JP7035470B2 - Slurry extraction method from reaction equipment and autoclave - Google Patents

Description

The present invention relates to a reaction facility including an autoclave, and more particularly, a reaction facility including an autoclave that causes a reaction under high temperature and high pressure conditions to generate a slurry containing a solid substance, and a slurry from the autoclave. Regarding the extraction method.

Conventionally, a slurry containing unreacted substances and reaction products in a high-temperature / high-pressure reaction vessel (hereinafter referred to as “autoclave”) is operated at high temperature and high pressure. Was extracted from. Specifically, FIG. 2 shows an example of an equipment configuration including an autoclave and a flash vessel, and shows a flow of extracting slurry from the autoclave to the flash vessel.

In FIG. 2, reference numeral 51 indicates an autoclave, reference numeral 52 indicates a flash vessel, reference numeral 53 indicates a flush valve, and reference numeral 54 indicates a heat exchanger. Although FIG. 2 shows an example in which the flush valve 53 is provided at the top of the flush vessel 52, the flush valve 53 is provided in a pipe 55 that connects the autoclave 51 and the flush vessel 52 and transfers the slurry. There is also.

In such equipment, the flush valve 53 provided between the autoclave 51 and the flush vessel 52 and the pipe 55 on the downstream side of the autoclave 51 are easily thinned due to wear due to the extraction of the slurry, and the frequency of replacement is high. rice field.

This is because the high-temperature and high-pressure water in the autoclave is rapidly decompressed when passing through the flush valve to become flush steam, which passes through devices such as the flush valve and piping at a high speed. In addition, if the flash vapor contains unreacted substances or reaction products that are solid substances, thinning due to wear is more likely to occur, especially when the hardness of these solid substances is high, and the apparatus becomes more prone to wall thinning. It led to damage. In addition, damage to the equipment has been a factor leading to increased operating costs.

In the equipment shown in FIG. 2, the flash steam generated in the flash vessel 52 is recovered via the pipe 56 and supplied to the heat exchanger 54 to be used as a heat source for preheating the raw material to be supplied to the autoclave 52. It is possible to do.

The Applicant has provided a pressurized storage container (hereinafter referred to as "receiving vessel") connected to the slurry take-out port (discharge port) of the autoclave in order to improve problems such as wear of the device due to slurry extraction. We propose a method in which the slurry from the autoclave is transferred to the receiving vessel, and then the internal pressure of the receiving vessel loaded with the slurry is gradually reduced, and then the slurry is extracted (prior application: Japanese Patent Application No. 2016). -107131).

FIG. 3 shows an example of equipment configuration to which the method according to the prior application is applied. Specifically, as shown in FIG. 3, a receiving vessel 62 (62A, 62B) having a pressure slightly lower than the internal force of the autoclave 61 is provided on the downstream side of the autoclave 61 via the pipe 63 instead of the flush vessel. .. Then, the slurry from the autoclave 61 is transferred to the receiving vessel 62, and then the internal pressure of the receiving vessel 62 is gradually reduced, and then the slurry is taken out. According to such a method, it is possible to reduce the wear and the like of the apparatus due to the conventional flash steam and the solid matter accompanying the flash steam. Note that FIG. 3 shows an example in which two (two series) receiving vessels 62A and 62B are provided, and the two series are sequentially switched to continuously extract the slurry from the autoclave 61.

However, in this method, since the receiving vessel 62 (62A, 62B) is provided instead of the flush vessel, the heat recovery by the flash steam, which was possible when the conventional flash vessel was configured, cannot be performed. , Was supposed to lead to energy loss in the equipment.

Japanese Patent Application No. 2016-107131

The present invention has been proposed in view of such circumstances, and when the slurry generated from an autoclave that reacts under high temperature and high pressure conditions is extracted, the equipment constituting the reaction facility may be worn or damaged. It is an object of the present invention to provide a method capable of effectively recovering the thermal energy generated in the autoclave while reducing the amount.

The present inventor has made extensive studies to solve the above-mentioned problems. As a result, a receiving vessel is provided on the downstream side of the autoclave, and a flush vessel is further provided on the downstream side thereof to form a reaction facility. The slurry containing the solid content generated in the autoclave is transferred to the receiving vessel, and then the supernatant liquid is transferred. We have found that by transferring a part of the vessel to a flash vessel, it is possible to reduce the occurrence of wear of the device and effectively recover the thermal energy, and have completed the present invention.

(1) The first invention of the present invention is a reaction facility provided with an autoclave that reacts under high temperature and high pressure conditions, and the pressure is equal to or slightly reduced to the internal pressure of the autoclave, and the autoclave is decompressed. It is provided with a receiving vessel for introducing a slurry containing the solid content generated in the above step, and a flush vessel provided with a flush valve for introducing only the supernatant liquid of the slurry introduced into the receiving vessel while rapidly decompressing it. , Reaction equipment.

