Device for cyclic dewfall air-return adjustment of large low-temperature liquid cargo ship

Abstract

The invention discloses a device for cyclic dewfall air-return adjustment of a large low-temperature liquid cargo ship. The device comprises a cargo cabin air return header pipe and a dry isolation cabin air return header pipe which are connected to an emptying hole of a cargo cabin / dry isolation cabin, wherein the cargo cabin air return header pipe and the dry isolation cabin air return header pipe are connected to a balance valve; one outlet of the balance value is successively connected to a venturi tube, an air filter and a pressure balance tank; two air outlets of the pressure balance tank are connected to an escape pipe and an inlet end of an original drying dewfall device of the ship; a water outlet of the air filter is connected to a condensed water drainage pipeline; an air supplementation hole of the venturi tube is connected to a new air pipe; and another outlet of the balance value is connected to the escape pipe. According to the invention, the cabin-charging discharge gas which has a certain pressure and is treated by drying and dewfall is used repeatedly; equipment such as the venturi tube is used to generate effects of temperature decrease, pressure decrease and negative-pressure absorption; and the gas is mixed with the supplemented air, and pressure adjustment is conducted then, so that a gas dew point at the inlet of the original drying dewfall device of the ship can be reduce cyclically and continuously.

Description

technical field [0001] The invention relates to a drying and dew-reducing technology during the loading process of a low-temperature liquid cargo ship, in particular to a large-scale low-temperature liquid cargo ship circulation dew-returning air adjustment device. Background technique [0002] For LNG, it is very important for LEG cryogenic cargo ships to reduce and maintain the low dew point value of liquid cargo tanks and dry compartments (such as C-type independent cargo tank ships). It will also condense into micro-ice and affect the operation of the submersible liquid cargo pump, causing damage to the pump shaft and other components; for dry compartments, if the dew point is too high, it will affect the insulation effect of the insulation layer, and seriously cause the insulation to fail. Therefore, according to the process and product instructions It is required to dehumidify and dew the cargo hold and dry compartment before loading. The dew point generally needs to r...

AI Technical Summary

Problems solved by technology

[0004] Under the one-way open dew drop and tank filling mode of the ship, the tank filling gas with a certain pressure after the dew treatment is directly emptied, which causes waste. The processing capacity of the dew reduction equipment is limited. If the processing capacity of the dryer is exceeded, the load of the dryer will increase, and the dew reduction effect will become worse. The dew point requirement value has strict standards, and ships often seriously affect the ship's operating time and loading efficiency due to the long operation time of the ship's dew point process

In addition, the ship's gas drying system mostly adopts the form of adsorption drying (or combination mode of suction and drying). If it is used in overload for a long time, the energy consumption of the drying equipment will increase, and the consumption of adsorption filters and other consumables will increase, which will shorten the service life of the overall equipment.

Images