Non-condensable gas recovery device during filling of liquid ammonia tank truck
By designing a non-condensing gas recovery device including a scrubber, the problem of improper non-condensing gas treatment during the filling process of the liquid ammonia tanker is solved, and the effective separation and combustion of ammonia in the non-condensing gas is achieved, which reduces system load and environmental pollution, and reduces costs.
Patent Information
- Application Number
- CN202420852184.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-23
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-04-23
AI Technical Summary
The non-condensation gas generated by the liquid ammonia tank truck during the filling process is improperly treated, resulting in excessive non-condensation gas content in the gas ammonia, affecting the production system. The ice machine recycling system cannot be effectively separated when there is too much non-condensation gas, resulting in abnormal system operation and environmental pollution.
A non-condensation gas recovery device is designed, including a scrubber, which washes and absorbs ammonia through the spray pipe and filler layer. The remaining non-condensation gas enters the sewage scrubber layer and further removes it, and then enters the torch system to burn to avoid environmental pollution.
The ammonia in the non-condensed gas is effectively separated, the load on the ice machine system is reduced, environmental pollution is reduced, and the cost is reduced by washing with sewage and the pressure on the sewage treatment system is reduced.
Smart Images
Figure CN222694396U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of chemical industry and relates to a non-condensable gas recovery device in the filling of a liquid ammonia tank truck. Background Art
[0002] In the transportation of chemical materials, liquid ammonia often needs to be transported to various production enterprises or refrigeration enterprises, and it is mainly transported by tank trucks. After the tank truck arrives at the destination and is unloaded to the user's storage facility, some non-condensable gases will enter the tank truck. When the tank truck is filled at the filling stack, the gas in the tank truck needs to be recovered to ensure the two-phase balance.
[0003] At present, there are two methods for treating the gas phase of liquid ammonia tank trucks. One is to directly introduce it into the gas ammonia main pipe and use it as raw material for various users. When the tank truck is filled with a small amount, the non-condensable gas in the tank truck has little impact on production, but when the liquid ammonia is filled with too much, it will cause the non-condensable gas content in the gas ammonia to be too high, which will have a greater impact on the production system. Another method is to load the gas phase of the tank truck into the ammonia storage tank, release the ammonia in the gas phase through the vent valve, or recover the ammonia in the gas phase through the ice machine, control the pressure of the ammonia storage tank, and vent the gas to recover the ammonia in the gas phase through the washing. However, if the washing device is not well controlled, the ammonia in the exhaust gas will pollute the environment; if the gas in the ammonia storage tank is recovered by the ice machine, when there is too much non-condensable gas, the ice machine air separation system is not enough to completely separate the non-condensable gas, resulting in abnormal operation of the ice machine system and the ammonia tank pressure cannot be effectively controlled. Summary of the invention
[0004] The utility model provides a non-condensable gas recovery device in the filling of a liquid ammonia tank truck, which can process the discharged gas of the tank truck, wash and recover ammonia in the non-condensable gas, and the remaining non-condensable gas can be discharged into a flare system for combustion, thereby avoiding impact on the environment.
[0005] The technical solution of the utility model is a non-condensable gas recovery device during the filling of a liquid ammonia tank truck, comprising a washing tower, the bottom of the washing tower is a washing liquid tank, the lower section of the washing tower is provided with an air inlet, the air inlet is connected to a non-condensable gas conveying pipe, the middle and upper sections in the washing tower are provided with at least two levels of packing layers, a spray pipe is provided above each level of the packing layer, and a gas phase outlet is provided at the top of the washing tower; the washing liquid tank is provided with a discharge port, which is connected to the liquid inlet of the spray pipe through a pipeline and a circulating pump, and the spray pipe is also connected to a desalted water replenishment pipe; a sewage washing layer is also provided in the washing tower between the spray pipe and the gas phase outlet, a sewage inlet is provided on the upper side of the sewage washing layer, and a sewage outlet is provided on the lower side.
[0006] Furthermore, the washing tower is a special-shaped tower, including an upper tower and a lower tower, and the diameter of the lower tower is larger than the diameter of the upper tower.
[0007] Furthermore, a cooler is provided on the pipeline between the circulation pump and the liquid inlet of the spray pipe.
