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Still Controller


jerrysun2014

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Specification for Still Controller.

General notes

The still will be operated with 3x 5.5kwultra low density heating elements. Each of these heating elements will be supplied from a separate 415volt 3ph 50 Hertz supply from the distribution board.

The distribution board will be positioned away from the unit to ensure that is outside of any alcohol vapours. The distribution board will be fitted with 30amp MCB trips and a 60amp ground circuit breaker.

Cables will be run to the still control board in conduit and access ports should be provided to enable the attachment of the conduit.

The controller should be both water proof (IP56 or equal) and explosion proof in accordance with NEMA Class 1 Group B.

Temperature measurements and display.

Temperature measurements shall be made by thermocouples to the following points on the still

  1. Still head ( top of column)
  2. Still head (entry to lyne arm for pot still operations)
  3. Cooling water supply temperature
  4. Temperature outlet of condenser
  5. Temperature outlet of reflux coil

The temperatures recorded shall be displayed on the control bow in degrees Celsius. The length of the thermocouple cables shall be a minimum of ***meters.

Control box General requirements

The still control box shall be complete with the following functions

  1. Enabling key lock which prevent the unit from being actuated.
  2. Emergency stop button. This function should disable power supply to all heating coils. It should also have an auxillary shutdown to enable any water pumps to be stopped.
  3. Individual heating coil start buttons for each of the coils. These should be individually wired so that only one coil can be turned on at a time.
  4. Warning lights shall be wired to show each coil is turned on and operating.
  5. Over temperature alarm for each heating coil shall be wired to prevent running the coil without liquid cover. The temperature should be set to 105 degrees Celsius but should be adjustable by the operator. The over temperature should have both flashing and audible alarms.

Still control functions

Supplier is requested to propose a method of controlling the still operation. The control functions should be designed to minimise manual control and adjustment during operation.

Two methods are requested

Semi-automatic control

In Semi-automatic mode it is desired that once a still controlling set point has been set that the control system manages the heat supply to the still with the goal of maintaining the set point.

Fully automatic control

In this mode the set point temperature at the top of either the lyne arm or at the top of the column should be modulated in accordance with the general increase in temperature seen to maintain ethanol production over time.

(The temperature of production gradually increases from 78C-98C as the ethanol is driven of and as the percentage ethanol in the tank is depleted)

This changing set point over time could be accomplished by a learning function where set points are recorded from a manual operation. The controller can then be programed with this data. This should work if all still runs are kept constant in volume. This is called a pre-set program.

The controller should have the capability to store up to 5 pre-set programs. The pre-set programs can be numbered. The program should be selectable from the controller and the number of the selected program should be indicated on the control box.

Once the still has completed a set run an alarm should be sounded and a warning light should flash.

Control box mounting

The control box should be wall mountable. Screw access holes shall be provided in the back of the box sealed to prevent ingress of water and vapour and in accordance with the specified standards.

who can do,please contact me. Email: zjjerrysun2011@hotmail.com

regarding the controller please ask the maker to create a full specification so that we can ensure it meets the requirements we set.this should cover both functional and technical aspects and will ensure that we have a common understanding and that any final doubts are resolved before we confirm the build.

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