WINTER OPERATIONS OF A BFK CONCRETE RECLAIMER

WINTER OPERATIONS OF A BFK CONCRETE RECLAIMER
Reclaimers obviously rely on water to accomplish their tasks. It is used both in the
reclaimer itself, for washing, and is also stored in the slurry handling system.
Obviously, when temperatures drop below freezing, things must be done to keep the
water flowing, as well as to keep the machine from freezing up and becoming
inoperable, or causing equipment damage.
This write-up will give you some options, ideas, tips and tricks to keep your BFK
Reclaimer in operation year round.
I. Reclaimer
The first area to look at is within the Reclaimer itself. There are 4 main areas of water
concentration within a BFK reclaimer.
1. Infeed Hopper
The infeed hopper, where the drivers wash-out, receives all of the wash water from
the mixer trucks. In addition, there are spray nozzles to help keep material flowing
and the hopper clean.
2. Plumbing
When the system is installed, care should be taken to ensure all hoses used are
installed to allow for drainage. If the proper care is taken, the system will drain back
through the pump, if located in a settling pond.
3. Rotary Screen
There are 2 spray nozzles spraying water onto the rotary screen, to effectively wash
and separate the cement from the aggregates.
4. Sand Screw
The lower half of the sand screw always stores water. Because of this, BFK offers the
optional Sand Screw Heater, to keep this stored water from freezing. Alternately,
users can drain the sand screw during freezing weather.
Obviously, heating and/or draining help keep internal locations from freezing, however,
the biggest problem is that of ice build-up, especially in areas where there is water
spray, such as in the infeed hopper, and inside the shroud housing the rotary screen.
In some locales, even where freeze conditions occur, outside temperatures are warm
enough where simply checking for, and then removal of, ice build-up allows the
Reclaimer to operate without any major problems. These are the type of installations
where the optional Sand Screw Heater is highly recommended.
In other locations, winter temperatures are simply too cold for too long to make this a
viable operation year-round. Options follow as to what to do in these locales.
Winter Operations of a BFK Concrete Reclaimer.doc
Feb. 2014
II. Settling Ponds
The main purpose of the settling ponds is to collect the spent cement slurry, allow the
cement enough time to settle out, and then to reuse this water which (after the cement
has settled out) can be pumped back to the Reclaimer for further use on incoming waste
concrete mix.
Settling ponds have 2 requirements for proper operation of the Reclaimer:
1. liquid water
2. drive-in access by a front-end loader for clean-out
Being “ponds”, they obviously freeze.
III. Possible Solutions
There are 4 main approaches that customers have taken to deal with Reclaimer
operations in the winter.
1. Shut-down
Some customers find it is easier and more cost-effective to shut-down the Reclaimer
for the winter months. Being that their business also drops off substantially in the
winter months, the amount of waste concrete they need to deal with is greatly
minimized as well.
This is an effective option in areas where winter is not too long. A Sand Screw Heater
is recommended here, and the operator may have to remove ice build-up when
needed to keep the Reclaimer operating as long as possible.
2. Deal with the Ice on the Reclaimer, stir or heat the ponds
Handle the ice build-up on the Reclaimer as needed, as described in section I above
(knock off any ice build-up, make sure all plumbing is installed to allow drain-out thru
the pump, etc.). A sand screw heater is recommended in this case.
To keep the water in the pits liquid, we have seen a couple of unique approaches.
One way is to install a second pump in the settling ponds. This is simply a recirculating
pump, to keep the water flowing around the ponds. This will minimize the thickness
of the top ice-layer, and also keep liquid water below the ice, where the Reclaimer
pump is operating. When it comes time to clean spent cement out of the pit, the ice
layer is not substantial, and the weight of the front-end loader simply breaks thru the
ice to allow for clean-out.
A second idea is to run heat tubes in the floors or walls of the settling ponds while the
concrete is being poured. You can then circulate warm water thru the pipes during
winter months to keep them open. The heat source could be as simple as a small
outdoor wood-burning furnace, which are readily available in most northern locales
(becoming very popular with homeowners). One customer in Wisconsin states that he
simply stockpiles his wood waste year round (pallets, shipping containers, etc.), and
that is enough fuel to feed the wood burner in the winter and keep the ponds from
freezing up!
Winter Operations of a BFK Concrete Reclaimer.doc
Feb. 2014
3. Heat the Reclaimer, stir or heat the ponds
Other customers have actually built a small building or structure around just the
Reclaimer itself. A small kerosene, waste oil or other-type heater can then keep the
internal air above freezing, and keep the reclaimer in operation.
The ponds can then be handled as explained in the last section (recirculating pump or
heater tubes).
A Sand Screw Heater is not necessary in this case, as the Reclaimer will be inside of a
heated structure. You may wish to consider it as a back-up, however, in case the
regular heater fails. Some ice build-up may occur within the infeed hopper, depending
on the design of the structure, and the ability of the heater.
4. Put up a building
More recently, we have seen an increase in the number of buildings that are going up
to house the entire Reclaimer system, including the settling ponds.
Obviously, there are both higher up-front costs (price of the building), as well as
operating expenses (cost to heat the building).
However, more and more operators, especially those located in or near built-up areas
and family communities, are becoming more sensitive to the public concerns of having
open water ponds on your property. This is both a safety and liability concern.
Obviously, it is much easier to keep kids locked out away from the ponds when you
have a building.
IV. Conclusion
In the end, it will be up to the individual operator as to the route they decide on. You
will have to weigh the cost to keep it running vs. the cost to provide the solution.
BFK Technologies Inc.
1113 Park Ave.
Kiel WI 53042
(920) 894-1113
888-235-8235
www.BFKTECH.com
Winter Operations of a BFK Concrete Reclaimer.doc
Feb. 2014