JPS6051529A - Regeneration of adsorbent for drying inert gas - Google Patents

Abstract

PURPOSE:To regenerate an adsorbent under energy saving without taking out a packing layer, by moistening an adsorbent packing layer of which the capacity is lowered while bringing the moistened layer into contact with water to remove a solid salt component. CONSTITUTION:In performing the dehydration of inert gas for shielding the tank provided in a tanker, when the pressure loss of an adsorbent packing layer 2 exceeds predetermined pressure, the supply of oil 13 is stopped and wet air is passed through the absorbent 2 from a blower 14 through pipes 19, 6 to sufficiently moisten the adsorbent 2. Subsequently, a valve 26 is opened to introduce washing water from a pipe 4 and water is sprinkled over the adsorbent 2 from spray nozzles 5. The solid salt component adhered to the adsorbent particle 2 is dissolved and flowed out from a pipe 7. After washing is finished, drainage is performed under gravity and air is sent from an air introducing pipe 30 through a valve 29 to preliminarily dry the adsorbent 2 and, thereafter, air with a temp. of about 150-200 deg.C is sent to dry the same and exhausted from a gas outlet 8. The completion of regeneration is judged by a thermometer 31.

Description

[Detailed Description of the Invention] The technical field of the invention is an inert gas (a gas with almost no flammability or combustibility) for sealing tanks installed on tankers.
This invention relates to a method for regenerating an adsorbent by removing solid salt attached to an adsorbent for adsorbing and removing moisture contained in the adsorbent.

Technical Background As an inert gas used for sealing tanks installed on tankers (oil tankers), combustion gas made by burning fuel such as light oil at approximately the stoichiometric air ratio is brought into direct contact with seawater to cool it. After removing water-soluble components such as sulfur oxides and fine solid particles, drained water was used. However, in cases where it is necessary to maintain the tank interior at a low temperature, such as in LNG tankers, the above treatment alone will cool the residual moisture in the inert gas and assimilate it, causing it to freeze and cause the system to block pipes and valve protectors. Do not use inert gas to avoid damage.
In addition, adsorbents (solid desiccants), e.g.
It was dehydrated using silica etc. However, about 1
When the above-mentioned combustion gas at a temperature of 000°C or higher is rapidly cooled with seawater, the sudden evaporation causes entrainment of droplets, and the water in the droplets evaporates, and sodium chloride (melting point: about 800°C) becomes fine particles and enters the gas. When the floating combustion gas reaches a sufficiently low temperature, a fine mist is generated with this as the core, which flows into the adsorbent packed bed and is either left as is or dehydrated in the gas phase and then attached to the adsorbent or dehydrated. , the pressure loss of the adsorbent packed bed increases,
This caused a decrease in adsorption capacity. In order to reduce the pressure loss in the packed bed due to solid salt, as a method for regenerating the adsorbent,
It goes without saying that in addition to removing water, it is also necessary to remove solid salts (sodium chloride and other trace substances) that are clogging the packed bed. The only methods that have been used include sieving or blowing away with high-speed air, which are not economical because they require complicated work or expensive mechanical equipment.

Purpose of the Invention In view of the above circumstances, the purpose of the present invention is to remove and regenerate solid salts while the adsorbent is placed in the packed bed without taking the adsorbent out of the packed bed or using high-velocity air. An object of the present invention is to provide a method for regenerating an inert gas adsorbent for tanker tanks.

Structure 6 of the invention In J, the sorbent packed bed with solid salt adhesion and increased pressure loss (reduction would reduce processing capacity) is brought into contact with humid gas to sufficiently moisten it. After that, the adsorbent is brought into contact with water to dissolve away the solid salt, and then dried to regenerate the adsorbent. (Wet gas refers to gas with high humidity or gas containing minute water droplets.) In order to perform the desired adsorption in an adsorption operation using a packed bed of adsorbent, at least the amount of gas to be treated in the packed bed must be It is well known that the adsorbent at the most downstream position must maintain adsorption activity (not cause break-through or through-flow). It is also well known that adsorbents used for dehydration (drying), such as alumina glue and silica gel, are porous. However, it is not generally known that these adsorbents break when immersed in water in a dry state. Furthermore, it is hardly known that if these adsorbents are allowed to adsorb water gradually and then immersed in water after reaching a nearly saturated state, no crushing will occur.

In the present invention, the packed bed of the oil-absorbing agent is subjected to humidification treatment by passing one humidity or one gas through it before contacting with water (the entire packed bed is subjected to a humidification treatment of f: q sum - 1' , In a situation where the adsorbent on the outlet side of the humidification process has also reduced its adsorption activity, in other words, the process of humidifying the air at the outlet until it exhibits sufficient humidity is not recommended. This is to allow the R-i agent to gradually adsorb water so that it will not fracture even when immersed in water.A sufficiently moistened adsorbent forms a packed bed.
11. The solid salt is eluted by water flow. Thereafter, it is appropriately filled with water, dried with high-temperature gas, etc., and then reused.

