JP2005131543A - Apparatus for regeneration of used cleaning solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for distilling a contaminated used cleaning solution used in cleaning of blankets for offset printing processes and maintenance of printing machines so as to permit reuse of the solution. <P>SOLUTION: This apparatus has a cylindrical evaporating chamber 2, a flocculating chamber 5 having a cyclone function in its lower part, a mist-generating chamber 1 having an element 12 generating ultrasonic waves, a pipe conduit 7 forming a gas-circulating passage passing from the chamber 2 through the chamber 5 to the chamber 1, a blower 3 generating a circulation flow between the chambers 2 and 5 or between the chambers 5 and 1 and heat exchangers 4 and 6 respectively in the parts of the conduit 7 between the chambers 2 and 5 and between the chambers 5 and 1, and the exchangers 4 and 6 are connected by a heat-transferring means. The heat of a circulating gas is absorbed by the exchangers 4 and 6 arranged between the chambers 2 and 5, transferred to the exchangers 4 and 6 arranged between the chambers 5 and 1 by the heat-transferring means and dissipated into the circulating gas. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for distilling a dirty cleaning liquid used for cleaning a blanket in an offset printing process and maintaining a printing press and enabling reuse.

  For the blanket cleaning of an offset printing machine, a type in which a solvent that improves permeability is added to a petroleum-based solvent (such as kerosene) is generally used. As a conventional apparatus for reusing such a solvent, a combination of a precipitation tank and a filter is used. This method cannot remove the soluble components contained in the ink remaining on the blanket. Since the cleaning effect is reduced by one or two reuses, the new solution 1 is mixed with the regenerated solution 2 and used at present. On the other hand, many cleaning liquids are used in the manufacturing process of electronic parts, but many cleaning liquids for cleaning electronic parts are highly permeable and harmful to humans. Distillation is used in equipment that recycles solvents that are harmful to human bodies, such as electronic component cleaners. However, the distillation equipment is large and expensive, and it is also necessary to manage the exhaust and to cool the equipment by heat generation. It is not used in the printing field for reasons such as increased load. As a result of recent technological progress, low-cost cleaning solvents that are less harmful to the human body are used in various fields. These solvents are used in small amounts, but the total amount is large on a global scale, and it is harmful to humans.

Conventional distillation apparatuses are roughly classified into (1) boiling distillation apparatus, (2) vacuum distillation apparatus, and (3) reflux distillation apparatus. The boiling distillation apparatus of (1) is a type in which a liquid is put in a kettle and heated to a boiling state, and the generated vapor is led to a condenser and cooled to return to a liquid. Heating to the temperature for boiling is necessary to continue to give the heat of vaporization necessary to generate steam, and in the condenser, heat that is approximately equal to the heat absorbed by heating is absorbed. Since it releases, it is necessary to remove the same amount as the heated heat. In addition, more heat is used for heat dissipation and the amount of heat dissipated by the hook and the efficiency of cooling the condenser, and so heat is consumed. Furthermore, when used in a cooled factory or the like, the electric power necessary for cooling increases as a cooling load, so that it is not suitable for continuous recycling of the solvent in the vicinity of the cleaning device. In the vacuum distillation apparatus (2), the amount of heat for heating or condensing can be reduced by reducing the boiling point of the liquid by lowering the container, but the evaporation chamber is added to the decompression container and the condensing side. The equipment becomes expensive, such as a pressure vessel and a pump for decompression and pressurization, and the cost is not suitable for the purpose of recycling the waste liquid from the cleaning in the printing shop. In addition, as a common disadvantage of both, cleaning solvents with components with greatly different boiling points and vapor pressures have different component ratios before and after distillation, which can be reused for many cleaning agents. Not fit for purpose. In general, the reflux type distillation apparatus of (3), which is generally used for industrial purposes, uses water vapor as a dry distillation gas, but a boiler for generating water vapor is required separately from the distillation apparatus. Also, the dry distillation method using water vapor is not suitable as a recycling apparatus because a cleaning solvent to which a component that is easily soluble in water such as alcohol is added changes the component ratio after distillation. In the laboratory, nitrogen dry distillation equipment such as ether recovery may be used, but it is assembled for each target solvent, and there is nothing that can be applied to the recycling of various cleaning solvents. In addition, industrially used solvent production plants are designed to work efficiently only with specific solvents, but they are not adaptable as detergent distillation regenerators for solvents containing various additives. In other words, for the recycling of cleaning solvents, (b) distillation without changing the component ratio of the blended solvent as much as possible, (b) it can be used in the air conditioning room with less heat dissipation of the entire system (C) The running cost must be lower than or equal to the cost of purchasing and disposing of the solvent, etc. Absent.
March 15, 1999 First edition No. 7 published by Ohm Co., Ltd. “Easy knowledge of picture and air conditioning equipment” Authors Kazuo Otsuki, Katsumi Hasegawa

