Electrode-type steam humidifier and its operation method

Abstract

The present invention relates to an electrode-based steam humidifier (1), a method for its operation and a computer program product suitable for carrying out said method, comprising a steam vessel (2) having a first water inlet (10) for mineral water and at least two electrodes (6) arranged to be at least partially immersed in water filled above a minimum water level, the electrodes (6) being supplied with a voltage such that at least one of the electrodes (6) has a different electrical potential than the other electrode or electrodes (6) and generates an electric current in the water, the steam vessel (2) comprising a second water inlet (11) for demineralized water and means for evaluating the electrical conductivity of the water held in the steam vessel (2), the flow rate through both water inlets (10, 11) for refilling the steam vessel (2) being controlled by a controller (20) based on the evaluated electrical conductivity in order to obtain or maintain a desired electrical conductivity. A method of operating an electrode-based steam humidifier (1) includes assessing the conductivity of water in a steam container (2) of the electrode-based steam humidifier (1) and adjusting the conductivity of water introduced into the steam container (2) for refilling such that the resulting water mixture in the steam container (2) has a desired conductivity. A computer program product of the invention includes program portions designed to carry out the invention when loaded into a digital controller connected to at least the necessary sensors and actuators of the electrode-based steam humidifier (1).

Description

Technical Field

[0001] This invention relates to an electrode type steam humidifier, an operation method thereof, and a computer program product suitable for executing the method.

[0002] Known electrode type steam humidifiers are equipped with a steam cylinder with electrodes protruding inside. When the water supply is sufficiently filled and a sufficient voltage is applied to the electrodes, an electric current flows through the water, and ultimately the water boils and steam is generated. The decrease in water level due to the extracted steam is usually balanced by intermittently replenishing the tap water to a predetermined level when the water level drops to a certain extent. Except for the possibility of a maximum filling level sensor that limits the water intake to a specified level, the water level in the steam cylinder is generally adjusted based on the power consumed by steam generation.

[0003] The generated steam is pure, and since the mineral substances originally dissolved in the tap water remain in the steam cylinder, the concentration of the mineral components contained in the water in the steam cylinder increases. Mineral substances in solution are essential for the operation of an electrode type steam humidifier because they provide the necessary conductivity. However, this increase in mineral concentration has several significant drawbacks. The increase in mineral concentration leads to an increase in the conductivity of the water, which in turn leads to an increase in electrode corrosion and an increase in the formation of limescale.

[0004] To suppress these drawbacks and ensure the operability of the electrode type steam humidifier, it is necessary to regularly and completely drain the steam cylinder and replace the water with a high salt concentration with fresh tap water. The precipitated mineral residues also need to be removed regularly, for example, during the drainage process or during a regular maintenance cycle.

[0005] The object of the present invention is to provide an electrode type steam humidifier that at least reduces these drawbacks, an operation method of the electrode type steam humidifier, and a corresponding computer program product.

[0006] This object is solved by an electrode steam humidifier, a method, and a computer program product according to the independent claims. Preferred embodiments are the subject of the dependent claims.

[0007] The present invention thus comprises a steam container having a first water inlet for mineralized water and at least two electrodes arranged so that at least part of them is immersed in water filled above a minimum water level, and a voltage is supplied to the electrodes so that at least one of the electrodes has a different potential from the other electrodes and an electric current flows through the water. The steam container comprises a second water inlet for demineralized water and means for evaluating the conductivity of the water held in the steam container, and the flow rates through both water inlets for replenishing the steam container are controlled by a controller based on the evaluated conductivity in order to obtain or maintain a desired conductivity.

[0008] Furthermore, the present invention relates to a method of operating an electrode steam humidifier, which evaluates the conductivity of the water in the steam container of the steam humidifier and adjusts the conductivity of the water introduced into the steam container for replenishment so that the water mixture in the steam container has a desired conductivity.

[0009] The present invention also relates to a computer program product comprising a program part designed to execute the method of the present invention when read into a digital controller connected to at least the necessary sensors and actuators of an electrode steam humidifier.

[0010] Before a detailed description of the invention, some definitions of terms used in connection with the present invention are given.

