mdc salt bath engl mg22632 salzbadvulkani e salt... · 3 in a separate electrically-heated or...

Technical Information

effluent-free and environment-friendly

LCM VulcanoClean – Salt bath plant,for the curing of rubber profiles

LCM – Salt bath plantsfor the curing of rubber profiles

LCM – Salzbadanlagen zum Vulkanisieren von Gummiprofilen

Auswahlhilfe für die richtigeHärteschutzmasse

Modification of existing LCM salt bath plants to the environment- friendly VulcanoClean concept Umbau vorhandener Salzbad-

anlagen auf das umweltfreundliche Durferrit Konzept

Cooling plants for the UHF Technology

Kühlanlagen für die UHF Technologie

Anwendungsbeispiele

Anlagentechnik

Salzbadanlagen zum Vulkanisieren von Gummiprofilen undKühlanlagen für dieUHF-Technologie

Salt bath plants for the curing of rubber profiles and cooling plants for the UHF Technology


be used again. Should a recyclingnot be possible, the salts con-cerned must be dis posed of inaccordance with the local regula-tions. MDC Engineering S.a.r.lwill, of course, be glad to help customers find suitable solutionsto their problems.

In order to meet today's ecologicalrequirements, we have developeda new salt bath technology for curing, which is described in thisbrochure.

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www.mdc-engineering.net

In addition to the introduction ofenvironment-friendly salts for ther-mo chemical heat treatmentprocesses, the periphery of saltbath plant techniques has alsoexperienced some change.

New salt bath plants operate without effluents occurring. Thismeans that the treated parts arerinsed thoroughly, using a mini-mum of fresh water, in a cascadewashing system, and that the rela-tively small amount of rinsingwater can be processed very eco-nomically. The recycled salts can

Newly developed, environment-friendly saltbath curing technique from MDC Engineering, in cooperation withDurferrit® GmbH

In recent years, ecological require-ments have brought about devel-opments which have opened com-pletely new perspectives, also forthe Durferrit salt baths, techno -lo gy of 90 years experience in theheat treatment field and morerecently for the MDC Engineeringwith the VulcanoClean process.

LCM VulcanoClean – Salt bath plant,for the curing of rubber profilesLCM VulcanoClean – Salt bath plant,for the curing of rubber profiles








Anwendungsbeispiele

Anlagentechnik



Salt Bath Curing Plant

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In a separate electrically-heated orgas-fired salt bath furnace, thesalt melt is warmed up to curingtemperature, which is between200°C and 280°C. By means of anelectromotive salt bath pumpespecially developed for this pur-pose, the salt is pumped into thecuring bath through a pipeline oralso by a sprinkler unit.

At the end of the curing salt bathpot, the molten salt runs back intothe supply salt bath via an out let.In this central supply salt baththere is a desludging area with astrainer screen through which thesalt flows back into the pot. At thesame time, floating par ticles,

sludge and carbonates are sepa-rated from the curing salt bath,and can be removed easily.

The curing salt carried out with therubber profiles is concentrated inthe rinsing cascade, solid par -ticles are filtered out, and thereaction foam is (for examplestearites) automatically removed.

By means of an automatically con-trolled pump, the concen tratedsalt solution is pumped out of thewaste water collecting tank andsprayed onto the surface of theseparate supply and regene rationsalt bath.

The rinsing water evaporates, andthe reclaimed salt is again in thesupply cycle.

Described below are the advan-tages of the system comparedwith conventional curing saltbaths:

• The continuous filtering andcleaning of the curing salt bathensures high quality results.

• Almost all the salt dragged outof the bath is regained andreused.

• Spraying system for precuringthe profiles, ensuring a pres-sureless coating of molten saltaround the profiles over a widearea. Blocking up of the spray-ing system does not occur dueto the continuous filtering ofthe molten salt. The sprayingunits are provided with an elec-tric motor which enables themto be moved vertically, so thatnew profiles can be easilyinserted.

• In 2 or 3 further units, poweredrollers or steel bands guide therubber profiles under the sur-face of the salt bath. Theseunits can also be moved verti-cally to enable new profiles tobe inserted.

