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Thread: Dedicated oil heating element v water heating element

  1. #1
    Join Date
    Jun 2008
    Location
    Queanbeyan
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    21

    Dedicated oil heating element v water heating element

    During processing I heat my oil in 400L batches using a 3.8kW water heating element . This has worked for several years but recently either the elements or the thermostats have been failing.
    I understand oil doesn't remove heat quickly enough from a water heating element and this causes them to fail.
    Whereas the water for which it is designed removes heat more quickly.

    I would like to hear from other users who use water elements satisfactorily or if anyone knows of a good source of a dedicated oil heater. Scintex sell one for $800-$1299 but the water heater are about $50
    With thanks. Tim

  2. #2
    Join Date
    Aug 2015
    Location
    Canberra
    Posts
    8

    Re: Dedicated oil heating element v water heating element

    Hi tbooth,
    Sounds like your thermostat may have failed. The standard HW thermostats are unreliable at the lowest settings.
    What temperature do you run at?
    I use a 2.4kw element, an ebay digital thermostat and a stirrer to keep the oil moving to prevent the element from overheating. I have set my thermostat to 25 DegC.
    Using a 4.8kw element may be working with at rather higher surface temperature, could fail.
    An oil circulating pump or a stirrer is ok
    My processor will handle 250ltr + and has been in service for about eight years wit no problems
    Hope the helps.
    Peter

  3. #3
    Join Date
    Jun 2008
    Location
    Queanbeyan
    Posts
    21

    Re: Dedicated oil heating element v water heating element

    Quote Originally Posted by Bigboy View Post
    Hi tbooth,
    Sounds like your thermostat may have failed. The standard HW thermostats are unreliable at the lowest settings.
    What temperature do you run at?
    I use a 2.4kw element, an ebay digital thermostat and a stirrer to keep the oil moving to prevent the element from overheating. I have set my thermostat to 25 DegC.
    Using a 4.8kw element may be working with at rather higher surface temperature, could fail.
    An oil circulating pump or a stirrer is ok
    My processor will handle 250ltr + and has been in service for about eight years wit no problems
    Hope the helps.
    Peter
    Thank you Peter.
    25 seems a low temp for processing I have been using about 45-50degrees.
    I use a 400L vessel for processing and the element is situated at about the 260L level so the top half of the mix heats well and therefore I need to stir at intervals throughout the 4-5 hours it takes to get to that temp to ensure that the whole 400L is raised to temp.
    With the heater running there is a strong convection current that I have always assumed would keep the element 'cooled' so didn't stir constantly whilst processing.
    I have been using a 3.8kW element and would be reluctant to go to 2.4 as it would take much longer to get to temp. However if I only tried to get to 25 that would make a big difference. Is there a reason you process at 25 and not hotter?
    After your message however I think I will continue with water heating elements for cost reasons among other things and set the thermostat at a lower temp.
    Thanks Tim

  4. #4
    Join Date
    Sep 2005
    Location
    WA
    Posts
    4,324

    Re: Dedicated oil heating element v water heating element

    Quote Originally Posted by tbooth View Post
    Thank you Peter.
    25 seems a low temp for processing I have been using about 45-50degrees.
    I use a 400L vessel for processing and the element is situated at about the 260L level so the top half of the mix heats well and therefore I need to stir at intervals throughout the 4-5 hours it takes to get to that temp to ensure that the whole 400L is raised to temp.
    With the heater running there is a strong convection current that I have always assumed would keep the element 'cooled' so didn't stir constantly whilst processing.
    I have been using a 3.8kW element and would be reluctant to go to 2.4 as it would take much longer to get to temp. However if I only tried to get to 25 that would make a big difference. Is there a reason you process at 25 and not hotter?
    After your message however I think I will continue with water heating elements for cost reasons among other things and set the thermostat at a lower temp.
    Thanks Tim
    If you are concerned with the water heater element overheating, you could use a "simmerstat" (ie stove element temperature control) to reduce the duty cycle of the element before the thermostat operates. This is in effect reducing the power usage of the element and the temperature of the element surface.
    Again, it will increase the time to reach the desired processing temperature.
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