JP2018149496A - Method of operating decompressed type surplus low-water distillation facility and sealing liquid temperature control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for operating a reduced pressure type surplus water distillation facility capable of more reliably preventing a suction failure due to naphthalene.
See the correspondence between the concentration of naphthalene contained in the ammonia-containing vapor sucked by a liquid ring vacuum pump and the temperature of the liquid seal of the liquid ring vacuum pump where naphthalene is deposited in the liquid ring vacuum pump. Then, a temperature higher than the temperature of the sealing liquid corresponding to the current concentration of naphthalene is set as the target temperature, and the temperature of the sealing liquid in the liquid ring vacuum pump is controlled so as to be the set target temperature.
[Selection] Figure 1

Description

  The present invention relates to a method for operating a reduced pressure excess surplus water distillation facility and a sealing liquid temperature control device.

Conventionally, as an operation method of the reduced pressure type surplus water distillation equipment, for example, there are techniques described in Patent Documents 1 and 2. In the techniques described in Patent Documents 1 and 2, before the surplus water is introduced into the decompression-type safe water distillation equipment, the naphthalene contained in the surplus water is removed by a filter, so that Is disclosed to prevent poor suction due to naphthalene.
However, since the techniques described in Patent Documents 1 and 2 require a filter, the equipment may be expensive, and it is uncertain whether an appropriate effect can be actually obtained.

JP-A-61-83290 JP-A-61-83291

  This invention pays attention to the above points, and it aims at provision of the operating method of the pressure reduction type surplus water distillation equipment and the sealing liquid temperature control apparatus which can prevent the suction failure by naphthalene more reliably.

  In order to solve the above-mentioned problem, one aspect of the present invention is as follows. (A) Ammonia containing distillate from a vacuum distillation column by introducing surplus water produced during the purification of coke oven gas into the vacuum distillation column (B) ammonia sucked by a predetermined liquid ring vacuum pump, including the step of introducing vapor into the condenser to cool and condense, and sucking ammonia-containing vapor from the condenser with a liquid ring vacuum pump Referring to the correspondence between the concentration of naphthalene contained in the vapor and the temperature of the liquid seal of the liquid ring vacuum pump where naphthalene is deposited in the liquid ring vacuum pump, the seal solution corresponding to the current concentration of naphthalene The temperature is higher than the target temperature, and (c) the operation method of the reduced pressure surplus water distillation equipment for controlling the temperature of the sealing liquid in the liquid ring vacuum pump so as to be the set target temperature. Is the gist .

  In another aspect of the present invention, (a) surplus water generated during the purification of coke oven gas is introduced into a vacuum distillation column and distilled under reduced pressure, and ammonia-containing vapor distilled from the vacuum distillation column is introduced into the condenser. The liquid seal temperature control device for controlling the temperature of the liquid seal in the liquid ring vacuum pump of the reduced pressure surplus water distillation facility that sucks ammonia-containing vapor from the condenser with the liquid ring vacuum pump (B) Correspondence between the concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump and the temperature of the liquid seal of the liquid ring vacuum pump at which naphthalene precipitates in the liquid ring vacuum pump With reference to the correspondence between the storage unit storing the relationship and (c) the concentration of naphthalene stored in the storage unit and the temperature of the sealing liquid, the temperature of the sealing liquid corresponding to the current concentration of naphthalene Set a higher temperature as the target temperature. And, and summarized in that a sealing liquid temperature controller and a sealing liquid temperature controller for controlling the temperature of the sealing liquid in the liquid seal vacuum pump so that the target temperature set.

  According to the present invention, since the precipitation of naphthalene in the liquid ring vacuum pump is suppressed, the operation method of the reduced pressure surplus water distillation equipment and the sealing liquid temperature control device that can prevent suction failure due to naphthalene more reliably. Can be provided.

It is a block diagram showing the structure of the pressure reduction type surplus water distillation equipment which concerns on embodiment. It is a figure showing the structure of a liquid ring vacuum pump, (a) is a side view, (b) is sectional drawing which shows the cross section fractured | ruptured by the AA cross section of (a). It is a graph showing the correspondence between the concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump and the temperature of the liquid seal of the liquid ring vacuum pump where naphthalene is deposited in the liquid ring vacuum pump. . It is a flowchart showing the sealing liquid temperature control process which CPU performs.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the shape, structure, arrangement, etc. of components. Is not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

  In the coke factory, since the coke oven gas is purified with ammonia water circulating between the dry main of the coke oven and the tar decanter, ammonia water (hereinafter referred to as 70 ° C. to 80 ° C.) containing harmful substances such as ammonia. Also called “hot water”. And the surplus safe water among the generated hot water is processed by vacuum distillation equipment, and ammonia is removed.

