Anion detection device
The anion detection device efficiently separates and measures anions in the water-steam cycle by preheating and removing interfering substances, addressing the inefficiencies and high costs of conventional methods.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI HEAVY IND LTD
- Filing Date
- 2022-05-31
- Publication Date
- 2026-05-29
Smart Images
Figure 0007867379000001 
Figure 0007867379000002 
Figure 0007867379000003
Abstract
Description
Technical Field
[0001] The present disclosure relates to an anion detection device.
Background Art
[0002] In the water-steam cycle of a power plant, in order to prevent damage to system equipment and piping due to corrosion, strict management is carried out to prevent the mixing of components that cause corrosion, such as chloride ions and sulfate ions. However, due to factors such as seawater leakage caused by damage to the cooling pipes of the condenser or malfunction of the makeup water production device, the above-mentioned impurity components may混入 into the water-steam cycle. When impurities are混入, in order to minimize the pollution range and corrosion effect caused by the impurities as much as possible, it is necessary to promptly implement measures such as discharging the impurities outside the system by system water blowdown, adding chemicals to prevent pH decrease, plugging the leaking pipes, and stopping the plant operation. For this purpose, it is important to promptly detect the mixing of impurities, and the measurement of acid conductivity is carried out in many plants for the monitoring of impurities in the water-steam cycle.
[0003] Acid conductivity is a method of measuring the electrical conductivity after removing cation components by passing the sample water collected from the water-steam cycle through a cation exchange resin first. In the water-steam cycle, water treatment agents such as ammonia are added for corrosion inhibition. When a small amount of impurities is混入, the concentration of the water treatment agent is much larger than the impurity concentration. Therefore, the change in electrical conductivity due to the mixing of impurities is very small compared to the electrical conductivity due to the water treatment agent, and it is impossible to confirm the mixing of impurities by simply measuring the electrical conductivity. Therefore, by removing the water treatment agent (such as ammonia) with a cation exchange resin, eliminating the increase in electrical conductivity due to the water treatment agent, and exchanging the counter ions of the cations with H+ to increase the electrical conductivity per impurity concentration, highly sensitive detection of impurity mixing by electrical conductivity is enabled.
[0004] A specific example of this type of detection method / apparatus is the one described in Patent Document 1 below. Patent Document 1 below discloses a degassed acid conductivity meter as a method for measuring acid conductivity by removing carbon dioxide from feedwater and steam. This method measures acid conductivity without the influence of dissolved gases by performing degassing pretreatment of the sample before measuring acid conductivity. In this method, the target sample is heated to remove carbon dioxide through degassing, resulting in a system that can measure acid conductivity without the influence of carbon dioxide. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Patent No. 6108021 [Overview of the project] [Problems that the invention aims to solve]
[0006] In recent years, there has been a strong demand to increase the ammonia concentration injected into the feedwater to enhance corrosion resistance. However, in conventional systems, ammonia is initially removed with resin, so when the ammonia concentration in the feedwater increases, the breakthrough time of the resin shortens, leading to an increased frequency of resin replacement. This could result in higher operating costs for the equipment.
