Ammonia Tank Drainage System

Abstract

The invention relates to a system for the controlled discharge of liquid ammonia remaining below the pump suction nozzle in a cryogenic anhydrous ammonia storage tank with a storage capacity of 25,000 tons of liquid ammonia and without a drainage line, in order to ensure tank and environmental safety.

Description

1 TARIFF AMMONIA TANK DRAINAGE SYSTEM Technical Area The invention is a system with a storage capacity of 25,000 tons of liquid ammonia without a drainage line. In a cryogenic anhydrous ammonia storage tank; the liquid remaining below the pump suction nozzle. controlled release of ammonia for tank and environmental safety It is related to a system. 5 State of the Art Large-capacity liquid ammonia storage tanks used in industry are typically double-layered. It is designed with a double-walled structure. Liquid ammonia is placed in the inner wall, and ammonia gas in the outer wall. Literature research has revealed that there are two types of cryogenic liquids used in industry. There is an ammonia storage tank. The first of these is the periodic maintenance of the tank 10 In the event of an emergency or other situation, the liquid ammonia inside the tank must be completely and safely removed. and a drain line located at the bottom of the tank for rapid evacuation. They are tanks. Another type of tank does not have a drain line for complete emptying of the tank. This is version 15. In this type of tank, the discharge of the liquid remaining under the pump suction nozzle is required. That is not possible. The ammonia tank in question has an inner diameter of 46 µm. Liquid ammonia... The density of ammonia at the temperature at which it is stored is 682 kg / m3. Therefore, at a depth of 1 meter... It is known that 1129 tons of ammonia were stored. This design is advantageous in terms of both safety and heat. It is preferred in order to prevent losses. These tanks have a storage capacity of tens of thousands of tons of liquid ammonia and can withstand temperatures as low as -35°C. It is designed to operate at temperatures between +50 °C and high flow rates. Loading can be done from ships. The pump suction nozzles of the tanks are located at a certain distance from the bottom. It is positioned at a certain height. In the current system, the pumps that draw suction from the tank are centrifugal. These are centrifugal pumps. Centrifugal pumps do not create a vacuum and suck up gaseous ammonia. These are pump types that enter cavitation very quickly upon arrival. Therefore, the existing 25 It is theoretically impossible to empty the tank using system pumps. A peristaltic pump test was conducted to create a strong vacuum during tank emptying. However, since ammonia gasifies much more under vacuum, the peristaltic pump constantly 2 It carries both gaseous and liquid forms together. Simultaneous transport of gaseous and liquid forms. This creates serious blows to the transfer lines. These blows are known as coach strokes. It is characterized as a disruption of integrity in transfer lines as a result of a coaching coup. The release of a hazardous fluid like ammonia into the environment constitutes an environmental accident. Therefore, transferring ammonia using a vacuum system is not possible. The current 5 The pumps can draw liquid up to a level of 1432 mm. However, below this level... The design does not include any bottom drain line to remove the remaining liquid. Therefore, it is not possible to completely empty the tank, and there are 1600 tons of liquid in the bottom section. Ammonia always remains. Currently, liquid ammonia remaining below the pump suction point very quickly turns into gas phase 10 Because it passes through, it causes cavitation in the pump, and fluid cannot be extracted from that area. This is especially true for large-capacity tanks of this type (for example, a large-volume tank with a diameter of 46 m). (In the tank) a level below 1432 mm corresponds to approximately 1600 tons of liquid ammonia. This Since the quantity cannot be measured directly, the ammonia in the tank will decrease by mass over time, only once a day. 0.05% is removed by gasification. However, this method will take months in practice. This requires a lengthy operation. This affects business continuity, safety, and cost. This creates serious disadvantages in this respect. The need to empty large-capacity liquid ammonia tanks only occurs during operation. It is not limited to the requirements. Surface conditions stipulated under the API 653 standard. During storage tank inspections, the tank is checked for periodic maintenance and inspection every 10 years. It needs to be completely emptied, purged with inert gas, and ventilated. This During the processes, the internal environment of the tank must be made completely safe, ammonia It is essential to remove the debris and provide suitable working conditions. Ammonia's pungent odor and suffocating nature make it difficult to breathe, even at low concentrations. Because it causes serious irritation to the airways and eyes, an additional 25 is used in drainage procedures. Risks exist. Therefore, completely emptying the tank is crucial for both operational continuity. Moreover, it emerges as a critical requirement in terms of health and safety. In the current system, patent / utility model applications and articles related to the subject matter. Application number "CN112299444A" is currently in the known state of the art. It relates to a mobile and portable liquid ammonia recovery and tank emptying system. 