Constant Conveying of Shear-Sensitive Release Agent
NEMO® progressing cavity pumps allow a smooth production of synthetic rubber
The gently conveying progressing cavity pumps prevent the undesired formation of bubbles.
Look behind the scenes
Approximately half of the 20 million plus tonnes of rubber produced each year is of synthetic origin. Many compounds are available which are just as well suited or even more suitable for various applications than their natural counterpart.
The most common variant of synthetic rubber is styrene-butadiene rubber (SBR). This and butadiene rubber (BR) – another frequently used compound – are produced at a plant in Indonesia that has only recently been opened. At the location in Banten, a province on the island of Java, the aim is to produce 120,000 tonnes of raw material for tyre production annually. Those involved in the project emphasise the efficient production process, which stems from the company’s own procedure, and which is intended to make production more environmentally friendly.
When building and commissioning the new production site, everything went according to plan – with one exception. After all equipment had been installed, one component did not work as required: A centrifugal pump lined with polyvinylidene fluoride (PVDF), which was intended for conveying Promol®. This medium works as a so-called compound separating agent: It prevents unvulcanised rubber compounds from sticking together – an important element in the handling of the compounds produced. The good separating characteristics of Promol® enable low rates of consumption and also ensure that as little separating agent as possible finds its way into the rubber compound. This is important for high-quality further processing.
Soon after starting the system the employees noticed an intensive build-up of bubbles inside the centrifugal pump. The PVDF lining also began to come loose. Long-term usage of the centrifugal pump for conveying was therefore out of question. This led to big problems as the production should start as quickly as possible. This would not be possible without the separating agent to ensure safe transportation of the rubber.
Searching for a quick resolution of the problem, they therefore turned to NETZSCH – with the requirement for a pump to safely convey the Promol® dispersion that was as low-shear as possible. The company, with its headquarters in the Bavarian town of Waldkraiburg, develops and produces various types of pumps, including the NEMO® progressing cavity pump range.
“NEMO® pumps are very robust and particularly suited to shear-sensitive media”, says Antonio Prabandaru, sales manager at NETZSCH Indonesia. The shear forces that act on the media in the pumps are so low that these are even used in the food industry for transporting whole fruits. The continuous and low-pulsation conveyance makes the aggregate suitable for use in many sensitive areas. “Therefore only very minimal foam and bubbles are produced during conveying with the aggregates”, adds Prabandaru. Thanks to these characteristics, progressing cavity pumps are used for many media which have to be conveyed continuously, with resistance to pressure, carefully and with low pulsation.
Another aspect makes the NEMO® pump ideal for deployment by the Indonesian rubber producer: It places great importance on a constant, non-decreasing flow rate – no wonder that, with a lack of separating agent supply, there would be the immediate risk of rubber sheets sticking together and being barely usable for further processing. Progressing cavity pumps convey so precisely that they can even be used for dosing tasks. In this respect too, they are therefore ideally suited to conveying the Promol®.
To solve the problem in Indonesia as quickly as possible, Prabandaru and his team fell back on pumps that were stored in the country. With components permanently available in all important markets, the globally active provider ensures that even urgent orders can be fulfilled as quickly as possible.
“Since the pump was installed in August 2018, our customer has been very satisfied with the aggregate”, says the product manager. “In the future, he also plans to install the NEMO® in other plants where Promol® is conveyed.” Caused by an acute production crisis, a reference project that the customer found convincing across the board therefore came about thanks to credible products and fast service.
NEMO® BY progressing cavity pump
Media: 2% and 20% water dispersion of Promol®
Flow rate: Up to 4 m3/h
Pressure: Up to 7,2 bar
Temperature: Ambient 35 °C
Viscosity: +/- 1.5 cP