JP2014008462A - Dehumidifier, dehumidification system structured by the same, and dehumidification processing method of processed gas by the same dehumidifier and dehumidification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dehumidifier which can discharge by securely reducing a water content in processed gas to a set value or lower.SOLUTION: A dehumidifier mainly includes dehumidifying towers 1A, 1B. Each of the dehumidifying towers 1A, 1B includes a conducting path 3 in a center part of a filled layer 2 of a dehumidifying agent, and a heating cylinder 4 inserted in the conducting path 3, and further includes a processed gas introducing path 5 connected to an upper end part of the filled layer 2. The processed gas introducing path is provided with a differential pressure type flowmeter 20A as a flow rate detection means of the processed gas; a dew-point meter 20B as a water content detection means of the processed gas; an operational circuit OC of operating an accumulated water amount absorbed in the filled layer 2 from the differential pressure type flowmeter 20A and the dew-point meter 20B; and a switching means which switches introduction of the processed gas to the dehumidifying towers 1A, 1B to introduction of regeneration gas by a signal output from the operational circuit OC.

Description

  The present invention relates to a dehumidifying device used for removing moisture from a gas to be treated such as an atmospheric gas in an industrial furnace, a dehumidifying system constituted by the dehumidifying device, and a method for dehumidifying the gas to be treated by them. It is about.

Conventionally, as this type of dehumidifying apparatus, for example, as in Patent Document 1, the gas to be treated is introduced into a dehumidifying tower having a packed layer of a dehumidifying agent therein, and the gas to be treated is supplied to the dehumidifying tower packed bed. The thing of the structure which dehumidifies by passing in is proposed.
In the dehumidifying apparatus, when the amount of moisture adsorbed on the dehumidifying agent filling layer reaches saturation, the dehumidifying process is stopped and the dehumidifying agent filling layer is heated to remove the moisture adsorbed on the dehumidifying agent filling layer. A regeneration process is performed.
Therefore, it is necessary to switch the dehumidification step and the regeneration step at an appropriate time. In the above conventional example, a flow meter and a dew point meter are set on the outlet side of the dehumidification tower, the moisture of the treated gas exhausted from the dehumidifying tower is measured, and the moisture content of the treated gas is There is provided a method of switching from the dehumidification process to the regeneration process when the set value is exceeded.

JP 59-136119 A

However, in the above-described conventional method, there is a possibility that the treated gas having a moisture content equal to or higher than the set value is discharged from the dehumidifying tower before switching to the regeneration process.
It is an object of the present invention to provide a dehumidifying device that does not discharge a processed gas containing water that exceeds a set value.

