JPS6210682B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water generation device that produces water from moisture in the air, and more specifically, a water generation device that has an added function to control a desorption operation that extracts water vapor from a solid moisture absorbent that has captured moisture in the air. Regarding. Conventional fresh water production equipment includes seawater desalination equipment that uses seawater distillation, reverse osmosis using special diaphragms, and ion exchange methods, which are beginning to be put into practical use in regions with particularly poor water conditions. These devices are mainly aimed at supplying drinking water, but in order to provide water for human daily life other than drinking water, sewage is subjected to biological treatment such as activated sludge method and contact oxidation method, as well as activated carbon adsorption and ozone oxidation treatment. So-called advanced wastewater treatment equipment has also been developed, which purifies wastewater through physicochemical treatments such as the following. However, all of these water production devices only obtain high-quality water from poor-quality water, and since they use liquid water as raw material, it is natural that they cannot obtain completely liquid water like in deserts. By the way, we can't produce water. Therefore, there is a need for a water generating device that can easily obtain water even in areas such as deserts where liquid water cannot be obtained. This invention is being developed in response to the above-mentioned demands.
The object of the present invention is to enable effective automatic control of the desorption operation of the moisture absorbent in a completely new fresh water production apparatus that obtains water by desorbing this moisture. FIG. 1 is a system diagram showing the configuration of an embodiment of the present invention. In the diagram, 1 is an adsorption/desorption tank (hereinafter referred to as
It is abbreviated as "tank". ), 2 is a bed filled with a solid moisture absorbent such as a molecular sieve or silica gel provided in the tank 1 (hereinafter abbreviated as "hygroscopic agent layer"), 3 is a heater, and 4 is a bed for supplying thermal energy to the heater 3. A supply heat source, 5 a circulation fan for circulating the gas in the tank 1, 6 a temperature detector, 7 an on-off valve provided in the passage of the circulating gas (indicated by arrow A) in the tank 1, 8
is a condenser, 9 is a conduit connecting tank 1 and condenser 8, 1
0 is a valve provided in this conduit 9, 11 is an inlet for outside air containing moisture, 12 is an outlet for air whose moisture has been adsorbed by the moisture absorbent layer 2, and 13 and 14 are an inlet 11 and an outlet, respectively. 15 is a controller that electrically controls the operation of each movable part, and 6 is an electrical connection connecting the controller 15 and each movable part. In this example device, first, in the adsorption process,
The on-off valves 13 and 14 are opened, the on-off valve 7 of the circulation path is closed, and outside air is introduced as indicated by the broken line arrow B in the figure, and the moisture contained therein is adsorbed into the moisture absorbent layer 2. FIG. 1 shows the state of the desorption process after the adsorption process is completed. The on-off valves 13 and 14 are closed, and the on-off valve 7 of the circulation path is open. The circulating gas discharged by the circulation fan 5 comes into contact with the heater 3 and is heated up, and then introduced into the moisture absorbent layer 2 . While the circulating gas passes through the hygroscopic layer 2, most of the heat obtained from the heater 3 is spent on desorbing the moisture adsorbed on the hygroscopic layer 2 and increasing the temperature of the hygroscopic layer 2. While its own temperature decreases, it is again circulated to the suction side of the circulation fan 5, taking with it the desorbed water vapor. The temperature of the desiccant layer 2 is monitored by a temperature detector 6 at the lowest layer downstream of the circulating gas. In this way, the pressure of the circulating gas in the tank 1 is increased by the amount of evaporated water, and the increased amount is pushed out to the condenser 8 through the conduit 9 as shown by arrow C, where it is cooled and converted into liquid water. and is supplied to the outside of the system as shown by arrow D.
When a certain amount of heat is supplied to the heater 3, the temperature of the moisture absorbent layer 2 and the amount of water taken from the condenser 8 increase over time. FIG. 2 shows a measurement example of a desorption curve when silica gel is used as a moisture absorbent, and FIG. 3 shows a measurement example of a desorption curve when a molecular sieve is used. In the figure, the solid curve represents the temperature measured by the temperature detector 6, and the dashed-dotted curve represents the cumulative amount of water intake at the outlet of the condenser 8. The operating conditions of the fresh water generator at that time are as shown in the table below.

