Foundry Sand Heaters
Del Sol’s extensive no bake and cold box experience and coupled with our desire to build simple yet effective machines have been applied to foundry sand heaters. Trying to maintain the utmost in simplicity and retain superior quality and operation, we have developed our version of the foundry sand heater.
- SH-45 (300 # / Minute @ 35°F ΔT)
- SH-90 (600 # / Minute @ 35°F ΔT)
- SH-150 (1000 # / Minute @ 35°F ΔT)
- SH-225 (1500 # / Minute @ 35°F ΔT)
We build a heavy steel fabrication, coupled with easily serviceable element bundles, controlled by a modern yet simple control package. Why? So that your machine heats sand every day, and if it breaks, your maintenance team can fix it with their skillset. We have done our best to deliver a machine that runs and doesn’t cause issues, breakdowns, or lost production time. We have included as standard what is optional on competitive units, and have designed the machine with the service technician in mind. We addressed the unforgiving foundry environment with a machine that can handle it for the long run.
We also provided for a little distance. Often, with other designs, you are trying to jam equipment into the “angle of the dangle”, under a silo, over a mixer, etcetera and still try to maintain the decent angle of repose. Del Sol’s version provides for horizontal length without chewing up a bunch of vertical heights. In doing so, we are able to unclutter your under silo condition, get the mixer a little farther away from the wall or a silo, and clean the area up a bit. The nice thing with this design, is that if you need some distance, but not all of the elements, we can simply install the elements required to heat to your specifications and cap the rest. We get the distance you need at the power level you require.
We use a butterfly valve for the sand inlet. Most other manufacturers do this as well, but they generally adjust the sand flow rate by trying to screw threaded rods into the actuator to adjust the stops. This results in a lot of trial and error in order to confirm the sand flow rate, and the sand usually has to be run completely through the heater for calibration. With the Del Sol design, we have put a replaceable fixed orifice sand metering plate below the butterfly valve. This allows the machine to be calibrated with the same sand flow rate/orifice chart that is used for calibration on most mixers in the foundry. We have also included a removable plate directly below the inlet valve and metering plate to allow a real measurement of calibration in a really easy way.
Clean and dry compressed air is a commodity often in short supply in a foundry. Even when there is ample air flow, there are often issues with moisture or other contaminants in the air supply. For this reason, we include a regenerative scroll blower with all heaters as standard. This is an optional upgrade on other units available in the market. We also include the necessary controls, inlet filters, pressure relief valves, bleed-off valves for the blower, and also ship it pre-mounted to the heater with the interconnecting plumbing included. This design method provides for a relatively small blower motor running to fluidize the heater rather than having to utilize valuable CFM/HP from your compressor system.
The fluidization membrane is fully accessible by removing a hinged cover plate from the bottom of the heater. The heater ships as standard with a canvas/screen composite membrane, but our design has been configured to easily allow upgrades to fully metallic or porous plastic membranes for high temperature or specialized media applications.
Most sand heaters available on the market utilize basic bent elements that are inserted from the bottom of the heater and tightened from the top of the heater in compression fittings. The elements are then all wired individually from the top of the heater. In the event of a failed element, the technician must do a lot of troubleshooting to determine which element has failed. To do this, they must remove the top cap of the heater, remove all sand from inside the heater, remove the door, remove the bottom cap, remove the fluidization membrane, concentrate really hard to make sure they have the right element identified from both top and bottom, crawl back up top of the heater, unwire the element, loosen the compression fittings, crawl to the bottom and pull out the bad element, stick the new element back up into the heater from the bottom, fight with the compression fittings, finally get irritated and go get a second technician to lift the element from the bottom while the first technician crawls back to the top and tightens the compression fittings back up, rewires the element, puts the fluid membrane back in, put the bottom cap back on, puts the door back on, puts the top cap back on, refills the heater with sand, and restarts the unit. As bad as that run-on sentence is, the job to simply replace a single bad element on a typical heater is worse by a hundredfold.
For the Del Sol Sand Heater, we have chosen a small bundle style heating element which installs from the side of the unit and bolts onto a standard 6” diameter 150# pipe flange welded to the unit. The process to replace an element bundle on Del Sol’s Heater is:
- Determine which element is failed (optional operating lights make this even easier)
- Shut down the heater disconnect, lock out tag out.
- Disconnect the feed wires from the enclosure on the element cap on the bad element
- Pull (8) ¾” bolts and pull the element out by hand
- Stick the new element in and insert the (8) ¾” bolts
- Reconnect the feed wires in the enclosure on the element cap
- Turn the heater back on
That’s it. There is no need to remove the top cap, remove the door, drain sand, remove the fluid membrane, fight with compression fittings, etc. It is a one-technician job to change an element bundle on the Del Sol Sand Heater.
We have utilized a standard ANSI Flange on the discharge of the heater to allow a simple, easy connection to downstream equipment with standard off-the-shelf pipe fittings.
ELECTRICAL CONTROL SYSTEM
The controls for Del Sol’s are simple and robust. They feature a high quality flanged disconnect enclosure, programmable logic controller, SCR controls for even distribution of power to the heating elements, integral temperature controller, and an over temperature controller.
We do fluidize with air and that air needs to go somewhere. In most cases, the vents can go back to the top of the silo feeding the heater. However, with silica exposure limits, your desire to maintain a clean shop, and to provide for the lowest fines going into your sand system, we do recommend going with dust collection from the supplied dust takeoff vents.