Note: Descriptions are shown in the official language in which they were submitted.
21~71~ ;~
The present invention relates to a method of cleaning oil
contaminated filter medium extracted from oil filters. -
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BACKGROU~lD OF TH:E INVENTION
It is recognized that metal canister oil filters commonly
used in automobiles represent an environmental hazard when
disposed of in land fill sites. Efforts are presently being
made to integrate the disposal of these oil filters into
existing recycling programs. Thes~e efforts involve separating -~
the filter medium from the metal canister. The metal
canisters are then recycled as scrap metal, leaving the filter
medium to be disposed of separately. The filter medium most
15 commonly found in these oil filters is a wet strength grade of
absorbent paper with a plasticized coating on one side. To
this point there has been no effective manner of cleaning the
filter medium to a sufficient degree to permit the used filter
medium to be adapted for a secondary use. In fact, the filter
medium has not been cleaned to a sufficient degree to permit
safe disposal in landfill sites. The oil contaminated filter
medium is presently incinerated. -
25 SUMM~RY OF TEIE INVENTION -
I What is required is a method of cleaning oil contaminated
filter medium extracted from oil filters to a sufficient
degree to allow for safe landfill disposal or recycling for a ~ `
secondary use.
According to the present invention there is provided a
method of cleaning oil contaminated filter medium extracted
from oil filters which includes the following described steps.
Firstly, treat the oil contaminated filter medium with a
biodegradable emulsifying agent, thereby emulsifying oil in
the filter medium. Secondly, soak the oil contaminated filter
medium in a bat;h of biodegradable solvent compatible with the
biodegradable emulsifying agent, thereby dissolving remaining
oil in the filter medium.
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211~7~6
Although beneficial results may be obtained through the
use of the method, as descrlbed, it is preferred that measures
be incorporated in the method to recycle as much of the
solvent and emulsifying agent as possible. This makes
economic sense as it reduces the cost of the methodO Thi~
also enhances the beneficial results obtained as it reduces
the residue of solvent and emulsifying agent in -the filter
medium. Even more beneficial :results may, therefore, be
obtained by introducing intermediate steps of wringing excess
solvent and emulsifying agent from the filter medium. There
are a number of different presses and other mechanical means
by which this may be done.
Although beneficial results may be obtained through the
15 use of the method, as described, it is preferred that measures -~
be taken to enhance the effectiveness of the emulsifying
agent. The agitation of the filter medium has been found to be
beneficial. Even more beneficial results may, therefore, be
obtained by agitating the fil-ter medium during the emulsifying
step.
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BRIEF DESCRIPTION OF THE DRAWINGS --~
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These and other features of the invention will become
more apparent from the following description in which
re~erence is made to the appended drawings, wherein~
FIGURE 1 is a flow diagram of a method according to the
teachings of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred method of cleaning oil contaminated filter
medium 10 extracted from oil filters will now be described
with reference to FIGVR~ 1 7 , '
Referring to FIGURE 1, the preferred method includes the
following steps;. Firstly, treat the oil contaminated filter
7 1 ~
` medium 10 with a biodegradable emulsifying agent by placing
filter medium 10 in a bath of biodegradable emulsifying agent
12, and agitating with mechanical agitator 14. This serves to
emulsifying oil in filter medium 10. Secondly, wring excess
~¦ 5 emulsifying agent out of filter medium through the use of a
first set of mechanical wringers 16. Thirdly, soak the oil
~ contaminated filter medium 10 ;n a bath of biodegradable
i solvent compatible 18 with the biodegradable emulsifying
agent. This dissolves remaininq oil in the filter medium.
10 Fourthly, wring excess solvent out of filter medium 10 through
the use of a second set of mechanical wringers 20. After the
described steps are performed the oil contc~mination level in
~, filter medium 10 is reduced to less than one percent (1%). It¦~ is important that the solvent and emulsifying agent both be
15 biodegradable, otherwise the process will be counter-
productive as the solvent and emulsifying agent will
contaminate filter medium 10. There is no point in
substituting one form of contamination for the oil
contamination. It is also important that the emulsifying
20 agent selected be compatible with the solvent being used to
Z ensure best results. Beneficial results have been obtained
through the use of an orange based food grade solvent. The use
of biogradable solvents and emulsifying agents render filter
medium 10 suitable for disposal in land fill sites. However,
25 filter medium 10 is suitable for use in a variety of secondary
~ uses after processing according to this method, and such a
$ valuable product should not have to be disposed of in land
fill sites. Filter medium 10 has tremendous oil absorbing
capabilities, which i8 why it was selected for use in the oil
30 filters in the first place. After processing in accordance
with the described method, filter medium 10 has a residue of
j solvent which makes it repel water. Filter medium 10 can be
~ used in mechanic shops as oil absorbent mats. The oil
¦ absorbent mats can be cleaned by following the described
~ 35 method. The fact that filter medium 10 repels water after
¦ processing in accordance with the described method enables it
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210~71 6
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to be used in the clean up of oil spills on bodies of water,
such as our lakes and rivers.
It will be apparent to one skilled in the art that
modifications may be made to the described method without
departing from the spirit and scope of thP invention as
defined by the Claims.
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