JPH0570490B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention particularly relates to a gas separation apparatus having a plurality of gas separation cascades arranged, which can make full use of the equipment capacity and can obtain a large amount of product streams with various concentrations. <Prior art> Conventionally, in order to obtain a product stream containing a predetermined concentration of a specific component gas from a mixed gas system, such as when producing enriched uranium products in a uranium enrichment plant, separation elements such as centrifuges have been used. A gas separation cascade in which a plurality of gases are arranged is used to increase the effect of separating a specific component gas from a mixed gas system and increase the throughput. Furthermore, in order to obtain a large quantity of a product stream containing a predetermined concentration of this particular gas component, N identical cascades 11, 12, . . . 1N, as shown in FIG.
is connected to the raw material supply pipe 20 and its branch pipes 21, 22...2N
A branch pipe 3 that joins the waste gas pipe 30 via
cascade 11,1 via 1,32...3N
A gas separation device is used in which product flow pipes 41, 42, ...4N of 2,...1N are directly connected to one collection pipe 51. Furthermore, the enrichment rounds are required to have a wide range of enrichment, with the highest and lowest enrichment ratios being as high as three times, depending on the light water reactor used. Furthermore, it is a technology that can obtain product streams with different concentrations while maintaining optimal conditions in the same cascade without reorganizing the cascade, arranging multiple types of cascades, or operating outside of the designed optimal conditions. It is composed of a number of separation elements having an asymmetric separation process, that is, a process in which the head separation coefficient and the tail separation coefficient, which are the separation coefficients of the concentrated stream and the depleted stream produced by separation of the raw materials supplied in the separation element, are different. using a gas separation cascade from which multiple product streams of different concentrations are removed;
A method has been proposed in which a plurality of arbitrary product streams are combined, mixed, and collected to thereby adjust the concentration (Japanese Patent Application Laid-open No. 65722/1983). <Problem to be solved by the invention> For example, by using the gas separation device shown in FIG.
When it is desired to obtain productively product streams of various enrichments in the range W _i to W _j (3W _i W _j ), the equipment settings are usually set to the average enrichment (W _i +
W _j )/2. The operation is then performed by adjusting the flow rate, pressure, etc. In this case, the average concentration (W _i + W _j )/2 is set as shown in Figure 4.
When producing a product with a concentration that deviates from the standard, there is a problem that the operating efficiency decreases and the service capacity of the equipment cannot be fully utilized. In addition, as a countermeasure to this problem, we changed the operating state by adjusting the processing flow rate of each centrifuge of cascades 1 to N.
Responding to changes in product concentration may affect the rotational performance and safety of the centrifuge depending on the conditions, and may also cause problems such as not being able to accommodate all product concentrations. In order to
Usually, there are problems such as requiring the addition of new equipment for concentration adjustment and new operations associated with this equipment. In addition, the gas separation device shown in Fig. 3 can be used to generate a plurality of different enrichments without adjusting the processing flow rate of the centrifuge, for example, by disconnecting and reconnecting the top stage of the cascade enrichment zone during operation. Although it is possible to obtain a product stream, in this case, there are problems in that the top stage centrifugal separator becomes idle when the centrifugal separator is disconnected, and the equipment is interrupted when the number of stages is changed, reducing the operating rate. As described above, the conventional gas separation apparatus in which a plurality of gas separation cascades are arranged as shown in FIG. 3 cannot manufacture product streams having various different concentrations by utilizing the full capacity of the equipment. On the other hand, a single gas separation cascade does not provide a large product stream. Therefore, it is an object of the present invention to provide a gas separation device in which a plurality of gas separation cascades are arranged, which can make full use of the equipment's capacity and obtain a large amount of product streams with various different concentrations. . <Means for Solving the Problems> In other words, the gas separation device of the present invention has a plurality of gas separation cascades, and a product flow pipe for discharging product gas from each gas separation cascade is connected to a collection pipe. In the separation device, a plurality of the collection pipes are provided, and flow rate adjustment is performed for each of the product flow pipes from each gas separation cascade that outputs a plurality of types of product gases having different concentrations, and for each of the plurality of collection pipes. The device is characterized in that it is connected via means. The gas separation cascade constituting this device can be a gas separation cascade with one product flow pipe that discharges a product stream with one type of concentration, or a gas separation cascade with multiple product flow pipes that each discharge a product stream with a different concentration. A gas separation cascade with product flow piping can be used. Regardless of which gas separation cascade is used, it is sufficient to connect each product flow pipe to each of the plurality of collection pipes via a flow rate adjusting means. <Function> When raw material gas is supplied to each gas separation cascade of the gas separation device of the present invention, specific components of this raw material gas are concentrated by separation elements such as centrifuges already invented in each gas separation gascade. The gas is separated into a gas diluted in specific components. After the former gas flows out from the gas separation cascade through each product flow pipe, it flows into each collection pipe in a predetermined amount while controlling the mixed flow rate by a flow rate regulating means. By distributing the product streams having different concentrations by the flow rate adjusting means and merging and mixing them in each collection pipe, a predetermined amount of products having different concentrations can be obtained from each collection pipe. <Examples> The present invention will be specifically described below by showing examples with reference to the drawings. FIG. 1 shows an example of this gas separation device, and this device has enrichment degrees W _A , W _B , ...,
Gas separation cascades 1A, 1B, capable of discharging product gas W _Z at flow rates V _A , V _B , ..., V _Z ,
..., 1Z. These gas separation cascades 1A, 1B, ..., 1Z, when supplied with raw materials, separate the concentrated stream from a separation element (not shown) having an equal separation coefficient, that is, a head separation coefficient and a tail separation number,
For example, it has a configuration in which a plurality of centrifugal separators are arranged. In addition, gas separation cascades 1A, 1B,..., 1
Z is connected to the raw material supply pipe 20 for supplying raw material gas via its branch pipes 2A, 2B..., 2Z, and when the raw material gas is supplied to the raw material supply pipe 20, it passes through the branch pipes 2A, 2B..., 2Z. Thus, raw material gas is supplied to each gas separation gascade 1A, 1B, . . . , 1Z. Similarly, a waste gas pipe 30 is connected to the gas separation cascades 1A, 1B...1Z via branch pipes 3A, 3B...3Z that merge therewith, and the waste gas discharged from the gas separation cascades 1A, 1B..., 1Z is Branch pipes 3A and 3B respectively
..., 3Z, joins the waste gas pipe 30, and is discharged from the waste gas pipe 30. Furthermore, gas separation cascades 1A, 1B..., 1Z
are the product flow piping 4 that discharges each product gas.
A ₁ , 4B ₁ ,...4Z ₁ are each three collection pipes 5
1, 52, 53 all have branch pipes 4A ₂ , 4B ₂ ,...,
Connected via 4Z ₂ and 4A ₃ , 4B ₃ , ...4Z ₃ ,
Further, a flow rate control valve is provided between each, for example, a flow rate control valve _6A1 is provided between the product flow pipe _4A1 and the collection pipe 51, and a flow rate control valve is provided between the branch pipe _4A2 and the collection pipe 52. 6A ₂ is the branch pipe 4A ₃ and collection pipe 53
A flow control valve _6A3 is provided between the two. Similarly, product flow pipes 4B ₁ , 4B ₂ , 4B ₃ and collection pipe 5
1, 52, and 53, each has a flow rate control valve 6.
B ₁ , 6B ₂ , 6B ₃ are provided, and product flow piping 4Z ₁ ,
Flow control valves 6Z ₁ , 6Z 2 and 6Z ₃ are provided between 4Z ₂ and 4Z ₃ and collection pipes 51, 52 and ₅₃ , respectively. According to the gas separation device having the above configuration, the raw material gas is supplied to the gas separation cascades 1A, 1B..., 1Z.
When the capacity of the gas separation cascades A, B, ..., Z is fully utilized, the concentration of each gas flowing out from the gas separation cascades A, B, ..., Z
_{The product} flow of W _{A ,} W _B ,...W _Z and _the flow _rate V _A , V _B ,..., V
By B ₁ , 6B ₃ , ...6Z ₁ , 6Z ₂ , 6Z ₃ , first,
Flow rates V _A1 , V _A2 , with the same concentration satisfying the following formula (1),
The current is divided into V _A3 , V _B1 , V _B2 , V _B3 , ...V _Z1 , V _Z2 , and V _Z3 .