[0011] If the potentials of the electrodes are generally and intentionally not the same, those electrodes have "different potentials", which is obvious when a voltage is directly applied to the electrodes. When an alternating voltage or a polyphase voltage is applied to the electrodes of an electrode steam humidifier, even if the potentials are temporarily the same during a cycle, since they are different in most of the cycle, the electrodes are still considered to have different potentials.

[0012] The present invention recognizes that by selectively replenishing water of different purities, the conductivity of the water held in the electrode steam humidifier can be controlled to a certain extent. As a result, it can operate with high efficiency over a longer operating cycle than conventional electrode steam humidifiers. In particular, by maintaining a predetermined mineralization of the water in the steam container at a predetermined level, electrode deterioration and mineral precipitation can be significantly reduced. Therefore, the maintenance cycle of the electrode steam humidifier according to the present invention can be significantly extended compared to what is common in the current state of the art.

[0013] To achieve this, the controller controls the inflow of mineral water (such as tap water) and demineralized water so that the desired conductivity of the water held in the steam container is obtained or maintained within at least a certain allowable range in order to counter the effects of steam extraction (which generally increases conductivity) and mineral precipitation (which generally decreases conductivity). The overall inflow rate and the mixing ratio of the inflow rates of mineral water and demineralized water are based on the conductivity evaluated for the water already present in the steam generator.

[0014] It has been found that by observing the system response to specific changes in the system state and taking into account specific system constants and specific estimations as necessary, the conductivity can already be evaluated at a sufficiently accurate level. Therefore, the means for evaluating the conductivity of the water held in the steam container preferably comprises an observation module capable of observing various parameters related to the operation of the electrode steam humidifier sufficient to evaluate the conductivity. The observation module may be integrated into the controller.

[0015] For example, when the steam container is filled for the first time and only mineral water is injected through the first water inlet or a predetermined mixed water of mineral water and demineralized water is injected through both water inlets up to a predetermined level, the response of the system when a predetermined voltage is applied to the electrodes can be regarded as the desired reference response.

[0016] By measuring the current generated by applying a specified voltage, the response of the system can be observed. As time passes, the system first shows an increase in conductivity in the form of an increase in current as it warms up until the water boils. Thereafter, as the water evaporates, the water level in the steam container gradually drops, the surface area of the electrodes immersed in the water decreases, and the current decreases. After the current reaches the lower limit value, when water with the initial conductivity is replenished into the steam container (for example, using only the water from the first inlet or the water from both inlets at the initially used mixing ratio), depending on the temperature of the incoming water, first by replenishment and then by the temperature rise caused by the current flowing through the water, the current increases again. Of course, depending on the choice of the lower limit value, the water replenishment can approximate a continuous water flow.

[0017] As described, since the change in mineralization of the water in the steam container (and the change in its conductivity) in the first cycle or the first few cycles is negligibly small, the response of the system in this first cycle or the first few cycles can be regarded as a reference response. This reference response may be stored, for example, in digital form as reference response data and made accessible to the controller and / or the observation module.

[0018] Assuming that the relevant environmental and system parameters (such as the mineral concentration of the mineral water and the demineralized water at the first and second inlets, the temperature of the incoming water, etc.) are constant, a detectable deviation from the reference response during operation indicates a change in the conductivity of the water in the steam container.

[0019] At that point, the mixing ratio of the mineral water and the demineralized water replenished into the steam container can be systematically adjusted so that the overall conductivity of the water in the steam container approaches the conductivity based on the reference response. The change in the mixing ratio can be defined, for example, by a characteristic curve (stored in digital form, for example) accessible to the controller and / or the observation module, or by a mathematical formula. It may also be derived from the modeling of the system.

[0020] As described above, it is possible to individually determine the reference response of each electrode type steam humidifier in its intended operating environment. Of course, it is also possible to provide previously created reference response data to the controller and / or observation module. The reference response data for a specific electrode type steam humidifier and / or its operating environment can be calculated or selected from an appropriate reference response data catalog based on specific parameters (e.g., the structural design of the electrode type steam humidifier, particularly the number and arrangement of electrodes, or the mineral concentration of the water supplied from the first water supply port).