  In the operation method of the reduced pressure surplus water distillation facility of the present embodiment, surplus water generated during the purification of the coke oven gas is introduced into the reduced pressure distillation column of the reduced pressure surplus water distillation facility, and the surplus introduced by the reduced pressure distillation is introduced. Remove ammonia from the aqueduct. And the ammonia containing vapor | steam distilled from the vacuum distillation tower is condensed by introduce | transducing into the condenser of a pressure reduction type surplus water distillation equipment, and cooling. At that time, the condensed ammonia-containing vapor is sucked from the condenser with a liquid ring vacuum pump. At this time, since the sealing liquid of the liquid ring vacuum pump and the ammonia-containing vapor are in contact with each other, naphthalene contained in the ammonia-containing vapor is precipitated in the liquid ring vacuum pump, and the impeller of the liquid ring vacuum pump is fixed. There is a risk that poor suction, that is, vacuum abnormality in the vacuum distillation column may occur.

  However, in the operation method of the reduced pressure type surplus water distillation equipment of this embodiment, the concentration of naphthalene contained in the ammonia-containing vapor sucked by the sealed vacuum pump and the liquid seal in which naphthalene is precipitated in the liquid sealed vacuum pump. The relationship with the temperature of the sealing liquid of the vacuum pump was obtained, and the temperature higher than the temperature of the sealing liquid corresponding to the current concentration of naphthalene was set as the target temperature with reference to the corresponding relationship. The temperature of the sealing liquid in the sealing liquid vacuum pump is controlled so as to reach the target temperature. Here, as the target temperature, for example, considering the possibility that the temperature of the sealing liquid may fluctuate, a temperature that is 2 to 3 ° C. higher than the temperature of the sealing liquid corresponding to the current concentration of naphthalene is set. preferable. Therefore, precipitation of naphthalene contained in the ammonia-containing vapor in the liquid-sealed vacuum pump due to contact between the sealing liquid of the liquid-sealed vacuum pump and the ammonia-containing vapor is suppressed. Therefore, sticking of the impeller of the liquid ring vacuum pump due to the deposited naphthalene is suppressed, and the vacuum abnormality in the vacuum distillation tower is suppressed, so that the suction failure due to naphthalene is more reliably prevented.

In such an operation method of the reduced-pressure type surplus water distillation facility of the present embodiment, for example, before surplus water is introduced into the reduced-pressure-type safe water distillation facility, naphthalene contained in the surplus water is removed by a filter. Compared to the method of doing, the equipment is cheaper. Furthermore, since surplus water is processed by vacuum distillation, it is not necessary to make the surplus water in a vacuum distillation tower high temperature, and energy cost can be reduced.
Next, the operation method of the decompression type surplus water distillation equipment of this embodiment will be described with reference to more specific examples (see FIGS. 1 to 3).

As shown in FIG. 1, surplus water generated during refining of coke oven gas is removed through a path 2 through a vacuum distillation tower 1 of a vacuum distillation facility (hereinafter referred to as “energy-saving (decompression type) surplus water treatment distillation tower 1 Is also called). The pressure-reducing surplus water treatment distillation column 1 is decompressed by a liquid ring vacuum pump 16 (described later) sucking ammonia-containing vapor from a condenser 11 (described later).
The surplus water introduced into the reduced pressure type surplus water treatment distillation column 1 is sent to the reboiler 3 from the bottom of the tower via the circulation pump 5 and the path 6 and heated by heat exchange, and then the reduced pressure type surplus water treatment distillation. Returned to the tower bottom of tower 1. Thereby, the heated surplus water becomes steam under reduced pressure, and ammonia-containing steam containing ammonia and acidic gas at a high concentration reaches the top of the decompression-type surplus water treatment distillation column 1. As a result, surplus water is stripped, and ammonia and acid gas are removed. The surplus water from which ammonia and acid gas have been removed is extracted from the bottom of the reduced pressure surplus water treatment distillation column 1 by the deaeration water pump 8 and sent via the path 9.

The heat source of the reboiler 3 is not particularly limited, but hot water that circulates between the dry main of the coke oven and the tar decanter may be used. In other words, the circulating hot and cold water may be introduced into the reboiler 3 via the path 4 to serve as a heat source.
The ammonia-containing vapor removed from the surplus water is sucked by the liquid ring vacuum pump 16 from the top of the decompression-type surplus water treatment distillation column 1 and is supplied to the decompression-type surplus water treatment distillation column 1 via the path 10. It is introduced into the condenser 11. A large number of tubes (not shown) are arranged in the condenser 11 along the vertical direction, and ammonia-containing vapor is introduced into these tubes. And ammonia containing vapor | steam condenses by being cooled with the cooling water which flows the exterior of a tubular body.

