Abstract: In a powder coating system wherein the powder is introduced via a feed conduit from the feed point to a mixing chamber, a pressure gradient oriented against the chamber is produced along the feed conduit by acceleration of a gas jet in the mixing chamber, and pressure recovery is obtained by retarding the powder-gas stream, in order to feed the powder-gas stream through a conveying line to a coating unit. For increasing the quantity of powder dispensed per unit time to the powder coating system, the pressure drop in the powder-gas stream along the conveying line is at least in part compensated for by raising the pressure at the feed point.

Abstract: In order to measure the temperature of a body (3) extensively independently of interference radiation (.theta..sub.U1), a sensor (1) is provided wherein the radiation (.theta..sub.3) of the body (3) is chopped by means of a chopper (5) between the sensor (1) and the body (3). Since extraneous radiation originates predominantly from losses at the sensor (1) as well as from frictional heat of the chopper (5) in case a mechanical chopper (5) is provided, the housing temperature of the sensor (1) is detected for correction purposes on the side of the chopper (5) facing the sensor (1) by means of an additional sensor (13). Around and in the zone of the travel path of the mechanical chopper (5), by means of a third sensor (15), the ambient temperature of the chopper is detected, again for correction purposes.

Abstract: A fast axial flow gas laser apparatus comprising an at least essentially closed loop defining a flow path for a laser gas, an arrangement for exciting gas flowing in the loop of the apparatus to cause the gas to lase, and a regenerative compressor for flowing gas through the closed loop along the flow path. The compressor is capable of operating with a pressure ratio sufficient to flow the gas along at least a portion of the loop at a speed at least half the speed of sound in the gas with inlet pressures of only a small fraction of an atmosphere. The uniform discharge pressure of the compressor results in a uniform laser discharge or output. A positive pressure fluid pressure seal prevents lubricant at a bearing support for the impeller shaft of the compressor from moving to the impeller and possibly contaminating the laser gas being compressed thereby and also prevents surrounding air from contaminating the laser gas.

Abstract: A method and apparatus for measuring a temperature of a body extensively independently of an interference radiation. The apparatus comprising a sensor wherein a radiation of the body is chopped or interrupted by a chopper disposed between the sensor and a body. In order to sense extraneous radiation which originates predominately from losses at the sensor as well as from frictional heat of the chopper, the housing temperature of the sensor is detected for correction purposes on a side of the chopper facing the sensor by an additional sensor. Around and in the zone of the travel path of the chopper, an additional sensor is provided for sensing an ambient temperature of the chopper.

Abstract: A method of stabilizing an operation of a continuous axial gas laser including at least one gas flow tube system comprising at least one excitation tube, and a gas flow circulation arrangement connected to the gas flow tube system to generate a gas flow therethrough. The gas flow circulation system generates a timed pulsating gas flow and an output pressure signal having a predetermined frequency spectrum. The flow tube system has a pressure-versus-frequency damping transmission characteristic between an input from the gas flow circulation arrangement and the excitation tube, with the damping varying with a frequency of the pressure pulsations applied to the input. The continuous axial gas laser is stabilized by shifting the predetermined frequency spectrum of the pulsating gas flow generated by the gas circulation arrangement with respect to frequency and the damping transmission characteristic to minimize the pressure pulsations to the excitation tube from the gas flow circulation arrangement.

Abstract: A fast axial flow gas laser apparatus comprising an at least essentially closed loop defining a flow path for a laser gas, an arrangement for exciting gas flowing in the loop of the apparatus to cause the gas to lase, and a regenerative compressor for flowing gas through the closed loop along the flow path. The compressor is capable of operating with a pressure ratio sufficient to flow the gas along at least a portion of the loop at a speed at least half the speed of sound in the gas with inlet pressures of only a small fraction of an atmosphere. The uniform discharge pressure of the compressor results in a uniform laser discharge or output. A positive pressure fluid pressure seal prevents lubricant at a bearing support for the impeller shaft of the compressor from moving to the impeller and possibly contaminating the laser gas being compressed thereby and also prevents surrounding air from contaminating the laser gas.

Abstract: To prevent a formation of aerodynamic dead zones in a coating arrangement for powder coating, such as, for example, weld seams, a surface of a supporting member is provided with a constantly increasing radius of curvature between an outlet orifice for a spray jet and an exhaust orifice, starting with the former. A feed conduit is fashioned so that a laminar flow of the coating medium does not experience a change in an arithmetic sign of its path of curvature in the orifice zone and along a subsequent surface. For a constant acceleration of the spray jet, a constant reduction of the flow cross section is provided for the spraying medium between the outlet and the exhaust conduit.

Abstract: An axial flow gas transport laser comprising an excitation tube through which gas flows along an axis of the tube, an inlet arrangement to feed gas towards the excitation tube and an outlet arrangement to discharge gas from the excitation tube. At least one of the inlet and outlet arrangements comprises a circumferential opening arrangement evenly distributed along the periphery of the excitation tube, substantially in a cross-section plane of the tube. A gas flow channel arrangement to the opening arrangement is directed at least substantially in the direction of the excitation tube axis and into the excitation tube at the opening arrangement for preventing wide-areal turbulances of the gas flowing in the excitation tube.

Abstract: A method of lasing gas, a fast axial flow gas laser and an excitation tube for a fast axial flow gas laser are disclosed. Increased thermal energy per mass flow unit of the gas flowing through the excitation tube of the laser can be applied to the gas by controlling at least along a part of the tube the extent of a central area of higher speed gas flow which is surrounded by a circumferential low speed, speed dependent boundary layer by steadily varying the cross-section area of the excitation tube at least along the part thereof to compensate for the circumferential low speed boundary layer.

Abstract: An axial flow gas transport laser comprising an excitation tube through which gas flows along an axis of the tube, an inlet arrangement to feed gas towards the excitation tube and an outlet arrangement to discharge gas from the excitation tube. At least one of the inlet and outlet arrangements comprises a circumferential opening arrangements evenly distributed along the periphery of the excitation tube, substantially in a cross-section plane of the tube. A gas flow channel arrangement to the opening arrangement is directed at least substantially in the direction of the excitation tube axis and into the excitation tube at the opening arrangement for preventing wide-areal turbulances of the gas flowing in the excitation tube.