JPS585081B2 - How to dispose of liquid residue - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating liquid residue, particularly a method for efficiently treating liquid residue containing solids in a complex manner by utilizing internal heat generation in a crushing cylinder of a vibration mill. .

Distillation and extraction operations are widely carried out in chemical factories, pharmaceutical factories, food factories, etc., and during such operations, a large amount of liquid residue containing solids is generated.

This residue generally contains various organic solvents,
Furthermore, since it has a strong odor, it is not appropriate to dispose of it as it is by incineration or landfill, and it is also extremely uneconomical to dispose of it as it is.

Therefore, conventionally, the liquid residue as described above is evaporated in advance, and the evaporation residue is disposed of as described above, while the evaporated organic solvent, for example, is recovered and adjusted for reuse. This processing method is being used.

However, conventional methods for treating liquid residue generally involve treating the liquid residue in a heating iron containing a heating coil and stirring blades, and therefore have the following various drawbacks.

・During the process of evaporating the liquid residue, which is already somewhat viscous, the liquid residue turns into slurry and becomes extremely viscous, so it must be sufficiently stirred using a so-called rotary stirrer, typically a stirring blade. I can't do it,
Therefore, there is a risk of abnormal overload and bumping, and a significant decrease in thermal efficiency due to burning of the heating coil, making it extremely difficult to completely evaporate the liquid residue.

Since it is extremely difficult to completely evaporate the liquid residue, the recovery rate of organic solvents, for example, is low, and the solid content as the evaporation residue contains organic solvents, so it is difficult to completely evaporate the liquid residue. If it is disposed of as is by incineration or landfill, there is a strong risk of causing pollution problems, and if it is only solid content, it is wasted even if it has high utility value, such as something that can be used as feed or fertilizer. I have no choice but to dispose of it.

・Regardless of whether it is complete or incomplete, after the evaporation process, work to remove burnt on the heating coil, work to remove evaporation residue adhering to the inside of the heating iron, large lumps inside the heating iron. They are forced to perform a variety of extremely difficult tasks, such as removing the evaporation residue that tends to occur.

The present invention provides an improved method for treating residual liquid that eliminates the drawbacks of the conventional treatment methods as described above, and its purpose is to efficiently and completely treat residual liquid. Another purpose is to take out the solid content remaining after evaporation as a dried and pulverized product, and to completely recover, for example, organic solvents in the remaining liquid, thereby eliminating at least the possibility of causing a pollution problem. Another object of the present invention is to avoid having to perform various difficult operations in the conventional treatment methods described above when treating residual liquid.

The present invention, which achieves these objects, is comprised of the following elements, with the gist of evaporating the residual liquid while stirring and mixing it using internal heat generation in the crushing tube of a vibrating mill. There is.

(a) Evaporating the residual liquid while stirring and mixing using internal heat generation in the crushing tube of the vibrating mill.

(b) Obtaining a dry and simultaneously ground solid content as an evaporation residue.

(C) Condensing and recovering the vapor of the evaporated liquid.

The present invention, which is composed of the above elements, includes:
A method using a vibrating mill equipped with a jacket around the outer periphery that can use the heat of a heat transfer medium introduced separately if necessary, and the vapor of the evaporated liquid is condensed in a cooling tower via a gas-liquid separator. a vibratory mill containing multiple elongated rondos as the grinding medium;
The methods include a method of using a so-called batch-type vibrating mill, a method of bringing the inside of the crushing cylinder of the vibrating mill into a reduced pressure state, and an appropriate combination of these methods.

Hereinafter, the configuration will be described in detail based on the drawings, which are process diagrams as an example of embodying the present invention.

As shown in FIG. 1, which is an overall process diagram, the liquid residue containing solids is supplied from the residue tank 1 through the valve 2 and pump 3 into the crushing cylinder 5 of the vibrating mill 4. Ru.

The vibrating mill 4 converts the rotational force of a motor 7 into vibration accompanied by a certain kind of eccentric rotation and transmits it to a crushing cylinder 5 supported by a spring 6 using a crushing medium built in the crushing cylinder 5. With the assistance of It is used especially as a pulverizer.

However, according to the tests conducted by the present inventor, a vibrating mill in which the crushing media such as heavy crushing balls and crushing irons, which are built in the crushing cylinder 5 with an apparent volume ratio of approximately 60 to 80%, collide violently. 4, approximately 60 to 70% of the rotational force of the motor 7 is converted into thermal energy.

For example, when a grinding medium is put into the grinding cylinder 5 and the motor 7 is rotated, the temperature inside the grinding cylinder 5 quickly rises to 200° C. or higher under the conditions under which the vibration mill 4 is generally used.

As described above, the gist of the present invention is to utilize such internal heat generation in the crushing tube 5 of the vibrating mill 4 to perform stirring,
The remaining liquid is evaporated while mixing.

The residual liquid supplied into the crushing cylinder 5 is heated by the internal heat generation described above, and the liquid in the residual liquid evaporates.

If this hardening is done, the crushing tube 5 will be
It is also possible to use a vibrating mill 4 provided with a jacket 8 around the outer periphery of the vibrating mill 4, to circulate steam as a heat medium through this jacket 8, and to use the heat of the steam in combination to achieve more rapid evaporation.

