JP2005118760A - Apparatus for generating saturated gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for generating saturated gas, which is constituted so that the water put in a vessel is heated by a heating means, a gas is then put in the vessel, dispersed in the hot water and brought into contact with the hot water and the hot water-contacted gas is withdrawn from the vessel as the gas containing saturated steam of the objective temperature, thereby the saturated gas having a precise dew point can be obtained. <P>SOLUTION: This apparatus for generating saturated air is provided with a saturation tank 1, an intermediate mesh 4 arranged at the vertically intermediate position of the saturation tank 1, a second heating unit 5 and a heating unit 2 arranged respectively in the upper and lower sections 1a and 1b and a water replenishing pipe 13. The water in the lower section 1b is heated by the heating unit 2 to the temperature higher than the temperature t<SB>2</SB>of the objective saturated air which is to heated by the second heating unit 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, the water contained in the container is heated by the heating means, and the gas is put into the container, the gas is dispersed in the water, and the water is brought into contact with the water to bring the gas into a saturated steam at a target temperature. The present invention relates to a saturated gas generator that is made into a contained gas and taken out from the container.

As a conventional saturated gas generator, for example, a one-stage saturated tank is placed in a constant temperature bath in which water at a constant temperature of 60 ° C. is placed, and a heat exchanger is placed in the water tank, and the supplied gas is First, the water is passed through a heat exchanger and preheated to 60 ° C. with water in the water tank, and the temperature of the upper part is detected by a temperature detection hot contact provided at the upper part of the saturation tank so that the temperature is controlled to 60 ° C. A heater is installed in the lower part of the saturation tank, and a gas heated to 60 ° C. is introduced from the lower part of the saturation tank while being brought into contact with the water in the tank. In the process, water vapor evaporated from the water is taken into saturated air, There is shown a saturated gas generator in which target saturated air at 60 ° C. is taken out from the upper part of the saturation tank (see Patent Document 1). In this conventional apparatus, saturated air having a dew point of approximately 60 ° C. was obtained by preheating the gas and putting it in the saturation bath and controlling the upper temperature of the saturation bath to the target 60 ° C. .
No. 6-34819 (Fig. 1 and related explanation)

  On the other hand, in such a saturated air generator, since air is taken in and sent out from the water vapor, the water level in the saturation tank is lowered. Therefore, although not shown in this patent document, it is usually automatically controlled by water level control in the saturation tank. Water is being replenished. This water is introduced from the lower position of the saturation tank so that it is heated. When water is added, the water temperature of the portion decreases, and in the saturation tank, the convection and the air lift force that bubbles raise the water Since the influence of the water circulates on the entire saturation tank, the water temperature tends to drop below the set temperature even in the upper part of the saturation tank where the temperature is detected. As a result, there is a problem that the dew point temperature of the saturated air is lowered and the accuracy is deteriorated.

  Further, as described above, since air absorbs water vapor from water and becomes saturated air, the water around the water that evaporates and becomes water vapor decreases in temperature to supply latent heat to the water vapor. Therefore, even if the temperature of the upper part is detected and controlled, due to the large distance between the position of the heater and the position of the detection unit and the variation in the evaporation state of water between them, Even at the top, the effect of a drop in water temperature due to latent heat is inevitable. As a result, there is also a problem that the dew point temperature is inaccurate at this point.

  Even if the gas to be taken in is preheated to 60 ° C. as described above and the temperature of the gas when entering the saturation tank is 60 ° C. which is the same as that of water, water vapor evaporated from water at that temperature is taken in. Therefore, as described above, the surrounding water releases the latent heat of vaporization of the water vapor, so that the temperature is lowered and eventually the dew point temperature is affected and the accuracy is deteriorated.

  Then, this invention makes it a subject to solve the said problem in a prior art, and to provide the saturated gas generator which can obtain the saturated gas of a dew point temperature with sufficient precision.

In order to solve the above-mentioned problems, the present invention is characterized in that the water in a container is heated by a heating means and a gas is put into the container to disperse the gas in the water. In a saturated gas generator in which the gas is brought into a saturated water vapor-containing gas at a target temperature and brought out of the container by contacting with the gas,
A porous member provided to restrict the passage of the gas at an intermediate position in the vertical direction of the container, and the gas is set to the target temperature in an upper portion of the porous member of the container. A heat exchanging means provided in the container, wherein the heating means is provided in a lower portion of the porous member of the container.

  According to a second aspect of the present invention, in addition to the above, the heating means can heat the gas to a temperature that is higher than the target temperature and can be restored to the target temperature by the heat exchange means. It is characterized by being.

