USER GUIDE
FLUID BED DRYER
The Fluid Bed Dryer User Guide
Contents
Chapter 1 - Introduction
Customer Service
Using this Manual
Safety Instructions
Safe use of Instrument
Setting up the Instrument
Instrument Description
Drying Tubs and Accessories
Special notes on accessories
Instrument Components
Applications
Optimal Bed Depth
Basic Principles of Fluidised Beds
The Drying Process
Page 1
Page 1
Page 2
Page 3
Page 3
Pages 4 - 6
Page 6
Page 7
Pages 8 -9
Page 10
Pages 10-11
Page 11
Pages 12 -14
Chapter 2 – Operating Procedure
Operating – Overview
Setting the Conditions
Setting the Timer Control
Setting the Temperature Control
Setting the Blower
Starting and stopping
General
Optional Extras
Humidity / Temperature Probe
Installing a Pulse Flow Device
Operation with a Pulse Flow Device
Page 15
Page 16
Page 16
Page 17
Page 17
Page 18
Page 19
Page 20
Pages 20 -21
Page 21
Page 22
Chapter 3 - Maintenance
General Maintenance
Air filters
Replacement of Flange “O” Ring
Replacement of Outlet Filter on the instrument
Power on Checks
Fuses
Specification
General Advice
Page 23
Page 23
Page 24
Page 24
Page 24 - 25
Page 26
Page 27
Page 28
Introduction
Chapter 1
Customer service
Thank you for purchasing Endecotts Fluid Bed Dryer
If you need spare parts or service please contact your local distributor in the
first instance: or:-
Endecotts Ltd
9 Lombard Road
London SW19 3TZ United Kingdom
Tel +44 (0)20 8542 8121
Fax +44 (0)20 8543 6629
E mail sales@endecotts.com
If you require spare parts please have the following information ready: -
Serial number of the instrument.
Part numbers and /or exact descriptions of the items required.
Quantity required.
Date required and any special shipment request.
Delivery address.
Purchase request / order reference.
If you require technical assistance please have the following information
ready: -
Serial number of the instrument
Description of the problem
Address and telephone number
Contact name
Using this Manual
The information contained in this manual will assist you in getting the best
from your Fluid Bed Dryer. The text accurately describes the original build
specification, the drawings and illustrations are intended for general
reference only and are not necessarily accurate in every detail. Dimensions
and characteristics are not to be changed without prior notice.
- 1 -
Introduction
Chapter 1 (continued)
The user is responsible for updating the manual with any bulletins from
Endecotts and to reflect any changes or modifications made by the customer.
Endecotts cannot be held responsible for the conditions of use and changes to
the instrument that are beyond its control.
No parts of this manual or any other documents supplied with this instrument
may be reproduced or transmitted without the prior written consent of
Endecotts.
Safety Instructions
Throughout this manual the reader’s attention is drawn to specific safety
instructions as follows: -
WARNING!
A warning alerts the reader to a personnel hazard. Failure to act on the
warning may result in death or injury.
CAUTION!
A caution alerts the reader to a hazard. Failure to comply with the
caution may result in damage to the instrument or product.
NOTE:
A note provides additional information that should be given special
attention.
- 2 -
Introduction
Chapter 1 (continued)
Safe Use of Instrument
Endecotts makes every possible effort to ensure that the instruments it
supplies are designed and constructed to be safe and without risk to health
or property when used properly. In accordance with relevant EU Directives,
they are marked with the CE symbol to indicate they comply with all
relevant European safety and hygiene requirements. However, please note,
that instruments can cause injury if you are careless and do not follow the
operating instructions.
Ensure that you and all others working nearby know the location of the
instrument controls and how to use them; especially the front panel
Operations On/Off button and the Power On/Off switch located on the
back of the instrument.
Ensure that you have read the relevant parts of this manual before attempting
to use or work with the Fluid Bed Dryer. For your own safety and those of
others, please ensure the operator or personnel in charge of the location has
received proper training.
Setting Up the Instrument
The instrument will arrive packed in a purpose designed box having a packing
slip. Ensure that all the system components arrive s a f e l y . To f o r m an
o p er a t in g s y st em t h e r e a r e t h r e e components which are
required. The instrument, the tub assembly, and a suitable filter for the
tub assembly.
The location of the dryer should be chosen for the intended use. For use with
samples where dust may be generated or for frequent use on samples with
high moisture content, we suggest positioning the dryer in a fume hood.
