Teledyne ADFM Hot Tap, Инструкция по установке и эксплуатации, Страница: 17 / 116

ADFM® Flow Meter
Section 1 Introduction
1-7
The velocity data from the two profiles are entered into an algo-
rithm to determine a mathematical description of the flow veloc-
ities throughout the entire cross-section of the flow. The
algorithm fits the basic functions of a parametric model to the
actual data. The result predicts flow velocities at all points
throughout the flow. These results are integrated over the
cross-sectional area to determine the discharge.
The key benefit to this approach is that the system will operate
accurately under different hydraulic conditions. As hydraulic
conditions change, the change will manifest itself in the distri-
bution of velocity throughout the depth of flow. As the ADFM is
measuring the velocity distribution directly, it will adapt to the
changes in hydraulics, and generate a flow pattern that is repre-
sentative of the new hydraulic conditions, insuring an accurate
estimate of flow rate.
Figure 1-3 shows a typical Hot Tap installation in a closed-pipe
application. The operation of the Hot Tap Insertion velocity pro-
filer works in the same manner as the Pro20, but for full and
pressurized pipes. Mounted nearly flush with the inner pipe wall,
the Hot Tap sensor is comprised of four ceramics that transmit
and receive the acoustic signals.
Figure 1-3 ADFM Hot Tap beam geometry
Note
For Hot Tap dimensions, refer to Section 2.7.
3
4
1
2
Beam Angles:
10° front-back;
20° to side
Beam Angles:
20° front-back;
30° to side
Beam Angles:
10° front-back;
20° to side Beam Angles:
20° front-back;
30° to side