  According to a third aspect of the present invention, in addition to the features of the first or second aspect of the present invention, before the gas is put into the container, the gas is supplied with an amount of heat up to the latent heat of the saturated water vapor, and the gas is used for the purpose. Preheating means is provided that enables heating to a temperature higher than the above temperature.

  As described above, according to the present invention, in the first aspect of the present invention, the porous member is provided at the middle position in the vertical direction of the container so as to restrict the passage of gas, and the upper part of the porous member in the container is provided. Since the heat exchange means is provided so that the gas reaches the target temperature and the heating means is provided in the lower part of the porous member, the heat exchange means is heated up and down through the porous member in the container. Alternatively, there is a cooling part and a heating part of the heating means, which can heat or cool the water further on the upper side after heating the water on the lower side.

  On the other hand, since the gas is dispersed and put in water, it becomes small bubbles and rises by buoyancy to reach the position of the porous member. At this time, in order to restrict the passage of the gas, that is, by setting the pores of the porous member to an appropriate size in relation to the size of the bubbles, for example, many of the small bubbles form the porosity of the porous member. The rise is temporarily restricted when hitting a member such as a wire. As a result, in the lower part of the container, the water that rises due to the lifting force of a large number of small bubbles that rise or rise due to heating and convection is restricted from rising at the position of the porous member. It flows only in the lower part of the porous member. And it heats with a heating means so that the water of a lower part is equalized and temperature distribution becomes good.

  As a result, in the upper part of the porous member, convection occurs only in the upper part independently of the lower part due to heating or cooling of the water by the heat exchange means, and the temperature of the water is made uniform.

  In such a state, if the water in the container is evaporated in order to make the gas into a saturated water vapor-containing gas, the water is insufficient thereby, so that the insufficient water is replenished. Since this replenishing water is normally replenished to the lower part with normal temperature water, the water temperature of the lower part is suddenly changed. However, since water convects independently above and below the porous member as described above, the upward influence of temperature disturbance due to water supply to the lower portion is prevented. Above, the function of bringing the gas to the target temperature is maintained by the heat exchange means. As a result, even when water is replenished, a saturated gas having a target temperature can be obtained with high accuracy.

  In the invention of claim 2, since the heating means is configured to be able to heat to a temperature higher than the target temperature of water, the lower part of the porous member is higher than the target temperature of the gas contained It can be a saturated gas at temperature. When this gas enters the upper part, water is at that temperature so that the upper part is brought to the target temperature by the heat exchanging means, so the gas containing water vapor supersaturated with respect to that temperature Will release supersaturated water vapor into the water. In this release of water vapor into the water, water in direct contact with the water vapor condenses the water vapor, so that the supersaturated water vapor can be easily and reliably removed from the gas. As a result, it is possible to make the gas a saturated gas having a target temperature with extremely high accuracy.

  In the invention of claim 3, in addition to the invention of claim 1 or 2, a preheating means is provided and, for example, normal air is put into the container as a gas to be made into a saturated steam-containing gas at a target temperature. Before, the amount of heat up to the latent heat of saturated water vapor is supplied to normal air so that the gas can be heated to a temperature higher than the target temperature, so by operating the preheating means by human operation or automatic operation When the target temperature is up to about 50 ° C., for example, the air is preheated to a temperature sufficiently higher than the target temperature with the amount of heat of the latent heat, and is then placed in a container and dispersed in water. After contact with water, it can be removed from the container.

  In this case, since the latent heat of saturated water vapor occupies most of the total amount of heat, normal air that has been supplied with this heat and preheated is saturated water that has been heated to the temperature of saturated water vapor, which is the target temperature. However, the temperature rises to a considerably high temperature. And when water is heated to the target temperature or higher by the heating means, when such heated air comes into contact with the water, the temperature is high when a part of the water evaporates. The latent heat required for evaporation is supplied from the heated air to the water side.

  As a result, when a part of the heated water evaporates, the surrounding water does not lose a large amount of heat of latent heat, and a rapid temperature drop of the water is prevented, and the water whose temperature is adjusted by the heating means The temperature is maintained without being disturbed. As a result, the temperature accuracy of the water in the lower part of the porous member is improved, so that saturated air at the target temperature can be obtained more accurately in the upper part.

  On the other hand, when the target temperature exceeds about 60 ° C., the amount of saturated water vapor contained in the air increases abruptly. However, the preheating temperature becomes too high and the preheating means becomes larger and the handling of the equipment becomes worse due to the high temperature of the gas. Will be heated.

  However, even in this case, since the temperature of the gas is considerably higher than the target temperature, the evaporation of water contained in the container is promoted, the gas reaches the saturated gas quickly, and the gas-liquid in the container A contact time can be shortened and a container can be reduced in size.