30 The system includes an ammonia tank, a soft water tank, a liquid ammonia storage tank, pumps, and more. a number of ball valves, a compressor for pressurizing the gas phase, a tank truck or 3 Metal hose used for connecting to the storage tank, as well as for filters, dryers, and solid waste. It consists of units for recycling. The utility model application numbered “CN202237728U” exists in the prior art. It is concerned with the safe discharge and recovery of ammonia-containing waste gases. The system; recovery It consists of a recovery tank, a washing tank, an absorption tank, and a secondary absorption tank. 5 The gases, which are released from the tank due to increased pressure, are passed through these units in sequence. Impurities and some ammonia are dissolved in the washing tank. In the absorption tank... Most of the ammonia is absorbed into the water, resulting in pure and high-quality ammonia water. The secondary absorption vessel then captures the remaining small amount of ammonia, preventing its release into the atmosphere. It prevents. 10 “Ammonia storage tanks decommissioning” in the known state of the art. The article titled "consultants" describes the process of decommissioning ammonia storage tanks. It is explained that the main purpose is to safely store ammonia in both liquid and gaseous phases inside the tank. The process involves draining the liquid ammonia from the tank. First, the liquid ammonia in the tank is transferred to another location using pumps or pressure. It is transferred to a storage or purification system. The gas phase remaining at the top is flake or 15 It is directed to the absorption system. Then, an inert gas (mostly nitrogen) is injected. The tank atmosphere is purged and the ammonia concentration is reduced to safe levels. The residues are reduced. If necessary, the tank is washed with water or neutral solutions; the residues are then removed. It is being taken to the next phase and purified. As a result of these processes, the tank is completely emptied and made safe. It has been prepared and is ready for decommissioning. 20 Current systems have some significant limitations. For example, large volumes of liquid In ammonia storage tanks, the pump suction point is above a certain level. Because of its positioning, the liquid portion below this level is drained directly. This is not possible. This situation is referred to as "dead volume" at the bottom of the tank and is a classic problem. This leads to a significant amount of liquid ammonia remaining that cannot be removed by these methods. 25 Another problem arises when trying to remove the liquid that remains below the pump's suction point. This is when the liquid rapidly transitions to the gas phase, causing cavitation in the pump. This situation makes evacuation impossible and increases the risk of equipment failure. Additionally, the liquid below this level evaporates on its own from the tank. Because it needs to be heated slowly for insulation and for the process to be safe, it's quite 30. It takes a long time, and the tank emptying process can last for months. 4 The gas recovery solutions or absorption-based solutions envisioned in current systems The methods essentially involve the safe disposal of ammonia in the gaseous phase. It focuses on providing an effective solution for the complete drainage of the liquid remaining at the bottom of the tank. It does not offer. Similarly, with inert gas applied in decommissioning procedures. Although purging or flushing methods help remove residue, pump 5 Enables direct extraction of large quantities of liquid below the suction point. He does not know. In conclusion, the technical limitations described above and the inadequacy of existing solutions Therefore, the liquid ammonia remaining below the pump suction point can be safely, quickly, and controllably removed. A system is needed that will allow for evacuation in this manner. 10 Brief Description and Objectives of the Invention The invention addresses the shortcomings of the existing system while meeting all the requirements mentioned above. and eliminates the disadvantages, ensuring the safe retention of liquid ammonia below the pump suction point. The invention relates to a system for controlled evacuation. Specifically, the invention concerns: A drain line with an addable hose and pump connection can be connected to the tank base at 15 by allowing the remaining fluid to be directly removed, which is not possible in classical systems. It performs the complete emptying process safely and quickly. The purpose of the invention is to safely remove the material below the pump suction point in existing systems. liquid ammonia that cannot be drained is removed via a special drain line and hose-pump connection. The goal is to ensure that it is taken directly outside using [method]. 20 Another aim of the invention is to make it possible to completely empty the tank, thus saving time. To shorten evacuation time and reduce costs without the need for gasification or risky operations. The aim is to ensure controlled descent of the remaining liquid and increase operational safety. Furthermore, the invention allows for the controlled descent of the remaining liquid. By taking this into consideration, harmful emissions and ammonia losses are reduced. It aims to contribute to its prevention. 25 Explanation of the Figures Figure 1: View of the discharge system connected to the ammonia tank. Figure 2: Detailed view of the drainage system. Element Numbers in the Figures To better explain the evacuation system developed with this invention, the figures are shown. The parts and components are numbered, and the corresponding information for each number is given below: 1. Ammonia tank 2. Tank outlet pipe 3. Tank outlet valve 5 4. Hose 5. Gasket group 6. Blind flange 7. Pulley 8. Connecting pulley 10 9. Ball valve 10. Separator inlet line 11. Separator 12. Pump suction line 13. Pump 15 14. Pump discharge line 15. Gas supply line to the chimney 16. Chimney Detailed Description of the Invention The invention describes the safe and rapid operation of liquid ammonia tanks (1) without a drain line. It relates to a drainage system that enables evacuation. The drainage system that is the subject of the invention, The liquid remaining below the pump suction point in the liquid ammonia tank (1) must be safe. It is designed to allow it to be taken out in this way. The discharge system consists of a 12-inch blind flange (6) mounted on the end of the tank outlet pipe (2), the blind flange (6) reel welded to the center (7), hose (4) passed through reel (7), hose 25 The gasket assembly (5) that provides the seal between (4) and the blind flange (6) is attached to the end of the hose (4). 