JP2003181201A - Operation method of distillation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation method of a distillation apparatus to keep the purity of a distillate by optimally supplying a liquid to be distilled. <P>SOLUTION: The operation method of the distillation apparatus 1 that is provided with an evaporation chamber 2 for the liquid to be distilled, a heating means 3 for heating the liquid to be distilled in the evaporation chamber 2 and a condenser 4 for condensing the evaporated vapor, includes a process of supplying the liquid to be distilled until the heating means 3 is submerged under the liquid to a prescribed depth in the evaporation chamber 2 in a state that the operation of the heating means 3 is stopped, a process of operating the heating means 3 in a state that the heating means is completely submerged under the liquid, and a process of supplying the rated quantity of the liquid to be distilled after the signal to start the supply of the liquid to be distilled is detected during the operation of the heating means 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a distillation apparatus for distilling water, a solvent and the like, and more particularly to controlling the supply amount of a liquid to be distilled.

[0002]

2. Description of the Related Art In recent years, from the viewpoint of environmental problems, in the treatment of waste water and waste liquid, a treatment by distillation has come to be performed.
That is, the waste liquid, which is the liquid to be distilled, such as cleaning water and cleaning solvent, is evaporated by a heating means, and the evaporated vapor is cooled to be distilled to reduce the volume of the waste liquid and recover and reuse the distilled liquid. Came to do. When the liquid to be distilled contains a detergent or the like, in the evaporation chamber of the distillation apparatus,
Bubbles may occur. Due to the generation of bubbles, the detergent component is mixed in the distillate and the purity of the distillate is lowered. In order to improve the purity of the distillate, it is necessary to lower the liquid level of the liquid to be distilled in the evaporation chamber. That is, in the evaporation chamber, it is necessary to lower the liquid level to form a space, and the vapor containing no bubbles should be accumulated in the space. On the other hand, if the liquid level is lowered too much, the heating means may become empty.

[0003]

The problem to be solved by the present invention is to provide an operation method for supplying the liquid to be distilled optimally and maintaining the purity of the distillate.

[0004]

The present invention has been made in order to solve the above-mentioned problems. The invention according to claim 1 provides an evaporation chamber for a liquid to be distilled and a liquid to be distilled in the evaporation chamber. A method for operating a distillation apparatus comprising heating means for heating and a condenser for condensing evaporated vapor, wherein the heating means is kept in a predetermined depth in the evaporation chamber in a state where the operation of the heating means is stopped. A step of supplying a liquid to be distilled until submerged, a step of operating the heating means in the submerged state,
After the operation of the heating means, after the time point when the supply start signal of the liquid to be distilled is detected, the step of supplying the liquid to be distilled at a rated value is included.

The invention described in claim 2 is characterized in that the supply start signal of the liquid to be distilled is detected based on the average value of the apparent liquid level of the liquid to be distilled in the evaporation chamber.

Further, the invention according to claim 3 is that the detection of the average value is executed based on the detection value at a portion not directly heated by the heating means and at a lower level than the heating means. It has a feature.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. The present invention is preferably implemented in a method of operating a distillation apparatus. A configuration of a distillation apparatus suitable for applying the present invention will be described.

The distillation apparatus includes an evaporation chamber for evaporating a liquid to be distilled, a heating means for heating the liquid to be distilled in the evaporation chamber, a condenser for condensing evaporated vapor, and a supply of the liquid to be distilled into the evaporation chamber. It is configured by a supply means for performing, a liquid level detection means in the evaporation chamber, and a controller for outputting a command for operating and stopping the supply means and controlling the distillation apparatus.

The distilling device distills waste liquid as a liquid to be distilled in the evaporation chamber by the heating means and cools the evaporated vapor by the condenser to distill it.
The volume of the waste liquid is reduced and the distillate is recovered and reused. In such a distillation apparatus, an embodiment of a method for operating the distillation apparatus according to the present invention will be described.

