AIR FILTRATIONSYSTEM SOLUTIONS

DRY FILTER SYSTEMS FOR APPLICATIONS USING MINIMUMQUANTITY LUBRICATION (MQL)THE TASK

Minimum quantity lubrication (MQL) is a variation of dry cuttingor machining. This technology has been gaining in popularityover the last few years. Minimum quantity lubrication useslubricants only where they're really needed, at the actual cutting point of the tool. Previous methods required the use ofhundreds of liters of cutting fluids per hour for lubricating, cooling and removing metal shavings. Luckily these days areover. MQL requires only about 50 milliliters per hour or less, atiny fraction of the previous amounts. The advantages are clear:Eliminating the flow of cutting fluids and the need for reconditioning them as well as the minimized cost for theirdisposal result in overall cost savings. In addition the workingconditions improve, workplace safety is notably increased andthe burden on the environment is reduced.

But even minimum quantity lubrication produces emissions -with components of evaporated cooling lubricants, liquid particles and dust - which must be collected and separated.

ADVANTAGES– No auxiliary filtration agents– No filling necessary and no labor expenses– Minimal maintenance requirements– Less waste (hazardous waste)– Increased workplace safety– Reduced environmental risks

INDUSTRIES– Metal machining and processing– All industrial cutting processes

THE SOLUTION

Depending on the proportion of dust to cooling lubricant theresulting substance can be highly adhesive resulting in cloggedfilters. Many suppliers can solve this problem only with a pre-coating process that periodically applies an auxiliary filtration agent to the filter. This agent bonds with the adhesivedust and both are then filtered out together. The downside ofthis process are the additional substances introduced into thecoolant cycle which increase handling costs, maintenance andthe amount of waste eventually to be disposed, thus in turnincreasing overall operating costs.

Keller Lufttechnik's innovative solution - used with great suc-cess in the machine tool and automotive industries - takes a different track. The filter systems developed by KellerLufttechnik work dry and remain permeable without pre-coating. They do not use any auxiliary filtration agents, translating into cost advantages for you.

Several sizes of our surface filters L-Cut, VARIO and PT are inuse, each with a special filter material designed specifically forMQL use. We have the right filter material for every type ofapplication. The air flow respectively the volume of filtered airremains constant during operation.

2

ADDITIVE-LESS EXTRACTION WITH CERTIFIED EXPLOSION PROTECTION TECHNIQUE

When aluminum is dry-machined or treated with MQL expertsare faced with special challenges, such as when a machinemalfunction produces swarfs. If the risk assessment shows thatan explosive dust-air compound exists, an ignition could be possible. Until now it has been a common practice to keep apossible explosion under control by means of a solid, pressure-resistant construction or by means of large quantities of additives which minimize the risk of explosion.Keller Lufttechnik disposes of two different proceedings depending on the application:

1. ProSens: Avoidance of ignition sources2. ProVent: Constructive explosion protection with flameless

pressure relief and decoupling of the pipeline

The complex handling of limestone powder is omitted for solidinertization for both proceedings. Advantages compared toother concepts are the low maintenance, clean and cost-savingtechnology.

At the dry machining with MQL the explosion protection technique ProSens with the "avoidance of ignition sources"can be applied. The filter system is equipped in a way that thereis no danger of ignition sources. The inlet of possible ignitionsources is controlled via an ignition source control. The systemsonly cleans in interval times so that a possible entry of ignition sources is avoided. If the "ignition source control" is activated,the impulse to clean is avoided.

We applied for a patent with this proceeding.

For ProSens the German TÜV Süd Industrie Service (GermanTechnical Inspection Agency) prepared an extensive hazard analysis taking into consideration the explosion risk.

avoidance of ignitionsources

Dry machining with MQL:Explosion protection technique

ProSens

PATENT APPLIED.

NEW!

ADVANTAGES– Single and multiple extraction– No auxiliary filtration agents = low operating costs– Low investment costs– Inlet of ignition sources is controlled = no constructive

explosion protection necessary– 3-shift operation possible– At MQL with flashing point > 150 °C, lubricant supply

each machining unit: at least 10 ml/h– Retrofitting to entire dry machining possible

to machine 50 %

supply air

return air

container providedby the customer

3

Constructive explosion protection measures ProVent are usedat dry machining without any lubricants.

In the event of an explosion at the flameless pressure relief, therelief valve opens so that the pressure in the filter housing canonly increase to a maximum explosion excess pressure (complies with the housing stability). By means of a specialflame filter, a flame escape is avoided whereby the pressurerelief can happen into the workroom. Thus, the system installation is very flexible. The technical decoupling in case ofan explosion of the suction pipe happens via the return valve"ProFlap" where explosion pressure and flame can be

decoupled. With the patented monitoring package of the"ProFlapPlus" considerably less maintenance is necessary compared to customary return valves.

The protective systems used for this concept are approved andcertified according to EU guideline 94/9/EC (ATEX 95).

For ProVent the German TÜV Süd Industrie Service (GermanTechnical Inspection Agency) prepared an extensive hazard analysis taking into consideration the explosion risk.

back pressureflap ”ProFlapPlus”

relief valve

Dry machining with and without MQL:ProVent

ADVANTAGES– Single and multiple extraction– No auxiliary filtration agents = low operating costs– Continuous operation possible– Highest safety standards also at complete dry machining

Flameless pressure reliefDecoupling ProFlap

to machine 50 %

supply air

return air

container providedby the customer

Keller USA, Inc.54 Great Hill Road, P.O. Box 546Naugatuck, CT 06770 USAPhone (203) 729-0145 . Fax (203) 729-0148E-mail: info@kellerusa.comwww.kellerusa.com

AIR FILTRATIONSYSTEM SOLUTIONS

© K

elle

r Luf

ttech

nik

- all

right

s re

serv

ed.

Sub

ject

to m

odifi

catio

ns.

2009

-09

MACHINE

Fire risk through machine or product

Yes

Damage to persons to be expected

Material and ecological damage to be expected

No

No

Yes

Yes

No

Low material orecological damage

Average materialor ecological

damage

High material orecological damage

At least manually operated

extinguishingsystems

At least fire detectorsin connection withmanually operated

extinguishing systems

At least danger alarmin connection with

automatic extinguishing systems

No measures

REFERENCES OPERATORSAUDI BMWDAIMLER FORDGETRAGHEIDELBERGER Druckmaschinen

ALFINGCHIRONGROBHELLER MAG POWERTRAIN

REFERENCES MACHINE MANUFACTUERS

A fire can easily emerge through combustible filter media. Therisk of fire can increase through extracted lubricants and dusts.

Explosion protection measures can prevent fire for example ifinternal ignition sources are avoided. However, this does notmean that a fire can be excluded in general. The selection offire protection measures can be made after a risk analysisaccording to EN 13478.

Depending on each customer request we offer the following fireprotection measures:

FIRE PROTECTION MEASURES

Avoidance of ignition sources in the system

Minimization of the fire load by means of even filter elements(Dust storing is minimized)

Detection of an entry of external ignition sources

Appliance for a riskless entry of extinguishing agents(Utilization of manual powder extinguisher)

Fire detection for filter system with- system shutdown- immediate interruption of the volume flow via fast closing shutoff damper- interruption of the compressed air supply

Automatic Argon extinguishing system including shutoff dampers attached on the clean gas and raw gas side

System with explosion protection technique

"Avoidance of ignition sources"

System with constructive

explosion protection

optionally

optionally optionally

optionally optionally

FIRE PROTECTION

: already integrated standardly optionally: can be retrofittet

HONSELOPELPEUGEOTVWZF

Risk analysis of the fire danger according to EN18478