FIG. 1 shows a configuration example of a saturated air generator as a saturated gas generator to which the present invention is applied.
The saturated air generating apparatus heats water, which is put up to the water surface L in a saturation tank 1 that is a container, with a heating apparatus 2 that is a heating means, and also supplies air as gas to the saturation tank 1 from an air supply pipe 3. This is dispersed in water, brought into contact with water, and the air rising in the water is made into saturated air A ₂ at temperature t ₂ , which is a saturated water vapor-containing gas at saturation temperature t ₂ , which is the target temperature. The apparatus is designed to be taken out from the saturation tank 1 and has an intermediate mesh 4 as a porous member and a second heating device 5 as a heat exchange means.

Such a saturated air generating apparatus has a fine mesh 12 as a normal component part, in which air introduced from the bottom 11 as a bottom part is uniformly dispersed over the entire cross section of the saturation tank 1 to be sent as small bubbles, Water supply pipe 13, water supply valve 14, water surface sensor 15, water level controller 16 for controlling water supply valve 14 so as to maintain the water surface in the vicinity of level L by this sensor signal, in order to eliminate bubbles generated from the water surface And the outlet pipe 19 for taking out the saturated air A ₂ from the upper end plate 18 which is the upper part.

Intermediate mesh 4 is limited to the height of a little above the center position in the vertical, the passage when the air was put rises by buoyancy become small bubbles as the intermediate position L ₁ of the vertical saturator 1 It is provided to do. That is, the intermediate mesh 4 is formed such that a substantial part of the rising small bubbles hits the mesh line and passes after being caught by the mesh. Such a mesh size is determined by various conditions such as the size of small bubbles formed by the fine mesh 12, the amount and pressure of supply air, the size of the saturation tank, the wire diameter of the mesh, and the like, for example, about 1 mm square. Sized.

  As the porous member, instead of such a mesh, it is composed of a thin layer of honeycomb, lashing, glass beads or the like, and has a structure having a temporary foam stop function or a heat capacity and air permeability. Also good.

The second heating device 5 includes a second heater 51, a temperature sensor 52, and a temperature regulator 53. The second heater 51 is provided in the upper compartment 1a which is the upper portion of the intermediate mesh 4 of saturator 1, water to a temperature t ₂ which is the temperature for the purpose of temperature sensor 52 and the temperature controller 53.

The heating device 2 includes a heater 21, a temperature sensor 22, and a temperature controller 23. A heater 21 which is a heating portion of the heating device is provided in a lower section 1 b which is a lower portion of the intermediate mesh 4 of the saturation tank 1 and is controlled by a temperature sensor 22 and a temperature regulator 23. In this example, water can be heated to a temperature t ₃ higher than t ₂ . This t ₃ is a temperature within a range that can be restored to t ₂ by the second heater 51, and is usually set to a temperature higher than the temperature difference of about 5 ° C. from t ₂ .

The saturated air generator as described above is operated as follows and exhibits its effects.
The saturation tank 1 is filled with water, and the water level controller 16 adjusts the water level to L. When air consisting of outside air of normal humid air is sent from the air supply pipe 3 and put into the saturation tank 1 from the bottom 11, the air spreads over the entire surface by the passage resistance of the fine mesh 12, and the mesh 12 is uniformly distributed. Passes and rises as small bubbles. On the other hand, the temperature of the water in the lower section 1b of the saturation tank 1 is detected by the temperature sensor 22, and in this example, t ₂ is 50 ° C. and t ₃ = t ₂ + 3-4 ° C. = 53-54 ° C. It is heated with the heater 21 so that it may become.

In the process of ascending the small bubbles, water constantly contacts the water, and the water vapor evaporates on the bubble surface due to the difference between the water vapor pressure in the bubbles and the saturated water vapor pressure corresponding to the temperature of the surrounding water surrounding the bubbles. The temperature of the surrounding water that released the latent heat dropped, and the air in the bubbles that took in the evaporated water vapor increased in humidity, and eventually the air in the bubbles was filled with saturated water vapor at the surrounding water temperature. Becomes saturated air. As a result, water that has been heated to a t ₃ than t ₂ becomes about 1 to 2 ° C. than t ₂ higher temperatures, the air consisting of small bubbles, it becomes almost saturated air at that temperature.

The small bubbles of saturated air having a temperature higher than t ₂ ascend the lower section 1b of the saturation tank 1 and reach the intermediate mesh 4, and the corresponding portion hits the mesh of the intermediate mesh and is restricted from passing. become. That is, as shown in FIG. 2A, when the small bubble p hits the mesh line 41 of the intermediate mesh 4, it receives a support force of the mesh line and a force due to a difference in buoyancy between the upper and lower sides, and has a shape close to a circle. Although it deforms into a flat shape, the mesh 4 is temporarily caught by the mesh line 41 due to its surface tension, viscosity, etc., and this is combined with other subsequent small bubbles that rise to increase the buoyancy. Will pass. In this case, when the size of the small bubbles is larger than the size of the mesh, as shown in FIG. 4B, the rate of stable support at the four sides of the mesh line 41 is high, and when the size is small, as shown in FIG. May be supported near the intersection of the mesh 41.

  Such a phenomenon varies depending on the mesh size of the intermediate mesh, the size of the small bubbles, the depth position of the intermediate mesh, and the like, but in general, a substantial part of the bubbles once stop at the intermediate mesh 4 and pass through here. . Then, the intermediate mesh 4 is entirely covered with air bubbles, and the air bubbles are sequentially replaced and pass through the intermediate mesh. As a result, the water that has risen to convection and the water that has been lifted and conveyed by the air lift force of a large number of small bubbles cannot freely pass through the portion of the intermediate mesh 4, and eventually heated by the heater 21. The convection of water accompanying is stopped almost by the phenomenon in the lower section 1b, and only the effect of making the water temperature in the section uniform is generated. As a result, convection of water due to heating of the upper second heater 51 is also performed only in the upper section 1a. The stagnation phenomenon of small bubbles in the intermediate mesh that is the basis of such a phenomenon has been confirmed by experiments by the inventors.

Air passing through the intermediate mesh 4, since become than the temperature t ₂ 1 to 2 ° C. higher temperature saturated air, upon entering the upper compartment 1a the water temperature is in the t _2, contact with water therein temperature Te drops to t _2. As a result, the air becomes supersaturated by 1 to 2 ° C., the heat of a small amount of supersaturated water vapor moves to the water, and the water vapor condenses to become saturated steam at the target temperature t ₂ . As a result, it is possible to obtain saturated air having the desired dew point temperature with high accuracy. This saturated air is bubbled by the bubble breaking mesh 17 to remove the mist, and then is completely saturated air A ₂ and taken out from the outlet pipe 19.

In this case, it is difficult to completely saturate the water vapor in the bubble due to the difference in saturated vapor pressure by bringing the bubble into contact with water, but it is saturated by condensing the supersaturated water vapor from the supersaturated state with the water directly adhered. It is very easy to get into the state. Moreover, since the intermediate mesh 4 is formed with micropores and the air that has passed through it is made finer, the contact area with water becomes larger and the heat exchange action becomes extremely good. The inventors applied the present invention to a comparative test between a saturated gas generator provided with an intermediate mesh 4 and a conventional device without an intermediate mesh, and obtained the following results:
Set temperature t ₂ s of second heater 51 50 ° C. 80 ° C. Saturated air temperature generated t ₂ a Intermediate mesh 4 present (application of the present invention) 49.8 ° C. 79.9 ° C. No intermediate mesh 4 (conventional) 49.0 ° C. 78.8 ° C.
Therefore, saturated air having the target temperature can be obtained with high accuracy as described above. In order to condense a small amount of supersaturated water vapor in the upper compartment 1a, it is necessary to take the heat of the water in this compartment. However, when t ₂ is sufficiently higher than room temperature, for example, 50 ° C. or higher, Since there is heat radiation from the periphery of the tank 1, the amount of heat is released naturally. Thus, in this embodiment, as the heat exchange means is provided a second heater 51 is controlled to maintain the upper section 1a to t ₂ = 50 ° C. in a very small amount of heat quantity.

As described above, in the apparatus of this embodiment, the heater 2 in the lower compartment 1b of the air therein was heated from t ₂ to 3 to 4 ° C. higher by about t ₃ t ₂ from 1 to 2 ° C. of about elevated temperature almost exclusively air in the saturated air raised to upper compartment 1a, but back in the upper compartment 1 a to t ₂ so as to obtain the saturated air of accurately t _2, a t ₃ to what extent a temperature higher than t ₂ Whether it is set or not can be returned to t ₂ in the upper section 1 a, and the operating temperature or the like in the actual apparatus so that the temperature to be returned is as small as possible and there is no waste of energy consumption and the accuracy of t ₂ is improved. Determined by.

Note that when the saturated air generator is used under a t ₂ condition that is less than or equal to room temperature, a cooler is provided as the heat exchange means instead of the heater. In this case, when the apparatus is used in an environmental test apparatus having a refrigerator evaporator, the cold energy of the refrigerator can be used.

  When saturated air is continuously produced in this way, the water in the saturation tank 1 is evaporated and taken out by the saturated air, so that the water surface L of the saturation tank 1 is lowered, the water supply valve 14 is opened, and the water surface L is recovered. Water is automatically supplied into the saturation tank 1. Since this water is usually room temperature water of about 20 ° C., when the water is replenished, the inside of the tank is rapidly cooled and the temperature inside the tank is disturbed, but according to the present invention, the intermediate mesh 4 is provided and its upper and lower parts 1a, Since the second heater 5 and the heater 2 are respectively provided in 1b, convection of water is performed independently in each section as described above, and the temperature turbulence of water stops in the lower section 1b, The section 1a is hardly affected.

