JPH0587445A - Condensate evaporator and circuit therefor - Google Patents

Abstract

(57) [Abstract] [Purpose] In a condensation evaporator in which a condensing-side fluid containing a non-condensing gas is introduced into the condensing side, the non-condensing gas can be reliably treated, desired components can be recovered without waste, and stable operation is possible. Provided is a condensing evaporator. A gas-liquid separator 21 or a vent pipe 42 is provided on the condensation-side fluid outlet side of the condenser 20, and a lead-out pipe for leading out the multi-component condensation-side fluid from the gas layer separated by the gas-liquid separator 21. 23 is provided, and the outlet pipe 23 or the vent pipe 4 is provided.
2 is connected to the product sampling system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing evaporator and its system, and more particularly, to a condensing side fluid composed of a multi-component gas containing a non-condensing gas and a vapor composed of a single component or a multi-component liquid. The present invention relates to a system on the condensation side in a condensation evaporator that exchanges heat with a side fluid.

[0002]

2. Description of the Related Art For example, in a crude argon column of an air liquefaction separation apparatus, a crude argon condenser for condensing and liquefying crude argon consisting of multi-component gas using liquefied air as a refrigerant is used. The treatment of nitrogen gas, which is a non-condensable gas, has become an important issue.

FIG. 6 shows an example of a system of a conventional general air liquefaction separation device. As is well known, this air liquefaction separation device introduces raw material air that has been compressed, purified and cooled in the main heat exchanger 1 into the lower column 3 of the double rectification column 2 and liquefaction rectified to produce nitrogen gas and oxygen. Separated into liquefied air rich in components, further liquefied and rectified in the upper tower 4 to separate into nitrogen gas at the top of the upper tower and liquefied oxygen at the bottom of the upper tower, and from the middle stage of the upper tower 4 in the crude argon tower 5. The derived gas is liquefied and rectified to produce crude argon.

In the above crude argon column, a raw gas introduction pipe 6 and a liquefied gas return pipe 7 connected to the middle stage of the upper column 4 introduce the gas in the middle stage of the upper column 4 into the column, and a crude argon outlet pipe 8 in the upper part of the column. A crude argon condenser 9 is provided at the top of the column for liquefying the crude argon gas at the top of the column.

This crude argon condenser 9 is for condensing crude argon at the top of the crude argon column 5, that is, a gas concentrated to 90% or more of argon and the remaining oxygen and nitrogen. Liquefied air, which has been led out from the bottom of the pipe to the pipe 10 and passed through the supercooler 11 and the valve 12, is introduced as a cold source,
On the tube side, the crude argon is introduced from the upper part of the crude argon column 5 through the tube 13. The condensed and liquefied liquefied crude argon is returned from the pipe 14 to the upper part of the crude argon column 5 and becomes the reflux liquid of the column.

The liquefied air, which is the evaporation side fluid of the crude argon condenser 9, is partially vaporized and extracted from the pipe 15, and the liquefied air in the liquefied state is led out from the pipe 16.
Both are introduced into the upper middle part of the upper tower 4.

Here, since the tube side of the crude argon condenser 9 forms a closed cycle as is clear from the figure, the nitrogen gas which is the non-condensable gas must be discharged so that the condensation flow path in the condenser is May be filled with nitrogen gas, and eventually normal operation may not be continued.

Therefore, it is necessary to discharge a proper amount of nitrogen gas from the blow pipe 17, but if the flow rate of the nitrogen gas is increased, the inflow and outflow amounts of the pipe side fluid are increased to promote heat transfer. However, the liquid surface pulsates and the liquefied crude argon is discharged from this blow pipe 17, the recovery rate of argon decreases, and if the discharge amount of nitrogen gas is reduced, the nitrogen gas is concentrated in the condenser, An unstable phenomenon occurs due to a decrease in heat transfer performance and a change in condensation heat transfer amount.

Generally, in order to increase the amount of argon production, it is necessary to increase the yield of argon with respect to the raw material air, but in order to increase the yield of argon, argon in the raw material gas introduced into the lower part of the crude argon column 5 is used. If the concentration is increased, the concentration of nitrogen gas will also increase, and a large amount of non-condensable gas will flow into the crude argon condenser 9.

That is, the discharge amount of nitrogen gas which is the non-condensable gas of the crude argon condenser 9 needs to be an optimum amount according to the nitrogen content in the raw material gas. Even if the argon concentration in the inside is increased, the discharge amount of the non-condensable gas must be increased. Therefore, as described above, the non-condensable gas discharged from the blow pipe 17 is accompanied with the argon, and the production of argon can be increased. could not.

Therefore, the present invention is capable of reliably treating the non-condensable gas without waste of the desired component in the condensation evaporator in which the condensing side fluid containing the non-condensing gas is introduced into the condensing side like the above-mentioned crude argon condenser. It is an object of the present invention to provide a condensing evaporator and its system that can be recovered and can be operated stably.