First, the supply amount of the liquid to be distilled which can be distilled according to the amount of heat of heating by the heating means is previously determined as the rated supply amount. Here, the rated supply amount is a supply amount in which the supply amount per unit time balances with the heating heat amount, and it is preferable that the rated supply amount is continuously supplied. However, depending on the implementation, the rated supply amount is intermittently supplied. You can also Then, in a state where the operation of the heating means is stopped, the operation of the supply means is stopped after the operation of the supply means until the heating means is submerged in the liquid to be distilled to a predetermined depth in the evaporation chamber. To do. Next, with the operation of the supply means stopped, the heating means is operated in the liquid submerged state to evaporate and distill the liquid to be distilled. By performing this distillation after the operation of the heating means, the liquid level in the evaporation chamber is lowered, and when a signal at the time when the supply of the liquid to be distilled is started is detected, the heating means is operated after this time. While the distillation is being performed, an operation of supplying the liquid to be distilled having the predetermined supply amount determined in advance is performed.

When the liquid to be distilled is heated by the heating means in the evaporation chamber, the surface temperature of the heating means is higher than the saturation temperature of the steam, and thus a large number of small bubbles are generated on the surface of the heating means. Then, a large number of these small bubbles aggregate to grow into a large bubble. Here, if impurities such as a detergent or a surfactant are present in the liquid to be distilled, the growth of bubbles is promoted, and a large number of bubbles are formed so as to rise from the liquid surface and are formed in the evaporation chamber. Therefore,
The liquid level in the evaporation chamber is apparently raised. Further, the bubbles constantly repeat defoaming and foaming, so the apparent liquid level fluctuates. Therefore, the supply start signal of the liquid to be distilled is detected based on the average value of the apparent liquid level of the liquid to be distilled in the evaporation chamber.

The suitable detection of the average value is carried out based on the detection value at a portion not directly heated by the heating means and at a level lower than that of the heating means. For example, a liquid level detecting pipe that connects the upper part and the lower part of the evaporation chamber is provided, and in this liquid level detecting pipe, the liquid level detecting means is provided at a lower level than the heating means. Then, the liquid level detecting means obtains an average value. That is, since the liquid level detection pipe is not heated, no bubbles are generated inside it, and the liquid level detection pipe has an average liquid level corresponding to the liquid head pressure of the liquid to be distilled in the evaporation chamber. Therefore, the average value can be obtained by detecting the average liquid level by the liquid level detecting means.

At this time, the liquid level detecting means is provided at a level lower than that of the heating means, but the liquid level in the evaporation chamber rises due to the generated bubbles, and the heating means has an apparent liquid level. Since it is submerged in the liquid, it will not be empty.

Further, as the concentration of the liquid to be distilled in the evaporation chamber progresses, foaming increases and bubbles of the liquid to be distilled become droplets and are mixed in the liquid to be distilled. Then, in addition to the evaporated amount of the liquid to be distilled that has been rated and supplied, the amount mixed in the distilled liquid also disappears from the evaporation chamber. Therefore, both the decrease in the liquid level due to evaporation and the decrease in the liquid level due to mixing in the distillate liquid exceed the increase in the liquid level due to the rated supply.
The balance between the disappearance and the supply is lost, and the liquid level in the evaporation chamber is lowered. When the liquid level decreases, the rise of bubbles also decreases, so that the mixture of the liquid to be distilled into the distilling liquid also decreases, and the purity of the distilling liquid gradually recovers. Therefore, a highly pure distillate can be continuously obtained, and can be recovered and reused. In the evaporation chamber, the concentrated liquid to be distilled can be taken out as a reduced volume.

Here, it is preferable to detect the supply start signal of the liquid to be distilled by detecting the average value, but depending on the execution, it is performed after a predetermined time has elapsed from the start of the operation of the heating means. You can also

Further, the heating means is provided with a temperature detecting means, and when the temperature detected by the temperature detecting means exceeds a specified value, it is judged that the inside of the evaporation chamber is in a low liquid level state, and the supply means of the supplying means is operated. It is also suitable to continue the operation and issue an alarm depending on the implementation. In this case, the temperature of the heating means may exceed a specified value due to the adhesion of foreign matter such as scale to the heating means. At this time, it can be notified that an abnormality has occurred in the heating means. As a result, the distillation apparatus can be operated more safely.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described in detail below with reference to FIG. FIG. 1 is a schematic explanatory view of a distillation apparatus suitable for carrying out the present invention. Here, the drainage that is the liquid to be distilled will be described by taking cleaning drainage as an example.

In FIG. 1, a distillation apparatus 1 for distilling cleaning wastewater comprises an evaporation chamber 2 for storing cleaning wastewater, and an evaporation chamber 2 for this.
A heater 3 as a heating means for heating the cleaning waste water inside,
A condenser 4 for condensing evaporated vapor, a water supply pump 5 for supplying cleaning waste water into the evaporation chamber 2, a float switch 6 for determining an upper limit water level in the evaporation chamber 2 at startup, and the evaporation chamber 2 It is composed of a water level detecting means 7 for detecting the average water level in the inside, and a controller 8 for outputting a command for operating and stopping the water supply pump 5 and controlling the distillation apparatus 1.

The distillation apparatus 1 is connected to a cleaning tank 10 for cleaning an object to be cleaned (not shown) via a distilled water pipe 9 for supplying distilled distilled water. The distillation apparatus 1 is connected to a drainage tank 11 that stores cleaning drainage from the cleaning tank 10 via a water supply pipe 12.

The bottom of the evaporation chamber 2 is connected to the water supply pipe 12, and the water supply pipe 12 is connected to the water supply pump 5 and a check valve 13 as a backflow preventing means.
Is provided. The evaporation chamber 2 is provided with a steam pipe 14 communicating with the condenser 4 on the upper part thereof.
Further, the evaporation chamber 2 is provided with a blow pipe 15 for draining the concentrated cleaning waste water at the bottom thereof. The evaporation chamber 2 includes the float switch 6 inside the evaporation chamber 2, and further includes a water level detection pipe 16 that connects the upper portion and the lower portion of the evaporation chamber 2 to each other.
Is provided with the water level detecting means 7.

The heater 3 penetrates the lower side surface of the evaporation chamber 2 and is inserted into the evaporation chamber 2. A portion of the heater 3 inside the evaporation chamber 2 is a heat generating portion 17 having a built-in electric heating coil, and an outer portion of the heater 3 outside the evaporation chamber 2 is a power source portion 18. A temperature sensor 19 for detecting the temperature of the heat generating portion 17 is provided on the top of the heat generating portion 17.
Is provided.

The condenser 4 cools and condenses the steam introduced from the steam pipe 14, and is connected so as to supply distilled water to the bottom of the cleaning tank 10 through the distilled water pipe 9. Has been done. Here, the distilled water pipe 9 is provided with an atmosphere open end portion 20 that makes the pressure in the condenser 4 atmospheric pressure and also releases the atmosphere in the distilled water pipe 9 to the atmosphere. This open end 20
Is installed at a height at which a water head pressure higher than the surface of the cleaning water in the cleaning tank 10 can be obtained. Distilled water is supplied to the bottom of the cleaning tank 10 at this water head pressure, and the inside of the cleaning tank 10 is cleaned. Prevent backflow of water. The cleaning tank 10 is connected to the drain tank 11 via an overflow pipe 21.

The float switch 6 is provided in the evaporation chamber 2 when the distillation apparatus 1 is started up.
It is configured to determine the upper limit water level for submersing the water in the cleaning wastewater. That is, when the distillation apparatus 1 is started up, it is detected whether or not the water surface of the cleaning wastewater in the evaporation chamber 2 has reached the float switch 6, and when it is detected that the arrival signal is sent to the float switch 6. Output to the controller 8.

The water level detecting means 7 is configured to detect the water level in the water level detecting pipe 16 at a level lower than the top of the heat generating portion 17. That is, when the water level in the water level detection pipe 16 is lowered to a level lower than the level of the top of the heat generating part 17, a cleaning drain supply start signal is output to the controller 8.