The rear panel of the instrument and the underside have air filters provided
for supplying cooling air for the inside of the cabinet. The rear panel also has a
stainless steel mesh filter provided for the inlet air used for drying the sample.
Ensure there is enough space adjacent to these filters to allow air to enter the
instrument.
- 3 –
Introduction
Chapter 1 (continued)
Instrument Description
The dryer is of simple, compact design, conveniently portable and easy to
operate, the only requirement being a mains power supply.
The source of power should be within the reach of the instrument lead so
that no extension wires are required. The instrument contains the air
distribution system, heater element, thermostat, and electrical controls.
There are many types of tub assemblies to choose from which can be used
with the Fluid Bed Dryer. Please contact Endecotts for details.
The FBD incorporating the full range of options is illustrated below. This
dryer enables the operator to have complete control a compile a record of
the drying process. The main components are shown below: -
Air is drawn in through a Stainless Steel Inlet filter in the back of the
instrument and blown by the centrifugal fan over a 2kW electrical heater and
through stainless steel filter gauze at the top of the dryer body. A Pulse Flow
Unit (optional extra) is situated after the inlet filter, which can intermittently
shut the inlet air on and off, which acts as an additional means of fluidising a
difficult sample. A 5 litre sealed glass tub is shown having a tub base
which attaches to the instrument by means of a bayonet fitting. There is an
“O” ring seal between the tub assembly and the instrument. At the inlet of
the tub assembly, there is a 60 mesh stainless steel support filter and a finemesh nylon filter.
- 4 -
Introduction
Chapter 1 (continued)
Instrument Description cont/…
These filters retain the sample in the tub assembly while assuring a uniform
distribution of air enters the assembly. A filter top cap is clamped on to the
top of the tub by means of a clamp and seals on a silicon “O” ring which also
keeps the sample particles from escaping the tub assembly. The wide range
of tub assemblies which are available are designed to match the variety of
sample types and drying applications.
To facilitate the addition of a sample a side port is provided having a
sealing screw cap. In addition to an inlet temperature probe, which is part of
the thermostat control, a temperature / humidity probe is also available for
the outlet of the tub assembly.
The above dryer can be used as a stand alone unit, with full control of
the flow rate, inlet temperature, and time of drying. The values of the inlet
set temperature, actual inlet temperature, outlet temperature and humidity
and time remaining in the drying cycle can be obtained by directly reading
from the front panel.
- 5 -
Introduction
Chapter 1 (continued)
Instrument Description cont/…
DRYING TUBS and ACCESSORIES
The 5 Litre Sealed Glass Tub having a sample port and a sensor port is the
standard tub assembly for the Fluid Bed Dryer. It
allows full utilisation of the analytical, data capture and storage, and
programming control feature on the dryer. There are many
other types of tub assemblies each having their own type of filter which can be
used on the instrument.
TUB ASSEMBLIES AND FILTERS
LARGE TUB ASSEMBLIES
2 LITRE STAINLESS STEEL TUB & BASE
2 LITRE GLASS TUB & BASE
5 LITRE STAINLESS STEEL TUB & BASE
5 LITRE GLASS TUB & BASE
USE LARGE FILTER BAGS AVAILABLE IN NYLON,
TERYLENE, POLYPROPYLENE, AND NOMEX
5 LTR SEALED GLASS TUB & BASE USE TOP CAP FILTERS
AVAILABLE IN SS (60, 250, 500 MESH), 3 MICRON
POLYESTER
MINI TUB ASSEMBLIES
USE FOUR MINI TUBS WITH A MINI TUB ADAPTOR MINI SS TUB
MINI GLASS TUB
USE MINI FILTER BAGS
AVAILABLE IN NYLON, TERYLENE, POLYPROPYLENE, AND
NOMEX
500 350 33 MINI SEALED GLASS TUB
USE MINI DISC FILTERS
AVAILABLE IN NYLON, SS (60, 250, AND 500 MESH),3 3 3
3 MICRON POLYESTER
- 6 -
Introduction
Chapter 1 (continued)
Special Notes on the Accessories
Only the 5 litre glass tub assemblies, both those using filter bags and the sealed
variety, can have an inlet for the outlet humidity and temperature probe. Only
these tubs can fully utilise all the features on the Fluid Bed Dryer.