[0012]

In order to achieve the above object, the condensation evaporator according to the present invention has, as a first structure, a condensing side fluid composed of a multi-component gas containing a non-condensable gas and a single side. In a condensing evaporator for exchanging heat with an evaporating fluid consisting of a component or multi-component liquid, a gas-liquid separating device is provided inside or outside the condensing evaporator on the outlet side of the condensing fluid, and the gas-liquid separating is performed. A discharge pipe for discharging the multi-component condensation-side fluid from the gas layer separated by the device is provided, and the discharge pipe is connected to a product gas system. As a second configuration, condensation is performed on the condensation-side fluid inlet side. A branch pipe for extracting a part of the side fluid is provided, and a vent pipe is provided on the outlet side of the condensing side fluid, and the vent pipe is provided on the downstream side of the pressure reducing valve provided on the branch pipe or an ejector provided on the branch pipe. Is characterized by being connected to .

[0013]

[Operation] With the above configuration, it is possible to prevent the non-condensed gas from staying in the condensing flow path, collect the target component without waste, and improve the performance of the condensation evaporator.

[0014]

EXAMPLES The present invention will be described below in more detail based on examples in which the present invention is applied to a crude argon condenser.

First, FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a system diagram of essential parts, and FIG. 2 is an explanatory diagram showing an example of a concrete structure.

In FIG. 1, a crude argon column 5 of an air liquefaction / separation apparatus having the same structure as the conventional one has a raw material gas introduction pipe 6 connected to the upper middle column and a liquefied gas return pipe 7 at the lower part of the column. A crude argon condenser 20 using liquefied air as a cold source is provided in the upper part of the tower.

In the crude argon condenser 20, the liquefied air at the bottom of the lower column is used as the evaporation side fluid in the tube 10,
It is introduced through the valve 12 and a part of it is vaporized into gas to form a pipe 15.
And derived from tube 16.

Crude argon, which is one of the fluids on the condensation side, is discharged from the top of the crude argon tower 5 through a pipe 13, and then is divided into two parts, and a part is branched through a branch pipe 41 and a pressure reducing valve 43 to collect product crude argon. Of the crude argon condenser 20 and is introduced into the condenser side of the heat exchanger 20a of the crude argon condenser 20. And
A gas-liquid separator 21 is provided on the outlet side of the condensing side fluid, and the liquid phase separated by the gas-liquid separator 21 is used as a reflux liquid from the pipe 22 to the top of the crude argon column 5 as described above. be introduced. The gas-liquid separator 21 may be provided inside the crude argon condenser 20 or outside the crude argon condenser 20.

The gas layer separated by the gas-liquid separator 21 is led out from the pipe 23. The gas led out from the pipe 23 is extracted as crude argon, and contains uncondensed gas that does not condense in the heat exchanger 20a of the crude argon condenser 20 as well as unevaporated argon and several% of oxygen. , To the pipe 44 of the product crude argon sampling system.

That is, as described above, the crude argon condenser 20 is used.
A gas-liquid separator 21 is provided on the outlet side of the fluid on the condensation side, and the gas layer separated by the gas-liquid separator 21 is replaced with crude argon gas instead of being led out from the top of the crude argon column 5 by a pipe 8. Since the crude argon gas containing the non-condensable gas can always be forced to flow to the outlet on the condensing side, it is possible to reliably remove the non-condensable gas to the outside of the condensing system by It can be kept constant and the crude argon condenser 20 can be operated in a stable state.

Further, by forcibly flowing the crude argon gas to the outlet on the condensation side, it is possible to reduce the film thickness of the condensed liquid on the surface of the condensation-side heat transfer surface, and the condensation heat transfer is promoted. It is also possible to reduce the size of the container 20.

FIG. 2 shows an example in which the above-mentioned structure is applied to a large-scale apparatus, and a core column 30 standing upright on the top of the crude argon column 5 of the condensation evaporator 31 provided on the top of the crude argon column. A plurality of heat exchangers 31a are arranged on the outer circumference of the condensate, and the condensing side outlet pipe 32 of each heat exchanger 31a is connected to the closed condensate reservoir 33 provided on the inner circumference of the core tower 30. Taking out liquefied crude argon from the pipe 34 under the reservoir 33,
Crude argon gas is extracted from a pipe 35 above the condensate reservoir 33 and is connected to a product crude argon sampling system to recover the crude argon gas as product crude argon gas.

FIGS. 3 to 5 show a second embodiment of the present invention, FIG. 3 is a system diagram of a main part, and FIGS. 4 and 5 are explanatory views showing a concrete structure example.

As shown in FIG. 3, the parent argon column condenser 40 shown in this embodiment has a branch pipe for introducing crude argon to the pipe 13 for introducing the crude argon gas, which is the fluid on the condensation side, into the heat exchanger 40a. 41 is provided, and a vent pipe 42 is provided on the outlet side of the condensation side fluid, and the vent pipe 42 is provided on the downstream side of the pressure reducing valve 43 provided on the branch pipe 41 or on the branch pipe 4
1 is connected to the ejector 53 (see FIG. 5). Since other configurations are the same as those of the conventional device, the same elements are denoted by the same reference numerals and detailed description thereof will be omitted.

With this structure also, the argon component conventionally discharged by being accompanied by the nitrogen gas discharged from the blow pipe 17 can be recovered in the crude argon discharged from the branch pipe 41. By increasing the amount of gas discharged from 42, it is possible to increase the flow rate of the condensation side fluid and accelerate heat transfer.

FIG. 4 shows an example in which the above-mentioned structure is applied to a large-scale apparatus. As in the case of FIG. 3, a condenser / evaporator 31 is provided at the top of the crude argon column 5 to provide a crude argon column. 5, a plurality of heat exchangers 31a are arranged on the outer periphery of the core tower 30 which is erected at the top of the core tower 5, and a branch pipe (crude argon outlet pipe) 50 is connected to the top of the core tower 30 and each heat exchanger 31a.
The condensing side outlet pipe 32 of No. 1 is connected to the condensate reservoir 33 provided on the inner circumference of the core column 30, the liquefied crude argon is taken out from the pipe 34 below the condensate reservoir 33, and the vent is connected to the upper part of the condensate reservoir 33. The crude argon gas containing the non-condensable gas is extracted from the pipe 51 and connected to the downstream side of the pressure reducing valve 52 provided in the branch pipe 50.

FIG. 5 shows a pressure reducing valve 5 provided on the branch pipe 50.
This is an example in which an ejector 53 is provided instead of 2. That is, the crude argon containing the non-condensable gas discharged from the vent pipe 51 is sucked by the ejector 53 and the branch pipe 50.
It is made to join the crude argon of.

In each of the examples, the derived crude argon contains a larger amount of non-condensed gas than before, but this non-condensed gas, mainly nitrogen gas, is used in the high purity argon column in the subsequent step. Since it can be separated by the rectification operation in (1), there is almost no problem, and the concentration of the non-condensable component can be made more stable and uniform than in the prior art, which also contributes to stable operation in the subsequent step.

In the above embodiment, the crude argon condenser is taken as an example of the condenser. However, as the condensing side fluid, various kinds of other condensing fluids containing the non-condensable gas as the condensing side fluid are used. The present invention can also be applied to a condenser, and in any case, stable operation of the condenser can be achieved by preventing the noncondensable gas from staying or concentrating in the condenser.

Further, although the condensing evaporator using the plate fin type heat exchanger is mentioned in the above-mentioned embodiment, it is also applicable to other types such as the condensing evaporator using the fixed tube plate type and the free-head type heat exchanger. can do. Further, the structure of the embodiment shown in FIG. 1 and the structure of the embodiment shown in FIG. 3 (including the ejector) may be used in combination.

[0031]

As described above, according to the condensing evaporator of the present invention, it is possible to prevent the non-condensable gas from staying in the condensing flow path, so that the condensation heat transfer amount is stabilized and the condensation heat transfer is promoted. Along with stable operation of the condensation evaporator, downsizing can be achieved,
The product gas yield can be improved.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a similar concrete structure.

FIG. 3 is a system diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an example of a similar concrete structure.

FIG. 5 is an explanatory diagram showing another example of the same concrete structure.

FIG. 6 is a system diagram showing an example of a general air liquefaction separation device.

[Explanation of symbols]

5 ... Coarse Argon Tower 20,40 ... Coarse Argon Condenser
21 ... Gas-liquid separator 41 ... Branch pipe 42 ... Vent pipe 43, 52 ... Pressure reducing valve 53 ... Ejector

Claims (2)

[Claims] 1. A condensing evaporator and its system for exchanging heat between a condensing side fluid composed of a multi-component gas containing a non-condensing gas and an evaporating side fluid consisting of a liquid of a single component or a multi-component system, A gas-liquid separator is provided on the outlet side of the condensing side fluid, and a lead-out pipe for leading out the multi-component condensing-side fluid from the gas layer separated by the gas-liquid separator is provided, and the lead-out pipe is connected to the product gas system. A condensation evaporator and its system characterized by the above. 2. A condensing evaporator and its system for exchanging heat between a condensing side fluid composed of a multi-component gas containing a non-condensing gas and an evaporating side fluid consisting of a liquid of a single component or a multi-component system, A branch pipe for extracting a part of the condensation-side fluid is provided on the inlet side of the condensation-side fluid, and a vent pipe is provided on the outlet side of the condensation-side fluid, and the vent pipe is provided on the downstream side of the pressure reducing valve provided on the branch pipe or Condensation evaporator and its system connected to an ejector.