Untitled

154
Chemical pump
enclosure
Acid
ALK
Small diameter chemical loop
RET
RTD
Cond
RES
Drain
Drain
Recycle
LS
Recirc
tank
Return
Water
Overflow
that the control software input is the “true” amount being delivered to the circuit,
without regard for the small quantity being routed through the chemical loop.
Figure 7illustrates an alternate configuration to that of Figure 6for the small
diameter chemical loop. In this case, the CIP system is of an eductor-assisted twotank
design, with separate fresh water tank and motive recirculation tank, which
receives both rinse and recirculated wash water fromthe CIP return. Accordingly,the
slipstream starts at abranch tee in the CIP supply pump discharge line preceding the
FE and reenters at anozzle on the head of the motive recirculation tank.
Figure 8 illustrates direct chemical injection from a pressurized header,
without the use of achemical loop. Concentrated chemical is directed through a
small-diameter ( 1 ⁄ 2 in.) discharge manifold to anozzle at the CIP system recirculation
tank from the facility alkali and acid header. The chemical discharge manifold
begins with an automatic shutoff valve (V1-A &B). Amanual needle-type control
valve (CV-A & B) is pre-set during commissioning to provide the required
restriction for aslow feed of the needed chemical quantity over several minutes.
Amanual shutoff valve (HV-1A &B)blocks can block forward flow. This shutoff
valve used in conjunction with apair of calibration taps (HV-2A &Band HV-3A
&B)isused for off-line calibration of the FE.
Twodifferent FE types are illustrated on Figure 8. The alkali header supplies a
magnetic FE, which is suitable for cleaning chemicals that are conductive. For
nonconductive concentrated CIP chemicals, amass FE can be used and this is
illustrated on the acid header.
TOV
AB
VM
Restrictor
CIPS
pump
T
CIPS
CIPR
Steam
Lebowitz
FIGURE 6 Illustration of asmall diameter chemical loop (1 in. diameter or less) slipstream with
return to CIP return line.