ACS 100, 380 M3, 170, 255, 255 CMF User Manual
...
MDB Series Dehumidifying Dryers
Operation and Installation Manual
50, 100, 150, 255 CMF (85, 170, 255, 380 M3/hr)
Part Number:
Bulletin Number: DRY1-685
Effective: September 1, 2012
882.xxxxx.00
Write Down Your Serial Numbers Here For Future Reference:
_________________________ _________________________
_________________________ _________________________
_________________________ _________________________
We are committed to a continuing program of product improvement.
Specifications, appearance, and dimensions described in this manual are subject to change without notice.
DCN No. ____________
© Copyright 2013
All rights reserved.
ii
Shipping Info
Unpacking and Inspection
You should inspect the large dehumidifying dryer for possible shipping damage.
Thoroughly check the equipment for any damage that might have occurred in transit, such as
broken or loose wiring and components, loose hardware and mounting screws, etc.
In the Event of Shipping Damage
According to the contract terms and conditions of the Carrier, the responsibility of the Shipper
ends at the time and place of shipment.
Notify the transportation company’s local agent if you discover damage.
Hold the damaged goods and packing material for the examining agent’s inspection. Do not
return any goods before the transportation company’s inspection and authorization.
File a claim with the transportation company. Substantiate the claim by referring to the agent’s
report. A certified copy of our invoice is available upon request. The original Bill of Lading is
attached to our original invoice. If the shipment was prepaid, write us for a receipted
transportation bill.
Advise customer service regarding your wish for assistance and to obtain an RMA (return
material authorization) number.
If the Shipment is Not Complete
Check the packing list as back-ordered item s are noted on the packing list. You should have:
Large Dehumidifying Dryer
Bill of lading
Packing list
Operating and Installation packet
Electrical schematic and panel layout drawings
Component instruction manuals
Re-inspect the container and packing material to see if you missed any smaller items during
unpacking.
If the Shipment is Not Correct
If the shipment is not what you ordered, contact the shipping department immediately. For
immediate assistance, please contact the correct facility located in the technical assistance section
of this manual. Have the order number and item number available. Hold the items until you
receive shipping instructio n s.
iii
Returns
Do not return any damaged or incorrect items until you receive shipping instructions from the
shipping department.
Credit Returns
Prior to the return of any material authorization must be given by the manufacturer. A RMA
number will be assigned for the equipment to be returned.
Reason for requesting the return must be given.
ALL returned material purchased from the manufactu rer returned is subject to 15% ($75.00
minimum) restocking charge.
ALL returns are to be shipped prepaid.
The invoice number and date or purchase order number and date must be supplied.
No credit will be issued for material that is not within the manufacturer’s warranty period and/or
in new and unused condition, suitable for resale.
Warranty Returns
Prior to the return of any material, authorization must be given by the manufacturer. A RMA
number will be assigned for the equipment to be returned.
Reason for requesting the return must be given.
All returns are to be shipped prepaid.
The invoice number and date or purchase order number and date must be supplied.
After inspecting the material, a replacement or credit will be given, at the manufacturer’s
discretion. If the item is found to be defective in materials or workmanship, and it was
manufactured by our company, purchased components are covered under their specific warranty
terms.
iv
Table of Contents
CHAPTER 1: SAFETY .............................................................. VII
1-1 How to Use This Manual .......................................................................................... vii
Safety Symbols Used in this Manual .................................................................. vii
1-2 Warnings and Precautions ........................................................................................ ix
1-3 Responsibility ............................................................................................................ x
General Responsibility ......................................................................................... x
Operator Responsibility ........................................................................................ x
Maintenance Responsibility ................................................................................ xi
Reporting a Safety Defect .................................................................................. xii
CHAPTER 2: GENERAL INFORMATION ................................ 13
2-1 Models Covered in This Manual ............................................................................... 13
2-2 Necessary Documents ............................................................................................. 13
2-3 General Description ................................................................................................. 13
Specifying a Drying System ...............................................................................14
What is Desiccant? ............................................................................................14
The Process/Regeneration Cycle .......................................................................15
Aftercoolers, Pre-Coolers, and Plasticizing Traps ..............................................15
Closed Loop and Heat Recovery Option ............................................................16
Process Heat Recovery Option ..........................................................................16
Modular Convey Options ....................................................................................16
Material Overdrying Protection ...........................................................................16
Safety Devices and Interlocks ............................................................................17
2-4 Standard Features ................................................................................................... 18
Mechanical Features ..........................................................................................18
Electrical Features .............................................................................................18
2-5 Options .................................................................................................................... 19
2-6 Dimensions and Specifications ................................................................................