The cleaning waste liquid after washing the printing blanket device dissolves the ink and soluble components contained in the ink and the machine oil of the rotary press, and is soluble even if the solid component is removed in a sedimentation tank or filtered through a filter. Obviously it is difficult to remove the components. In other words, it is clear that in the regeneration of the washing waste liquid by the filtration method, the dissolved components accumulate each time the regeneration is repeated. Soluble components of the ink and oil of the rotary press are less likely to evaporate than the solvent. Therefore, in the present invention, a cleaning and regenerating method by an evaporation method is adopted in consideration of the characteristics, and a method for obtaining equipment costs and running costs that can be used for recycling of printing blanket cleaning waste liquid has been searched.
That is, in this invention, in order to distill without changing the component ratio of the (B) mix | blended solvent as much as possible, it distills at low temperature using sufficient reflux gas. (B) In order to reduce the heat dissipation of the entire system and enable it to be used in the air conditioning room, the heat of vapor condensation is transferred and used for evaporation to minimize the release of heat to the outside. To. (C) An object of the present invention is to make a power-saving device so that the running cost is lower than or equal to the cost of purchasing and discarding the solvent.

In order to repeatedly use the regenerated cleaning solvent, it is necessary to develop a method that does not change the components by distillation.
In the present invention, focusing on the fact that the cleaning solvent is required to have a characteristic that it is easy to dry and does not leave residual contamination after drying. A method to evaporate the solvent was developed. In addition, in order to minimize component change, by circulating a relatively small amount of gas in a sealed container, it is possible to repeatedly air-dry components that are difficult to evaporate, and to repeatedly pass components that do not easily aggregate through a condenser. Further, the change of the component ratio of the distilled regenerated solvent is minimized by recovering and aggregating a small amount of the vapor of the added component by circulating in the sealed container and collecting it without letting it escape to the atmosphere.

  In consideration of the property that soluble components of ink and oil of a rotary press are less likely to evaporate than solvents, the present invention adopts a cleaning regeneration method by an evaporation method, so that a blanket cleaning waste liquid for printing is used. Equipment costs and running costs that can be used for recycling can be obtained.

