K-Patents PR-21-S - Manual (Page 19)

2 Inline refractometer sensor 13
Selection of location
To decide "Where to mount" use the following criteria:
1. Process pipe is preferred to process vessel, because favorable flow conditions are
difficult to ensure in a vessel.
2. If the process pipe diameter varies, select the position with the smallest diameter
(and accordingly highest velocity). Then the prism keeps better clean. If the pipe is
coned up after a pump, valve or magnetic flow meter, then add a length of straight
pipe before the coning up and mount the refractometer there.
3. If the refractometer is used in a feedback control loop, make the time lag small. E.g.
when a dilution valve is controlled, mount the refractometer as near the dilution
point as possible.
4. If the temperature varies along the process pipe, select the position with the high-
est temperature. Then the risk of prism coating is minimized, because higher tem-
perature means higher solubility and also lower viscosity.
5. Often the position with the highest pressure (= low point in pipe system + after
pump + before valve) has favorable flow conditions without sedimentation or air
trapping risks.
6. The sensor should be conveniently accessible for service.
2.2.2 Mounting examples
For mounting drawing for desired pipe diameter and connection type, contact the rep-
resentative of K-Patents or please visit at K-Patents website www.kpatents.com
No special mounting parts are needed to mount K-Patents Process Refractometer. For
all process pipe diameters just a standard piece of 88.9 x 3.6 steel pipe is used as
adapter. For small process pipe diameters the piece of pipe is sealed in the other end
to form a flow cell. Examples for different mounting option are given in Figure 2.5
(Sandvik mounting STD, LPL and LPS) and Figure 2.6, Figure 2.7 (Flange mounting).
For flanged mounting, the user has to provide the counter flange. For clamp mounting
K-Patents provides a weld-on ring. Flow cells can be supplied by K-Patents.