Documentation:Thermo Scientific Econotherm Drying Oven
What are the drying ovens for?
The drying ovens are typically used to dry soil to determine soil moisture. The suitability of non-soil materials must be confirmed by checking the equipment manual for each oven.
Description of equipment
The Econotherm 1025 (6530) is a gravity convection oven. Air is drawn into the oven’s chamber at the bottom of the unit and is heated as it passes over the electric heating coil. Heating the air causes its density to change, resulting in the warmer air rising up through the diffuser panel located on the bottom of the inner chamber. A limited amount of air is vented out the top of the oven while the remaining air recirculates within the chamber. Gravity convection ovens are ideal where forced air circulation cannot be tolerated and for situations demanding gentle curing or long-term sample storage under closely controlled conditions. Gravity convection ovens are ideal for drying powders, soil samples, paper goods, semiconductors and cosmetics.
General Safety Guidelines
This SOP applies to anyone who intends to use the drying ovens. Any questions regarding their use are to be directed to the APBI Teaching and Research Support Technician (1st) or the Operations Manager (2nd). Anyone who intends to use the drying ovens is to review this SOP.
The following guidelines outline hazards associated with the use of the drying oven:
DO NOT LOAD OVEN with tissue, material, or liquids that:
· Are easily flammable, combustible or explosive
· Release poisonous vapor/dust that forms combustible mixtures when exposed to air
· Exhibit exothermic reactions, are pyrotechnical substances (eg: flash powder)
· Create a humid atmosphere
· release dust
· exhibit exothermic reactions
· are pyrotechnical substances
DO NOT exceed the specified hurdle load to ensure sufficient air circulation and uniform heating.
· VWR
o Maximum load: 25kg/55lbs
o Do not use more than 70% of the maximum surface area of the work space.
o The bottom floor of the chamber must be kept free and clear of objects and never used as a shelf.
o Bulky objects in the work space that dissipate heat may impair heat distribution
· ECONOTHERM
o At least one inch (2.5cm) should be left between objects placed on the shelves.
o The bottom floor of the chamber must be kept free and clear of objects and never used as a shelf.
o At no time should solid shelves be substituted for the shelves that are provided. Additional shelves and shelf supports are available from Thermo.
DO NOT place sealed containers in chamber. Sealed containers filled with materials do not provide room for expansion or evaporation, may develop vapor pressure as temperature increases.
DO NOT place plastic materials that melts at extreme temperatures as this poses a fire hazard. (If plastics are placed in the oven, do not leave it unattended)
DO NOT store containers filled with acidic or caustic solutions within the chambers, as vapors from these materials will attack the chamber interior and electrical components.
DO NOT use these ovens for food service or the preparation of meals.
Required PPE
· Always wear heat resistant gloves when loading / unloading into a hot oven.
· Lab coats and closed toed shoes are required in the laboratory.
· Use appropriate PPE for specified cleaning solutions where required
WARNING: All internal surfaces become hot. Wear appropriate gloves and
other PPE when removing items from the oven or loading into a hot oven.
Standard Operating Protocol
Before You Begin:
- DO NOT cover the shelves with foil or reduce their open surface area by more than 75%.
- DO NOT overfill oven.
- DO check that the oven is free of debris before use and clean up spills immediately.
- DO NOT place inappropriate items in this oven for drying. Consult Section 7.04 (safety) of the operations manual to confirm what is appropriate.
- DO keep the exhaust vent shutter cap on the top of the oven open at all times.
Note: if oven is running at the maximum rated temperature, it may be necessary to turn the cap to a more closed position to retain heat.
To Operate:
1. Fill in pink oven use form with a dry erase marker to ensure other users know when the oven will be finished operation.
2. Check that door seals properly. Notify Technician if seal is damaged.
3. Press the ON/OFF switch to the ON position.
4. Rotate the Temperature Control knob to achieve the desired temperature (4 for 105 °C). Note: Temperature has stabilized when the lamp turns on and off at regular intervals..
5. Load samples into the oven ensuring that:
- At least one (1) inch (2.5cm) of space is between objects placed on the shelves.
- The bottom floor of the chamber is kept free and clear - it is not a shelf.
6. To shut down, press the ON/OFF power switch to the OFF position.
7. Clean up any spills that occurred.
8. Leave temperature controls at 4 (105 °C), the standard temperature for drying soil.
Note: When the lamp above the Temperature Control is illuminated, an electric current is being applied to the heater. It is normal for this lamp to cycle on and off during operation of the oven.
9. Unplug AC power plug to power down the oven completely.
WARNING: All internal surfaces become hot. Wear appropriate gloves and
other PPE when removing items from the oven or loading into a hot oven.