BOIL OFF GAS RELIQUEFACTION APPARATUS USING PACKING TOWER

摘要

A BOG(Boil-Off Gas) reliquefaction apparatus using a packing tower is provided to quickly cool down BOG by vaporizing LNG(Liquefied Natural Gas) together with the BOG by applying the LNG on the surfaces of packing bodies filled into the packing tower. The BOG reliquefaction apparatus using a packing tower(18) is composed of a BOG compression unit(1) compressing BOG vaporized from the inside of an LNG storage tank(10); an actuating fluid compression unit(4) having plural actuating fluid compressors(41,42,43) and actuating fluid coolers(44,45,46) connected to repeat compressing and cooling steps to pressurize and supply the actuating fluid in a very low temperature refrigerating cycle liquefying the BOG; and a cold box unit(2) liquefying the BOG by expanding the actuating fluid contained in the actuating fluid compression unit at very low temperature and then exchanging heat of the actuating fluid with the BOG in a condenser(20). The BOG reliquefaction apparatus recirculates the BOG liquefied by the cold box unit to the storage tank. The packing tower is installed between the BOG compression unit and the storage tank. The BOG evaporated from the storage tank is mixed with the LNG supplied from the outside in the packing tower. The packing tower contains plural packing bodies having surfaces to be coated with the LNG. The BOG is cooled by the evaporative latent heat of the LNG applied on the packing bodies.