A control system for an operable system such as a flow control system or temperature control system. The system operates in a control loop to regularly update a model with respect at least one optimizable input variable based on the detected variables. The model provides prediction of use of the input variables in all possible operation points or paths of the system variables which achieve an output setpoint. In some example embodiments, the control loop is performed during initial setup and subsequent operation of the one or more operable elements in the operable system. The control system is self-learning in that at least some of the initial and subsequent parameters of the system are determined automatically during runtime.

A control system for an operable system such as a flow control system or temperature control system. The system operates in a control loop to regularly update a model with respect at least one optimizable input variable based on the detected variables. The model provides prediction of use of the input variables in all possible operation points or paths of the system variables which achieve an output setpoint. In some example embodiments, the control loop is performed during initial setup and subsequent operation of the one or more operable elements in the operable system. The control system is self-learning in that at least some of the initial and subsequent parameters of the system are determined automatically during runtime.

A fan, in particular axial fan and preferably backward-curved radial fan, having an impeller equipped with blades, an electric motor for rotating the impeller and a device for determining the airflow when the impeller is rotating. The device for determining the airflow includes a volume flow measuring wheel arranged in the air flow, which is arranged upstream of the impeller on the inflow side. The air volume flow is calculated or derived from the rotational speed of the volume flow measuring wheel.

A fan, in particular axial fan and preferably backward-curved radial fan, having an impeller equipped with blades, an electric motor for rotating the impeller and a device for determining the airflow when the impeller is rotating. The device for determining the airflow includes a volume flow measuring wheel arranged in the air flow, which is arranged upstream of the impeller on the inflow side. The air volume flow is calculated or derived from the rotational speed of the volume flow measuring wheel.

A vacuum exhaust apparatus capable of accurately and rapidly adjusting the pressure in an exhaust chamber and a vacuum pump used therein are provided. A vacuum pump includes a rotor that rotates to exhaust an exhaust chamber and a casing having an inlet port. A valve is located between the inlet port of the vacuum pump and an outlet port of the exhaust chamber. A controller performs control such that the pressure in the exhaust chamber matches a target value. The controller adjusts the opening degree of the valve when the absolute value of the difference between the pressure in the exhaust chamber and the target value is greater than a predetermined value, and adjusts the rotational speed of the rotor of the vacuum pump when the absolute value of the difference between the pressure in the exhaust chamber and the target value is less than the predetermined value.

Operation of a multistage compression system comprising at least one centrifugal compressor having a dry gas seal with opposed seal faces, for compressing a gas feed having a variable flow rate is improved by operating the or at least one centrifugal compressor in a low power mode where the opposed faces of the dry gas seal are not in contact during periods when gas flow through the centrifugal compressor(s) is not sufficient for normal operation. Such operation not only reduces damage to the dry gas seals and hence improves reliability, but also reduces the overall power requirement of the overall compression system.

The present invention relates to a fruit or vegetable shaped fan for dispersing airborne eye irritants that are released during cutting fruits or vegetables. The fan includes a base that is wedge-shaped, an air inflow collimator that is fruit or vegetable shaped having an open front end, an internal frame that is configured to provide minimal abatement to airflow through the air inflow collimator, a motor mount that secures a motor, a fan blade that attaches to the motor, and a grill that attaches to the open front end of the air inflow collimator. The fan is configured to disperse airborne eye irritants away from a user's eyes. Airborne eye irritants are released when certain fruits and vegetables are chopped or otherwise cut. Such fruits and vegetables that can release airborne eye irritants when cut include onions, peppers, and certain other fruits and vegetables.

The present invention relates to a fruit or vegetable shaped fan for dispersing airborne eye irritants that are released during cutting fruits or vegetables. The fan includes a base that is wedge-shaped, an air inflow collimator that is fruit or vegetable shaped having an open front end, an internal frame that is configured to provide minimal abatement to airflow through the air inflow collimator, a motor mount that secures a motor, a fan blade that attaches to the motor, and a grill that attaches to the open front end of the air inflow collimator. The fan is configured to disperse airborne eye irritants away from a user's eyes. Airborne eye irritants are released when certain fruits and vegetables are chopped or otherwise cut. Such fruits and vegetables that can release airborne eye irritants when cut include onions, peppers, and certain other fruits and vegetables.

A vacuum pump comprises: a rotor rotatable in a predetermined rotation direction; and a case housing the rotor; and a fixed component arranged facing an inner wall of the case. A clearance is formed between the inner wall of the case and the fixed component, and a groove allowing communication between the clearance and an exhaust path in the case is formed at either the inner wall of the case or the fixed component.

A centrifugal compressor includes: an impeller provided in a housing; a throttling portion provided in front of the impeller in the housing; an actuator rod connected to an actuator and including a plate portion including a plane at its end; and a connecting portion connected to the throttling portion and including a pair of projections facing each other across the plate portion in an axial direction of the actuator rod.