[0007] This disclosure was made to solve the above-mentioned problems and aims to provide an anion detection device that can efficiently and inexpensively detect anions. [Means for solving the problem]
[0008] To solve the above problems, the anion detection apparatus according to the present disclosure includes a supply pipe through which sample water containing multiple types of ions flows, a preheater provided on the supply pipe for preheating the sample water, a heating tank that further heats the preheated sample water to separate the multiple types of ions into steam containing substances derived from the ions to be separated and drain water, a discharge pipe for taking the drain water from the heating tank, an ion exchange unit provided on the discharge pipe and having an ion exchange resin for removing the ions to be separated that remain in the drain water, and the ion exchange unit on the discharge pipe The heating tank comprises a tank body, a supply unit provided at the top of the tank body for supplying the preheated sample water, a packing material disposed inside the tank body, a storage unit provided below the tank body for storing the preheated sample water, a heating unit provided in the storage unit for heating the sample water to generate steam, and a discharge unit for discharging the steam to the outside of the tank body, and the preheater preheats the sample water until the sample water is in a liquid phase state and the vapor pressure of the sample water is equal to atmospheric pressure. [Effects of the Invention]
[0009] According to this disclosure, it is possible to provide an anion detection device that can efficiently and inexpensively detect anions. [Brief explanation of the drawing]
[0010] [Figure 1] This is a schematic diagram showing the configuration of an anion detection device according to an embodiment of the present disclosure. [Figure 2] This is a cross-sectional view showing the configuration of a heating tank according to an embodiment of the present disclosure. [Figure 3] This is a cross-sectional view showing a first modified example of a heating tank according to the present disclosure. [Figure 4] This is a cross-sectional view showing a second modified example of the heating tank according to the present disclosure. [Figure 5] This is an enlarged cross-sectional view of a key part showing a third modified example of the heating tank according to the present disclosure. [Modes for carrying out the invention]
[0011] Hereinafter, an anion detection device 1 according to an embodiment of this disclosure will be described with reference to Figures 1 and 2. This anion detection device 1 is a device for detecting and measuring the concentration of anions contained in feedwater, condensate, drum water, and steam of a steam turbine plant. A steam turbine plant is equipped with a condenser to return high-temperature steam to a liquid phase state. The condenser is a heat exchanger that uses seawater or the like as a cooling medium to exchange heat between the seawater and the steam. Here, if the refrigerant piping in the condenser is damaged, the refrigerant such as seawater may leak into the feedwater, potentially damaging the piping and various devices.
[0012] Therefore, the anion detection device 1 is used to detect anions containing corrosion-causing components such as chloride ions (Cl-) as the anions to be detected. On the other hand, chemical solutions such as ammonia and hydrazine are injected into the water supply to prevent corrosion of the pipes. The anion detection device 1 detects and measures the concentration of anions such as chloride ions without being affected by these chemical solutions.
[0013] As shown in Figure 1, the anion detection device 1 comprises a supply pipe 10, a preheater 11, a heating tank 12, a discharge pipe 13, an ion exchange unit 14, a concentration detection unit 15, a first heat exchanger 16a, a second heat exchanger 16b, a first flow meter 17a, a second flow meter 17b, a steam discharge pipe 18, and a pump 19.
[0014] The supply pipe 10 is a piping through which feedwater, condensate, drum water, and sample water taken from the steam of the steam turbine plant flow. The supply pipe 10 extends from the inlet, which is the upstream end, to the heating tank 12. On the supply pipe 10, in order from upstream to downstream, are the first flow meter 17a, the first heat exchanger 16a, the second heat exchanger 16b, and the preheater 11.
[0015] The first flow meter 17a measures the flow rate of the sample water flowing through the supply pipe 10 and transmits it externally as a numerical value. As will be described in more detail later, heat exchange takes place between the steam and drain water supplied from the heating tank 12 and the sample water in the first heat exchanger 16a and the second heat exchanger 16b. As a result, the sample water is heated to a high temperature. The preheater 11 further heats the sample water with a heat transfer medium supplied from the outside. More specifically, the preheater 11 heats the sample water until its vapor pressure becomes equal to atmospheric pressure while maintaining a liquid phase state. In other words, the sample water that has passed through the preheater 11 is boiling due to sensible heat. In the following explanation, the sample water in this state may be simply referred to as "preheated sample water".
[0016] Next, the configuration of the heating tank 12 will be described with reference to Figure 2. The heating tank 12 includes a tank body 21, a supply unit 22, a packing material 23, a storage unit 24, a heating unit 25, and a discharge unit 26.
[0017] The tank body 21 is cylindrical in shape, extending vertically. The term "cylindrical" here includes cylindrical, rectangular, and polygonal cross-sectional shapes. A supply unit 22, connected to the aforementioned supply pipe 10, is provided at the top of the tank body 21. Preheated sample water flows into the tank body 21 through this supply unit 22.
[0018] A packing material 23 is placed inside the tank body 21. The packing material 23 is provided to promote the mixing of fluids inside the tank body 21 and to increase the contact area. Specific examples of the packing material 23 include shapes such as Raschig rings and Berl saddles.
[0019] Below the trough body 21, a storage part 24 is provided. The storage part 24 is a container for storing the sample water that has flowed downward in the trough body 21 through the supply part 22. Inside the storage part 24, a heating part 25 is provided. The heating part 25 heats the preheated sample water, that is, gives latent heat to generate steam. Specifically, as an example of the heating part 25, an electric heater capable of adjusting the heating temperature is preferably used. In addition, a ceramic heater or the like can also be used as the heating part 25. Also, the sample water that has overflowed from the storage part 24 is discharged to the outside through a pipe (not shown).
[0020] A discharge pipe 13 is connected to the storage part 24. The discharge pipe 13 extends from this storage part 24 to the concentration detection part 15. On the discharge pipe 13, a pump 19, a first heat exchanger 16a, a second flow meter 17b, an ion exchange part 14, and a concentration detection part 15 are arranged in this order. The sample water in the liquid phase state stored in the storage part 24 is sent to the first heat exchanger 16a by being pumped by the pump 19. In the first heat exchanger 16a, the sample water flowing through the supply pipe 10 and the high-temperature sample water pumped from the storage part 24 exchange heat. As a result, the sample water flowing through the supply pipe 10 is heated, and the sample water flowing through the discharge pipe 13 is cooled.
[0021] The second flow meter 17b measures the flow rate of the sample water flowing through the discharge pipe 13 and transmits it as a numerical value to the outside. The ion exchange part 14 removes, by means of an ion exchange resin, the cations including ammonia ions derived from the above-mentioned chemical solution among the ions contained in the sample water flowing through the discharge pipe 13 from the sample water. That is, the sample water passing through the ion exchange part 14 is in a state where only non-volatile anions (for example, chloride ions), which are one of the detection targets, are substantially contained. This concentration detection part 15 detects and measures the concentration of non-volatile anions containing chloride ions and transmits it as a numerical value to the outside. Specifically, the concentration detection part 15 is an electric conductivity meter. Since the electric conductivity changes based on the concentration of anions in the sample water, the concentration detection part 15 can finally obtain the concentration of anions by measuring the electric conductivity.
[0022] A discharge section 26 is provided at the top of the tank body 21. Steam generated by heating in the heating section 25 is discharged from the discharge section 26 located at the top of the tank body 21. As shown in Figure 1, a steam discharge pipe 18 extends between the discharge section 26 and the second heat exchanger 16b. The steam discharged from the discharge section 26 flows into the second heat exchanger 16b through the steam discharge pipe 18. Heat exchange takes place inside the second heat exchanger 16b between this steam and the sample water flowing through the supply pipe 10. As a result, the sample water is heated, and the steam is discharged to the outside in a liquid phase state or a gas-liquid mixed phase state.
[0023] (Effects and Benefits) Next, the operation of the anion detection device 1 will be explained. In order to operate the anion detection device 1, the sample water is first circulated through the supply pipe 10. At this time, it is assumed that the sample water contains chloride ions, which are the target of detection, as well as ammonia ions derived from the chemical solution and carbonate ions derived from carbon dioxide in the atmosphere. As the sample water flows through the supply pipe 10, it passes through the first heat exchanger 16a, the second heat exchanger 16b, and the preheater 11, and as described above, the whole or most of it remains in a liquid phase state while its vapor pressure becomes equal to atmospheric pressure.
[0024] The preheated sample water flows into the heating tank 12 via the supply unit 22. Within the tank body 21 of the heating tank 12, the sample water flows through the gaps between the packing materials 23 to the lower storage unit 24. The sample water that reaches the storage unit 24 is heated (gave latent heat) by the heating unit 25 and turns into steam. At this time, the steam contains little to no ammonia and carbon dioxide.
[0025] This steam flows upward through the tank body 21. Along the way, it comes into contact with the liquid-phase sample water flowing in from above. At this time, based on the double boundary film theory, ammonia ions and carbonate ions contained in the liquid-phase sample water move into the steam. In other words, as the liquid-phase sample water flows downward, it comes into contact with the steam from opposing directions for a longer period of time, so the concentration of ammonia ions and carbonate ions in the sample water decreases as it flows downward. This cycle is repeated until a steady state is reached. In the steady state, the liquid-phase sample water (drain water) stored in the storage section 24 contains only trace amounts of ammonia ions.
[0026] This drain water passes through the discharge pipe 13 to the first heat exchanger 16a and the second flow meter 17b, and then flows into the ion exchange section 14. In this ion exchange section 14, ammonia ions contained in the drain water are removed by the action of ion exchange resin. In other words, the drain water that has passed through the ion exchange section 14 contains only non-volatile anions, including chloride ions, which are the target of detection. Subsequently, the concentration of non-volatile anions in this drain water is detected and measured by an electrical conductivity meter, which serves as the concentration detection unit 15.
[0027] On the other hand, the steam that comes into contact with the preheated sample water midway through its upward flow within the tank body 21 contains ammonia and carbon dioxide. This steam is sent to the second heat exchanger 16b through the steam discharge pipe 18, and then discharged to the outside in a liquid phase or a gas-liquid mixed phase state.
[0028] As explained above, with the above configuration, after preheating by the preheater 11, the entire or most of the sample water remains in a liquid phase state, and its vapor pressure becomes equal to atmospheric pressure. Subsequently, the sample water that moves downward through the gaps in the packing material 23 into the tank body 21 comes into contact with the heating unit 25 in the storage unit 24 and becomes steam, i.e., in a gaseous state. At this time, the concentrations of ammonia and carbon dioxide contained in this steam become lower than the concentrations of ammonia and carbon dioxide contained in the liquid-phase sample water (drain water) stored in the storage unit 24. As this steam moves upward into the tank body 21, it comes into contact with new sample water flowing in from above. At this time, based on the concentration difference of ammonia and carbon dioxide between the two, ammonia and carbon dioxide move from the liquid-phase sample water to the gaseous (steam) sample water. In other words, the concentrations of ammonia and carbon dioxide contained in the liquid-phase sample water decrease as it moves downward. In particular, as described above, since the sample water and steam come into contact from opposing directions, a large concentration difference of ammonia and carbon dioxide between the sample water and steam can be maintained in the vertical direction within the tank body 21. This makes it possible to promote ion movement based on the double boundary membrane theory.
[0029] This continuous cycle maintains low concentrations of ammonia and carbon dioxide in the drain water stored in the storage unit 24. Subsequently, the ion exchange unit 14 removes the ammonia to be separated from the drain water. Then, the concentration detection unit 15 detects the concentration of the non-volatile anions to be detected (for example, chloride ions). In this way, it is possible to accurately measure only the concentration of the non-volatile anions to be detected after removing the ammonia and carbon dioxide to be separated in advance. As a result, for example, when operating a steam turbine plant, it is possible to immediately and accurately detect whether or not foreign substances such as seawater are mixed into the feedwater. Therefore, it becomes possible to operate the steam turbine plant more stably and smoothly.
[0030] In particular, the concentration of ammonia ions in the drain water flowing into the ion exchange unit 14 is already low due to the treatment by the heating tank 12. This reduces the load on the ion exchange resin in the ion exchange unit 14. Consequently, the time until the ion exchange resin breaks through can be extended, allowing for stable processing over a longer period. As a result, the operating costs of the device can be significantly reduced.
[0031] Furthermore, with the above configuration, since the heating unit 25 uses a heater (electric heater) whose heating temperature can be adjusted, it becomes possible to precisely control the amount of steam generated from the stored drain water. This makes it possible to keep the amount of steam generated at an appropriate level at all times. However, if excessive steam is generated, flooding may occur, causing the sample water to flow back, which could prevent normal measurement. However, by using the above configuration, flooding can be avoided.
[0032] Furthermore, with the above configuration, the sample water on the supply pipe 10 passes through the first heat exchanger 16a, allowing heat from the drain water to be transferred to the sample water. As a result, the sample water is heated prior to preheating by the preheater 11. Consequently, the output required of the preheater 11 is reduced. In other words, the performance requirements of the preheater 11 can be relaxed. This makes it possible to reduce the manufacturing and operating costs of the device.
[0033] Furthermore, with the above configuration, by passing through the second heat exchanger 16b in addition to the first heat exchanger 16a, it is possible to further raise the temperature of the sample water flowing through the supply pipe 10 prior to preheating by the preheater 11. As a result, the output required of the preheater 11 is further reduced, making it possible to further reduce the manufacturing and operating costs of the device.
[0034] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure.