3 inch ball valve (9) connected, separator inlet line after ball valve (9) (10), separator (11) and pump suction line providing liquid flow from separator to pump (13) (12) includes the chimney outlet line (15) and the chimney (16) which performs the gas discharge. The working principle of the discharge system is as follows: firstly, the liquid ammonia tank (1) pump suction 30 The nozzle is cut and a 12-inch blind flange (6) is welded onto it. The blind flange (6) The reel (7) placed in the middle securely fits the hose (4) into the liquid ammonia tank (1). 6 This ensures that it is sent in this way. Afterwards, the hose (4) is located on the blind flange (6). The gasket assembly (5) is passed through. The gasket assembly (5) is tightly fitted to the surface of the hose (4). by making contact, it completely closes the gap between the hose (4) and the blind flange (6) and It prevents ammonia gas from leaking into the atmosphere from the tank during operation. In order to ensure the aforementioned seal, the inner diameter of the gasket assembly (5) must be equal to the outer diameter of the hose (4). It is 3 mm narrower than the diameter. The hose, approximately 9150 mm long (4), contains liquid ammonia. It is lowered to the bottom of the tank (1) and mounted on the outside end of the hose (4) The flow of liquid is controlled manually with the ball valve (9). The tank's pump suction pipe, after entering, bends at an angle of approximately 120° to initiate suction. Turning its direction towards the bottom of the tank. The hose (4) fits into this 12-inch blind flange (6) 10 Because it is passed through, it is naturally directed in the same direction and is secure all the way to the bottom. It descends in a certain way. Thus, the movement of the hose inside the tank, the pump suction pipe It is kept under control through his / her guidance. The line coming from the ball valve (9) goes into the separator (11) via the separator inlet line (10). It is directed. At this stage, the gas phase in the fluid coming from the hose (4) is 15 It separates the liquid part and transfers it to the pump (13). The liquid and gas are separated in the separator (11). The distinction can be made thanks to the difference in density. The liquid has a higher density than the gas. The lower phase exits through the separator vent at the bottom, while the less dense gaseous phase exits through the vent at the top. The bottom outlet of the separator (11) is connected to the pump suction line (12) to provide liquid to the pump (13). While this is provided, the upper outlet is connected to the chimney (16) via the chimney outlet line (15) and the gas phase 20 It is safely discharged into the atmosphere. In this context, the water exiting from the separator vent... The gas is directed into an ammonia flare flue. A pilot flame burns continuously in the flare flue. Thanks to this, the harmful ammonia gas that arrives here comes into contact with oxygen and undergoes complete combustion. It undergoes a process and is transformed into a harmless product. The pump (13) takes the liquid from the separator (11). It transfers ammonia through the pump discharge line (14) to the target tank or system. 25 During the operation, the ammonia tank (1) pressure is adjusted to approximately 130 mbar. The flow in the hose (4) is started. Liquid ammonia in the ammonia tank (1) It naturally continues to gasify, and this gasification creates pressure in the tank. Ammonia The pressure control valve on the tank (1) shall be set to a value of 130 mbar. It is being adjusted; the valve closes when the pressure drops below 130 mbar, and closes when it rises above 30 mbar. It opens and directs the excess gas to the flare chimney. A pilot flame burns continuously in the flare chimney. Thanks to this process, the ammonia gas that arrives here is burned and converted into a harmless form. This Under pressure conditions, the pump (13) is activated and the liquid ammonia coming from the separator (11) 7 The pump discharge line (14) transfers the water to the target tank or system. Siphon Thanks to the effect of the hose (4) going down to the bottom, pump that cannot be obtained by classical methods Approximately 1600 tons of liquid ammonia below the suction point are also safely extracted. It can be removed from the tank. Thanks to this method, what would normally take months can be done. The gasification-based discharge process is completed within 3-4 days. This ensures both 5 The operation time is significantly shortened, and the tank can be completely emptied safely. This is carried out in this manner. The evacuation system described in this invention is designed specifically for a particular tank of liquid ammonia. This solution is not applicable to other liquid storage tanks that do not have a drain line. It has the following characteristics. The main feature of the system is that the liquid remaining below the pump suction nozzle level is 10 It is possible to remove it directly to the bottom of the tank via the hose (4). This structure thanks to, those whose design does not include a bottom drain line or whose existing drain line In all tanks that are faulty / immobile, the liquids remaining below the pump suction point It is possible to unload it safely. Blind flange (6) and pulley (7) structure By adapting to different tank types, the hose is sent into the tank in a controlled manner and 15 Sealing with a gasket group (5) is a universally applicable solution. Thus, the invention is applicable not only to ammonia tanks but also to tanks with similar characteristics. The same technical effect is achieved in cryogenic or pressurized liquid storage tanks. is able to place it. 25

