Ethylene spherical tank cooling depressurizing method

Abstract

The invention discloses an ethylene spherical tank cooling depressurizing method in the petrochemical engineering field. The ethylene spherical tank cooling depressurizing method comprises the steps that (1) an ethylene transfer pump is started when a pressure transmitter detects that the ethylene gas-phase pressure at the top of an ethylene spherical tank is superhigh and an alarm is given out, and overheated liquid-phase ethylene is conveyed to a circulating refrigeration unit; (2) the overheated liquid-phase ethylene is transferred into low-temperature liquid-phase ethylene after being cooled through the circulating refrigeration unit, and the low-temperature liquid-phase ethylene is transferred into low-temperature liquid-phase mist and sprayed out after passing through a spraying annular screen pipe; (3) the sprayed low-temperature liquid-phase ethylene is mixed with the overheated liquid-phase ethylene at the top of the ethylene spherical tank, and the storage pressure and temperature of the gas-phase ethylene above the liquid-phase ethylene of the ethylene spherical tank are lowered; (4) when the pressure transmitter detects that the pressure of the ethylene spherical tank is lowered to be a safe value, the ethylene transfer pump is stopped; and (5) when the pressure transmitter detects that the ethylene gas-phase pressure at the top of the ethylene spherical tank is superhigh and the alarm is given out again, the steps from (1) to (4) are repeated. According to the technique of the ethylene spherical tank cooling depressurizing method, rapid cooling depressurizing and cooling of the ethylene spherical tank can be achieved, and processing equipment is concise and small in investment.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and in particular relates to a process method for rapid cooling and depressurization of an ethylene spherical tank. Background technique [0002] Ethylene is one of the largest chemical products in the world. The ethylene industry is the core of the petrochemical industry. Ethylene products account for more than 75% of petrochemical products and occupy an important position in the national economy. With the continuous development of the domestic ethylene industry, the problem of ethylene storage will become increasingly prominent. At present, there are two domestic ethylene storage methods: 1. Low-temperature pressure storage, that is, spherical tank pressure storage, which is widely used at present; 2. Ultra-low temperature and atmospheric pressure storage, using ultra-low temperature vertical storage tanks, which have high operating costs and are rarely used. [0003] The operating condit...

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Problems solved by technology

[0008] The invention proposes a method for cooling and depressurizing an ethylene spherical tank to solve the problems of low cooling efficiency and slow depressurization speed of the liquid-phase ethylene cooling method and large investment and high energy consumption of the gas-phase ethylene cooling method in the prior art

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