulating water pipeline system includes circulating water pipes, a circulating cooling water inlet pipe temperature measuring instrument "T3", and a circulating cooling water outlet pipe temperature measuring instrument "T4". The circulating cooling water inlet pipe temperature measuring instrument "T3" is installed in the circulating water pipe before entering the plate heat exchanger; the circulating cooling water outlet pipe temperature measuring instrument "T4" is installed in the circulating water pipe after exiting the plate heat exchanger.

[0010] The circulating water pipeline system also includes a regulating valve; the regulating valve is installed in the circulating water pipe after the plate heat exchanger, and is located before the temperature detection instrument "T4" of the circulating cooling water outlet pipe.

[0011] The DCS production control system includes a DCS control loop; the regulating valve is electrically connected to the "T2" temperature detection instrument for the semen outlet pipeline through the DCS control loop.

[0012] The beneficial effects of this invention are as follows: it can detect the temperature difference calculation module value of semen and circulating cooling water and the opening value of the regulating valve in real time; and make logical judgments with the set values ​​of the DCS production control system. When all conditions are true, it will issue an alarm indication for scaling cleaning; it can detect the scaling degree of plate heat exchangers in real time, avoid the consequences of untimely heat exchanger cleaning affecting production and avoid the waste of raw materials and energy caused by excessive cleaning. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the logic judgment process for cleaning scabs;

[0014] Figure 2 This is a schematic diagram of the temperature calculation process;

[0015] Figure 3 This is a schematic diagram of the existing production process;

[0016] In the diagram: 1-Plate heat exchanger, 2-Semen pipeline system, 21-Semen tube, 22-Semen inlet pipeline temperature measuring instrument "T1", 23-Semen outlet pipeline temperature measuring instrument "T2", 3-Circulating water pipeline system, 31-Circulating water pipe, 32-Circulating cooling water inlet pipeline temperature measuring instrument "T3", 33-Circulating cooling water outlet pipeline temperature measuring instrument "T4", 34-Regulating valve, 4-DCS production control system, 41-DCS control loop. Detailed Implementation

[0017] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0018] The first embodiment of this utility model relates to a device for judging the degree of scaling in an alumina liquid plate heat exchanger, such as... Figures 1-3 As shown, the system includes a plate heat exchanger 1, a semen pipeline system 2, a circulating water pipeline system 3, and a DCS production control system 4. The circulating water pipeline system 3 cools the semen pipeline system 2, which flows through the plate heat exchanger 1. The DCS production control system 4 dynamically controls the opening and closing of the regulating valve 34 in the circulating water pipeline system 3 by collecting temperature information from the temperature sensors in the semen pipeline system 2 and the circulating water pipeline system 3. The semen pipeline system 2 and the circulating water pipeline system 3 both flow through the plate heat exchanger 1. The plate heat exchanger 1 can control and regulate the temperature of the seed separation tank, and the temperature control of the seed separation tank has a significant impact on the seed decomposition rate and the particle size index of aluminum hydroxide. The semen pipeline system 2 and the circulating water pipeline system 3 flow into and out of the plate heat exchanger 1 from opposite directions. The high-temperature semen and the low-temperature circulating cooling water flow into the plate heat exchanger 1 from opposite directions for heat exchange, and the low-temperature circulating cooling water can remove the heat of the high-temperature semen to the maximum extent.

[0019] The second embodiment of this utility model is largely the same as the first embodiment, except that the semen conduit system 2 includes a semen tube 21 and a semen inlet pipe temperature detection instrument "T1" 22; the semen inlet pipe temperature detection instrument "T1" 22 is installed in the semen tube 21 before entering the plate heat exchanger 1. The semen tube 21 is used to transport semen; the semen inlet pipe temperature detection instrument "T1" is used to detect the temperature of the semen before it flows into the plate heat exchanger 1.

[0020] Furthermore, the semen conduit system 2 also includes a semen outlet pipe temperature detection instrument "T2" 23; the semen outlet pipe temperature detection instrument "T2" 23 is installed in the semen pipe 21 after exiting the plate heat exchanger 1. The semen outlet pipe temperature detection instrument "T2" 23 is used to detect the temperature of the semen flowing out of the plate heat exchanger 1.

[0021] Furthermore, the circulating water piping system 3 includes a circulating water pipe 31, a circulating cooling water inlet pipe temperature measuring instrument "T3" 32, and a circulating cooling water outlet pipe temperature measuring instrument "T4" 33. The circulating cooling water inlet pipe temperature measuring instrument "T3" 32 is installed in the circulating water pipe 31 before entering the plate heat exchanger 1; the circulating cooling water outlet pipe temperature measuring instrument "T4" 33 is installed in the circulating water pipe 31 after exiting the plate heat exchanger 1. The circulating water pipe 31 is used to transport cooling circulating water; the circulating cooling water inlet pipe temperature measuring instrument "T3" 32 is used to detect the temperature of the circulating cooling water before entering the plate heat exchanger 1; the circulating cooling water outlet pipe temperature measuring instrument "T4" 33 is used to detect the temperature of the circulating cooling water flowing out of the plate heat exchanger 1.

[0022] Furthermore, the circulating water piping system 3 also includes a regulating valve 34; the regulating valve 34 is installed in the circulating water pipe 31 after the plate heat exchanger 1, and is located before the circulating cooling water outlet pipe temperature detection instrument "T4" 33. The opening value of the regulating valve 34 can determine the flow rate of the circulating cooling water in the circulating water pipe 31, thereby affecting the heat exchange between the liquid and the circulating cooling water in the plate heat exchanger 1.

[0023] Furthermore, the DCS production control system 4 includes a DCS control loop; the regulating valve 34 is electrically connected to the semen outlet pipe temperature detection instrument "T2" 23 via the DCS control loop. The DCS control loop can acquire the electrical signal of the opening value of the regulating valve 34.

[0024] Based on the above, a typical working process of this utility model is as follows:

[0025] like Figure 1-3As shown, during operation, the regulating valve 34 has an initial opening value. Semen normally flows from the semen pipe 21 into the plate heat exchanger 1 and then out of the plate heat exchanger 1; circulating cooling water normally flows from the circulating water pipe 31 into the plate heat exchanger 1 and then out of the plate heat exchanger 1; then the DCS production control system 4 obtains values ​​from the semen inlet pipe temperature detection instrument "T1" 22 and the semen outlet pipe temperature detection instrument "T2" 23, forming ΔT1′; the DCS production control system 4 obtains values ​​from the circulating cooling water inlet pipe temperature detection instrument "T3" 32 and the circulating cooling water outlet pipe temperature detection instrument "T4" 33, forming ΔT2′; during production... At any given time, the DCS production control system 4 can acquire the values ​​obtained by the liquid inlet pipe temperature detection instrument "T1" 22 and the semen outlet pipe temperature detection instrument "T2" 23 to form ΔT1; acquire the values ​​obtained by the circulating cooling water inlet pipe temperature detection instrument "T3" 32 and the circulating cooling water outlet pipe temperature detection instrument "T4" 33 to form ΔT2; and acquire the opening value of the regulating valve 34; then perform logical judgment on the calculation module value (ΔT1 / ΔT1′), the calculation module value (ΔT2 / ΔT2′), and the real-time opening value of the regulating valve 34 with the set value of the DCS production control system. When all conditions are true, an alarm indication for scaling cleaning is issued.

Claims

1. A device for judging the degree of scaling in an alumina liquid plate heat exchanger, characterized in that: It includes a plate heat exchanger (1), a semen pipeline system (2), a circulating water pipeline system (3), and a DCS production control system (4); the circulating water pipeline system (3) flows through the plate heat exchanger (1) to cool down the semen pipeline system (2) flowing through the plate heat exchanger (1); the DCS production control system (4) dynamically controls the opening and closing of the regulating valve (34) in the circulating water pipeline system (3) by collecting temperature detection instrument information in the semen pipeline system (2) and the circulating water pipeline system (3); the semen pipeline system (2) and the circulating water pipeline system (3) flow into and out of the plate heat exchanger (1) from opposite directions.

2. The device for judging the degree of scaling in an alumina liquid plate heat exchanger as described in claim 1, characterized in that: The semen conduit system (2) includes a semen tube (21) and a semen inlet pipe temperature detection instrument "T1" (22); the semen inlet pipe temperature detection instrument "T1" (22) is installed in the semen tube (21) before entering the plate heat exchanger (1).

3. The device for judging the degree of scaling in an alumina liquid plate heat exchanger as described in claim 2, characterized in that: The semen conduit system (2) also includes a semen outlet pipe temperature detection instrument "T2" (23); the semen outlet pipe temperature detection instrument "T2" (23) is installed in the semen pipe (21) after the plate heat exchanger (1).

4. The device for judging the degree of scaling in an alumina liquid plate heat exchanger as described in claim 1, characterized in that: The circulating water pipeline system (3) includes a circulating water pipe (31), a circulating cooling water inlet pipe temperature detection instrument "T3" (32), and a circulating cooling water outlet pipe temperature detection instrument "T4" (33); the circulating cooling water inlet pipe temperature detection instrument "T3" (32) is installed in the circulating water pipe (31) before entering the plate heat exchanger (1); the circulating cooling water outlet pipe temperature detection instrument "T4" (33) is installed in the circulating water pipe (31) after exiting the plate heat exchanger (1).

5. The device for judging the degree of scaling in an alumina liquid plate heat exchanger as described in claim 4, characterized in that: The circulating water pipeline system (3) also includes a regulating valve (34); the regulating valve (34) is installed in the circulating water pipe (31) after the plate heat exchanger (1) and is located before the circulating cooling water outlet pipe temperature detection instrument "T4" (33).

6. The device for judging the degree of scaling in an alumina liquid plate heat exchanger as described in claim 1, characterized in that: The DCS production control system (4) includes a DCS control loop; the regulating valve (34) is electrically connected to the semen outlet pipe temperature detection instrument "T2" (23) through the DCS control loop.

Images