JPS6044243B2 - Method for producing oxygen-enriched gas using steam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing oxygen-enriched gas that can be used for wastewater treatment, combustion supporting gas for combustion furnaces, etc. by using steam.

Methods for producing oxygen-enriched gas include obtaining liquid oxygen by cryogenic separation and adsorption separation using zeolite I, but both have the disadvantage that the equipment, space, and cost are extremely large. be.

Therefore, in recent years, organic thin films such as organopolyzolone xane and silicone rubber have been formed, and by applying a pressure difference between the front and back sides of the film, air can pass through this organic thin film. Diaphragm-type air separation devices are also being used that extract oxygen-enriched gas from the passage side by utilizing the difference in gas permeation rate at different times; Therefore, it does not fundamentally solve the above-mentioned problems.

On the other hand, in industrial areas with large-scale blast furnaces, melting furnaces, and combustion furnaces, and in places where industrial wastewater is treated, there is an abundance of waste heat from large amounts of generated gas and associated steam, but many of these Since this surplus energy is being dissipated in vain, research into the recovery and use of this surplus energy has been particularly active recently.

However, the results were that the generated gas itself was introduced into a gas turbine to generate electricity and use it as electrical energy.
Waste heat is used to generate steam and a steam turbine is used to generate electricity, and in both cases, the efficiency is poor and unsatisfactory as it is converted into electrical energy and then used as electricity.

The present invention makes it possible to produce oxygen-enriched gas without using a separate power source by utilizing energy that is not effectively utilized and is wasted without being recovered, thereby saving energy. The aim is to achieve both effective utilization and improvement of the enriched gas production method, and the details will be explained below in detail with reference to the drawings.

As mentioned above, the diaphragm type air separation device 1 has an organic thin film made of silicone rubber or the like, and its front side faces the outside air 2, and its back side is connected to the inlet 4 of a steam ejector 3 called a steam vacuum pump or the like. , the steam 6 generated from surplus steam and waste heat generated in the industrial area as described above is supplied from the inlet 5 of the same industrial sector 3, and is allowed to flow through the outlet 7. In the figure, 8 indicates a drain separator provided on the way out, and 9 indicates the cooling water.

Therefore, in the case of Fig. 1, if the steam 6 is supplied and passed through the steam ejector 3 as described above, the steam flow causes the suction port 4 side to be in a depressurized state, and even if the same sector has only one stage, a vacuum of about 100 torr is created. Due to the pressure difference between this negative pressure and atmospheric pressure, air enters toward the steam ejector 3 side, which makes it possible to extract the oxygen-enriched gas 10 from the back side of the device 1. In fact, as mentioned above, it was possible to obtain the same enriched gas with an oxygen gas concentration of 40% at 15 i/h1 using only one stage.

As a result, a mixed gas 11 of water vapor and oxygen-enriched gas is discharged from the same sector 3. In this case, if necessary, the water vapor can be removed by providing a drain separator 8 as shown. The water may be sent to the demand destination 12 to which it should be supplied, but if the demand destination 12 is a wastewater treatment tank, for example, the drain separator 8 is not provided and the pipes are directly connected between the same sector 3 and the demand destination 12. In this case, if the piping is appropriately long, the temperature at the inlet of the wastewater treatment tank can be set to a level that does not affect the treatment. Next, in the example shown in FIG. 2, 13 is a blast furnace;
In a furnace such as a melting furnace or a combustion furnace, steam is generated by the high-temperature waste gas of the furnace 13, and this is introduced into the inlet 5 of the steam ejector 3, and the outlet 7 of the sector 3 is connected to the A closed circuit is shown by connecting the combustion supporting gas supply point as the demand destination 12 in the furnace 13, and in this case, the mixed gas 11 discharged from the outlet 7 of the steam ejector 3 The water vapor inside is condensed by the drain separator 8 and discharged outside the separator 8, and only the oxygen-enriched gas is blown into the furnace 13 as a combustion supporting gas. Water vapor obtained using heat is sent to the steam ejector 3. In this case, when steam with a pressure of 7k9/CriG was actually supplied to the steam ejector 3 at 160k9 per hour from the steam generator (not shown) of the furnace 13,
The degree of vacuum at the intake port 4 of the same sector 3 is 70 to 100.
40% oxygen-enriched gas can be obtained by the diaphragm air separation device 1 at a rate of 15 per hour, and the outlet 7
By removing water vapor from the mixed gas 11 using the drain separator 8, 40% oxygen-enriched gas having a relative humidity of approximately 50% can be blown into the furnace 13 as combustion supporting gas for 15 d per hour as described above. did it.

Since the present invention can be realized as described above, it is possible to directly utilize waste heat and surplus steam generated in large quantities in factories, etc., and to utilize the steam without using additional power when producing oxygen-enriched gas. Since the same gas can be obtained, the cost can be significantly reduced compared to the conventional method in which high-purity oxygen is mixed with air and used as combustion supporting gas for the furnace. The purpose can be achieved by a new configuration of connecting the separation device and the steam ejector.
This also solves the problems of the conventional method in terms of equipment and location.

[Brief explanation of the drawing]

FIG. 1 is a system explanatory diagram showing one embodiment of the apparatus that can be used for producing oxygen-enriched gas according to the present invention, and FIG. 2 is a system explanatory diagram showing another embodiment of the same apparatus. 1...Diaphragm type air separation device, 2...Outside air, 3...Steam ejector, 6...Water vapor, 10...Oxygen enrichment Gas, 12...
・Demand destination.

Claims (1)

[Claims] 1. By supplying and passing water vapor such as surplus steam to a steam ejector, a reduced pressure state is created in the ejector, and due to the pressure difference between the resulting negative pressure and the outside air, the outside air is removed from the ejector. The oxygen-enriched gas extracted by the connected diaphragm type air separation device flows out from the ejector together with the water vapor, and the mixed gas is separated from the water vapor as necessary to meet the desired demand. A method for producing oxygen-enriched gas using steam, characterized in that the gas is discharged first. 2 Steam generated by a furnace such as a melting furnace is supplied to a steam ejector and passed through, the steam is separated from the mixed gas flowing out from the ejector, and the oxygen-enriched gas obtained thereby is used as a support for the furnace. 2. A method for producing oxygen-enriched gas using steam according to claim 1, characterized in that the steam is discharged to a fuel gas supply location.