JP2009285543A - Neutralizing method for drain water, and condensing hot water supply device performing the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condensing hot water supply device where, even iwhen drain water is temporarily stored and exhausted, a neutralization treatment can be performed in a state that the propagation and multiplication of microorganisms are securely intercepted without requiring sterilization treatment equipment. <P>SOLUTION: The drain water with strong acidity generated in a secondary heat exchanger 1 is stored as it is in a drain water tank 4 and is stored in an alkali-treated water tank 5 while being passed through an alkali treatment tank 50 and converted into alkali-treated water by the switching of a switching valve 6, and the storages are performed in a bacteriostasis environment in both the cases. The switching of the switching valve is controlled by water level electrodes 41 to 44, 51 to 54, and the storage amount ratio between the drain water and the alkali-treated water is retained within a prescribed range. When it reaches a prescribed water exhausting timing or it is filled, a water exhaust valve 7 is opened, the drain water and alkali-treated water are joined and mixed, and the mixed water is neutralized and is then exhausted from a water exhaust port 20 through a bathtub 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for neutralizing drain water, which is condensate of combustion exhaust gas, and a condensing hot water supply apparatus for carrying out the method, and in particular, drains after storing a predetermined amount, or a predetermined drain timing arrives. It relates to the technology for draining after storing until it is done.

  In general, a condensing hot water supply device is also called a so-called latent heat recovery type hot water supply device or a high-efficiency hot water supply device. When heating the incoming water by sensible heat of combustion heat to supply hot water, the combustion exhaust gas after heating the incoming water It is a hot water supply device that aims to increase the efficiency of heat utilization by further recovering the latent heat of the. Here, condensing means condensing, and it is named as a condensing hot water supply device because high efficiency is achieved by condensing water vapor contained in combustion exhaust gas to obtain condensation heat (latent heat). Yes.

  In such a condensing hot water supply apparatus, when the exhaust gas after passing through the heat exchanger for sensible heat recovery is introduced into the heat exchanger for latent heat recovery to recover the latent heat, the combustion exhaust gas is recovered as latent heat. When contacted with the heat exchanger for use, water vapor in the combustion exhaust gas is condensed to generate strongly acidic drain water (condensed water). Since this drain water contains nitrogen oxides (NOx) and sulfur oxides (SOx) taken from combustion exhaust gas and is strongly acidic, it is necessary to at least neutralize it to drain it to the outside. Usually, the neutralization is performed by collecting drain water and bringing it into contact with a neutralizing agent such as calcium carbonate.

  As a method of neutralization treatment, neutralize the drainage after neutralizing this strongly acidic drain and draining water generated by cooling the exhaust gas from the engine of the engine driven heat pump with the outside air. There is known one that is neutralized by supplying and mixing a neutralizing liquid from a neutralizing liquid tank to drain water supplied to a treatment tank (for example, see Patent Document 1 or 2). In this case, the neutralization liquid supply on / off valve and the drain water discharge on / off valve are interlocked with each other in accordance with the level of the drain water in the neutralization treatment tank or the rise of the water level. It has been proposed that the drain water is neutralized regardless of the amount of drain water generated by allowing the drain water discharge on-off valve to open at the same time.

JP-A-62-294492 Japanese Patent Laid-Open No. 62-294493

  However, if the drain water is neutralized and stored before draining it to a drain tank, etc., the drain water before neutralization is strongly acidic, so microorganisms cannot propagate and multiply. However, it is conceivable that the drain water after the neutralization treatment may fall into a state where microorganisms can grow and grow. The propagation and proliferation of such microorganisms may cause the formation of biofilm such as slime in the drainage channel and the generation of malodor when the microorganisms propagate and propagate for a long time.

  For the occurrence of such an inconvenience, special measures are required when bath piping or bath drainage equipment is used as a drain water drainage path from the condensing hot water supply device. For this reason, when draining water after storing the drain water after neutralization treatment in a drain tank or the like, it may be possible to perform sterilization treatment to prevent or suppress the growth and proliferation of microorganisms, In this case, it is necessary to add equipment for sterilization treatment, a sterilizing agent, and the like, which is against the demand for cost reduction and compactness.

  On the other hand, it is conceivable that the drain water after the neutralization treatment is allowed to flow, for example, directly into a miscellaneous drain pipe or drainage basin without being stored, but in this case, from the tip of a hose or the like extending from the condensing hot water supply device. For example, drainage water after neutralization will come out every time the combustion operation is performed. In this regard, when installing a new condensing water heater at the site of a newly built apartment house, a detached house or an existing detached house, a dedicated pipe for drain water drainage can be installed easily. Although there will be no hindrance, especially when installing a condensing hot water supply device on an existing apartment building, it is difficult to construct a dedicated pipe for drain water drainage on the pipe shaft of the apartment, for example. Therefore, measures are necessary. For example, if drain water that slightly comes out flows into the corridor or the like of the apartment house, the corridor or the like gets wet every time the combustion operation is performed.

  For this reason, about the drain water in a condensing hot water supply apparatus, the countermeasure by the system which drains after temporarily storing is requested | required, and the utilization of the drainage facilities of a bathtub or a bathroom is also considered for the drainage destination. However, if a method of neutralizing the drainage water by passing it through a neutralizing tank filled with a neutralizing agent such as calcium carbonate after draining is used after draining, the growth of microorganisms in the neutralizing tank・ Inconvenience may occur that there is a possibility that a situation where proliferation is possible will occur.

  The present invention has been made in view of such circumstances. The purpose of the present invention is to provide equipment for sterilization, a sterilizing agent, etc., even when draining water after temporarily storing drain water. A drain water neutralization treatment method and a condensing hot water supply device for realizing this method that can neutralize treatment and drainage in a state in which the growth and growth of microorganisms are reliably prevented without requiring water. There is to do.

  In order to achieve the above object, in the invention relating to the drain water neutralization treatment method, the generated drain water is first and 2 is stored in each of the two tanks, and the drain water is stored in the first tank as it is, while the second tank is subjected to an alkali conversion treatment so that the drain water becomes reverse alkaline. Store. And at the time of the drainage after storage, it was decided to drain the neutralized water as it is at the same time as the drain water from the first tank and the alkali treated water from the second tank are merged and mixed. Claim 1).

  In the case of this drain water neutralization treatment method, drain water that is in an acidic state is stored in the first tank, and alkaline alkaline treatment water is stored in the second tank. The storage can be maintained in a bacteriostatic environment to prevent the growth and proliferation of microorganisms. And, when draining, drain water and alkali treated water are mixed and mixed to mix and neutralize and drain simultaneously with this neutralization treatment, eliminating the opportunity for microbial propagation and growth. . As a result, even when draining after temporarily storing, neutralization treatment and drainage can be performed in a state that reliably prevents the growth and growth of microorganisms without the need for sterilization equipment or disinfectant. Will be able to.

