EP0101876A1 - Piston pump head of a high pressure piston pump - Google Patents

Abstract

Head having a mechanical or hydraulic drive for delivery pressures above 2000 bar, the head being made of steel which can be hardened by ageing at room temperature. The use of this steel for piston pump heads makes it possible to employ fast running high-pressure piston pumps (number of strokes greater than 60 min<-><1>) for the above delivery pressures since the wear symptoms can be markedly reduced in the piston pump heads and the continuous operation service lives of these pumps can thereby be appreciably increased.

Description

The invention relates to a piston pump head of a high-pressure piston pump with a mechanical or hydraulic drive for delivery pressures above 2000 bar.

Both high-pressure piston pumps and high-pressure diaphragm pumps are used to pump thin-viscosity, non-lubricating liquids to high pressures, especially pressures above 2000 bar.

In both pump types, however, there are disadvantages when pumping thin-viscosity, non-lubricating liquids to pressures above 2000 bar, for example in the case of high-pressure diaphragm pumps, the idle time in continuous operation is too short, caused by the diaphragms breaking. The disadvantage of slow-running high-pressure piston pumps (number of strokes less than 60 min), in turn, is the long standstill of the piston at the end of the pressure stroke and thus the interruption of the delivery flow. This disadvantage has a particularly negative effect when dosing catalysts in the synthesis of high-pressure polyethylene. However, these slow-running units are used because the machine parts are subjected to less stress and the service life of these high-pressure piston pumps is increased. For example, the stuffing box made of soft materials generates less frictional heat and therefore less wear. At the same time, the pressure-bearing parts - particularly the piston pump head - which are highly stressed by extreme pressure amplitudes are less stressed per unit of time. The design of these slow-running high-pressure piston pumps is very large and therefore expensive.

Therefore, it was an object of the invention to further develop the high-pressure piston pumps so that - while avoiding the above Go / P Disadvantages - thin-viscous, non-lubricating liquids can be pumped against pressures above 2000 bar, ie to use fast-running engines (number of strokes greater than 60 min ^-1 ) in order to reduce the design and at the same time increase the service life of the high-pressure piston pumps in continuous operation. In order to achieve the latter, the signs of wear in the piston pump head in particular must be reduced or avoided.

This object is achieved in that the piston pump head is made of age hardenable steel. These are steels with special alloying elements, which, based on an intermetallic compound, reach their high strength with sufficient toughness and corrosion resistance by storing the finished part at 480 ^o C to 600 ° C under inert gas. Specifically, the steel is used 1.4534 and aged at 540 ⁰ C.

The advantages achieved with the invention consist in particular in the fact that when using high-speed high-pressure piston pumps (number of strokes greater than 60 min ^-1 ) to promote thin-viscosity, non-lubricating liquids against pressures above 2000 bar, significantly longer service lives in continuous operation could be achieved.

Claims (2)

1. Piston pump head of a high pressure piston pump with mechanical or hydraulic drive for delivery pressures above 2000 bar, characterized in that the piston pump head is made of age hardenable steel. 2. Piston pump head according to claim 1, characterized in that the piston pump head is made of steel 1.4534.