Specific embodiments of a distillation apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 is a principle diagram for explaining an embodiment of the present invention.
In the figure, 2 is an evaporation chamber, 5 is a coagulation chamber having a cyclone function, 1 is a mist generating chamber for generating mist by the ultrasonic element 12, 4 and 6 are heat exchangers, 1, 2, 3, 4, 5 and 6 are connected so as to generate a recirculation by a pipe line 7, and a blower 3 for generating a recirculation is provided in a part of the pipe line. The heat exchangers 4 and 6 are coupled so that heat flow is generated by the Peltier element 8, and heat is transferred in the direction of 4 to 6 by the current flowing through the Peltier element 8, and the gas passing through the heat exchanger 4 is cooled. The gas passing through the heat exchanger 6 is heated. The cleaning waste liquid is held in the cleaning waste liquid tank 11, introduced into the fog generating chamber by a pipe, and atomized by the ultrasonic element 12. The cleaning waste liquid in the form of mist is transported to the gas circulating through the entire apparatus by the piping 7 and is introduced into the evaporation chamber 2 to be vaporized. Reference numeral 13 denotes a drive source for driving the ultrasonic element 12.
FIG. 2 is a block diagram showing how the components 1 to 11 of the embodiment of the present invention described in FIG. 1 function. In this figure, the ultrasonic oscillator 12 and the drive source 13 for driving the ultrasonic element are omitted. However, the method of generating fog with an ultrasonic oscillator and an ultrasonic element is based on the same principle as that used in household ultrasonic humidifiers.
In FIG. 2, the annular flow path 7 is formed so that a reflux gas escape occurs in the order of 6-1-2-3-4-5, and a path is formed so as to return from 5 to 6. The blower 3 causes the gas flow in the annular flow path, and the blower 3 sucks the gas from the evaporation chamber 2 and accelerates and pressurizes it to send it to the heat exchanger 4 to form the entire flow in an annular shape. The vapor pressure of the solvent increases proportionally with temperature. That is, the higher temperature gas can contain more vapor than the lower temperature gas. From this principle, the gas heated by the heat exchanger 6 can contain more solvent vapor in the gas coming out from the outlet than in the gas coming in from the inlet of the warmer. That is, the circulating gas that has passed through the heat exchanger 6 is in a dry state. The cleaning waste liquid introduced from the waste liquid tank 11 into the mist generation chamber 1 becomes a mist state in the mist generation chamber 1, is mixed with the dry reflux gas from the heat exchanger 6, and is sent into the evaporation chamber 2. The evaporation chamber 2 has a cylindrical structure, and the circulating gas sucked together with the mist is introduced so as to rotate along the inner wall of the cylinder, and is rotated ten or more times along the inner wall of the tube and sucked into the pipe inserted in the center. And leave the evaporation chamber. This evaporation chamber is designed so that the cross-sectional area of the gas inlet is smaller than the cross-sectional area of the outlet, and since the outlet is sucked by the blower, the pressure is lower than that of the mist generating chamber 1, and the saturated vapor of the solvent The ratio of pressure to reflux gas is even greater. Moreover, since the mist-like solvent waste liquid has a large surface area ratio to the liquid contained in the mist, most of the components that evaporate while rotating along the cylindrical evaporation chamber wall can be vaporized. In addition, the component that does not evaporate is pressed against the wall surface by centrifugal force while rotating along the wall surface, and flows down along the wall surface. The waste liquid that has flowed down is collected in the concentrated waste liquid tank 9 and appropriately discarded.
The blower 3 sucks and pressurizes the saturated gas from the evaporation chamber 2 with the vapor of the cleaning solvent and transfers it to the heat exchanger 4. Since the gas that has passed through the blower 3 is in a pressurized state of +5 KPa to 10 KPa from the suction port, the solvent vapor contained in the gas is simultaneously pressurized and in a solvent saturated state. Furthermore, the circulating gas sent to the heat exchanger 4 is cooled and the temperature is lowered. Therefore, the vapor of the solvent that has been vaporized and integrated with the reflux gas is again atomized and fed into the aggregation chamber 5 together with the reflux gas. Since the coagulation chamber 5 is designed in the same manner as the cyclone, the mist adheres to the wall surface while rotating on the inner wall and aggregates and liquefies. The liquefied cleaning solvent is collected in a distillate tank provided at the lower part of the coagulation chamber and can be used as a regenerated liquid. Since this liquid is obtained by transferring the vaporized solvent waste liquid by the circulating gas, it does not contain solid components or components that are difficult to evaporate. In addition, since components that are relatively difficult to recover are also aggregated and recovered little by little while repeatedly passing through the coagulation chamber, it is possible to obtain a regenerated solution of a cleaning solvent close to the component ratio of the original cleaning agent. . The structure of the agglomeration chamber 5 is the same as that of the cyclone, but the diameter of the pipe at the outlet of the circulating gas is smaller in the cross-sectional area of the exhaust port of the cyclone. It is well known that the pressure loss increases when the diameter of the exhaust port is reduced in the cyclone. However, in the apparatus of the present invention, the pressure in the cyclone is maintained in order to add a function for recovering the solvent from the supersaturated gas of the solvent to the cyclone. As a result, a pressure difference occurs between the inside of the agglomeration chamber and the path leading to the heat exchanger through the exhaust pipe, and the reflux gas saturated in the agglomeration chamber has a solvent vapor amount below the saturation point in the piping. , No condensation.