  In the invention relating to the condensing hot water supply apparatus for carrying out such a neutralization method, a sensible heat recovery heat exchanger that recovers sensible heat from the combustion gas generated by the combustion of the burner, and the sensible heat recovery heat The following specific items were provided for a condensing hot water supply apparatus including a latent heat recovery heat exchanger that recovers latent heat from combustion exhaust gas after passing through the exchanger. That is, the first tank that receives the drain water generated in the latent heat recovery heat exchanger and stores it as it is, and the second tank that receives the drain water and stores the alkali treated water by alkali conversion treatment. A tank, flow path switching means for switching supply of drain water derived from the latent heat recovery heat exchanger to the first tank or the second tank, drain water stored in the first tank, and the second tank A drainage means for draining the stored alkali-treated water so as to be openable and closable is provided. Then, as the drainage means, the first tank side and the second tank side are communicated with each other by the opening operation, and the drain water from the first tank and the alkali treated water from the second tank are joined together and mixed. By making it neutralize both, it was set as the structure drained to the downstream side simultaneously (Claim 2).

  In the case of this condensing hot water supply device, the drain water from the latent heat recovery heat exchanger is supplied to the first tank or the second tank by switching the flow path by the flow path switching means. It can be switched and stored in both tanks. At this time, in the second tank, the supplied drain water is subjected to alkali conversion treatment and stored in the state of alkali treated water. During drainage, the drainage means in the first tank and the alkali treated water in the second tank are neutralized by being merged and mixed together by opening the drainage means. It becomes possible to drain the water. As a result, even if the action is based on the above neutralization treatment method, that is, when the water is temporarily stored and then drained, it does not require sterilization equipment or a sterilizing agent, so that microorganisms can be propagated and propagated. In the condensing hot water supply apparatus, it is possible to obtain the effect that the neutralization treatment and the drainage can be performed in a surely blocked state.

  In this condensing hot water supply device, the water level detection means for detecting the stored water levels in the first tank and the second tank, respectively, and the flow path switching of the flow path switching means is controlled based on the water level detection by the water level detection means. And a control means for performing the control (claim 3). By doing so, the flow path switching of the flow path switching means is controlled so that the storage volume ratio, which is the ratio between the storage volume of the first tank and the storage volume of the second tank, is maintained within a predetermined range. The storage ratio is always maintained within the specified range, so that the drainage at the same time as the neutralization process by opening the drainage valve can be performed no matter what stage the drainage timing arrives. The mixing ratio of the drain water and the alkali treated water is maintained at a value corresponding to the above-mentioned storage amount ratio, so that the neutralization treatment can be performed reliably.

  Further, the control means may be configured to execute control for opening the drainage means based on the water level detection by the water level detection means and / or the apparatus operating state (Claim 4). By doing in this way, for example, it becomes possible to execute automatic drainage at the timing when both tanks reach a predetermined water level or when the operation state of the apparatus is suitable for drainage.

  Further, in the invention relating to another condensing hot water supply apparatus for carrying out the neutralization method, a sensible heat recovery heat exchanger for recovering sensible heat from combustion gas generated by combustion of a burner, and the sensible heat recovery The following specific items are provided for a condensing hot water supply apparatus including a latent heat recovery heat exchanger that recovers latent heat from the flue gas after passing through the heat exchanger. That is, the first tank that receives the drain water generated in the latent heat recovery heat exchanger and stores it as it is, and the second tank that receives the drain water and stores the alkali treated water by alkali conversion treatment. A tank, a conduit for guiding drain water derived from the latent heat recovery heat exchanger to either the first tank or the second tank, drain water stored in the first tank, and second A drainage means for draining the alkali-treated water stored in the tank so as to be openable and closable is provided. When the amount of storage in the one tank reaches a predetermined stored water level, a communication path for introducing drain water exceeding the stored water level to the other tank by overflow is connected to the water conduit. As the drainage means, the first tank side and the second tank side are communicated with each other by the opening operation, and the drain water from the first tank and the alkali treated water from the second tank are joined together and mixed. By making it neutralize both, it was set as the structure drained to the downstream side simultaneously (Claim 5).

  In the case of this condensing hot water supply device, drain water is introduced into one of the first tank and the second tank through the water conduit, and if the tank reaches a predetermined stored water level, the communication path is connected to the other tank. The drain water is introduced through the overflow through the water. Therefore, unlike the condensing hot water supply apparatus according to claim 2, it is possible to easily store in both tanks without requiring a flow path switching means. At that time, the drain water introduced in the second tank is subjected to alkali conversion treatment and stored in the state of alkali treated water. And, at the time of drainage, the drain water in the first tank and the alkali treated water in the second tank are joined together and mixed by the opening operation of the drainage means, as in the condensing hot water supply apparatus according to claim 2. It becomes neutralized by this, and it becomes possible to drain to the downstream side simultaneously with this neutralization process. As a result, even if the action is based on the above neutralization treatment method, that is, when the water is temporarily stored and then drained, it does not require sterilization equipment or a sterilizing agent, so that microorganisms can be propagated and propagated. In this condensing hot water supply apparatus, it is possible to obtain the effect that the neutralization treatment and the drainage can be performed in a surely blocked state.

  In each of the above-described condensing hot water supply devices, a mixing and stirring unit that mixes and stirs the drain water and the alkali-treated water combined in the draining unit can be interposed in the flow path at the downstream side of the draining unit ( Claim 6). By doing in this way, mixing and stirring of drain water and alkali-treated water is further promoted, and the neutralization process is more reliably performed.

  Further, as the second tank in each of the above-mentioned condensing hot water supply devices, an alkali treatment tank is provided which is disposed at the drain water inlet side position and converts the drain water into alkali treated water by alkali conversion treatment. The alkali treatment tank may have a configuration in which an alkali conversion agent is filled therein and drain water is converted into alkali treatment water having predetermined alkalinity by contact with the alkali conversion agent (Claim 7). By doing in this way, it becomes possible to convert drain water into alkaline treatment water reliably, and to be able to reliably store predetermined alkaline treatment water in the second tank.

  As described above, according to the method for neutralizing drain water according to claim 1, both the inside of the first tank is drained in an acidic state and the inside of the second tank is alkaline alkaline treated water. Both can be maintained in a bacteriostatic environment storage state, thereby preventing the growth and proliferation of microorganisms. And after draining and mixing with drain water and alkali treated water at the time of drainage and mixing, and draining at the same time as this neutralization treatment, it is possible to eliminate the opportunity for the growth and growth of microorganisms become able to. As described above, even when draining after temporary storage, neutralization treatment and drainage should be performed in a state that reliably prevents the growth and growth of microorganisms without the need for sterilization equipment or disinfectant. Will be able to do.