(2) In the second invention of the present invention, in the first invention, the flash vessel is provided with a steam discharge port for discharging the flash steam generated by the rapid decompression when the supernatant liquid is introduced. , A reaction facility in which the flash steam discharged from the steam discharge port is recovered.

(3) In the third aspect of the present invention, in the second invention, the flash vessel is connected to the heat exchanger via the steam discharge port, and the flash steam discharged from the steam discharge port is discharged. It is a reaction facility that is recovered and heat exchanged by the heat exchanger.

(4) In the fourth aspect of the present invention, in any one of the first to third inventions, the internal pressure of the receiving vessel is 0.2 MPa or more and 1.0 MPa or less than the internal pressure of the autoclave. It is a reaction facility that introduces a slurry containing the solid content from the autoclave while keeping it low in the range.

(5) In the fifth aspect of the present invention, in the fourth aspect, a gas charging pipe for charging an inert gas or compressed air is connected to the receiving vessel, and the gas charging pipe is connected. It is a reaction facility in which the internal pressure is regulated by the charging of inert gas or compressed air through it.

(6) The sixth invention of the present invention is a slurry extraction method for extracting a slurry generated by an autoclave that reacts under high temperature and high pressure conditions, and obtains a slurry containing a solid content generated by the autoclave. Transfer to a receiving vessel that is equal to or slightly depressurized to the pressure inside the autoclave, and then only the supernatant liquid of the slurry introduced into the receiving vessel is transferred to the flush vessel provided with a flush valve. The slurry was transferred while being rapidly depressurized, and in the receiving vessel, the internal pressure was gradually reduced, and then the slurry containing the solid content remaining in the receiving vessel was extracted, and in the flash vessel, the introduced supernatant liquid was used. This is a method for extracting a slurry from an autoclave, which comprises extracting and recovering the flash vapor generated in the flush vessel.

(7) In the sixth aspect of the present invention, the seventh aspect of the present invention separates the slurry introduced into the receiving vessel by allowing the slurry to stand still and naturally precipitating the solid content contained in the slurry. This is a method for extracting a slurry from an autoclave, in which only the supernatant liquid is transferred to the flash vessel.

According to the present invention, when extracting a slurry generated from an autoclave that reacts under high temperature and high pressure conditions, the occurrence of wear and damage to the equipment constituting the reaction facility is reduced, and the heat energy generated in the autoclave is effectively used. Can be collected in.

It is a block diagram which shows an example of the structure of the reaction equipment which includes an autoclave, and is the figure for demonstrating the flow of transfer of a slurry from an autoclave. It is a block diagram which shows the structure of the reaction equipment provided with the conventional autoclave, and is the figure of the reaction equipment which connected the flash vessel to the downstream side continuous with the autoclave. It is a block diagram which shows the structure of the reaction equipment which connected the receiving vessel without providing the flush vessel on the downstream side of the autoclave.

Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention. Further, in the present specification, the notation "X to Y" (X and Y are arbitrary numerical values) means "X or more and Y or less".

≪1. Configuration of reaction equipment equipped with autoclave ≫
The reaction equipment according to the present embodiment is a reaction equipment provided with an autoclave that reacts under high temperature and high pressure conditions. Specifically, this reaction facility includes an autoclave that produces a slurry containing a reaction product that is a solid substance from a raw material under high temperature and high pressure conditions, and a device for extracting the produced slurry (post-reaction slurry) from the autoclave. It is composed of.

FIG. 1 is a diagram showing an example of the configuration of the reaction equipment according to the present embodiment. As shown in FIG. 1, the reaction equipment 1 is introduced into the autoclave 2 that reacts under high temperature and high pressure conditions, the receiving vessels 3A and 3B that introduce the slurry generated in the autoclave 2, and the receiving vessels 3A and 3B. A flash vessel 4 for introducing a part of the slurry is provided. Further, the reaction facility 1 includes a heat exchanger 5 that recovers the generated energy and exchanges heat with a heat source for preheating the raw material to be supplied to the autoclave 2.

As described above, in the reaction facility 1, the receiving vessels 3A and 3B are provided on the downstream side of the autoclave 2, and the flush vessel 4 is further provided on the downstream side thereof.

[Autoclave]
The autoclave 2 is a pressurized reaction vessel, to which a reaction raw material is supplied, and the reaction is carried out under high temperature and high pressure conditions as described above. In the autoclave 2, a slurry containing a reaction product or an unreacted product which is a solid substance is generated.

