Extraction of Emulsion Mist from various CNC machine tools using central Extraction0 pages

EXTRACTION OF EMULSION MIST
FROM VARIOUS CNC MACHINE TOOLS
USING CENTRAL EXTRACTION

Mauersberger und Fritzsche is an SME with
a long tradition in gear manufacturing for
drive technology and in the production of
high-quality structural steel cupped shears.
The company has CNC machining and milling
centres from renowned manufacturers, such
as Monforts, Doosan, Yang and Mori Seiki,
in which workpieces are cooled, purged and
lubricated with water-soluble cooling lubricants (emulsions).
The task, which the corporate management
adressed to UAS, was to improve the air
climate in the hall using a filter system.

Solution
CNC machining and milling centres and CNC
lathes are cutting machine tools, i.e. a workpiece is shaped by means of material removal
using tools such as borers, cutters, lathes.
The term “lathe” was originally derived from the
workpiece being rotated on a spindle (of an axis).
Today’s “centres” have several axes, in which tools
and workpieces move. Workpiece and tool changers supplement the systems so that complex
geometries can be produced on one machine
tool.
The “CNC” in the name is derived from Computer
Numeric Control, which means that production
processes can be programmed and the programmes stored in the memory of the machine. Ergo,
repetitive production procedures only need to
be called up. There is the tendency to automate
heavily and to minimise interventions by the
operator.
Today’s high-speed processing requires the introduction of cooling lubricants. These are used
to cool the cutting edges on the direct contact
surface to the workpiece during the cutting
procedure, to lubricate the contact surface and
remove any arising chippings through “purging”.
Through the rotation and energy input, the
cooling lubricant forms an aerosol mist at this
moment, which is extremely hazardous to health
if inhaled.

The company’s machinery comprises approx.
10 machine tools. For this reason, the advantages and disadvantages of single-station
extraction units were weighed up against a
central extraction system.
The advantages of a central extraction system
prevailed in this project. On balance, the
investment costs are lower despite higher
costs for piping and assembly, while maintenance is concentrated on a central point.
In addition, a summer/winter set-up as hall
ventilation can be realised easily with this
concept, which permits exhaust air operation
in the summer and a recirculated air operation in the winter to save heating costs. In
general, it is not possible to give one blanket
answer to the question about single-station
extraction units or central extraction systems.
This must be decided on the facts of the relevant plant. However, as a general rule, the
overall or life cycle costs of a central system
with a ventilation system performance from
6,000m³/h tend to be lower.
In this case, a two-staged electrostatic filter is
used as filter, which reliably filters out harmful substances and emulsion mist, such as
aerosols, and offers the client an approx. 15%
reserve for production expansions.
The client was initially sceptical towards the
electrostatic filter solutions as the rumour is
still spreading through the market that “emul-

Client: Mauersberger und Fritsche

E X T R AC T ION OF EMULSION MIS T F ROM VARIOUS
CNC MACHINE T OOLS USING CEN T R AL E X T R AC T ION

Problem