JPS648561B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is made of fibers having a specific water swelling property and is composed of fiber aggregates of a specific density, and is capable of dispersing water finely dispersed in oil into coarse particles. The present invention relates to a filter that can be separated and removed.

In recent years, efforts have been made to extend the lifespan of oil by removing water mixed in water-immiscible organic liquids (oils) such as insulating oils, lubricating oils, and organic solvents, especially water that forms stable emulsions. There is a strong demand for the realization of technical means that enable recovery and reuse, and granular materials of inorganic salts such as silica gel and zeolite are used in some cases for this purpose. However, although it is possible to remove some water with such inorganic salts, their water removal ability is extremely low, and furthermore, such inorganic salts have the inherent defect that they are mixed into purified liquids to some extent, and therefore cannot be used. Its field of use had to be restricted. In addition, some attempts have been made to use fibers such as natural pulp that have some degree of hygroscopicity or water absorption, but these have extremely low water removal ability and are of little practical use.

Therefore, the present inventors focused on the instantaneous large water absorption capacity or water retention capacity of water-swellable polymers (hydrogel), and investigated the possibility of using such hydrogels as water removal materials for liquids. However, when using granular hydrogel, because it has excellent water absorption performance, it swells instantaneously and causes clogging, which makes it necessary to stop water removal treatment in an extremely short period of time. found. Therefore,
In order to improve such clogging, we tried using a hydrogel in the form of fibers, and although it was possible to extend the water removal treatment time to some extent compared to granular hydrogels, it still caused clogging due to swelling and settling of the fibers. This problem could not be overcome, and the water absorption performance could not be demonstrated. Therefore, as proposed in JP-A No. 55-106539, the present inventors proposed a single water-swellable fiber having a multiphase structure of a hydrogel outer layer and an AN yarn polymer and/or other polymer inner layer. It has been found that by using a single product or a mixed product of this fiber and other fibers, water removal treatment can be performed for a long time without the fibers becoming sag, and the water absorbing performance of the hydrogel can be fully demonstrated.

The water removal material described in this earlier application made it possible to operate the water removal treatment for a long time without clogging or sagging the fibers, but as is clear from its mechanism of action, water removal is not possible. It is not possible to perform a water removal operation that exceeds the water-swelling performance (water absorption capacity) of the water-swellable fibers constituting the filter, and therefore, such a filter can be suitably used especially in the regeneration treatment of oil containing a trace amount of water. It was a means.

Under these circumstances, the inventor of the present invention conducted intensive research to provide a water removal filter that can be used semi-permanently, and surprisingly found that it is made of fibers with specific water swelling characteristics and has a specific density. We discovered the fact that by passing the oil to be treated through a filter made of fiber aggregates, water that is stably finely dispersed in the oil to be treated can be effectively coarsened and separated and removed semi-permanently. , arrived at the present invention.

That is, the main object of the present invention is to provide a water-removal filter for water-containing oil that has excellent water-removal ability and can be used semi-permanently for oils (organic liquids) containing a wide range of dispersed amounts of water. Our goal is to provide the following.

Another object of the present invention is that since it is a molded product of fiber aggregates, the density (fiber gap) of the fiber aggregates can be adjusted appropriately, and it is possible to adjust the viscosity, water content, supply rate, etc. of the oil to be treated over a wide range of conditions. The purpose of the present invention is to provide a water-removal filter for water-containing oil that can be applied in various embodiments, and other objects of the present invention will become clear from the detailed description of the present invention described below.

A water removal filter for hydrous oil that can achieve the above-mentioned object of the present invention is made of water-swellable fibers having a water swelling degree of 2 to 20 c.c./g alone or a mixture of the fibers and other fibers, It is composed of a fiber aggregate having a density of 0.002 to 0.05 g/cm ³ .

Here, the fiber aggregate constituting the filter according to the present invention is composed of fibers having a water swelling degree of 2 to 20 c.c./g alone or a mixture of the fibers and other fibers, and If the water swelling degree of the swellable fiber is outside the recommended range of the present invention, the water removal performance aimed at by the present invention cannot be exhibited. Note that such water-swellable fibers can be employed as long as they have a predetermined degree of water swelling. If water-swellable fibers that are composed of an inner layer such as a coalescence and have crimps are used, fiber fatigue,
This is desirable because it does not cause problems such as clogging. In addition, other fibers that may be mixed as desired include cotton,
Examples include natural fibers such as wool; recycled or semi-synthetic fibers such as rayon, Kyupra, and acetate; synthetic fibers such as polyolefin, polyamide, polyester, and acrylic; and the mixing ratio of such other fibers is as follows: It is used in a proportion of approximately 95% by weight or less.

Next, the density of the above fiber aggregate is 0.002~
It is necessary to set it within a range of 0.05 g/cm ³ , and if the upper limit of this range is exceeded, water droplets cannot be generated.

The fiber aggregate according to the present invention can be in any known form such as short fibers, webs, nonwoven fabrics, paper sheets, knitted fabrics, and spun yarns, but nonwoven fabrics and yarns made of the fiber aggregates can be used. A filter formed into a cylindrical shape by being wound around a middle tube with a plurality of holes is desirable. In particular, a nonwoven fabric made of water-swellable fibers and heat-adhesive polyolefin composite fibers is preferable. It is desirable because even in a low-density state as in the present invention, fiber gaps can be maintained and the water coarsening and separation effects can be fully exhibited without causing problems such as settling and clogging.

The oil to be treated to which the above-mentioned water removal filter according to the present invention is applied is a liquid under water removal treatment conditions and undergoes phase separation from water (even if some mutual dissolution occurs, phase separation does not occur). It is a general term for things. Those having such properties include petroleum ether, pentane, hexane, heptane,
Petroleum hydrocarbons such as petroleum benzine; alicyclic saturated hydrocarbons such as cyclohexane and cyclooctane; aliphatic unsaturated hydrocarbons such as 1-octene and cyclohexene; aromatic compounds such as benzene, toluene, xylene and styrene. Hydrocarbons; halogenated aliphatic hydrocarbons such as tetrachlorethylene, methylene chloride, chloroform, carbon tetrachloride; spindle oil, refrigeration oil, dynamo oil, turbine oil, machine oil, cylinder oil, marine engine oil, gear oil , cutting oil, hydraulic oil, compressor oil, and other lubricating oils.

The water removal filter according to the present invention as described above is 50
It can be used as a water removal material for oil (to-be-treated oil) that contains less than 10% water, and by passing the oil to be treated through such a filter, the water finely dispersed in the oil to be treated is combined. The average diameter is 2 mm or more,
More preferably, it is possible to coarsen particles to 3 mm or more and separate and remove them, and with the advent of such a filter, it is possible to industrially regenerate organic liquids (oil) that were conventionally discarded or required a great deal of cost to recover. The significance of paving the way for reuse is significant.

The filter of the present invention is even more effective in an embodiment in which the water in the oil to be treated is pre-treated to coarsen the finely dispersed water in the oil using an appropriate filter, and the water in the oil to be treated is further coarsened and separated by sedimentation. can be done.

In order to further facilitate understanding of the present invention, Examples are described below, but the gist of the present invention is not limited in any way by the description of these Examples.
It should be noted that all percentages and parts described in the Examples are based on weight unless otherwise specified.

The water content (%) and water swelling degree in the treated oil described in the Examples were measured or calculated using the following method.

(1) Water content (%) in treated oil The treated oil was placed in a 500 ml beaker, left to stand for 1 minute, and then 1 g of oil was sampled from a 2 cm distance from the top and measured using the Karl Fischer method.

(2) Water swelling degree (cc/g) Immerse the sample in pure water, keep it at 25℃ for 24 hours, wrap it in nylon cloth (200 mesh), and use a centrifugal dehydrator (3G x 30 minutes, where G is gravity). acceleration)
water between the fibers is removed. Measure the weight of the sample prepared in this way (W ₁ g).

Next, the sample is dried in a vacuum dryer at 80° C. until the temperature is constant, and the weight is measured (W ₂ g).

From the above measurement results, it was calculated using the following formula. Therefore, the actual water swelling degree is a numerical value indicating how many times the weight of the fiber can absorb and retain water.

(Water swelling degree) = W ₁ - W ₂ / W ₂ Example Two-component bonded acrylic composite fiber (manufactured by Nippon Exlan Kogyo, single fiber fineness: 2d, Varicut)
70% and two-component bonded polyolefin composite fiber (low density polyethylene: crystalline polypropylene = 1:1, single fiber fineness: 3d, fiber length: 51mm)
Make a web by carding 30% and heat to 145℃.
A nonwoven fabric was prepared by dry heat treatment for 10 minutes. A 30% aqueous solution of caustic soda was evenly spread on the obtained nonwoven fabric so that 30% of the fabric adhered to the nonwoven fabric, and then placed in an autoclave and heated with saturated steam at 105°C for 4 minutes.
The residual alkali was removed by washing with water and dried to produce a white to slightly yellow water-swellable nonwoven fabric with a basis weight of 16 g/m ² and a density of 0.01 g/cm ³ . Note that the outer layer of the acrylic fibers constituting the nonwoven fabric is hydrogelated, and
It had a water swelling degree of cc/g.

A filter was prepared by wrapping the nonwoven fabric in a single layer around a middle cylinder having a diameter of 30 mm and a length of 247 mm (having 720 small holes of 3 mm in diameter).

With the water remover equipped with the obtained filter, 2%
When treating turbine oil containing water (however, most of the water exists in the form of 2 to 4 mm droplets),
Water droplets of 3 to 6 mm in size were formed in the oil, and the water droplets quickly settled to allow continuous separation and removal of water. The water content in the treated oil was 0.009%.

Claims (1)

[Claims] 1. Consisting of water-swellable fibers having a degree of water swelling of 2 to 20 c.c./g, or a mixture of these fibers and other fibers, and having a density of 0.002 to 0.05 g/cm ³ A water removal filter for water-containing oil made of fiber aggregate. 2. A water-removal filter for hydrous oil according to claim 1, which is formed into a cylindrical shape by winding a nonwoven fabric or thread made of a fiber aggregate around a middle cylinder having a plurality of holes.