As means for solving the above-mentioned problems, the present invention provides a dehumidifying device used to remove moisture contained in a gas to be treated, the dehumidifying device comprising a packed layer of a dehumidifying agent and a heating means. In the dehumidification tower, in the dehumidification tower, a conduction path communicating with the upper and lower sides of the dehumidification tower is provided at the center of the packed bed, and the upper end of the dehumidification tower is provided in the conduction path. Further, a heater is inserted, and the dehumidifying tower further includes a treated gas introduction path communicating with the upper end of the packed bed, a treated treated gas discharge path communicating with the upper end of the dehumidifying tower, and the above A regeneration gas introduction path communicating with the upper end of the dehumidification tower, a used regeneration gas discharge path communicating with the upper end of the packed bed, a cooling gas introduction path communicating with the upper end of the packed bed, and the dehumidification tower A spent cooling gas discharge passage communicating with the upper end, The process gas introduction path is provided with a flow rate detection means for the process gas, a moisture content detection means for the process gas, a flow rate detection means for the process gas, and a moisture content of the process gas. A calculation circuit for calculating an integrated moisture amount adsorbed on the packed bed from the amount detection means, and a switching means for switching the introduction of the gas to be treated into the dehumidification tower to the introduction of the regeneration gas by a signal output from the calculation circuit And providing a dehumidifying device.
In the dehumidifying device, the cooling gas introduction path is united with an intermediate portion of the regeneration gas discharge path, and the treated gas introduction path, the regeneration gas discharge path, and the cooling gas introduction path are united. Connected to the dehumidification tower, the regeneration gas introduction path and the used cooling gas discharge path are combined and connected to the dehumidification tower, and the cooling gas introduction path and the used cooling gas discharge path are It is desirable to form a cooling gas circulation path by connecting via a gas cooling means.
Furthermore, in the present invention, the dehumidifying device is configured, and two dehumidifying towers are arranged side by side. In one dehumidifying tower, a dehumidifying process is performed in which dehumidification is performed by introducing a gas to be treated. In the tower, a regeneration gas is introduced to perform heating regeneration of the packed bed, and then a regeneration cooling process is performed in which a cooling gas is introduced and cooled, and a dehumidification step is performed between the two dehumidification towers every predetermined time. A dehumidification system is provided in which switching means for switching between regenerative cooling processes is interposed.
Furthermore, in the present invention, the dehumidifying device is used, and in the dehumidifying process of the gas to be processed, the gas to be processed is introduced from the gas to be processed introduction path to the upper part of the packed bed in the dehumidifying tower, The treated gas introduced into the upper part of the packed bed flows down through the packed bed and reaches the bottom of the dehumidifying tower and rises in the conduction path from the bottom of the dehumidified tower and connects to the upper end of the dehumidifying tower Although it is discharged from the discharge passage, the integrated amount of the gas to be treated introduced into the packed bed is detected by the flow rate detecting means interposed in the gas to be treated introduction passage, and further the water treatment detecting means by the moisture content detecting means. The moisture content of the gas is detected, the moisture adsorption amount of the packed bed is calculated from the integrated amount of the treatment gas introduced and the moisture content of the treatment gas by an arithmetic circuit, and the moisture adsorption amount reaches the saturation amount. If the gas to be treated is Switching from the wet treatment process to the regenerative cooling process of the packed bed, and in the regenerative cooling process of the packed bed, regenerative gas is introduced from the regenerative gas introduction path to the upper end of the dehumidifying tower as regeneration of the packed bed. The regeneration gas descends the conduction path of the packed bed and is heated to a predetermined temperature by the heater while reaching the bottom of the dehumidifying tower and then rises in the packed bed and is used from the top of the packed bed. As a regeneration gas, it is discharged to the regeneration gas discharge passage, and after the regeneration of the packed bed, as a cooling of the packed bed, a cooling gas is introduced into the upper portion of the packed bed from the cooling gas introduction passage, and the cooling gas descends in the packed bed However, the packed bed is cooled to reach the bottom of the dehumidifying tower, and then rises in the conduction path from the bottom of the dehumidifying tower and is discharged from the top of the dehumidifying tower to the cooling gas discharge path as used cooling gas. Dehumidification processing method of the scan is provided.
Furthermore, in the present invention, the above dehumidification system is used, the dehumidification tower performs a dehumidification process of the gas to be treated, the other dehumidification tower performs a regenerative cooling process, and the dehumidification tower performs the dehumidification process. When the process is completed and the regeneration cooling process in another dehumidification tower is completed, the dehumidification tower switches from the dehumidification process to the regeneration cooling process, and the other dehumidification tower switches from the regeneration cooling process to the dehumidification process. A method of dehumidifying gas is provided.
In the dehumidification processing method using the dehumidification system, when the accumulated moisture adsorption amount of the packed bed in one dehumidification tower reaches a predetermined set value set in a range of 75 to 85% of the saturation amount, It is desirable to adjust so that the dehumidification process in one dehumidification process is completed at the time when the regeneration cooling process in the other dehumidification tower is completed by reducing the speed of introducing the gas to be treated into the dehumidification tower.

