JP2849149B2 - Pressure crystallization equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pressure crystallizer, and more particularly, to a small-capacity pressure crystallizer.

(Prior art) Pressure crystallization has great potential for application to raw material systems that are difficult to separate by conventional distillation and cooling crystallization, and that high-purity products are easily obtained. This is a separation and purification technique that has attracted a great deal of attention in recent years as the chemical industry has become finer, because of its easy yield and low energy consumption.

FIG. 4 shows a typical example of a conventional pressure crystallization method and apparatus, which will be described below. A high-pressure container formed by tightly fitting a lid (3) into a lower opening of a pressure-resistant cylinder (1) having a cylindrical filter (2) disposed on an inner peripheral wall, and fitting a piston (4) through an upper opening. the crystallization chamber (8) in (9), a raw material feed pump P, the pre-crystallizer D via a valve V ₁ is connected with a raw material supply pipe (5), and,
Filter (2) drain valve V ₂ and vacuum nozzle N to the liquid discharge port (6) communicating with the lower back is a tube connected, is connected further drainage tank T.

When pressure crystallization is performed by the above apparatus, first, the raw material is cooled in a preliminary crystallizer D to generate a seed crystal for pressure crystallization, and then the crystallization chamber (8) is supplied from the raw material supply pipe (5). In a state where the valves V ₁ and V ₂ are closed, the raw material in the crystallization chamber (8) is pressurized to a predetermined pressure by the piston (4) to crystallize a specific substance and to coexist in a predetermined solid-liquid state To Then, immediately open the drain valve V _2, to lower the piston (4) while maintaining the pressure, the filter (2), the valve V _2, the liquid phase to the liquid discharge tank T through the vacuum nozzle N Discharge. In the normal case, the remaining liquid between the crystal grains is squeezed out further by pressing and pressing,
Discharge. When the piston (4) is subsequently lowered, it is formed into a lump solid product, and then the liquid phase pressure in the crystallization chamber (8) gradually decreases, and the crystal surface partially melts, so-called sweat washing is performed, and the lump solid is removed. The product is refined.

When the discharged liquid phase pressure drops to a predetermined pressure, the lowering of the piston (4) is stopped, and after the piston (4) is raised, the solid product on the lid (3) is taken out by the pusher (7) or the like. Thereafter, the cylindrical body (1) is lowered and fitted to the lid (3). Thereafter, the process returns to the raw material injection step, and the same steps are repeated to produce a product.

(Problems to be Solved by the Invention) By the way, when the liquid phase is discharged from the crystallization chamber (8), the drainage rate per unit area of the filter (2) (hereinafter, referred to as
When the actual drainage rate is small, the crystals are easily captured by the filter, and the crystal layer formed thereby exhibits a filter-like effect, so that the product yield is high. If it is large, the crystals will easily pass through the filter, and the product yield will decrease.

Thus, in order to reduce the actual drainage speed, the liquid phase discharge circuit is provided with the pressure reducing nozzle N as described above. Since the diameter of the nozzle cannot be reduced to 0.10 mmΦ or less from the viewpoint of production, a nozzle having a diameter of 0.10 mmΦ or more is usually used. In the case of a large-capacity pressure crystallization apparatus, the required actual drainage speed can be adjusted.

However, in the case of a small-capacity pressure crystallizer, use a decompression nozzle with a minimum nozzle diameter of 0.10 mmΦ, and reduce the drainage rate at the nozzle as in the case of a large-capacity pressure crystallizer. However, since the actual drainage speed is high, the product yield is low.

Therefore, in the case of a pressure crystallizer having a small capacity, a drainage valve is connected to a drainage port by a drainage pipe and a pressure-resistant drainage vessel having a pressurizing mechanism are connected in this order as a separation liquid discharge means ( The pressure in the vessel can be adjusted by the pressurizing mechanism in accordance with the pressure in the crystallization chamber at the time of drainage, so that the actual drainage speed is reduced to the required low speed. Can be controlled. However, when applied to a raw material system in which the amount of drainage is extremely large compared to the amount of crystallization in the pressure crystallization method, the capacity of the pressure-resistant drainage container needs to be substantially the same as that of the high-pressure container. There is a problem that the entire apparatus becomes large (not compact) and the cost of the apparatus increases.

The present invention has been made in view of such circumstances, and has as its object to solve the above-mentioned problems of the conventional apparatus, and to reduce the actual drainage in the case of a small-capacity pressure crystallization apparatus. An object of the present invention is to provide a pressure crystallization apparatus in which the speed can be controlled to a low speed and the whole apparatus is more compact than in the case of the T-type drainage means.

(Means for Solving the Problems) In order to achieve the above object, a pressure crystallization apparatus according to the present invention has the following configuration.

That is, the device according to claim 1 includes a high-pressure container, a mixture supply unit into the container, a pressurizing unit for the mixture in the container, a solid-liquid separation mechanism for the solid-liquid mixture in the container, In a pressure crystallization apparatus having a separation liquid discharge means capable of controlling a separation liquid discharge speed from a container, a liquid discharge port of a high-pressure container and a pressure-resistant discharge container having a pressurizing mechanism are connected by a drain pipe. A pressure crystallization apparatus characterized in that a liquid discharging means from the drainage container is provided to constitute the separated liquid discharging means.

