System Description; Functional Description - Cold Jet PR350H Pre-Installation

SYSTEM DESCRIPTION

This user's manual covers the Cold Jet PR120H. The main parts are described in the machine structure section. Operating
instructions for add-ons can be found in separate instructions, and are not included in this manual.

Functional description

The main function of the Cold Jet PR120H is to produce dry ice pellets from liquid carbon dioxide.
This is performed by a sequence of operations executed by the Beckhoff Panel PC. The main steps in a normal production
are as follows and refer to PI diagram P294-1-11991-B for Cold Jet PR120H CE and P294-1-16309-A for Cold Jet PR120H
UL:
1. Start up
2. Production
3. Standby
4. Shut down
At every start-up, the hydraulic cylinder =G01-G1-MO1 for extruder piston is extracted to its maximum position to extrude
the CO2 snow in the chamber in case of emergency stop or machine error.
Liquid CO2 is fed from an external CO2 tank (not part of this description – see supplier information) through an insulated
pipe to the Cold Jet PR120H. It is recommended to use a gas separator to eliminate gaseous CO2 from the liquid CO2.
When the hydraulic cylinder =G01-G1-MO1 for the extruder piston is retracted CO2 in valve =W01-Q1 and injection valve
=G01-Q2 will open and purge gaseous CO2 through the chamber, degassing filters and via degassing pipes to CO2 out.
When temperature =W01-TT1 in the liquid CO2 is -14°C, first injection will begin using =G01-Q1 and proceed until the
timer is reached. The degassing valve =G01-Q5 on the extruder chamber will open to reduce chamber pressure before
the hydraulic cylinder =G01-G1-MO1 for the extruder piston will extract until pressure set point is reached and the hydraulic
cylinder will again retract. This will continue until plug thickness set point is reached. When plug thickness is reached,
production will commence.
In production mode CO2 In valve =W01-Q1 and the Injection valve =G01-Q1 will open until the timer is reached. The
degassing valve =G01-Q5 on the extruder chamber will open to reduce chamber pressure before hydraulic cylinder =G01-
G1-MO1 for the extruder piston will extract until plug set point is reached and the hydraulic cylinder will again retract. This
cycle will continue until a different step is selected. During production, it is possible to set Cold Jet PR120H in standby.
When maximum standby time is reached, the Cold Jet PR120H will run a shutdown sequence.
The shutdown sequence ensures that the Cold Jet PR120H is stopped in a proper
position to empty extruder chamber from dry ice snow and avoid moisture in the
extruder chamber. The hydraulic cylinder =G01-G1-MO1 for extruder piston will
extract to maximum position and return to shutdown set point position.
The PR120H is supplied with a cap to be installed on the outlet sprout at production
stop. This will hinder dew from condensating inside the extruder cylinder and filter.
If the cap is not installed at production stops, it can cause damage to vital
components inside the extruder unit. Before production start-up, the cap should be
removed.
PR120H
User's manual
Version: 5
Page: 6 of 26
Date: 09.11.2022