The glass tubs have an advantage in the operator being able to see the sample as
it dries. The optimum flow rate is easy to select judging by the appearance of the
fluidised sample. The operator is often able to estimate the state of dryness and
guess the shape and size distribution of the particles simply by the appearance of
the sample flowing in the tub. The main advantage of the stainless steel tubs is
durability. High-grade stainless steel is used since the process requirements
usually call for high product purity and good chemical and corrosion resistance at
high temperature. Other specialised tub assemblies which can be used on the FBD
include a Particle Classifier and a Sieve Dryer.
The mini tubs are 250ml in capacity and can be used effectively on samples
weighing from 5 to 50 grams per tub. Four tubs can be dried simultaneously.
The decision to go to sealed tubs is based simply on particle size. Below 45
microns, we suggest you go to a sealed tub.
The 3 micron polyester filters can be used for the mini tubs as well as the 2 and 5
litre tubs. These filters are effective for 5 to 25 micron particles. Please note that
these filters greatly reduce the flow rate of air through the sample. Drying times
normally occurring between 10 to 30 minutes can take up to several hours using
these small pore size filters. Furthermore, the use of these filters may even hinder
the mixing of sample particles during drying. Many of the main advantages of fluid
bed drying may be lost. If in doubt, Endecotts offer to do an initial study on your
sample which will ensure proper accessories are chosen for the application.
A wet sample should occupy about 1/3 of the tub assembly volume. As it dries
and the density drops, the apparent volume will increase to about ½ the volume.
Tubs should be purchased that are 3 x the volume of the sample size.
- 7 -
lower
Set
Value
Cubic
Metres per
Min
Cubic Feet
per Min
Metres per
Second
Feet per
Minute
Litres per
Second
0
0.13
4.59
0.35
68.6
2.17
10
0.32
11.30
0.86
169
5.33
20
0.50
17.66
1.34
264
8.33
30
0.70
24.72
1.88
369
11.67
40
0.89
31.43
2.39
470
14.83
50
1.07
37.79
2.87
564
17.83
60
1.25
44.14
3.35
659
20.83
70
1.45
51.21
3.89
765
24.17
80
1.64
57.92
4.40
865
27.33
90
1.82
64.27
4.88
960
30.33
100
2.00
70.63
5.36
1055
33.33
Introduction
Chapter 1 (continued)
The Instrument Components
The Fluid Bed Dryer incorporates an electrical heater, temperature
controller, timer and a powerful air blower fan. There are, however,
significant improvements over previous models. All the controls on the
front panel are on a printed membrane with pressure controlled contacts
which prevent the ingress of fine powder. The cooling air, as well as the air
for drying the sample are filtered. This eliminates possible faults related to
powder getting inside the instruments and switches.
The air blower is controlled by a thyristor circuit to give a smooth variation
over a wide range of motor speeds, as in previous models. On the
Fluid Bed Dryer, however, the blower motor speed is monitored and a
feedback loop assures the blower motor speed is maintained regardless
of surges in power supply or effects of a heater being switched on and
off. This achieves a more controlled fluidisation and allows us to monitor
the volume of air per time used in the drying process. A seal between the
tub assembly and the instrument ensures all the air that is measured goes
through the sample. Each instrument is calibrated for flow rate output
during manufacturing.
lower
Set
Value
Cubic
Metres per
Min
Cubic Feet
per Min
Metres per
Second
Feet per
Minute
Litres per
Second
0
0.13
4.59
0.35
68.6
2.17
10
0.32
11.30
0.86
169
5.33
20
0.50
17.66
1.34
264
8.33
30
0.70
24.72
1.88
369
11.67
40
0.89
31.43
2.39
470
14.83
50
1.07
37.79
2.87
564
17.83
60
1.25
44.14
3.35
659
20.83
70
1.45
51.21
3.89
765
24.17
80
1.64
57.92
4.40
865
27.33
90
1.82
64.27
4.88
960
30.33
100
2.00
70.63
5.36
1055
33.33
The 2 kW heater element is controlled by a thermostat system. The
maximum achievable temperature is 200 degrees Centigrade, but this is
determined and limited by the flow rate that and the power supply.
- 8 –
Introduction
Chapter 1 (continued)
Warning!
When Operating a Dryer above 65°C we recommend making a copy of the
following warning sign so that it can be displayed next to the instrument
and tub assembly.