[0021] Furthermore, the controller and / or observation module can be equipped with a machine learning algorithm that, over time, determines the most appropriate mixing adjustment when a deviation from the reference response occurs, starting, for example, from a predetermined characteristic curve for adjusting the mixing ratio of mineral water and demineralized water.

[0022] As explained, it is possible to control the conductivity of the water in the steam container by simply evaluating the system response during operation with sufficient accuracy. However, by utilizing additional sensor information, the control of conductivity can be further enhanced, and the dependence on indirectly determined or assumed values can be reduced. The additional sensor information is sent to the observation module and can be considered when evaluating the current system response compared to the reference response. Potentially, it is also possible to directly collect all relevant parameters for evaluating the conductivity of the water in the steam container with appropriate sensors. In this case, the observation module is omitted, and all measured values are directly processed by the controller.

[0023] The electrode type steam humidifier may preferably be provided with a sensor electrode indicating that the water level in the steam container is above a predetermined level. For this purpose, the tip of the sensor electrode is arranged at a predetermined level, and the detection value of the sensor depends on whether the tip of the sensor is immersed in the water or above the water surface. Such sensor electrodes are generally known in the prior art and have, for example, already been used as maximum water level indicators.

[0024] The switching between these two detection states of the sensor electrodes can be interpreted by the controller as a signal that the water level in the steam container has reached, is at, or is lower than a predetermined level. A deviation from the expected reference response of the system at this particular water level can be interpreted as being caused by other changes to the system, such as a change in the conductivity of the water.

[0025] When compensating for water loss due to steam generation, it is preferable to configure the sensor electrodes to detect the water level at which the steam container is regularly replenished. The sensor electrodes can also be used as an indicator to stop the inflow of water from the water supply port without affecting the above functions.

[0026] The sensor electrodes operate with high reliability in most cases. However, depending on the quality of the water used in the electrode-type steam humidifier, especially the quality of the mineral water at the initial water supply port, under certain circumstances, especially during replenishment or when the water is boiling, bubbles may occur in the steam container. Since bubbles can cause inaccurate readings of the sensor electrodes, in addition to or instead of the sensor electrodes, a water level detector that is free from or at least less prone to reading errors due to bubbles may be provided. Unlike the sensor electrodes, the water level detector can not only detect whether the water level is below or above a predetermined level, but also determine any water level within the measurement range. It can be one or more lead contacts actuated by a floating body in another container communicating with the steam, or a capacitance-type water level sensor as disclosed, for example, in DE 20 2016 005 944 U1. For example, to avoid or at least reduce any possible interference, such as the formation of bubbles in the water level detector, the detector is arranged in a container separate from the steam container, and the container forms communicating vessels. In such a configuration, the formation of bubbles when the water is boiling and other effects that may affect the measurement accuracy of the water level sensor are generally limited to the steam container and do not affect the water level sensor installed in another container.

[0027] In a preferred embodiment, the conductivity sensor may be provided in the steam container or a container communicating therewith. The sensor is preferably disposed at a position lower than the typical water level during normal operation of the electrode steam humidifier. By providing the conductivity sensor, it is not necessary to indirectly obtain the conductivity by measuring the current generated when a predetermined voltage is applied to the electrodes. Indirect measurement may be more likely to cause errors than direct measurement of conductivity, such as wear of the electrodes.

[0028] Alternatively or additionally, the conductivity sensor may be provided at one or both of the water inlets and / or at a position where the combined inflow of water where two separate inlets are joined and already mixed is provided. By disposing the conductivity sensor at the inflow section, the quality of the mineral water, demineralized water, and / or their mixed water can be observed and considered by the controller. For example, the inflow amounts through both inlets can be adjusted to obtain the desired conductivity of the mixed water.

[0029] Preferably, the electrodes and / or their number are optimized so that the electrode steam humidifier can make the conductivity of water as low as possible. Three electrodes are recommended when the steam output is up to 15 kg / h, and six electrodes are recommended when it is 20 - 65 kg / h. The surface area of the electrodes as a function of the rated current is preferably 5 - 30 cm 2 / A, more preferably 10 - 20 cm 2 / A in the case of full-surface electrodes, and preferably 5 - 25 cm 2 / A, more preferably 5 - 15 cm 2 / A in the case of mesh electrodes, but full-surface electrodes are preferred. The surface distance between two adjacent electrodes having different potentials is preferably 25 - 50 mm when the maximum rated potential difference is 400 V (e.g., generated by alternating current), 15 - 35 mm when the maximum rated potential difference is 200 V, and 50 - 80 mm when the maximum rated potential difference is 690 V.