[Action]
In the present invention, the flow rate detection means of the gas to be processed and the moisture content detection means of the gas to be processed are provided in the gas supply path to be processed, and the dehumidification tower passes through the gas supply path to be processed. By detecting the amount of gas to be treated and the moisture content of the gas to be treated, and calculating the integrated amount by a calculation circuit, the gas is adsorbed to the dehumidifying agent packed bed of the dehumidifying tower from the start of the treatment to that point. Accumulated water content can be confirmed. Since the moisture saturation adsorption amount of the dehumidifying agent-packed layer is obtained by multiplying the moisture saturation adsorption amount of the dehumidifying agent and the dehumidifying agent weight of the packing layer, when the accumulated moisture amount reaches the moisture saturation adsorption amount Thus, the dehumidification process may be switched to the regeneration process. In general, since the dehumidifying agent packed bed is regenerated by heating in the regeneration process, a subsequent cooling process is necessary. For the cooling, the regeneration gas is circulated through a circulation path, and the regeneration gas heated by the cooling means and the cooling in the middle are cooled. Use the cooled cooling gas.
In the dehumidification system in which two dehumidification towers are arranged side by side, the dehumidification process and the regeneration and cooling process are alternately performed for the two dehumidification towers. In a system in which two dehumidification towers are arranged side by side and the dehumidification process and the regeneration and cooling process are alternately performed, the dehumidification process time and the regeneration and cooling process time are the same so that each dehumidification tower is continuous. Thus, it is desirable to set so that the dehumidifying step and the regeneration step are performed. Therefore, when the production moisture adsorption amount of the packed bed in one dehumidification tower reaches a predetermined set value set in the range of 75 to 85% of the saturation amount, the introduction speed of the gas to be treated into the dehumidification tower is adjusted. (Decrease) so that the dehumidifying step of the one dehumidifying tower is completed when the regeneration cooling process of the other dehumidifying tower is completed.

〔effect〕
In the present invention, the moisture content of the gas to be treated can be reliably discharged below the set value.

The system diagram which shows the dehumidification system of an Example.

Examples for specifically describing the present invention will be described below.
As shown in FIG. 1, this embodiment relates to a dehumidification system including two dehumidification towers 1A and 1B. Inside the dehumidifying towers 1A and 1B, a packed bed 2 of a dehumidifying agent such as synthetic zeolite (trade name: molecular sieve) and activated alumina is installed, and a conduction path 3 is provided at the center of the packed bed 2. Is provided.
A heating cylinder 4 in which a heater H is inserted is inserted into the conduction path 3 from the upper ends of the dehumidifying towers 1A and 1B. The heater H is incorporated with a thermocouple for preventing air blown, and when the heater H reaches a set temperature or higher, the thermocouple is turned off. Further, the heater H is provided with a temperature display controller TIS.
The dehumidification towers 1A and 1B are connected to the path 5 for introducing the gas to be treated. A four-way valve 51 for switching the introduction of the gas to be treated between the dehumidifying tower 1A side and the dehumidifying tower 1B side is interposed in the path 5. The branch paths 5A and 5B branched from the four-way valve 51 are connected to the upper ends of the packed beds 2 and 2 in the dehumidification towers 1A and 1B.

Further, from the position above the packed layers 2 and 2 of the dehumidification towers 1A and 1B (upper end portions of the dehumidification towers 1A and 1B), a path for discharging the gas to be treated (treated gas) that has been dehumidified. 5 ′ and 5 ′ are respectively sent out. A four-way valve 6 for switching the discharge of the treated gas between the dehumidifying tower 1A side and the dehumidifying tower 1B side is interposed in the vicinity of the discharge ends of the above-described paths 5 ′ and 5 ′.
The regeneration gas (for example, nitrogen gas N ₂ ) is introduced from the regeneration gas source 8A into the dehumidifying towers 1A and 1B at the upper ends via the path 7 and the paths 5 ′ and 5 ′. And dehumidification tower 1B side.
The regeneration gas remaining in the system is diverted to the cooling gas source, the passage of the regeneration gas source 8A is blocked by the three-way valve 8B, and is directed to the path 9 through which the cooling gas is circulated.

  As the path for discharging the used regeneration gas, the paths 5A and 5B for introducing the gas to be treated are used, but the path 13 for discharging the used regeneration gas is further branched from the four-way valve 51. A regeneration gas release valve 14 is provided at the discharge end.

  A blower 15 is interposed in the path 9 through which the cooling gas is circulated, and a drain separator 16 and a regenerative cooler 17 are interposed downstream of the blower 15. The path 9 joins the path 13 on the four-way valve 51 side of the regeneration gas release valve 14. That is, the above-mentioned path also functions as a path for circulating the cooling gas on the side of the four-way valve 51 from the junction with the path 9, and the cooling gas is further distributed from the four-way valve 51 to the branch paths 5A and 5B. It introduce | transduces in dehumidification tower 1A, 1B.

