JPH027997A - Distiller for dry cleaner - Google Patents

Abstract

PURPOSE:To grasp surely solvent gas temperature since the beginning of distillation for preventing the solvent from abrupt boiling and erroneous distribution by bringing a portion of mixed solvent drained in contact to a distiller directly with a temperature detecting portion of a temperature sensor. CONSTITUTION:Mixed drained liquid comprising at least two kinds of organic solvents soluble in each other and having different boiling points is fractionally distilled and recovered by a distilling apparatus comprising a distiller 150, condenser 27, cooler 26 and water separators 22, 22a. Further, there are provided a temperature sensor 32 provided in the distiller 150 to measure evaporated gas temperature, a heater 31 for the distiller 150 controlled by the signal of the temperature sensor 32 and a distribution piping for recovered solvent. When the mixed solvent is drained to the distiller 150, a portion of the drained liquid is brought into contact directly to the temperature detecting portion of the temperature sensor 32. Thus, the solvent gas temperature can be surely grasped since the beginning of distillation, so that the abrupt boiling of solvent and erroneous distribution thereof can be prevented.

Description

Detailed Description of the Invention (Field of Graduation Application) The present invention relates to a distillation device applied to a dry cleaner that uses a mixture of two or more organic solvents with different boiling points, such as perchlorethylene and Freon R113. be.

(Prior Art) A conventional distillation system for a dry cleaner will be explained with reference to FIG.

The distiller 150 is equipped with a temperature sensor 32 that measures the temperature of evaporated gas. A heating tank 31 using steam as a heat source is provided at the bottom of the distiller 150.

The heating tank 31 is provided with two systems of steam supply piping 340, 350, one for a low boiling point solvent and one for a high boiling point solvent, which are opened and closed by dedicated automatic valves 34, 35. 36 is a steam trap. Steam supply piping 340 for low boiling point solvent
The steam supply pipe 350 is designed to allow a small flow of steam to flow at low pressure or by providing an orifice or the like in the pipe, and the high boiling point solvent steam supply pipe 350 is designed to allow a high pressure and large flow of steam to flow.

Now, here is 30% of the mixed solvent that was centrifuged after washing the clothes.
is discharged from the valve 12 to the distiller 150 by the pump 10 through the pipe 11, and when distillation starts, the distillation status is detected by the temperature sensor 32 at the evaporated gas temperature of the mixed solvent 30 in the example shown in FIG. Depending on the gas temperature, the controller 33 opens the low boiling point valve 34 when the temperature is low.
When the temperature is high, the high boiling point valve 35 is opened, heating is performed according to the solvent composition, and the mixed solvent is distilled in the shortest possible time without bumping accidents.

On the other hand, the evaporated solvent gas is condensed in the condenser 27,
It is led to the distribution piping via the cooler 26.

When the evaporated gas temperature is low, the valve 23 is opened by a signal from the controller 33, and the water separator 2 for low boiling point solvents is opened.
2, when the gas temperature rises above a certain temperature (hereinafter referred to as fractional distillation temperature) as the distillation progresses, the valve 23 is closed and switched to the water separator 22a for high boiling point solvents. Each solvent is separated and recovered in a dedicated tank (not shown).

(Problems to be Solved by the Invention) As described above, in the distillation separation of mixed solvents, by detecting the ever-changing evaporated gas temperature (these are the same as the boiling point temperature), it is possible to Low-pressure steam is supplied to maintain a low-temperature range to perform stable distillation without bumping, and a distribution valve leads it to a water separator for low-boiling solvents, so that when the boiling point rises above a certain temperature, 1
．． This time, we switched to high-pressure steam to maintain the high temperature range, and switched to a water separator for high-boiling solvents to perform fractional distillation.

However, at the initial stage when the mixed solvent was drained into the distiller,
The temperature sensor senses the effect of heat dissipation from the distiller wall, which is higher than the fractionation temperature, and is still detecting a high temperature.

For this reason, in conventional distillation methods, high-pressure steam is suddenly supplied from the beginning of distillation and enters the high-temperature region, resulting in bumping, and low-boiling solvents are mistakenly collected in a water separator for high-boiling solvents. This resulted in a significant imbalance in the solvent composition and the amount of each solvent to be distributed.

In order to improve these problems, after the distillation of high-boiling solvents is completed, steam is cut off at both high and low pressure until the next time it is drained to lower the heat capacity of the distiller, or steam is forced for a certain period of time after the start of distillation. Methods such as supplying low-pressure steam and keeping the distribution valve on the low-boiling point solvent side have been taken, but in either case, although they could be effective measures, they still caused the above problems. .

The present invention was developed in light of these circumstances, and is designed to accurately grasp the solvent gas temperature from the beginning of distillation, especially in dry cleaners that clean using two or more solvents with different boiling points, and to prevent bumping and misdistribution of the solvent. The purpose of this invention is to provide a distillation apparatus that eliminates this problem.

(Means for Solving the Problems) Therefore, the present invention comprises a distiller, a condenser, a cooler, and a water separator, and is capable of fractional distillation of a mixed waste liquid of at least two or more mutually soluble organic solvents having different boiling points. A fractionator for recovery, a temperature sensor installed inside the distiller to measure the temperature of the evaporated gas, and a steam W! controlled by the signal from the temperature sensor. In a dry cleaner distillation apparatus equipped with a heating device and a distribution pipe for recovered solvent, a portion of the mixed solvent can be brought into direct contact with the temperature measuring part of the temperature sensor when draining the mixed solvent into the distiller. The present invention is configured to do this, and is intended to be a means of solving the above problem.

(Function) When the degree of mixing of two or more organic solvents such as perchlorethylene and Freon R113, which are mutually soluble and have different boiling points, is separated by distillation by detecting the evaporated gas temperature using a temperature sensor, the exhaust gas to the distiller is By guiding a portion of the liquid to a temperature sensor and cooling it in advance, the temperature of the low-boiling solvent gas generated in the early stages of distillation can be detected quickly and accurately.

Therefore, the ever-changing evaporated gas temperature (boiling point) can be detected accurately from the beginning of distillation, preventing erroneous detection from deteriorating the balance between the composition of the recovered solvent and the amount of fractionated solvent, and preventing bumping accidents. To efficiently distill a mixed solvent in the shortest possible time while preventing the occurrence of

(Example) Hereinafter, a typical example of the present invention will be described based on FIG. 1.

In the same figure, parts with the same reference numerals as ψ)A, 3 and 4 are substantially the same parts, 10 is a pump, I
J is a pipe connecting the same pump 10 and the distiller 1.50, 12 is a valve installed in the same pipe 1, and 2222a is a water separator for low boiling point solvent and high boiling point) H agent. Separator 2
2 and 22a are connected to the condenser 27 by the pipe 11 via the switching valve 23 and the cooler 2G, and the condenser 27
is connected to the distiller 150 through piping. Switching valve 2
3 is operated by a controller 33.

A temperature sensor 32 is installed inside the distiller 150,
A detection signal is sent to the controller 33. 31 is a heating tank provided at the bottom of the distiller 150, and a valve 34 or 35 is operated by the controller 33 to supply a steam supply pipe 340 for a low boiling point solvent or a steam supply pipe for a high boiling point solvent to the heating tank 31. Low pressure (low flow rate) steam or high pressure (high flow rate) steam is supplied via piping 350 . 36 is a steam trap.

The above is substantially the same as the conventional device shown in FIG. The pipe 3 is branched, and its tip is directed toward the temperature measuring section of the temperature sensor R4.

Now, to describe the operation of the apparatus of this embodiment, a mixed liquid 30 of two or more organic solvents, such as perchlorethylene and Freon R113, which are dissolved in each other and have different boiling points, used in the cleaning process is pumped into a pipe by a pump 10. 11 and is drained from valve 12 to distiller 150. At this time, a part of this drained liquid passes through the pipe 13, which is thinner than the pipe 11, to the temperature sensor → J.

You will also be guided to the temperature measuring section at -32.

As a result, even if the internal temperature of the distiller 150 is higher than the fractionation temperature (which is set at 76° C. in this example), the temperature sensor 32 detects the temperature of the drained solvent (generally set at 25° C.). It will be cooled to around 30°C).

Therefore, the low-boiling point valve 34 is opened according to instructions from the controller 33, and the steam is supplied to the low-boiling point solvent steam supply pipe 3.
Steam at a low pressure or a small flow rate is supplied from 40 into the heating tank 31 to start distillation, and the switching valve 23 also opens the passage for the low boiling point solvent, so that the low boiling point solvent in the early stage of distillation does not bump. The water is reliably led to the water separator 22 for low boiling point solvents and collected in a dedicated tank.

As the distillation progresses, the gas temperature rises moment by moment, and when the temperature detected by the temperature sensor 32 reaches the set fractional distillation temperature (76°C in this example), the distillation becomes extremely slow with low-pressure steam. Therefore, the high boiling point valve 35 is switched, and the valve 23 is also switched, and all the remaining liquid is led to the water separator 22a for high boiling point solvents and collected in a dedicated tank.

In the above explanation, steam is used to heat the distiller, but similar effects can be obtained by replacing this with an electric heating source of varying heating capacity and controlling both by the distillate temperature or evaporated gas.

(Effect of the invention) The effects of the present invention will be explained below based on FIG. 2.

The solid line in FIG. 2 shows a change in temperature detected by a temperature sensor according to the prior art, and the broken line is a data line showing a similar change according to the present invention.

As is clear from the figure, in the conventional technology, there is a time delay before the gas temperature of the low-boiling point solvent generated in the early stage of distillation can be accurately detected, and in the hunting part, the low-boiling point solvent is mistakenly detected as having a high boiling point. The result is that it is collected on the solvent side and the composition is significantly disturbed.

On the other hand, in the method of the present invention, the gas temperature is detected quickly and accurately, indicating that stable fractional distillation is always performed.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a distillation system of a dry cleaner showing a typical embodiment of the present invention, Fig. 2 is a data diagram showing changes in temperature detected by a temperature sensor according to the prior art and the present invention, and Fig. 3 is a diagram of a dry cleaner distillation system showing a typical embodiment of the present invention. It is a distillation system diagram of a cleaner. Explanation of the main parts of the diagram 10 - Pump 13 - (for temperature sensor cooling) piping 22.22a - Water separator 23 - (switching) valve 30 - Mixed solvent 32 - 3 temperature sensors - Controller 34.35 - (steam) valve 150 --- distiller

Claims (1)

[Claims] It consists of a distiller, a condenser, a cooler, and a water separator, and a fractionator that collects a mixed waste liquid of at least two mutually soluble organic solvents with different boiling points by fractional distillation. A temperature sensor that measures temperature;
In a dry cleaner distillation device that is equipped with a heating device for the distiller that is controlled by the signal from the temperature sensor and a distribution pipe for the recovered solvent, when the mixed solvent is drained to the distiller, a portion of the mixed solvent is heated to the above temperature. A distillation device for a dry cleaner, characterized in that it is configured so that it can be brought into direct contact with a temperature measuring part of a sensor.