A method and apparatus for welding include initiating a pulse welding process includes initiating a welding arc by providing CC type welding power, maintaining the arc by providing CV type power. Then, pulse type welding power is provided. The method and system can be used to start short circuit, or other welding processes by providing short circuit power, or welding power of a given mode, instead of providing pulse power. Also, in one alternative, a method and system of initiating a pulse, short circuit, or given welding process includes initiating a welding arc by providing CC type welding power at least until a pseudo-equilibrium for the arc is established. Then, providing welding power in a pulse, short circuit, or the given mode.

Method and apparatus for welding

The invention relates to a desalination method and system that uses freeze crystallization technology that incorporates the use of compressed air energy as the source for freezing temperatures. When compressed air is released by a turbo expander, chilled air is produced as a by-product, wherein the chilled air is introduced into a crystallization chamber. Also injected into the chamber is a spray cloud of seawater droplets, which has been pre-chilled by heat exchange with the cold chamber walls, and which is then circulated and exposed to the chilled air in the chamber. The sizes of the droplets can vary, but are preferably predetermined, along with the relative temperatures, flows and speeds of the spray and chilled air, such that when the droplets are circulated within the chilled air, and settle at the bottom of the chamber, they are deposited at slightly above the eutectic temperature. This way, the ice/snow mass that forms at the bottom of the chamber will consist of frozen ice crystals, and a residue of salt water brine, which can runoff from the mass, either from the sides, or through any voids or channels that may form within the mass.

Desalination method and system using compressed air energy systems

An electric arc welder including a high speed switching power supply with a controller for creating high frequency current pulses through the gap between a workpiece and a welding wire advancing toward the workpiece, where the pulses and a background current defining a series of weld cycles. A wave shape generator defines the shape of the pulses and the background current including a controlled ramp up and/or ramp down in each of said cycles and a circuit to change the shapes of the pulses and/or background current in a repeating pattern in each of the weld cycles. The shape change in a cycle can be between first and second shapes or by a rhythmic AC modulation.

Electric arc welder using high frequency pulses

In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted This reduces the generation of spatters after an arc is created and until the arc is stabilized

Arc welding control method

A method and apparatus for controlling a welding-type power supply includes providing a current wave form having an arc current portion and a short circuit current portion. An arc state is entered by retracting a welding wire, and a short circuit state is entered by advancing the wire. The current enters the arc current portion prior to the creation of the arc and the current enters the short circuit current portion prior to the creation of the short, by coordinating the wave form with the wire retraction. This may be preformed on a wire having a diameter of 2.4 mm or more to a weld and applying a welding current of less than 100 amps, or of less than 35 amps. One current waveform during the arc state includes at least three segments, and the last segment is entered into prior to the short circuit state being entered, and is the same current magnitude as the current magnitude at the start of the short circuit state. Penetration and/or bead formation may be controlled by controlling the advancement of the wire into the weld pool. The balance may be user set.

Method and apparatus for controlling a welding system

In a consumable electrode type arc welding method, when short circuit shift welding is conducted at the start of an arc in the process of pulse arc welding and also when an inclinations of a rise or fall is decreased in the case of starting an arc in the process of pulse welding and also when an inclination of a short circuit current is increased, short circuit, which irregularly occurs at the start of an arc, can be released in a short period of time and the arc can be stabilized early. When the generation of a magnetic arc blow is suppressed, it becomes possible to form proper welding beads. Due to the foregoing, the efficiency of welding work can be enhanced.

Consumable electrode type pulse arc welding method

A power apparatus is used in an arc welding device to control a weld operation during a welding start time. An improved arc start performance is obtained in both a cooled condition of the welding wire tip end portion and a red heated condition thereof. A feed quantity of the consumption electrode during the weld start time is changed depending on whether the welding wire tip end portion is cooled or red heated from a prior arc welding operation.

Arc welding power apparatus having plural selectable electrode feed quantity settings

Comprising means for feeding a welding wire, means for feeding a pulse current between the welding wire and base metal, and means for controlling this pulse current feeding means, the control means controls the pulse current feeding means so as to flare up the welding wire upon arc starting, and then controls the pulse current feeding means until the pulse current becomes lower in frequency than the pulse frequency of the main welding current.

Pulse welding equipment and its control method

An arc welding system includes a welding power source unit for producing welding power for fusing welding wire to weld a workpiece. An internal resistor is incorporated in the welding power source unit. A relay is inserted between the internal resistor and the welding power source unit for switching a connection therebetween according to the operating condition of the arc welding system. The relay connects the internal resistor and the welding power source unit only while the arc welding system is performing a welding operation.

Welding power source

A superimposed voltage waveform with a predetermined cycle and amplitude is superimposed on a commanded voltage waveform for a second predetermined time after a first predetermined time elapses within an arcing period in which an arc is produced. The predetermined cycle of the superimposed voltage waveform is shorter than a short-circuit cycle and longer than a control cycle of a welding power supply unit. This suppresses a growth of a weld droplet by being pushed up toward a consumable electrode and suppresses an excessive growth of the droplet over an entire range from a low current range, characterized by frequent short-circuits, to a medium to high current range where short-circuits are less frequent. The droplet is also smoothly transferred to the weld pool in addition to preventing excessive droplet growth. This reduces the generation of spatter, giving a flatter bead appearance.

Toshinori Hongu

Papers

Consumable electrode type pulse arc welding method

Arc welding power apparatus having plural selectable electrode feed quantity settings

Pulse welding equipment and its control method

Welding power source

Welding output control method and arc welding equipment