[0035] For example, as shown in Figure 3 as a first modified example, a heater as an auxiliary heating unit 27 may be provided on the outer circumference of the tank body 21, covering the tank body 21. With this configuration, since the auxiliary heating unit 27 covers the periphery of the tank body 21, the temperature of the liquid-phase sample water moving downward inside the tank body 21 can be maintained at a high temperature, that is, immediately after preheating. This makes it possible to continuously maintain the movement of ammonia and carbon dioxide anions from the liquid-phase sample water to vapor, based on the concentration equilibrium described above.
[0036] Furthermore, as a second modification, as shown in Figure 4, a heater as an internal heating unit 28 may be provided inside the tank body 21, extending through the packing material 23. With this configuration, since the internal heating unit 28 is provided inside the tank body 21, the temperature of the liquid-phase sample water moving downward inside the tank body 21 can be maintained at an even more stable and higher level.
[0037] Furthermore, as a third modification, as shown in Figure 5, multiple baffles 29 may be provided below the supply unit 22 within the tank body 21 to disperse the flow direction of the sample water. With this configuration, the sample water can be distributed over a wider area within the tank body 21. Therefore, since more sample water can be processed in a shorter time, the device can be operated even more efficiently.
[0038] <Note> The anion detection device 1 described in each embodiment can be understood, for example, as follows.
[0039] (1) The anion detection device 1 according to the first embodiment includes a supply pipe 10 through which sample water containing multiple types of ions flows, a preheater 11 provided on the supply pipe 10 for preheating the sample water, a heating tank 12 that further heats the preheated sample water to separate it into steam containing substances derived from the ions to be separated from the multiple types of ions and drain water, a discharge pipe 13 for taking the drain water from the heating tank 12, an ion exchange unit 14 provided on the discharge pipe 13 and having an ion exchange resin for removing the ions to be separated that remain in the drain water, and provided on the downstream side of the ion exchange unit 14 on the discharge pipe 13 The heating tank 12 comprises a tank body 21, a supply unit 22 provided at the top of the tank body 21 for supplying the preheated sample water, a packing material 23 arranged inside the tank body 21, a storage unit 24 provided below the tank body 21 for storing the preheated sample water, a heating unit 25 provided in the storage unit 24 for heating the sample water to generate steam, and a discharge unit 26 for discharging the steam to the outside of the tank body 21. The preheater 11 preheats the sample water until the sample water is in a liquid phase state and the vapor pressure of the sample water is equal to atmospheric pressure.
[0040] According to the above configuration, after preheating by the preheater 11, the sample water maintains a liquid phase state while its vapor pressure becomes equal to atmospheric pressure. Subsequently, the sample water moves downward through the gaps in the packing material 23 within the tank body 21 and comes into contact with the heating unit 25 in the storage unit 24, becoming vapor, or a gaseous state. At this time, the concentration of anions contained in this vapor becomes lower than the concentration of anions contained in the liquid phase sample water (drain water) stored in the storage unit 24. As this vapor moves upward within the tank body 21, it comes into contact with new sample water flowing in from above. At this time, based on the difference in anion concentrations between the two, anions move from the liquid phase sample water to the gaseous (vapor) sample water. In other words, the concentration of anions contained in the liquid phase sample water decreases as it moves downward. This cycle occurs continuously, maintaining a low anion concentration in the drain water stored in the storage unit 24. Subsequently, the anions to be separated from the drain water are removed by the ion exchange unit 14. Next, the concentration detection unit 15 detects the concentration of the anion to be detected. In this way, it is possible to accurately measure only the concentration of the anion to be detected after removing the anions to be separated in advance.
[0041] (2) The anion detection device 1 according to the second embodiment is the anion detection device 1 of (1), further comprising an auxiliary heating unit 27 that surrounds the tank body 21.
[0042] With the above configuration, since the auxiliary heating unit 27 surrounds the tank body 21, the temperature of the liquid-phase sample water moving downward within the tank body 21 can be maintained at a high level. This makes it possible to continuously maintain the movement of anions from the liquid-phase sample water to vapor based on the concentration equilibrium described above.
[0043] (3) The anion detection device 1 according to the third embodiment is the anion detection device 1 according to (1) or (2), further comprising an internal heating unit 28 provided inside the tank body 21.
[0044] With the above configuration, since an internal heating unit 28 is provided inside the tank body 21, the temperature of the liquid-phase sample water moving downward inside the tank body 21 can be maintained at a more stable and higher level.
