Results 1 to 5 of 5
  1. #1
    Junior Member
    Join Date
    Mar 2014
    Louisville, KY

    PID vs normal roaster?

    Hello, I'm considering buying an electric roaster. I've found one that has a 2 lb capacity with PID for roughly the same price as another that holds 5 lbs, but does not have PID. Is PID that great? Does it allow for more precise roasting?

  2. #2
    Senior Member
    Join Date
    Oct 2013
    Milwaukee, WI
    The PID can take control of the roast, but in my world, I'd rather learn how to roast and do the controlling myself. If you want a roaster that you can set and forget, or have inexperienced people operating the machine, the a PID might be something to consider.

    The question is, what will the PID be controlling? Only heat? In that case you'll still have to control airflow, which makes it less desirable since you'll still have to attend the roast.

  3. #3
    Senior Member
    Join Date
    Jun 2014
    Minneapolis, MN
    The short answer is no. Most temperature controllers are PID, but when installed in coffee roasters, most are set for on/off control only. This means you might have a PID controller, but it's used as a high limit controller only.

    Beyond that, I'd need to know which roasters you are comparing.

  4. #4
    Join Date
    Jul 2014
    It depends on how you roast. When comparing gas vs electric, just like a stove top, gas has the potential for more "control-ability" in that it can turn on and off quicker than an electric element. There are faster reacting electric elements, but they can be brittle and less robust. That said, for control-ability on the gas, you will need a burner with high turndown ratio and a modulating valve on the gas train. The modulating valve can be adjusted manually (as per Peter's comments) or via a PLC.
    For control on the PLC, an effective "profile roasting" system does not need to utilize a PID control. Rather the PLC control can be considered a "step" control; that is when the coffee temperature reaches various temperature milestones, the burner is adjusted to levels for that particular roast profile recipe. This creates a profile roast control that repeatable and follows time temperature curves quite accurately. The airflow and drum speed is kept constant.
    A more sophisticated control is "curve following". This is a PID control that looks at the error between the actual bean temperature and the constantly moving set temperature as it moves along the curve. For smaller roasters, it still only modulates the burner and the airflow and drum speeds are kept constant. There are cost effective options available with this control, but the benefits over the "step" control are small and depend on your own perceptions on quality.
    On larger recirculating roasters, PID control can be used on the burner output, the fan speed, and the drum pressure. As discussed in other posts, roasting coffee on most drum roasters is primarily done through convection. Therefore, adjusting the air temperature entering the drum as well as the volume of air impacts the heat applied to the coffee. However, making adjustments on more than one variable at the same time can get complicated very quickly. Consequently, it is best to limit the adjusting to the burner output (to affect the inlet air temperature) and keep the airflow constant...or at specific settings throughout the roast.
    Last edited by ellatas; 08-03-2015 at 07:52 PM.

  5. #5
    Junior Member
    Join Date
    Feb 2020
    Any PID system is fairly easy in setup and programming. The tuning is where the magic happens and it is the difference between an incredible system and a shitty one.

    Pid works like this, it consists of 3 factors, proportional, integral and derivative controls. Proportional is the difference between the setpoint and the current value (error) multiplied by a factor (tuning).

    Integral is the history of the error, this builds up if even a small error exists. This removes the steady state error.

    The derivative is the change of the error over time, and tuning this prevents over- or undershooting.
    A friend of mine is using this PID controller. PID vs normal roaster?-enda.jpg
    Famaga supplies industrial equipment and spare parts for companies from all over the world



Remove Ads

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Similar Threads

  1. Replies: 8
    Last Post: 10-25-2014, 09:30 AM
  2. is my C.O.G normal ??
    By DukeCrab in forum Coffee Shops, Espresso Bars & Cafes
    Replies: 12
    Last Post: 01-05-2012, 01:44 AM
  3. is it normal to have some coffee grounds in the espresso
    By htc8p in forum Coffee and Espresso Machines
    Replies: 3
    Last Post: 05-09-2008, 10:04 AM
  4. Faema Family pump noise - normal?
    By ry in forum Coffee and Espresso Machines
    Replies: 0
    Last Post: 10-29-2006, 10:06 AM
  5. Is this normal for the first month of opening?
    By Anajoeri in forum Coffee Shops, Espresso Bars & Cafes
    Replies: 2
    Last Post: 01-26-2006, 07:12 AM

Search tags for this page

coffee roaster pid

Click on a term to search for related topics.

Tags for this Thread