The reaction conditions in the autoclave 2 are not particularly limited, but can be, for example, a high temperature of about 150 ° C. to 300 ° C. and a high pressure of about 1 MPa to 5 MPa. Further, the specific reaction carried out in the autoclave 2 is not particularly limited, and any reaction that produces a slurry containing a solid substance by the reaction under high temperature and high pressure conditions can be preferably applied. For example, a slurry containing nickel powder by reducing nickel ions in the solution to nickel at a temperature of about 150 ° C. to 250 ° C. and a pressure of about 2.5 MPa to 3.5 MPa using a nickel sulfate ammine complex solution as a raw material. Can be mentioned as a reaction that causes the above. It can also be applied to a high-temperature pressurized acid leaching reaction in a hydrometallurgical process of nickel oxide ore. Specifically, at a temperature of about 230 ° C. to 270 ° C. and a pressure of about 3 MPa to 5 MPa, valuable metals such as nickel are leached out while adding sulfuric acid from the ore slurry as a raw material, and the leached liquid and impurities such as iron are formed. It can be applied to a reaction that produces a leachate slurry containing a leachate residue.

The autoclave 2 is not particularly limited, but is provided with a stirring device 21 so that the raw materials supplied to the autoclave 2 can be stirred to improve the reaction efficiency. Further, the autoclave 2 is provided with a level meter 22 for measuring the level of the raw material charged therein and the slurry generated by the reaction. For example, the level meter 22 monitors the liquid level of the slurry. , It is possible to control the slurry transfer to the receiving vessel 3, which will be described later.

Here, since the slurry after the reaction produced in the autoclave 2 is produced under high temperature and high pressure reaction conditions, it has a high temperature and a high pressure. Conventionally, when extracting a slurry generated by an autoclave, a flash vessel is connected to the autoclave, and the high-temperature and high-pressure slurry is introduced into the flash vessel while being depressurized to atmospheric pressure, and the extraction operation is performed. However, in such a conventional method, the slurry extracted to the flush vessel is discharged from the autoclave at an extremely high flow velocity, and therefore, the valve (flash valve) provided in the flush vessel due to contact with the slurry. ) And the inside of the pipe was prone to wear and damage. In particular, the main cause of the wear and the like is the solid content contained in the slurry, and the greater the hardness of the solid content, the greater the degree of wear and the like, which reduces the durability of the apparatus.

Therefore, in the reaction facility 1 according to the present embodiment, the autoclave 2 is connected to the receiving vessel 3 via the pipe 11, and the slurry containing the solid content generated in the autoclave 2 is transferred to the receiving vessel 3. I am doing it.

[Receiving Vessel]
The receiving vessel 3 is a storage container into which a slurry containing a solid content produced by the autoclave 2 is introduced. The autoclave 2 and the receiving vessel 3 are connected to each other via a pipe 11, and the slurry containing a solid content is transferred to the receiving vessel 3 through the pipe 11.

The internal pressure of the receiving vessel 3 is adjusted and maintained at a pressure equal to or slightly reduced to the internal pressure of the autoclave 2 at least during the transfer of the slurry. As described above, in the reaction facility 1, the slurry containing the solid content generated in the autoclave 2 is not depressurized to the atmospheric pressure at once, but is once adjusted to a pressure slightly depressurized from the internal pressure of the autoclave 2. It is transferred to the receiving vessel 3 which has been used. From this, it is possible to prevent the slurry from moving at high speed with rapid decompression (rapid decompression), and to prevent wear and damage of the apparatus.

Here, in the reaction facility 1 of FIG. 1, an example including two (two series) receiving vessels 3 (3A, 3B) is shown. The number of receiving vessels 3 installed is not limited to this. The receiving vessel 3 may be provided with only one (1 series), but as shown in FIG. 1, by providing a plurality of series such as 2 series, the slurry from the autoclave 2 can be provided. It can be sequentially and continuously transferred to the receiving vessels 3A and 3B of the series.

Further, in the reaction facility 1 provided with two series of receiving vessels 3A and 3B, the pipe 11 for transferring the slurry containing the solid content to the receiving vessels 3A and 3B is a branch pipe, and the receiving pipe 3A is provided by the branched pipe 11a. The slurry is transferred to the receiving vessel 3B by the branched pipe 11b.

In the pipe 11 (11a, 11b) which is a branch pipe, valves 12, 13 and 14 are provided before and after the branch point to control ON / OFF of the slurry supply.

As described above, in the receiving vessels 3A and 3B, the internal pressure is adjusted to a pressure equal to or slightly reduced to the internal pressure of the autoclave 2. Further, more preferably, the pressure is slightly reduced by a pressure difference in the range of 0.2 MPa or more and 1.0 MPa or less. That is, in a state where the internal pressure of the receiving vessels 3A and 3B is kept lower than the internal pressure of the autoclave 2 in the range of preferably 0.2 MPa or more and 1.0 MPa, the slurry after the reaction is removed from the autoclave 2 in the receiving vessel 3A. Transfer to 3B. As a result, the transfer of the slurry proceeds smoothly, and on the other hand, since the pressure difference is slight, it is possible to prevent the speed of the slurry from increasing.