Stick on thermal labels can be also provided for all 2 and 5 litre tub
assemblies on request and should be positioned in the most visible location if
the instrument will be he used at elevated temperatures.
The use of microprocessors in the instrument allows us to control the
temperature during heating and cooling the sample to within a few degrees.
Note: Good temperature control is only obtained when a tub assembly is in
position on the instrument. Without a tub assembly, the air flows
without resistance and a wide deviation may be observed between the
set temperature and that actually achieved.
A pulse flow device may be added to the unit as an optional extra. The FBD
has a pulser which is retrofitable and is positioned externally at the air inlet.
- 9 -
Introduction
Chapter 1 (continued)
Applications
The wide range of materials that can be dried includes fine powders, coarse
particles, crystals, granules, slurries or pastes (after decanting, or predrying or by spraying into bed of initially dried material). Samples with
moisture content up to 80% such as some polymers, dyestuffs and molecular
sieves can also be dried with the provision that they remain solid in nature at
these high moisture levels. An operator can also dry heat sensitive materials,
such as foodstuffs e.g. peas, wheat and lentils, since they may be dried at
relatively low temperatures. If traces of volatile organic compounds or
hazardous fumes are generated during the drying process, drying should be
conducted in a fume cupboard.
Warning:-
The FBD is not an explosion proof instrument and therefore samples having
volatile compounds that are flammable or able to reach their flash point
should not be used with this dryer.
Because of the high heat and mass transfer rates obtainable, drying times
for the Fluid Bed Dryer are much less than for the more traditional methods
available in laboratories such as oven or vacuum drying. Many materials can
be dried in less than 15 minutes.
Optimal Bed Depth
The optimal bed depth which is related to the amount of wet sample which
can be used is that at which the sample can be fluidised smoothly at
the required temperature by a set air velocity. This normally is
equal to the sample filling approximately 1 /3 of t h e t u b b e i n g
u s e d f o r d r y i n g . (The advantages of the fluid bed dryer can however
be realised even if the sample lurches and mixing in a non-ideal manner).
As drying proceeds with most samples, the sample becomes less dense and
less sticky” and the bed becomes easier to fluidise. The apparent volume of
the fluidised sample will change from 1/3 (75 mm bed depth) to ½ (150 mm
bed depth) of the volume of the tub assembly. Normally, the air velocity will
be progressively reduced as the sample dries.
- 10 -
Introduction
Chapter 1 (continued)
Due to the complexities of the mixing and drying process, the optimal amount
of sample to use is best determined by trial and error.
The pulse flow works most effectively on “stringy” samples that will not mix,
particularly when they are wet. The short blasts of air from the pulse flow
essentially mixes the sample with each pulse. This is usually only required until
the sample loses its external moisture, after which we find most samples will
fluidise more easily. Using a pulse flow may not show any improvement in
drying more ideal, easier to mix samples.
Basic Principles of Fluidised Beds
When a stream of gas is passed upwards through a bed of material at a certain
velocity the bed will first expand, then become suspended and agitated by the
gas stream to form a fluidised bed.
This has the appearance of boiling liquid due to the formation ofmany small
bubbles at the surface of the sample, the so-called “bubbling fluidisation”.
Ideal fluidisation is achieved only with spherical particles of a narrow size
distribution range and with the appropriate amount of sample with the
optimal flow of gas. The optimum operating gas velocity for bubbling
fluidisation lies above the minimum fluidising velocity but below the velocity
of entrainment of the material. Needless to say, this ideal is not often
achieved with real samples. With real samples and maximum amounts of
material to dry, the other forms of drying are more generally obtained.
At higher gas velocities, larger bubbles and plugs of material are formed
resulting in a more violent type of fluidisation called slugging or spouting.
Particles that are needle shape (have a large aspect ratio) are more likely to
give “spouting fluidisation” with the spout arising from the centre of the
sample and falling back down along the outer surface of the sample near the
tub.
- 11 -
Introduction
Chapter 1 (continued)
The Drying Process
If water is added to a dry sample, it is absorbed by particles until the point
at which the particles become saturated. The saturation point is known as
the Critical Moisture Content.
The CMC is characteristic of the sample material, and the initial water which
is incorporated into the particle is held as internal moisture. If placed in a
sealed container, a sample containing internal moisture will become
homogeneous. The further addition of water past saturation will become
external moisture. External moisture is heterogeneous by nature, being pools
of water lying in between the saturated particles. The drying process
reverses the procedure, as external moisture is first removed.
A bed of wet material fluidised by a heated air stream provides ideal
conditions for drying. The very efficient contact between gas and solid
particles due to the turbulence of the bed results in high heat transfer rates
causing rapid evaporation (mass transfer) of moisture which is carried away
with the exit air. This process has a high thermal efficiency because most
of the heat input is used in vaporising the moisture and the exit air only
rises in temperature as drying of external moisture nears completion.
External moisture is the first to be removed, and it is removed at a rate
controlled by the flow rate and temperature and is not influenced by the
presence of the solid constituent in the sample. Following this, the internal
moisture is removed. The rate of internal moisture removal is usually limited
by the diffusion of water from within the particle, and less directly
influenced b process parameters.
Continuous and thorough mixing of the sample while drying ensures that the
temperature and moisture content are uniform throughout the sample and
the drying process is reproducible and the end product is homogeneous.
- 12 -
Introduction
Chapter 1 (continued)
The Drying Process cont/…
The process can be conducted at relatively low temperatures and there is little
abrasion, since the particles are separated by air bubbles. The drying process
can be analysed to show the amount of internal and external moisture. When
external moisture is removed, drying can be conducted quickly, since the
temperature is kept low by the evaporation of water. When internal water is
removed, drying should be conducted very slowly to give time for the water to
diffuse out of the particles. The temperature control and understanding of the
critical aspects of drying ensures that heat-sensitive materials can be treated
with care.
The knowledge gained from lab scale fluid bed drying is directly applicable to
industrial fluid bed dryers, since the same principles apply. Characterising a
product in the laboratory provides useful information for continuous and
batch scale dryers in the plant. Studies in the lab are useful for designing plant
scale fluid bed dryers.
Typical Applications
1. Drying of a material to a given moisture content using
reproducible drying parameters.
2. Fluidising curves give the variation of pressure drop with air flowrate.
3. Establishing the conditions required to achieve minimum and the
more normal operating fluidisation velocity.
4. Determination of drying curves indicating Critical Moisture to
assess Internal and External Moisture and show feasibility of
fluidised bed drying of a material on an industrial scale. Also
established best industrial scale dryer to use. (Drying curves are
relevant to the mechanism of drying. They may be used as a basis
for heat and mass.
- 13 -
Introduction
Chapter 1 (continued)
The Drying Process cont/…
5. Calculation of hea t tr ansfe r coeff ici en ts for dif f ere nt conditions
relevant to dryer design and comparison of fluidised beds with other drying
methods.
Other applications include: -
Drying small particulates, drying particulates with a wide particle size range,
drying down to a particular moisture concentration, analysis of moisture,
rapid drying, homogenising samples, separating particles based on density,
coating samples, etc.
A most important application of fluid bed drying is determining a drying curve
for a sample. A drying curve, i.e. a plot of moisture loss over time, shows the
drying characteristics of the material. We can derive the drying rate,
constant rate of moisture loss (external moisture) and falling rate periods
(internal moisture), drying times, equilibrium moisture content and critical
moisture content and heat transfer coefficients. All valuable information in
characterising a sample and designing an industrial drying process.
- 14-
Operation
Chapter 2
Operating: - Overview
The Fluid Bed Dryer has been designed to make reproducible drying easy.
The instrument should be connected to the power source and turned on from
the mains switch on the back of the instrument.
When turning the mains power on, all the lights on the front panel flash on
and off while the instrument initialises. Following this, the Version number of
the Software held within the instrument is displayed momentarily (U103 at
time of going to press). The instrument starts up in standby mode,
displaying the last settings for the blower speed, timer and temperature.
The operator can set the functions and power the instrument on and off from
the front panel.
There are four sections on the front panel namely to set the drying time, set the
inlet temperature (SV), set the blower speed and turn the instrument on and off.
Each will be discussed in turn.
- 15-
Operation
Chapter 2 cont/…
Setting the Conditions
In standby mode, the variables of time, inlet temperature and blower
speed can be set prior to running the instrument. There are symbols
indicating the four sections. A blue clock face icon indicates the timer, the
yellow radiation symbol icon indicates the heater, and a fan blade icon
indicates the blower and finally the power section having on/off symbols as
buttons.