..........................................................................................................................20
2-7 Silo Dehumidification System .................................................................................. 21
20
CHAPTER 3: INSTALLATION .................................................. 22
3-1 Positioning Your Dryer ............................................................................................. 22
3-2 Making Electrical Connections ................................................................................. 22
3-3 Checking for Proper Blower Rotation ....................................................................... 22
Three-Phase Models ..........................................................................................22
3-4 Process Air Connections Between the Dryer and Drying Hopper ............................. 24
3-5 Connecting Cooling Water to the Optional Aftercooler/Precooler and Closed Loop
Regeneration ..................................................................................................................... 24
Installing Water Lines ...........................................................................................24
3-6 Drying Hopper ......................................................................................................... 25
Removing the Rust Inhibitor ..................................................................................25
Air Trap Considerations ........................................................................................25
3-7 Positioning Your Dryer ............................................................................................. 25
v
CHAPTER 4: CONTROLS ........................................................ 26
4-1 Controller Descriptions ............................................................................................ 26
4-2 Operating the Dryer ................................................................................................. 26
4-3 DryPro Data Entry.................................................................................................... 28
4-4 Single Hopper Dryer Setup ...................................................................................... 28
4-5 Single Hopper Dryer Operation ................................................................................ 35
4-6 Program Upgrade Procedures ................................................................................. 41
PLC Program Upgrade .........................................................................................41
Dryer & Drying Hopper Faults .............................................................................................. 43
Alarm List ...........................................................................................................44
4-7 Multi-Hopper Dryer Control Operation ...................................................................... 45
CHAPTER 5: OPERATION ....................................................... 47
5-1 Pre-Startup Checks ................................................................................................. 47
5-2 Startup ..................................................................................................................... 47
5-3 Shutdown ................................................................................................................ 48
CHAPTER 6: OPERATION ....................................................... 49
6-1 Work Rules .............................................................................................................. 49
6-2 Servicing Process Air Filters .................................................................................... 49
6-3 Servicing the Dew Point Monitor .............................................................................. 52
6-4 Symptoms of Worn Desiccant .................................................................................. 52
6-5 Replacing Worn Desiccant ....................................................................................... 53
6-6 Replacing the Process Heater ................................................................................. 55
6-7 Replacing the Regeneration Heater ......................................................................... 56
CHAPTER 7: TROUBLESHOOTING ........................................ 57
Determining Temperature Controller Errors or Sensor Errors ...................................59
CHAPTER 8: APPENDIX .......................................................... 60
8-1 Technical Assistance ............................................................................................... 60
Parts and Service Department ...........................................................................60
Sales and Contracting Department ....................................................................60
8-2 Annex B Information ................................................................................................ 60
8-3 Parts Diagrams ........................................................................................................ 62
vi
Chapter 1: Safety
1-1 How to Use This Manual
Use this manual as a guide and reference for installing, operating, and maintaining the mid-sized
dehumidifying dryer. The purpose is to assist you in applying efficient, proven techniques that
enhance equipment productivity.
This manual covers only light corrective maintenance. No other maintenance should be undertaken
without first contacting a service engineer.
The General Information section outlines models covered, standard features, and safety features.
Additional sections within the manual provide instructions for installation, pre-operational
procedures, operation, preventive maintenance, and corrective maintenance.
The Installation chapter includes required data for receiving, unpacking, inspecting, and setup of
the mid-sized dehumidifying dryer. We can also provide the assistance of a factory-trained
technician to help train your operator(s) for a nominal charge. This section includes instructions,
checks, and adjustments that should be followed before commencing with operation of the dryer.
These instructions are intended to supplement standard shop procedures performed at shift, daily,
and weekly intervals.
The Controls and Operations chapters include a description of electrical and mechanical controls,
in addition to information for operating the dryer safely and efficiently.
The Maintenance chapter is intended to serve as a source of detailed assembly and disassembly
instructions for those areas of the equipment requiring service. Preventive maintenance sections
are included to ensure that the dehumidifying dryer provides excellent, long service.
The Troubleshooting chapter serves as a guide for identification of most common problems.
Potential problems are listed, along with possible causes and related solutions.
