JP2015124959A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner capable of improving a bactericidal effect of drain water irrespective of water quality of the drain water.SOLUTION: An air conditioner which includes a drain pan 7 for receiving drain water 8 generating in a heat exchanger 6 includes: a silver ion generating unit 1 for eluting silver ions in the drain water 8; and a silver ion bactericidal effect facilitation unit 2 for facilitating the bactericidal effect of the drain water 8 by the silver ions. The silver ion bactericidal effect facilitation unit 2 elutes at least one kind of metal ions other than the silver ions in the drain water 8.

Description

  The present invention relates to an air conditioner that sterilizes microorganisms of drain water generated during cooling of indoor air with metal ions.

  In general, an air conditioner is known that includes a heat exchanger, a drain pan that receives drain water flowing down from the heat exchanger, and a drain pump that pumps up and drains the drain water accumulated in the drain pan. In this type of air conditioner, microorganisms propagate in the drain water stored in the drain pan, and semi-solid slime (hereinafter referred to as slime) may be generated. The slime may clog the drain pump or drain hose.

  In order to solve this problem, an antibacterial agent that suppresses generation of slime by elution of silver ions has been proposed (see, for example, Patent Documents 1 and 2).

JP 2006-52918 A JP 2012-7870 A

  However, since the quality of the drain water varies depending on the installation location, installation environment, installation status, etc., the amount of silver ions eluted from the antibacterial agent into the drain water varies greatly. Depending on the quality of the drain water, there is a problem that the amount of silver ions eluted from the antibacterial agent is small and the bactericidal effect is lowered.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an air conditioner that can improve the sterilizing effect of drain water regardless of the quality of the drain water.

  An air conditioner according to the present invention is an air conditioner including a drain pan that receives drain water generated by a heat exchanger, and a silver ion generator that elutes silver ions into the drain water, and at least other than silver ions A silver ion sterilization effect promoting part for eluting one type of metal ion into the drain water.

  According to the present invention, since the sterilization effect of drain water by silver ions is promoted by the silver ion sterilization effect promoting portion, the sterilization effect of drain water can be improved regardless of the water quality of the drain water.

It is sectional drawing which shows the whole structure of the air conditioner which concerns on Embodiment 1 of this invention. It is general | schematic sectional drawing which shows the structure of the drain pan 7 vicinity of the air conditioner which concerns on Embodiment 1 of this invention. It is a schematic top view which shows the structure which looked at the drain pan 7 of the air conditioner which concerns on Embodiment 1 of this invention from upper direction. In the air conditioner according to Embodiment 1 of the present invention, when a borosilicate glass antibacterial agent is used as the silver ion generation unit 1, the drain water 8 having an electric conductivity of 20 μS / cm is sterilized with silver ions. It is a graph which shows the relationship between the amount of silver ion elution, and the microorganism viability of drain water. In the air conditioner which concerns on Embodiment 1 of this invention, it is a graph which shows the relationship between the electrical conductivity of the drain water 8 at the time of using a borosilicate glass antibacterial agent as the silver ion generation part 1, and silver ion elution amount. . The relationship between the electrical conductivity of the drain water 8 in the air conditioner according to Embodiment 1 of the present invention and the survival rate after the microorganisms of the drain water 8 are allowed to stand for 8 hours in the presence of the silver ion generation unit 1. It is a graph to show. In the air conditioner according to Embodiment 1 of the present invention, copper ions are added to drain water 8 having an electric conductivity of 120 μS / cm, and 5 g / L of borosilicate glass antibacterial agent is added as silver ion generation unit 1 It is a graph which shows the relationship between a copper ion density | concentration and the survival rate of the microorganisms 8 hours after the drain water 8. FIG. In the air conditioner according to Embodiment 1 of the present invention, the copper surface area and drain required to elute 0.1 mg / L of copper ions in 24 hours with respect to drain water 8 having an electric conductivity of 120 μS / cm It is a graph which shows the relationship with the quantity of water 8. FIG. It is a graph which shows an example of the relationship between the water level of the drain water 8, and the quantity of the drain water 8 in the air conditioner which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the structure of the silver ion sterilization effect promotion part 2 in the air conditioner which concerns on Embodiment 1 of this invention. It is a graph which shows the relationship between the distance of the silver ion generation part 1 and the silver ion sterilization effect promotion part 2 in the air conditioner which concerns on Embodiment 1 of this invention, and a sterilization effect. It is a figure which shows another example of the positional relationship of the silver ion generation part 1 and the silver ion sterilization effect promotion part 2 in the air conditioner which concerns on Embodiment 1 of this invention. In the air conditioner which concerns on Embodiment 1 of this invention, it is a graph which shows the influence of the copper ion elution state with respect to the bactericidal effect of the silver ion eluted from the silver ion generation part 1. FIG. It is explanatory drawing which shows the example of operation | movement of the air conditioner which concerns on Embodiment 1 of this invention. In the air conditioner concerning Embodiment 1 of this invention, it is the graph which compared ratio of the bactericidal effect by the presence or absence of stirring implementation of the drain water. It is a figure which shows the experimental conditions 1 and 2 and the comparative conditions 1-4 in Example 1 of Embodiment 1 of this invention. It is a graph which shows the experimental result in Example 1 of Embodiment 1 of this invention. It is general | schematic sectional drawing which shows the structure of the drain pan 7 vicinity of the air conditioner which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows the example of operation | movement of the air conditioner which concerns on Embodiment 2 of this invention. It is general | schematic sectional drawing which shows the structure of the drain pan 7 vicinity of the air conditioner which concerns on Embodiment 3 of this invention. It is explanatory drawing which shows the example of operation | movement of the air conditioner which concerns on Embodiment 3 of this invention. It is a figure which shows typically the example of a structure of the electrode pairs 9 and 11 in the air conditioner which concerns on Embodiment 3 of this invention. It is general | schematic sectional drawing which shows the structure of the drain pan 7 vicinity of the air conditioner which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
An air conditioner according to Embodiment 1 of the present invention will be described. FIG. 1 is a cross-sectional view showing the overall configuration of the air conditioner according to the present embodiment. In the present embodiment, a ceiling cassette type four-way air conditioner (indoor unit) will be described as an example. In the following drawings including FIG. 1, the dimensional relationship and shape of each component may be different from the actual one. The positional relationship (for example, up-and-down relationship) between each structural member in a specification is a thing when installing an air conditioner in the state which can be used in principle.

  As shown in FIG. 1, the air conditioner according to the present embodiment includes a main body casing 21 that is open at the bottom, and a centrifugal electric blower 22 (indoor blower) provided at the center of the ceiling surface of the main body casing 21. ) And. The rotating shaft of the electric blower 22 extends in the vertical direction. Below the electric blower 22, an air suction port 27 through which room air flows into the electric blower 22 is formed. A suction grill 28 is attached to the air suction port 27.

  On the outer peripheral side (radially outer side) of the electric blower 22, a heat exchanger 6 (indoor heat exchanger) is provided so as to surround the electric blower 22. The heat exchanger 6 constitutes a refrigeration cycle apparatus together with a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and the like (not shown). During the cooling operation, the heat exchanger 6 functions as an evaporator. At this time, the indoor air that is blown by the electric blower 22 and passes through the heat exchanger 6 is cooled by the heat exchange with the refrigerant and becomes cold air. On the other hand, at the time of heating operation, the heat exchanger 6 functions as a condenser by switching the four-way valve. At this time, the indoor air that is blown by the electric blower 22 and passes through the heat exchanger 6 is heated by heat exchange with the refrigerant to become warm air.

  A drain pan 7 that receives drain water generated by the heat exchanger 6 is provided below the heat exchanger 6. The drain pan 7 is disposed at least on the lower projection surface (directly below) of the entire heat exchanger 6. Below the drain pan 7, a decorative panel 26 exposed on the ceiling surface of the room is provided. The decorative panel 26 has an opening serving as the air suction port 27 and a frame-shaped portion surrounding the periphery of the opening in a rectangular frame shape. Air outlets 29 are formed on each of the four sides of the frame-shaped portion. The conditioned air that has been cooled or heated after passing through the heat exchanger 6 passes through the air passage 24 in the main body casing 21 and is blown out from the air outlet 29 in four directions in the room. Each air outlet 29 is provided with a wind direction plate 29a for adjusting the wind direction of the conditioned air.

