Operating method for a conveying device with an eccentric screw pump for conveying viscous construction materials

A method of operating a conveying device with an eccentric screw pump for conveying a construction material, the method comprising:

• sensing a pressure of the construction material at an outlet of the eccentric screw pump when the eccentric screw pump is running to provide the construction material to a dispensing device;
• based on the pressure exceeding an upper limit value, automatically switching off the eccentric screw pump;
• sensing a characteristic variable of the eccentric screw pump;
• comparing the characteristic variable with at least one of:
• a first comparison variable that represents operation of the dispensing device in an open position, or
• a second comparison variable that represents operation of the dispensing device in a closed position:
• switching off the eccentric screw pump based on detecting operation of the dispensing device in the closed position;
• based on the switching off of the eccentric screw pump, monitoring a pressure prevailing at the outlet of the eccentric screw pump and restarting the operation of the eccentric screw pump in response to detecting at least one of:
• the pressure prevailing at the outlet of the eccentric screw pump falling by a first pressure difference within a first time interval due to opening of the dispensing device or the dispensing device being in the open position, or
• the pressure prevailing at the outlet of the eccentric screw pump falling to a lower limit value or by a second pressure difference with the dispensing device in the closed position, the second pressure difference being greater than the first pressure difference.

A conveying device comprising:

• an eccentric screw pump;
• and
• a controller configured to:
• receive a pressure of a construction material at an outlet of the eccentric screw pump when the eccentric screw pump is running to provide the construction material to a dispensing device;
• based on the pressure exceeding an upper limit value, automatically switch off the eccentric screw pump;
• detect a characteristic variable of the eccentric screw pump;
• compare the characteristic variable with at least one of:
• a first comparison variable that represents operation of the dispensing device in an open position, or
• a second comparison variable that represents operation of the dispensing device in a closed position:
• switch off the eccentric screw pump based on detecting operation of the dispensing device in the closed position;
• based on the switch off of the eccentric screw pump, monitoring a pressure prevailing at the outlet of the eccentric screw pump and restarting the operation of the eccentric screw pump in response to detecting at least one of:
• the pressure prevailing at the outlet of the eccentric screw pump falling by a first pressure difference within a first time interval due to opening of the dispensing device or the dispensing device being in the open position, or
• the pressure prevailing at the outlet of the eccentric screw pump falling to a lower limit value or by a second pressure difference with the dispensing device in the closed position, the second pressure difference being greater than the first pressure difference.