As a result, temporarily be made from the lower compartment 1b to the saturated air temperature supersaturated state or t ₂ following the change of the air coming up to the top section 1a, the temperature in the upper compartment 1a becomes t ₂ since it is, the air finally taken is maintained substantially entirely in the temperature t ₂ of saturated air conditions.

In the actual apparatus, the temperature of the lower section 1b is set to an appropriate value including the state at the time of water supply. In the above, an example in which t ₃ is set higher than t ₂ has been described. However, even if the temperature of the lower section 1b is set to the same temperature as t ₂ , the intermediate mesh 4 is provided and the upper and lower parts are independently heated. By combining with heating, it is possible to prevent temperature disturbance at the time of water replenishment, and to prevent deterioration in the accuracy of saturated air in the finally obtained air.

  Further, the case where the porous member is a mesh-like mesh has been described above, but the same effect can be obtained by providing a thin layer filling member such as a honeycomb, lashing, or glass beads instead of such a mesh. There is. That is, since such a member is also a porous member, it has a function of temporarily stopping small bubbles and a function of imparting resistance during passage by appropriately determining the size of the passage portion of the air, and restricting the passage thereof. Can do. Furthermore, since such a member has a constant heat capacity, when a small amount of water passes back and forth, the thermal effect of the water can be mitigated.

FIG. 3 shows another example of a saturated air generator to which the present invention is applied.
In the apparatus of this example, before the normal air A ₁ having a temperature t _{1 taken} in from the outside of the apparatus as a gas is put into the saturation tank 1, the air is supplied with a quantity of heat up to the latent heat of saturated steam at the temperature t _2. a preheating device 6 as preheating means for allowing heated to a temperature t ₄ predetermined higher t ₂ is the temperature for the purpose of. In this case, if t ₂ is about 50 ° C., t ₄ is defined as the amount of heat in the range close to the latent heat component R constituted by the latent heat component r of the saturated water vapor of the saturated air at the temperature t _{2. 1} and the normal air A ₁ is heated thereby to the elevated temperature t ₄ .

In this example, the preheating device 6 includes a preheater 61 that preheats the normal air A _1, and electric power corresponding to the latent heat component R W = RJ ----- (1)
It is comprised with the power regulator 62 etc. which can supply. J is a conversion coefficient between the amount of heat and electric power.

The power regulator 62 of the preheating device 6 is provided on the operation panel 8 so that the power supplied to the preheater 61 can be adjusted by a human operation. In addition, the apparatus of this example is provided with a control valve 7 and an operating device 71 capable of adjusting the mass flow rate G as the flow rate of the normal air A ₁ in order to produce as much saturated air as necessary. An operation device 71 is also provided on the operation panel 8.

FIG. 4 shows the configuration of the flow rates and the retained heat amounts of normal air A ₁ and saturated air A ₂ .
In the figure, g ₁ , g ₂ , h ₁ , h ₂ , hw, r, ha ₁ , ha ₂ , δh ₁ , and δha ₁ are the water vapor flow rates of A ₁ and A ₂ , the total heat amount of each water vapor, and saturation, respectively. heat of saturated water in the tank 1, the latent heat of h _2, heat of dry air of a ₁ and a _2, heat absorption amount of water vapor in a _1, and an endothermic quantity of dry air.

As shown in the figure, normal air A ₁ having a flow rate G including a water vapor flow rate g ₁ and a dry air flow rate (G-g ₁ ) is added to the flow rate g ₂ in the saturation tank 1 to obtain a flow rate (G + g ₂ ). It becomes saturated air a _2. The heat, A _1, This temperature t _2, with the water vapor flow rate g ₂ is added, the temperature was raised from t ₁ to t _2, it becomes increased A ₂ of heat only Q _1.

The amount of heat Q ₁ is
Q ₁ = g ₂ r + g ₂ hw + g ₁ δh ₁ + (G−g ₁ ) δha ₁ −− (2)
It is. Among _{g 2 r = R ---- (3} )
Corresponds to the latent heat component R and occupies most of Q ₁ as will be described later. In this example, as described above, the heat amount of R = g ₂ r can be supplied to the normal air A ₁ by the preheating device 6.

