Abstract:
An electrostatic sprayer operable at high flow rates and low pressures particularly suitable for spray drying. The sprayer includes an elongated body having a downstream spray nozzle assembly through which electrically charged liquid is directed via a central feed tube within the nozzle body and atomizing air is supplied via an annular passage about the liquid feed tube. In one embodiment, the nozzle assembly is an external mix cluster head spray nozzle assembly having a plurality of circumferentially spaced metallic spray tips. In another embodiment, the spray nozzle is an internal mix nozzle assembly having a spray tip with an internal mixing chamber for atomizing liquid prior to discharge.
Abstract:
A switch mode power supply circuit with high voltage output, an electrostatic spray apparatus and agricultural plant protection apparatus using the same are provided. The switch mode power supply circuit is electrically connected in series with at least a pre-stage power converter and a post-stage power converter. In order to simplify the control, the switch of the pre-stage power converter is omitted, only one switch of the post-stage power converter is adopted to perform synchronous control. Since the multiple sets of power conversion circuits in the previous stage are connected in series, the turn ratio of the transformer in the power converter in the subsequent stage can be reduced. Therefore, the transformer can be miniaturized and the power supply circuit would be more suitable for agricultural plant protection machine and electrostatic spray apparatus.
Abstract:
Exemplary coating methods and coating systems, e.g., for coating the component surface of a component with a coating agent by means of an atomizer in a coating system, for example to paint a body part of a motor vehicle with paint, are disclosed. An exemplary method comprises moving the atomizer over the component surface of the component to be coated, or moving the component in the spray jet, thereby applying the coating agent to the component surface by means of the atomizer. The atomizer may be operated with at least one electrical and/or kinematic operating variable comprising a certain voltage for the electrostatic charging of the coating agent and/or a certain rotational speed of a rotating spray element of the atomizer. In one example, the electrical and/or kinematic operating variable of the atomizer may be dynamically varied during the movement of the atomizer.
Abstract:
An integrated liquidjet system capable of stripping, prepping and coating a part includes a cell defining an enclosure, a jig for holding the part inside the cell, an ultrasonic nozzle having an ultrasonic transducer for generating a pulsed liquidjet, a coating particle source for supplying coating particles to the nozzle, a pressurized liquid source for supplying the nozzle with a pressurized liquid to enable the nozzle to generate the pulsed liquidjet to sequentially strip, prep and coat the part, a high-voltage electrode and a ground electrode inside the nozzle for charging the coating particles, and a human-machine interface external to the cell for receiving user commands and for controlling the pulsed liquidjet exiting from the nozzle in response to the user commands.
Abstract:
A method of stripping, prepping and coating a surface comprises first stripping the exiting coating from a surface, using continuous or pulsed fluid jet, followed by prepping the surface by the same fluid jet. The method also provides entraining particles into a fluid stream, if desired to generate a particle-entrained fluid stream that is directed at the surface to be stripped and prepped. The particles act as abrasive particles for prepping the surface to a prescribed surface roughness required for subsequent application of a coating to the surface. The method then entails coating the surface by electrically charging particles having the same chemical composition as the particles used to prep the surface. Finally, a charged-particle-entrained fluid stream is directed at high speed at the charged surface to coat the surface. The particles form both mechanical and electronic bonds with the surface.
Abstract:
A high voltage controller configured to drive a high voltage generator. The high voltage controller includes a voltage select input and a current select input, an actual voltage input and an actual current input. First circuitry is configured to generate an alternating current (AC) drive signal. Second circuitry configured to generate a direct current (DC) drive signal. Closed loop control circuitry is configured to adjust the DC drive signal based on at least one of the voltage select and current select inputs and at least one of the actual voltage and actual current inputs. The first circuitry may include a push-pull circuit. The second circuitry may include a pulse width modulation (PWM) controller. A high voltage generator may be coupled to the AC and DC drive signals. The high voltage generator may include a high voltage transformer having a pair of primary windings and center tap. The AC drive signal may be coupled to the primary windings and the DC drive signal may be coupled to the center tap.
Abstract:
An electrostatic coating plant coats components with a coating agent that is electrically charged by high voltage device. A first operating variable of a high voltage device may be determined and compared to a limit value. A safety measure may be initiated if the comparison between the first operating variable and the limit value indicates a disturbance in the electrostatic coating plant. The limit value may be flexibly adjusted depending on the operation mode.
Abstract:
The invention relates to an electrostatic projector (P1) comprising: an insulation body (1); a rotatably movable projection member (2); rotational driving means (7); high-voltage power supply means (26); conducting elements (2.1, 6, 22, 23); a detection device (40) for evaluating the rotation speed of the projection member (2), the detection device (40) including at least one target (41, 42) on a rotary component and a sensor (43) adapted for detecting the or each target. The projector (P1) further includes at least one insulating wall (50) that defines a housing (51) surrounding the sensor (43) for insulating the entire sensor (43) from the conducting elements (2.1, 6, 22, 23). The sensor (43) is separated from the space (V) scanned by the rotating target (41, 42) by an essentially axial detection distance (H).
Abstract:
A process and an apparatus for coating glass by means of a method using at least one or more liquid raw materials which react essentially on at least a portion of the glass substrate forming a coating on it. At least part of the liquid raw materials is atomized to droplets with one or more two-fluid atomizer and at least a fraction of the gas used in the one or more two-fluid atomizers is electrically charged such that at least a fraction of the droplets become electrically charged during or after the atomization. According to the invention the droplets are formed into a separately created electric field.
Abstract:
A high voltage controller configured to drive a high voltage generator. The high voltage controller includes a voltage select input and a current select input, an actual voltage input and an actual current input. First circuitry is configured to generate an alternating current (AC) drive signal. Second circuitry configured to generate a direct current (DC) drive signal. Closed loop control circuitry is configured to adjust the DC drive signal based on at least one of the voltage select and current select inputs and at least one of the actual voltage and actual current inputs. The first circuitry may include a push-pull circuit. The second circuitry may include a pulse width modulation (PWM) controller. A high voltage generator may be coupled to the AC and DC drive signals. The high voltage generator may include a high voltage transformer having a pair of primary windings and center tap. The AC drive signal may be coupled to the primary windings and the DC drive signal may be coupled to the center tap.