Regulation of liquid propane injection via remote pump head of LEWA
With the variant of a completely welded reciprocating line, the hydraulic connection between the pump and drive heads remained leak-proof to ensure the reliable drive of the pump head in the tank.
Before biomethane can be supplied to private and industrial customers, its calorific value must first be adapted to the natural gas network. For this purpose, for example, the Prolimix mixer system from Scharr Tec GmbH & Co. KG is used. However in the past, there had been a return of gas and thus also temperature increases in the vessel. That was because common pump models were oversized. The temperature rise resulted in a pressure increase, which led to safety valves coming off and interrupting the whole process.
LEWA has been successfully developing custom pump systems for OEMs for a long time. Terefore a solution could be quickly found with the Ecoflow diaphragm metering pump with the M900 pump head. The entire conditioning plant is more clearly arranged and less susceptible to faults. That is because injection quantity can be corrected by an optional calorific value measurement, as well as the self-regulation of the pump regarding the propane inflow.
In order to solve the main problem of heat input into the propane vessel, the drive unit had to be installed outside the tank. "The biggest challenge was to ensure a tight connection between the pump head and the drive unit," explained Björn Pfitzenmayer, Area Sales Manager at LEWA. Thanks to a completely welded solution, the hydraulic line as a connecting piece between the pump head and the drive head remained leak-proof. As a result, the problem of heat input was successfully avoided and the pressure in the propane vessel remained permanently constant.
In addition, the integrated Ecoflow variant has been precisely matched to the required propane quantity of 150 liters per hour. This reduces the energy required and also improves the efficiency of the conditioning system.
At the same time, the Ecoflow variant is designed for 40 bar and can therefore deliver the propane to the biomethane with a sufficient pressure. This is particularly important because the high pressure means that it can also be fed directly into high-pressure natural gas networks.
Since the Prolimix with the LEWA pump as a central component was installed, there have been no malfunctions: the mixer systems work without interruption. The Ecoflow is precisely matched to the flow rate, provides the required gas pressure and, thanks to the remote design, does not transfer any heat into the propane tank.
Picture: csplan engineering office