The Appendix contains technical specifications, drawings, schematics, parts lists, and available
options. A spare parts list with part numbers specific to your machine is provided with your
shipping paperwork package. Refer to this section for a listing of spare parts for purchase. Have
your serial number and model number ready when ordering.
Safety Symbols Used in this Manual
The following safety alert symbols are used to alert you to potential personal injury hazards.
Obey all safety messages that follow these symbols to avoid possible injury or death.
DANGER indicates an imminently hazardous situation that, if not avoided, will result
in death or serious injury.
WARNING indicates a potentially hazardous situation or practice that, if not avoided,
could result in death or serious injury.
CAUTION indicates a potentially hazardous situation or practice that, if not avoided,
may result in mino r or moderate injury or in property damage.
vii
Dryer Safety Tags
Hazard Alert Symbol
Description/Explanation
Preventative Maintenance
High Voltage Hazard. The
Every six months inspect all
Auto start Hazard.
Every month inspect all
Hot Surface Hazard.
Every month check heater
Mandatory Symbol
Description/Explanation
Read Operators Manual. This equipment must be operated and
Lock Out. This equipment is operated with 3-phase electrical
electrical enclosure is supplied
with 3-phase electrical power.
Use caution when using or
maintaining this product.
Equipment may start at any
time. Lock out/tag out
before servicing the
machine.
When the unit operates
above 212F (100C) the
surface of the unit may
reach excessive
temperatures. Use caution
when using or maintaining
this product.
electrical connections for
secure attachment. For
further information see the
Maintenance Chapter in this
manual.
electrical connections for
secure attachment and that all
warning labels are in place.
For further information see
the Maintenance Chapter in
this manual.
elements for continuity using
an ohmmeter. For further
information see the
Maintenance Chapter in this
manual.
maintained by properly trained personnel. The information
contained within this manual must be read and understood prior to
operating this equipment.
power. Therefore, when performing any maintenance operations
we recommend following the local standards for performing a
lock-out/tag-out procedure.
viii
1-2 Warnings and Precautions
Our equipment is designed to provide safe and reliable operation when installed and operated
within design specifications, following national and local safety codes. This may include, but is
not limited to OSHA, NEC, CSA, SPI, and any other local, national and international regulations.
To avoid possible personal injury or equipment damage when installing, operating, or maintaining
this equipment, use good judgment and follow these safe practices:
Read and follow these operation and installation instructions when installing,
operating, and maintaining this equipment. If these instructions become
damaged or unreadable, additional copies are available from the manufacturer.
Follow all SAFETY CODES.
Wear SAFETY GLASSES and WORK GLOVES.
Work only with approved tools and devices.
Disconnect and/or lock out power before servicing or maintaining the equipment.
Use care when LOADING, UNLOADING, RIGGING, or MOVING this
equipment.
Operate this equipment within design specifications.
OPEN, TAG, and LOCK ALL DISCONNECTS before working on equipment.
You should remove the fuses and carry them with you.
Make sure the equipment and components are properly GROUNDED before you
switch on power.
When welding or brazing in or around this equipment, make sure VENTILATION is
ADEQUATE. PROTECT adjacent materials from flame or sparks by shielding with
sheet metal. An approved FIRE EXTINGUISHER should be nearby and ready for
use if needed.
Do not restore power until you remove all tools, test equipment, etc., and the
equipment and related components are fully reassembled.
Only PROPERLY TRAINED personnel familiar with the information in this
manual should work on this equipment.
We have long recognized the importance of safety and have designed and manufactured our
equipment with operator safety as a prime consideration. We expect you, as a user, to abide by the
foregoing recommendations in order to make operator safety a reality.
ix
1-3 Responsibility
These machines are constructed for maximum operator safety when used under standard operating
conditions and when recommended instructions are followed in the maintenance and operation of
the machine.
All personnel engaged in the use of the machines should become familiar with their operation as
described in this manual.
Proper operation of the machine promotes safety for the operator and all workers in its vicinity.
Each individual must take responsibility for observing the prescribed safety rules as outlined. All
warning and danger signs must be observed and obeyed. All actual or potential danger areas must
be reported to your immediate supervisor.
General Responsibility
No matter who you are, safety is important. Owners, operators and maintenance personnel must
realize that every day, safety is a vital part of their jobs.