  According to the condensing hot water supply device of any one of claims 2 to 4 and claims 6 and 7, the supply destination of the drain water from the latent heat recovery heat exchanger is switched by the channel switching by the channel switching means. The drain water in the first tank and the alkali treated water in the second tank are merged and mixed with each other by opening the drainage means when draining, and can be stored in both the first and second tanks. It can neutralize by this, and it becomes possible to drain to the downstream side simultaneously with this neutralization process. As a result, the effects of the above drain water neutralization treatment method, that is, even when draining after temporarily storing, the propagation of microorganisms without the need for sterilization equipment or disinfectant, etc. -A condensing hot water supply apparatus can obtain the effect that neutralization treatment and drainage can be performed in a state where growth is reliably prevented.

  In particular, according to the third aspect of the invention, the flow path switching of the flow path switching means is controlled so as to maintain the storage volume ratio, which is the ratio between the storage volume of the first tank and the storage volume of the second tank, within a predetermined range. By maintaining the storage volume ratio within the specified range, drainage is performed at the same time as neutralization by opening the drain valve, regardless of the stage of drainage. If it does so, the mixing ratio of drain water and alkaline treatment water will be maintained to the thing corresponding to the said storage amount ratio, and a reliable neutralization process can be performed now.

  According to the fourth aspect, for example, automatic drainage control can be realized at the timing when both tanks reach a predetermined water level or when the operation state of the apparatus is suitable for drainage.

  According to the condensing hot water supply device of any one of claims 5 to 7, drain water is introduced into one of the first tank and the second tank through the water conduit, and the tank If the reservoir water level is reached, drain water can be introduced to the other tank by overflow through the communication passage, and without the need for a flow path switching means as in the condensing hot water supply apparatus of claim 2, It can be stored in both tanks. And also at the time of drainage, like the condensing hot water supply apparatus of claim 2, the drain water in the first tank and the alkali treated water in the second tank are merged and mixed together by the opening operation of the drainage means. The water can be neutralized by this, and can be drained to the downstream side simultaneously with this neutralization treatment. As a result, even if the effect based on the neutralization treatment method described above, that is, when draining after temporary storage, it is possible to propagate and multiply microorganisms without the need for sterilization equipment or disinfectant. This condensing hot water supply apparatus can also obtain the effect that neutralization treatment and drainage can be performed in a reliably blocked state.

  In particular, according to the sixth aspect, the mixing and stirring of the drain water and the alkali-treated water can be further promoted by the mixing and stirring means, and the neutralization process can be more reliably performed.

  According to the seventh aspect, the drain water can be reliably converted into the alkaline treated water, and the predetermined alkaline treated water can be reliably stored in the second tank.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows a main part of a condensing hot water supply apparatus E according to an embodiment of the present invention, wherein 1 is a secondary heat exchanger as a heat exchanger for recovering latent heat, 2 is a bathtub, 3 is a recuperation of bath water. A recirculation circuit for carrying out, 4 is a drain water tank as a first tank for storing strongly acidic drain water derived from the secondary heat exchanger 1 as it is, and 5 is a strong acid derived from the secondary heat exchanger 1 An alkali-treated water tank as a second tank for storing the drain water after converting the drain water into a predetermined alkalinity, 6 is the first tank 4 or the second tank for the strongly acidic drain water derived from the secondary heat exchanger 1. 5 is a switching valve as a flow path switching means for switching supply to either one of the five tanks, by switching both the first tank 4 side and the second tank 5 side simultaneously on the downstream side to open and close the first tank 4 side. Acidic drain water and alkaline treatment in the second tank And water is combined with each other is a drain valve for draining downstream.

  In the present embodiment, after the neutralization process is performed by merging and mixing the strongly acidic drain water in the drain water tank 4 and the alkali treated water in the alkali treated water tank 5 by the drain valve 7, The neutralized drain water is allowed to flow into the recirculation circuit 3 to be discharged into the bathtub 2 through the external piping 30 outside the recirculation machine. The neutralized drain water discharged into the bathtub 2 is drained from the drain port 20 to the general drainage facility 22 via the bathtub pan 21. Condensing is performed by the recirculation circuit 3 installed in the machine of the condensing hot water supply apparatus E and the external piping 30 connected to the recirculation circuit 3 at the connection portions 300a and 300b and installed outside the apparatus. A recirculation circuit that circulates the bath water for reheating between the hot water supply device E and the bathtub 2 is configured.

  The secondary heat exchanger 1 includes a heat exchanger case 11 and a heat exchanger main body 12 such as a multi-tube type disposed in the heat exchanger case 11. The flue gas supplied through the flue gas passage 10 to the secondary heat exchanger 1 flows into the inside from the inlet 111 at one side position (left side position in the figure) of the heat exchanger case 11, and the other side position. After flowing toward the outlet 112 (right side position in the figure), it is discharged from the outlet 112 to the outside of the machine. Then, while the combustion exhaust gas flows from the upstream inlet 111 side to the downstream outlet 112 side, it comes into contact with the outer wall of the heat exchanger body 12 through which cold water enters, and is included in the combustion exhaust gas. The condensed water vapor condenses, and the condensed water droplets (drain water) D are collected along the upper surface of the drain pan (drain receiving portion) 11a constituted by the inner surface of the bottom plate 113 of the heat exchanger case 11, The drain water thus made flows down to the switching valve 6 through the outlet pipe 13.

  The drain pan 11a shown in the figure is formed as an inclined surface having a downward slope from the upstream inlet 111 side toward the downstream outlet 112 side, and the vicinity of the outlet 112 being the lowest position of the inclined surface. The outlet plate 13 is connected to the bottom plate 113 so that the upstream end thereof is open. As a result, drain water that has fallen from the outer surface of the heat exchanger main body 12 to the drain pan 11a is guided to the upstream opening end 131 of the drain water outlet pipe 13 by the gravity action and collected along the inclined surface. ing. Conversely, the drain pan may be formed on an inclined surface having a downward slope from the outlet 112 side toward the inlet 111 side, and the upstream end of the outlet pipe 13 may be opened near the inlet 111 side.

  The drain water tank 4 stores the strongly acidic drain water generated in the secondary heat exchanger 1 as it is, thereby maintaining the environment in which microorganisms cannot be propagated and propagated during the storage period. That is, since the drain water introduced into the drain water tank 4 is strongly acidic (for example, about pH 3), it is not suitable for the growth of most microorganisms, and the internal drain water is strongly acidic regardless of the storage period. Therefore, the growth of the microorganism itself is maintained in an impossible state.