If the pressure difference between the autoclave 2 and the receiving vessels 3A and 3B is less than 0.2 MPa, it becomes difficult to take out (transfer) the slurry containing the solid content, and the work efficiency may decrease. On the other hand, if the pressure difference exceeds 1.0 MPa, the discharge rate of the slurry from the autoclave 2 becomes too high, and there is a possibility that the occurrence of wear or damage in the apparatus cannot be effectively suppressed.

In the receiving vessels 3A and 3B, a gas charging pipe 31 for charging an inert gas such as nitrogen gas or argon gas or compressed air is connected. In the receiving vessels 3A and 3B, the internal pressure is adjusted by charging inert gas or compressed air through the gas charging pipe 31. Specifically, as described above, the internal pressure is adjusted to a pressure equal to or slightly reduced to the internal pressure of the autoclave 2.

The gas charging pipe 31 is provided with a valve 32 capable of adjusting the flow rate of the supplied gas, so that the internal pressures of the receiving vessels 3A and 3B can be appropriately adjusted.

In the receiving vessels 3A and 3B, the slurry containing the solid content introduced from the autoclave 2 is discharged and extracted through the slurry discharge pipe 15 connected to the slurry discharge port 33. The slurry extracted from the receiving vessels 3A and 3B is the amount obtained by removing a part of the supernatant liquid of the slurry transferred to the flash vessel 4, which will be described later. Further, the slurry extracted contains almost all the solid content produced by the reaction in the autoclave 2. Further, the amount of slurry extracted from the receiving vessels 3A and 3B can be controlled by adjusting the valve 30 provided in the slurry discharge pipe 15.

When extracting the slurry from the receiving vessels 3A and 3B, the internal pressure of the receiving vessels 3A and 3B into which the slurry is introduced is gradually reduced, and the internal pressure is set to atmospheric pressure or less. As a method of reducing the internal pressure when extracting the slurry, for example, the temperature of the slurry existing inside is cooled to 100 ° C. or lower by surrounding the cooling jacket 3j in the receiving vessels 3A and 3B. Can be done. Further, since the receiving vessels 3A and 3B are in a high pressure state due to the charging of inert gas or compressed air through the gas charging pipe 31, gas is discharged from the gas discharging pipe 34 that discharges the internal gas. By allowing the gas to decrease, the internal pressure is reduced. The gas discharge from the gas discharge pipe 34 can be controlled by adjusting the opening and closing of the valve 32.

The receiving vessels 3A and 3B are provided with a pressure gauge 38, and the internal pressure can be measured and monitored so as to meet a predetermined pressure condition. Further, the receiving vessels 3A and 3B are provided with a level meter 39 for measuring the liquid level of the slurry, and the amount of slurry introduced from the autoclave 2 into the receiving vessels 3A and 3B and the slurry removed from the receiving vessels 3A and 3B. It is possible to monitor the amount of output, etc.

The reaction facility 1 according to the present embodiment is characterized in that the receiving vessels 3A and 3B are connected to the flash vessel 4 via the pipe 36. As will be described in detail later, in the reaction facility 1, a slurry containing a solid content is introduced into the receiving vessels 3A and 3B, and the slurry is allowed to stand to allow the solid content to settle naturally, and then only the supernatant liquid in the slurry is used. It is transferred to the flash vessel 4.

[Flash vessel]
The flush vessel 4 is a container provided with a flush valve 41 at the introduction port, and the flush valve 41 introduces the solution into the inside while rapidly decompressing (rapidly decompressing) the solution. Specifically, in the flash vessel 4, a part of the supernatant liquid of the slurry transferred through the pipe 36 is introduced into the inside while being rapidly decompressed to a pressure of about atmospheric pressure.

At this time, the supernatant liquid is instantly decompressed (rapidly decompressed) when passing through the flush valve 41, so that the supernatant vapor becomes 100 ° C. or higher when introduced into the container.

Here, the solution introduced into the flash vessel 4 is a solution transferred from the receiving vessels 3A and 3B maintained in a high pressure state equal to or slightly depressurized from that of the autoclave 2, and is in a high temperature and high pressure state. Is. However, the solution is only the supernatant (supernatant) of the slurry stored in the receiving vessels 3A and 3B, and is a solution containing almost no solid content. Therefore, at the time of introduction into the flush vessel 4, the supernatant liquid is rapidly decompressed by the flush valve 41 and flows at high speed, but since it is a solution containing no solid content, the device such as the flush valve 41 is worn out. Damage and the like can be reduced.

On the other hand, as described above, the supernatant liquid that is rapidly decompressed by the flush valve 41 and introduced into the flush vessel 4 becomes flush vapor, so that the heat possessed by the flush vapor can be effectively recovered as a heat source. ..

Specifically, the flash vessel 4 is provided with a steam discharge port 42 near the top, for example, and can discharge the flash steam inside the flash vessel 4. In the reaction facility 1, by recovering the flash steam discharged from the steam discharge port 42, the heat possessed by the flash steam can be effectively recovered as various heat sources. As a result, energy loss can be effectively reduced.

The flash vessel 4 is provided with, for example, a slurry discharge port 43 at the bottom, so that the slurry (only the supernatant liquid) stored in the flash vessel 4 can be discharged and extracted. A slurry discharge pipe 15 is connected to the slurry discharge port 43, and the slurry is taken out through the slurry discharge pipe 15. Further, the amount of slurry extracted from the flush vessel 4 can be controlled by adjusting the valve 40 provided in the slurry discharge pipe 15.

Further, the flash vessel 4 is provided with a level meter 44 for measuring the liquid level of the slurry, and the amount of the slurry introduced from the receiving vessels 3A and 3B (only the supernatant liquid) and the extraction of the slurry from the flash vessel 4 are provided. The amount etc. can be monitored.

[Heat exchanger]
The heat exchanger 5 is provided, for example, in the middle of the raw material supply pipe for supplying the raw material to the autoclave 2. The heat exchanger 5 is connected to the flash vessel 4 via the steam discharge port 42, recovers the flash steam discharged from the steam discharge port 42 through the steam pipe 45, and exchanges the flash steam for heat. ..

The configuration of the heat exchanger 5 is not particularly limited as long as it can effectively exchange the flash steam for heat, and a known device can be used.

According to the reaction facility 1 having the above configuration, the receiving vessel 3 (3A, 3B) is provided on the downstream side of the autoclave 2, and the flash vessel 4 is further provided on the downstream side thereof, thereby as in the conventional facility. It is possible to reduce the occurrence of wear and damage to devices such as flash valves and pipes. Further, according to the reaction facility 1, since the flash vessel 4 is provided at a predetermined position and configured to generate the flash steam, the heat derived from the flash steam can be effectively recovered. As a reaction facility, energy loss can be prevented.

≪2. How to extract the slurry from the autoclave ≫
Next, in the reaction equipment 1 shown in FIG. 1, a method of extracting the slurry containing the solid content generated in the autoclave 2 from the autoclave 2 will be specifically described.

[About the configuration of reaction equipment]
As described above, the reaction facility 1 is a facility provided with an autoclave 2 that reacts under high temperature and high pressure conditions, and is equal to or slightly decompressed with the internal pressure of the autoclave 2 and is used in the autoclave 2. A receiving vessel 3 (3A, 3B) for introducing a slurry containing the generated solid content and a flush valve 41 are provided, and only the supernatant liquid of the slurry introduced in the receiving vessel 3 is introduced while being rapidly decompressed. It is equipped with a vessel 4. That is, the reaction facility 1 is configured by providing a receiving vessel 3 on the downstream side of the autoclave 2 and further providing a flash vessel 4 on the downstream side thereof.

As shown in FIG. 1, the reaction facility 1 includes two series of receiving vessels 3A and 3B, and the valves 12 and 13 provided in the pipes 11a and 11b connecting the autoclave 2 and the receiving vessels 3A and 3B. By adjusting, and 14, the transfer destination of the slurry from the autoclave 2 is switched, and the slurry is continuously transferred.

[About extracting slurry from the autoclave]
(Adjustment of internal pressure of receiving vessel)
First, in the reaction facility 1, when extracting the slurry containing the solid content generated in the autoclave 2, as a preliminary work, the pressure inside the receiving vessels 3A and 3B continuously connected to the downstream side of the autoclave 2 is performed. Is adjusted to the same pressure as the pressure inside the autoclave 2 or slightly reduced.

Specifically, the inert gas or compressed air is charged into the receiving vessels 3A and 3B via the gas charging pipes 31 connected to the receiving vessels 3A and 3B. The charging of the inert gas or the like through the gas charging pipe 31 can be controlled by opening and closing the valves 32a and 32b provided in the gas charging pipe 31. Further, the valves 32a and 32b can be control valves that can control the amount of gas charged. The valve 32a is a valve that controls gas charging to the receiving vessel 3A, and the valve 32b is a valve that controls gas charging to the receiving vessel 3B. For example, the receiving valve 3A is opened with the valve 32a open. When the gas is charged into the receiving vessel 3B, the valve 32b is closed and the gas charging to the receiving vessel 3B is stopped.

