AAF International Type N RotoClone - Manual (Page 8)

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2. Sludge ejector motor—it is a fractional horsepower, 230/460/60/3,
TEFC motor. Either motor nameplate or inside cover of motor will
contain the connection hookup diagram of the leads.
3. Motor starter—The exhauster motor starter and sludge ejector
motor starter may or may not be supplied by AAF International.
4. Solenoid valve—This valve is normally supplied in the water supply
line. A 1 ⁄
4
" solenoid valve is furnished with Sizes 1 1 ⁄
2
through 16. A
1 ⁄
2
" solenoid valve is furnished with Sizes 20 through 48.
5. Flow switch—It is an electrical interlocking protective flow switch
wired in series with exhauster starter holding coil circuit. This
prevents operation of RotoClone until the solenoid water valve is
opened. In the event of a water supply failure, the flow switch
contacts open and the RotoClone stops. This flow switch is used
only on the Model “SV” water level control.
CAUTION: For some applications, such as incinerators and dryers,
damage to the process or equipment would occur if the RotoClone is
stopped during its operating cycle. In such cases, the flow switch
should be wired to an alarm bell or signal light to indicate a water
supply failure.
I. Water Level Control Options
Supply water makeup for the RotoClone is required because of water
losses from evaporation, sludge removal, and overflow from the
control box. This makeup water will maintain the proper water level in
the unit by entering the RotoClone through the RotoClone/CONTROL
BOX CONNECTION (Figures 5 and 6).
There are three types of water level controls on the Type N RotoClone
Arrangement C, the Model “SV”, Model “SV” with low water safety
control, and Model “A”. Check shipping documents for type of control
supplied and fill in on back cover of this IOM.
1. Model “SV” Control (Figure 5)—This is the standard water level
control for the Type N RotoClone. It prevents operation of the
RotoClone when there is insufficient water flow. It also allows a
continuous water flow over the running level weir, down the
drainpipe, and into the overflow. The water level supply system
contains a fill valve, solenoid valve, strainer, flow switch and flow
control valve. As long as the solenoid valve remains open there will
be a constant water flow into the control box.
The air pressure equalizing hose is connected directly to a port in
the top of the control box. This connection permits the air pressure
on the clean air side of the RotoClone to equal the air pressure in
the control box. Consequently, the water level on the clean air side
of the RotoClone and in the control box will be the same.
2. Model “SV” with low water safety control (Figure 6)—This control
should be used for “light metal” and other explosive dusts. In
addition to the standard “SV” controls, this model contains an
electrode, electrode holder, and a timing relay. It does not use the
flow switch.
The low water safety control prevents operation of the RotoClone if
the water level in the unit is too low.
The electrode and holder are installed in one of the ports on the top
of the control box. This low water safety device is designed to
maintain continuous contact with the water in the control box. If the
water level in the control box drops below the electrode, a 3 minute
timer relay activates. The water level must reach the electrode
within three (3) minutes or the RotoClone fan will shut down
automatically and the RotoClone operation stops.
As long as the unit operates, the solenoid remains open. When the
fan stops, the solenoid valve closes and the water flow to the
control box stops.
The air pressure equalizing hose is attached to a separate port on
top of the control box. This keeps the air pressure on the clean air
side in the RotoClone the same as in the control box. Hence, the
water level in the RotoClone and the control box will be the same.
Whenever makeup water is needed in the RotoClone, the water
continuously drains into the unit through the hose connection in the
bottom of the water level control box.
This model gives a continuous flow of water over the control
box weir same as model “SV”.
3. Model “A” Control (Figure 6)—This control box is used when there
can be no water overflow from the RotoClone. Makeup water will
be added to the system only when the requirement exists. This
control also prevents the RotoClone from operating when there is
insufficient water level.
The water supply system contains a fill valve, strainer, solenoid
valve, electrode, electrode holder, and a timing relay.
The electrode and holder are installed in one of the ports on the top
of the box. This low water safety device is designed to be in
continuous contact with the water in the control box. When the
water level drops below the electrode, the solenoid valve opens to
supply the required makeup water to the system. When the control
box water level is again in contact with the electrode, the solenoid
valve closes and stops the makeup water flow. This prohibits a
continuous water overflow at the weir.
If the water level has not reached the electrode within three (3)
minutes, the timer will turn off the RotoClone exhauster and stop
the RotoClone operation.
Note: Since make-up water is only added to replace evaporated water
losses and sludge removal water losses, dissolved solids will build up
in the scrubbing water which can cause increased rates of corrosion.
It is recommended that the reservoir be purged occasionally and pH
readings be taken once a week (with litmus paper) and adjusted to
6.5–7.5.