  As described above, the path 5 is a path for mainly introducing the gas to be treated into the dehumidifying tower 1A or 1B. For this purpose, the gas to be treated is introduced at a predetermined flow rate. A booster blower 18 whose rotation speed is controlled by an inverter is interposed in the suction blower 18. A suction silencer 19 is attached to the suction port of the gas to be processed of the booster blower 18.

Further, a differential pressure type flow meter 20A provided with a differential pressure transmitter dPGI that measures the flow rate by measuring the differential pressure between the upstream side and the downstream side of the orifice 21 in the path 5 before the dehumidifying towers 1A and 1B. And a dew point meter D having a valve 23 for sucking the sample and a suction pump 24, and measuring a dew point of the sucked gas sample to be processed and a dew point meter 20B having a temperature sensor DP1 for measuring the sample temperature. ing.
Then, the flow rate data F of the gas to be processed measured by the flow meter 20A and the water content data M of the gas to be processed measured by the dew point meter 20B are calculated by the arithmetic circuit OC, and up to that point. The integrated moisture amount SW introduced into the dehumidifying tower 1A or the dehumidifying tower 1B is calculated.

In the above dehumidification system, a case will be described in which a dehumidifying step of the gas to be treated is performed in the dehumidifying tower 1A and the regenerative cooling of the packed bed 2 is performed in the dehumidifying tower 1B.
The gas to be treated is, for example, an atmospheric gas in an industrial furnace, mainly hydrogen gas and / or nitrogen gas.
Since the dehumidifying agent for the packed bed 2 of the dehumidifying towers 1A and 1B has a predetermined water absorption SWkg / kg per unit mass, the water absorbing capacity of the packed bed 2 is the total amount of dehumidifying agent WAkg packed in the packed bed 2. / Kg can be calculated.

[Dehumidification step by dehumidification tower 1A]
The gas to be treated is introduced into the dehumidifying tower 1A from the path 5 at a predetermined flow rate by the blower 18 as shown by an arrow A, but before that, the flow rate F is measured by the flow meter 20 and the moisture content is measured by the dew point meter 21. Measured and the integrated water amount SW is obtained by the arithmetic circuit OC.
The gas to be treated is introduced into the upper end of the packed bed 2 of the dehumidifying tower 1A, flows down in the packed bed 2 to remove moisture, reaches the bottom of the dehumidifying tower 1A, and is connected to the conduction path 3 as indicated by an arrow A. Ascending from the upper end of the dehumidifying tower 1A to the path 5 ′.

[Regeneration cooling by dehumidification tower 1B]
As a gas for regenerating the packed bed 2, nitrogen gas N ₂ is usually used.
In the regeneration step of regenerating the packed bed 2, the nitrogen gas N ₂ is introduced from the N ₂ source 8A into the path 7 through the three-way valve 8B, and dehumidified as indicated by the arrow B through the four-way valve 6. It is introduced into the tower from the upper end of the tower 1B, flows down the conduction path 3, and is heated by the heater H of the heating cylinder 4 during that time. The heating temperature of the heater H is adjusted by a temperature display controller TIS.
The heated regeneration gas reaches the bottom of the dehumidifying tower 1B, and further moves up in the packed bed 2 to heat and remove moisture adsorbed in the packed bed 2. The treated gas is as shown by an arrow B. Furthermore, the upper end of the packed bed 2 of the dehumidifying tower 1B reaches the path 13 through the branch path 5B and the four-way valve 51, and the discharge valve 14 is opened to be discharged to the outside.
In the regeneration step, since the packed bed 2 is heated not only by the regeneration gas but also by the radiant heat from the heating cylinder 4, high thermal efficiency is obtained.

