Cost reduction in cutting oil distribution at 5,000 l/min and 20 bar
Kenfilt modernised the cutting oil distribution system of a Swiss manufacturer using frequency converters and progressive starters with PLC control, reducing energy consumption and noise levels.
Based on more than 50 years of experience in filtration engineering and equipment manufacturing, KENFILT can provide a range of products to update and modernise existing equipment with state-of-the-art technology.
A recent project involved a Swiss KENFILT customer, a metal cutting tool manufacturer, where KENFILT carried out a major upgrade of their cutting oil distribution system for the tool grinding production plant.
The original configuration installed in 1989 and expanded in 1999 consisted of 5 pumps, one of them controlled with a frequency converter that had difficulties maintaining constant pressure in the 20 bar line. Each pump supplies 1,000 l/min at 20 bar with a total oil flow of 5,000 l/min.
The drawbacks of fixed flow are well known: high energy consumption and risk of pressure peaks, due to indefinite pressure situations in the pipes when opening or closing valves in machining and grinding centres.
The first step of the project was to analyse all the customer's working parameters: number of machines, type of machines, individual and total flow rates, working conditions, number of shifts, holiday shutdowns and maintenance requirements.
After a comprehensive engineering study covering mechanical, electrical and process aspects, KENFILT delivered and implemented a turnkey system. The overall approach was to install frequency converters and progressive starters, as well as improving the safety pressure relief valve control to avoid pressure peaks under certain working conditions.
Pump P1 was equipped with the original frequency converter. Pump P2 was fitted with a new 37 kW frequency converter and pumps 3, 4 and 5 with progressive start-up systems. Progressive starters increase line pressure progressively, helping to make pressure control more stable and avoiding pressure peaks.
The cycle works with pumps P1 and P2 regulating the pressure. If the desired pressure cannot be reached, pumps 3, 4 and 5 will start successively until the desired flows and pressures are achieved. Once pressure is reached, the speed of P1 and P2 is automatically controlled to maintain the line constantly at 20 bar.
After several months of operation, the initial project objectives were confirmed: reduction in energy consumption and noise levels, reduction in mechanical stress and higher production quality by always supplying all machines at the correct pressure of 20 bar.