[0045] (4) The anion detection device 1 according to the fourth embodiment is the anion detection device 1 according to any one embodiment of (1) to (3), wherein the heating unit 25 is a heater capable of adjusting the temperature at which the sample water is heated.
[0046] With the above configuration, since the heating unit 25 uses a heater capable of adjusting the heating temperature, it becomes possible to precisely control the amount of steam generated from the stored drain water. This makes it possible to avoid flooding, which occurs when the steam flow rate exceeds the sample water flow rate.
[0047] (5) The anion detection device 1 according to the fifth embodiment is an anion detection device 1 according to any one embodiment of (1) to (4), further comprising a first heat exchanger 16a provided on the supply pipe 10 upstream of the preheater 11, which heats the sample water by exchanging heat between the sample water flowing through the supply pipe 10 and the drain water led from the discharge pipe 13.
[0048] With the above configuration, the heat from the drain water can be transferred to the sample water via the first heat exchanger 16a. As a result, the sample water is heated prior to preheating by the preheater 11. Consequently, the output required of the preheater 11 is reduced, making it possible to reduce the manufacturing and operating costs of the device.
[0049] (6) The anion detection device 1 according to the sixth embodiment is an anion detection device 1 according to any one embodiment of (1) to (5), further comprising a second heat exchanger 16b provided on the upstream side of the preheater 11 on the supply pipe 10, which heats the sample water by exchanging heat between the sample water flowing through the supply pipe 10 and the steam discharged from the discharge section 26.
[0050] With the above configuration, passing through the second heat exchanger 16b makes it possible to further raise the temperature of the sample water prior to preheating by the preheater 11. This further reduces the output required of the preheater 11, making it possible to further reduce the manufacturing and operating costs of the device. [Explanation of symbols]
[0051] 1…Anion detection device 10…Supply pipe 11… Preheater 12...Heating tank 13...Discharge pipe 14…Ion exchange section 15...Concentration detection unit 16a...First heat exchanger 16b…Second heat exchanger 17a...First flow meter 17b…Second flow meter 18... Steam exhaust pipe 19... Pump 21...tank body 22...Supply section 23...Filling 24... Storage section 25...Heating part 26…Discharge section 27…Auxiliary heating section 28...Internal heating section 29... Obstacle board
Claims
1. A supply pipe through which sample water containing multiple types of ions flows, A preheater is provided on the supply pipe for preheating the sample water, A heating tank further heats the preheated sample water to separate it into steam containing substances derived from the ions to be separated from the plurality of types of ions, and drain water. A discharge pipe for taking the drain water from the heating tank, An ion exchange unit provided on the aforementioned discharge pipe, having an ion exchange resin that removes the ions to be separated that remain in the drain water, A concentration detection unit is provided on the discharge pipe downstream of the ion exchange unit to detect the concentration of anions contained in the drain water, Equipped with, The aforementioned heating tank is The tank body and A supply unit is provided at the top of the tank body for supplying the preheated sample water, The filling material placed inside the tank body, A storage section is provided below the main body of the tank, where the preheated sample water is stored. A heating unit is provided in the storage unit, which heats the sample water to generate steam, A discharge section for discharging the steam to the outside of the tank body, It has, The preheater is an anion detection device that preheats the sample water until the sample water is in a liquid phase state and the vapor pressure of the sample water is equal to atmospheric pressure.
2. The anion detection device according to claim 1, further comprising an auxiliary heating section that surrounds the main body of the tank.
3. The anion detection device according to claim 1 or 2, further comprising an internal heating section provided inside the tank body.
4. The anion detection apparatus according to claim 1, wherein the heating unit is a heater capable of adjusting the temperature at which it heats the sample water.
5. The anion detection apparatus according to claim 1, further comprising a first heat exchanger provided upstream of the preheater on the supply pipe, which heats the sample water by exchanging heat between the sample water flowing through the supply pipe and the drain water introduced from the discharge pipe.
6. The anion detection apparatus according to claim 1, further comprising a second heat exchanger provided upstream of the preheater on the supply pipe, which heats the sample water by exchanging heat between the sample water flowing through the supply pipe and the steam discharged from the discharge section.