[Table] ^{i=1 i=1 i=1} 〓
Next, flow rates V ₁ , V ₂ , and V 3 given by the following equations (2) are generated in each of the collection pipes 51 , 52 , and ₅₃ by merging, and the concentration W ₁ ,
W ₂ and W ₃ are as shown in the following equation (3).

[Table] ^j=A 〓 (3)
W ₂ =

Claims (1)

[Scope of Claims] 1. A gas separation device having a plurality of gas separation cascades, in which a product flow pipe for discharging product gas from each gas separation cascade is connected to a collection pipe, in which a plurality of said collection pipes are connected. and each of the product flow pipes from each gas separation cascade that outputs a plurality of types of product gases with different concentrations is connected to each of the plurality of collection pipes via a flow rate adjusting means. gas separation equipment. 2. Each of the plurality of gas separation cascades is a gas separation cascade comprising one product flow pipe through which a product gas of one type of concentration flows out,
Claim 1, wherein each of the product flow pipes and each of the plurality of collection pipes are connected via a flow rate adjusting means.
The device described. 3. Each of the plurality of gas separation cascades is a gas separation cascade comprising a plurality of product flow pipes that discharge product gases having different concentrations, each of the plurality of gas separation cascades having a plurality of product flow pipes and a plurality of collection pipes. 2. The device according to claim 1, wherein each of the devices is connected via a flow rate adjusting means.