  FIG. 2 is a schematic cross-sectional view showing a configuration in the vicinity of the drain pan 7 of the air conditioner according to the present embodiment. FIG. 3 is a schematic plan view showing the configuration of the drain pan 7 as viewed from above. As shown in FIGS. 2 and 3, on the drain pan 7, a heat exchanger 6, a drain pump 4 that discharges the drain water 8 received by the drain pan 7, and a water level sensor 5 that detects the water level of the drain water 8, A drain pan sterilization mechanism 3 including a silver ion generation unit 1 and a silver ion sterilization effect promotion unit 2 is provided. The silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 are installed in a drain water flow path 15 (see FIG. 3) through which drain water 8 generated by the heat exchanger 6 is discharged by the drain pump 4. The lower end of the silver ion generating unit 1 is disposed, for example, above the water level (the height of the suction port 4a of the drain pump 4; the lower limit water level 17) when drainage is performed by the drain pump 4 during the cooling operation. ing. Moreover, the lower end of the silver ion generation part 1 is arrange | positioned below the upper limit water level 18 mentioned later or the lower limit than it. At least a part of the silver ion sterilization effect promoting portion 2 is disposed below the lower limit water level 17. The silver ion generation part 1 and the silver ion sterilization effect promotion part 2 are spaced apart so as not to contact each other. In this example, the silver ion generation part 1 is arrange | positioned at the drain water flow path 15 used as the inner peripheral side of the heat exchanger 6 by planar view, and the silver ion sterilization effect promotion part 2 is heat exchanger 6 by planar view. Is disposed in the drain water flow path 15 on the outer peripheral side.

  The silver ion generator 1 used in the present embodiment is one in which silver or silver ions are uniformly contained in a solid material. When the silver ion generator 1 touches the drain water 8 or dissolves in the drain water 8, silver or silver ions contained in the silver ion generator 1 are released into the drain water 8 as silver ions. Inorganic antibacterial agents that do not contain organic substances are commercially available products that are designed to dissolve gradually. In this embodiment, a borosilicate glass antibacterial agent for glass tablets is used as such an inorganic antibacterial agent. A glass tablet contains an inorganic antibacterial component such as silver ions in a glass network molecular structure. The glass tablet elutes silver ions when dissolved in water. Since the dissolution rate of the inorganic antibacterial agent is almost proportional to the silver ion elution rate, the silver ion elution rate can be adjusted by changing the specifications of the glass tablet. The inorganic antibacterial agent is not particularly limited to the borosilicate glass antibacterial agent, and for example, a phosphoric acid type, a silicic acid type, or a zeolite type can be used.

  FIG. 4 shows the air conditioner according to the present embodiment, when a borosilicate glass antibacterial agent is used as the silver ion generator 1 and the drain water 8 having an electric conductivity of 20 μS / cm is sterilized with silver ions. It is a graph which shows the relationship between the amount of elution of silver ion, and the microorganism viability of drain water 8. The horizontal axis of the graph represents the concentration of silver ions eluted from the silver ion generator 1 into the drain water 8 after 24 hours, that is, the silver ion elution amount (mg / L). The vertical axis of the graph represents the survival rate of microorganisms of drain water 8 before the sterilization treatment (-(dimensionless)).

  In experiments for demonstrating the bactericidal effect, sterilizing experiments are often performed on water in which organic substances are hardly contained, for example, pure water or sterilized physiological saline sprayed with microorganisms. However, it is known that various drainage components are contained in actual drain water. The dirt component contained in the drain water is not constant, and contains organic substances, chloride ions, sodium ions, and the like, which are dirt components in the air. Since these components are known to inhibit sterilization treatment, in order to accurately grasp the sterilization performance of antibacterial agents, obtain drain water on the market or artificially use water equivalent to drain water. It is necessary to use what was prepared in the above as a test sample. The components contained in the drain water vary widely depending on the market, but can be indicated by electric conductivity as one index. The electrical conductivity is the reciprocal of the resistance of water, and shows a higher value as more soil components are contained. When the electrical conductivity of drain water in various markets was actually measured using an electrical conductivity meter (Horiba ES-51), it was in the range of 10 to 150 μS / cm.

The procedure of the sterilization experiment is as follows. Drain water whose generation of slime has been confirmed in the market is sprayed on NB (Nutrient Broth) agar medium (manufactured by Becton Dickinson), colonies grown after 18 hours at 35 ° C. are fished, and electric conductivity is 20 μS / cm. Add microbial cells to the drain water. The initial microorganism count of the drain water at this time was about 10 ⁵ CFU / mL. CFU (Colony Forming Unit) counts the number of colonies grown on the medium and is a unit of the number of microorganisms. To this sample, a borosilicate glass antibacterial agent is added, water is collected 24 hours later, sprayed onto the NB agar medium, and the number of colonies grown on the NB agar medium after 18 hours at 35 ° C. is counted. At this time, the amount of silver ion elution was changed by adjusting the amount of the borosilicate glass antibacterial agent, and experiments were conducted under three conditions of 0.0 mg / L, 1.8 mg / L, and 4.1 mg / L. The silver ion concentration was measured with an ICP (inductively coupled plasma) analyzer.

  Since the survival rate of microorganisms is the ratio of the number of microorganisms to the initial number of microorganisms, the smaller the value, the higher the bactericidal effect, and the closer the value is to 1.0, the smaller the bactericidal effect. In general, a significant antibacterial effect means that 99% of microorganisms are sterilized, that is, the survival rate is 0.01. From this, it can be seen that, in order to obtain a sufficient bactericidal effect, a silver ion elution amount of about 1.5 mg / L or more is required in 24 hours, as shown in FIG. Therefore, it is necessary for the silver ion generating part 1 to have a specification such that the silver ion elution amount is 1.5 mg / L in 24 hours. When a borosilicate glass antibacterial agent was used, 5 g of borosilicate glass antibacterial agent per 1 L of drain water 8 was required.

Next, the silver ion sterilization effect promoting unit 2 will be described.
The silver ion bactericidal effect promoting unit 2 used in the present embodiment is for eluting at least one metal ion other than silver ions (for example, copper, nickel or zinc ions). Although the metal ion to elute is not specifically limited, Since the acceleration effect by a copper ion is especially high, what elutes a copper ion is more preferable. When copper is used as the silver ion sterilization effect promoting part 2, copper is used alone, or metallic copper or copper ions are uniformly contained in a solid material, and when touching water or in water It is desirable to use a material that releases copper as copper ions when dissolved therein. In the present embodiment, a copper plate of phosphorous deoxidized copper made of simple copper is used. However, a copper plate containing the above-described glass tablet may be used.

  FIG. 5 is a graph showing the relationship between the electrical conductivity of drain water 8 and the elution amount of silver ions when a borosilicate glass antibacterial agent is used as the silver ion generator 1 in the air conditioner according to the present embodiment. is there. The horizontal axis of the graph represents the electrical conductivity (μS / cm) of the drain water 8. The vertical axis of the graph represents the silver ion concentration (silver ion elution amount) (mg / L) after 24 hours when 5 g of the silver ion generation unit 1 is charged into 1 L of drain water 8 having each electrical conductivity. . As shown in FIG. 5, the silver ion elution amount is about 4.2 mg / L when the electric conductivity is about 0 μS / cm, whereas it is about 0.25 mg / L when the electric conductivity is about 120 μS / cm. It has decreased to L. From this, it can be seen that the higher the electrical conductivity, the lower the silver ion elution amount. Since a decrease in the elution amount of silver ions means a decrease in sterilization performance, the higher the electric conductivity, the lower the sterilization performance.

In order to demonstrate this, the relationship between electrical conductivity and microbial survival was investigated. FIG. 6 shows the relationship between the electrical conductivity of the drain water 8 in the air conditioner according to the present embodiment and the survival rate after the microorganisms of the drain water 8 are allowed to stand for 8 hours in the presence of the silver ion generator 1. It is a graph which shows. The horizontal axis of the graph represents electrical conductivity (μS / cm), and the vertical axis of the graph represents the survival rate of microorganisms. As silver ion generating part 1, 5g of borosilicate glass antibacterial agent is put into 1L drain water 8 of each electric conductivity. The procedure of the experiment is the same as that of the above-mentioned experiment. A microorganism obtained from drain water is added to a sample of drain water 8 having different electrical conductivity, and 5 g of borosilicate glass antibacterial agent is added to 1 L of drain water 8. Then, the number of microorganisms in the drain water 8 after 8 hours was measured with an NB agar medium. As shown in FIG. 6, the microorganism viability of the drain water 8 is about 10 ⁻⁵ when the electrical conductivity is about 0 μS / cm, but 10 ⁻² when the electrical conductivity is 100 μS / cm. Furthermore, when the electric conductivity is 130 μS / cm, it becomes about 1. Thus, it can be seen that the higher the electrical conductivity, the closer the microorganism survival rate is to 1, and the sterilization effect is reduced.