The receiving vessel 3A and 3B are provided with a pressure gauge 38 capable of measuring the internal pressure, and the internal pressure is continuously measured and monitored by the pressure gauge 38 through the gas charging pipe 31. Charge with inert gas, etc.

By such an operation, as a preparatory work, the internal pressure in the receiving vessels 3A and 3B is brought into a state of being equal to or slightly reduced to the internal pressure of the autoclave 2. More preferably, the internal pressure in the receiving vessels 3A and 3B is maintained lower than the internal pressure of the autoclave in the range of 0.2 MPa or more and 1.0 MPa or less.

(Transfer of slurry from autoclave to receiving vessel)
Next, the slurry generated by the reaction under high temperature and high pressure in the autoclave 2 is transferred to the receiving vessels 3A and 3B whose internal pressure is adjusted. Here, the slurry transferred from the autoclave 2 to the receiving vessels 3A and 3B is a slurry containing a solid content composed of reaction products and unreacted substances generated by the reaction in the autoclave 2, and is in a high temperature and high pressure state. It is a slurry in.

To start the transfer of the slurry, after confirming that the liquid level of the slurry in the autoclave 2 has reached a predetermined level, the valve 12 and the valve 13 or the valve 14 provided in the pipe 11 are opened, and the pipe 11 is opened. Transfer to the receiving vessel 3A, 3B via. The liquid level of the slurry in the autoclave 2 can be adjusted by using the level meter 22 provided in the autoclave 2.

The transfer of the slurry from the autoclave 2 to the receiving vessels 3A and 3B is due to the pressure difference because the internal pressure of the receiving vessels 3A and 3B is maintained at a pressure preferably slightly lower than the internal pressure of the autoclave 2. It is done naturally. It should be noted that a pressure pump or the like may be provided in the pipe 11 so that the pipe 11 can be transferred by the pump pressure.

When two series of receiving vessels 3A and 3B are provided as in the reaction equipment 1 shown in FIG. 1, the receiving vessels 3A and 3B to which the slurry is transferred from the autoclave 2 are sequentially switched. For example, the slurry is transferred to the receiving vessel 3A via the pipe 11a, and the slurry is transferred to the receiving vessel 3B via the pipe 11b, and the valves 13 and 14 provided in the respective pipes 11a and 11b are transferred. By controlling the opening and closing of the receiving vessel 3, the series of the receiving vessel 3 at the transfer destination is switched.

Then, for example, the slurry is transferred from the autoclave 2 to the receiving vessel 3A (at this time, the valve 13 is in the open state and the valve 14 is in the closed state), and the slurry liquid level in the receiving vessel 3A is predetermined. When the level is reached, the valve 13 is closed to stop the slurry transfer to the receiving vessel 3A. Then, by closing the valve 13 and opening the valve 14 at the same time, the operation of transferring the slurry from the autoclave 2 is switched to the receiving vessel 3B. In this way, the transfer destination of the slurry is sequentially switched between the receiving vessel 3A and the receiving vessel 3B so that the slurry is continuously transferred.

The liquid level of the slurry in the receiving vessels 3A and 3B can be adjusted by using a level total 39 provided in each of the receiving vessels 3A and 3B.

(Transfer of slurry supernatant to flash vessel)
When the slurry containing the solid content is transferred from the autoclave 2 to, for example, the receiving vessel 3A, the slurry introduced into the receiving vessel 3A is allowed to stand inside to allow the solid content contained in the slurry to settle naturally. .. As a result, in the slurry inside the receiving vessel 3A, the solid content is naturally separated from the lower layer and the supernatant liquid is naturally separated from the upper layer.

Then, after a slurry in which the solid content and the supernatant liquid are separated is obtained, only the supernatant liquid in the slurry is transferred to the flush vessel 4 provided with the flush valve 41 at the introduction port. Specifically, only the supernatant liquid is transferred by opening the valve 37a on the pipe 36 via the pipe 36 connecting the receiving vessel 3A and the flush vessel 4 (at this time, the valve 37b is closed). Is in a state). The supernatant liquid to be transferred to the flush vessel 4 is not all the supernatant liquid in the slurry in the receiving vessel 3A, but a part thereof.

The slurry transferred to the receiving vessel 3A, which is at a pressure equal to or slightly lower than the internal pressure of the autoclave 2, is in a high temperature and high pressure state, and remains in that state even after the natural separation of the solid content and the supernatant liquid. be. When only the supernatant liquid of the slurry is transferred from the receiving vessel 3A to the flush vessel 4 via the pipe 36, the supernatant liquid is rapidly decompressed (rapid decompression) when passing through the flush valve 41 provided in the flush vessel 4. Will be done. Then, when introduced into the flash vessel 4, the supernatant liquid becomes flash vapor of 100 ° C. or higher.

Here, the supernatant liquid to be transferred to the flash vessel 4 is the solution content of the slurry excluding the solid content. Therefore, even when the high-temperature and high-pressure supernatant liquid is transferred from the receiving vessel 3A to the flush vessel 4 and rapidly decompressed, the devices such as the flush valve, which are derived from the solid content in the slurry as in the conventional case, are not worn or damaged. It can be suppressed. In particular, in the slurry produced by the autoclave 2, even if a solid content having a relatively high hardness is generated as a reaction product, the solid content in the slurry is not transferred to the flush vessel 4, so that the flush valve 41 or the like has a device such as a flush valve 41. Wear and the like can be effectively reduced.

Further, by transferring only the supernatant liquid to the flush vessel 4 in this way, the flush vapor is generated via the flush valve 41, so that the flush vapor can be recovered as a heat source. That is, according to such a method of extracting the slurry using the reaction equipment 1, it is possible to efficiently generate a heat source in the reaction equipment 1, and it is possible to prevent energy loss by recovering the generated heat. Can be done.

In the reaction facility 1, the flash steam from the steam discharge port 42 of the flash vessel 4 is recovered by the steam pipe 45, and heat is exchanged by the heat exchanger 5 connected via the steam pipe 45. ing. The heat exchanged based on the flash steam in the heat exchanger 5 is used as a heat source to preheat the raw material supplied to the autoclave 2.

By sequentially and alternately transferring the supernatant liquid from the two series of receiving vessels 3A and 3B to the flash vessel 4, heat recovery can be performed without waste. Specifically, by opening the valve 37a on the pipe 36 and closing the valve 37b, the supernatant liquid is transferred from the receiving vessel 3A to the flush vessel 4 and transferred to the flush vessel 4 as described above. To recover heat. Then, after the supernatant liquid is transferred from the receiving vessel 3A, the valve 37b on the pipe 36 is closed and the valve 37b is opened at the same time, so that the transfer source of the supernatant liquid to the flush vessel 4 is received. Instead of the vessel 3B, the transfer of the supernatant liquid from the receiving vessel 3B to the flush vessel 4 is started, and heat is recovered.

The transfer of the supernatant liquid from the receiving vessel 3A to the flush vessel 4 is stopped when it is detected that the liquid level of the slurry in the receiving vessel 3A is equal to or lower than a predetermined set value. The transfer can be stopped by closing the valve 37 provided on the pipe 36. The liquid level of the slurry in the receiving vessel 3A can be determined by monitoring the measured value by the level meter 39.

When transferring the supernatant liquid from the receiving vessel 3A to the flush vessel 4, the internal pressure of the receiving vessel 3A may not decrease even if the level of the slurry in the receiving vessel 3A decreases due to the transfer. preferable. That is, it is preferable to maintain the internal pressure of the receiving vessel 3A at a pressure equal to or slightly lower than the internal pressure of the autoclave 2 even when the supernatant liquid is transferred to the flush vessel 4. This makes it possible to more efficiently recover the heat generated through the flush valve 41 by transferring only the supernatant liquid from the receiving vessel 3A to the flush vessel 4.

The internal pressure of the receiving vessel 3A is adjusted by continuously monitoring the pressure value measured by the pressure gauge 38, and appropriately charging the receiving vessel 3A with an inert gas or compressed air via the gas charging pipe 31. It can be done by entering. Specifically, when the supernatant liquid from the receiving vessel 3A is transferred to the flush vessel 4, the valve 32a provided in the gas charging pipe 31 is adjusted while monitoring the pressure value measured by the pressure gauge 38. (At this time, the valve 32b is closed), and the internal pressure of the receiving vessel 3A is adjusted by controlling the charging of inert gas and compressed air.

(Slurry extraction)
After the transfer of the supernatant liquid to the flash vessel 4 is completed, the residual slurry is extracted from the receiving vessel 3A. Specifically, the temperature of the slurry containing the solid content stored inside is lowered to 100 ° C. or lower by cooling with the cooling jacket 3j provided around the container in the receiving vessel 3A, whereby the receiving vessel 3A is lowered. Reduces the internal pressure of the. Further, the internal pressure is lowered by appropriately discharging the gas existing inside through the gas discharge pipe 34 connected to the receiving vessel 3A. The gas discharge from the receiving vessel 3A via the gas discharge pipe 34 can be controlled by adjusting the opening and closing of the valve 35a. When the slurry is taken out from the receiving vessel 3B after the slurry is taken out from the receiving vessel 3A, the opening / closing of the valve 35b is adjusted in the same manner to control the gas discharge through the gas discharge pipe 34. ..