If your main concern is loss of productivity, remember that production is always affected in a
negative way following an accident. The following are some of the ways that accidents can affect
your production:
• Loss of a skilled operator (temporarily or permanently)
• Breakdown of shop morale
• Costly damage to equipment
• Downtime
An effective safety program is responsible and economically sound.
Organize a safety committee or group, and hold regular meetings. Promote this group from the
management level. Through this group, the safety program can be continually reviewed,
maintained, and improved. Keep minutes or a record of the meetings.
Hold daily equipment inspections in addition to regular maintenance checks. You will keep your
equipment safe for production and exhibit your commitment to safety.
Please read and use this manual as a guide to equipment safety. This manual contains safety
warnings throughout, specific to each function and point of operation.
Operator Responsibility
The operator’s responsibility does not end with efficient production. The operator usually has the
most daily contact with the equipment and intimately knows its capabilities and limitations.
Plant and personnel safety is sometimes forgotten in the desire to meet incentive rates, or through
a casual attitude toward machinery formed over a period of months or years. Your employer
probably has established a set of safety rules in your workplace. Those rules, this manual, or any
other safety information will not keep you from being injured while operating your equipment.
Learn and always use safe operation. Cooperate with co-workers to promote safe practices.
Immediately report any potentially dangerous situation to your supervisor.
NEVER place your hands or any part of your body in any dangerous location.
NEVER operate, service, or adjust the dryer without appropriate training and
first reading and understanding this manual.
x
NEVER try to pull material out of the dryer with your hands while it is
running!
Before you start the dehumidifying dryer, check the following:
• Remove all tools from the dryer;
• Be sure no objects (tools, nuts, bolts, clamps, bars) are laying in the
area;
If your dryer has been inoperative or unattended, check all settings before
starting.
At the beginning of your shift and after breaks, verify that the controls and
other auxiliary equipment are functioning properly.
Keep all safety guards in place and in good repair. NEVER attempt to
bypass, modify, or remove safety guards. Such alteration is not only unsafe,
but will void the warranty on your equipment.
When changing control settings to perform a different mode of operation, be
sure selector switches are correctly positioned. Locking selector switches
should only be adjusted by authorized personnel and the keys removed after
setting.
Report the following occurrences IMMEDIATELY:
• unsafe operation or condition
• unusual dryer action
• leakage
• improper maintenance
• NEVER stand or sit where you could slip or stumble into the
dehumidifying dryer while working on it.
DO NOT wear loose clothing or jewelry, which can be caught while working
on the dryer. In addition, cover or tie back long hair.
Clean the dehumidifying dryer and surrounding area DAILY, and inspect the
machine for loose, missing or broken parts.
Shut off power to the dryer when it is not in use. Turn the switch to the OFF
position, or unplug it from the power source.
Maintenance Responsibility
Proper maintenance is essential to safety. If you are a maintenance worker, you must make safety
a priority to effectively repair and maintain equipment.
Before removing, adjusting, or replacing parts on a machine, remember to turn off all electric
supplies and all accessory equipment at the machine, and disconnect and lockout e lectrical and
pneumatic power. Attach warning tags to the disconnect switch and air shutoff valve.
xi
When you need to perform maintenance or repair work on a dehumidifying dryer above floor
level, use a solid platform or a hydraulic elevator. If there is a permanently installed catwalk on
your dryer, use it. The work platform should have secure footing and a place for tools and parts.
DO NOT climb on the dehumidifying dryer, machines, or work from ladders.
If you need to repair a large component, use appropriate handling equipment. Before you use
handling equipment (portable “A” frames, electric boom trucks, fork trucks, overhead cranes) be
sure the load does not exceed the capacity of the handling equipment or cause it to become
unstable.
Carefully test the condition of lifting cables, chains, ropes, slings, and hooks before using them to
lift a load.
Be sure that all non-current carrying parts are correctly connected to earth ground with an
electrical conductor that complies with current codes. Install in accordance with national and
local codes.
When you have completed the repair or maintenance procedure, check your work and remove
your tools, rigging, and handling equipment.
Do not restore power to the dehumidifying dryer until all persons are clear of the area. DO NOT
start and run the dryer until you are sure all parts are functioning correctly.
BEFORE you turn the dehumidifying dryer over to the operator for production, verify all
enclosure panels, guards and safety devices are in place and functioning properly.
Reporting a Safety Defect
If you believe that your equipment has a defect that could cause injury, you should immediately
discontinue its use and inform the manufacturer.