  Ammonia water obtained by condensing the ammonia-containing vapor is extracted from the bottom of the condenser 11 by the pump 17 and fed through the path 18. This ammonia water can be used as circulating hot water, or it can be distilled to obtain highly pure ammonia. In addition, the ammonia-containing vapor that has not been condensed is discharged from the bottom of the condenser 11 through the path 15 by the liquid ring vacuum pump 16 and processed in the deammonia facility. Further, the condensed ammonia-containing vapor is sucked from the condenser 11 by a liquid ring vacuum pump 16.

  Here, as shown in FIG. 2, the liquid ring vacuum pump 16 is provided with a casing 16d having a cylindrical inner space 16a, an intake port 16b and an exhaust port 16c, and is eccentrically provided in the inner space 16a. An impeller 16f having 16e, a rotary electric motor 16g for rotating the impeller 16f, and a sealing liquid supply pipe 16i for supplying the sealing liquid 16h into the casing 16d are provided. Then, the sealing liquid 16h is supplied from the sealing liquid supply pipe 16i to the internal space 16a of the casing 16d, and the impeller 16f is rotated by the rotary electric motor 16g, thereby forming a liquid ring in the internal space 16a of the casing 16d by centrifugal force. . Further, the ammonia-containing vapor taken from the intake port 16b into the air chamber formed by the adjacent blades 16e and the liquid ring is compressed by reducing the volume of the air chamber accompanying the rotation of the impeller 16f, and by the rotation of the impeller 16f. When the air chamber reaches the exhaust port 16c, the ammonia-containing vapor compressed in the air chamber is exhausted from the exhaust port 16c.

Returning to FIG. 1, the vacuum distillation facility further includes a measuring unit 19, a heater 20, and a sealing liquid temperature control device 21. The sealing liquid temperature control device 21 includes a storage unit 21a, an information input unit 21b, and a sealing liquid temperature control unit 21c.
The measuring unit 19 is provided in the sealing liquid supply pipe 16 i and measures the temperature of the sealing liquid 16 h in the sealing liquid supply pipe 16 i, that is, the temperature of the sealing liquid 16 h supplied to the liquid sealing vacuum pump 16. For example, a thermocouple thermometer is used as the measurement unit 19. And the measurement part 19 outputs a measurement result to the sealing liquid temperature control part 21c.

The heater 20 for heating is provided in the sealing liquid supply pipe 16i, and the sealing liquid 16h in the sealing liquid supply pipe 16i, that is, the sealing supplied to the liquid sealing vacuum pump 16 in accordance with a command from the sealing liquid temperature control unit 21c. The liquid 16h is heated. As the heater 20 for heating, for example, an in-line heater or a flange heater is used.
As shown in FIG. 3, the storage unit 21 a includes a predetermined concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump 16 and a seal in which naphthalene is deposited in the liquid ring vacuum pump 16. The correspondence with the temperature of the liquid 16h is stored. The correspondence between the concentration of naphthalene and the temperature of the sealing liquid 16h is examined by using an actual reduced-pressure night water distilling facility for night use in advance experiments or the like. For example, a hard disk is used as the storage unit 21a.

  The information input unit 21b receives an input of the concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump 16 from the operator. And an input result is output to the sealing liquid temperature control part 21c. For example, a keyboard or a touch panel is used as the information input unit 21b. The concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump 16 is obtained by manually collecting and analyzing the ammonia-containing vapor in the passage 15. It is also possible to perform continuous measurement with a densitometer instead of manual analysis.

  The sealing liquid temperature control unit 21c includes an A / D (Analog to Digital) conversion circuit, a D / A (Digital to Analog) conversion circuit, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). ) Etc. are provided. The ROM stores programs for realizing various processes. When the information input unit 21b outputs the input result, the CPU executes a sealing liquid temperature control process for controlling the temperature of the sealing liquid 16h according to a program stored in the ROM.

When the sealing liquid temperature control process is executed, as shown in FIG. 4, first, in step S <b> 1, the CPU acquires the input result (the current naphthalene concentration) output by the information input unit 21 b.
Subsequently, the process proceeds to step S2, and the CPU refers to the stored contents of the storage unit 21a, and the liquid-sealed vacuum pump corresponding to the concentration of naphthalene represented by the input result obtained in step S1, that is, the current concentration of naphthalene. A temperature higher than the temperature of 16 sealing liquids 16h is set as a target temperature. As a method for setting the target temperature, for example, a method of setting a temperature that is a predetermined temperature higher than the temperature of the sealing liquid 16h corresponding to the current concentration of naphthalene as the target temperature can be adopted. For example, considering the possibility that the temperature of the sealing liquid 16h fluctuates, it is preferable to set a temperature that is 2 to 3 ° C. higher than the temperature of the sealing liquid 16h corresponding to the current naphthalene concentration.