Next, the distillation method of the present invention will be described numerically in correspondence with FIG. 1 and FIG.
Since the solvent for cleaning is a mixture, it varies depending on the formulation of the vapor pressure-temperature characteristics. Therefore, the description of the present invention will be made using xylene.
When xylene is distilled at a low temperature, nitrogen that does not cause an explosion is used. However, since physical properties such as specific heat of nitrogen are close to air, calculation is performed using air for explanation. The temperature difference that can be moved by the Peltier element is 60 ° C or more, but considering the efficiency of the heat exchanger, the temperature of the gas heated by the heat exchanger 5 is 50 ° C, and the temperature of the gas that can be cooled by the heat exchanger 4 is 15 ° C. Explain that distillation is possible when the difference is 35 ° C. Citing data published by the US National Bureau of Standards in 1969, the vapor pressure-temperature characteristics of xylene are
50 ℃ 25.5mHg
15 ℃ 3.5mHg
It is. Using this numerical value, the mixing ratio of the saturated gas of xylene at 50 ° C. and 1 atm is calculated as follows when the total pressure of the reflux gas is 760 mHg.
When the cleaning solvent vapor is saturated in the evaporation chamber, the amount of xylene carried from the evaporation chamber to the coagulation chamber is relative to the volume of the reflux gas.
25.5mHg ÷ 760mHg × 100 = 3.36%
When the cleaning solvent vapor is cooled by the heat exchanger 4 and enters the supersaturated state, and all the supersaturated solvent vapor is made liquid and collected in the coagulation chamber, the reflux gas becomes a saturated gas at 15 ° C, so fog is generated from the coagulation chamber. The amount of solvent carried by the gas circulating in the chamber
3.5mHg ÷ 760mHg × 100 = 0.46%
It is.
Therefore, the amount of cleaning solvent recovered by the reflux gas is the vaporized volume ratio.
3.36%-0.46% = 2.9%
It is. Using the fact that the volume of the vaporized state of the compound of 1 gram molecule is 22.4 liters at 20 ° C., the amount of the reflux gas necessary for recovering 1 liter of solvent is calculated as follows.
Since the molecular weight of xylene is (C ₈ H ₁₀ ), the molecular weight is 106.
Therefore, when 106 g of xylene is vaporized at 20 ° C., it becomes 22.4 liters of gas. Since the specific gravity of xylenes is between 0.857 and 0.876, the weight of 1 liter of xylene using 0.86 is
1000 × 0.86 = 860g
The volume when 1 liter of xylene vaporizes is
860 ÷ 106 × 22.4 = 181.74 liters.
So the amount of reflux gas needed to recover 1 liter of solvent is
181.74 ÷ 0.029 = 6,267 liters. That is, it can be seen that 1 liter of xylene can be recovered per minute when refluxing is performed with a blower having a blowing capacity of 6.3 m ³ / min.
In general, the amount of cleaning solvent used in one large rotary press is 20 to 30 liters per day. Therefore, when averaged over an operating time of 8 hours, it is 2.5 liters to 3.75 liters per hour and 0.042 liters to 0.063 liters per minute. That is, the amount of reflux gas is
6.3 × 0.063 = 0.4m ³ / min
If you check a commercially available blower, you can use 60W or less of power. The gas to be circulated here is determined by the internal volume of the apparatus because it repeatedly circulates in the annular flow path of the apparatus. The prototype device was about 20 liters.