The controller 8 is connected to the water supply pump 5, the float switch 6, the water level detecting means 7, the power source section 18 and the temperature sensor 19 through lines (reference numerals are omitted). Depending on the implementation, it is also suitable to connect to the capacitor 4 via a line (not shown).

Here, the distillation apparatus 1 having the above structure
The action of will be described. The distillation apparatus 1 evaporates the cleaning waste water in the evaporation chamber 2 by the heater 3 and distills the evaporated steam by cooling it in the condenser 4 to reduce the volume of the cleaning waste water and recover the distilled water. It is for reuse. That is, the cleaning drainage stored in the drainage tank 11 is supplied into the evaporation chamber 2 by the water supply pump 5, the cleaning drainage is heated by the heater 3 to form steam, and the steam is introduced into the condenser 4. To cool. Then, the distilled water of the cooled cleaning waste water is collected and reused as cleaning water in the cleaning tank 10. Also,
In the evaporation chamber 2, the concentrated cleaning waste water is regarded as having a reduced volume, and the drain valve 2 of the blow pipe 15 is used.
Open 2 and take it out.

Now, a method of operating the distillation apparatus 1 will be described with reference to FIG. First, the supply amount of the cleaning waste water that can be distilled according to the amount of heat generated by the heater 3 is previously determined as the rated supply amount, and the determined value is input to the controller 8.

Next, according to a command from the controller 8,
By operating the water supply pump 5 for cleaning drainage,
It is supplied into the evaporation chamber 2 through the water supply pipe 12. At this time, the heating portion 17 is submerged in the cleaning wastewater to a predetermined depth so that the cleaning wastewater can be heated by the heater 3 at the time of startup. That is, until the float switch 6 detects the upper limit water level, the water supply pump 5 is connected to the controller 8
To supply the cleaning drainage into the evaporation chamber 2.

When the float switch 6 detects the upper limit water level, the operation of the water supply pump 5 is stopped, and the heater 3 is operated with the operation of the water supply pump 5 stopped.
That is, from the power supply unit 18 to the heat generating unit 1
Power is supplied to 7 to heat and evaporate the washing waste water.

When the cleaning wastewater is heated by the heater 3 in the evaporation chamber 2, since the surface temperature of the heat generating portion 17 is higher than the saturation temperature of the steam, many small bubbles are generated in the heat generating portion 1.
It occurs on the surface of No. 7. Then, a large number of these small bubbles aggregate to grow into a large bubble. Here, if impurities such as a detergent and a surfactant are present in the cleaning waste water, a large number of bubbles are formed so as to rise further from the water surface and are formed in the evaporation chamber 2. Therefore, the evaporation chamber 2
The water level inside is apparently rising.
Moreover, the apparent water level fluctuates because the foam constantly repeats defoaming and foaming.

By continuing this distillation operation after the heater 3 is operated, the water level in the evaporation chamber 2 is lowered, and this drop progresses to a level lower than the top level of the heat generating section 17. When the water level detecting means 7 detects the signal, that is, when a signal at the time of starting the supply of the cleaning drainage is detected, after this time, the controller 8 operates the water supply pump 5 while continuing the operation of the heater 3. Then, the cleaning wastewater having the predetermined supply amount determined in advance is supplied to the evaporation chamber 2
Control to supply inward.

Here, the signal for starting the supply of the cleaning drainage is detected based on the average value of the apparent water level of the cleaning drainage in the evaporation chamber 2. The average value is detected by the water level detecting means 7. That is, the detection of the water level in the water level detection pipe 16 performed by the water level detection means 7 detects the water level in the water level detection pipe 16 as a water head pressure, and when the water head pressure becomes equal to or lower than a predetermined water head pressure, the control is performed. This is performed by determining that the water level has dropped by the vessel 8. Since the water level detection pipe 16 is not heated, no bubbles are generated inside the water level detection pipe 16, and the average water level of the cleaning drainage in the evaporation chamber 2 is
It is detected as corresponding to the water head pressure in the water level detection pipe 16. By detecting this average water level with the water head pressure by the water level detecting means 7, the average value of the water level can be obtained.

Here, in the method of detecting the water level in the water level detecting pipe 16, it is preferable to detect the water level in the water level detecting pipe 16 as a head pressure. Using a rod (not shown), the detection end of this water level detection electrode rod is set to a level lower than the level of the top of the heat-generating part 17, and it is detected that there is no electrical continuity between the detection end and the water surface. It is also preferable to determine that the has decreased.

At this time, the water level detecting means 7 is provided at a level lower than that of the heat generating portion 17, but the water level in the evaporation chamber 2 rises due to the generated bubbles,
Since the heat generating portion 17 is submerged in the apparent water level,
It will not be fired.

When the heater 3 is operated to perform the distillation work and the distillation work for supplying the cleaning wastewater of the rated supply amount into the evaporation chamber 2 is further continued, the cleaning wastewater in the evaporation chamber 2 is removed. Concentration proceeds. Then, foaming increases in the evaporation chamber, and the bubbles of the cleaning waste water become droplets and mix into the distilled water. In that case, in addition to the evaporated amount of the cleaning drainage supplied at the rated amount, the amount mixed in the distilled water also disappears from the evaporation chamber 2. Therefore, both the decrease in the water level due to evaporation and the decrease in the water level due to mixing with distilled water exceed the increase in the water level due to the rated supply, and the balance between the disappearance and the supply is disrupted. The water level drops.

When the water level lowers, the rise of bubbles also lowers, so that the mixing of the cleaning waste water into the distilled water also decreases, and the purity of the distilled water gradually recovers. Therefore, distilled water with high purity can be continuously obtained,
It can be collected and reused as wash water.

Next, when the distillation work for a predetermined amount or for a predetermined time is completed, it is assumed that the concentrated cleaning waste water in the evaporation chamber 2 has been reduced in volume and the blow pipe 1
The drain valve 22 is opened from 5 and taken out to the outside.
Then, the drain valve 22 is closed and the process proceeds to the next distillation operation.

On the other hand, when the temperature of the heat generating portion 17 detected by the temperature sensor 19 exceeds a specified value, the controller 8 determines that the inside of the evaporation chamber 2 is in a low water level, and the float switch. The operation of the water supply pump 5 is continued and an alarm is issued until 6 detects the water level.

In this case, the temperature detected by the temperature sensor 19 may exceed a specified value due to the attachment of foreign matter such as scale to the heat generating portion 17. At this time, the float switch 6 detects the water level. If so, the controller 8 can determine and inform that the scale adhesion abnormality of the heater 3 has occurred. As a result, the distillation apparatus 1 can be operated more safely.

[0040]

According to the present invention, it is possible to optimally supply the liquid to be distilled and perform the operation of maintaining the purity of the distillate.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a distillation apparatus suitable for applying the present invention.

[Explanation of symbols]

1 distillation equipment 2 evaporation chamber 3 heater (heating means) 4 capacitors

Claims (3)

[Claims] 1. A method of operating a distillation apparatus 1 comprising: an evaporation chamber 2 for a liquid to be distilled; a heating means 3 for heating the liquid to be distilled in the evaporation chamber 2; and a condenser 4 for condensing evaporated vapor. There is a step of supplying the liquid to be distilled until the heating means 3 is submerged to a predetermined depth in the evaporation chamber 2 in a state where the operation of the heating means 3 is stopped, and A distillation apparatus comprising: a step of operating the heating means 3; and a step of, after the operation of the heating means 3 and after detecting a supply start signal of the liquid to be distilled, a rated supply of the liquid to be distilled. how to drive. 2. The distillation apparatus according to claim 1, wherein the supply start signal of the liquid to be distilled is detected based on the average value of the apparent liquid level of the liquid to be distilled in the evaporation chamber 2. how to drive. 3. The method according to claim 2, wherein the detection of the average value is performed based on a detection value at a portion not directly heated by the heating means 3 and at a level lower than that of the heating means 3. A method for operating the described distillation apparatus.