Then, after the internal pressure of the receiving vessel 3A is reduced to a pressure equal to or lower than the atmospheric pressure, the slurry is discharged and extracted from the slurry discharge port 33 provided at the bottom of the receiving vessel 3A. The slurry discharged from the receiving vessel 3A can be discharged to the outside of the reaction facility 1 via the slurry discharge pipe 15. Further, by adjusting the valve 30a provided on the slurry discharge pipe 15, it is possible to control the discharge and extraction of the slurry from the receiving vessel 3A.

After the extraction of the slurry from the receiving vessel 3A is completed, the operation of extracting the slurry from the receiving vessel 3B is subsequently performed. Even when the slurry is extracted from the receiving vessel 3B, the pressure inside the receiving vessel 3A is reduced by lowering the slurry temperature to 100 ° C. or lower by cooling with the cooling jacket 3j. Further, the internal pressure is lowered by appropriately adjusting the opening and closing of the valve 35b to control the discharge of the gas existing inside via the gas discharge pipe 34 connected to the receiving vessel 3B. Then, after the internal pressure of the receiving vessel 3B is reduced to a pressure equal to or lower than the atmospheric pressure, the slurry is discharged and extracted from the slurry discharge port 33 provided at the bottom. At this time, by adjusting the valve 30b provided on the slurry discharge pipe 15, it is possible to control the discharge and extraction of the slurry from the receiving vessel 3B.

Further, since the slurry (supernatant) introduced from the receiving vessel 3A is also stored in the flush vessel 4, the flash vapor is effectively recovered and then the internal pressure is lowered to reduce the pressure to below atmospheric pressure. After that, the slurry is discharged from the slurry discharge port 43 and is taken out. The slurry discharged from the flash vessel 4 can be discharged to the outside of the reaction facility 1 via the slurry discharge pipe 15. Further, by adjusting the valve 40 provided on the slurry discharge pipe 15, it is possible to control the discharge and extraction of the slurry from the flush vessel 4.

1 Reaction equipment 2 Autoclave 3,3A, 3B Receiving vessel 4 Flash vessel 5 Heat exchanger 11,11a, 11b piping 12,13,14 Valve 15 Slurry discharge piping 21 Stirrer 22 Level meter 30a, 30b Valve 31 Gas charging piping 32a, 32b Valve 33 Slurry discharge port 34 Gas discharge pipe 35a, 35b Valve 36 Piping 37a, 37b Valve 38 Pressure gauge 39 Level meter 40 Valve 41 Flash valve 42 Steam discharge port 43 Slurry discharge port 44 Level meter 45 Steam piping

Claims (6)

A reaction facility equipped with an autoclave that reacts under high temperature and high pressure conditions.
A receiving vessel that introduces a slurry containing the solid content generated in the autoclave while maintaining the pressure equal to or lower than the internal pressure of the autoclave or in the range of 0.2 MPa or more and 1.0 MPa or less than the internal pressure of the autoclave. When,
A reaction facility provided with a flush valve and provided with a flush vessel for introducing only the supernatant liquid of the slurry introduced into the receiving vessel while rapidly decompressing it. The flash vessel is provided with a steam discharge port for discharging the flash steam generated by the rapid decompression when the supernatant liquid is introduced.
The reaction facility according to claim 1, wherein the flash steam discharged from the steam discharge port is recovered. The flash vessel is connected to the heat exchanger via the steam outlet.
The reaction facility according to claim 2, wherein the flash steam discharged from the steam discharge port is recovered by the heat exchanger and heat exchanged. A gas charging pipe for charging inert gas or compressed air is connected to the receiving vessel, and the internal pressure is adjusted by charging the inert gas or compressed air through the gas charging pipe. The reaction facility according to any one of claims 1 to 3 . It is a slurry extraction method that extracts the slurry generated in an autoclave that reacts under high temperature and high pressure conditions.
The slurry containing the solid content generated in the autoclave is placed in the receiving vessel in a state where the pressure is equal to the pressure inside the autoclave or is kept lower than the internal pressure of the autoclave in the range of 0.2 MPa or more and 1.0 MPa or less. Transfer and
Next, only the supernatant liquid of the slurry introduced into the receiving vessel was transferred to the flush vessel provided with the flush valve while being rapidly decompressed.
In the receiving vessel, after the internal pressure is gradually reduced, the slurry containing the solid content remaining in the receiving vessel is extracted.
In the flash vessel, a method for extracting a slurry from an autoclave in which the introduced supernatant liquid is extracted and the flush vapor generated in the flush vessel is recovered. The fifth aspect of claim 5 , wherein the slurry introduced into the receiving vessel is allowed to stand, the solid content contained in the slurry is naturally settled to separate the slurry, and only the supernatant liquid of the slurry is transferred to the flash vessel. How to extract slurry from autoclave.

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