METHODE DE DECONTAMINATION DE COMPOSANTS INDUSTRIELS

METHOD OF CLEANING CONTAMINANTS FROM INDUSTRIAL COMPONENTS

Abrégé français

Méthode d'élimination d'agents contaminants d'un composant industriel. Une première étape consiste à immerger ledit composant dans un réservoir de prétrempage chimique contenant un agent nettoyant chimique efficace contre les agents contaminants. Le réservoir de prétrempage chimique est maintenu à une température d'au moins 160 degrés Fahrenheit et d'au plus 182 degrés Fahrenheit. Le composant industriel est maintenu dans le réservoir de prétrempage pendant une période suffisamment longue pour amollir les agents contaminants sans que ces derniers ne se décomposent en couches de leurs éléments constituants, tout en élevant la température du composant industriel en préparation au nettoyage. Une seconde étape consiste à exposer le réservoir à des ultrasons à une fréquence d'au moins 80 mégahertz et d'au plus 120 mégahertz.

Abrégé anglais

A method of cleaning contaminants from an industrial component. A first step involves immersing the industrial component in a chemical pre-soak tank containing a chemical cleaning agent effective with the contaminants. The chemical pre-soak tank is maintained at a temperature of not less than 160 degrees fahrenheit and not more than 180 degrees fahrenheit. The industrial component is maintained in the pre-soak tank for a time duration sufficient to soften the contaminants without causing the contaminants to break down into layers of constituent elements, while raising the temperature of the industrial component in preparation for cleaning. A second step involves subjecting the tank to ultrasonic waves at a frequently of not less than 80 megahertz and not more than 120 megahertz..

Revendications

6
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of cleaning bitumen from an industrial component,
comprising the steps of:
immersing the industrial component in a tank containing a
chemical cleaning agent effective to soften the bitumen maintained
at a temperature of not less than 160 degrees fahrenheit and not
more than 180 degrees fahrenheit for a time duration sufficient
to soften the bitumen without causing the bitumen to break down
into layers of constituent elements, while raising the temperature
of the industrial component in preparation for cleaning; and
subjecting the softened bitumen and the industrial
components in the tank to ultrasonic waves of not less than 80
megahertz and not more than 120 megahertz while varying the
amplitude of the ultrasonic waves.
2. The method as defined in Claim 1, including the further step
of rinsing the industrial component after removal from the tank.

Description

CA 02413899 2002-12-06
TITLE OF THE INVENTION:
Method Of Cleaning Contaminants From Industrial
Components
FIELD OF THE INVENTION
The present invention relates to a method of cleaning
contaminants from industrial components, and, in particular,
bitumen.
BACKGROUND OF THE INVENTION
1G Industrial comb>onents used in the Alberta oil sands
invariably become contaminated with bitumen. This includes
industrial components of equipment used in the extraction
process, such as filters and heat exchanger tube bundles. It
also includes industrial components used on site, such as
scaffolding components.
Attempts to clean these industrial components by other
means have proven unsuccessful. Steam and high pressure
water merely tend to translocate the bitumen; moving the
2_0 bitumen around the industrial component without removing it.
The use of chemical. degreasers has also proven unsuccessful.
SLJ1~1ARY OF THE INVENTION
What is required is a more effective method of cleaning
contaminants from industrial components.
According to the present invention there is provided a
method of cleaning contaminants from industrial components. A
first step involves immersing the industrial components in a
tank containing a chemical cleaning agent effective with the
contaminants. The 'tank is maintained at a temperature of not
less than 160 degrees fahrenheit and not more than 180
degrees fahrenheit. fhe industrial components are maintained
in the pre-soak tank for a time duration sufficient to soften

CA 02413899 2002-12-06
2
the contaminants without causing the contaminants to break
down into layers of_ constituent elements, while raising the
temperature of the industrial components in preparation for
cleaning. A second step involves subjecting the tank to
ultrasonic waves at a frequency of not less than 80 megahertz
and not more than 120 megahertz.
The method, as described above, represents the
culmination of great deal of research into what works and
what does not work. Ultrasonic cleaning will not be
effective, unless the industrial component is pre-soaked in a
chemical cleaning agent to soften the contaminants. The
industrial component m~.zst be at the same temperature as the
temperature range at which the ultrasonic cleaning takes
i~ place. A further purpose of the pre-soak is, therefore, to
raise the temperate of the industrial component to at or near
the desired temperature range. It was found that the
ultrasonic cleaning was not effective at temperatures less
than 160 degrees fahrenheit. However, when the temperature
exceeded 180 degrees fahrenheit the heat began to become
detrimental to the process. At frequencies of less than 80
megahertz the ultrasonic cleaning was not effective.
However, at frequencies in excess of 120 megahertz too much
cavitation took place, tending to destroy the amplitude of
the waves.
Although beneficial results may be obtained through use
of the method, as described above, an even greater
improvement in the cleaning was achieved by varying the
amplitude of the ultrasonic waves. Ultrasonic cleaning is a
product of frequency and. amplitude. By varying the
amplitude, contaminants that would not release from the
industrial component at one amplitude tended to release at
another amplitude.