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• Continuous desludging ensuresthere is no fire-risk due to rubber particles floating in thecuring plant.

Plant design

The classic curing plant is madeup of single units, in which profilerunning speeds of 100 m perminute are possible. Several profiles can run through the plantat the same time.

The following plant design can beregarded as standard:

• Profile inlet band betweenextruder and salt bath, withinfinitely variable drive.

• Feeding the curing plant withmolten salt ensures a uniformtemperature. Fluctuations intemperature due to filling of thecuring salt bath with solid freshsalt do not occur.

• Due to the continuous inlet andoutlet of molten salt, the levelof the curing salt bath remainsconstant, so that the pressureon the rubber profiles is alwaysthe same.

• The supply and regenerationsalt bath can be gas-fired, andis therefore particularly eco-nomical to operate.

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• Behind the unit is the centre-piece of the plant, in other wordsthe regeneration salt bath for thefiltering, the reclaiming of thecarried out salt, and the transferof the molten salt. The rubberprofiles run over this salt bath ina closed tunnel. By means of aspecial nozzle system, most ofthe adhering salt is blown fromthe surface of the profiles intothe salt bath below.

• Subsequently, the profiles arerun through a 3 or 4 tank clean-ing and cooling cascade andleave the plant absolutely saltfree, dry and at the requiredtemperature. They can then beguided on to a winding deviceor a caterpillar drawing device.

• Usually the salt baths arebetween 12 and 30 metreslong, depending on the para-meters requested by the cus-tomer. A further 8 – 10 metresare required for the cascade.

• Modern control systems withconnections to the extruder,and documentation are inaccordance with the DIN ISO9000 ff and can be integratedwithin the plant.

Cleaning cascade

Economical use of this newlydeveloped vulcanizing techniquerequires a high salt concentrationin the rinsing water. To deal with

this, a cascade technology hasbeen developed, which is describedbelow:

The cleaning cascade consists ofthree or four lower tanks which aredesigned as a washing cascade.The rinsing water within the cascade flows in the oppositedirection to that in which the rub-ber profile to be cleaned is beingtransported.

The upper sections are located ontop of the washing cascades. Thedoors of these upper sections canbe opened pneumatically or manu-ally so that when the plant isclosed, the running profile iscleaned by high pressure sprayingin the tunnel.

• In each individual cascade therinsing water is filtered so thatwhen the salt is later reused nomicroparticles are brought intothe curing bath.

Supervisorsystem

By means of PLC all motionsequences, temperature and secu-rity relevant data will be registeredand can be recalled at the opera-tion screen. Sufficient memorycapacity enables the documenta-tion of the treatment process invarious programs. It is possible tointegrate the extruder as well asthe extractor and coiling installa-tion into the system.

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adhering heat transfer salt isremoved and can be regained.

• Water requirements are cutdown to a minimum comparedwith other cleaning procedures.

• The profiles are cooled so thatthey are warm to the touch,even though the amount ofwater used in cooling has beengreatly reduced.

• A concentrated salt solution isobtained in the first cascade sothat the evaporation which fol-lows in the separate Durferritsupply salt bath can be doneeconomically and without harm-ful substances.

The independent cascade areasare separated by means of a com-pressed air curtain in such a waythat the adhering salt-bearing rins-ing water is pushed back into theprevious cascade unit. The dryingprocess is a special function ofthe last air curtain.

This cleaning line is completed bya storage and filter tank as well asa control cabinet. The entire clean-ing cascade is made of stainlesssteel.

The cleaning cascade fulfils thefollowing tasks:

• The profile is washed thorough-ly so that almost 100 % of the

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Waste air

A small waste air cleaning plantconsisting of a fume scrubberused with a cyclone cleans thesalt-bearing waste air, which con-tains salt and organic resi dues,coming from the curing plant.

At high performance an oil sepa-rator system will be connected inseries before the wet scrubber.

At regular intervals, the wastewater which occurs in the fumescrubber is fed back to the curingcycle via the waste water collect-ing tank.

Waste water

At intervals, the highly concentrat-ed salt water from the washingcascade is fed into the regenera-tion salt bath from the waste watercollecting tank. The salt returns inmolten condition to the curingcycle, and the water vapour is discharged above the roof.