The principle factors that can result in injury are failure to follow proper operating procedures
(i.e. lockout/tagout), or failure to maintain a clean and safe working
xii
Chapter 2: General Information
2-1 Models Covered in This Manual
This manual provides operation, installation, and maintenance instructions for 50, 100, 150 and
225 cfm Dehumidifying Dryers with DryPro control. Model numbers are listed on the serial tag.
Make sure you know the model and serial number of your equipment before contacting the
manufacturer fo r pa rts or se rv ice.
Our dehumidifying dryers are designed to generate heated, dehumidified air at carefully
controlled temperatures for use in closed-loop plastic drying systems. Moisture removal from
hygroscopic (moisture attracting) plastic pellets is an essential step in the manufacture of highquality plastic products. Our dehumidifying dryers are used to generate very low dew point air
heated to a controlled temperature for drying plastic pellets and regrind.
2-2 Necessary Documents
The documents listed below are necessary for the operation, installation, and maintenance of
Cabinet Series dehumidifying dryers. You can obtain additional copies from the manufacturer.
Make sure that the appropriate personnel are familiar with these document s:
This manual.
The schematic and assembly drawings included in the customer information packet.
The Customer Parts List included in the information packet.
Operation and installation manuals for any optional controls or auxiliary equipment in the
drying system.
2-3 General Description
Moisture removal from hygrosco pic (moistu re at tract in g ) plastic pe llets is an essen tial step in the
manufacture of high-quality plastic products.
Our Dehumidifying Dryers are used by the plastics industry to generate very low dewpoint air
that is heated to a controlled temperature for drying plastic pellets and regrind.
The drying system consists of a dry air source and drying hoppers with process heating controls.
The dry air source controls two primary sub-systems, the process air and the regeneration circuit.
Each dryer has a left and a right desiccant bed so that one bed can regenerate while the other is in
use.
The drying system can be configured for one drying hopper or for as many as 3 hoppers. The
process air heater can be located on the dryer (single hopper only) or on each individual drying
hopper. Heaters that are located on the drying hoppers have their own independent controls.
The Drying System
Dehumidifying dryers force hot, dry air through the resin in the drying hopper where the air picks
up moisture from the material and is drawn back to the dryer.
In the dryer, a desiccant bed strips moisture from the air. The dryer then re-heats dried process
air, and sends it back into the drying hopper to dry material again.
Large Dehumidifying Dryers General Information 13
This system is a closed loop, because ambient (outside) air is never introduced into the process
Ambient
Regen
filter
Regen
bleed
Process air
heater
From
drying hopper
Process
filter
To drying
hopper
Upper valve
Desiccant
beds
Desiccant
beds
Regen heater
Regen heater
Lower valve
Regen blower Process blower
air. See Figure 1. Our dehumidifying dryers use the closed loop system, because the process air
is typically much drier than ambient air, even after carrying moisture out of the plastic resin.
Recycling process air maintains drying efficiency at a consistently high level. (see
Figure 1).
Figure 1: Air Flow Diagram.
Specifying a Drying System
There were many variables considered in the selection of your drying system, including: type of
materials, residence time, throughput of the extruder or injection molding machine, ambient air
moisture and temperature, and the altitude at the processing site. Should your operating
environment change, we can advise you on necessary equipment, process time and temperature
modifications.
What is Desiccant?
Desiccant is a material that attracts and holds (absorbs) water from the air. The desiccant our
dryers use is a synthetic crystalline metal aluminosilicate that is blended with a clay binder and
formed into beads.
General Information 14
Absorbed water is driven from saturated desiccant by heating it to a high temperature (reducing
the desiccant's capacity to hold water) and forcing air through it. This moisture removal process is
called "regeneration".
The Process/Regeneration Cycle
Our dehumidifying dryers have two desiccant beds. While one bed is on-line in the process air
loop, the other is off-line being regenerated.
When a desiccant bed is on-line, it absorbs moisture from the process air. In time, the bed
becomes saturated with moisture and needs to be regenerated. The dryer automatically redirects
the process airflow to the second bed and starts the regen erat ion cy cle on the firs t bed.
During regeneration, the dryer heats air to over 500°F (260ºC) and forces it through the desiccant
bed. Moisture driven off the bed bleeds to the atmosphere.