When the regeneration of the packed bed 2 is completed, the cooling process is started. At the end of regeneration, the time necessary for heating and regenerating the dehumidified moisture is measured and set in advance.
In the cooling process, the regeneration gas N ₂ used in the regeneration process is used as the cooling gas, and as indicated by the arrow C, the three-way valve 8B is switched, and the path from the N ₂ source 8A is changed to the path 7 side. Leads to the circulation path 9. In the circulation path 9, the cooling gas is circulated by the blower 15. During this time, moisture condensed in the gas is removed by the drain separator 16, cooled by the regenerative cooler 17, and introduced into the path 13. As shown by the arrow C through the valve 51, the water is distributed to the branch path 5B and introduced into the upper end of the packed bed 2 of the dehumidifying tower 1B. That is, the path 13 and the branch path 5B are part of the cooling gas circulation path.
The cooling gas introduced into the packed bed 2 flows down in the packed bed 2 to cool the packed bed 2, and then goes up the conduction path 3 from the bottom of the packed bed 2 and from the upper end of the dehumidifying tower 1 </ b> B. It is discharged to the path 5 ′. The used cooling gas reaches the four-way valve 6 from the path 5 ′ as indicated by an arrow C, and is distributed to the path 7 by the four-way valve 6.

[Switching]
In the said Example, the dehumidification process of to-be-processed gas is implemented in the dehumidification tower 1A, and the reproduction | regeneration process and cooling process of the packed bed 2 are implemented in the dehumidification tower 1B. Then, when the dehumidification process in the dehumidification tower 1A is completed and the regeneration cooling process in the dehumidification tower 1B is completed, the regenerative cooling process is performed in the dehumidification tower 1A, and the dehumidification process is performed in the dehumidification tower 1B. 51 and the four-way valve 6 are switched. This switching signal measures the flow rate and water content of the gas to be processed, is calculated by the arithmetic circuit OC, is introduced into the dehumidifying tower 1A, and is adsorbed by the packed bed 2 to form the packed bed 2 described above. When the water absorption capacity WA (kg) × SW (kg / kg) (water absorption capacity limit) is reached, it is output by the arithmetic circuit OC.
In order to ensure that the dehumidification step and the regeneration cooling step are performed continuously, the dehumidification step of the dehumidification tower 1A and the regeneration cooling step of the dehumidification tower 1B are performed simultaneously or from the dehumidification step of the dehumidification tower 1A. It is desirable to operate so that the regenerative cooling process is completed early.
For example, in the case of dehumidification towers 1A and 1B having a packed bed 2 packed with 144 kg of molecular sieves, the amount of gas required for regeneration (N ₂ amount) is 30 Nm ³ / h, the amount of gas required for cooling is 40 Nm ³ / h, and the regeneration time is 5 hours, cooling time is set to 3 hours (circulation), a total of 8 hours of regeneration cooling process. Therefore, the flow rate of the gas to be processed is adjusted by the blower 18 so that the dehumidifying process is completed in 8 hours. Specifically, if the water absorption capacity of the packed bed 2 is 8 kg, the blower 18 is normally driven for 5 hours after the start of the dehumidification process, and the integrated water amount calculated by the arithmetic circuit OC is in the range of 75 to 85% of the water absorption capacity. When the amount reaches the amount set in (7), for example, 7 kg, the rotational speed of the blower 18 is decreased by the signal SM from the arithmetic circuit OC so that the remaining 1 kg can be adsorbed in 3 hours.

  In the present invention, since the moisture content of the gas to be treated can be surely set to a set value or less, it is industrially applicable.

1A, 1B Dehumidification tower 2 Packed bed 3 Conducting path 4 Heating cylinder 5 Path 5 'for introducing the gas to be treated Path 5' for discharging the treated gas 5A, 5B Branch path 51, 6, Four-way valve 9 Cooling gas Circulating path 13 Path for discharging used regeneration gas 14 Regeneration gas release valve 20 Flow meter 21 Dew point meter OC Calculation circuit

Claims (6)

