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The brandnew animation of the KNOLL progressing cavity pump MX

The progressing cavity pump MX form KNOLL Maschinenbau characterized by it’s modular design and it’s serviceability is the perfect solution for your application.


Impressive appearance for the KNOLL progressing cavity pump – The MX as a suction pump


Apart from numerous applications in which hygienic aspects of the KNOLL progressing cavity pump MX play a central role, the MX can also used in an extremely beneficial manner in KNOLL’s core business. One new application is the use of the MX in KNOLL‘s in-house Test Centre. Here, KNOLL tests the operability of all cooling lubricants and conveying systems.

For the wet test, the tank on the installation to be tested is initially filled with cooling lubricant from a central collection tank. All pumps, valves and other installation components are set to meet customer-specific requirements. This means that the wet testing procedure takes place largely under real conditions. If the installation test is successful, the cooling lubricant is drawn off again by a vacuum suction unit into a vacuum tank. Thanks to its excellent suction performance, the MX is able to draw off the cooling lubricant continuously from the vacuum tank even at a negative pressure of -0.7 bar and to convey it into the sludge tank of the central collection tank.

Small dirt particles, e.g. welding debris, which may have entered the installation during the production process, are no problem at all to the MX. From the sludge tank, the cooling lubricant is then routed to the attached KNOLL filter for thorough processing. When the cooling lubricant has been filtered, the circuit closes and the purified cooling lubricant is available once again in the central collection tank for a further wet test.

Without the use of the MX, the vacuum suction unit would require a considerably higher tank capacity. The vacuum would also have to reduced regularly to ensure that emptying with a conventional pump is possible.


RONDO FOOD relies on KNOLL – the MX delivers the goods in the pet food industry

Rondo Food_LogoThe RONDO FOOD company, which specialises in snack products for cats and dogs, has been using MX progressing cavity pumps by KNOLL for a number of years now with highly satisfactory results. RONDO FOOD has made an international name for itself as a supplier of private label products to commercial and industrial enterprises in the European, US and Asian markets.

When it comes to the production of pet snacks, RONDO FOOD places great emphasis on fast and hygienic processing of fresh meat. The meat is made into a slurry with a viscosity of between 1,000 and 3,000 mPas. This slurry contains chunks of meat 1.5 x 0.5 mm in size. Gentle product delivery is very important because these chunks must not be destroyed. This unique feature of the MX progressing cavity pump by KNOLL is a key criterion for RONDO FOOD. Today, nearly 50 MX progressing cavity pumps are used by RONDO FOOD at various production sites so as to ensure maximum customer satisfaction.

The MX also has other advantages in addition to gentle product delivery: the proven EvenWall® technology of the high-compression stator allows pressures of up to 10 bar per pressure cycle, which saves space and, most importantly, cost. That means KNOLL can also supply small and cost-effective MX progressing cavity pumps for high-pressure applications. Due to the stringent hygiene requirements which apply in the pet food industry, cleaning and maintenance are important to RONDO FOOD. In this department, the MX scores highly with its service-friendly design. Thanks to its modular principle, it can be disassembled easily and quickly. The MX progressing cavity pump by KNOLL is at home in the hygiene sector and can be easily cleaned and sterilised using CIP and SIP methods by virtue of its virtually pocket-free design. Another plus-point is the low part diversity – which greatly simplifies both maintenance and stocking of parts by the customer. Because the pumps in the MX series differ from one another only in terms of their pump unit, which comes in nine different sizes, the wear parts of, say, the shaft seal and universal joint are identical and can be used flexibly.



KNOLL’s MX does not heat up even at 140 °C

The MX progressing cavity pump from KNOLL is used in many different areas, from the food and beverage industry to pharmaceuticals to the chemical industry. This pump also stands the test in extreme cases. This has been proven at Europe’s leading manufacturer of building shells, interior fittings, and insulation technology. Here, the MX is incorporated into the process of reclaiming fibrous plasterboard. It withstands temperatures of 140 ° C and an extremely abrasive fluid.

Progressing cavity pump MXWaste and remains of the plasterboard panels are relegated to a viscous suspension of approx. 500 mPas. Using the MX, this fluid is pumped back into a reactor before it is processed into new fibrous plasterboard. A challenge of this use is the high temperature of the fluid, 140 °C. Thanks to its special design, the MX performs well: the EvenWall® technology of the KNOLL stator guarantees even pressing even at high temperatures. This improves the durability of the stator considerably. Another challenge of the fluid is its abrasive character. The plaster suspension contains 10 – 15 µm particles with a concentration of 32 – 50 %. The MX also has the solution for this: a stator of wear-proof special elastomer for high temperatures as well as a specially-coated rotor, which also demonstrates wear-proof qualities despite the extremely abrasive fluid.

An additional benefit of the KNOLL MX progressing cavity pump is the even flow speed in the suction housing, which prevents sedimentation and thus the settling of the fluid. This is the result of the even diameter of the cardan joint and the pump’s design, which keeps the clearance volume low. Therefore, no fluid accumulations form on the joint or on the housing wall.

Rotary piston pumps were used for this process in the past, however without any success. After just a few weeks, the pumps had to be replaced due to wear. The MX progressing cavity pump from KNOLL has been used for six months already and shows no traces of wear.

Efficient antipasti production using KNOLL progressing cavity pumps

Progressing cavity pumps from KNOLL Maschinenbauare used world-wide in various sectors. In addition to being used for processing paints and lacquers, chemical or pharmaceutical products, they are the pumps of choice in the foodstuffs industry in particular. The versatile MX can be used in many processes, for example as a dosing pump or transfer pump or for the plastification of media. KNOLL has developed the MX plastifier version specially for plastifying highly viscous to compacted media – an application in which it offers a number of advantages.

A german manufacturer of antipasti products has greatly simplified its production process by using the MX P version. The filling of olives, peppers and chilies with fresh cheese was a very complex and time-consuming process before the introduction of the MX. Each individual husk had to be filled manually using a pressure system.
Used in combination with the dosing system from a south German plant manufacturer, the MX50P-80/10 allows olives, peppers and chilies to be filled fully automatically – all in a single operation. 100 fillings are possible per dosing cycle.

The hard fresh cheese, which is stored in 10 kg buckets and cooled to 6°C, is collected by the pump from the large top-mounted hopper and plasticized to a viscid product with the aid of the feed screw and a special hopper geometry. Stuffing of the fresh cheese products is achieved by co-ordinated operation of the feed screw and pump assembly. This allows air to escape upstream of the pump assembly, preventing air from being trapped in the fresh cheese.

This efficient system has been in operation for several years now and has simplified and improved the working process for the producer.

Processing adhesives with the MX vacuum pump

A well-known Swiss adhesives manufacturer is an important supplier to the international automobile industry of glues for bonding car bodies, windscreens and dashboard kits. Air trapped in the adhesive would allow gaps in the sealing contours, which in turn would result in leakage inside the vehicle due for example to the ingress of rainwater through the windscreen. The adhesive must therefore be absolutely free of trapped air in order to ensure a continuously tight adhesive bead. For this reason, the adhesive is manufactured under vacuum and delivered to automobile manufacturers in vacuum-sealed drums.

For this application, an MX50R-80/20 with an electric heating jacket and dry run protection was placed below a vacuum mixer. The MX is used as a mixer discharge pump and fills the drums with adhesive under vacuum. A vacuum of 20 mbar absolute is maintained in the mixer. In this process, the filling time of the moisture-reactive adhesive including 800 µ filtration is about 4 minutes per drum.

The feed housing and the conveyor worm of the progressing cavity pump MX from KNOLL have a special nanotechnology-based non-stick coating to avoid unwanted bonding effects and bridging. Due to the highly abrasive properties of the medium and high viscosity values ranging from 700,000 – 1,500,000 m Pas, a solid stator made of a specially hardened material is used for this pump. The KNOLL solid stator uses the tried and tested “half-shell system” employed in the production process for the KNOLL screw spindle pumps type KTS.progressing cavity pump with solid stator

The pump was tested for vacuum tightness for a week prior to delivery, and it was found that the high vacuum level remained absolutely constant. 

In this specific application, our competitors’ pumps achieved a maximum life of only approx. 3 months and showed the first signs of wear after only a few weeks. The MX by KNOLL Maschinenbau GmbH has already been in use for more than 16 months and so far has not shown any signs of wear.

Agressive media and a robust pump

There are applications, e.g. in the chemicals industry or in the paints and lacquers industry, where elastomers cannot be used. Pumps would be susceptible to chemical attack, particularly when using mixtures of different solvents. Therefore, not only the medium itself but also the cleaning process must be taken into consideration when designing the pump.

In this case, a viable alternative would be to use PTFE (Teflon) both in the secondary seals and in the stator. KNOLL Maschinenbau recently assembled an MX20 for a south German paints manufacturer to meet its special requirements of suitability for use in paints production and frequent cleaning with a mixture of solvents. Given that these solvents are recycled, their composition and concentration may change, but this must not alter the properties of the eccentric screw pump.

To this end, the MX20 was fitted with a solid stator made of Teflon. The excentric movement of the rotor is compensated by a titanium torsion bar. No elastomer seals are used. As a result, the MX, first, has the required level of resistance to cleaning with solvents and, second, retains its KNOLL trademark properties:

  1. High ease of servicing even when using non-standard components;
  2. Good cleanability (CIP and SIP);
  3. Excellent pump characteristics (low pulsation, high pressures, suitability for high viscosity levels).

In the case of this special version, attention was also given to preserving the modularity of all key components so that the paints manufacturer can, when necessary, adapt the pump to changing conditions within the manufacturing process.

All in all, this MX20 is a great example of how KNOLL Maschinenbau responds flexibly to its customers’ needs to facilitate their manufacturing processes as best possible.

KNOLL at the PROCESS EXPO in Chicago

From November the 1st until 4th 2011 the exhibition PROCESS EXPO takes place in Chicago, Illinois. KNOLL exhibits in the North Hall, booth 848 – you are invited to visit us at our booth.

PROCESS EXPO is the premier worldwide trade show for leaders in the food and beverage industriy. At this fair, all is about sanitary installations.

 KNOLL will present the new developed double spindle pump DSP as well as the different MX-pump sizes. Of course, all important special versions of MX are shown: the hopper version and the submerged version.(to unload drums)

We are looking forward to your visit.

Easy to Service: KNOLL’s MX-Pumps

Among the key requirements of a pump is its ease of service. This matters not only for the maintenance or replacement of wear parts but also for cleaning. Many manufacturing processes require the pumps to get fully dismantled after each cycle or batch of production.

This is no problem for progressing cavity pumps from KNOLL. The MX series is designed for easy maintenance and a quick replacement of wear parts so that the Mean Time To Repair (MTTR) can be kept as short as possible.

In the smaller series (MX10 and MX20) the assembly and disassembly is facilitated by means of clamping closure. In addition to that the pumps can also be opened at each break point without the necessity to disassemble the entire pump. On the larger models DIN screws (union connections) are used for rapid component disassembly and reassembly.

On all models the rotating unit can be dismantled through a service window and thus the pump can be pulled apart. In this way, the seal between the suction housing and bearing frame is made readily accessible.

The rotating unit of rotor and stator can as well be removed easily and quickly or be reinstated because only the interface to the suction casing and the rotating unit must be resolved through the service window. An elaborate double twist of the stators with chain tongs at is part of the Eccentric KNOLL of the past.

Disassembling a pump of the MX series and reassembling it is no puzzle as each part fits exactly to its pre-defined design space. As a result of this there is no wrong assembly of this pump. What’s more: Non-slip cylindrical connection elements prevent any unintended release of pump components.

Progressing cavity pumps from KNOLL therefore offer a perfect combination of sophisticated technology for the transportation of highly viscous media and satisfaction of all requirements for easy servicing. The handling of the pump therefor is fast and easy.

Why KNOLL’s MX-Pumps rely on EvenWall

A very important feature of KNOLL’s progressing cavity pump is their stator with EvenWall®-technology. The following presentation demonstrates why this technology is so important and helpful: