Test section "Variable Gas Injection"

Variable Gas Injection
Variable Gas Injection
DN 200

A further test section of the TOPFLOW facility is the so-called Variable Gas Injection, which is equipped with 18 injection units at 6 different heights. Each unit has three annular gas distributing chambers, from which the gaseous phase enters the test section via a number of orifices in the pipe wall. These holes are equally distributed over the circumference. In the upper and lower chambers 72 orifices of 1 mm diameter are drilled, the central chamber has 32 orifices of 4 mm. The use of gas injection orifices of different size allows to influence the primary bubble size and to study its influence on the flow structure.

The decision to install two chambers with 1 mm orifices was taken to allow in finer variation of the inlet length close to the sensor location – here the axial distance between the upper and lower rings is still comparable to the distance of the entire port from the sensor –, as well as to give the possibility to extend the gas flow rate that can still pass through the small orifices by switching two of them parallel.

In the upper field of the test section, 2 wire-mesh sensors DN 200 are installed for recording the current forms.

The achievable combination of inlet lengths (between 221 and 7802 mm) can be seen in the left figure.

Injection module of the Variable Gas Injection
Injection module

Sectional drawing of an injection module
Sectional drawing of
an injection module