[0008] Furthermore, a concentration detector and an ammonia extraction pipe are provided on the pipeline between the circulation pump and the liquid inlet of the spray pipe, and an extraction valve is installed on the ammonia extraction pipe.
[0009] Furthermore, a bubble cap tray is provided between adjacent packing layers and the spray pipe.
[0010] Furthermore, the desalted water replenishment pipe is connected to the liquid inlet of the spray pipe on the uppermost layer in the washing tower.
[0011] The utility model has the following beneficial effects:
[0012] The utility model sets a washing tower to replace the ice machine system to process the non-condensable gas in the tank car during the liquid ammonia filling, separates the ammonia and inert gas in the non-condensable gas, and avoids the load of the ice machine system when the filling volume is large. It uses desalted water to wash and absorb the ammonia in the non-condensable gas to prepare 15-20% ammonia water, which can be used as a raw material for boiler desulfurization and denitrification. The remaining gas phase enters the sewage washing layer, and a large amount of sewage is used to further wash and remove the ammonia in the gas phase. Compared with washing with desalted water, it can greatly reduce the cost, and the sewage discharged after the sewage washing directly enters the terminal sewage treatment system, which will not cause great pressure on the removal of ammonia nitrogen in the sewage. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a structural schematic diagram of the device of the utility model. DETAILED DESCRIPTION
[0014] The embodiments of the present invention will be described in detail below in conjunction with examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.
[0015] like Figure 1 As shown, the utility model provides a non-condensable gas recovery device during the filling of a liquid ammonia tank truck, comprising a washing tower 1, the bottom of the washing tower is a washing liquid tank 2, the lower section of the washing tower is provided with an air inlet 3, the air inlet is connected to a non-condensable gas conveying pipe 4, the middle and upper sections in the washing tower are provided with at least two levels of packing layers 5, a spray pipe 6 is provided above each level of the packing layer, and a gas phase outlet 7 is provided on the top of the washing tower; the washing liquid tank is provided with a discharge port 8, which is connected to a spray pipe inlet 10 through a pipeline and a circulating pump 9, and the spray pipe is also connected to a desalted water replenishment pipe 11; a sewage washing layer 12 is also provided in the washing tower between the spray pipe and the gas phase outlet, a sewage inlet 13 is provided on the upper side of the sewage washing layer, and a sewage outlet 14 is provided on the lower side.
[0016] The device sets a sewage washing layer at the top of the washing tower. At this time, the residual ammonia in the non-condensable gas is further removed by washing with a large amount of sewage, and then enters the flare system for combustion to avoid environmental impact. Compared with washing with a small amount of desalted water, washing with a large amount of sewage has low cost and good washing effect.
[0017] Preferably, the washing tower is a special-shaped tower, including an upper tower and a lower tower, and the diameter of the lower tower is larger than that of the upper tower. In the process of the non-condensable gas entering the lower end of the washing tower and rising, there is a part where the diameter of the tower is reduced, and the non-condensable gas here can be further concentrated to carry out washing mass transfer with the downward circulating ammonia water or desalted water, and fully absorb the ammonia in the non-condensable gas.
[0018] In another preferred case, a cooler 15 is provided on the pipeline between the circulation pump and the liquid inlet of the spray pipe, and the temperature in the circulation pipeline is controlled below 40°C by passing a cooling medium for heat exchange, thereby ensuring the absorption efficiency of the circulating ammonia water. The heat exchange tube in the cooler that contacts the ammonia water is made of 304 stainless steel to prevent the pipeline from corroding and perforating, and the ammonia water leaking into the circulating water system, which affects the water quality of the circulating water.
[0019] In another preferred case, a concentration detector and an ammonia extraction pipe are also provided on the pipeline between the circulating pump and the liquid inlet of the spray pipe, and an extraction valve is installed on the ammonia extraction pipe. A control valve can also be provided on the desalted water replenishment pipe, and the concentration detector is electrically connected to the ammonia extraction valve and the desalted water replenishment pipe through a controller, respectively, to realize automatic control of ammonia concentration. Specifically, the signal output end of the concentration detector is connected to the signal input port of the controller, and the signal output end of the controller is respectively connected to the ammonia extraction valve and the desalted water replenishment pipe control valve. The specific controller controls the ammonia extraction and desalted water replenishment through the input signal of the concentration meter, which belongs to the conventional technical means of those skilled in the art and will not be repeated in this specification.
[0020] In a specific preferred case, a bubble tray 16 is provided between adjacent packing layers and the spray pipe, and its arrangement can slow down the flow rate of the gas in the washing tower, so as to achieve more sufficient washing and mass transfer.
[0021] In a specific preferred case, the desalted water replenishment pipe is connected to the liquid inlet of the spray pipe on the uppermost layer in the washing tower, and the replenished desalted water is directly used to wash the non-condensable gas on the upper layer, which can fully remove the ammonia therein.
[0022] In the specific operation, the gas phase in the tank truck when the liquid ammonia crane is filled is introduced into the non-condensable gas conveying pipe and enters the lower section 1 of the washing tower. Under the pressure of 0.7MPa, it first passes through the packing layer in the washing tower, and is washed with circulating ammonia water or desalted water (the ammonia water in the washing liquid tank is pumped into the upper section of the washing tower through the pipeline under the action of the circulating pump and sprayed into the packing layer through the spray pipe. It is absorbed again by the desalted water or circulating ammonia water in the packing layer. After multiple packing layer and spray pipe washing, the remaining gas enters the sewage system formation for further washing, and finally enters the flare system through the gas phase outlet at the top of the washing tower for combustion.
[0023] In a specific case, the washing tower is about 13.8 meters high and adopts a special-shaped tower. The diameter of the upper tower is 0.5 meters and the diameter of the lower tower is 3.2 meters. The lower tower is used to store circulating ammonia water. The ammonia water in the lower tower is transported to the spray head of the upper tower through a circulating pump. Through continuous circulation and absorption, the concentration of ammonia water is controlled within the range of 15%-20%; the cooler controls the temperature of the circulating ammonia water to below 40°C.
[0024] During operation, the ammonia concentration detector measures the ammonia concentration. When the ammonia concentration is higher than 20%, the controller sends a start command to the desalted water replenishment pipe control valve 16, replenishes water with desalted water to reduce the ammonia content, and controls the opening of the ammonia production valve through the controller to drain the ammonia. When the ammonia concentration is less than 15%, the production valve and the control valve are closed through the controller 8.
[0025] The above embodiments are only for illustrating the technical ideas and features of the utility model, and the contents are only preferred embodiments of the utility model, but the protection scope of the utility model is not limited thereto. Within the technical scope disclosed by the utility model, equivalent changes or improvements based on the technical solution and utility model concept of the utility model should be included in the protection scope of the utility model.
Claims
1. A non-condensable gas recovery device during the filling of a liquid ammonia tanker, characterized in that: The invention comprises a washing tower, the bottom of which is a washing liquid tank, the lower section of which is provided with an air inlet, the air inlet being connected to a non-condensable gas conveying pipe, the middle and upper sections of which are provided with at least two levels of packing layers, a spray pipe being provided above each level of the packing layer, and a gas phase outlet being provided at the top of the washing tower; a discharge port is provided at the washing liquid tank, which is connected to a liquid inlet of the spray pipe through a pipeline and a circulating pump, and the spray pipe is also connected to a desalted water replenishing pipe; a sewage washing layer is also provided in the washing tower between the spray pipe and the gas phase outlet, a sewage inlet is provided on the upper side of the sewage washing layer, and a sewage outlet is provided on the lower side.
2. The device according to claim 1, characterized in that: The washing tower is a special-shaped tower, comprising an upper tower and a lower tower, and the diameter of the lower tower is larger than the diameter of the upper tower.
3. The device according to claim 1, characterized in that: A cooler is also provided on the pipeline between the circulation pump and the liquid inlet of the spray pipe.
4. The device according to claim 1, characterized in that: A concentration detector and an ammonia extraction pipe are also provided on the pipeline between the circulation pump and the liquid inlet of the spray pipe, and an extraction valve is installed on the ammonia extraction pipe.
5. The device according to claim 1, characterized in that: A bubble cap tray is arranged between adjacent packing layers and the spray pipe.
6. The device according to claim 5, characterized in that: The desalted water replenishment pipe is connected to the liquid inlet of the spray pipe on the uppermost layer in the washing tower.