[0030] The electrode type steam humidifier may be provided with a solenoid valve or a motor valve controllable by a controller at the first and / or second water inlets. Alternatively, when demineralized water is supplied from an external water treatment device, the electrode type steam humidifier may be provided with an interface to the external water treatment device connected to the second water inlet to control the demineralized water output of the water treatment device.

[0031] As already explained, when a voltage is applied to the electrodes, an electric current flows through the water, heating the water and changing its conductivity. The current will also increase until the water boils and the maximum value of steam production is achieved. When boiling occurs, steam is taken out, the water level in the steam container drops, and as a result, the amount of steam generated decreases. When the steam container is replenished, the cycle starts anew and the amount of steam generated increases to the maximum. Usually, in known electrode type steam humidifiers, depending on the actual design, the variation in steam generation over the entire replenishment cycle can be up to ±2.5% or ±10% around a predetermined set point pre-set by the structural configuration of the electrode type steam humidifier or by setting various process parameters such as voltage, maximum current, and / or power.

[0032] To reduce this variation, the controller is preferably configured to more finely control the steam generation of the electrode type steam humidifier.

[0033] For this purpose, the controller can be configured to adjust the power conducted through the electrodes. In particular, the controller can limit or mitigate the increase in current due to the increase in the conductivity of the water to adjust steam generation. This can avoid or at least reduce the overshoot of steam generation when boiling the water. Known techniques such as pulse width modulation (PWM), AC / AC conversion, leading-edge cutoff, trailing-edge cutoff, etc. can be used for power adjustment.

[0034] When there is a water level detection function, the controller may be configured to control steam production based on the water level corresponding to the immersion depth of the electrodes. The water level detector enables more accurate water replenishment compared to the sensor electrodes and reduces fluctuations in the water level during operation. Less fluctuation in the water level means less fluctuation in steam generation.

[0035] For an explanation of the method according to the present invention, generally refer to the above.

[0036] In the method of operating the electrode-type steam humidifier of the present invention, the conductivity of the water in the steam container of the steam humidifier is evaluated, and the evaluation may be based on the observation of the system response, direct measurement, and / or indirect measurement. The conductivity of the water introduced into the steam container for replenishment generally required during the operation of the electrode-type steam humidifier is adjusted so that the resulting mixture of water in the steam container has a desired conductivity. That is, if the conductivity of the water in the steam container is above the desired level, water with a lower conductivity is introduced for replenishment, and if it is below the desired level, water with a higher conductivity is introduced for replenishment. The conductivity of the water used for replenishment can be adjusted by mixing water from two water sources having different conductivities.

[0037] Preferably, the evaluation of the conductivity of the water in the steam container is based on the observation of at least one system response during the normal operation of the electrode-type steam humidifier. Observing the system response of the electrode-type steam humidifier generally enables the application of the method to existing electrode-type steam humidifiers and the design of electrode-type steam humidifiers without the need for structural changes. In many cases, to observe and respond to the system response, only the controller of the electrode-type steam humidifier needs to be updated.

[0038] The method of the present invention is preferably implemented in the electrode steam humidifier of the present invention, but is not limited to this specific embodiment. Rather, the method of the present invention may also be realized by a known electrode steam humidifier having a single water supply port and a water source connected thereto. In this case, the water source is controllable with respect to the mineralization of the water supplied to the electrode steam humidifier. An example of such a water source is a permeation unit for purifying mineral water, which has a controllable bypass for the mineral water.

[0039] Therefore, it is possible for the controller of the electrode steam humidifier to execute the method of the present invention, which can control an external controllable water source via an appropriate interface. Preferably, it is also possible for another controller to execute the method of the present invention. In this case, all the readings necessary for the execution of the above method must be provided to the said another controller, and it must be configured to control the electrode steam humidifier and all other possible components via an appropriate interface. In other words, the controller that executes the computer program product of the present invention needs to be connected to all the necessary sensors and actuators of the electrode steam humidifier, as well as all other possible components.