Also, a suction device 10 connected to the crushing cylinder 5 at the end.
It is also possible to operate a vacuum pump to reduce the pressure inside the crushing cylinder 5.

The liquid vapor in the remaining liquid that evaporates in this way is
The cooling water is condensed in the cooling tower 11 in which it is circulated,
It is collected in the collection tank 12.

However, a preferred embodiment of the present invention is to provide liquid vapor to the cooling tower 11 via a gas-liquid separator 13 between the crushing cylinder 5 and the cooling tower 11.

This is because when the residual liquid is heated in the crushing tube 5, the residual liquid may cause bumping even if it is sufficiently stirred and mixed in the crushing tube 5. This is because the residual liquid containing solids accompanies the liquid vapor and scatters, so it is necessary to separate the residual droplets containing solids from the liquid vapor.

In an example shown in FIG. 1, a cyclone type gas-liquid separator 1
3 is used, the evaporated and scattered from the crushing cylinder 5 are introduced into the gas-liquid separator 13, and the vapor of the evaporated liquid and the remaining droplets containing the scattered solids are separated. Only the vapor of the liquid is supplied to the cooling tower 11, and the remaining droplets containing solids are returned to the crushing tube 5 via the air seal rotary valve 14, the intermediate tank 15, and the air seal rotary valve 16.

At this time, one of the air seal rotary valves 14 and 16 must be closed to prevent backflow.

In this way, the residual droplets in the crushing tube 5 are sequentially evaporated, but during this time, as shown in FIG. At the same time, the solids contained in the droplets continue to be crushed while increasing their concentration.

The grinding medium 17 used here may be a grinding ball that is generally used in a vibration mill, but as the evaporation process progresses and the viscosity of the remaining droplets gradually increases, the balls may In some cases, it becomes difficult to sufficiently stir and mix the residual material, so in this embodiment, a long and thin rod for crushing is used.

Eventually, the liquid remaining in the droplets, such as the organic solvent, is completely removed and recovered, and only the crushed and dried solids and the crushing medium 17 remain in the crushing cylinder 5.

Finally, while continuing to vibrate the vibrating mill 4, the crushing tube 5 is passed through the perforated plate 18, which has a large number of holes that do not allow the crushing media 17 to pass through, but allow the crushed and dried solids to pass through. The solid content is discharged by operating the rotary valve 19 for air sealing, which communicates with the inside.

Specifically, for example, a bag filter (not shown) may be attached to the tip of the rotary valve 19 for the air jet rule, and solids can be discharged and collected at the same time while being suctioned by a suction fan (not shown).

After completing such a series of processes, no solid matter adheres or remains in the crushing tube 5 due to the so-called self-cleaning action of the crushing media.

The vibration mill 4 used here may be a so-called continuous type vibration mill in which a plurality of crushing tubes are arranged in series, but depending on the nature of the droplets remaining, In order to completely remove the liquid by evaporation, a so-called batch-type vibratory mill is preferred, as shown in FIG.

As explained above, the present invention has the following effects.

(1) Since internal heat generation in the crushing tube of the vibrating mill is utilized, residual droplets can be removed extremely efficiently and completely.

(2) Since it is a method that can completely evaporate residual droplets, for example, organic solvents can be completely recovered and therefore do not cause pollution problems.

(3) Since a crushed and dried solid content can be obtained, if the solid content has value as feed or fertilizer, for example, it can be used as is.

(4) Due to the self-cleaning action of the grinding media, solid matter does not adhere to or remain inside the grinding cylinder, making it easy to work throughout the process.

[Brief explanation of the drawing]

FIG. 1 is a process diagram as an example of carrying out the present invention;
FIG. 2 is a longitudinal cross-sectional view of a main part of a vibrating mill as an example used in carrying out the present invention, with some parts omitted. 1... Residual tank, 4... Vibration mill,
5...Crushing cylinder, 7...Motor, 8.
... Jacket, 10 ... Suction device, 1
1... Cooling tower, 12... Recovery tank,
13... Gas-liquid separator, 15... Intermediate tank, 17... Grinding medium.

Claims (1)

[Claims] 1. A liquid residue containing solids is stirred and mixed using internal heat generation in the crushing cylinder of a vibrating mill, and evaporated while being mixed to obtain a dried and pulverized solid content. A method for processing liquid residue by condensing and recovering the vapor of the liquid. 2. The method for treating liquid residue according to claim 1, which uses a vibration mill equipped with a jacket around which a heat medium flows. 3. The method for treating liquid residue according to claim 1, wherein the vapor of the evaporated liquid is condensed and recovered by exchanging heat with cooling water through a gas-liquid separator. 4. The method for treating liquid residue according to claim 1, wherein the vibrating mill is a vibrating mill that uses a plurality of elongated irons as a grinding medium. 5. The method for treating a liquid residue according to claim 1 or 2, wherein the vibration mill is a so-called batch-type vibration mill consisting of only one crushing cylinder. 6. A method for treating a liquid residue according to claim 1 or 2, wherein the inside of a crushing cylinder of a vibration mill is brought into a reduced pressure state.