If you measure the temperature of the air bled to the atmosphere (bleed temperature), you should
observe a rise after a period of time. This condition, bed breakthrough or bed break, indicates that
the bed is dry. At bed breakthrough, the bleed air temperature peaks between 350°F (176ºC) and
400°F (204ºC). After bed breakthrough the desiccant is hot and needs to be cooled down to avoid
a temperature spike when the beds are switched.
The Dew Point meter measures the dew point of the process air. A properly regenerated bed
produces process air dew point of -40°F (-40ºC) or lower. This ultra-low humidity level is more
than adequate to dry plastics to as little as .003% moisture, depending on the process, material,
and ambient conditions.
Aftercoolers, Pre-Coolers, and Plasticizing Traps
These dehumidifying dryers force hot, dry air through the resin in the drying hopper, where the
High temperature applications (250°F to 400°F / 121°C to 204°C) require aftercoolers to cool
moist air returning to the dryer from the drying hopper. An aftercooler cools the return air by
100°F (38°C); this maintains dryer efficiency and condenses unwanted plasticizers from the airstream. Heat Exchangers are also required (called pre-coolers) when p rocessing materials that
have low drying temperatures (typically 120 F to 150 F / 49 C to 66 C). Check your specific
dryer model technical specifications for actual requirements. Some models have a minimum low
end temperature range that will determ ine actu al requ ir em en ts.
Optional Plasticizer Trap:
• Plasticizer traps should be used when resins are processed in the family of
acetates, butyrates and/or propionates. They should also be used when any
resin (when dried) is known to produce residue, contaminates or volatiles. This
contaminate is trapped in the air stream and is carried back from the drying
process as the air leaves the drying hopper.
• The plasticizer trap will condense the contaminate that is in the air stream and
remove it before it enters the dryer unit. If this contaminant is not removed, it
can foul the desiccant beds and damage mechanical components in the dryer
and in the drying process
• Review your process and confirm with your resin supplier if this will be an
issue. If it is, a Plasticizer trap must be used or it will void the warranty on the
dryer.
General Information 15
Drying Temperature (ºF)
160
180
200
220
240
260
280
300
320
340
360
Set Back Setpoint
130
145
160
175
190
210
225
240
170
260
290
Closed Loop and Heat Recovery Option
After bed breakthrough (see Process/Regeneration Cycle) the desiccant is hot and needs to be
cooled down to avoid a temperature spike when the beds are switched. I nstead of using ambient
air to cool down the desiccant, the closed loop option recirculates a portion of the dry air from the
desiccant bed currently on-line for the process. This approach avoids introducing moisture from
the ambient air normally used to cool down the desiccant, also referred to as “pre-loading”. This
option may be required for high humidity environments.
The closed loop option may use an air to air or a water to air heat exchanger to cool the air before
it passes through the desiccant. If a water to air heat exchanger is used then a water source is
required (see section 3-5)
The heat recovery option utilizes an air to air heat exchanger to pull heat from the exhaust of the
regeneration cycle that would otherwise have been wasted. The recovered heat is then used to
pre-heat the air in the regeneration cycle before it reaches the regeneration heaters reducing the
amount of energy required to heat the air which translates to higher efficiency and lower
operating costs.
Process Heat Recovery Option
In high temperature applications the air returning from the drying hopper is at an elevated
temperature that requires cooling before it returns to the dryer. The process heat recovery option
uses an air to air heat exchanger to pull heat from the air returning from the drying hopper and
then the recovered heat is used to pre-heat the process air before it reached the process heaters.
This reduces the amount of energy required to heat the process air which increases efficiency and
decreases operating costs. Th is optio n is deal for high tem peratu re app lic ation s.
Modular Convey Options
The midsized dryer line are designed to easily add a full range of convey options all of which are
controlled from the dryers touch screen. There are many variables to consider when adding a
convey system including dry air convey, proportioning, hopper and machine convey, among
others. For this reason consult sales who can advise you on necessary equipment.
Material Overdrying Protection
Material Overdrying Protection is an automatic system used to reduce the chance of over-drying,
and possibly melting, the resin in the drying hopper. Material Overdrying Protection activates
when the return temperature is above a set value, indicating that all the resin in the hopper is dry.
The control system monitors the return air temperature and automatically changes the process air
setpoint to the SET BACK SETPOINT value when the return air temperature rises above the set
back temperature. The process air setpoint returns to norm al when the return air temperature falls
below the SETUP TEMPERATURE value. The target values for changing the process air
setpoint can be adjusted on the Mat Protect screen.