  5 and 6, when the electrical conductivity of the drain water 8 increases, the amount of elution of silver ions from the silver ion generation unit 1 decreases, so that the sterilization effect of the microorganisms decreases and the sterilization effect of silver ions is sufficiently obtained. It can be seen that there are no conditions.

FIG. 7 shows a case where copper ions are added to drain water 8 having an electric conductivity of 120 μS / cm and 5 g / L of borosilicate glass antibacterial agent is added as silver ion generator 1 in the air conditioner according to the present embodiment. It is a graph which shows the relationship between the copper ion concentration and the survival rate of the microorganisms 8 hours after the drain water 8. The horizontal axis of the graph represents the copper ion concentration (mg / L), and the vertical axis of the graph represents the survival rate of the microorganism. The silver ion generator 1 is set so that the elution amount of silver ions after 24 hours is 0.25 mg / L. As shown in FIG. 7, the survival rate when the copper ion concentration is about 0 mg / L is about 0.5. When the copper ion concentration is 0.01 mg / L or more, the survival rate is lowered, and when the copper ion concentration is in the range of 0.1 to 2.0 mg / L, the survival rate is about 10 ⁻³ and becomes the smallest. When the copper ion concentration increases from 2.0 mg / L, the survival rate gradually increases, and when the copper ion concentration is about 5.0 g / L, the survival rate becomes about 0.5. The survival rate when the copper ion concentration is 0.0 mg / L indicates the survival rate due to the bactericidal effect of only silver ions. From this, it can be seen that the coexistence of silver ions and copper ions provides a synergistic effect of sterilization as compared with the case of only silver ions. From the graph of FIG. 7, the copper ion concentration at which a synergistic effect is obtained is in the range of 0.01 mg / L to 5.0 mg / L, and preferably 0.1 mg / L to 2.0 mg / L. Recognize. Therefore, a higher sterilization effect can be obtained by eluting metal ions (for example, copper ions) from the silver ion sterilization effect promoting unit 2 so as to obtain a concentration at which the above synergistic effect is obtained.

The installation shape at the time of using a copper (phosphorus deoxidized copper) board for the silver ion sterilization effect promotion part 2 is demonstrated. FIG. 8 shows the relationship between the surface area of copper and the amount of drain water 8 required to elute 0.1 mg / L of copper ions in 24 hours with respect to drain water 8 having an electric conductivity of 120 μS / cm. It is a graph. The horizontal axis of the graph represents the amount of drain water (mL), and the vertical axis of the graph represents the copper surface area (cm ² ). As shown in FIG. 8, as the surface area of copper brought into contact with the drain water 8 increases, the copper ion elution amount increases, and the copper surface area at which the copper ion elution amount becomes 0.1 mg / L in 24 hours is about 100 mL. It can be seen that it is 35 cm ² . The relationship between the surface area of copper and the amount of drain water 8 is linear, and is represented by the following formula 1.
Y = 0.35X (Formula 1)
Y: copper surface area (cm ² ), X: amount of drain water 8 (mL)

That is, it is necessary to install copper having a surface area of 35 cm ² for 100 mL of drain water 8. However, since the water level of the drain water 8 is not constant and varies depending on the amount of the drain water 8, the copper installation method needs to correspond accordingly. FIG. 9 is a graph showing an example of the relationship between the water level of the drain water 8 and the amount of the drain water 8. The horizontal axis of the graph represents the drain water level (mm), and the vertical axis of the graph represents the drain water amount (mL). As shown in FIG. 9, in this example, the water level change for every 100 mL of drain water 8 is 5 mm. In such a case, in order to install copper having a predetermined surface area for every 100 mL, a copper plate having a surface area of 35 cm ² is hindered from the drain pan 7 within a height of 5 mm, and the drain pump 4 prevents the drain water 8 from being discharged. It is desirable to install it with no shape. Therefore, it is desirable to install not a flat copper plate but a phosphorus-deoxidized copper mesh or a rolled copper mesh, or a copper plate bent into a pleated shape.

The example of the specific structure of the silver ion sterilization effect promotion part 2 is demonstrated. FIG. 10 is a diagram illustrating an example of the structure of the silver ion sterilization effect promoting unit 2. As shown in FIG. 10, the silver ion sterilization effect promoting portion 2 is formed by bending a flat copper plate 2 a into a pleated shape, and a portion of the drain water 8 having a height of 0 to 5 mm (the height from the bottom surface 7 a of the drain pan 7 is 5 mm). It has a structure installed in The copper plate 2a is bent so that each slope has an angle of 30 ° with respect to the bottom surface 7a. As a result, the slope length of each slope becomes 10 mm, and the total length of the slope is 50 mm on one side and 100 mm on both front and back surfaces by forming a pleated shape with two halves (for 5 slopes). Therefore, by setting the depth in the direction orthogonal to the paper surface of FIG. 10 to 35 mm, the pleated copper plate 2a having a predetermined surface area (35 cm ^{2 in} this example) can be immersed in the drain water 8.

Next, the phenomenon that the bactericidal effect is synergistically improved by the coexistence of silver ions and copper ions will be described.
It is considered that the inactivation mechanism of bacteria (microorganisms) by each metal ion proceeds in the following two stages.
First stage: a process in which metal ions penetrate into the cytoplasm while reacting with cell membranes and cell walls. In that case, a metal ion reacts with a base (for example, thiol group (SH group)) among respiratory chain enzymes existing between a cell membrane and a cell wall on the surface of bacteria (periplasmic space). As a result, the enzyme activity is lost and the bacteria are inactivated. Bacteria are also inactivated by damage to cell membranes and cell walls due to the catalytic effect of metal ions.
Second stage: inactivation process inside cytoplasm. Metal ions that have entered the cytoplasm react with ribosomes that are present in large amounts in the cytoplasm, resulting in a failure of the protein synthesis function. As a result, production of ATP synthase necessary for synthesizing ATP (adenosine triphosphate), which is bioenergy, is stopped, and the cells are inactivated.

  In the inactivation of bacteria by silver ions, the first stage proceeds smoothly, and silver ions penetrate to the vicinity of the center of the cells in a relatively short time. Depending on the bacterium, a large amount of silver ions may penetrate into the center of the bacterium within 30 minutes. On the other hand, inactivation of bacteria by copper ions, the first stage is difficult to proceed, and cell membranes and cell walls are damaged by some other means (for example, photocatalytic active oxygen or free chlorine group of sodium hypochlorite). ) To promote the first stage.

  On the other hand, in the second stage, both silver ions and copper ions cause inactivation of protein synthesis function and abnormal cell morphology over 12 to 24 hours. This reaction rate varies depending on bacteria, and copper ions have a higher bactericidal effect and may have a faster reaction rate.

  From these facts, the synergistic bactericidal effect of silver ions and copper ions is that, in the first stage, silver ions mainly damage cell membranes and cell walls, and in the second stage, both silver ions and copper ions are in the cytoplasm. It is a mechanism that penetrates, damages the inside of the cytoplasm, and inactivates cells.

  In the graph shown in FIG. 7, the bactericidal effect is greatly improved when the silver ion concentration and the copper ion concentration are approximately the same. This is thought to be because silver ions penetrated the cell membrane and cell wall, and copper ions penetrated into the cytoplasm from the damaged part to enhance the bactericidal effect. On the other hand, when the silver ion concentration is lower than the copper ion concentration, the bactericidal effect is reduced even if a large amount of copper ion is present, the penetration of silver ions into the cell membrane and cell wall becomes rate-limiting, and the bactericidal effect is reduced. This is probably because the copper ions present more than the silver ions inhibit the contact between the silver ions, the cytoplasm, and the cell wall. From the above, it is preferable that the copper ions eluted from the silver ion sterilization effect promoting unit 2 have a concentration that does not exceed the silver ion concentration eluted from the silver ion generating unit 1.

  The degree of action of silver ions and copper ions varies depending on the microorganism species forming the slime. When the contribution of the sterilization effect by silver ions is larger, the contribution of silver ion elution promotion is greater, and when there is a microorganism whose inactivation is promoted by copper ions, the action of copper ions in the second stage Sometimes it can be dramatic.

Next, the positional relationship between the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 will be described.
It is known that when a different kind of metal exists, a metal having a high ionization tendency dissolves and a small metal precipitates. Silver and copper have a lower ionization tendency. Therefore, silver ions are precipitated as silver simple substance as shown in the following formula 2 by the electric action when copper simple substance is present, and copper ions are dissolved. On the other hand, with silver ions and copper ions, the sterilization effect is higher for silver ions at the same concentration. When the silver ion generating part 1 and the silver ion bactericidal effect promoting part 2 are installed in contact with each other, even if silver is dissolved as silver ions from the silver ion generating part 1, silver ions are reacted before reacting with microorganisms. Since it contacts with the metal of the sterilization effect promoting part 2 and is replaced with silver alone, the sterilization effect is lowered. Therefore, it is preferable to install the silver ion generating part 1 and the silver ion sterilization effect promoting part 2 without contacting each other.
2Ag ⁺ + Cu → Ag + Cu ²⁺ (Formula 2)

  FIG. 11 is a graph showing the relationship between the distance between the silver ion generation unit 1 and the silver ion sterilization effect promoting unit 2 and the antibacterial effect in the air conditioner according to the present embodiment. The horizontal axis of the graph represents the distance (cm) between the silver ion generating part 1 and the silver ion sterilization effect promoting part 2, that is, the copper plate. 0.0 cm on the horizontal axis indicates that the silver ion generating part 1 and the silver ion sterilizing effect promoting part 2 are installed in contact with each other. The vertical axis of the graph represents the ratio of the bactericidal effect of drain water 8 to microorganisms. In order to express the relative magnitude of the bactericidal effect, the reciprocal of the survival rate of the microorganisms after 24 hours was defined as the bactericidal performance, and the ratio of the silver ion generating unit 1 alone to the bactericidal performance was defined as the ratio of the bactericidal effect. That is, the ratio of the sterilizing effect of the silver ion generating part 1 alone is 1.0, and when the ratio of the sterilizing effect is larger than 1.0, the sterilizing effect is higher than that of the silver ion generating part 1 alone. When the ratio is less than 1.0, it indicates that the sterilization effect by the silver ion generating part 1 alone is lower. As shown in FIG. 11, when the distance between the silver ion generation part 1 and the silver ion sterilization effect promoting part 2 is 0.0 cm, that is, when both are in contact, the ratio of the sterilization effect is about 0.067. It is lower than the sterilizing effect of the silver ion generator 1 alone. On the other hand, if the silver ion generation part 1 and the silver ion sterilization effect promoting part 2 are installed without contact (distance is greater than 0.0 cm), the sterilization effect ratio increases to about 6.67, and then the sterilization effect is maintained. It was done. Therefore, it is desirable that the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 be installed apart from each other without contacting each other.

  FIG. 12 is a plan view corresponding to FIG. 3, and is a diagram illustrating another example of the positional relationship between the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 in the air conditioner according to the present embodiment. In FIG. 12, two positions (reference numerals 2 (1) and 2 (2) in the figure) are illustrated as the installation positions of the silver ion sterilization effect promoting unit 2. The silver ions eluted from the silver ion generator 1 are always replaced and deposited when the metal ions eluted from the silver ion bactericidal effect promoting portion 2 (metal ions having a higher ionization tendency than silver) are present. Therefore, it is preferable that the installation positions of the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 are not brought into contact with each other and separated as much as possible as shown in FIG.

Next, the installation positions in the height direction of the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 will be described with reference to FIG.
When the drain pump 4 is driven during the cooling operation of the air conditioner, since the drain water 8 is discharged by the drain pump 4, the water level of the drain water 8 is lowered to the height of the suction port 4 a of the drain pump 4. The water level of the drain water 8 at this time is defined as a lower limit water level 17. In addition, when the cooling operation is stopped and the drain pump 4 is driven, the water level of the drain water 8 is also the lower limit water level 17. On the other hand, when the cooling operation is stopped and the drain pump 4 is stopped, a part of the drain water 8 pumped up by the drain pump 4 returns to the drain pan 7. It rises above the lower limit water level 17 of the hour. The water level of the drain water 8 at this time is defined as an upper limit water level 18. This is because the drain water 8 pumped up by the drain pump 4 to the in-machine piping or the attached drain pipe returns to the suction port 4 a side when the drain pump 4 stops. That is, the water level of the drain water 8 after the drain pump 4 is stopped rises from the lower limit water level 17 by an amount corresponding to the rise in the water level due to the return water from the drain pump 4. The upper limit water level 18 can be specified from the amount of return water when the drain pump 4 is stopped if a relational expression between the level of the drain water 8 and the amount of the drain water 8 is calculated in advance.

  When an antibacterial agent such as the silver ion generator 1 is installed on the bottom surface of the drain pan 7, the installed antibacterial agent is always immersed in the drain water 8, and always exhibits a sterilizing effect even during the cooling operation. . During the cooling operation, drain water 8 is generated one after another in the heat exchanger 6, and the drain water 8 is drained by the drain pump 4, so that the drain water 8 in the drain pan 7 flows without stagnation. Moreover, since the drain water 8 generated during the cooling operation is condensed water generated on the surface of the heat exchanger 6, it is as low as 15 ° C. or lower. The temperature at which general microorganisms propagate is 25 ° C. or more, and a temperature of 15 ° C. or less is not an environment in which microorganisms easily propagate. Further, since the drain water 8 always flows during the cooling operation, the antibacterial agent also flows out, which is not efficient. Therefore, the silver ion generation unit 1 is not immersed in the drain water 8 at all times, but is installed at a position where it is immersed in the drain water 8 only when the cooling operation is stopped (when the drain pump 4 is stopped). Can exhibit a bactericidal effect.

  As shown in FIG. 2, the lower limit water level 17 is a water level when the drain pump 4 is draining during the cooling operation, and has the same height as the suction port 4 a of the drain pump 4. The upper limit water level 18 is a water level when the drain pump 4 is stopped and the return water (drain water 8 being pumped up in the drain pipe) is stored in the drain pan 7. By installing the silver ion generation part 1 and the silver ion sterilization effect promotion part 2 with the lower limit water level 17 and the upper limit water level 18 as the reference of the height position, the antibacterial agent is eluted only at the time of cooling operation in which microorganisms are likely to propagate. Is possible. For example, if the lower ends of both the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 are installed at a height between the lower limit water level 17 and the upper limit water level 18, the silver ion generation unit 1 and the silver ion sterilization effect promotion The life of the part 2 can be extended.

  FIG. 13 is a graph showing the influence of the elution state of copper ions on the bactericidal effect of silver ions eluted from the silver ion generator 1. FIG. 13 compares the ratio of the bactericidal effect under four conditions. The horizontal axis direction of the graph is, in order from the left, when (1) the silver ion generation part 1 and the silver ion bactericidal effect promotion part 2 (copper plate) are used (silver ion + copper plate), (2) the silver ion generation part 1 When immersed in drain water 8 in which copper ions are dissolved (addition of silver ions + copper ions), (3) In the case of only silver ion generation part 1 (only silver ions), (4) In the case of only copper ions (only copper ions) ), And each condition. The vertical axis of the graph represents the ratio of the bactericidal effect when the bactericidal effect (condition (3)) of the silver ion generator 1 alone is 1. The larger the ratio of sterilization effect, the higher the sterilization performance. That is, when the ratio of the bactericidal effect is larger than 1, it indicates that the bactericidal effect is higher than that of the silver ion generating part 1 alone, and when the ratio of the bactericidal effect is smaller than 1, silver It represents that the bactericidal effect is lower than that of the ion generator 1 alone.

  As shown in FIG. 13, when copper ions are gradually dissolved in the drain water 8 from the silver ion sterilization effect promoting portion 2 (condition (1)) and when copper ions are dissolved in the drain water 8 in advance (condition ( The ratio of the bactericidal effect of the drain water 8 to the microorganisms in 2)) and 3.0 is 3.0 and 6.67, respectively. The sterilizing effect under the conditions (1) and (2) is higher than the sterilizing effect of the silver ion generating part 1 alone, but the silver ion generating part 1 is immersed in drain water 8 in which copper ions are first dissolved. The sterilizing effect under the condition (2) was more than twice as high as the sterilizing effect under the condition (1).

In general, the redox potential affects the dissolution of a substance. A higher redox potential promotes ion dissolution from the substance into water. Therefore, elution of silver ions from the silver ion generator 1 is faster when the redox potential is higher. If other water qualities are equivalent, the oxidation-reduction potential is determined by the metal ion concentration, that is, the copper ion concentration in this case, from the following equation 3 (Nernst equation).
E = E ₀ + (RT / nF) ln [metal ion concentration] (Formula 3)
E: redox potential, E ₀ : standard redox potential, R: gas constant (8.3145 JK ⁻¹ mol ⁻¹ ), T: absolute temperature (K), n: number of electrons involved in the reaction per atom, F: Faraday constant (9.6485 × 10 ⁴ C / mol), metal ion concentration: mol / L

  From Equation 3, the oxidation-reduction potential E is higher when copper ions are present at a predetermined concentration (for example, 0.1 mg / L) than when no metal ions are present. From this, when the copper ions are dissolved first, the elution of silver ions is further promoted, so that the bactericidal effect is also increased.

  Therefore, it is desirable that copper ions be dissolved as ions before elution of silver ions from the silver ion generator 1 occurs. Therefore, the silver ion sterilization effect promoting unit 2 is not always immersed in the return water after stopping the drain pump 4 and eluting the copper ions as in the case of the silver ion generating unit 1, but is always immersed in the drain water 8 and drained. It is desirable to install at a position where copper ion elution into water 8 occurs. Specifically, the silver ion sterilization effect promoting unit 2 is installed in the drain water flow path 15 that flows from the heat exchanger 6 to the drain pump 4. Moreover, as shown in FIG. 2, the silver ion sterilization effect promotion part 2 becomes the water level in the running water of the drain water 8 so that copper ions dissolve even while the drain water 8 is discharged by the drain pump 4. It is desirable to install so as to be immersed in a portion below the lower limit water level 17.

  From the above, based on the lower limit water level 17 (the height of the suction port 4a) and the upper limit water level 18 (the water level height raised by the return water) of the drain pan 7, the silver ion generating part 1 and the silver ion sterilizing effect promoting part 2 The desired height position of the is summarized as follows.

  It is desirable that the lower end of the silver ion generation unit 1 is disposed at a height position above the lower limit water level 17 and the same as or below the upper limit water level 18. This is because the silver ion generator 1 is not immersed in the drain water 8 during the cooling operation where the microorganisms are difficult to propagate (when the drain pump 4 is operated), and when the cooling operation is easy to propagate the microorganisms (when the drain pump 4 is stopped). This is because the silver ion generator 1 is immersed in the drain water 8 only.

  It is desirable that at least a part (for example, the lower end) of the silver ion sterilization effect promoting portion 2 is disposed at the same height as the lower limit water level 17 or at a lower height position. This is because the silver ion sterilization effect promoting portion 2 is immersed in the drain water 8 during the cooling operation (during the drain pump 4 operation).

  The operation of the air conditioner according to the present embodiment will be described with reference to FIG. FIG. 14 is an explanatory diagram showing an example of the operation (situation) of the air conditioner according to the present embodiment. The left column of FIG. 14 shows the operating condition of the air conditioner, the middle column shows the water level of the drain water 8, and the right column shows the drain pan sterilization mechanism 3 (the silver ion generating part 1 and the silver ion sterilizing effect promotion). Part 2) is shown.

  When the cooling operation of the air conditioner is started, moisture in the air condenses on the surface of the heat exchanger 6, and drain water 8 flows out to the drain pan 7. At this time, the water level of the drain water 8 in the drain pan 7 is lower than the lower limit water level 17, but if a part of the silver ion sterilization effect promoting part 2 is immersed in the drain water 8, metal ions (in this example, copper ions) ) Elutes into the drain water 8. When the water level rises to the suction port 4a of the drain pump 4, the drain pump 8 starts to discharge the drain water 8 based on the detection signal of the water level sensor 5, and a certain amount of drain water 8 continues to be discharged (FIG. 14). "Cooling operation and drain pump operation start"). The water level of the drain water 8 at this time is maintained at the lower limit water level 17. Since the drain water 8 below the suction port 4a is not sucked up, the elution of copper ions from the silver ion sterilization effect promoting portion 2 continues. That is, in the drain pan sterilization mechanism 3, only the silver ion sterilization effect promoting part 2 is immersed in the drain water 8, and only the copper ions are eluted in the drain water 8.

  Thereafter, when the cooling operation of the air conditioner is stopped and the drain pump 4 is stopped (“cooling operation / drain pump operation stop” in FIG. 14), the water accumulated in the drain pump 4 or the like is reduced by gravity. Thus, the drain pan 7 is returned to and the water level of the drain water 8 rises. That is, the water level of the drain water 8 becomes a water level (upper limit water level 18) that is raised by the return water. At this time, both the silver ion generation part 1 and the silver ion sterilization effect promoting part 2 of the drain pan sterilization mechanism 3 are immersed in the drain water 8. In the drain water 8, since copper ions have already eluted from the silver ion sterilization effect promoting portion 2, the oxidation-reduction potential has risen, so that silver ions are rapidly eluted from the silver ion generating portion. As a result, sterilization of microorganisms in the drain water 8 is performed regardless of the electrical conductivity of the drain water 8 due to the sterilization effect of silver ions.

As the silver ion sterilization effect promoting part 2, an antibacterial agent containing copper may be used. In that case, zirconium phosphate, zeolite, hydroxyapatite, silica gel, water-soluble glass, etc., each carrying copper, can be used. Since it is water-soluble glass that can elute copper ions and prevent the generation of microorganisms over a long period of time, it is preferable to use water-soluble glass. The above-described zirconium phosphate supporting copper, zeolite, or the like may be added to water-soluble glass. Examples of the water-soluble glass that elutes copper ions include phosphosilicate glass, borosilicate glass, borate glass, phosphate glass, and soda glass. As the water-soluble glass in the present embodiment, phosphosilicate glass or borosilicate glass is preferable, and SiO ₂ is 15 to 60% in mass ratio in terms of oxide; from Li ₂ O, Na ₂ O and K ₂ O. At least one selected from the group consisting of 10 to 40%; CuO 0.1 to 5%; P ₂ O ₅ 10 to 50% and / or B ₂ O ₃ 5 to 50%; MgO, CaO, 0 to 20% of at least one selected from the group consisting of SrO and BaO; 0 to 20% of at least one selected from the group consisting of Al ₂ O ₃ , ZnO, CeO ₂ , ZrO ₂ and TiO ₂ Most preferred is water soluble glass. These can be prepared to produce a copper antibacterial agent that elutes the required amount of copper ions. Moreover, glass components other than this can also be included arbitrarily.

  FIG. 15 is a graph comparing the ratio of the sterilization effect depending on whether or not the drain water 8 is stirred in the air conditioner according to the present embodiment. Here, a copper plate is used as the silver ion sterilization effect promoting unit 2, the silver ion generating unit 1 and the silver ion sterilizing effect promoting unit 2 are installed without being in contact with each other, and the drain pump 4 is driven after 4 hours, and the drain water The ratio of the bactericidal effect after 8 hours depending on whether or not 8 was stirred was compared. The stirring of the drain water 8 by driving the drain pump 4 means the stirring of the drain water 8 by the return water when the drain pump 4 is stopped. That is, as described above, when the drain pump 4 is stopped, part of the drain water 8 pumped up by the drain pump 4 returns to the drain pan 7. At this time, the drain water 8 in the drain pan 7 is stirred. As shown in FIG. 15, the bactericidal effect when stirring was performed increased 7.5 times compared with the case where stirring was not performed. From this, when performing drain pan 7 sterilization in the silver ion generation part 1 and the silver ion sterilization effect promotion part 2, the sterilization effect can be further improved by stirring the drain water 8 by the drain pump 4. Recognize.

Below, the Example which performed the disinfection process of the drain water 8 using the air conditioner which concerns on this Embodiment is described.
[Example 1]
In Example 1, in order to confirm the bactericidal effect with respect to the microorganisms on the drain pan 7, Pseudomonas bacteria are put into the drain water 8 of the drain pan 7, and the bactericidal treatment under each condition (experimental conditions 1, 2 and comparative conditions 1 to 4) is performed. The effect was investigated. FIG. 16 is a diagram illustrating experimental conditions 1 and 2 and comparative conditions 1 to 4 in Example 1. In FIG. 16, the electrical conductivity of the drain water 8 under each condition and the presence / absence of installation of the silver ion generation unit 1 and the silver ion sterilization effect promotion unit 2 (“○” is installed, “×” is not installed). Show. Experimental conditions 1 and 2 are conditions corresponding to the air conditioner according to the present embodiment, and comparison conditions 1 to 4 are conditions for comparison with the air conditioner according to the present embodiment. With respect to the experimental conditions 1 and 2 and the comparative conditions 1 to 4 shown in FIG. 16, sterilization treatment was performed by the following method.

In accordance with the conditions shown in FIG. 16, 500 mL of drain water 8 (Pseudomonas fungus is 10 ⁶ CFU / mL) in which the silver ion generation unit 1 and / or the silver ion bactericidal effect promoting unit 2 is installed in each drain pan 7 and the electric conductivity is adjusted. Was adjusted so that the bactericidal effect against Pseudomonas bacteria was verified. As the silver ion generator 1, 2.5 g (equivalent to 5.0 g / L) of borosilicate glass antibacterial agent was installed, and the silver ion elution amount was adjusted to 0.25 mg / L in 24 hours. As silver ions bactericidal effect promoting unit 2, it was placed the copper plate 175cm ² (35 cm ^2/100 mL or equivalent) in the surface area.

  FIG. 17 is a graph showing experimental results in Example 1. The horizontal axis of the graph represents the immersion time (hour), and the vertical axis represents the number of microorganisms (CFU / mL). In FIG. 17, the experimental results of comparative conditions 1 to 4 are also shown together with the experimental results of experimental conditions 1 and 2 indicating the effect of the sterilization treatment by the air conditioner according to the present embodiment. As shown in FIG. 17, in the experimental conditions 1 and 2, the number of microorganisms decreased with the lapse of the immersion time, and decreased by 3 digits or more after 8 hours. On the other hand, in comparison condition 1 to 4 in comparison conditions 1 to 4, the number of microorganisms decreased with the lapse of immersion time and decreased by about 3 digits after 8 hours, but in other comparison conditions 1, 3, and 4, the number of microorganisms The decrease in was not confirmed.

  From the above results, when both the silver ion generating part 1 and the silver ion sterilization effect promoting part 2 exist as in the experimental conditions 1 and 2, the drain water 8 It turns out that sterilization of microorganisms is performed effectively. On the other hand, in the comparison condition, when only the silver ion generating part 1 is present, the bactericidal effect is obtained when the electrical conductivity of the drain water 8 is low, but the bactericidal effect cannot be obtained when the drain water 8 is high. I understand that. Moreover, when only the silver ion sterilization effect promotion part 2 exists, it turns out that a sterilization effect is not acquired irrespective of the electrical conductivity of the drain water 8. FIG.

Embodiment 2. FIG.
An air conditioner according to Embodiment 2 of the present invention will be described. In this embodiment, differences from the first embodiment will be mainly described, and the same functions and configurations as those of the first embodiment will be described using the same reference numerals.

  FIG. 18 is a schematic cross-sectional view showing a configuration in the vicinity of the drain pan 7 of the air conditioner according to the present embodiment. The configuration of the air conditioner according to the present embodiment is the same as that of the air conditioner according to Embodiment 1 shown in FIG. In the present embodiment, the silver ion sterilization effect promoting unit includes an electrode pair 9 having a pair of a plate-like voltage electrode 13 and a ground electrode 14, and a power supply 10 that applies a voltage between the voltage electrode 13 and the ground electrode 14. And is different from the first embodiment. The power supply 10 is connected to a water level sensor 5 installed in the drain pan 7, and a detection signal from the water level sensor 5 is output to a control unit (microcomputer) (not shown) provided in the power supply 10. The voltage electrode 13 is an electrode including at least one kind of metal other than silver. The voltage electrode 13 and the ground electrode 14 are arranged in the drain pan 7 with a predetermined interval. The voltage electrode 13 and the ground electrode 14 are both installed such that their lower ends are located at the same level as or below the lower limit water level 17.

  As the material of the voltage electrode 13, for example, copper, nickel, zinc, or the like can be used. However, since the acceleration effect by copper ions is particularly high, it is preferable to use copper. The shape of the voltage electrode 13 can be various shapes such as a disc shape, a rod shape, or a line shape in addition to a flat plate shape. The side surface of the voltage electrode 13 may be covered with an insulator. Further, the size of the voltage electrode 13 is not particularly limited. If a material having a large surface area such as a mesh shape is used, there is an advantage that metal ions can be efficiently eluted with a small applied voltage. The power source 10 is a DC power source, and applies a DC voltage continuously with the voltage electrode 13 as an anode and the ground electrode 14 as a cathode.

The ground electrode 14 will be described below.
The ground electrode 14 undergoes electrolysis and generates hydroxide ions (OH ⁻ ) according to the following formula 4. For this reason, the pH in the vicinity of the ground electrode 14 rises to around 11.
2H ₂ O + 4e ⁻ → H ₂ + 4OH ⁻ (Formula 4)

  For this reason, it is preferable to use a metal such as platinum (Pt) or gold (Au) that is resistant to a pH of around 13 as the material of the ground electrode 14. However, since platinum and gold are expensive, the ground electrode 14 may be titanium (Ti) plated with platinum or the like.

  Alternatively, the ground electrode 14 may be made of the same material as the metal used in the voltage electrode 13, and the metal may be actively dissolved from both electrodes while alternately applying voltage pulses between the electrodes. Good. Since metal ions can be eluted from both the voltage electrode 13 and the ground electrode 14, there is an advantage that the life of each electrode can be extended.

  The shape of the ground electrode 14 can be various shapes such as a disc shape, a rod shape, or a line shape in addition to a flat plate shape. Further, similarly to the voltage electrode 13, the side surface of the ground electrode 14 may be covered with an insulator. Further, the size of the ground electrode 14 is not particularly limited. Further, when titanium or the like is used for the ground electrode 14, it is desirable to use a material having a large surface area such as a mesh shape.

  Here, the ground electrode 14 is an electrode that is grounded as the name suggests. For this reason, the polarity of the voltage applied to the voltage electrode 13 and the ground electrode 14 shown in the present embodiment and the following embodiments indicates the polarity with respect to the ground electrode 14.

  The gap between the voltage electrode 13 and the ground electrode 14 may be 1 to 50 mm, preferably 5 to 20 mm.

The amount of metal ions dissolved in the drain water 8 can be calculated from the theoretical formula (Faraday's law) shown in the following formula 5. For example, when 0.1 mg / L of copper ions is to be dissolved in 0.5 L of drain water 8, the voltage electrode 13 is used as an anode and the ground electrode 14 is used as a cathode so that the current flows through the voltage electrode 13 at a current of 1 mA for about 160 seconds. It can be seen that a voltage may be applied.
A = Q / Z / U / X = I × M × t / Z / U / X (Formula 5)
A: Metal ion concentration (mg / L) to elute, Q: Electric quantity (C), I: Current flowing between electrodes (mA), Z: Faraday constant (9.65 × 10 ⁴ C / mol), M: Atomic weight (copper: 63.5), t: current application time (s), U: amount of drain water 8 (L), X: ionic valence

  That is, if the amount of drain water 8 is known in addition to the current flowing between the electrodes and the time during which the current is applied, the amount of copper ions dissolved in the drain water 8 is in the range of 0.1 to 2 mg / L. Means that you can.

  The water level sensor 5 will be described. The water level sensor 5 is preferably a sensor that converts the water level to current and outputs it. For example, in a float type water level sensor, the float moves up and down with the water level according to the principle of buoyancy, and the reed switch is activated by the magnet in the float to convert the water level into current and output it. Specifically, the float-type water level sensor includes a float (floating) and a reed switch and a resistor inside a stem (shaft) where the float is installed. By closing the contact of the reed switch at the position where the magnet in the float moves due to fluctuations in the water level, the water level change is detected as a resistance change, and the resistance-current converter outputs the water level as a DC current signal. As the water level sensor 5, for example, a current type water level sensor may be used. The current type water level sensor includes a common electrode and a detection electrode corresponding to the water level facing the common electrode. A voltage is applied between the common electrode and the detection electrode, and when there is drain water 8 between the electrodes, a predetermined current (for example, 50 mA) flows through the drain water 8, so that the current is detected. At that water level, it is determined that there is water. On the other hand, when the predetermined current does not flow, it is determined that there is no water. The current water level can be estimated by determining the presence or absence of water at each water level. If the relational expression between the water level of the drain water 8 and the amount of the drain water 8 is calculated from the shape of the drain pan 7 in advance, the amount of the drain water 8 is calculated by converting the current value output from the water level sensor 5 into the water level. it can.

A method for controlling the elution of copper ions by the water level detected by the water level sensor 5 will be described.
When it is desired to control the copper ion concentration of the drain water 8 to 0.1 mg / L, if the amount of the drain water 8 can be grasped by the water level sensor 5, the necessary amount of copper ions corresponding to the amount of the drain water 8 is expressed by the following formula 6. Can be represented.
B = C × V (Formula 6)
B: Required copper ion amount (mg), C: Copper ion concentration in drain water 8 to be obtained (mg / L, 0.1), V: Amount of drain water 8 (L)

  The amount of electricity required to dissolve the copper ion amount B can be calculated from Equation 5 above. By determining the amount of drain water 8 from the current value output from the water level sensor 5 and further determining the current I flowing through the electrodes and the time t during which the current is applied, appropriate copper ions are generated at the electrode pair 9. Is possible.

  The operation of the air conditioner according to the present embodiment will be described with reference to FIG. FIG. 19 is an explanatory diagram showing an example of the operation (situation) of the air conditioner according to the present embodiment. The left column of FIG. 19 shows the operating condition of the air conditioner, the middle column shows the water level of the drain water 8, and the right column shows the drain pan sterilization mechanism (the silver ion generating unit 1 and the silver ion sterilizing effect promoting unit). The state of (electrode pair 9 and power supply 10)) is shown.