Then, it transfers to step S3 and CPU acquires the measurement result of the temperature of the sealing liquid 16h which the measurement part 19 output.
Subsequently, the process proceeds to step S4, and the CPU instructs to heat the sealing liquid 16h in the sealing liquid supply pipe 16i so that the temperature of the sealing liquid 16h acquired in step S3 becomes the target temperature set in step S2. Is output to the heater 20 and then the process returns to step S3. Thereby, it heats with the heater 20 for heating, and controls the temperature of the sealing liquid 16h.

  In such a sealing liquid temperature control device 21 of the present embodiment, the operator measures the concentration of naphthalene contained in the ammonia-containing vapor and inputs the measurement result, and the sealing liquid 16h corresponding to the current concentration of naphthalene is obtained. Control of the temperature of the sealing liquid 16h is performed so that the temperature (target temperature) is higher than the above temperature. Therefore, it is possible to reduce time and effort required for controlling the temperature of the sealing liquid 16h.

Moreover, in the sealing liquid temperature control apparatus 21 of this embodiment, since the apparatus structure for performing temperature control can be simplified, the pressure reduction type surplus water distillation equipment can be made inexpensive.
In the present embodiment, an example in which the target temperature is set by the sealing liquid temperature control unit 21c has been described, but other configurations may be employed. For example, a graph showing the correspondence between the concentration of naphthalene contained in the ammonia-containing vapor and the temperature of the sealing liquid 16h at which naphthalene precipitates in the liquid-sealed vacuum pump 16 is prepared, and the operator refers to the graph. The target speed may be set manually based on the concentration of naphthalene contained in the current ammonia-containing vapor.

DESCRIPTION OF SYMBOLS 1 ... Depressurization type surplus water treatment distilling column, 2 ... Path | route, 3 ... Reboiler, 4 ... Path | route, 5 ... Circulation pump, 6 ... Path | route, 8 ... Dewatered water pump, 9, 10 ... Path | route, 11 ... Condenser DESCRIPTION OF SYMBOLS 15 ... Path | route, 16 ... Liquid-sealed vacuum pump, 16a ... Internal space, 16b ... Intake port, 16c ... Exhaust port, 16d ... Casing, 16e ... Wing, 16f ... Impeller, 16g ... Rotary motor, 16h ... Sealed liquid, 16i ... Sealing liquid supply pipe, 17 ... Pump, 18 ... Path, 19 ... Measuring part, 20 ... Heating heater, 21 ... Sealing liquid temperature control device, 21a ... Storage part, 21b ... Information input part, 21c ... Sealing liquid temperature Control unit

Claims (3)

The surplus water generated during the purification of the coke oven gas is introduced into a vacuum distillation column and distilled under reduced pressure, and the ammonia-containing vapor distilled from the vacuum distillation column is introduced into a condenser to be cooled and condensed, and the condenser Including sucking ammonia-containing vapor with a liquid ring vacuum pump from
The predetermined concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump and the temperature of the liquid seal of the liquid ring vacuum pump at which the naphthalene is deposited in the liquid ring vacuum pump. Referring to the correspondence relationship, a temperature higher than the temperature of the sealing liquid corresponding to the current concentration of naphthalene is set as the target temperature, and the sealing liquid in the liquid sealing vacuum pump is set to the set target temperature. A method for operating a reduced pressure surplus water distillation facility characterized by controlling temperature. The surplus water generated during the purification of the coke oven gas is introduced into a vacuum distillation column and distilled under reduced pressure, and the ammonia-containing vapor distilled from the vacuum distillation column is introduced into a condenser to be cooled and condensed, and the condenser A liquid-sealed vacuum control device for controlling the temperature of the liquid-sealed vacuum pump in the liquid-sealed vacuum pump of the reduced pressure surplus water distillation facility for sucking ammonia-containing vapor from the liquid-sealed vacuum pump,
Stores the correspondence between the concentration of naphthalene contained in the ammonia-containing vapor sucked by the liquid ring vacuum pump and the temperature of the liquid seal of the liquid ring vacuum pump at which the naphthalene is deposited in the liquid ring vacuum pump. Storage unit
With reference to the correspondence stored in the storage unit, a temperature higher than the temperature of the sealing liquid corresponding to the current concentration of naphthalene is set as a target temperature, and the sealing liquid in the liquid sealing vacuum pump is set. A sealing liquid temperature control apparatus comprising: a sealing liquid temperature control unit configured to control the temperature of the sealing liquid in the liquid sealing vacuum pump so that the temperature becomes a set target temperature. A measuring unit for measuring the temperature of the sealing liquid in the sealing liquid supply pipe of the liquid ring vacuum pump;
A heater for heating the sealing liquid in the sealing liquid supply pipe,
The sealing liquid temperature control unit causes the heating heater to heat the sealing liquid in the sealing liquid supply pipe so that the temperature of the sealing liquid measured by the measurement unit becomes the target temperature. Item 3. The sealing liquid temperature control device according to Item 2.

Images