According to a second aspect of the present invention, the liquid discharging means of the pressure-resistant drainage container includes a flowing liquid pipe branched from the middle of the drain pipe, and a flowing liquid valve and a pressure reducing nozzle provided in the pipe. The pressure crystallization apparatus according to claim 1.

The apparatus according to claim 3 is the pressure crystallization apparatus according to claim 1, wherein a plurality of the separated liquid discharge means are connected in parallel to the liquid discharge port.

(Operation) Since the pressure crystallization apparatus according to the present invention is configured as described above, the following pressure crystallization can be performed.

First, after the raw material is injected by the same process as in the case of the conventional apparatus and the pressure is increased to a predetermined pressure, the liquid discharge flow path of the liquid discharge means from the pressure-resistant discharge container constituting the separated liquid discharge means is closed. When the pressure in the pressure-resistant drainage vessel is adjusted to a slightly smaller value than the pressure in the high-pressure vessel by the pressurizing mechanism at the same time as opening the line of the drainage pipe, Even in this case, the liquid can be discharged from the high-pressure container into the drainage container by controlling the actual drainage speed to a required low speed.

If the capacity of the drainage container is made smaller than the capacity of the high-pressure container, the amount of liquid in the drainage container becomes full before all the liquid in the high-pressure container comes out. Therefore, next, at or immediately before the drainage container is filled with the drainage liquid, the liquid discharge passage of the liquid discharging means is opened, and the pressure in the drainage container is slightly smaller than the pressure in the high-pressure container. When adjusted to a small value, the liquid in the high-pressure container and the liquid in the drainage container merge and are discharged through the liquid discharge passage of the liquid discharging means. Since the liquid is discharged from the inside and the pressure from the inside of the high-pressure vessel can be reduced, the liquid can be drained with the actual drainage speed set to a small state.

Next, immediately or in the middle of the drainage, the liquid discharge passage of the liquid discharging means is closed, the pressure in the drainage container is adjusted, and the actual drainage speed is controlled to a required low speed, so that the drainage container The drainage into the drainage container is started, and thereafter, the drainage into the drainage container and the discharge of the liquid from the high-pressure container and the drainage container as described above are repeated. In this case, the actual drainage speed can always be controlled to the required low speed for drainage.

As described above, even in the case of a pressure crystallizer with a small capacity, the liquid can be drained by controlling the actual drainage speed to a required low speed. Also, the pressure-resistant drainage container for drainage may have a smaller capacity than the high-pressure container, and can be made extremely small by the number of repetitions of the drainage, so that it is not necessary to make the entire apparatus large. ,
The size can be significantly reduced as compared with the case of the T-type drainage unit.

In the case of further pressing and pressing, the liquid can be drained by the same method as described above. Thereafter, products can be produced by the same method as in the case of the conventional apparatus.

The liquid discharging means of the pressure-resistant drainage container may be configured by connecting a flowing liquid pipe directly to the pressure-resistant draining container, and connecting a flowing liquid valve and a depressurizing nozzle to the pipe. And a flowing liquid pipe branched from the middle of the flow, a flowing liquid valve and a pressure reducing nozzle provided in the pipe. The latter is easier to produce a pressure-resistant drainage container than the former, and the production cost is lower,
The latter method is more preferable.

When a plurality of the separated liquid discharge means configured as described above are connected in parallel to the liquid discharge port, the number of liquid discharge repetitions per separated liquid discharge means is reduced, and the actual liquid discharge speed is kept constant. It becomes easy to maintain and discharge the required pattern.

(Example) Example 1 A pressure crystallization apparatus according to Example 1 is shown in FIG. The apparatus is a small-capacity pressure crystallization apparatus having a capacity of 70 ml, and a drain valve V _{3 is connected} to a liquid outlet (6) of a high-pressure vessel (9) by a drain pipe (10).
And a pressure-resistant drainage container (13) having a capacity of 70 ml and having a pressurizing mechanism (12), and a flow pipe (14) branched from the drain pipe (10) is provided. This is provided with a separated liquid discharging means (11) constituted by connecting a flowing liquid valve (15) and a depressurizing nozzle N, and the other points are the same as those shown in FIG.

Pressure crystallization was performed as described below using the above apparatus. First, a mixture of raw material (solution) was cooled in a preliminary crystallizer D yielding seed crystal, was injected into the crystallization chamber (8), the valve V _1, V
_{With 3} closed, the piston (4) was lowered to pressurize to 1500 atmospheres.

Then, immediately open the drain valve V _3, as well as lower the piston (4) while maintaining the pressure, a pressure mechanism (1
According to 2), the pressure in the pressure-resistant drainage vessel (13) is adjusted to a level slightly smaller than the pressure in the crystallization chamber (8), and the actual drainage speed is controlled to a required low speed. ) And valve
V ₃ liquid allowed to flow into the drainage container (13) from the crystallization chamber (8) by flowing liquid pipe (14) via a was drained.