It goes without saying that increasing the amount of adsorbent packed bed can be performed in both the forward and reverse directions, and that both can be used in combination. The adsorbent of the above-mentioned method generally causes grazing and slew, and contains a large amount of water, so it is difficult to fracture, and since the downstream adsorbent is humidified in a relatively slow and sequential manner, it is difficult to fracture.

The flow direction A of the combustion gas to be treated to the filled JeK can be either downward or upward, but if the downward direction is adopted and the humidifying process 3'Jl is also downward, and the water washing is downward. This is desirable because the distance L'L from the downstream part of the packed bed, where a lot of salt adheres, to the outlet is shortened. -! However, it would be more efficient if the washing water was introduced from the bottom of the packed bed and the so-called patch method was used instead of draining it from the bottom.

Furthermore, when comparing the crushing resistance of alumina and silica, alumina generally has higher crushing resistance.

Effects of the Invention By using the method of the present invention, the regeneration of the occlusion is performed on the spot without taking it out from the filling bed, so no extra space is required. This is extremely important in the case of tankers where space is limited.

In addition, since there is no crushing of the adsorbent and there is almost no need for replenishment, there is almost no need to prepare replenishment adsorbent, which saves space and is of course economical.

From these Kokichi, it requires less effort,
The labor cost will be approximately &+).

), the packed bed adsorption device for gas drying +11 contains granular Vfj, adhesive (alumina, trade name Neopeed,
Mizusawa Chemical Co., Ltd.! 8J) +21 is packed on the identified bed, and an inert gas extraction pipe (3), a cleaning water introduction pipe (4) and a spray nozzle (5) are installed at the top 4 &.
At the bottom there is an inert gas introduction pipe (6) and a cleaning water outlet pipe (
7), a gas outlet pipe (8) is provided, and in addition, a level gauge (9), an air vent pulp pipe, etc. are attached.

(It goes without saying that there is no problem even if the inert gas inlet pipe is installed at the top and the same outlet pipe is installed at the bottom.) Oil from the oil pipe θ and air equivalent to the stoichiometric air ratio are introduced from the pipe 1151 by the blower Q41 and combusted, and the combustion gas is passed from the top to the seawater pipe 0 in the cooling tower Oei.
After quenching by direct contact with the seawater introduced in step 71, water droplets are removed in a steam-water separator (119), followed by a gas drying packed bed via the inert gas introduction pipe (6) along the solid line arrow. Water 3j in the gas is successively adsorbed as it rises through the adsorption device f(1).
Dry 1.6 gas is extracted from the top. When the packed bed reaches the 1st brake point # (the point at which moisture in the outlet gas begins to grow), the gas is turned off to another parallel device (not shown). ! The device (1) sends high temperature air heated by a heater (c) in the direction of the chain arrow to desorb adsorbed water and regenerate the adsorbent. However, the adhering salts cannot be removed by the above operations alone, and as the adsorption and regeneration operations are repeated, the salts in the seawater (mainly sodium chloride) become concentrated and precipitate. This precipitated salt is released into the atmosphere from the gas outlet ￥f (8). The end of regeneration is determined by thermometer 1 (1).

[Brief explanation of drawings]

Figure 1 is a flow sheet of 1 implementation N of Kinoe 13J. (1)...A packed bed adsorption device for gas drying is (2)...
Granular adsorbent, (3)...Inert gas Kanada pipe, (4)...
・・Ko water purification pipe, (5) ・・Spray nozzle, (6
)... Inert gas JfJ input V, +71... Cleaning water outlet $Q, tsl... Gas outlet pipe, (9)... Level gauge, 11111... Bleed out pulp, (II!・
... Inert gas made Shinsou 'wLs Rinou... Two! shi6 ・Rashi fba,, ila... Eyagura lt
l, (141... send join Vharuka, H... cooling=”
g, ('η...sea water pipe, haze...steam water separator, 1
24)...Thermometer, 4, 1214...Pressure a1, ~
．．゛n...salt concentration 81, hate...heater, C (goods)
...Air core inlet tube, i' (+1...714 degree meter.

Claims (1)

[Claims] 1. Inert gas used for sealing the tank of a tanker, which is made by cooling the combustion gas produced by combustion at a nearly stoichiometric air ratio with seawater, is dehydrated by passing it through a packed bed of adsorbent. In the inert gas drying method, which heats and dehydrates the moistened adsorbent and reuses it: After moistening the entire packed bed by passing a moist gas through it, the packed bed is brought into contact with water and drained. A method for regenerating an adsorbent for drying an inert gas, which comprises drying and removing solid salts interposed between particles of the absorbent. 2. Filling with adsorbent 1. The method according to item 1, wherein the bow is additionally contacted with a moisture-containing gas before coming into contact with water. 3. The method according to claim 2, wherein the moisture-containing gas is humidified air. 4. The method according to claim 2 or 3, wherein the moisture-containing gas includes atomized water droplets. 5. Defining each point A of the operation by detecting the humidity of the discharged gas or the temperature difference with the inlet gas
4. The method according to any one of 4.