CA 02413899 2002-12-06
3
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become
more apparent from the following description in which
reference is made to the appended drawings, the drawings are
for the purpose of illustration only and are not intended to
in any way limit the scope of the invention to the particular
embodiment or embodiments shown, wherein:
FIGURE 1 is a side elevation view, in section,
illustrating a scaffolding component being pre-soaked in
preparation for ultrasonic cleaning in accordance with the
teachings of the present invention.
FIGURE 2 is a side elevation view, in section,
illustrating an ultrasonic cleaning step in accordance with
the teachings of the present invention.
FIGURE 3 is a perspective view illustrating a rinsing
step in accordance with the teachings of the present
invention.
DETAI?~ED DESCRIPTION OF THE PREFERRED EMEODIMENT
The preferred method of cleaning contaminants from an
industrial component will now be described with reference to
FIGURES 1 through 3. Bitumen will be used as a specific
example of a contaminant that can be effectively removed in
accordance with the teachings of this method. Scaffolding
components will be used as a specific example of industrial
components that can be effectively removed in accordance with
the teachings of this method.
Referring to FIGURE 1, a pre-soak step involves
immersing scaffolding components 10 in a tank 12 that
contains a chemical cleaning agent 14 effective with bitumen.
Chemical cleaning agent 14 is maintained at a temperature of
not less than 160 degrees fahrenheit and not more than 180
degrees fahrenheit. In the illustrated embodiment, tank 12
is equipped with a heater 16 with a temperature controller 18

CA 02413899 2002-12-06
4
for heating chemical cleaning agent 14 to the appropriate
temperature. Ultrasonic cleaning will not be effective,
unless scaffolding components 10 are pre-soaked in chemical
cleaning agent 14 to soften the contaminants. Scaffolding
!. components 10 are maintained in tank 12 for a time duration
sufficient to soften bitumen without causing bitumen to break
down into layers of its constituent elements, while raising
the temperature of scaffolding components 10 in preparation
for cleaning. Scaffolding components 10 must be at the same
temperature as the temperature range at which the ultrasonic
cleaning takes place for ultrasonic cleaning to be effective.
A period of approximately 2Ct minutes of soaking scaffolding
components 10 in tank 12 is usually sufficient. There are a
variety of chemical cleaning agents 14 commercially available
which are known to be effective in the softening bitumen.
Chemical cleaning agents 14 will, therefore, not be further
described.
Referring to FIGURE 2, tank 12 is then subjected to
'?0 ultrasonic waves 28 of not less than 80 megahertz and not
more than 120 megahertz while varying the amplitude of
ultrasonic waves a?8. At frequencies of less than 80
megahertz, ultrasonic cleaning is not effective and at
frequencies in excess of 120 megahertz too much cavitation
takes place which tends to destroy the amplitude of
ultrasonic waves 28. In the illustrated embodiment, an
ultrasonic generator 30 is provided for supplying ultrasonic
waves 28. A controller 32 is provided on ultrasonic
generator 30 for varying t:ne amplitude of ultrasonic waves
28. By varying the amplitude, contaminants that would not
release from scaffolding components 10 at one amplitude tend
to release at anothE:r amplitude. Exposure of scaffolding
components 10 to ultrasonic waves 28 for a period of
approximately 30 minutes has been found to be sufficient.
Care must be taken not to over expose scaffolding components

CA 02413899 2002-12-06
10, as excessive exposure to ultrasonic waves 28 will cause
bitumen to breakdown z.nto constituent elements. Once the
bitumen breaks down into constituent elements translocation
tends to occur.
Referring to FIGURE 3. a further step includes rinsing
scaffolding components 10 afte r their removal from tank 12.
Rinsing of scaffolding components 10 aids in removing bitumen
particles that were freed during cleaning, it also serves to
remove any remaining chemical residue. Rinsing can be
accomplished with a stream of water 34 from a hose 36.
In this patent document,, the word "comprising" is used
in its non-limiting sense to mean that items following the
7.5 word are included, but items not specifically mentioned are
not excluded. A reference v o an element by the indefinite
article "a" does not exclude the possibility that more than
one of the element is present, unless the context clearly
requires that there be one and only one of the elements.
GO
It will be apparent to one skilled in the art that
modifications may be made to the illustrated embodiment
without departing from the spirit and scope of the invention
as hereinafter defined in the Claims.

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