Next, immediately before the drainage container is full of drainage, the flow valve (15) is opened, and the pressure in the drainage container (13) is slightly smaller than the pressure in the crystallization chamber (8). The liquid in the crystallization chamber (8) and the drainage vessel (13) are merged by adjusting the actual drainage speed to a required low speed, and the flow liquid valve (15) and the depressurizing nozzle N are adjusted. The liquid was discharged to the drainage tank T by the flowing liquid pipe (14).

During the drainage, just before the liquid in the drainage container (13) runs out, the flow valve (15) is opened, the pressure in the drainage container (13) is adjusted, and the actual drainage speed is adjusted to the required value. At a low speed, the drainage into the drainage container (13) is started, and thereafter, the drainage container (13)
The draining into the inside and the draining from the crystallization chamber (8) and the drainage container (13) as described above were repeated. At this time, the actual drainage speed could always be controlled to the required low speed to drain the liquid.

After the drainage, the remaining liquid was squeezed out by squeezing, and drained by the same method as described above. After discharging the residual liquid, the piston (4) was raised and the solid product on the lid (3) was taken out. After that, lower the cylindrical body (1) and cover (3)
Then, the process returns to the step of injecting the raw material, and the same steps are repeated to produce a product.

As a result, it was confirmed that the actual drainage speed could always be controlled to the required low speed for drainage, and that the product yield was as excellent as in the case of the T-type drainage means described above. The entire apparatus could be made more compact than in the case of T-type drainage means.

As shown in FIG. 2, the separated liquid discharging means (11) connects the flowing liquid pipe (14) to the pressure-resistant liquid discharging container (13) connected to the liquid discharging port (6) of the high-pressure container (9). It can also be constructed by directly connecting, connecting the flow valve (15) and the decompression nozzle N to the pipe (14),
The same effects as above can be obtained.

Example 2 FIG. 3 shows a pressure crystallization apparatus according to Example 2. The apparatus includes the same separated liquid discharging means (16) as in the first embodiment,
Two liquid outlets (10) are connected in parallel, and the other points are the same as in the first embodiment. Using this apparatus, pressure crystallization was performed in the same manner as in Example 1 except for the following points. That is, at the time of drainage, the two draining means (16) were alternately operated to drain the liquid. as a result,
Compared with Example 1, it was easier to maintain the actual drainage speed constant. The product yield was as good as in Example 1.

(Effect of the Invention) According to the pressure crystallizer according to the invention, even in the case of a pressure crystallizer having a small capacity, the actual drainage speed can be controlled at a low speed.
It is not necessary to make the whole apparatus large in order to control the actual drainage speed to a low speed, and the whole apparatus can be made more compact than in the case of the T-type drainage means.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an outline of a pressure crystallization apparatus according to Embodiment 1, FIG. 2 is a side sectional view showing an example of a separated liquid discharging means of the pressure crystallization apparatus according to the present invention, and FIG. FIG. 4 is a side sectional view showing an outline of a pressure crystallization apparatus according to Embodiment 2, and FIG. 4 is a side sectional view showing a typical example of a conventional pressure apparatus. (1) ... pressure-resistant cylinder, (2) ... tubular filter (3) ... lid, (4) ... piston (5) ... material supply pipe, (6) ... drain port ( 7)… pusher, (8) crystallization chamber (9)… high-pressure vessel, (10)… drain pipe (11)… separation liquid discharge means, (12)… pressurizing mechanism (13)… ... pressure-resistant drainage container, (14) ... flow tube (15) ... flow valve, P ... raw material supply pump D ... preliminary crystallization can, N ... pressure reducing nozzle T ... drain tank V ₁ …… Valve V ₂ , V ₃ …… Drain valve

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI B01D 9/02 618 B01D 9/02 618B (72) Inventor Shingo Yoshida 2-3-1 Shinohara Akiminoyamacho, Nada-ku, Kobe-shi, Hyogo (72) Inventor Shunsuke Takada 2-3-1 Shinohara Amo Noyama-cho, Nada-ku, Kobe City, Hyogo Prefecture (56) References JP-A-2-265601 (JP, A) JP-A-2-214505 (JP, A) JP-A Sho54 -53362 (JP, A) JP-A-61-149203 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01D 9/02

Claims (3)

(57) [Claims] 1. A high-pressure container, means for supplying a mixture into the container, means for pressurizing the mixture in the container, a solid-liquid separation mechanism for the solid-liquid mixture in the container, and discharge of the separated liquid from the container In a pressure crystallization apparatus having a separation liquid discharge means whose speed can be controlled, a liquid discharge port of a high-pressure container and a pressure-resistant drainage container having a pressurizing mechanism are connected by a drainage pipe, and the drainage container A pressure crystallization apparatus, wherein a liquid discharging means is provided to form the separated liquid discharging means. 2. The liquid discharge means of the pressure-resistant drain container comprises a flow pipe branched from the middle of the drain pipe, a flow valve and a pressure reducing nozzle provided in the pipe. The pressure crystallization apparatus according to the above. 3. The pressure crystallization apparatus according to claim 1, wherein a plurality of said separated liquid discharging means are connected in parallel to said liquid discharging port.