In order to obtain R = g ₂ r, g ₁ and g ₂ are obtained from G and a wet air diagram, and r is obtained from a saturated steam table or a diagram. For g ₁ and g ₂ , if the absolute humidity of the air of A ₁ and A ₂ is x ₁ and x ₂ , respectively,
g ₁ = x ₁ (G−g ₁ )
g ₁ + g ₂ = x ₂ (G−g ₁ )
From these formulas,
_{g 2 = G (x 2 -x} 1) / (1 + x 1) ---- (4)
Is obtained.

In this case, if the normal air A ₁ is normal outside air having a temperature of about 20 ° C. and a relative humidity of about 50%, for example, if the x ₁ is sufficiently small with respect to x ₂ , this is omitted or simplified.
g ₂ ≒ Gx ₂ ----- (5)
g ₂ ≒ KGx ₂ ---- (5) '
Can be easily obtained. K is set to about 0.9. In this case, R≈Grx ₂ or R≈KGrx ₂ is the amount of heat within a range close to the latent heat component R.

As described above, the power W corresponding to the latent heat R supplied to the normal air A ₁ by the power regulator 62 is
W = RJ = GrJ (x ₂ −x ₁ ) / (1 + x ₁ ) −−− (6)
Or
W ≒ Gx ₂ rJ or _{W ≒ KGx 2 rJ --- (7} )
Can be determined as Here, G is understood from the scale when operating the operation device 71, and r and x ₂ are the temperature t ₂ of the saturated air A ₂ and the set temperature t of the temperature controller 53 that controls the second heater 51. Obtained from ₂ . Further, x ₁ is usually obtained by measuring the temperature t ₁ and the relative humidity ψ ₁ of the air A ₁ or directly measuring the absolute humidity x ₁ .

In this case, in actual use of the saturated air generator, a table or a carp in which W is obtained using G, t ₂ , or t ₁ and ψ ₁ or x ₁ as parameters, if necessary, is prepared in advance. W is determined by looking at them, and the power regulator 62 is operated according to the calculated W. It is also possible to provide a control device and detectors such as G, t ₁ , t _2, etc., calculate W from the detected data, and automatically operate so that the output of the power regulator 62 becomes the calculated W. .

The preheater-related part of the saturated air generator provided with the preheater 6 as described above is operated as follows and exhibits its effects.
The adjustment valve 7 for adjusting the air flow rate of the air supply pipe 3 is adjusted by an operating device 71 provided on the operation panel 8 so as to flow, for example, humid air of G = 50 g / min as a target flow rate. The As this air, for example, normal air A _{1 which} is a raw material having a temperature t ₁ = 20 ° C. and a relative humidity ψ ₁ = 50% is supplied, and the power regulator 62 of the preheating device 6 supplies power W to the preheater 61. A ₁ receives the supply of latent heat R and is heated. At this time, W is set to a value calculated by the equation (6) including x ₁ from the above t ₂ = 50 ° C. and G = 50 g / min or a value estimated by the equation (7).

This W is given in the table as described above, and when this is calculated from an example of the conditions such as G, t ₁ , t ₂ etc., G = 50 g / min = 3 kg / hr, x ₂ = 0. 0.086 kg / kgDA, r = 2383 KJ / kg, x ₁ = 0.008 kg / kgDA, from equation (6), R = 553.3 KJ / h, W = 153 w, from equation (7), R = 614.8 KJ / H, W = 170w or R = 0.9 × 614.8 = 553.3 KJ / h, W = 0.9 × 170 = 153 w.

If the preheater 61 power adjustment as such power is supplied normally air A ₁ passes, and latent heat R is given by the above power W to A ₁ A ₁ is raised, the The temperature-up air A ₄ has a predetermined temperature t ₄ . At this time t ₄ is
t ₄ = (R / GCp) + t ₁ −−−− (8)
Is calculated by Cp is the average constant pressure specific heat of air in the temperature raising process, and is about 1 J / g · ° C. Therefore, from R, G, and t ₁ , t ₄ becomes t ₄ = 204 ° C. or 225 ° C. or 204 ° C. according to the equation (6) or (7).

When the heated air A ₄ heated to the sufficiently high temperature t ₄ is discharged from the bottom 11 of the saturation tank 1 into the water whose temperature is adjusted to t ₃ = 51 to 52 ° C. in this example, the temperature t 4 _While the air of ₄ is brought into contact with water to evaporate a part thereof and take in as water vapor, it rises due to the difference in specific gravity with water, is divided into small bubbles by the fine mesh 12, and further heat exchanges with water to evaporate the water. Surface. However, since the heated air A ₄ is only given the amount of heat of the latent heat component R, the amount of heat other than R = g ₂ r in the equation (2) is taken from the heater 21 through water, Finally, it becomes small bubbles of saturated air at 51 to 52 ° C., passes through the intermediate mesh 4 and enters the upper section 1a, and is processed in the same manner as the apparatus of FIG.