  The drain water tank 4 is provided with a plurality of (four in the illustrated example) water level electrodes 41, 42, 43, and 44 for detecting the water level as means for detecting the level of the internal drain water. These four water level electrodes 41, 42, 43, 44 are stored in both the low water level electrode 41 for detecting a low water level corresponding to an almost empty state, and both the drain water tank 4 and the alkali treated water tank 5. Are constituted by water level electrodes 42, 43, 44 arranged to detect different water levels in order to control so as to maintain a storage amount ratio within a predetermined range. In the example shown in the figure, the storage amount ratio is controlled by three types: a first middle water level electrode 42, a second middle water level electrode 43, and a high water level electrode 44. The first middle water level electrode 42 is set to a position for detecting a water level (medium water level 1) corresponding to, for example, 50% of the full water amount of the drain water tank 4, and the high water level electrode 44 is a high water level corresponding to the vicinity of the full water amount. The second middle water level electrode 43 is set to a position corresponding to the intermediate water level (medium water level 2) of both the middle water level 1 and the high water level. This is because priority is given to continuation of storage without draining even when a later-described drainage timing arrives until the intermediate water level 1 is reached, and after the intermediate water level 1 is reached, the above-described storage amount ratio range is maintained. The position of each of the water level electrodes 42, 43, 44 is set under a policy that drainage is possible any time when the drainage timing arrives with priority given to the above control. Therefore, the number of water level electrodes may be further increased to detect each water level that is further subdivided between the middle water level 1 and the high water level, thereby increasing the control accuracy of the storage amount ratio. The control of the storage amount ratio will be described later in detail.

  The alkali-treated water tank 5 includes an alkali treatment tank 50 on the inflow side thereof, and the drain water from the secondary heat exchanger 1 passes through the alkali treatment tank 50, whereby a predetermined strongly alkaline (for example, about pH 10) alkali. In the state converted into treated water, it flows into the alkaline treated water tank 5 and is stored. That is, the alkali treatment tank 50 is filled with an alkali conversion agent (for example, magnesium oxide), and drain water led out from the secondary heat exchanger 1 passes through the alkali conversion agent packed layer from one end to the other end. While flowing, it comes into contact with an alkali conversion agent and is converted into alkali treated water having alkalinity as described above, which flows into the alkali treated water tank 5. As a result, as in the drain water tank 4, the environment is maintained in which the microorganisms cannot propagate and multiply during the storage period. That is, since the alkali-treated water introduced into the alkali-treated water tank 5 has been converted to have strong alkalinity as described above, it is not suitable for the growth of most microorganisms, and it is not suitable for the inside or outside of the storage period. This alkali-treated water is maintained in a strong alkalinity, so that the microorganism itself cannot be grown. That is, both the drain water tank 4 and the alkali-treated water tank 5 form and maintain a bacteriostatic environment.

  Further, the alkali treated water tank 5 is formed so that the internal horizontal sectional area is set to be the same as that of the drain water tank 4 and the same storage amount is obtained at the same water level. In the alkali treated water tank 5, water level electrodes 51, 52, 53, 54 for detecting the same water level (reserved amount) as the water level electrodes 41, 42, 43, 44 in the drain water tank 4 are arranged. It is installed. That is, four types of low water level electrode 51, first middle water level electrode 52, second middle water level electrode 53, and high water level electrode 54 are provided as the water level detecting means.

  The switching valve 6 is constituted by, for example, a three-way switching valve, and when switched to the drain water tank 4 side, the drain water led out by the outlet pipe 13 is supplied to the drain water tank 4 through the branch pipe 14, and conversely, the alkali treated water tank 5 When switched to the side, the drain water led out by the outlet pipe 13 is supplied to the alkali treatment tank 50 of the alkali treated water tank 5 through the branch pipe 15.

  Further, the drain valve 7 shuts off both the drain water downstream from the drain water tank 4 and the alkali treated water tank 5 in the closed operation state, and both the drain water tank 4 and the alkali treated water tank 5 in the opened operation state. Both are designed to communicate with the downstream side. That is, by opening the drain valve 7, the drain water in the drain water tank 4 led out from the outlet pipe 16 and the alkali treated water in the alkali treated water tank 5 led out from the outlet pipe 17 are supplied to the drain valve 7. After being merged with each other and mixed, the water is drained through the downstream merge pipe 18. Specifically, the drain valve 7 is opened so that the downstream side of the drain water tank 4 (the outlet pipe 16 side) and the downstream side of the alkaline treated water tank 5 (the outlet pipe 17 side) have the same opening amount. At the same time, these are communicated with the side of the merging / extracting pipe 18 which is the downstream side thereof. Thereby, in the drain valve 7 in the open operation state, the drain water in the drain water tank 4 and the alkali treated water in the alkali treated water tank 5 join and mix with each other at the same mixing ratio as a predetermined storage amount ratio as will be described later. Then, the neutralization treatment is performed, and at the same time as this neutralization treatment, the drain water that has been neutralized is drained to the downstream side. That is, the neutralization treatment and the drainage after the neutralization treatment are continuously performed without causing a time lag so that there is no time margin for propagation of microorganisms.

  The drain water tank 4, the alkali treated water tank 5, the switching valve 6, the drain valve 7, and the water level electrodes 41 to 44, 51 to 54 are preferably made of a material having acid resistance or alkali resistance. As the material for the drain water tank 4 and the alkali-treated water tank 5, for example, polypropylene may be used, and as the material for the water level electrodes 41 to 44, 51 to 54, stainless steel or carbon may be used.

  When mixing by the drain valve 7 and mixing, a mixing and stirring means 8 may be further provided to positively mix the drain water and the alkali-treated water. For example, a line mixer may be used as the mixing and stirring unit 8, and the mixing and stirring unit 8 may be interposed, for example, at a position of the drainage valve 7 on the side of the merging / extracting pipe 18, or at an intermediate position of the merging / outleting pipe 18. Thereby, the mixing and stirring of the drain water and the alkali-treated water can be further promoted more than the case of only the mixing promotion by the turbulent flow generation accompanying the confluence at the drain valve 7, and the drain water and the alkali-treated water The neutralization process by mixing can be achieved more reliably.

  The downstream end of the confluence derivation pipe 18 is connected to the recirculation circuit 3 (in the illustrated example, the forward path 3b) via a three-way switching valve 19, and the three-way switching valve 19 and the drain valve 7 are connected to a predetermined path. The drain water, which is opened and operated in synchronization with each other by a controller described later, is discharged to the recirculation circuit 3 and discharged into the bathtub 2 through the recirculation circuit 3 and the external pipe 30. It drains from the mouth 20. Here, the three-way switching valve 19 is normally closed so that the side of the merging / deriving pipe 18 is cut off from the outgoing path 3b and is opened, whereby the side of the merging / leading pipe 18 is communicated with the outgoing path 3b. Become. In addition, the discharge | emission to the bathtub 2 is the case where the condensing hot-water supply apparatus E is installed in the 1st floor and the bathtub is similarly installed in the 1st floor, the level of the drain water tank 4 and the alkali treated water tank 5 and the bathtub 2 For example, when the condensing hot water supply device E is installed on the first floor and the bathtub 2 is installed on the second floor, for example, the above-described confluence derivation pipe 18 may be used. The operation may be performed by operating a pump (not shown) interposed between the two.