  When the cooling operation is started, moisture in the air condenses on the surface of the heat exchanger 6, and the drain water 8 flows out to the drain pan 7. The drain water 8 remains in the drain pan 7 until it reaches the height of the suction port 4 a of the drain pump 4. When the water level rises to the height of the suction port 4a of the drain pump 4 (lower limit water level 17), the drain water 8 starts to be discharged by the drain pump 4, and a certain amount of drain water 8 continues to be discharged ("cooling operation" in FIG. 19).・ Drain pump operation started ”). The water level of the drain water 8 at this time is maintained at the lower limit water level 17. Therefore, the silver ion generating part 1 is not immersed in the drain water 8, and silver ions are not eluted. Further, since no voltage is applied to the electrode pair 9, copper ions are not eluted.

  When the cooling operation is stopped and the drain pump 4 is stopped (“cooling operation / drain pump operation stop” in FIG. 19), the water level of the drain water 8 on the drain pan 7 increases by the amount of the return water. The water level at that time is the upper limit water level 18. The water level at that time is detected by the water level sensor 5, and a required amount of copper ions is generated from the voltage electrode 13 of the electrode pair 9 according to the water level by the control of the control unit that controls the power supply 10 (dissolution by electric action). On the other hand, the silver ion generator 1 is immersed in the drain water 8 when the water level rises due to the return water. In the drain water 8 from which copper ions are eluted, elution of silver ions from the silver ion generator 1 occurs promptly. As a result, the elution of silver ions in the presence of copper ions and the sterilization in the coexistence of silver ions and copper ions can provide a sterilizing effect on the microorganisms of the drain water 8 regardless of the electrical conductivity of the drain water 8.

  According to such a configuration, the copper ion is immediately dissolved with respect to the minimum amount of drain water 8, and then the silver ion dissolves quickly, so the amount of copper ion generated is suppressed as much as possible. An unprecedented remarkable effect that the sterilizing effect of the drain water 8 can be maintained high is obtained.

  In the present embodiment, a level sensor that quantitatively measures the water level is used as the water level sensor 5. However, when there is little change in daily use conditions, the presence or absence of drain water 8 is detected by using a switch that detects and outputs the presence or absence of water instead of a level sensor that quantitatively measures the water level. May be operated. Further, without using the water level sensor 5 itself, for example, a table that compares the operation status and the water level of the drain water 8 is created and stored in the control unit, so that the water level is determined from the operation status. The electrode pair 9 may be operated.

Embodiment 3 FIG.
An air conditioner according to Embodiment 3 of the present invention will be described. In this embodiment, the difference from Embodiment 2 will be mainly described, and the same functions and configurations will be described using the same reference numerals.

  FIG. 20 is a schematic cross-sectional view showing a configuration in the vicinity of the drain pan 7 of the air conditioner according to the present embodiment. The structure of the air conditioner according to the present embodiment is the same as that of the air conditioner of the second embodiment shown in FIG. In the present embodiment, the silver ion generation unit includes an electrode pair 11 having a pair of the voltage electrode 19 and the ground electrode 20, and a power supply 12 that applies a voltage between the voltage electrode 19 and the ground electrode 20. This is different from the second embodiment. The voltage electrode 19 is a metal electrode (metal member) made of silver or containing silver. The voltage electrode 19 and the ground electrode 20 are arranged in the drain pan 7 with a predetermined interval. Similarly, the voltage electrode 13 and the ground electrode 14 of the electrode pair 9 are arranged in the drain pan 7 with a predetermined interval. Similar to the second embodiment, the voltage electrode 13 and the ground electrode 14 are both installed such that the lower ends thereof are positioned at the same level as or below the lower limit water level 17. On the other hand, the voltage electrode 19 and the ground electrode 20 are both installed such that the lower ends thereof are located above the lower limit water level 17 and the same as or below the upper limit water level 18.

  The electrode pair 11 will be described below. The material of the voltage electrode 19 is not particularly limited as long as it is silver or an alloy containing silver. The shape of the voltage electrode 19 can also be various shapes such as a flat plate shape, a disk shape, a rod shape, or a linear shape. The side surface of the voltage electrode 19 may be covered with an insulator. Further, the size of the voltage electrode 19 is not particularly limited. If a material having a large surface area such as a mesh shape is used, there is an advantage that silver ions can be eluted with a small applied voltage.

  Moreover, it is good also as a structure which uses the silver used by the voltage electrode 19 as a material of the ground electrode 20, and melt | dissolves a metal actively from both electrodes, applying a voltage pulse alternately between both electrodes. Since silver ions can be eluted from both the voltage electrode 19 and the ground electrode 20, there is an advantage that the life of each electrode can be extended.

  The shape of the ground electrode 20 can be various shapes such as a disc shape, a rod shape, or a line shape in addition to a flat plate shape. Further, similarly to the voltage electrode 19, the side surface of the ground electrode 20 may be covered with an insulator. Further, the size of the ground electrode 20 is not particularly limited. When titanium or the like is used for the ground electrode 20, it is desirable to use a material having a large surface area such as a mesh shape.

  The gap between the voltage electrode 19 and the ground electrode 20 may be 1 to 50 mm, preferably 5 to 20 mm.

  The amount of silver ions dissolved in the drain water 8 can be calculated from the theoretical formula (Faraday's law) shown in Formula 5 above. For example, when 1 mg / L of silver ions is to be dissolved in 0.5 L of drain water 8, if the current value flowing through the voltage electrode 19 is 1 mA, the voltage electrode 19 It can be seen that a DC voltage may be applied with 19 as an anode and the ground electrode 20 as a cathode.

  The operation of the air conditioner according to the present embodiment will be described with reference to FIG. FIG. 21 is an explanatory diagram showing an example of the operation (situation) of the air conditioner according to the present embodiment. The left column of FIG. 21 shows the operating condition of the air conditioner, the middle column shows the water level of the drain water 8, and the right column shows the drain pan sterilization mechanism (silver ion generator (electrode pair 11 and power source 12)). And the situation of the silver ion bactericidal effect promotion part (electrode pair 9 and power supply 10) is shown.

  When the cooling operation is started, moisture in the air condenses on the surface of the heat exchanger 6, and the drain water 8 flows out to the drain pan 7. The drain water 8 remains in the drain pan 7 until it reaches the height of the suction port 4 a of the drain pump 4. When the water level rises to the height of the suction port 4a of the drain pump 4 (lower limit water level 17), the drain water 8 starts to be discharged by the drain pump 4, and the drain water 8 continues to be discharged ("cooling operation / drain pump in FIG. 21" start operation"). The water level of the drain water 8 at this time is maintained at the lower limit water level 17. In this example, when the drain water level is at the lower limit water level 17, no voltage is applied to either the electrode pair 9 or the electrode pair 11. Therefore, neither copper ions nor silver ions are eluted in the drain water 8.

  When the cooling operation is stopped and the drain pump 4 is stopped ("cooling operation / drain pump operation stop" in FIG. 21), the return water accumulated in the drain pump 4 falls to the drain pan 7, and the amount of the return water Only the water level of the drain water 8 on the drain pan 7 rises. The water level at that time is the upper limit water level 18. The water level at that time is detected by the water level sensor 5, and a required amount of copper ions is generated from the voltage electrode 13 of the electrode pair 11 according to the water level (dissolution by electric action). On the other hand, the electrode pair 11 is immersed in the drain water 8 when the water level rises due to the return water. In the drain water 8 from which copper ions are eluted, silver ions are immediately eluted from the voltage electrode 19 (dissolution by electric action). As a result, by elution of silver ions in the presence of copper ions and sterilization in the coexistence of silver ions and copper ions, a sterilizing effect on the microorganisms of the drain water 8 can be obtained regardless of the electrical conductivity of the drain water 8.

  According to such a configuration, after the copper ions are dissolved in the drain water 8, the silver ions are rapidly dissolved only in the return water to be sterilized. Therefore, the generated amounts of both the copper ions and the silver ions are reduced as much as possible. After suppressing, the outstanding effect that the sterilization effect of drain water 8 can be made high is acquired.

  FIGS. 22A to 22D are diagrams schematically illustrating an example of the configuration of the electrode pairs 9 and 11 in the present embodiment. In the air conditioner shown in FIG. 20, as shown in FIG. 22A, an electrode pair 9 for generating copper ions and an electrode pair 11 for generating silver ions are provided independently of each other. However, as shown in FIGS. 22B to 22D, at least some of the electrodes can be shared.