Next, the amount of heat transferred by the Peltier element is calculated.
The heat of vaporization of xylene is 80-100 cal per gram.
The heat of evaporation per liter is calculated using a specific gravity of xylene of 0.86.
1000 × 0.86 × 100 = 86000 cal.
When distilling xylene, it is possible to vaporize all 1 liter by applying 86 kcal heat to 1 liter of liquid xylene. In addition, if 181.74 liters of gaseous xylene is cooled and 86 kcal is taken away, 1 liter of liquid is obtained. That is, in the distillation operation, if heat is absorbed on the agglomeration side and radiated on the evaporation side, heat is not exchanged with the outside, so heat is not released to the periphery.
One such heat transfer means is a Peltier element. Next, an example in which a distillation apparatus is made using a Peltier element is calculated.
The amount of heat transferred per hour with an hourly recovery amount of 3.75 liters from the consumption mentioned above is
3.75 × 86000cal = 322500cal …… It is 323Kcal. When converted to electric power
323 x 1.163 = 375.65 W / h
Because the efficiency of the Peltier element when obtaining a temperature difference of 35 ° C is about 50%
375.65 ÷ 0.5 ＝ 751w / h
It becomes. It is obvious that the running cost in this case is sufficiently low and can be used even in a small-scale printing factory, and contributes to the reduction of waste.
Here, since the power loss added to the power used at an efficiency of 50% becomes heat, the prototype device is used to raise xylene from room temperature to 50 ° C, and to raise the temperature of the evaporation chamber to 50 ° C. As a result, the amount of heat generated outside the apparatus was sufficiently low.
Next, the recirculating gas flows through the recirculating flow path with the solvent vapor, and the amount is 1 hour
0.4 × 60min = 24m ³ / h
Will circulate. This air is raised from 15 ° C to 50 ° C on the evaporation side and from 50 ° C to 15 ° C on the cooling side.
The amount of heat transferred at this time is
0.2 × 1.2 × 24 × (50−15) = 241.92 kcal
Here, 0.24 is the specific heat of air kcal / kg / ° C., and 1.2 is the specific gravity of air 1 kg / m ³ .
This amount of heat is small compared to the amount of heat transferred for the evaporation-liquefaction of xylene. Moreover, in the experiment conducted with the prototype device, the temperature difference in the case of heat transfer by the Peltier element described at the beginning of the description of this example was 50 ° C-15 ° C = 35 ° C, but the Peltier element has a temperature of about 60 ° C. Since the difference can be generated, the heated reflux gas has risen to close to 60 ° C, and when the solvent is evaporated, the reflux gas gets heat from the evaporation chamber, and the entire reflux gas becomes a saturated gas of 50 ° C. ing. On the cooling side, the temperature of the surface of the heat exchanger is 5 ° C. or less, and it is considered that the movement of the amount of heat of heating and cooling of the circulating gas is included in the loss of the Peltier element and the heat exchanger.

  Further, the heat transfer method is not limited to the Peltier element. Heat can be transferred by disposing the heat absorption side of the cooling device used in the air conditioner or refrigerator in the aggregation chamber and the heat dissipation side in the evaporation chamber. When the distillation apparatus of the present invention is configured using this heat transfer means, the power efficiency is about 30% to 40%.

Next, the structure of the evaporation chamber 2 will be described with reference to FIG.
The reflux gas in which the mist of the to-be-distilled cleaning liquid generated in the mist generating chamber 1 of the mist generating means is diffused is introduced along the inside of the outer wall of the cylindrical evaporation chamber 2, and is introduced into the inner wall of the cylindrical evaporation chamber 2. The liquid of the fine particles that make up the mist is evaporated to form a vapor diffused in the reflux gas. Vapor mixed with a lightweight reflux gas that can be collected on a cylindrical wall surface and flow down along the wall surface and easily reach the center against the centrifugal force, together with the reflux gas, from the ceiling plate of the cylindrical evaporation chamber 3 to the cylinder The gas introduction part and the gas discharge part which were made to introduce into the exhaust pipe inserted in the center of this were provided.