Brief Description of the Drawings

[0040] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The following are shown in the drawings.

[0041]

FIG. 1

Embodiments for Carrying Out the Invention

[0042] FIG. 1 schematically shows an electrode steam humidifier 1 according to the present invention. By describing the electrode steam humidifier 1, not only the device of the present invention but also the method of the present invention can be easily clarified.

[0043] The electrode type steam humidifier includes a steam container 1. The steam container 1 includes a steam container 2 in the shape of a steam cylinder. The steam container 2 includes a suction port 3 and a drain port 4 having a controllable drain pump 4' at its bottom. There is a steam outlet 5 at the upper part, which is connected to other devices (not shown) that require steam at least temporarily, such as an air conditioning control unit.

[0044] Inside the steam container 2, six electrodes 6 are arranged at equal intervals in the circumferential direction. These electrodes 6 are configured to be able to boil water with limited conductivity, and thus have large surfaces facing each other (in this case, each about 20 cm 2 / A). The electrodes 6 are depicted as simple plate-shaped electrodes, but may have a more complex design, such as V-shaped, etc. As a result, the surfaces of two adjacent electrodes 6 can maintain a constant distance over the entire area.

[0045] The electrodes 6 are individually electrically connected via connection lines 8 to a power distribution unit 7 connected to an external power source, such as a power grid (not shown). The power distribution unit 7 is configured to supply a DC or AC voltage to the electrodes such that the potentials of two adjacent electrodes 6 are different. Furthermore, the power distribution unit 7 measures the total current flowing between the electrodes 6 and provides a function of limiting the current flow (and thus the power consumed by the electrodes 6 assuming a constant voltage) to a set value supplied from the outside.

[0046] Via a Y-shaped connector 9, the suction port 3 is connected to two separate water supply ports 10, 11, and the flow rate thereto is controllable by solenoid valves 12, 13 in this example. The first water supply port 10 is usually for mineral water, which is tap water, and the other water supply port 11 is for demineralized water.

[0047] A conductivity sensor 14 for measuring the conductivity of the water passing through the connection part is provided at the connection part between the Y-shaped connector 9 and the suction port 3.

[0048] In addition, the steam container 2 is provided with a sensor electrode 15 that protrudes a predetermined length from its upper part. The sensor electrode 15 detects whether the tip thereof is immersed in water or not.

[0049] In parallel with this, a water level detector 16 is provided. The water level detector 16 connected to the steam container 2 via a connecting pipe is, for example, a capacitance type water level sensor as disclosed in DE 20 2016 005 944 U1, and can accurately determine the water level in the steam container 2 within a range near the water level defined by the sensor electrode 15. This range is mainly determined by the length of the water level detector 16.

[0050] That is, the conductivity sensor 14 having the ability to measure the total current, the sensor electrode 15, the water level detector 16, and the power distribution unit 7, as well as all controllable devices, that is, various valves 12 and 13, the drainage pump 4', and the power distribution unit 7 related to the power limiting function, are connected to the controller 20, and the controller 20 also includes an observation module 21.

[0051] For operation, first, by opening the two solenoid valves 12 and 13 of the two water inlets 10 and 11, the steam container 2 is filled with water of a predetermined conductivity up to the water level defined by the sensor electrode 15. Here, the controller 20 opens each valve 12, 13 to the extent necessary to achieve a mixture of the desired conductivity. The predetermined conductivity of the water flowing in during filling is constantly monitored via the conductivity sensor 14. When deviating from the desired conductivity, the controller 20 adjusts the valves 12, 13 and is configured to adjust the mixture of mineral water and demineralized water to reach the desired conductivity.

[0052] When the sensor electrode 15 and / or the water level detector 16 sends a signal to the controller 20 indicating that a predetermined water level has been reached, the valves 12, 13 are closed.

[0053] After the steam container 2 is initially filled with water, the electrodes 6 are energized by the power distribution unit 7, and adjacent electrodes 6 have different potentials, and an electric current is generated in the water due to the conductivity of the water. The total current is measured by the power distribution unit 7 and reported to the controller 20.

[0054] When an electric current flows through the water, the water is heated and boils, generating steam, which is discharged from the steam outlet 5. During heating, the conductivity of the water increases, and the increase in the current passing through the electrodes 6 is recorded by the power distribution unit 7 and the controller 20.

[0055] By steam extraction, the water level in the steam container 2 drops, which is detected by the sensor electrode 15 and / or the water level detector 16, and generally leads to a decrease in current. The drop in the water level is recorded by the controller 20 by a combination of the sensor electrode 15 reporting that the water level is below the tip of the electrode and a decrease in the current by a predetermined amount, or by the water level detector 16, and is generally addressed by replenishing water from the first and / or second water inlets 10, 11 into the steam container 2.

[0056] Since the generated steam is generally pure, the mineral concentration of the water in the steam container 2 generally (albeit slowly) increases and initially also contributes to the increase in conductivity. However, as mineralization progresses, it results in the precipitation of minerals, and as a result, the conductivity of the entire water may decrease. Intending to maintain the conductivity of the water in the steam container 2 at a predetermined / initial level, the controller 20 is configured to intentionally adjust the conductivity of the inflowing water to control the conductivity of the resulting water mixture in the steam container 2.

[0057] For this reason, the controller 20 includes an observation module 21 configured to evaluate the conductivity of the water in the steam container 2.

[0058] For example, after the steam container 2 is replenished with water as indicated by the sensor electrode 15, the observation module 21 may observe the maximum current reached each time. This maximum current is the maximum current reached after heating the water in the steam container 2 to the boiling temperature. For example, a deviation from the current measured during the initial heating cycle (see above), which may be regarded as the reference response of the system of the electrode type steam humidifier 1, may be interpreted as a deviation in the conductivity of the water in the steam container 2, and can be addressed by the controller 20 by adjusting the mixture of mineral water and demineralized water used for replenishment according to the characteristic curve stored in the controller 20.

[0059] Alternatively or additionally, the conductivity of the water in the steam container 2 can be derived from the current measured by the power distribution unit 7 and the water level detected by the water level detector 16. These results may be compared with the expected standard system response stored in the controller, and any deviation can be interpreted as a deviation from the desired conductivity of the water in the steam container 2. Also in this case, the controller 20 may address this deviation by adjusting the mixture of mineral water and demineralized water used for replenishment according to the characteristic curve stored in the controller 20.

[0060] Since the conductivity of the water mixture flowing into the steam container 2 is monitored by the conductivity sensor 14, the controller 20 and / or the observation module 21 may apply a machine learning algorithm based on the measured conductivity value and the impact on the conductivity evaluated for the water in the steam container 2.

[0061] In any case, based on one or both of the above methods, i.e., based on the sensor electrode 15 and the water level detector 16, the controller 20 can keep the mineral concentration of the water in the steam container 2 substantially constant during the operation of the electrode type steam humidifier 1.

[0062] For this reason, although the period during a complete replacement of water in the steam container 2 and other maintenance cycles may be extended, it is necessary to sometimes completely clean the steam container 2 in order to wash away as much as possible the accumulation of minerals that precipitate. For this purpose, the controller 20 may operate the drain pump 4' to suck up water from the steam container 2 through the drain port 4. When the steam container 2 becomes empty, the drain pump 4' is stopped and the steam container 2 is replenished with water as described above.

[0063] The electrode type steam humidifier 1 shown in FIG. 1 can provide additional advantages.

[0064] By evaluating the water level or at least evaluating that a predetermined water level has been reached, that is, by using both of the disclosed techniques via the sensor electrode 15 and the water level detector 16, the formation of bubbles in the steam container 2 can be detected. This is because usually, before the actual water level detectable by the water level detector 16, which is not affected by the formation of bubbles in the steam container 2, reaches the tip of the sensor electrode 15, the bubbles in the steam container 2 trigger the sensor electrode 15. The formation of bubbles in the steam container 2 may indicate that the water (mineral water which is usually tap water) contains impurities or has poor water quality, and in order to ensure the long-term operation of the electrode type steam humidifier 1, more frequent maintenance and / or cleaning of the electrode type steam humidifier 1, particularly the steam container 2 and the electrode 6, may be required.

