Spray Dryer

By Projects Lab


The spray dryer uses compressed air and high temperatures to atomize liquid slurries and create dried particulate product.


Fully Functional


MEB 3520

Standard Operating Procedure

Spray Dryer Standard Operating Procedure


Prior to operating the Bowen Spray Dryer familiarize yourself with the plumbing, display
gauges, control panel, pump, pump drive, and blower.
The Bowen Engineering Spray Dryer is a pilot scale device commonly used for drying
thermally sensitive materials. In the Senior Lab, it has been used for drying a variety of
solutions including soap, salt and beer.
Verify that any solution pumped through the system will not clog the lines or the spray
Check with lab manager before preparing a new solution.


Health & Safety Warnings

  • Safety glasses must be worn when operating this equipment.
  • The manual gas control valve must be closed after each run.
  • Do not remove the drive shaft guard.
  • To prevent overheating, the gas burner will not light until the blower is powered
  • Use caution when opening the spray dryer door during operation as liquid may
    escape the drying chamber.
  • Caution – exterior surfaces may be hot!
  • Rotating equipment hazard: Use caution when in close proximity to the pump.



  1. Mix feed solution in tank(s) located behind the spray dryer. Verify that the feed
    tank valves remain closed until you are ready to run.
  2. Set (open) valves on feed tanks to feed stock solution to pump as desired.
  3. Using a wrench, remove the pump drain plug until feed stock/water flows out of
    pump housing, then replace the plug, tighten it finger tight and then tighten it ¼
    turn with a wrench.
  4. If feedstock does not flow out of the pump valve, contact the lab manager.
  5. Open the main gas pipe valve ½ turn so that the valve headpiece is in line with
    the pipe. The valve is located on the rear of the spray dryer.
  6. Turn on the Omega HH509R thermometer located on the front of the spray
  7. Open the main air supply valve located on the right side of the dryer ½ – 1 turn.
  8. Set the air pressure regulation to 10 PSI. The air pressure regulator is located on
    the lower front panel. You may adjust the air pressure as required as you fine-
    tune your operating parameters. The airflow rate may be adjusted by adjusting
    the air pressure regulator.
  9. Turn on the main power switch located on the upper left of the control panel.
  10. Verify that the Baldor Drive Controller (VS1MD) displays 0.00.
  11. Verify that the FWR and STP/FLT indicator lights are on and that the PROG and
    RUN lights are off.
  12.  If the PROG light is on do not proceed, contact the lab manager.
  13. Note that when adjusting the speed setting on the VS1MD, you must push firmly
    and hold the increment / decrement arrow buttons in order for the setting to
  14.  Before pushing start on the pump control, firmly press and hold the down arrow
    on the VS1MD, if the numbers on the display start to decrease hold the down
    arrow until the display reads 0.00. Once the display reads 0.00 when the down
    arrow is held down, proceed to the next step.


Check the Chamber:

  1. Open the chamber door.
    The chamber light switch is located on the right side of the control panel.
    Verify there are no obstructions in the chamber.
    If the chamber requires cleaning, use the hose located behind the spray dryer to
    clean the system. Cleaning supplies are located in the stock room.
    It is your responsibility to clean the spray dryer after each use.
  2. Verify that the spray nozzle is connected to the air and feed lines.
  3. Close the chamber door.
  4. Latch both chamber door fasteners to secure the door.

Set pump speed:

  1. The VSIMD pump controller retains the last speed setting so it is important to
    zero the pump speed setting before turning on the pump for the first time.
  2. Once the pump has been running it’s okay to stop and start it without resetting
    the zero, start value.
  3. Press and hold the decrement button on the VS1MD, the display will decrement
    if the last setpoint was greater than zero. continue to hold the decrement button
    until the display reads zero.
  4. Press Start, the run LED will lite.
  5. Press the increment button, the numerical display will increment. The pump will
    begin to rotate at a setting of about 15.
  6.  A setting of 20 corresponds to a flow of approximately 2 GPH.
  7.  To stop the pump press Stop/Reset, the STP/FLT LED will lite.
  8.  Do not press REV. The control defaults to the forward (FWD) mode.
  9.  The flow rate is displayed on the small rotameter. The pump controller (VFD)
    display is in frequency not flowrate.
  10.  The pump speed may be adjusted at any time during operation my firmly holding
    down the up / down arrows on the VS1MD.
  11.  The maximum pump speed is 60.00 . Note that the pump drive will not rotate if
    the set point is below approximately 3.50.

Stopping the pump:

To stop the pump, push the red STOP / RESET button located on the upper right of the

Restarting the pump:

  1. Pushing the red START button on the VS1MD will immediately start the pump at the last
    set point.
  2. To display the pump speed set point currently in the controller memory, press the
    up/down arrow button before pressing the start button.
  3. If you wish to start the pump at a speed other than the last set point use the up/down
    button to set the desired set point prior to pushing the start button.

Start the blower:

  1. Push the black start button on the fan control panel; you should immediately hear the
    blower power up.

Setting the burner temperature:

  1. The Partlow burner temperature adjustment is located on the rear of the spray dryer, to
    the right of the main gas valve. The temperature may be adjusted at any time during


Lighting the burner:

  • Note – the blower must be running in order to ignite the burner.
    1. Verify that the main gas valve is open.
    2. Push the black start button (burner control) located directly above the fan start/stop
      control. Verify that the burner is lit via the observation port on the burner assembly.

Sample Collection:

  1. Sample material is collected in the bell jar located at the bottom right of the spray dryer.
  2. Additional bell jars and spray nozzles are located in the workbench in front of the spray



  1. Stop the pump
  2. Turn off the burner
  3. Turn off the blower
  4. Turn off the main power switch
  5. Turn off the Omega HH509R
  6. Close the main gas valve.
  7. Close the feed valves (ball valves) that control the feed flow from the feed tanks
    to the pump.
  8. Drain & rinse the feed tanks as needed.
  9. Rinse the spray dryer chamber.
  10. Clean the work area.
  11. If you plan on leaving feed solution in the tanks overnight, it must be labeled