Method and device for controlling the production of an extract using a solid-liquid extraction process

A device for controlling production of an extract by means of solid-liquid extraction using an extraction container, wherein:

• the extraction container has an inner region that, in a top region, possesses at least one supply connection for supplying a primary mixture and for supplying a secondary solvent, and, in a bottom region, a drainage connection for drainage of a mixture consisting of an extract and a raffinate,
• the drainage connection discharges into a drain line,
• the drain line has, viewed in a direction of flow and at a vertical distance from the drainage connection by a supply height relative to the direction of gravity, a control valve, a first mass flow meter for determining a first mass flow for the mixture, a separating device for separating the mixture into the extract and a raffinate with residual moisture, a dehumidification apparatus for dehumidifying the raffinate with residual moisture to a tolerable portion of extract in the raffinate with residual moisture by supplying mechanical energy to the raffinate with residual moisture, and a second mass flow meter for determining a second mass flow for an extract free from raffinate with residual moisture,
• the separating device and the dehumidification apparatus each comprise a vibration or shaking sieve, and
• a control apparatus is provided that, in terms of signaling, is connected to the control valve, the first mass flow meter, the second mass flow meter, and the vibration or shaking sieve, and that controls a degree of dehumidification by a feedback control intervention to the first mass flow and a supply of the mechanical energy based on the tolerable portion.

A device for producing an extract by means of solid-liquid extraction by means of an extraction container from which a circulation line branching off a drain line runs, wherein the extraction container:

• has a supply line for supplying a secondary solvent or a mixture consisting of a primary mixture and the secondary solvent, and the supply line enters via a foot area into the extraction container, penetrates the extraction container up to a headspace, and discharges at the headspace via an outlet, and
• has a drainage connection for discharging the secondary solvent or a mixture consisting of an extract and a raffinate, and the drainage connection leaves the foot area and transitions there into the drain line,
• the drain line has, viewed in a direction of flow and at a vertical distance from the drainage connection by a supply height in the direction of gravity;
• a control valve, a first mass flow meter for determining a first mass flow for the mixture, a separating device for separating the mixture into the extract and a raffinate with residual moisture, a dehumidification apparatus for dehumidifying the raffinate with residual moisture, and a second mass flow meter for determining a second mass flow for an extract free from raffinate with residual moisture, wherein the separating device and the dehumidification apparatus each comprise vibration or shaking sieve,
• from the drain line, upstream from the control valve:
• the circulating line branches at a branching point and joins the supply line at a joining point, and is flowed through from the branching point to the joining point, and
• inside the circulating line, relative to the branching point, first a pump for conveying the secondary solvent and then a dosing apparatus for dosing primary mixture into the secondary solvent are provided, and
• a control apparatus provided that, in terms of signaling, is connected to the control valve, the first mass flow meter, the second mass flow meter, and the vibration or shaking sieve, and that controls a degree of dehumidification by a feedback control intervention in the first mass flow and a supply of mechanical energy.