[0065] In order to reduce the variation in steam generation, the controller 20 may be configured to transmit appropriate control commands to the power distribution unit 7 and use the water level detector 16 to keep the water level in the steam container 2 as close as possible to the desired water level defined by, for example, the sensor electrode 15, thereby mitigating the increase in the power conducted through the electrode 6. Both means help to keep the steam generation of the electrode type steam humidifier 1 more constant.

[0066] The present disclosure includes the following aspects.

[0067] <1> A steam container (2) having a first water inlet (10) for mineral water, At least two electrodes (6) arranged so that at least a part thereof is immersed in water filled above the lowest water level, A voltage is supplied to the electrodes (6) so that at least one of the electrodes (6) has a potential different from that of the other electrodes (6) to generate an electric current in water. The steam container (2) A second water inlet (11) for demineralized water, Means for evaluating the conductivity of the water held in the steam container (2), An electrode type steam humidifier (1), characterized in that the flow rates through both water inlets (10, 11) for replenishing the steam container (2) are controlled by a controller (20) based on the evaluated conductivity in order to obtain or maintain a desired conductivity.

[0068] <2> The means for evaluating the conductivity of the water held in the steam container (2) includes an observation module (21) capable of observing at least one operating parameter of the electrode type steam humidifier (1) sufficient for evaluating the conductivity. The electrode type steam humidifier according to <1>.

[0069] <3> The at least one operating parameter includes an electric current flowing through the electrode (6). The electrode type steam humidifier according to <2>.

[0070] <4> An electrode type steam humidifier according to any one of claims <1> to <3>, provided with a sensor electrode (15) indicating that the water level in the steam container (2) is above a predetermined level.

[0071] <5> A water level detector (16) is provided. Preferably, the water level detector (16) is arranged in a container separate from the steam container (2), and the container forms a communicating container. The electrode type steam humidifier according to any one of <1> to <4>.

[0072] <6> At least one conductivity sensor (14) is provided in the steam container (2), in a container communicating with the steam container (2), in one or both of the water inlets (10, 11), and / or at a position providing a composite inflow of water already mixed by combining two separate inlets (10, 11) into the steam container (2). The electrode type steam humidifier according to any one of <1> to <5>.

[0073] <7> The surface area of each electrode (6) as a function of the rated current is 5 to 30 cm in the case of a full-surface electrode 2 / A, preferably 10 to 20 cm 2 / A, 5 to 25 cm in the case of a mesh electrode 2 / A, more preferably 5 to 15 cm 2 / A, and / or the surface distance between two adjacent electrodes (6) having different potentials is 25 - 50 mm when the maximum rated potential difference is 400 V, 15 - 35 mm when the maximum rated potential difference is 200 V, and 50 - 80 mm when the maximum rated potential difference is 690 V, the electrode type steam humidifier according to any one of <1> to <6>.

[0074] <8> The electrode type steam humidifier according to any one of <1> to <7>, wherein electromagnetic valves (12, 13) controllable by the controller (20) are provided at the first water supply port and / or the second water supply port (10, 11).

[0075] <9> The electrode type steam humidifier according to any one of <1> to <8>, wherein the electrode type steam humidifier (1) includes an interface to an external water treatment device connected to the second water supply port (11) for controlling the demineralized water output of the water treatment device.

[0076] <10> The electrode type steam humidifier according to any one of <1> to <9>, wherein the steam container (2) is a steam cylinder.

[0077] <11> The controller (20) is configured to adjust the power conducted through the electrode (6), and preferably is configured to limit or mitigate the increase in current due to an increase in the conductivity of the water in the steam container (2), the electrode type steam humidifier according to any one of <1> to <10>.

[0078] <12> The controller (20) is configured to control the first and second water supply ports (11) depending on the water level detector (16) so as to keep the water level in the steam container (2) constant during operation, the electrode type steam humidifier according to any one of <5> to <11>.

[0079] <13> Evaluating the conductivity of the water in the steam container (2) of the electrode type steam humidifier (1), A method of operating an electrode type steam humidifier (1) for adjusting the conductivity of the water introduced into the steam container (2) for replenishment so that the mixture of water in the steam container (2) has a desired conductivity.