Waste salt

Small amounts of carbonates andrubber particles accumulate in thefilter basket of the reclaim fur-nace, which can be disposed of inaccordance with the official regu-lations for the waste managementof solid salt residues, usually practised by Durferrit GmbH forthe salt residues generated byheat treatment of steels.

The Environment

The technological development ofthe process, to meet marketrequirements, has led to the com-pact and space-saving design ofthe Evaclean/Ecoclean system.

These plants are in popular use forthe environment-friendly operationof existing salt bath curing plants.

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• a compact environment-friendlycombination of cleaning cas-cade and salt reclaim furnace

• can be integrated into an exist-ing salt bath curing plant

• continuously cleans and coolsrubber profiles during treat-ment in an excellent way

• returns the carried out salt tothe curing cycle

VulcanoClean system





Modification of existing LCM salt bath plants to the environment- friendly VulcanoClean concept





Anwendungsbeispiele

Anlagentechnik



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Special plants

The picture opposite shows a 75 mlong salt bath which has been builtfor the continuous curing of hosesup to a diameter of 50 mm.

Two hoses of different dimensionsand running speeds can passthrough the curing plant parallel toeach other. During the process,the hoses swim on the surfaceand are covered with molten saltby a special spraying system.

The plant allows a maximumspeed of 30 m/min. In the sub-sequent cooling area of approx.20 m length, the hoses are cooledto room temperature.

Test plant for treating new profiles

The picture shows a mobile testplant for the optimisation of newprofiles and rubber combinations.This plant, with a total length ofapprox. 5 m, consists of a saltbath and water rinse basin.

Inside the salt bath is a steel band system for speeds up to 20 m/min., which moves verti -cally.

At the end of the salt bath there isan infinitely variable drive to assistthe movement of the profiles.

This test plant ensures that theexisting production plants are notused for the introduction of newmixtures and profiles.

Cooling of flocked profiles

A special modification of the cooling technology previously des cribed permits cooling and thorough drying of flocked profiles.

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Based on a total plant length of 2 m, a reduction of 25 kW thermalenergy/hour can be obtained.Combining several cooling blockspermits indi vidual matching of therubber profiles to the runningspeed in relation to the cross- section.

In the past, long water coolingunits were necessary to cool rub-ber profiles cured in micro waveplants and air circulation furnacesdown to room temperature.

Subsequent to the Vulcano cleansystem developed for the cleaningand cooling of the profiles, wehave developed a cooling systemwhich gives the required coolingperformance in extremely shortunits.










Anwendungsbeispiele

Anlagentechnik



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Air cooling plants

A highly effective air cooling unithas been designed for rubber pro-files whose running speeds andcross-sections permit a relativelymild cooling.

In the cooling channel of the plantthere is a fibre-glass band, whosespeed is infinitely controllable andwhich can be adjusted to the running speed of the profile.

The pneumatically operated lidpermits easy inser tion of the profiles.

After closing the lid, the high per-formance cooling blower startsautomatically, and an all-roundintensive cooling takes place.

The compact unit of ergonomicdesign is supplied ready for instal-lation and can be integrated intoan existing UHF plant without diffi-culty.

Technical data of the standard design:

Total length: 9.300 mmWidth: 600 mmHeight of profile inlet: 1.120 mmCross-section of profile inlet: 70 x 40 mm

MDC Engineering6 RUE DE LA PAIX,85100 LES SABLES D'OLONNE, FranceFix Phone : 0033(0)251219449Mobil : 0033(0)607817321

The data contained in this publication arebased on our current knowledge and expe-rience. In view of the many factors that mayaffect processing and application of ourproduct, these data do not relieve proces-sors from carrying out their own investiga -

tions and tests; neither do these dataimply any guarantee of certain properties,nor the suitability of the product for a specific purpose. Any descriptions, draw -ings, photographs, data, proportions,weights etc. given herein may change

without prior information and do not constitute the agreed contractual quality ofthe product. It is the responsibility of therecipient of our products to ensure that anyproprietary rights and existing laws and legislation are observed.

www.mdc-engineering.net E-Mail : [email protected]

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