Recommended Temperature Settings
General Information 16
Safety Devices and Interlocks
This section includes information on safety devices and procedures that are inherent to the large
dehumidifying dryer. This manual is not intended to supersede or alter safety standards
established by the user of this equipment. Instead, the material contained in this section is
recommended to supplement these procedures in order to provide a safer working environment.
At the completion of this section, the operator and maintenance personnel will be able to do the
following:
• Identify and locate specific safety devices.
• Understand the proper use of the safety devices provided.
• Describe the function of the safety device.
Safety Circuit Standards
Safety circuits used in industrial systems protect the operator and maintenance personnel from
dangerous energy. They also provide a means of locking out or isolating the energy for servicing
equipment.
Various agencies have contributed to the establishment of safety standards that apply to the
design and manufacture of automated equipment. The Occupational Safety and Health
Administration (OSHA) and the Joint Industrial council (JIC) are just a few of the organizati ons
that have joined with the plastics industry to develop safety standards.
Every effort has been made to incorporate these standards into the design of the large
dehumidifying dryer; however, it is the responsibility of the personnel operating and maintaining
the equipment to familiarize themselves with the safety procedures and the proper use of any
safety devices.
Fail Safe Operation
If a safety device or circuit should fail, the design must be such that the failure causes a “Safe”
condition. As an example, a safety switch must be a normally open switch. The switch must be
held closed with the device it is to protect. If the switch fails, it will go to the open condition,
tripping out the safety circuit.
At no time should the safety device fail and allow the operation to continue. For example, if a
safety switch is guarding a motor, and the safety switch fails, the motor should not be able to run.
Safety Device Lock-Outs
Some safety devices disconnect electrical energy from a circuit. The safety devices that are used
on the large dehumidifying dryer are primarily concerned with electrical power disconnection and
the disabling of moving parts that may need to be accessed during the normal operation of the
machines.
Some of the safety devices utilize a manual activator. This is the method of initiating the safety
lock out. This may be in the form of a plug, lever or a handle. Within this lockable handle, there
may be a location for a padlock. Personnel servicing the equipment should place a padlock in the
lockout handle.
General Information 17
In addition to the safety devices listed above, these dehumidifying dryers are equipped with a line
cord plug. This allows the operator or maintenance personnel to unplug the system from its
power source and tag it out. The plug can then be tagged with any number of approved electrical
lockout tags available at most electrical supply stores.
Always disconnect and lockout all electrical power and pneumatic (i.e. compressed air)
sources prior to servicing or cleaning the dehumidifying dryer. Failure to do so may result
in serious injury. No one but the person who installed the lockout may remove it.
2-4 Standard Features
Mechanical Features
Rugged compact frame with sturdy 4” (10cm) casters
Dual blower dryer with dual desiccant beds and electrically actuated valves
180ºF – 300ºF (150ºC) standard drying temperature range
High regeneration temperature control safeties
13X desiccant (molecular siev e)
Easy to access process, regeneration, and combustion air filters
High pressure centrifugal blower
Dew point +55º F to –90º F (13º C to -68º C)
Electrical Features
Electrically-actuated air valves
NFPA79, UL & CUL machinery electrical standards (Electric Dryers) includes:
NEMA 12 controls, components & enclosure
Non-fused electrical disconnect
Solid state relays for process heater control
Branch fusing
Lockable power disconnects
Color touch screen control
Password protection
Temperature display in C or F
Graphical temperature monitor
Data logging option available
Process & Regeneration PID temperature control with auto tune
Dewpoint extend
General Information 18
Available supply voltages of 208, 230, 460, 575/3/60 and 220, 400/3/50
2-5 Options
Options can tailor your dehumidifying dryer system to meet the exact requirements of the drying
task being performed.
Material saver with temperature setback
Process recipes (200 max, over 50 pre-loaded)
Drying temperature
Residence time
Regrind percent
Density
Setback temperature
Throughput calculation
Alphanumeric hopper / process ID
Hour & KWH meters (total & resettable service)
Audible & visible alarm
7 day timer
Sequence shutdown
Aftercoolers for high and low temperature applications.
Audible/visual critical alarm.
Dirty Filter indi c a tor for e a ch individual blower.
Modular hopper stands, hopper banks, and convey systems.
Closed loop regeneration and heat recovery system
Process air heat recovery system
Insulated dryer hose
General Information 19
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