A dehumidifying device used to remove moisture contained in a gas to be treated,
The dehumidifying apparatus mainly comprises a dehumidifying tower having a packed bed of a dehumidifying agent and a heating means inside,
In the dehumidification tower, a conduction path communicating with the top and bottom of the dehumidification tower is provided at the center of the packed bed, and a heater is inserted into the conduction path from the upper end of the dehumidification tower. Is a treated gas introduction path that communicates with the upper end of the packed bed, a treated treated gas discharge path that communicates with the upper end of the dehumidifying tower,
A regeneration gas introduction path that communicates with the upper end of the dehumidification tower, a spent regeneration gas discharge path that communicates with the upper end of the packed bed, a cooling gas introduction path that communicates with the upper end of the packed bed, and the dehumidification tower And a spent cooling gas discharge passage communicating with the upper end of the
The process gas introduction path includes a process gas flow rate detection unit, a process gas moisture content detection unit, a process gas flow rate detection unit, and a process gas moisture content detection unit. An arithmetic circuit for calculating the integrated water amount adsorbed on the packed bed, and a switching means for switching the introduction of the gas to be treated into the dehumidification tower to the introduction of the regeneration gas by a signal output from the arithmetic circuit. A dehumidifying device. The cooling gas introduction path is united with an intermediate portion of the regeneration gas discharge path,
The treated gas introduction path, the regeneration gas discharge path, and the cooling gas introduction path are combined and connected to the dehumidification tower, and the regeneration gas introduction path and the used cooling gas discharge path are combined. The dehumidifying device according to claim 1, wherein the dehumidifying tower is connected to the dehumidifying tower, and the cooling gas introduction path and the used cooling gas discharge path are connected via a gas cooling means to form a cooling gas circulation path. It is a dehumidification system comprised by the dehumidification apparatus of Claim 1 or 2.
Two dehumidification towers are juxtaposed,
In one dehumidification tower, a dehumidification process is performed in which the gas to be treated is introduced and dehumidified,
In other dehumidifying towers, regeneration gas is introduced to perform regeneration of the packed bed by heating, and then a regeneration cooling process is performed in which cooling gas is introduced for cooling.
A dehumidification system comprising a switching means for switching between the dehumidification process and the regeneration cooling process at predetermined intervals between the two dehumidification towers. Using the dehumidifying device according to claim 1 or 2,
In the dehumidifying process of the gas to be processed, the gas to be processed is introduced into the upper part of the packed bed in the dehumidifying tower from the gas inlet path, and the gas to be processed introduced into the upper part of the packed bed is introduced into the packed bed. It reaches the bottom of the dehumidification tower by flowing down and is discharged from the treated gas discharge path connected to the upper end of the dehumidification tower by rising from the bottom of the dehumidification tower through the conduction path.
The flow rate detecting means interposed in the gas to be processed introduction path detects the integrated amount of the gas to be processed introduced into the packed bed, and the water content detecting means detects the water content of the gas to be processed. When the moisture adsorption amount of the packed bed is calculated from the integrated amount of the gas to be treated and the moisture amount of the gas to be treated by an arithmetic circuit, and the moisture adsorption amount reaches the saturation amount, Switch from the dehumidification process of gas to the regeneration cooling process of the packed bed,
In the regenerative cooling process of the packed bed,
As regeneration of the packed bed, the regeneration gas is introduced from the regeneration gas introduction path to the upper end of the dehumidifying tower, and the regeneration gas descends the conduction path of the packed bed while being heated to a predetermined temperature by the heater. After reaching the bottom of the dehumidifying tower, the inside of the packed bed rises and is discharged from the upper part of the packed bed as a used regeneration gas into the regeneration gas discharge path
As the cooling of the packed bed after the regeneration of the packed bed, a cooling gas is introduced into the upper part of the packed bed from the cooling gas introduction path, and the dehumidifying is performed by cooling the packed bed while the cooling gas descends in the packed bed. A method for dehumidifying a gas to be treated, which reaches the bottom of the tower, rises from the bottom of the dehumidifying tower through the conduction path, and is discharged from the top of the dehumidifying tower as a used cooling gas to a cooling gas discharge path. Using the dehumidification system according to claim 3,
The dehumidification tower performs the dehumidification process of the gas to be treated, the other dehumidification tower performs the regenerative cooling process, the dehumidification process in the one dehumidification tower is completed, and the regenerative cooling process in the other dehumidification tower is completed. A dehumidifying treatment method for a gas to be treated, wherein the dehumidifying tower is switched from the dehumidifying process to the regenerative cooling process, and the other dehumidifying tower is switched from the regenerative cooling process to the dehumidifying process. When the accumulated water adsorption amount of the packed bed in one dehumidifying tower reaches a predetermined set value set in a range of 75 to 85% of the saturation amount, the rate of introducing the gas to be treated into the dehumidifying tower is reduced. The method for dehumidifying a gas to be treated according to claim 5, wherein the dehumidifying step in one dehumidifying step is adjusted to be completed when the regeneration cooling step in the other dehumidifying tower is completed.

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