  In the example shown in FIG. 22B, an electrode group 11 a including a copper voltage electrode 13, a silver voltage electrode 19, and a common ground electrode 14 is provided. In this example, the power source 12a is also shared. That is, the power source 12 a can apply a voltage between the voltage electrode 13 and the ground electrode 14, and can also apply a voltage between the voltage electrode 19 and the ground electrode 14. In this case, a voltage is first applied by the power source 12a using the copper voltage electrode 13 as an anode and the ground electrode 14 as a cathode, and after a required amount of copper ions is dissolved in the drain water 8, the silver voltage electrode 19 is used as an anode. A voltage is applied using the ground electrode 14 as a cathode, and silver ions are dissolved in the drain water 8. Thereby, the effect similar to the electrode structure shown to Fig.22 (a) can be acquired.

  In the example shown in FIG. 22C, the ground electrode 14 is further omitted from the configuration of FIG. 22B, and an electrode pair 11b including a copper voltage electrode 13 and a silver voltage electrode 19 is provided. Yes. In this case, a voltage is first applied by the power source 12 b using the copper voltage electrode 13 as an anode and the silver voltage electrode 19 as a cathode, and a required amount of copper ions is dissolved in the drain water 8. Thereafter, a voltage is applied using the silver voltage electrode 19 as an anode and the copper voltage electrode 13 as a cathode to dissolve silver ions in the drain water 8. Thereby, the effect similar to the electrode structure shown to Fig.22 (a) can be acquired.

  In the example shown in FIG. 22 (d), the voltage electrode 13 is further omitted from the configuration of FIG. 22 (b), and an electrode pair 11c including a silver voltage electrode 19a and a copper ground electrode 14 is provided. Yes. In this case, a voltage is first applied by the power source 12c using the copper ground electrode 14 as an anode and the silver voltage electrode 19a as a cathode, and a required amount of copper ions is dissolved in the drain water 8. Then, a voltage is applied by using the silver voltage electrode 19a as an anode and the copper ground electrode 14 as a cathode to dissolve silver ions in drain water. Thereby, the effect similar to the electrode structure shown to Fig.22 (a) can be acquired.

Embodiment 4 FIG.
An air conditioner according to Embodiment 4 of the present invention will be described. In this embodiment, the difference from Embodiment 2 will be mainly described, and the same functions and configurations will be described using the same reference numerals.

  FIG. 23 is a schematic cross-sectional view showing a configuration in the vicinity of the drain pan 7 of the air conditioner according to the present embodiment. The structure of the air conditioner according to the present embodiment is the same as that of the air conditioner of the second embodiment shown in FIG. The present embodiment is different from the second embodiment in that an electrical conductivity detector 16 that detects the electrical conductivity of the drain water 8 is provided. A detection signal from the electrical conductivity detector 16 is output to the controller of the power source 12. In FIG. 23, the electrode group 11a (the voltage electrodes 13 and 19 and the ground electrode 14) having the configuration shown in FIG.

  The electrical conductivity detector 16 will be described. Since the water quality of the drain water 8 is in the range of 10 to several hundred μS / cm, the electrical conductivity detector 16 is configured as an alternating current two-electrode suitable for detecting a relatively low electrical conductivity. That is, the principle is to measure resistance when two electrodes are opposed to each other and AC is applied. As a material of the electrode portion, stainless steel, platinum, carbon graphite, or the like is desirable in order to avoid adhesion of dirt on the electrode.

The operation of the air conditioner according to the present embodiment will be described.
When the cooling operation is started, moisture in the air condenses on the surface of the heat exchanger 6, and the drain water 8 flows out to the drain pan 7. The drain water 8 remains in the drain pan 7 until it reaches the height of the suction port 4 a of the drain pump 4. When the water level rises to the height of the suction port 4a of the drain pump 4 (lower limit water level 17), the drain pump 8 starts discharging the drain water 8, and a certain amount of drain water 8 is continuously discharged. The water level of the drain water 8 at this time is maintained at the lower limit water level 17. When the water level of the drain water 8 is at the lower limit water level 17, the silver ion sterilization effect promoting portion 2 (the voltage electrode 13 and the ground electrode 14 of the electrode group 11a) is immersed in the drain water 8. When the cooling operation is stopped and the drain pump 4 is stopped, the water level of the drain water 8 on the drain pan 7 is increased by the amount of the return water. The water level at that time is the upper limit water level 18. The water level at that time is detected by the water level sensor 5, and a necessary amount of copper ions is generated from the silver ion sterilization effect promoting portion 2 (the voltage electrode 13 of the electrode group 11a).

  On the other hand, the silver ion generator 1 (the voltage electrode 19 of the electrode group 11a) is immersed in the drain water 8 when the water level rises due to the return water. In the drain water 8 from which the copper ions are eluted, the silver ions are rapidly eluted from the silver ion generating part 1 (voltage electrode 19). At that time, the electrical conductivity of the drain water 8 is detected by the electrical conductivity detector 16. The voltage electrode 19 of the electrode group 11a generates silver ions so as to have an appropriate silver ion concentration (see FIG. 5) according to the electric conductivity by voltage application from the power source 12. As a result, by elution of silver ions in the presence of copper ions and sterilization in the presence of silver ions and copper ions, a high sterilization effect on the microorganisms of the drain water 8 can be obtained regardless of the electrical conductivity of the drain water 8. .

  According to such a configuration, silver ions can be eluted from the electrode group 11a only when the amount of silver ions eluted from the silver ion generator 1 is small and the electrical conductivity is difficult to obtain a bactericidal effect. Therefore, after suppressing the generation amount of silver ions as much as possible, the sterilizing effect of the drain water 8 can be maintained high, and the life of each electrode can be extended.

  Further, by controlling the power source 12 and the electrode group 11a (the voltage electrode 13 and the ground electrode 14) according to the electric conductivity detected by the electric conductivity detector 16, the copper ion of the drain water 8 is adjusted to an appropriate concentration. Also good.

Other embodiments.
The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, a ceiling cassette type four-way air conditioner is given as an example. However, the present invention can also be applied to a ceiling cassette type one-way or two-way air conditioner. It can also be applied to other air conditioners such as a ceiling-embedded type, a ceiling-suspended type, a wall-mounted type, and a floor-mounted type other than the ceiling cassette type.

  In addition, the above embodiments and modifications can be implemented in combination with each other.

  1 Silver ion generation part, 2 Silver ion sterilization effect promotion part, 2a Copper plate, 3 Drain pan sterilization mechanism, 4 Drain pump, 4a Suction port, 5 Water level sensor, 6 Heat exchanger, 7 Drain pan, 7a Bottom face, 8 Drain water, 9 , 11, 11b, 11c Electrode pair, 10, 12, 12a, 12b, 12c Power supply, 11a Electrode group, 13, 19, 19a Voltage electrode, 14, 20 Ground electrode, 15 Drain water flow path, 16 Electrical conductivity detector, 17 lower limit water level, 18 upper limit water level, 21 body casing, 22 electric blower, 24 air passage, 26 decorative panel, 27 air suction port, 28 suction grille, 29 air outlet, 29a wind direction plate.

Claims (10)

An air conditioner including a drain pan that receives drain water generated by a heat exchanger,
A silver ion generator for eluting silver ions into the drain water;
An air conditioner comprising: a silver ion sterilization effect promoting unit for eluting at least one type of metal ion other than silver ions into the drain water.   The air conditioner according to claim 1, wherein the metal ions are copper, zinc, or nickel ions.   The air conditioner according to claim 1 or 2, wherein the concentration of the metal ions in the drain water is a concentration that does not exceed the concentration of the silver ions in the drain water.   The air conditioner according to any one of claims 1 to 3, wherein the silver ion generation unit includes an inorganic antibacterial agent containing silver or a metal member containing silver. A drain pump for discharging the drain water;
The air conditioner according to any one of claims 1 to 4, wherein the silver ion generation unit is installed above a height of a suction port of the drain pump.   The air conditioner according to claim 5, wherein at least a part of the silver ion sterilization effect promoting portion is installed at the same level as or lower than the height.   The silver ion sterilization effect promoting unit includes a voltage electrode containing at least one metal other than silver, a ground electrode, and a power source that applies a voltage according to the level of the drain water between these electrodes. The air conditioner according to any one of claims 1 to 6, wherein the air conditioner is provided.   The said silver ion generation part is equipped with the voltage electrode containing silver, the ground electrode, and the power supply which applies a voltage according to the water level of the said drain water between these electrodes. The air conditioner as described in any one of Claims 7-7.   The air conditioner according to claim 8, wherein a power source of the silver ion generator applies a voltage between the electrodes in accordance with an electric conductivity of the drain water.   The air conditioner according to any one of claims 1 to 9, wherein the silver ion generation unit and the silver ion sterilization effect promotion unit are disposed apart from each other without contacting each other. .

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