In such a process of generating saturated air, since the temperature rising air A ₄ is at a temperature at which the latent heat component R is retained, the water in the lower section 1 b of the saturation tank 1 is necessary to evaporate a part thereof. Without losing a large amount of heat, which is a latent heat component, it is only necessary to give the normal air A ₁ only the sensible heat for raising the temperature of the normal air A ₁ at a temperature of 20 ° C. to a temperature of 51 to 52 ° C. Therefore, the temperature controllability of the lower section 1b is improved, and eventually the temperature controllability in the upper section 1a can be further improved.

Further, since the temperature rising air A ₄ is put into the saturation tank 1, the high temperature air comes into contact with the water to easily evaporate the water, and the introduced air quickly reaches the state close to the saturated air. be able to.

FIG. 5 schematically shows changes in temperature and humidity in the saturation tank of the introduced air as described above. In the figure, the solid line shows the case where the present invention is applied to supply the heat quantity up to the latent heat to the introduced air and preheated to a temperature sufficiently higher than the saturation temperature t ₂ , and the two-dot chain line is the structure shown in FIG. The case where the introduced air is preheated to the saturation temperature t ₂ as in the prior art using the saturation tank 1 having the same dimensions as shown in FIG.

As shown in the figure, when the present invention is applied, since there is a considerable temperature difference between the introduction air temperature and the saturation temperature t ₂ , the effect of directly heating and evaporating water in addition to the partial pressure difference occurs as described above. Since the saturation of the introduction air rises quickly, it finally reaches the saturation air of 100% saturation at the outlet of the saturation tank 1, but when the conventional technology is applied, even if heating to the introduction air is not necessary, Since the water vapor is supplied only by the partial pressure difference, the humidity rises slowly, and the saturation level of the small size of the saturated tank as shown in FIG. 1 does not finally reach 100%.

Also, since the introduced air evaporates water and raises the degree of saturation, the portion of the water that supplies the latent heat of vaporization around the bubbles of the introduced air lowers the temperature and supplies water vapor, so the introduced air is also saturated. Although the temperature drops slightly from the temperature t ₂ , when the present invention is applied, the temperature drop amount is very small and the time when the temperature drops is delayed.

FIG. 6 shows another example of a saturated air generator to which the present invention is applied.
In the apparatus of this example, the preheating device 6 which is preheating means is the preheater 61 for preheating the gas, and the operating device for operating the mass flow rate adjusting valve 7 in this example as the flow rate output means for outputting the gas flow rate G. 71 and its flow rate output unit 72, the flow rate G output from this output unit 72 and the target temperature t ₂ are taken in, and the latent heat component R, which is the amount of heat, is calculated from the conditions including G and t _2. calculator 63 as an ordinary calculation means for calculating the temperature t ₄ after preheating of the air a ₁ is a temperature sensor 64 for detecting the temperature t _4, the detected temperature t ₄ p detected by the temperature sensor 64 is calculated 63 the power regulator 62 of the power setting section 62a as a control means for controlling the power W of the calculated amount of heat the preheater 61 so that after the preheating the temperature set temperature t ₄ s after preheating, is constituted by such ing.

The operation device 71 gives an opening degree signal to the control valve 7 and determines the air flow rate passing through the control valve 7 in response to the signal. The flow rate output unit 72 incorporated therein outputs the corresponding air flow rate to the calculation unit 63 by this opening degree signal. The target temperature t ₂ of the saturated air to be generated is normally set here by providing the setting unit 81 in the operation panel 8 as a changeable set temperature, so the temperature t _{2 taken} into the calculation unit 63 is It is transmitted from the setting unit 81.

The calculation unit 63 calculates R and t ₄ from the condition including G and t _2, and this calculation is performed by the method described so far. In this case, R may be calculated by equation (6) or (7) using only x ₂ obtained from G and t ₂ . In addition, since the temperature and humidity conditions of the normal air A ₁ usually do not greatly affect the calculation of R and t ₄ , for example, as described above, the calculation unit assumes a constant value such as a temperature of 20 ° C. and a relative humidity of 50%. 63 may be input in advance, and the condition of A ₁ may be added to G and t ₂ , R may be calculated using equation (6), and t ₄ may be calculated using equation (8). Further, since t ₁ and ψ are usually measured, the measured values may be input. The calculation unit 63 is configured to hold a necessary data portion of a saturated steam table and a wet air diagram for performing such calculation.

According to the saturated air generating apparatus of FIG. 6 as described above, the amount of latent heat can be automatically supplied. Therefore, compared with the apparatus of FIG. 3, the operation operation is facilitated and labor saving can be achieved. Further, since the temperature of the temperature raising air A ₄ is controlled, it is possible to prevent an abnormal temperature rise. Note that the calculation unit 63 may calculate R to electric power W and supply or control the electric power as described above. Even in this case, the driving operation can be facilitated.

