FI91625C - Tank for environmentally harmful liquids - Google Patents

Description

91625 5 Storage of environmentally harmful liquids Behållare for miljofarliga våtskor

The invention relates to the storage of liquids harmful to the environment. More specifically, the invention relates to a double-jacketed silo from which the entry of liquids harmful to the environment into the environment due to silk leaks is prevented.

10 The storage of many environmentally harmful liquids in above-ground or underground storage tanks is a problem. When a tank breaks out, for example due to corrosion, the contents of the tank can leak into the environment and, for example, contaminate groundwater. Often, and especially in underground silos, leaks are only detected after a long period of time, when considerable amounts of harmful substances can escape and contaminate the environment and groundwater.

It is known to use double-shelled tanks, for example for the storage of fuels and chemicals, and in some areas other types of tanks are not permitted. It is also known to fill the space between the jackets with a mixture of ethylene glycol and water which is pressurized or hydrostatically pressurized by means of an expansion tank. If the inner jacket or outer jacket ruptures, this is detected as a change in pressure or a change in the level of the liquid in the expansion tank.

However, the use of glycol is harmful in itself. When the outer casing breaks out, it gets into 25 soils, from which it is difficult to remove. Glycol is water-soluble and therefore spreads quickly over a wide area, making it difficult and expensive to remove.

When the inner jacket bursts, water and glycol get into the liquid to be stored, which causes contamination of the contents of the container. Even a small amount of glycol, for example in petrol, diesel, light fuel oil, causes serious dirt, running and scaling problems in engines and oil burners. The glycol-water mixture also causes corrosion of the silo shells. The corrosion inhibitors necessary to prevent corrosion further increase the toxicity of the mixture.

Thus, there is a need for double-shelled silos in which the protective liquid used does not have the above-mentioned disadvantages. The above-mentioned problems have been solved in the container according to the invention.

The invention thus relates to a container for storing liquids which are harmful to the environment, having at least a partial double jacket and in which the space between the jackets contains a liquid. The silo according to the invention is characterized in that a liquid is used as the liquid in the space between the diapers, which has the following properties: (a) is harmless to the environment when it comes outside the silo; and 10 (b) is harmless to the product in the container itself.

The fluid used must be safe for the environment, so that no problems of contamination and destruction arise due to the possible rupture of the outer casing. The most desirable are those liquids which decompose spontaneously as a result of natural decomposition activities, so that separate collection and destruction is not required, even in small spills.

Another requirement for the liquid used is that it does not cause any harm to the liquid stored in the container if the inner shell ruptures. This means that the liquid used does not, in a reasonably small amount, interfere with the use of the product to be stored for its original purpose. For example, in the case of petrol or diesel, this means that the fluid used does not cause a reasonable amount of problems in engine operation.

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Liquids that meet the above requirements are certain biodegradable liquids which, by their nature, decompose spontaneously under the influence of bacterial activity. Certain substances of natural origin, such as various vegetable oils and their esters, are particularly suitable. Ordinary alcohols such as methanol and ethanol are also suitable. Some synthetic esters, such as biodegradable esters used as lubricants, are also suitable.

30 The above liquids also do not cause poisoning or contamination problems for the liquid stored in the container.

Examples of suitable liquids for use in the containers according to the invention are thus

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3 91625 Vegetable oils or esters of vegetable oils, petroleum esters, alcohols and synthetic biodegradable lubricating oils. Particularly suitable are e.g. rape, colza, soybean or sunflower oil or their esters, and pine oil ester.

5 For example, rapeseed oil ester has a pour point of about -30 ° C, which is a sufficiently low value for underground canning. Rapeseed oil has a flash point above 100 ° C, so its fire class is not a problem. The inclusion of rapeseed ester in the fuel is not detrimental, but rather advantageous. For example, the smoke and particulate emissions of a diesel engine are further reduced by mixing rapeseed oil ester with diesel oil. Rapeseed oil ester mydskåån 10 does not cause corrosion problems. The other liquids listed above also have at least partially similar properties.

The container according to the invention has at least a partial double jacket. Thus, the double jacket does not have to encircle the entire container, but the container may have a simple wall in those parts which are not in contact with the liquid to be stored. Thus, the upper part of the silo may have a normal structure, but the wall below and on the sides is double.

Methods and equipment known per se can be used to detect leakage. An Eras way to detect a leak is to maintain an overpressure in the space between the double walls. 20 The system may include an alarm when the pressure drops in the space between the walls. Another more common way is to use an expansion tank and a surface sensor.

The container according to the invention can be applied both as an above-ground container and as an underground container. Particularly in the case of an underground silo, the advantages of the invention are obvious, since expensive and large-scale soil cleaning is avoided and it is not necessary to build an expensive lining under and around the silo, for example a concrete trough.

The container according to the invention is suitable for the storage of all kinds of toxic and environmentally harmful liquids. Such fluids include fuels such as gasoline, diesel and fuel oil, solvents, lubricating oils, and other toxic chemicals.

Claims (7)

1. Container for storage of environmentally hazardous liquids with at least a partial double mantle, where the space between the mantles contains liquid, characterized therefrom, that as the liquid 5. the space between the mantles is used a liquid with the following properties: (a) outside the container; and (b) is harmless to the product stored in the container. 10 2. Container according to claim 1, characterized in that said liquid is biodegradable. Container according to claim 1 or 2, characterized in that said liquid is selected from the group of plant oils or esters of vegetable or tall oil, alcohols or synthetic biodegradable lubricating oils. Container according to claim 3, characterized in that said liquid is rapeseed oil, soybean oil or sunflower oil or esters thereof. 5. Container according to any one of the preceding claims, characterized in that it is equipped with means for detecting leakage in the inner and / or outer wall. Container according to one of the preceding claims, characterized in that the space between the mantles is under pressure. 25 Use of the container according to any of the preceding claims as an underground or above ground container for fuel, chemicals or solvents.