The invention relates to a piping system for use in tanks carrying cryogenic products.

The invention particularly relates to a piping system comprising a central pipe which compiles gas transfer pipes in the region wherein contact with cryogenic liquid will occur, intended to prevent the gas transfer pipes, through which gas phase product is carried, from contacting with cryogenic liquid and insulation pieces located between the said pipes, aimed at minimizing heat exchange.

STATE OF THE ART

Cryogenic tanks are utilized to carry and store liquid phase gases; liquefied natural gas (LNG), liquefied nitrogen, liquefied argon, liquefied oxygen. In addition to the cryogenic liquid at a minimum temperature of -196 °C within the tank, 5% gas phase (LNG) and 2% air gas are included in the said tank to operate safely. This ratio is %2 for inflammable products (Nitrogen, Argon, etc.), and 5% for inflammable ones (LNG etc.). Forms of the piping system and the pressure tank are of great importance for the said products in gas and liquid forms to be carried and stored effectually.

In the tanks of the state of the art, pipes which carry gas phase products pass through the liquid phase. This contact of pipes carrying gas phase products results in heat exchange between the said liquid and gas two phases. Due to this undesired heat transfer, gas in the pipe liquefies by condensation and substances in the said gas phase are not able to discharge from the tank effectually. However, pipes with products in gas phase in cryogenic tanks must protrude out from the shortest route and without contacting the liquid phase to prevent the heat leakage that can create condensation of gas inside safety lines

As a result, there is need for an innovation and an improvement in the related field due to the aforementioned disadvantages and the insufficiency of present solutions about the subject. OBJECTS OF THE INVENTION The present invention relates to a piping system to be used in tanks which carry cryogenic products to eliminate the aforementioned disadvantages and to bring new advantages to the relevant technical field. Primary object of the invention is to provide a piping system which prevents heat exchange between products carried in gas phase and liquid phase in cryogenic tanks. Thereby, back condensation is prevented and discharge of the gas is performed without any problems.

Another object of the invention is to provide a cryogenic tank piping system allowing the discharge of the gas carried in the pipes through the shortest route. The pressure of the gas present within the tank needs to be lower than the set pressure of the release valve. Therefore, discharge of the gas in the pipes through the shortest route is of importance due to limited 3% pressure drop. Another object of the invention is to provide a piping system which carries the pipes, carrying gas phase products, without contacting them directly to the liquid, by collecting the said pipes in a central pipe where the contact with the liquid is expected. Thereby, without any direct contact with the liquid, the risk of condensation is prevented. With the invention, it is intended to provide a piping system with less pressure drop. With the piping system provided by the invention, gas is transferred directly to safety valves.

In the invention, insulation pieces located between pipes decrease back condensation by reducing heat exchange.

The structural and characteristic features and all the advantages of the invention will be clearly comprehensible by means of the following figures and the detailed description written by referring to those figures and thereby the assessment should be made by considering these figures and the detailed description.

FIGURES THAT WILL HELP UNDERSTANDING OF THE INVENTION

In Figure 1 , is given a schematic view of the cryogenic tank in the state of the art.

In Figure 2, is given the view of the cryogenic tank of the invention.

In Figure 3, is given the view of part of the cryogenic tank of the invention.

In Figure 4, is given a zoomed cross-sectional view of the central pipe included in the cryogenic tank of the invention. REFERENCE NUMBERS

S Piping System

1 Cryogenic Tank

2 Cryogenic Tank Interior

3 Cryogenic Liquid

4 Gas Transfer Pipes

5 Pipe Weld Housing

6 Insulation Piece

7 Central Pipe

DETAILED DESCRIPTION OF THE INVENTION In this detailed description, the preferred embodiments of the invention is described only for the purpose of better understanding and without inserting any restrictive effects.

The piping system (S) of the invention comprises a central pipe (7), which compiles gas transfer pipes (4) carrying gas phase products within a cryogenic tank (1 ) carrying cryogenic liquid, in the region wherein contact with cryogenic liquid will occur, intended to prevent gas transfer pipes (4), through which gas phase product is carried, from contacting with cryogenic liquid and multiple insulation pieces (6) located between the said gas transfer pipes (4) and central pipe(7), aimed at minimizing heat exchange, a weld housing (5) located in the area wherein gas transfer pipes (4) are connected to the central pipe (7).

The said cryogenic liquid comprises of substances such as liquefied low temperature natural gas (LNG), Nitrogen (LIN), Argon (LAR) and Oxygen (LOX).

Gas transfer pipes (4) are pipes which carry gas phase fluids. Part of the said gas transfer pipes (4) are located within a central pipe (7) insulated from the cryogenic liquid, whereas the rest is located in the cryogenic tank interior (2) outside the central pipe (7). However, because gas transfer pipes (4) which are not located within the central pipe (7) are placed on the upper parts of the cryogenic tank (1 ), contact with the cryogenic liquid does not occur. Pipe weld housing (5) is the piece which ensures welding and stabilization of the gas transfer pipes (4) on the central pipe (7). The central pipe (7) is the structure which is in a vertical position according to the base of the cryogenic tank (1 ) within the cryogenic tank (1 ). Within the said central pipe (7) whose outer surface is in contact with the cryogenic liquid, are located multiple gas transfer pipes (4) whose contact with one another and with the said central pipe (7) are prevented. Gas transfer pipes (4) which carry gas phase products inside do not contact with the cryogenic liquid thanks to the central pipe (7).

The element which is aimed at preventing the gas transfer pipes (4) from contacting with one another and the central pipe (7) is the insulation piece (6). Said insulation piece (6) is constrained between the gas transfer pipes (4) so as to prevent the said gas transfer pipes (4) from contacting with one another. Similarly, insulation piece (6) is placed between the gas transfer pipes (4) and the inner surface of the central pipe (7). Thereby, heat exchange of the gas transfer pipes (4) between one another and the central pipe (7) is prevented. Another aim of the said insulation piece (6) is to stabilize the said gas transfer pipes (4). In this sense, mechanical support to the piping system (S) is provided. In the invention, non-metal insulation pieces (6) can be utilized.

Cryogenic liquid within the cryogenic tank interior (2) at a minimum temperature of -196 °C evaporated depending on the amount of the temperature entering the cryogenic tank (1 ) and transforms into gas phase. There is a volume in cryogenic tanks (1 ) reserved for these liquids to evaporate and expand safely. Said volume must be discharged according to the conditions of the process and mechanical calculations. Pressure of the gas within the cryogenic tank (1 ) may be equal to the set pressure of the safety valve to be utilized in the maximum discharge.

The length and the diameter of the gas transfer pipes (4) utilized in the piping system of the invention must be chosen to prevent a pressure drop of 3%. Said gas transfer pipes (4) must be filled with pure gas as they transmits the stored energy to the safety valve, otherwise they can be obstructed by the liquid phase cryogenic liquid entering into the pipes or the gas which condensates in the gas transfer pipes (4). This prevents the discharge of the cryogenic tank.