  FIG. 4 shows that an ultrasonic jet is generated in the mist generation chamber 1 using the ultrasonic element 12 to generate a mist of waste liquid in response to the flow of the circulating gas and the waste liquid flow. It shows the means to introduce.

  FIG. 5 shows that the nozzle 14 is arranged in the mist generating chamber 1 instead of the ultrasonic element 12 shown in FIG. 4, and a waste liquid stream is ejected from the nozzle 14 to generate a mist of the waste liquid. Means to be introduced into the chamber 2 is shown.

It is the principle figure shown in order to demonstrate embodiment of this invention. It is a block diagram which shows the function of the component of this invention. It is explanatory drawing of an evaporation chamber and its peripheral apparatus. It is explanatory drawing which shows the fog generation means in the fog generation chamber by an ultrasonic oscillator. It is explanatory drawing which shows the "fog generation in the fog generation chamber by a nozzle."

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fog generation chamber 2 Steam chamber 3 Blower 4 Heat exchanger 5 Coagulation chamber 6 Heat exchanger 7 Piping path 12 Ultrasonic element 14 Nozzle

Claims (4)

  Cylindrical evaporation chamber, condensing chamber having a cyclone function by constricting the lower part of the cylindrical tube, a mist generating chamber provided with an ultrasonic oscillator as mist generating means, and an evaporation chamber-coagulation chamber -A pipe line that forms a gas circulation passage that makes a round of the mist generation chamber, and a blower for generating a circulation flow between the evaporation chamber and the coagulation chamber and between the coagulation chamber and the mist generation chamber, Furthermore, two heat exchangers are arranged between the evaporation chamber, the coagulation chamber, the coagulation chamber, and the fog generation chamber. Are connected by a heat transfer means, absorbs the heat of the circulating gas from the heat exchanger arranged between the evaporation chamber and the coagulation chamber, and moves to the heat exchanger arranged between the coagulation chamber and the fog generation chamber by the heat transfer means A waste liquid distillation regenerator that has a structure that dissipates heat into the reflux gas.   2. The distillation apparatus according to claim 1, wherein the mist generating means is sprayed by a nozzle.   In Claim 1, the reflux gas in which the mist of the waste liquid to be distilled generated by the mist generating means is diffused is introduced along the outer inner wall of the cylindrical evaporation chamber, and along the inner wall of the cylindrical evaporation chamber. The liquid of the fine particles that make up the mist is evaporated to form a vapor diffused in the reflux gas, and at the same time, the foreign particles contained in the mist and the liquid particles that are concentrated because they are difficult to evaporate Collected from the ceiling plate of the cylindrical evaporating chamber from the ceiling plate of the cylindrical evaporation chamber to the center of the cylinder. A cleaning waste liquid distillation regenerator characterized by a cylindrical evaporation chamber provided with a gas introduction part and a gas discharge part introduced into an inserted exhaust pipe.   The heat transfer device according to claim 1, wherein the heat absorption side of the Peltier element is in pressure contact with a heat exchanger provided in a pipe line connecting the evaporation chamber and the aggregation chamber, and the heat dissipation side of the Peltier element is a tube connecting the aggregation chamber and the fog generation chamber The pressure of the heat exchanger installed in the channel is pressed to remove heat from the recirculated gas containing a large amount of steam via the evaporation chamber, lowering the temperature of the gas and reducing the partial pressure value of the solvent that can be mixed in the recirculated gas. In this way, the temperature of the reflux gas is increased by introducing the solvent into the coagulation chamber as a supersaturated gas of the solvent, and heating the reflux gas that does not contain much vapor via the aggregate. 2. The cleaning waste liquid distillation regeneration apparatus according to claim 1, wherein the distillation efficiency of the cleaning waste liquid is increased by a method of increasing the partial pressure value of the solvent to facilitate evaporation in the evaporation chamber.

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