[Table] In Fig. 2, in the region where the temperature indicated by the temperature detector 6 is above a plateau (region where the temperature is constant), the relationship between the temperature and the amount of water intake remains almost constant even if the amount of heat from the heater 3 changes. . For example, when the temperature is 130℃, the amount of water intake is 135-140g, and when the temperature is 220℃, it is 165-170g.
It is. Also, from the figure, the maximum possible water intake amount is
It can be seen that to obtain 85% or more, the temperature needs to be about 170°C or more, and to obtain 90% or more, the temperature needs to be about 180°C or more. Note that, if silica gel is heated above 350°C, it will generally sinter and its moisture absorption capacity will decrease, so it is necessary to maintain the temperature below 350°C. Even when the moisture absorbent molecular sieve is used, as shown in FIG. 3, the relationship between temperature and water intake amount is almost independent of the amount of heat from the heater 3 in the temperature range above the plateau. According to the figure, it is clear that to obtain 85% or more of the maximum water intake, the temperature should be set to about 220°C or higher, and to obtain 90% or more of the maximum water intake, the temperature should be set to about 280°C or higher.
In addition, the moisture absorption capacity of molecular sieves generally decreases when heated above 500°C, so the temperature should not be increased to 500°C.
It is necessary to maintain the following: In this way, when the temperature detected by the temperature detector 6 reaches a predetermined temperature, the desorption can be considered to have been completed. The temperature is determined taking into consideration the target water intake amount and economic efficiency, and for silica gel it is 180 to 250 degrees Celsius, and for molecular sieve it is 220 to 400 degrees Celsius.
There is an optimum value within the range of °C. Therefore, in the fresh water generator of the present invention, the desorption process is considered to be completed when the temperature of the lower part of the moisture absorbent layer 2 reaches the above-mentioned predetermined temperature, and the controller 15 that receives the temperature signal Automatically performs the necessary operations to move the water device to the next adsorption process.
That is, the on-off valves 13 and 14 are opened, the operation of the circulation fan 5 and the heater 3 is stopped, and the valve 10 is closed.
Then, the circuit switch 7 of the circulation path is closed, and an adsorption fan (not shown) is operated to introduce outside air into the tank 1 for a certain period of time as indicated by the broken line arrow B in the figure. As mentioned above, in the embodiment, the temperature sensor 6 is inserted into the bottom of the moisture absorbent layer 2, but the insertion point is not limited thereto, and between the bottom of the adsorbent layer 2 and the heater 3. Any path for circulating gas may be used. The temperature detector 6 may be a normal thermocouple, or may be a thermistor or other heat-sensitive resistor. The heat source 4 is preferably of an oil combustion type and supplies combustion exhaust smoke to the heater 3 from an economical point of view, but in the case of a small fresh water generator, it may be of an electric heating type. The hygroscopic agent is not particularly limited to the silica gel and molecular sieve exemplified here; other solid hygroscopic agents such as activated alumina and activated clay may also be used, and lithium bromide,
A porous carrier such as activated carbon or alumina may be impregnated with an aqueous solution of a moisture absorbent such as lithium chloride or glycerin. As described in detail above, in the fresh water generating apparatus of the present invention, a temperature detector is provided in the circulation path of the desorption gas that circulates through the solid moisture absorbent heated during the desorption process, so that the temperature detected by this Therefore, the substantial completion of the desorption process can be determined without waste, and furthermore, by switching to the adsorption process based on this, it is possible to expect an improvement in the water generation efficiency.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing the configuration of an embodiment of the present invention, Fig. 2 is a curve diagram showing an example of measurement of desorption characteristics when silica gel is used as a hygroscopic agent, and Fig. 3 is a diagram showing a measurement example of desorption characteristics when silica gel is used as a hygroscopic agent. FIG. 3 is a curve diagram showing an example of measurement of desorption characteristics when In the figure, 2 is a moisture absorbent layer, 3 is a heater, 5 is a circulation fan, 6 is a temperature detector, 8 is a condenser, and arrow A is a circulating gas.

Claims (1)

[Scope of Claims] 1. Water is obtained by adsorbing moisture in a gas to a moisture absorbent during the adsorption process, heating the moisture absorbent to desorb the adsorbed moisture during the desorption process, and condensing the resulting water vapor. further comprising a temperature detector disposed in the circulation path of the desorption gas circulating through the heated moisture absorbent during the desorption process, and when the temperature detected by the temperature detector reaches a predetermined value, A freshwater generating apparatus characterized in that the completion of the desorption process is determined by this and the switch is made to the adsorption process. 2. Silica gel or a moisture absorbent with similar properties is used as the moisture absorbent, and when the temperature detected by the temperature detector reaches a predetermined temperature within the range of 180℃ to 250℃, the process is switched to the adsorption process. A freshwater generator according to claim 1, characterized in that: 3 Use Molecular Sieve or a zeolite-based moisture absorbent with similar properties as the moisture absorbent, and switch to the adsorption process when the temperature detected by the temperature detector reaches a predetermined temperature within the range of 220℃ to 400℃. A freshwater generating device according to claim 1, characterized in that: