Valves & Flow Control
Made in Britain
TELEPHONE
Handling Adhesive Products
Handling
Adhesive
with
Rotary Valves
Products with
Rotary Valves
Adhesion is the tendency of dissimilar particles or surfaces to
cling to one another.
prevent the product from plugging.
dhesive products tend to
than drop through style rotary valves
(Note: Under positive pneumatic
come from the food and
because the rotor conveys directly in
conveying conditions two rotor vanes
chemical industries. Fatty,
to the conveying line. This is especially
should be sealing at all times to
dhesion
is
the
tendency
of
dissimilar
particles
or
oily products with high
pertinent if the connection pipes have
prevent excess leakage air). Product
surfaces
cling
to one
another. Adhesive
products
moisture
can tobe
stic
y as
been
designed to efficiently purge
contact surfaces should be polished or
tendstarches,
to come fromwax
the food
are milk powders,
- and chemical
theindustries.
rotor pockets. Valves designed
have a non-stick coating applied and
Fatty,
oily
products
with
high
moisture
(+20%)
can
gelatine powder, lactose, soap noodles,
to provide a smooth ull flow o
avoid narrow or multi-vane rotors,
be sticky as are milk powders, starches,conveying
wax - gelatineair through the convey line
maltodextrine powders.
even with polished surfaces and nonpowder, lactose, soap noodles, maltodextrine powders.
pipe connection with minimal pressure
stick coatings because highly adhesive
Adhesive products will stick to the
drop will also aid product
discharge,
A larger
valve running slowly with less rotor vanes and scalloped rotor pockets will
Adhesive products will stick to the valve internals causing the running
products can still adhere to them.
valve
internals
causing
the
running
preventing
the
possibility
of
line
also provide a wider rotor pocket that will aid product discharge and prevent the
clearance to block, which can lead to the valve seizing up. The product can plug in
product
from plugging.
clearance
block,
which causing
can lead
blockage
/ lodgement
and thus
product(Note: Under positive pneumatic conveying conditions
the bottomto
of the
rotor pockets
reduced throughput,
line blockage
and
Do not specify replaceable bladed
two rotorhygiene
vanes should
to later
theproduct
valve degradation.
seizing up.
The
product
is be sealing at all times to prevent excess leakage air).
Highly
adhesive
products can contamination,
be very poor flowing vital where
rotors
for sticky
because
Product
contact
surfaces
should
be polished
or have aproducts
non-stick coating
applied
can
plug
in the
bottom
of the
rotorthe desired throughput
a factor. difficult to
which
makes
the sizing
of a valve
to achieve
product
will
stick
to
the
ledge
at the
and avoid narrow or multi-vane rotors, even with polished surfaces and non-stick
pockets
causing
reduced
calculate.The
solution
is to makethroughput,
sure you choose the correct valve. Blowing Seal
bottom
ofcan
the
the route of the
coatings because
highly adhesive
products
stillblade
adhere in
to them.
line
blockage
androtary
latervalves
product
A larger
valve
with reduced
capacity
(Blow
through) style
with scalloped rotor pockets
are usually
better
rotor pocket and do not use closed
degradation.
rotor
will provide a wide
suited to adhesive products than drop through style rotary
valvespockets
because the
rotors
product
will hold
upproduct
on the
Do not specify replaceable bladed
rotors–for
sticky products
because
will
rotor conveys directly in to the conveying line.
shallow poc et con guration. his
stick to the ledge at the bottomclosed
of the blade
in the
route
of the
rotor
and
rotor
end
disc
and
it pocket
can also
Highly adhesive products can be very
is proven to aid discharge
of sticky
do not use closed rotors – product
hold upthe
on the
closed rotor
discdisc
and it
getwill
behind
closed
rotorend
end
This fl
isowing
especially
pertinent
if the
pipes have been
designedand
to also prevents
poor
which
ma
esconnection
the si ing
products
thebehind
product
can
also
get
the closedand
rotor end
discup
anduntil
build up
until
the valve
seizes.
build
the
valve
seizes.
the rotor pockets.
Valves designed to provide
a smooth
flow
of efficiently
a valvepurge
to achieve
the desired
plugging
in full
the
bottom of the rotor
of conveying air
through
thecalculate.
convey line pipe connectionpocket,
with minimal
throughput
diffi
cult to
as pressure
there is noOn
narrow
bottom
drop through
rotary valves,On
rotordrop
pocketthrough
purge ports
can be drilled
to aid
rotary
valves,
rotor
drop will also aid product discharge, preventing the possibility of line blockage
section for product topocket
adhere
to. and finally a product sample can be useful to determine the
discharge
pocket
purge
ports
can
be
drilled
to aid
/ lodgement and thus product contamination, vital where hygiene is a factor.
The solution is to make sure you
level of adhesion and product flow prior to the supplier quoting.
A larger valve with reduced capacity rotor pockets will provide a wide shallow
poc et discharge and nally a product
choose
the correct valve. lowing eal
A larger valve running slowly with less
pocket configuration. This is proven to aid discharge of sticky products and also
sample can be useful to determine the
Email: [email protected] Tel: +44 (0) 1249 651138
(Blow
through)
style
rotary
valves
prevents
the product
plugging
in the
bottom with
of the rotorrotor
pocket,vanes
as there and
is no scalloped rotor pockets
level o adhesion and product flow prior
scalloped
rotor
pockets
are to
usually
will also provide a wider rotor pocket
Web: www.rotaval.co.uk
narrow bottom
section
for product
adhere to.
to the supplier quoting.
better suited to adhesive products
that will aid product discharge and
A
A
Issue 23 PECM
115