  Here, the three-way switching valve 19 is normally maintained in the communication state of the recirculation circulation path 3 (forward path 3b) with the side of the merging / deriving pipe 18 being closed. The downstream end of the merging / deriving pipe 18 may be connected to either one or both of the return path 3a and the forward path 3b constituting the recirculation circuit 3, and this recirculation circuit 3 is formed. One or both of the return path 3a and the outbound path 3b constitute a bath pipe that is connected to the bathtub 2.

  An example of a specific condensing hot water supply apparatus to which the secondary heat exchanger 1, the drain water tank 4 and the alkali treated water tank 5 as shown in FIG. 1 are applied will be briefly described with reference to FIG.

  The condensing hot water supply apparatus illustrated in FIG. 2 is configured as a composite heat source machine type having both the hot water circulation heating function, the bath reheating function, and the bath hot water function in addition to the hot water supply function. This is a latent heat recovery type that improves the efficiency by recovering latent heat from combustion exhaust gas in addition to sensible heat in the combustion heating section. In practicing the present invention, the present invention can be applied to at least a combustion heating unit provided with a secondary heat exchanger 1 for recovering latent heat, and has a bath replenishment function. If the circulation circuit 3 is installed, it is more preferable that drain water can be easily discharged using bath equipment such as bath piping and bathtub 2.

  In the figure, reference numeral 21 is a hot water supply circuit for realizing a hot water supply function, 22 is a heating circuit for realizing a hot water circulation heating function, and 23 is a reheating function for realizing a bath reheating function as a bath side circulation circuit. A circuit 24 is a pouring circuit for realizing a bathing function, and a reference numeral 25 is a drain water treatment circuit for neutralizing drain water generated in the secondary heat exchanger 1 for recovering latent heat, Reference numeral 26 denotes a controller as a control means for controlling the operation of each circuit. In the hot water supply apparatus, the hot water of the heating circuit 22 is heated as the heat source, and the bath water of the hot water circuit 23 is heated by liquid-liquid heat exchange heating with the bath heater 41 to heat up the hot water. Although it is of a type, it is not limited to this, and a reheating is performed with a combustion heating section for reheating (a combustion burner and a heat exchanger heated by the combustion heat of this combustion burner). It may be configured.

  The hot water supply circuit 21 includes a combustion hot burner 31 for hot water supply and a primary heat exchanger 32 for hot water supply for heat exchange heating of the incoming water by the combustion heat of the combustion burner 31 as a combustion heating unit. Is heated mainly in the primary heat exchanger 32 for hot water supply, and the heated hot water is discharged into the hot water outlet 34. At this time, the water entering from the water inlet 33 is passed through the hot water supply heat exchanging portion 1a constituting the secondary heat exchanger 1 before entering the primary heat exchanger 32, In this heat exchanging portion 1a, the water is preheated by the latent heat recovery from the combustion exhaust gas, and then enters the primary heat exchanger 32 and is mainly heated. Then, the hot water heated to a predetermined temperature and discharged into the hot water supply passage 34 is supplied to predetermined hot water supply locations such as a hot water tap 35 and the pouring circuit 24 in a kitchen or bathroom. In the illustrated example, only one hot water tap 35 is shown, but there are usually a plurality of hot water taps 35 disposed in the kitchen, washbasin, bathroom, and the like. The primary heat exchanger 32 and a heating primary heat exchanger 37 described later constitute a sensible heat recovery heat exchanger, and are configured by the hot water supply heat exchanging portion 1a and a heating heat exchanging portion 1b described later. The secondary heat exchanger 1 constitutes a latent heat recovery heat exchanger.

  The heating circuit 22 includes a heating combustion burner 36 and a heating primary heat exchanger 37 that heats and heats the circulating hot water using the combustion heat of the combustion burner 36 as a combustion heating unit, and this heating primary heat exchanger A heating hot water circulation path 38 is passed through 37.

  The hot water circulation path 38 sends low temperature water returned to the expansion tank 39 and stored to the inlet of the heating primary heat exchanger 37 by the operation of the heating circulation pump 40, where it is heated by the combustion burner 36. Hot water is supplied as a heat source to the bath heater 41, which is a liquid-liquid heat exchanger, from the high temperature outgoing path 38a, or supplied to the high temperature heating terminal 43 such as a bathroom dryer via the high temperature outgoing header 42. It has become. Further, by the operation of the circulation pump 40, the low-temperature water in the expansion tank 39 is supplied to the low-temperature heating terminal 45 such as a floor heater via the low-temperature forward header 44, and heat is radiated from all the heating terminals 43 and 45. The low-temperature water having a low temperature is circulated such that the low-temperature water is returned to the expansion tank 39 after passing through the return header 46 through the heating heat exchanger 1b of the secondary heat exchanger 1 for latent heat recovery. ing. In the heating heat exchanger 1b of the secondary heat exchanger 1 described above, the low temperature water is preheated by the latent heat recovery from the combustion exhaust gas of the heating combustion burner 36, and the preheated low temperature water is returned to the expansion tank 39. It has become.

  In the reheating circuit 23, a bath heater 41 as a liquid-liquid heat exchange type heating unit is interposed in a recirculation circulation path 3 composed of a return path 3a and a forward path 3b. The bath water taken out from 2 through the return pipe 30a and the return path 3a is sent to the bath heater 41, where it is reheated by liquid-liquid heat exchange using high-temperature water on the heating circuit 22 side as a heat source. The heated bath water is sent to the bathtub 2 through the outgoing path 3b and the outgoing pipe 30b.

  The pouring circuit 24 includes a pouring passage 48 in which an upstream end branches from the hot water supply circuit 21 and a downstream end joins the recirculation circuit 3, and a pouring solenoid valve that switches between performing and shutting off pouring by opening / closing switching. 49. The pouring solenoid valve 49 is controlled to be opened and closed by the controller 26, and by pouring, the hot water in the hot water outlet channel 34 is poured into the bathtub 2 through the pouring channel 48 and the recirculation circuit 3 (return channel 3a). A predetermined amount of hot water filling is performed.

  The drain water treatment circuit 25 is a drain generated by the flue gas being cooled and condensed by heat exchange for latent heat recovery in the secondary heat exchanger 1 (hot water heat exchange section 1a and heating heat exchange section 1b). It is a circuit installed for water storage and neutralization. That is, the drain water treatment circuit 25 collects the drain water collected and collected by the drain pan 11a (see FIG. 1) disposed at the lower position of the secondary heat exchanger 1 to the switching valve 6 through the outlet pipe 13. It is supplied and stored in the drain water tank 4 as it is by the switching control described later of the switching valve 6 or stored in the alkali-treated water tank 5 after being subjected to alkali treatment until it reaches a predetermined drainage timing. It has become. In addition, the neutralization treatment and the drainage are simultaneously performed by the opening operation control of the drainage valve 7 and the three-way switching valve 19 or the like when the predetermined drainage timing arrives, and the drainage water that has been neutralized is replenished and the circulation path 3 (see FIG. In FIG. 2, the return path 3 a is flowed into the exemplification) to flow into the bathtub 2 and drain from the drain port 20.

