Graco BetaCell 241D, Операция

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Metering The purpose of the metering pump is to meter the material in precise
quantity and deliver it to the pour gun under sufficient pressure to affect the
proper mix.
The pump for the Pre Polymer component is a seal-less rotary piston pump
driven by a magnetic coupler. This system represents a precise and
completely leak free metering system that does not require any periodic
maintenance.
The metering pump of choice for the Curative component is a
Gusmer
continuous delivery piston pump uniquely designed to provide extremely
accurate and pulse-less flow.
Both pumps are protected on the inlet side by a bag filter, a low-pressure
switch and a temperature monitor. Should the pressure at the inlet fall
below the factory set minimum (40 psi), both pumps will automatically
stop and be accompanied by audible and visual alarms.
The pumps are protected on the outlet side by a pressure switch factory set
to 1200 psi. Should this pressure be exceeded, both pumps will
automatically stop and be accompanied by audible and visual alarms.
The pumps are controlled by a closed loop vector drive receiving dual
inputs from a precision flow meter and a motor mounted encoder to
accurately maintain the operator set point of output and ratio. The Curative
flow meter is protected on the inlet side by a fine mesh filter.
Pre-Heaters
To assure proper mixing of the chemical system, it is necessary to heat both
the A and B components prior to delivery to the pour gun. The
Gusmer
HyBrid style pre-heaters assure efficient and accurate temperature control.
A thermal limit switch mounted to the face of the heater protects the pre-
heaters. Should the surface temperature of the heater reach 220
°
F, the
heater will automatically stop and be accompanied by audible and visual
alarms.
The temperature of the heater is operator set and maintained by a PID loop
in the PLC.