Magnetic drive pumps for highly corrosive media

The new MDK series of plastic-lined magnetic drive pumps is ideal for corrosive and high-purity media in the chemical, pharmaceutical, food processing and waste disposal and recycling industries.

Magnetic drive chemical centrifugal pumps are well established in the chemical engineering sector.

Indeed, the proportion of magnetic drive pumps in such installations overall is steadily growing.

Higher safety standards and the need to cut running costs play a role in this development just as much as the high operational reliability of these pumps.

This applies in particular to plastic-lined magnetic drive centrifugal pumps.

Their major field of application is the conveyance of highly corrosive media and chemicals in the fine chemical and pharmaceutical industries.

One indication of the great significance of this design is, for example, the works standards of the major chemical and pharmaceutical companies.

They specifically prescribe lined magnetic drive pumps.

The plastic-lined magnetic drive pump enjoyed a real boom when the MNK series from ITT Richter Chemie-Technik was launched in 1988.

Since then, plastic-lined magnetic drive pumps have made inroads into applications that neither the pump manufacturer nor the pump operators had expected at that time.

At that time: solids were taboo; there was a great fear of damage from dry-running - one frequently cited reason for not using magnetic drive pump; and the eddy currents generated in metallic cans meant that heat was transferred to the medium, ie a risk of overheating at low flow rates.

However, since than, substantial numbers of MNK series pumps have been operating with solids contents of 10, 20 and more percent by volume.

Richter SAFEGLIDE PLUS has long since become synonymous with extremely effective dry-running protection of SiC plain bearings (0.5h and more).

Non-metallic MNK cans made of CFRP/PTFE prevent eddy currents and thus permit the conveyance of very small volumes as well as media near their boiling points.

Operating temperatures of up to 180C, in isolated cases even higher, do not present any problems.

Flow rates of up to 300mü/h and delivery heads of up to 90m are possible.

And, thanks to a host of accessories as well as safety and monitoring equipment, even extremely critical media and very difficult applications can be readily handled.

Following the success of the MNK pump, product development of lined magnetic drive pumps has been extended to special pumping applications.

For example, the MPB peripheral pump features a novel flexible impeller ring channel gasket.

This pump has even convinced people who have had very bad experience with the products previously available on the market and, in fact, didn't want anything more to do with peripheral pumps.

The MPB solves the major problem of the accuracy of impeller ring channel adjustment.

Vortex pumps MNK-X with an extended housing compartment and special impeller geometry are predestined for conveying media containing very large or long-fibre particles or with high solids contents.

They are also ideal for very high gas contents of up to 5% by volume.

MNK-S self-priming pumps are proven problem-solvers for emptying chemical containers and waste-water basins from the top - even at high back pressures.

With its robust design, the MNK covers virtually every application in the chemical and related process technology sectors - down to very difficult applications.

Now the company has developed a new plastic-lined magnetic drive pump, the MDK series.

Many plant operators tend to have applications and operating conditions of medium to lower difficulty for process pumps, especially in terms of corrosion resistance and operating temperature.

Instead of a universal process pump a magnetic drive pump with a technically more simple design and at a lower cost but with a more limited application range would certainly be an interesting alternative.

The elementary safety features, which have even been adopted now in the chemical engineering sector in the form of a standard for plastic-lined magnetic drive centrifugal pumps, must also be provided even with a lower-priced solution: ie freedom from eddy currents, resistance to dry-running and a robust, metal-reinforced overall design.

With its recently introduced magnetic drive pump MDK, ITT Richter now offers a very attractive design for the medium duty segment.

Fields of application for the MDK include corrosive and high-purity media in the chemical, pharmaceutical, petrochemical, pulp, metal, food processing and waste disposal and recycling industries.

Specifications include: pressure up to 16bar; operating temperature up to 120C with FEP lining or up to 80C with a PP lining; and flow rates up to 80mü/h and a delivery head of up to 60 LC at 2900rev/min.

The MDK was developed for conveying media where customary stainless steels are not sufficiently corrosion-resistant, and as an alternative to pumps made from expensive exotic metals (Hastelloy, monel, titanium etc).

It is also well suited to: pure media where good cleaning possibilities and antiadhesive surfaces are important; environmentally critical media; media near their boiling points where even small rises in temperature could result in evaporation and thus to inadequate lubrication; and for applications where there is a risk of brief dry running, eg when containers are being emptied or where there is a risk of incorrect operation.

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