Pipe 3PE coating line Suzhou SPT Technology Co.,Ltd , https://www.chinatubemill.com
For many years, designers of process industry installations have relied on pumps with ceramic plain bearings. The reason is obvious, this pump can have a long life and requires a small amount of maintenance. However, there are some liquids which, due to their physical properties, cannot reach a long life in use: this liquid is a non-lubricating liquid.
Gather process pumps with carbon or plastic plain bearings have proven to be particularly suitable for chemical applications in this area. Magnetically coupled gear pumps are particularly suitable for transporting hot solvents, acids, bases, water, aqueous solutions, salt solutions and other non-lubricating liquids. For this reason, this type of pump has been used successfully as a process pump in various industrial sectors for a long time:
For example, it is used as a feed pump, a circulation pump and a discharge pump for organic compounds in the chemical and process industries in separation columns, reactors and evaporators. Since the pump can be constructed in a variety of different materials, it can even be used at temperatures up to 300 ° C and system pressures of 300 bar. In addition, it can be used as a dosing pump for acids, bases, solvents and other aqueous solutions in laboratories, small units or pilot plants.
Special chemical or polymer chemical uses a gear pump to feed the extruder with various additives.
This pump is used in the pharmaceutical industry for the preparation of culture fluids. In this application it is even possible to "on-line" the pump with steam after the process.
In a waste incineration plant it is used as a dosing pump for ammonia or urea for direct nitrogen removal.
It is used to transport water, caustic soda and chlorine bleach in water treatment.
The long service life of this type of pump is due to the fact that over the years it has been possible to select suitable materials for a variety of specific applications by communicating with the chemical industry, and on the other hand due to the high precision of the individual structural members. Excellent running performance with extremely low internal friction.
In order to achieve higher temperatures, differential pressures and longer life when transporting low viscosity liquids with a viscosity between 0.1 mPa s (equivalent to methane) and 0.6 mPa s (equivalent to toluene), a new type of DLC slip has been developed. Bearing. It is particularly meaningful to limit the application of the pump in terms of differential pressure and temperature in the past due to the corrosive nature of chemical resistance and the use of Teflon as the sliding bearing material.
Solid combination
Briefly, on a DLC plain bearing, a DLC coated shaft rotates in a quenched stainless steel bushing. The DLC coating is a carbon layer that is firmly bonded to a carrier material (stainless steel). The advantages of this structure compared to ceramics can be summarized as follows:
The surface of the stainless steel is polished to be much smoother than the ceramic surface, thus significantly reducing friction in the pump.
The firmly bonded DLC coating does not chemically decompose, does not crack and peel off, and has good sliding properties when in contact with non-lubricating liquids, which is not available in ceramics. The chemical resistance of DLC coatings is particularly good. For applications on pumps, only the chemical resistance of stainless steel and sealing materials can be matched.
Sudden temperature changes do not cause damage, which is especially important for applications at 300 °C. Ceramics can rupture when the temperature changes suddenly.
Compared to ceramics, DLC coatings are less expensive because they are coated with standard stainless steel shafts and quenched with stainless steel bushings. No expensive tools and structural changes are required.
If the quenched layer or the sliding layer of the material is abraded, the gap in the bearing will be large, and a repair will be performed anyway. Ceramic bearings must also be so.
It is only necessary to note that the maximum precision of the structural components of the pump must be ensured so that the pump can operate stably and in good condition. Gather pumps are available in two series of plain bearings with a delivery capacity of 0.02 to 2000 l/h.
The combination of DLC plain bearings and precision stainless steel constructions creates a new type of magnetically coupled gear pump that is particularly rugged and versatile. It is Gather's latest generation of process pumps for liquid ingredients in the process industry.