If the display for the timer or heater sections are not illuminated when the
instrument is turned on, this simply indicates these functions were not used
on the last occasion when the instrument was operated. They can be turned
on by a short press of their icon buttons.
The set-up procedure for operation consists of the following: -
Section 1 - Setting the timer.
A blue flashing light above the timer icon indicates that the timer is ready to
receive an input setting. Pressing the (+) or (-) positions adds or subtracts
minutes to the timer. The display is hours and minutes, with a minimum
setting of 1 minute and a maximum setting of 9 hours and 59 minutes.
Pressing the blue clock face at any stage turns the timer off. The timer
section is shown below.
Section 1
- 16-
Operation
Chapter 2 cont/…
Section 2 - Setting the temperature.
A green flashing light above the “Heater Symbol” indicates that it is ready to
receive a temperature value. The red light (SV) is illuminated in the lower left
hand corner of the digital display shows that the “Set Value” of the
temperature is being displayed.
Section 2
The (+) and (-) buttons allow the set value to be adjusted from 20.0 up to
199.9 deg Centigrade. Pressing the Heater Symbol at any stage in the
operation of the instrument turns the temperature control off. (see p19 last
para)
Section 3 - Setting the blower.
The blower function always turns on when the power is supplied to the
instrument and the flashing green light above the blower icon flashes
indicating an input adjustment to the blower speed can be made. The (+) and
(-) switches allow adjustment between 2 and 100%, which is displayed. The
blower speed below 10% is considered less accurate in its correlation to an
absolute flow rate).
Section 3
The blower can never be entirely turned off while the instrument is in
operation which is a safety feature which prevents overheating. (The unit also
has an over temperature cut off switch as a further precaution against
overheating).
- 17-
Operation
Chapter 2 cont/…
Section 4 - Starting and Stopping the Dryer.
The dryer can be turned on, to operate according to its pre-set conditions,
by pressing the green switch below the power light. Section 4
Pressing the red switch stops the dryer operation and displays the last set
values. Pressing the start again refreshes the timer which begins counting
down from the original set time. When the dryer reaches the end of a
timed cycle, it automatically goes into standby mode.
The ‘power’ light changes from a yellow colour in standby to a red colour
during operation.
All the (+) and (-) adjustments can be accelerated by holding down the
switches.
- 18-
Operation
Chapter 2 cont/…
General
Several conditions can be modified during a drying procedure. While
operating the FBD, the timer counts down from the set time. It cannot be
altered by pressing the (+) and (-) buttons. The timer function can, however,
be turned off by holding down the icon button. Once off, it can be turned on
again by holding down the icon button yet again. It now starts in the standby
mode and a blinking blue light above the icon indicates the settings can be
altered by the (+) and (-) buttons. Once the correct time has been set, the
timer can be starting by holding down the icon until the blue light stops
blinking.
While operating the unit, the digital display of temperature shows the actual
measured temperature, i.e. Process Value as opposed to the set temperature
it displayed in the standby mode. This I indicated by the little light, indicating
PV, near the upper left corner of the display. The PV indicator light flashes
from green (off) tored (on) indicating the status of the heater.
The Set Value can be displayed by a short press of the (±) or the temperature
icon. The set temperature can be altered by holding down the (±) button as
indicated on the display. The heater can be shut off by pressing and holding
the icon button. It can be turned on again, by pressing and holding the icon
again, and wakes up in standby mode like the timer.
The blower rate can be readily altered at any time while operating the unit.
On stopping the unit, the settings of the timer, temperature, and blower will
all default to the values last set in standby mode.
Since the unit does not have a cooling facility, the minimum temperature
that can be achieved is usually around 30 to 35 degrees Centigrade,
which is limited by the temperature of the intake air and the compression of
the blower.
- 19-
Operation
Chapter 2 cont/…
Optional Extras
There a r e t w o i n s t r u me n t o p t i o n s , t h e fi r s t is th e H u m id i t y
Temperature Probe and the second is a Pulse Flow Device. Both options are
easily retrofitable and can be added on after purchasing the basic unit.
Connecting the Humidity/Temperature Probe
Note: The instrument should be turned off before connecting the H/T Probe.
The h/t probe requires a five litre glass tub with a special port designed to hold
the probe in position within the tub assembly. The probe connector fits into a
special plug in on the back of the instrument. The probe is inserted through a
retaining cap and a silicon washer is inserted into the port on the tub assembly.
(see illustration pg 4) The instrument can be powered up and turned on
immediately after the installation of the probe.
Note: Connectors on the back of the instrument are shipped with plastic covers to
prevent contamination. These covers should be used whenever a connection is
not being used, particularly when the instrument is being used.
Operation with the H/T Probe
The Digital Display for the Temperature, Section 2 of the front panel, also
displays the additional information obtained when using the H/T probe. The
probe measures the humidity and temperature at the outlet of the tub assembly
while the instrument is running. By pressing the heater symbol switch for a short
duration, the display changes from: -
PV = Process Value of inlet temperature (°C). SV = Set Value
of temperature (°C).
T = Outlet temperature measures in tub assembly (°C). rH = Relative
Humidity at Outlet of tub assembly (%).
The new readings being displayed are indicated by lights appearing around the
display. Outlet temperature lights are to the upper right of the display and
Relative Humidity indicator lights are to the lower right.
- 20-
Operation
Chapter 2 cont/…
Operation with the H/T Probe cont/…
During operation, the set value will be displayed for a few seconds and
the display will automatically change back to reading the process value of
temperature. The inlet and outlet temperatures as well as relative
humidity will remain displayed during the operations. While in standby, only
the set value of the inlet temperature will be displayed. This is the only option
which can be displayed in section 2 that can actually be set during
manual operation.
Installing a Pulse Flow Device
To attach a Pulse Flow Device: -
1) Remove the four nuts from the four studs, two of which hold the bracket
containing the stainless steel filter. Remove the SS Filter and bracket.
2) Place four wavy washers on the four studs; followed by the four spacers
provided with the PFD. (The spacers are 3.5cm in length). The spacers should
be made finger tight plus an additional ¼ turn.
3)The PFD should be positioned on the spacers with the on/off switch in the
lower left hand corner, facing the back of the instrument and the power
supply/signal line coming from the bottom of the unit. The PFD should be
pushed tightly against the instrument.
4) The bracket and SS Filter should be placed horizontally across the two
spacers. This may take a little bit of force if the bracket has been distorted at
all 4 wavy washers and 4 self locking nuts (M4 size) should be placed on the
screw threads of the four spacers sequentially and tightened.
5) The cable coming from the bottom of the PFD should be connected to the
15 way D socket adjacent to it .The PFD is now installed.
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Operation
Chapter 2 cont/…
Operation with the Pulse Flow Device cont/…
The PSD can be made to function by simply pressing the on/off switch on
the device downward. The pulsing of the valve occurs in cycles of
approximately 2.5 seconds closed and 2.5 seconds open.
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Maintenance
Chapter 3
WARNING!
Before starting any maintenance procedure on the Fluid Bed Dryer
ensure that the instrument is switched off and disconnected from
the electrical supply and read all the instructions thoroughly. This
is for your safety and to prevent damage to the instrument.
Air Filters
The FBD is designed to be very reliable and requires little routine maintenance
apart from external cleaning. If used in a dusty environment wenm
recommend that the air filters are cleaned regularly to ensure optimum
performance.
There are three filters which are easily accessed on the outside of the
instrument,
namely: The Air Inlet Filter can be found on the back of the instrument. There is a
bracket holding the filter to the Pulse Flow Device (if one is provided) or to the
back of the instrument (if there is no PFD being used).The screws holding
the bracket should be loosened and the filter slid off the instrument. The
filter can be washed in warm soapy water or put into a dish washer. It should
be dried and replaced on the instrument.
To the right of the Air Inlet Filter (as you face the back panel of the
instrument, is a Cooling Air Inlet Filter which allows air to enter the inner
instrument for cooling purposes. It is a flat filter which can be easily removed
and cleaned with a vacuum cleaner to remove dust or blown clean by a clean
air supply in a well ventilated area.
Finally, there is a Cooling Air Outlet Filter which can be found and easily
accessed on the underside of the instrument. This can be accomplished by
placing a protective sheet on the table top next to the instrument and gently
turning the instrument and resting it on its side. This filter can also be cleaned
by a vacuum cleaner, or alternatively blown clean by a clean air supply in a
well ventilated area.
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Maintenance
Chapter 3 cont/…
Replacement of Flange “O” Ring
There is a silicon “O” ring in the flange on the top of the instrument on to
whic h t h e tub a s s e m bli e s s eal . Should t h e instrument develop an air
leak coming from between the tub- assembly and the instrument, this
ring will have to be replaced. It is easily removed from the flange by
carefully prizing it out with a screwdriver or small pair of pliers.
The “O” ring is not really a ring but spongy silicon rubber which is supplied
as a length of cord. The length of cord is 51cm, which appears to be several
centimetres longer than it needs to be.
Note: Do not shorten the length of the silicon cord, but compress the cord into
the groove on the flange while inserting it back.
The compression technique forms a more rigid structure and results in a
better seal.
Replacement of Outlet Filter on the Instrument
The mains power should be disconnected prior to following the procedure
described below. The 60 mesh stainless steel filter can be removed by
unscrewing the three hexagonal screws in the top flange. The filter is
placed between the instrument housing and a fiber glass insulating washer
on to which the flange is positioned.
Removing the filter allows access to the inside of the casting. It is possible to
vacuum out any particulates which may have gotten into this area, but care
should be taken not to move the thermocouple sensor positioned in the
centre of the casting housing.
Power-on checks
Note: Power-on checks should be made with the instrument in manual mode.
The FBD needs a mains electricity supply and must be fitted with a suitable
plug or contactor for its power requirements.
- 24-
Maintenance
Chapter 3 cont/…
Power-on checks cont/…
When switching the power on to the unit from the back of the instrument all 8
LED lights and the 3 digital displays should flash on for five times. The
version of the software used to drive the instrument, “firmware,” is then
displayed for two seconds. (At the time of going to press, the version number
is U103). The instrument then proceeds to standby mode.
In standby mode, the display that is shown will depend on your last
settings. Only those functions, such as time, temperature and flow rate that
have been used on the last shut down will be shown giving their last value.
If a function isn’t displayed, it can be turned on by pressing the function
button. The LED next to the activated function’s symbol should be flashing to
indicate that the operator can now alter the setting of that function.
In standby mode, the power button light is on and displayed in a yellow
colour. If the instrument is turned on by pressing the ON switch on the front
panel (I), all the function lights stop flashing and the power button light
becomes red.
Note: While in operation, the functions of blower speed and temperature can be
altered, but their values will not be remembered by the instrument at its
next start-up.
The timer and temperature function may be shut off during manual operation
by holding down their respective symbol keys. The blower may be altered, but
not turned off.
At any time during the operation of the unit, you can revert to standby mode
by pressing the off button (0) on the front panel. Should the instrument
behave differently than described above, please notify your dealer or call
Endecotts. Failure to pass the power on tests are indicative of either an
indicator or the function itself not operating correctly.
- 25-
Maintenance
Chapter 3 cont/…
Fuses
The FBD has four fuses accessible on the back of the instrument. All the
fuses used are Fast Fuses (Quick-Blow). There are two possible instrument
configurations being used and the position of the fuses are different on
each. Both configurations, Type A and Type B, are shown below.
Fuse Type Colour Purpose
230V 110V
A blue general 15A 25A
B green blower 8A 10A
C yellow heater 10A 20A
D red Pulse flow 2A 2A
View of the Back of Fluid Bed Dryer Digital
Fuse type A and C are finger-turn
Fuse type B and C are screwdriver
- 26-
Specification
Model: Fluid Bed Dryer Digital Voltage: 110v or
230v Frequency: 50Hz or 60Hz
Phase: 1
Power Consumption: 3.2kW Class: E 1 (earthed)
Dimensions:
260 x 340 x 495 mm (H x W x D) Weight: 19 kg
- 27-
General Advice
Endecotts’ shakers are fully tested and factory checked before shipping to
customers. No parts require lubrication or resetting unless disturbed.
The sieve shaker has been constructed and factory tested to ensure correct
operation when connected to the specified electricity supply indicated on
the machines rating plate.
Use of unapproved spares or any alteration to the machine will invalidate
all warranties and compliance with European
Directives for ‘CE’
Marking.
- 28-
Endecotts Ltd does not accept any responsibility if the
operating instructions contained in this manual
are not strictly followed.
ZMFBD -MAN1 ISSUE 09/12
________________________________________________________________________________________________________________
Endecotts Limited, Lombard Road, London SW19 3TZ England
Tel: + 44 (0) 20 8542 8121 Fax: + 44 (0) 20 8543 6629
E-mail: sales@endecotts.com web site http://www.endecotts.com
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