Claims

8 REQUESTS 1. In an ammonia tank (1) without a drainage line, the liquid remaining below the pump suction point. It is a discharge system for removing ammonia, and its feature is;  on the tank outlet valve (3) located at the end of the tank outlet pipe (2) positioned blind flange (6), 5  located in the center of the blind flange (6) and the hose (4) to the ammonia tank (1) a pulley (7) that enables its orientation,  During the passage of the hose (4) through the blind flange (6) to the ammonia tank (1), between the outer surface of the hose (4) and the inner surface of the reel (7) and the blind flange (6) a gasket assembly (5) that seals by closing the gap, 10  The end of the hose (4) that is extended into the ammonium tank (1) is located outside the tank a ball valve (9) connected to the part and enabling the flow to be started and stopped It includes.

2. The discharge system mentioned in Claim 1 is characterized by being connected to the separator inlet line (10). and a 15 that enables the separation of the liquid phase fluid from the gas phase coming from the hose (9). It contains a separator (11).

3. The discharge system mentioned in Claim 1 is characterized by the flow from the ball valve (9). a separator connected to the line and to which the liquid ammonia coming from the hose (4) is directed It includes the input line (10).

4. The drainage system mentioned in Claim 1 is characterized by having 20 at the bottom of the separator (11). It includes a pump suction line (12) which is positioned and connected to the pump (13).

5. The discharge system mentioned in Claim 1 is characterized by being located at the top of the separator (11). It includes a gas exhaust line (15) located and connected to the chimney (16).

6. The discharge system mentioned in Claim 1 is characterized by being connected to the pump (13) and A pump discharge line (14) through which liquid ammonia from the separator (11) is transferred 25 It includes.

7. The discharge system mentioned in Claim 1 is characterized by its sealing properties. In order to ensure this, the inner diameter of the gasket assembly (5) must be 3 mm more than the outer diameter of the hose (4). It is narrow.

8. The discharge system mentioned in Claim 1 is characterized by the fact that the diameter of the aforementioned blind flange (6) is 30 It is 12 inches.

9. The discharge system mentioned in Claim 1 is characterized by the aforementioned ball valve (9) Its diameter is 3 inches.