[0080] <14> The evaluation of the conductivity of the water in the steam container (2) is based on the observation of at least one system response during normal operation of the electrode type steam humidifier, the method according to <13>.

[0081] <15> A computer program product including a program portion designed to execute the method according to <13> or <14> when read into a digital controller connected to at least the necessary sensors and actuators of the electrode type steam humidifier (1).

Claims

1. A steam container (2) having a first water inlet (10) for mineral water, and at least two electrodes (6) arranged so that at least a part thereof is immersed in water filled above the lowest water level, characterized in that: A voltage is supplied to the electrodes (6) so that at least one of the electrodes (6) has a potential different from that of the other electrodes (6) to generate an electric current in water, The steam container (2) is provided with a second water inlet (11) for demineralized water, and means for evaluating the conductivity of the water held in the steam container (2), The flow rates through both water inlets (10, 11) for replenishing the steam container (2) are controlled by a controller (20) based on the evaluated conductivity in order to obtain or maintain a desired conductivity. Electrode type steam humidifier (1).

2. The means for evaluating the conductivity of the water held in the steam container (2) includes an observation module (21) capable of observing at least one operating parameter of the electrode type steam humidifier (1) sufficient to evaluate the conductivity. The electrode type steam humidifier according to claim 1.

3. The at least one operating parameter includes an electric current flowing through the electrodes (6). The electrode type steam humidifier according to claim 2.

4. A sensor electrode (15) is provided which indicates that the water level in the steam container (2) is at a predetermined level or higher. The electrode type steam humidifier according to any one of claims 1 to 3.

5. A water level detector (16) is provided. Preferably, the water level detector (16) is arranged in a container separate from the steam container (2), and the container forms a communicating container. The electrode type steam humidifier according to any one of claims 1 to 3.

6. At least one conductivity sensor (14) is provided inside the steam container (2), inside a container communicating with the steam container (2), one or both of the water inlets (10, 11), and / or two separate inlets (10, 11) are combined to provide a composite inflow of water already mixed into the steam container (2). The electrode type steam humidifier according to any one of claims 1 to 3.

7. The surface area of each of the electrodes (6) as a function of the rated current is 5 to 30 cm ２ / A, preferably 10 to 20 cm ２ / A, and in the case of a mesh electrode is 5 to 25 cm ２ / A, more preferably 5 to 15 cm ２ / A, and / or the surface distance between two adjacent electrodes (6) having different potentials is 25 to 50 mm in the case of a maximum rated potential difference of 400 V, 15 to 35 mm in the case of a maximum rated potential difference of 200 V, and 50 to 80 mm in the case of a maximum rated potential difference of 690 V. The electrode type steam humidifier according to any one of claims 1 to 3.

8. An electromagnetic valve (12, 13) controllable by the controller (20) is provided in the first water inlet and / or the second water inlet (10, 11). The electrode type steam humidifier according to any one of claims 1 to 3.

9. The electrode steam humidifier (1) according to any one of claims 1 to 3 includes an interface to an external water treatment device connected to the second water inlet (11) in order to control the demineralized water output of the water treatment device.

10. The steam container (2) of the electrode steam humidifier according to any one of claims 1 to 3 is a steam cylinder.

11. The controller (20) is configured to adjust the power conducted through the electrode (6), and preferably is configured to limit or mitigate an increase in current due to an increase in the conductivity of the water in the steam container (2). The electrode steam humidifier according to any one of claims 1 to 3.

12. The controller (20) is configured to control the first and second water inlets (11) depending on the water level detector (16) so as to keep the water level in the steam container (2) constant during operation. The electrode steam humidifier according to claim 5.

13. Evaluating the conductivity of the water in the steam container (2) of the electrode steam humidifier (1), A method of operating an electrode steam humidifier (1) for adjusting the conductivity of the water introduced into the steam container (2) for replenishment so that the mixture of water in the steam container (2) has a desired conductivity.

14. The evaluation of the conductivity of the water in the steam container (2) is based on the observation of at least one system response during normal operation of the electrode steam humidifier. The method according to claim 13.

15. A computer program product including a program portion designed to execute the method according to claim 13 or 14 when read into a digital controller connected to at least the necessary sensors and actuators of the electrode steam humidifier (1).

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