FIG. 7 shows a change state of the absolute humidity x ₂ with respect to the temperature of the saturated air.
As shown in the figure, when the temperature of the saturated air exceeds about 50 ° C. to 60 ° C., x ₂ rapidly increases. And, as shown in the previous equations (5), (5) ′, (7), x ₂ has a value corresponding to the latent heat component R. Therefore, when the saturation temperature is exceeded, the value of R becomes too large. When the air is preheated with R, the temperature t _{3 of the} heated air becomes abnormally high. For example, when t ₂ becomes 80 ° C., t ₃ exceeds 1000 ° C., and the preheater 31 becomes large, or the temperature of the air entering the saturation tank 1 becomes high, resulting in poor handling of the apparatus. .

Therefore, in a saturated air generator that may be used under conditions where the saturation temperature t ₂ exceeds about 60 ° C., the air is preheated with a heat quantity equal to or less than the latent heat component R. That is, for example, when the maximum capacity of the preheater 31 can be exchanged up to R when t ₂ is 60 ° C., and when the saturated air A ₂ having t ₂ of 80 ° C. is produced, the normal air A ₁ is preheated with the maximum preheating capacity of the preheater 31.

However, even when the normal air A ₁ is preheated with a heat quantity of R or less in this way, in the saturation tank 1, the latent heat burden ratio of water is reduced, and the heat exchange in the heater 2 is made with a negative sensible heat load. It is possible to reduce the size of the saturation tank 1 by shortening the heat exchange distance of the saturation tank 1 while improving the performance and greatly promoting the evaporation of water as compared with the conventional apparatus, making the heater 2 small. . For example, even when the saturation temperature t ₂ is about 50 ° C., the latent heat component R is a temperature at which the effect of reducing the latent heat load and making the sensible heat load negative is obtained as a predetermined temperature higher than t _2. It is possible to preheat the air A ₁ to an intermediate temperature t ₃ ′ of about 100 ° C. to 150 ° C., although it is lower than t ₃ when heated at. Even in such a case, it is possible to obtain saturated air that is smaller than conventional devices and has high dew point accuracy.

  In the above, the case where the saturated gas generator generates saturated air has been described. However, the present invention can convert an inert gas such as nitrogen or another gas into a saturated gas containing saturated water vapor as necessary. can do.

  The present invention relates to a technique for generating saturated air having an accurate dew point temperature. In particular, the present invention is used for humidity sensor calibration and the like, and realizes a precise humidity condition by a shunt method, a two-temperature method, a two-pressure method, or a two-temperature two-pressure method. It is advantageously used as a precision humidity generator, and as a humidifier for fuel gas and oxidant gas used in fuel cell drive devices and test devices.

It is explanatory drawing which shows an example of the whole structure of the saturated air generator to which this invention is applied. (A) thru | or (c) is explanatory drawing which illustrated the state of the bubble in the intermediate | middle mesh part of the said apparatus. It is explanatory drawing which shows the other example of the saturated air generator to which this invention is applied. It is explanatory drawing which shows the flow of normal air and saturated air, and the state of retained heat. (A) And (b) is a curve figure which shows the change state of the temperature and humidity of introduction air. It is explanatory drawing which shows the further another example of the saturated air generator to which this invention is applied. It is a curve figure which shows the relationship between the temperature of saturated air, and absolute humidity.

Explanation of symbols

1 Saturation tank (container)
1a Upper section (upper part)
1b Lower section (lower part)
2 Heating device (heating means)
4 Intermediate mesh (porous member)
5 Second heating device (heat exchange means)
6 Preheating device (preheating means)
21 Heater (heating means)
51 Second heater (heat exchange means)
61 Preheater (Preheating means)
Z Vertical direction L ₁ Intermediate position

Claims (3)

The water contained in the container is heated by a heating means, and a gas is put into the container to disperse the gas in the water, and the gas is brought into contact with the water to make the gas a saturated steam-containing gas at a target temperature. In the saturated gas generator adapted to be removed from the container,
A porous member provided to restrict the passage of the gas at an intermediate position in the vertical direction of the container, and the gas is set to the target temperature in an upper portion of the porous member of the container. A saturated gas generator, wherein the heating means is provided in a lower portion of the porous member of the container.   The said heating means can heat the said gas to a temperature that is higher than the target temperature and that can be restored to the target temperature by the heat exchanging means. Saturated gas generator. Before the gas is put into the container, preheating means is provided to supply the gas with an amount of heat up to the latent heat of the saturated water vapor so that the gas can be heated to a temperature higher than the target temperature. The saturated gas generator according to claim 1 or 2.

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