Newly Developed Diaphragm Pump for Micro-flow Metering in High-pressure Laboratories
For metering tasks in high-pressure laboratories, the highest of precision when conveying defined quantities of substances is a must. Plunger pumps used for this purpose can withstand the high pressure, but they inherently leak.
If the fluids in question are hazardous substances of which no droplet may escape to the outside, that can be a problem. Upscaling can also be less accurate under some circumstances. To address this problem, Lewa has developed the Intellilab, a hermetically sealed high pressure micro-metering pump. With the integrated motion control system the intellilab is a mechatronic design in total.
The objective of this development is the use for metering and conveying tasks for up to 500 bar, especially in high-pressure laboratories, in which new process technologies at small scale are carried out. The Intellilab s predecessors, the K3 and K5 micro-metering pumps that have been in use for decades, were already developed by Lewa. Now the Leonberg diaphragm pump manufacturer has revisited the existing solution from a technical standpoint: The mature pump technology was retained, and equipped with the latest in drive and control technology, the Lewa Intellidrive. This permits highly dynamic regulation of the drive side’s angular velocity so that, in combination with different control structures, the fluid kinematics can be specifically targeted to the needs of the process.
In the table housing there is a pump head built-in that permits to use the special operation of the servo motor to generate low-pulsation volume flows. The metered flow over time can also be modeled nearly arbitrarily. For example, the stroke volume can be quickly filled with the medium to be conveyed, which is then metered slowly and continuously.
Reliable metering and intuitive operation
The principle of the hydraulically coupled metal diaphragm represents the latest technical state of the art, especially for low flow rates. Leakage to the outside and contact of the metered fluid with air are impossible because the impermeable metal diaphragm seals the fluid hermetically against the atmosphere and the hydraulic displacer system. Since the displacement system is based on wear-free, maintenance-free hydraulic oil, stuffing box problems are eliminated. The rigid hydraulic linkage also keeps the influence of the pressure on the metering flow to a minimum.
The Intellilab is therefore primarily used for exact, reproducible metering in the processes of high pressure synthesis and high pressure hydration. Its use would also be possible in the context of mini-plants. The use of the smallest possible experimental structures with correspondingly small metering quantities, particularly in research, also significantly reduces the consumption of materials deposited.
There is also a new, user-friendly interface adapted to the special needs of high pressure laboratories. For example, a timer function and ramp control are supported, and metered flows profiles can be parameterized and later executed. Visualization using a colored touchpad contributes to intuitive operation and simpler evaluation. It is always possible to extend the Intellilab so that multiple devices can be synchronized seamlessly. Field tests with customers should provide additional options for improvement by the end of the year. Series production and market introduction are planned for 2014.
Picture: Lewa Intellilab is a hermetically sealed high pressure micro-metering pump with integrated drive and control systems. It is particularly designed for applications in high pressure laboratories in which new process technologies are developed and verified at small scales. (Image: Lewa)
Source: LEWA GmbH