2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
P33 SIMuLATION OF ChEMICAL FACTORS IN
wORKING ENVIRONMENT
ALEnA PAULIKOVá and RUŽEnA KRáLIKOVá
Technical University in Košice, Mechanical Engineering
Faculty, Department of Environmental Studies and Control
Processes, Park Komenského 5, 041 87 Košice, Slovak
Republic,
ruzena.kralikova@tuke.sk
Introduction
Mechanical engineering has not got so many environmental
impacts as chemical industry but its technologies often
use various chemicals to improve its operations. Working
environment of mechanical engineering is also a subsystem
of global geosphere environment.
People spend so long term that they identify this working
environment with their microenvironment. People are
often influenced by several factors in this “small world” of
them. These factors categorize some working activities from
point of view the environmental and health risks. The categorization
of our working activities involves the known details
about factors of work and working environment.
At industry plants there is most of workers exposed to
a combination of multiple factors of working environment
which influence their health and comfort. The category is
determined separately for individual factors but there is no
methodology of working activities assessment for any combination
of individual factors 1 .
By means of modern software simulation there is designed
the methodology with the look-up functions of program
Vensim for a complex assessment of working environment in
specific conditions of mechanical engineering enterprises.
Chemical Parameters in Cutting Process
In cutting processes there are a lot of chemical parameters
which improve or make worse human working environment.
These chemicals exist in various form and states. The
liquids and aerosols create predominant part of the states.
C u t t i n g F l u i d s
Cutting emulsion is a dispersion system of two insoluble
liquids. One creates microscopical drops dispersed in the
other liquid. At machining only emulsion type: oil in water is
used. Milk appearance or transparent appearance depends on
size of oil drops. For the first case the drops are larger and for
the second case the drops are smaller than 10 mm 3 .
Mineral oil and water almost do not generate an emulsion.
That is why the other component is needed – emulator
which covers oil drops with absorption coat protecting their
repeated mergence. Soaps, organic amino compounds, sulphonate
compounds and the like are used as emulators.
Mineral oils conditioned with emulators are called
emulsive oils. They also contain anticorrosive, antibacterial
and high-pressure additives. The content of mineral oils in
emulsive oils is 50–75 %.
s402
The second component of basic emulsion compounds
is water which has got very good cooling effect. However,
raw water has got a lot of defaults for a preparation of industrial
emulsions, i.e. presence of limestone and magnesium
which are liquated and they create hard-removable sediments
on metal surfaces. The sediments silt up piping, sieves, tanks
and also seal the functional parts of machinery 2 .
As well the corrosive influences and high contents of
micro-organisms are harmful in water for an emulsion preparation.
An anticorrosive protection is performed by the
anticorrosive additives, i.e. soda, borax, sodium phosphate
or sodium silicate. These additives soft water and decrease
its surface tension. They improve wettability, cooling effects
and create alkaline environment. Alkaline environment is
suitable from point of view an anticorrosive protection of ferrous
metals. There are pH under 9.0 because safety and health
reasons. If pH is higher then there is a damage of protective
coats and rubber parts of machines.
The main default is an inclination to micro-organism
contamination what makes short cutting fluid durability by
decisive way. If there is an emulsion value of pH 9.5 and higher
then micro-organism development is decelerated. However,
in this condition the emulsion is health unsuitable, irritate
skin and airways.
A d d i t i v e B I O S T A T ® f o r C u t t i n g
F l u i d s
BIOSTAT ® is a common name for new generation set
of antibacterial and fungicidal preparations which have been
developed for 8 years in the framework of environment friendly
production.
Preparation set BIOSTAT ® is inorganic origin and its
influence is based on three activity principles:
•
•
•
the strong electrochemical influence of Ag ion operating
directly with energy reaction in an electron-transportation
string of cellular proteins
the irreversible denaturation of sulfhydryl groups of
micro-organism proteins by means of the ion exchange
H by Ag
the strong oxidation possibility of product of BIOSTAT ® ,
which causes the catalytic oxidation H 2 O molecule and
air oxygen generating hydrogen peroxide. Hydrogen
peroxide is fissioned consequently into H 2 O molecule
and oxygen radical 3 .
Determination of Parameters for Model
Simulation software Vensim is a graphical model tool.
By means of it, we can draft, document, simulate, analyse
and optimize various simulation models of industrial technologies.
One of the technologies is also machining with using
of chemicals, which belongs to the difficult tasks solved in
environmental engineering protection.
The keystone of s model imulation is determination and
application of following variables in the sketch with nodes
and connecting curves: