An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor during normal operations and selectively opens and closes certain of the valves when the temperature falls below a predetermined threshold to enter a safe mode that avoids freezing of the valves during operation. If an exhaust valve is open when safe mode is entered, the corresponding inlet valve is closed, both of the exhaust valves are closed, and the other inlet valve if opened. If an exhaust valve is not open, both inlet valves are opened and both exhaust valves are closed.

A method is provided for detecting and quantifying obstructions in a gas network under pressure or vacuum. The gas network may be provided with a sensor(s) capable of recording the status of a source(s), consumers, or consumer areas. The method includes: a possible start-up phase; a baseline or zero phase; and an operational phase. The operational phase includes: reading out the first group and second group of sensors; re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors; determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase; generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction if an obstruction is detected.

A method is provided for detecting and quantifying obstructions in a gas network under pressure or vacuum. The gas network may be provided with a sensor(s) capable of recording the status of a source(s), consumers, or consumer areas. The method includes: a possible start-up phase; a baseline or zero phase; and an operational phase. The operational phase includes: reading out the first group and second group of sensors; re-estimating, determining or calculating the physical model or mathematical relationship on the basis of the read measurements from the sensors; determining or calculating of the existence of an obstruction in the system based on the difference and/or its derivatives between the parameters of the physical model or mathematical relationship as determined during the baseline or zero phase and the operational phase; generating an alarm and/or generating a degree of obstruction and/or generating the corresponding obstruction if an obstruction is detected.

This invention relates to a four-state adjustable air path structure. An air source is connected to an air storage tank and a first two-position three-way solenoid valve via a check valve. The first two-position three-way solenoid valve is connected to a second two-position three-way solenoid valve and a vent hole. The second two-position three-way solenoid is connected to a third two-position three-way solenoid valve and a port of a throttle valve. Another port of the throttle valve is connected to the third two-position three-way solenoid valve. The third two-position three-way solenoid valve is connected to an air tank. The present four-state adjustable air path structure simplifies processing and maintenance of a mechanical structure. Intellectual control of an operating speed can also be achieved. The present invention has advantages such as structural simplicity, low manufacturing costs, safe and reliable operation, long service life, and suitability for long-distance transmission.

A compressed air supply unit for operating a pneumatic unit by means of a compressed air flow, in particular of an air suspension unit of a vehicle, comprises an air dryer arrangement in a main pneumatic line that pneumatically links a compressed air feed line from an air compressor and a compressed air connection to the pneumatic unit. A valve arrangement is pneumatically connected to the main pneumatic line for controlling the compressed air flow. The air dryer arrangement has a drying container having a container outer wall. A partition along a length of the drying container divides an internal space delimited by the container outer wall into first and second chambers delimited by the partition and the container outer wall. The partition adjoins the container outer wall along the length of the drying container, and the first and second chambers are adjacent to one another along that length.

A compressed-air treatment system and operating method are disclosed. The compressed-air treatment system has a first valve unit configured to charge a control line for a compressor with pressure and a pressure regulator valve unit configured to release pressure from a feed line, A control port of the pressure regulator valve unit is connectable to a second valve unit. A regeneration line which has a check valve for regeneration and which is utilized for a regeneration of a dryer cartridge is connected directly to the control line. During a filling operation the compressed-air treatment system is configured to release leakage air of the regeneration check valve via the first valve unit to surroundings. The filling operation is an operating state in which the compressor is activated to perform a supply of compressed air to a vehicle compressed-air system.

A compressed-air treatment system and operating method are disclosed. The compressed-air treatment system has a first valve unit configured to charge a control line for a compressor with pressure and a pressure regulator valve unit configured to release pressure from a feed line, A control port of the pressure regulator valve unit is connectable to a second valve unit. A regeneration line which has a check valve for regeneration and which is utilized for a regeneration of a dryer cartridge is connected directly to the control line. During a filling operation the compressed-air treatment system is configured to release leakage air of the regeneration check valve via the first valve unit to surroundings. The filling operation is an operating state in which the compressor is activated to perform a supply of compressed air to a vehicle compressed-air system.

The present disclosure provides a compressed air processing system of which the operation of supplying compressed air and the regeneration operation can be efficiently controlled by an electronic control unit. In particular, the present disclosure is characterized in that the pressure of a regeneration sequence valve installed in a regeneration line is increased over a set pressure by controlling a valve, which is electronically controlled, to switch, so the opening time of the regeneration line is delayed in comparison to the opening time of an unloader valve, whereby regeneration efficiency is improved.

A compressed air supply device for an air suspension system of a motor vehicle comprising a motor-driven compressor, a dryer, a discharge path from the dryer to the outside, and an adjustment device for changing a flow cross section of the discharge path is provided in the discharge path.

Method for venting a pneumatic system of a vehicle, pneumatic system and vehicle Method for venting a pneumatic system (1) of a vehicle, the pneumatic system (1) comprising an air compressor (4), a pneumatic circuit (2), an air pressure management system (6) in communication with the air compressor (4) and the pneumatic circuit (2), and a control unit, the method comprising: —while pressure in the pneumatic circuit (1) is less than a cut-out pressure, supplying the pneumatic circuit (2) with compressed air from the air compressor (4) operated at an operating speed through the air pressure management system (6), —once pressure in the pneumatic circuit (2) reaches the cut-out pressure, lowering pressure in the pneumatic circuit (2) to a target pressure, the air compressor (4) being operated at at least one deflating speed lower than the operating speed, the deflating speed being non null, —after pressure in the pneumatic circuit (2) has reached the cut-out pressure, releasing compressed air in the air pressure management system (6) to the outside environment.