  As said drainage timing, what is necessary is just to set the timing when the bathtub 2 is not used, ie, the timing when the hot water filling for bathing is not performed. Assuming the amount of drain water generated in one day, for example, depending on the scale such as the hot water supply capacity of the condensing hot water supply device E and the usage environment, the amount of drain water and the amount stored in both the drain water tank 4 and the alkali treated water tank 5 In view of this, the timing of drainage and the number of times of drainage per day may be set. As the drainage timing, for example, when the drainage timing is set to three times a day, it is set by selecting the timing when the automatic cleaning of the bathtub 2 or the control related to the automatic hot water filling and the automatic warming is not performed. do it. Alternatively, in order to add the timing setting according to the time, it is only necessary to select and set a time zone in which bathing is not normally performed such as 10 am, 4 pm, or 2 am. In addition to these timing settings, the timing at which the storage amounts of the drain water tank 4 and the alkaline treated water tank 5 both become full is set as the drainage timing.

  Next, switching control of the switching valve 6 by the controller 26 will be described with reference to FIGS. 3 and 4.

  In order to start a new storage from the state in which the drain water tank 4 and the alkali treated water tank 5 are both emptied by the previous drainage, first, the drain valve 7 is closed and maintained in the closed state. As indicated by the solid arrow in FIG. 5 (a), the switching valve 6 is opened and switched to the drain water tank 4 side (the outlet pipe 13 and the branch pipe 14 are switched in communication), and the drain from the secondary heat exchanger 1 is switched. Water is supplied to the drain water tank 4 and stored (step S1). This is continued until the stored water level in the drain water tank 4 reaches the middle water level 1, that is, until the first middle water level electrode 42 detects the middle water level 1 (NO in step S2).

  When the first middle water level electrode 42 of the drain water tank 4 detects the middle water level 1 (YES in step S2), the switching valve 6 is placed on the side of the alkali treated water tank 5 as shown by the dashed line arrow in FIG. Then, the drain water from the secondary heat exchanger 1 is supplied to the alkaline treated water tank 5 and stored (step S3). This is continued until the stored water level in the alkali treated water tank 5 reaches the middle water level 1, that is, until the first middle water level electrode 52 detects the middle water level 1 (NO in step S4).

  When the first intermediate water level electrode 52 of the alkali-treated water tank 5 detects the intermediate water level 1 (YES in step S4), the switching valve 6 is moved to the drain water tank 4 side as shown by the solid line arrow in FIG. Switching to open, the drain water from the secondary heat exchanger 1 is supplied to the drain water tank 4 and further stored (step S5). This is continued until the stored water level in the drain water tank 4 reaches the middle water level 2, that is, until the second middle water level electrode 43 detects the middle water level 2 (NO in step S6). If both the storage of drain water up to the middle water level 1 in the drain water tank 4 and the storage of alkali treated water up to the middle water level 1 in the alkali treated water tank 5 are completed (YES in step S4), the drain water thereafter. Switching control (after step S5) for controlling the storage amount ratio of the drain water in the tank 4 and the alkaline treated water in the alkaline treated water tank 5 to a predetermined range is entered.

  When the second middle water level electrode 43 of the drain water tank 4 detects the middle water level 2 (YES in step S6), the switching valve 6 is moved to the alkali treated water tank 5 side as indicated by the solid line arrow in FIG. Switching to open, the drain water from the secondary heat exchanger 1 is supplied to the alkaline treated water tank 5 and stored (step S7). This is continued until the stored water level in the alkali-treated water tank 5 reaches the middle water level 2, that is, until the second middle water level electrode 53 detects the middle water level 2 (NO in step S8).

  When the second intermediate water level electrode 53 of the alkali-treated water tank 5 detects the intermediate water level 2 (YES in step S8), the switching valve 6 is connected to the drain water tank 4 side as shown by the dashed line arrow in FIG. The drain water from the secondary heat exchanger 1 is supplied to the drain water tank 4 and further stored (step S9). This is continued until the stored water level in the drain water tank 4 reaches the high water level, that is, until the high water level electrode 44 detects the high water level (NO in step S10).

  When the high water level electrode 44 of the drain water tank 4 detects a high water level (YES in step S10), the switching valve 6 is opened and switched to the alkaline treated water tank 5 side as shown by the solid line arrow in FIG. Then, the drain water from the secondary heat exchanger 1 is supplied to the alkaline treated water tank 5 and stored (step S11). This is continued until the stored water level in the alkali treated water tank 5 reaches the high water level, that is, until the high water level electrode 54 detects the high water level (NO in step S12).

  6B, when the high water level electrode 54 of the alkali treated water tank 5 detects a high water level (YES in step S12), the drain water and the alkali treated water tank in the drain water tank 4 are detected. Since both of the alkali treated water in 5 have reached a high water level, the drain valve 7 is opened and drained from both the drain water tank 4 and the alkali treated water tank 5 simultaneously (step S13). In the case of this full drainage timing, since both tanks 4 and 5 have the same storage amount, drain water and alkali-treated water have the same 50:50 storage ratio as the drain valve 7 is opened. : Neutralization treatment is performed at a mixing ratio of 50.

  When the water level of each of the tanks 4 and 5 is lowered to a low water level that is almost empty due to drainage, the drain valve 7 is closed. This closing operation is executed when either of the low water level electrodes 41 and 51 of both tanks 4 and 5 does not detect the low water level (YES in step S14; FIG. 4 illustrates the low water level electrode on the alkaline treated water tank side). ). And it returns to step S1 again and continues storage.

  In the switching control after the above step S5, the storage amount ratio between the storage amount of the drain water in the drain water tank 4 and the storage amount of the alkali treated water in the alkali treated water tank 5 is, for example, 56:44 to 31:69. Storage switching control is performed so that the range, that is, drain water: alkali treated water falls within the range of {56 to 31%}: {44 to 69%}. This storage ratio is such that the alkali-treated water after alkali treatment has a pH of about 10 using magnesium oxide as an alkali conversion agent, and the drain water that has been neutralized by mixing with drain water of about pH 3 has a pH of 5.8-8. This assumes a neutrality of about .6. Therefore, when a material other than magnesium oxide is used as the alkali conversion agent, the storage amount ratio also varies accordingly.

  In the switching control of the switching valve 6 described above, in all of the following storage periods after the drain water tank 4 and the alkali-treated water tank 5 have both been stored up to the intermediate water level 1, the storage amount ratio of each storage period The fluctuation is set to be within the above-described storage amount ratio range. That is, while the drain water tank 4 fluctuates from the middle water level 1 to the middle water level 2, the alkali treated water tank 5 maintains the middle water level 1 during that time (from step S5 to step S6 until YES) 5 (b)), while the drain water tank 4 maintains the middle water level 2, while the alkali treated water tank 5 will fluctuate from the middle water level 1 to the middle water level 2 (YES in step S7 to step S8) Until the drain water tank 4 fluctuates from the middle water level 2 to the high water level, while the alkali treated water tank 5 maintains the middle water level 2 (in steps S9 to S10). Until YES, see FIG. 6 (b)), and while the drain water tank 4 maintains a high water level, the alkali treated water tank 5 changes from a middle water level 2 to a high water level (step S1). In to S12 until YES, variation in storage amount ratio as described above in each dotted reference) in FIG. 6 (b) are such that the above storage amount ratio range.

  In the switching control period after step S5, the illustration is omitted, but since the storage amount ratio is controlled within a predetermined range as described above, the predetermined drainage timing set in the controller 26 is If it arrives, it jumps to step S13 at that time, and drains simultaneously with neutralization processing are performed. In this case as well, the water can be drained after a predetermined neutral state.

  According to the above embodiment, in the drain water storage period, the drain water tank 4 and the alkali treated water tank 5 can be maintained in a bacteriostatic environment over the entire period. It is possible to avoid the occurrence of microbial propagation caused by the storage of drain water, and to reliably prevent the occurrence of a situation where microorganisms propagate and multiply. Therefore, it is possible to omit the need to install sterilization equipment such as a sterilization tank regardless of the length of the storage period. In addition, the neutralization process can be reliably performed simultaneously with the drainage. In addition, since the drain water tank 4 and the alkali treated water tank 5 which are main components both store the drain water generated in the secondary heat exchanger 1, a conventional neutralization tank and a storage tank are provided. Compared with the neutralization processing apparatus which prepares and performs the neutralization processing by batch processing, it is possible to achieve a significant compactness in obtaining an equivalent storage amount.

  In the above embodiment, the water level electrodes 41 to 44 and 51 to 54 are provided in order to control the storage amount ratio between the drain water tank 4 and the alkali treated water tank 5 to a predetermined range. Detection means may be used, and the water level detection means may be omitted, and the calculation process performed by the controller 26 may be used instead. For example, the controller 26 estimates the amount of drain water generated in the secondary heat exchanger 1 based on the amount of combustion in the combustion operation of the condensing hot water supply apparatus, the combustion continuation time, and the like, and calculates the switching valve 6 based on this calculated value. It is also possible to control the storage amount ratio between the drain water tank 4 and the alkali treated water tank 5 within a predetermined range by performing the switching control.

Second Embodiment
FIG. 7 shows a main part of a condensing hot water supply apparatus according to the second embodiment of the present invention, in which reference numeral 4a is a drain water tank, and 5a is an alkali treated water tank. In the second embodiment, the switching control of the switching valve 6 and the opening / closing operation control of the drain valve 7 in the first embodiment are unnecessary and simplified. In addition, the same code | symbol as 1st Embodiment is attached | subjected to the same component as 1st Embodiment, and the detailed description which overlapped is abbreviate | omitted.

  Unlike the drain water tank 4 of the first embodiment, the drain water tank 4a is configured as a simple acid-resistant tank that does not include a water level detection means, and opens and closes the drain valve 7 in conjunction with the internal water level instead of the water level detection means. A water level interlocking mechanism 45 to be operated is provided. As this water level interlocking mechanism 45, for example, a pair of float switches or float operating mechanisms may be used. In the illustrated example, the high water level float switch 45a that is turned on when the predetermined high water level is reached to open the drain valve 7 is turned off, and the drain valve 7 is closed when the predetermined low water level corresponding to an empty state is reached. A structure in which the water level interlocking mechanism 45 is configured in combination with the low water level float switch 45b to return to the state is shown. The three-way switching valve 19 on the side of the recirculation circuit 3 is opened and closed simultaneously with the drain valve 7 by the above ON / OFF.

  The alkali-treated water tank 5 a has one end at the inlet of the tank main body 55 that is the original storage part, the water conduit 57 that is partitioned by the partition wall 56 and extends in the vertical direction, and the tank main body 55 that opens at the bottom of the water conduit 57. Is provided with an alkali treatment tank 50a. A downstream end of the outlet pipe 13 for leading drain water from the secondary heat exchanger 1 is connected to the top portion of the water conduit 57, and the drain water introduced into the water conduit 57 passes from the bottom to one end of the alkali treatment tank 50a. Inflow. And while drain water that has flowed into one end of the alkali treatment tank 50a passes to the other end, it is converted into alkali treated water similar to the first embodiment in contact with the alkali conversion agent filled layer filled inside, The converted alkali treated water is stored in the tank body 55. The water conduit 57 is connected to the drain water tank 4a through a communication passage 58 at a predetermined vertical position (refer to the water level indicated by symbol H in FIG. 7), and the stored water level in the alkali treated water tank 5a reaches the water level H. If it rises and reaches the vertical position of the communication path 58, the drain water introduced from the outlet pipe 13 thereafter flows into the drain water tank 4 a through the communication path 58. If the stored water level in the drain water tank 4a reaches the water level H, the stored amount of drain water in the drain water tank 4a and the stored amount of alkaline treated water in the alkaline treated water tank 5a are the same. Each internal volume is set.

  As described above, in the case of the second embodiment, the drain water led out from the secondary heat exchanger 1 through the lead-out pipe 13 enters the water conduit 57, and is first introduced into the alkali treated water tank 5a through the water conduit 57 to be alkalinized. When it is stored in the treatment tank 50a while being converted into alkali treated water and the amount of the alkali treated water reaches a predetermined water level H, the drain water that overflows from the water conduit 57 then passes through the communication passage 58 in the drain water tank 4a. It will be stored in the untreated state. When the amount of drain water stored in the drain water tank 4a also reaches the water level H, the high water level float switch 45a is turned on and the drain valve 7 is opened. Thereby, the drain water in the drain water tank 4a and the alkali treated water in the alkali treated water tank 5a are merged and mixed with each other to be neutralized, and pass through the open three-way switching valve 19 and the recirculation circulation path 3 as they are. It is discharged to the bathtub 2 and drained from the drain port 20. When the drain water tank 4a and the alkali treated water tank 5a are emptied, the low water level float switch 45b is turned off and the drain valve 7 and the three-way switching valve 19 are returned to the closed state. Thereby, storage with respect to the alkali-treated water tank 5a and the drain water tank 4a is started again. When the three-way switching valve 19 is in the closed state, the side of the merging / deriving pipe 18 is blocked from the outgoing path 3b, and in the opened state, the side of the merging / deriving pipe 18 is communicated with the outgoing path 3b.

