DE3303420A1 - Process and device for purifying the respiration air in an underwater habitat by removal of CO2 - Google Patents

Abstract

The invention relates to a process and devices for carrying out the process for purifying the gas in an underwater habitat by removing CO2. The installation for the in-situ sorption/desorption inside a habitat 1 located underwater is diagrammatically shown in Figure 1. The CO2 produced in the habitat 1 is pumped by means of a pump 2 via a line 3 to at least two adsorbers 4 and 5 (molecular sieves) which can be connected parallel to one another, and from there back into the habitat 1. The pressure build-up of a regenerated adsorber 4 or 5 is carried out initially via a pressure balance line 6 with a valve 7 from the other adsorber at the time, which is then to be regenerated. The remaining pressure is generated by supplying purified fresh gas via the line 8 or 8' and 8'' with the valves 9 and 9'. <IMAGE>

Description

Method and device for cleaning

of the breathing gas in an underwater habitat from CO2 Description: The invention relates to a method and devices for carrying out the method for cleaning the gas in an underwater habitat from C02.

The amounts of carbon dioxide accumulating in diving chambers in the respective The diver's breathing gas can be removed by various methods. The most common are absorption materials (soda lime, baralyme) and metal hydroxides. These are consumables that are especially important for longer dives in habitats still transported to the depths and consumed to the surface of the water Need to become. In addition, the corresponding process facilities are in the interior of the chambers, in which there is not much space anyway.

A well-known separation process for the separation of CO from the Breathing gas forms the adsorption process with molecular sieves (e.g. 5X or 13X). It however, it was never used underwater because the regeneration of the Adsorbers by increasing the temperature (4t approx. 2500) has to be carried out, a process which inevitably leads to difficulties in underwater use. The same goes for for the use of pressure swing adsorption systems, which on land is the state of the Technology counts, but not considered for underwater applications became.

The object on which the invention is based now consists in Find a process and facilities to do this in a habitat Breathing or welding or through (other) combustion processes (like diesel engine) the resulting C02 can be eliminated in situ.

The solution to this problem is in the characterizing features of the Claim 1 described, while the remaining claims have advantageous facilities reproduce for the implementation of the inventive idea.

The invention is illustrated below with reference to FIGS. 1-3 and with reference to two Embodiments described in more detail.

The facility for in situ sorption / desorption within a sub Habitat 1 lying in the water is shown schematically in FIG. 1. That in the habitat 1 C02 produced is converted into at least two by means of a pump 2 via a line 3 Adsorbers 4 and 5 (molecular sieves) that can be switched parallel to one another and from there pumped back into habitat 1. The pressure build-up of a regenerated adsorber 4 or 5 takes place initially via a pressure equalization line 6 with valve 7 from each another adsorber, which is then to be regenerated.

The remaining pressure is obtained by switching on purified fresh gas Generated via the line 8 or 8 'and 8' 'with the valves 9 and 9'. The one right now The ready-to-operate adsorber is now off with the breathing gas the habitat 1 flows through under operating pressure. If a suitable molecular sieve is selected Carbon dioxide and possibly water vapor are adsorbed and thus from the air we breathe removed. Shortly before the breakthrough point for carbon dioxide is reached, over Purified gas flow over the expansion line 6 until it is equalized. The last Pressure drop (e.g.

from operating pressure 30 bar to desorption pressure 15 bar) is blown off of the gas via a long filled hose 10, which has a differential pressure p granted.

The pressure swing adsorption process used here is thus Can be used for underwater areas without the need for voluminous expansion tanks and compressors are necessary. The vented breathing gas is replaced by the same amount of fresh gas. The switching of the valves contained in the supply and discharge lines can be electronic controlled.

Process modifications, such as purging with clean gas, increase the number of containers to 3 (or a multiple of 2 or 3 in the case of larger sales) for the rinsing process are possible and require optimization in the application.

The gas to be continued can be transported over the 150 m long, through a Float 11 (see Fig. 2) above habitat 1 and below the water surface 12 held hose 10 or with a hose 13 (see Fig. 3 in the umbilical to the surface of the water 12 to the supply ship 14 removed will. The pressure difference tp is then correspondingly larger and the contaminated However, gas can be fed to the He cleaning system via a compressor and high-pressure cylinders.

Numerical example: The numbers are only indicative, the physical ones Data on the zeolites that can be used as molecular sieves must be determined in each case.

Assuming CO2 production 600 l / h = 1.18 kg / h (4 tanchers with max 2.5 1 / min in the habitat 1) The amount of gas circulated with pump 2 is 80 m3 / h assumed, so that with a container diameter of the adsorber 4, 5 of 300 mm results in a flow velocity (empty) of 0.31 m / s.

The maximum C02 concentration is assumed to be 0.1 vol%, which is at a diving depth of 300 m corresponds to a partial pressure of approx. 0.03 bar. Per 100 Approximately 5 g of C02 are then absorbed.

The exact values must be tested in each case. They are dependent on, among other things the adsorber temperature, the gas humidity and the pressure drop at the Desorption.

In the case of an hourly switching cycle, this results in taking into account the LUB an amount of zeolite of about 34 kg per adsorber 4, 5 corresponding to 50 1 and so one Dumping height of 70 cm. The loss gas occurs per hour approximately with a container content of 80 1 at a depth of 300 m, 1.2 Nm3 breathing gas is generated, when using Purge gas accordingly more.

Without purging gas, that which is blown off would correspond to the surface of the water 12 breathing gas to be transported for recovery so only 1.5% of the circulated Amount of gas.

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Claims (6)

Claims: 1. Method for cleaning the gas in an underwater habitat of CO2, characterized in that the consumed gas for the sorption of CO2 through an adsorber (4 or 5) is performed and that for desorption of the CO2 from the adsorber (4 or 5) the pressure swing method is used, in which the hydrostatic Pressure difference #p p between habitat (1) or adsorber (4, 5) and a place between Habitat (1) and the water surface (12) is exploited. 2. Device for performing the method according to claim 1, characterized characterized in that at least two adsorbers (4,5) lying parallel to one another are switched on alternately in the gas circuit (3), and that the adsorbers (4, 5) both with each other via a pressure equalization line (6) and with a fresh gas and a blow-off line (lo) can be connected. 3. Device according to claim 2, characterized in that a floating body keeps the blow-off line (10) above the habitat (1) in the water. 4. Device according to claim 2, characterized in that the blow-off line (lo) to the surface of the water (12) to a supply ship (14) is performed. 5. Device according to claim 4, characterized in that for the Laying the blow-off line (10) the umbilical (13) can be used. 6. Device according to claim 2 or one of the following, characterized in that that the adsorbers (4, 5) are molecular sieves.