Liquid ethylene atmospheric storage tank
liquid ethylene atmospheric storage tank
Liquid ethylene atmospheric storage tanks are important equipment for liquid ethylene liquefaction plants, storage stations, receiving stations and other stations. It has the characteristics of large storage volume, low working pressure and high safety factor.
There are two main overall structures of liquid ethylene atmospheric storage tanks:
1. Single-container tanks (volume≤6000m3) mostly adopt vertical flat bottom, cylinder, double wall, internal and external self-arching structure.
2. Single-containment tanks (volume>6000m3) and full-containment tanks mostly adopt vertical flat-bottomed, cylindrical, double-walled, inner suspended ceiling, and outer self-arching structures. The outer tank of the full-contained tank has a thermal corner protective layer.
The liquid ethylene atmospheric pressure storage tank is filled with pearl sand to keep cold, and the bottom interlayer is made of foam glass bricks to keep cold. When working, the interlayer is filled with dry nitrogen to ensure that the pearl sand is in a dry state for a long time, so that the storage tank has a lower evaporation rate.
Liquid ethylene atmospheric tank composition: inner tank, outer tank, bottom insulation layer, mezzanine insulation layer, equipment ladder platform, equipment valve instrumentation and basic platform.
The equipment foundation adopts the overhead type. The entire equipment is located on a reinforced concrete foundation platform. The bottom of the foundation platform is supported by concrete columns. The equipment foundation is ventilated and moisture-proof, and the equipment is elevated.
The inner tank is mainly composed of tank top, cylinder and bottom plate. The materials of each part are made of austenitic stainless steel S30408, which is used to store liquid ethylene liquid.
The outer tank is mainly composed of a top cover, a cylinder and a bottom plate, and the material of each part is made of Q345R steel plate.
The inner and outer top cover adopts warp and weft ribbed vault structure, and the cylinder adopts built-in angle steel ring reinforcement structure. The bottom plate adopts a pressure-bearing structure combined with a bow-shaped edge plate and a middle web plate.
Equipment ancillary structure: the storage tank is equipped with a ladder, operation platform, and fire-fighting facilities. The surface paint adopts Jotun's imported paint, which will not fade for 2 years and will not be peeled. The service life of the storage tank is not less than 20 years.
The storage tank can be customized according to the specific requirements of the customer. The general parameters of the conventional storage tank are as follows:
Single tank container: 200-100000m3
The liquid ethylene is sent to the liquid ethylene storage tank through the vacuum pipeline or the cold insulation pipeline, and is divided into 2 paths (top and bottom liquid inlet methods) before entering the liquid ethylene storage tank and enters the storage tank for storage. The liquid inlet and outlet pipelines are all vacuum pipes to reduce cold loss; the liquid inlet pipeline into the storage tank and the top and bottom adopts a ring-shaped spray device to ensure uniform cooling of the inner tank during the first liquid inlet and avoid excessive local temperature stress. .
The liquid ethylene is discharged through the drain port at the bottom of the storage tank, and the drain pipeline is drawn out by vacuum piping to reduce cold loss; a normally open low temperature root valve is set on the drain line, and a remote control emergency shut-off valve is also set. The discharge pipeline is also equipped with a gas seal structure inside the equipment, and is led out from the bottom of the inner tank to ensure that the liquid is drained; in order to facilitate the pre-cooling and start-up of the pump, the discharge port is equipped with an anti-vortex structure to avoid pump cavitation. .
When the pressure at the top of the inner tank reaches 15KPa, the BOG pressure regulating valve opens and the ethylene gas enters the BOG recovery system.
The storage tank is equipped with a self-pressurization system. When the pressure in the storage tank drops to 5KPa, the pressurization control valve opens, and the pressurization system pressurizes the storage tank. When the pressure reaches 10KPa, the pressurization control valve closes.
Air supplement system:
If there is insufficient pressurization of the pressurization system, when the gas phase pressure of the inner tank drops to 2KPa, the corresponding air supplement valve XV10704 opens, and the storage tank increases pressure. When the pressure rises to 10KPa, the air supplement valve closes;
Sandwich nitrogen sealing system:
The dry nitrogen of the system enters the interlayer space of the storage tank through a self-operated regulating valve and a nitrogen flow meter and maintains a positive pressure (less than 0.8KPa) to avoid the entry of moist air and maintain the good thermal insulation performance of pearl sand.
Backflow system after pump, analysis and sampling system, liquid level, pressure measurement system, fire fighting system, etc.
Nanyang Duer Gas Equipment Co., Ltd. is a joint-stock high-tech enterprise. The company is located in the picturesque north of the Han River and south of Funiu; the source of the South-to-North Water Diversion-Nanyang, the land of......
South Section of Jingyi Road, Industrial Cluster District, Sheqi County, Nanyang City, Henan Province