  According to the second embodiment, the drainage timing is the point in time when both tanks 4a and 5a reach the predetermined water level H, but a simple configuration without mounting a control part such as switching control based on water level detection. Thus, the same function and effect as those of the first embodiment can be obtained.

  In the second embodiment, the drain water derived from the secondary heat exchanger 1 is first introduced into the alkali-treated water tank 5a, converted to alkali, stored, and stored to the water level H and then from the water level H. Although the configuration is shown in which the drain water overflowing is introduced into the drain water tank 4a as it is and stored, the present invention is not limited to this, and the storage order may be reversed. For example, the drain water derived from the secondary heat exchanger 1 is first introduced into the drain water tank and stored as it is, and the drain water overflowing from above the water level H after being stored up to the water level H is supplied to the alkali treated water tank. It is good also as a structure which makes it introduce | transduce through a communicating path, and stores after introduce | transducing this introduced drain water into alkali. Even in this case, the same effect as the second embodiment can be obtained.

<Other embodiments>
The present invention is not limited to the first or second embodiment, but includes other various embodiments. That is, in each said embodiment, although the drain pan 11a is comprised by the bottom face of the baseplate 113, and the bottom face of the baseplate 113 is made into the inclined surface, it is not restricted to this, The case of the secondary heat exchanger 1 separately from a drain pan. When disposed inside, it is not necessary to incline the bottom plate, and the upper surface of the drain pan disposed on the bottom surface side of the bottom plate may be constituted by an inclined surface.

  In each of the above embodiments, the drain water that has been neutralized is allowed to flow into the recirculation circulation path 3 and discharged into the bathtub 2 through the external piping 30 outside the recirculation circulation machine. Although it is made to drain to the general drainage equipment 22 via the pan 21, it does not restrict to this, It drains directly with respect to the bathtub pan 21 through the said external piping 30 or the piping for draining attached to this external piping 30. You may make it not go through the bathtub 2. Or you may make it drain directly with respect to the general drainage facility of an appropriate place, without going through the bathtub pan 21. FIG.

It is a mimetic diagram showing a 1st embodiment of the present invention. It is a schematic diagram of the concrete condensing hot water supply apparatus with which embodiment of this invention is applied. It is a flowchart of the first half part which shows the switching control for storage of 1st Embodiment. It is a flowchart of the second half part which shows the switching control for storage of 1st Embodiment. FIG. 5A is a partial view of FIG. 1 showing a storage situation in the first storage period, and FIG. 5B is a partial view of FIG. 1 showing a storage situation in the next storage period. 6 (a) is a partial view of FIG. 1 showing a storage situation in the next storage period of FIG. 5 (b), and FIG. 6 (b) is a partial view of FIG. 1 showing a storage situation in the next storage period. It is. It is a figure corresponding to FIG. 1 which shows 2nd Embodiment.

Explanation of symbols

1 Secondary heat exchanger (heat exchanger for latent heat recovery)
1a, 1b Secondary heat exchanger (Latent heat recovery heat exchanger)
4,4a Drain water tank (first tank)
5,5a Alkali treated water tank (second tank)
6 Switching valve (channel switching means)
7 Drain valve (drainage means)
8 Mixing and stirring means 26 Controller (control means)
41 to 44, 51 to 54 Water level electrode (water level detection means)
45 Water level interlocking mechanism 50, 50a Alkali treatment tank 57 Water conveyance path 58 Communication path

Claims (7)

A method for neutralizing acidic drain water generated by condensation of combustion exhaust gas,
The generated drain water is stored in the first and second tanks, respectively,
While storing the drain water as it is in the first tank, the second tank stores the drain water after performing an alkali conversion treatment so that the drain water becomes reverse alkaline,
At the time of drainage after storage, the drain water from the first tank and the alkali treated water from the second tank are neutralized by mixing and mixing, and at the same time, the neutralized treated water is drained as it is.
A method for neutralizing drain water characterized by the above. A sensible heat recovery heat exchanger that recovers sensible heat from the combustion gas generated by combustion of the burner, and a latent heat recovery heat exchanger that recovers latent heat from the combustion exhaust gas after passing through the sensible heat recovery heat exchanger, A condensing hot water supply device comprising:
A first tank that receives the drain water generated in the latent heat recovery heat exchanger and stores it as it is, and a second tank that receives the drain water and stores it as alkali treated water by alkali conversion treatment; , A flow path switching means for switching supply of drain water derived from the latent heat recovery heat exchanger to the first tank or the second tank, drain water stored in the first tank, and stored in the second tank. Drainage means for draining the alkali-treated water so that it can be opened and closed,
The draining means causes the first tank side and the second tank side to communicate with each other by the opening operation, and the drain water from the first tank and the alkali treated water from the second tank are merged and mixed together. The condensing hot water supply device is configured to neutralize both of the water and discharge the water downstream. The condensing hot water supply device according to claim 2,
Water level detection means for detecting the stored water levels in the first tank and the second tank, respectively, and control means for controlling the flow path switching of the flow path switching means based on the water level detection by the water level detection means. , Condensing water heater. The condensing hot water supply device according to claim 3,
The said control means is a condensing hot water supply apparatus comprised so that the control which opens the said drainage means based on the water level detection by the said water level detection means and / or an apparatus operating state may be performed. A sensible heat recovery heat exchanger that recovers sensible heat from the combustion gas generated by combustion of the burner, and a latent heat recovery heat exchanger that recovers latent heat from the combustion exhaust gas after passing through the sensible heat recovery heat exchanger, A condensing hot water supply device comprising:
A first tank that receives the drain water generated in the latent heat recovery heat exchanger and stores it as it is, and a second tank that receives the drain water and stores it as alkali treated water by alkali conversion treatment; , A water conduit for guiding drain water derived from the latent heat recovery heat exchanger to one of the first tank and the second tank, drain water stored in the first tank, and a second tank. A drainage means for draining the stored alkaline treated water so that it can be opened and closed;
If the storage amount in the one tank reaches a predetermined storage water level, a communication path for introducing drain water exceeding the storage water level to the other tank by overflow is connected to the water conduit,
The draining means causes the first tank side and the second tank side to communicate with each other by the opening operation, and the drain water from the first tank and the alkali treated water from the second tank are merged and mixed together. The condensing hot water supply device is configured to neutralize both of the water and discharge the water downstream. It is a condensing hot water supply apparatus in any one of Claims 2-5,
A condensing hot water supply apparatus in which a mixing and stirring means for mixing and stirring the drain water and the alkali-treated water merged in the draining means is interposed in the flow path at the downstream side of the draining means. It is a condensing hot water supply apparatus in any one of Claims 2-6,
The second tank includes an alkali treatment tank that is disposed at a drain water inlet side position and converts the drain water into alkali treated water by alkali conversion treatment, and the alkali treatment tank is filled with an alkali conversion agent. A condensing hot water supply device configured to convert drain water into alkali-treated water having a predetermined alkalinity by contact with an alkali conversion agent.

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