Rotary-Bell Spray

Paint coating machine for large-scale production environments

The ultra-high speed rotary bell coater is a paint coater for large-scale production environments. Also known as the “paint clock” or “bell applicator”, it combines a high-performance air turbine with superior transmission efficiency compared to a spray gun.

The uniformity of the spray mode and the low compressed air consumption make it more economical and suitable for large-volume applications. It is an air-bearing rotary atomizer for bell jars.

Our rotating bell applicator consists of the following main components:

• Valve module:
  Includes channels for paint, solvent, and compressed air, as well as valves that control its flow into the system for paint delivery, cleaning and solvent purging, as well as managing compressed air to valves, turbines, and air hoods.
• Bell cup
  It is a conical disc that is fixed to the turbine shaft (robot arm). The paint is poured into the center of the rear portion of the disk to form a film at the bottom. The centrifugal force then pulls the paint toward the edge of the cup where it breaks into atomized droplets.
• Turbine
  It is a high speed air motor that can rotate the clock cup from 10,000 rpm to 70,000 rpm depending on the diameter of the cup, the desired atomization and the physical properties of the coating.
• Ring with small pinholes such as a shaped air hood or a shaped air ring
  Used to vent air from the front of the nebulizer outside the diameter of the bell cup to control the size of the spray pattern produced. Typically, as more air is pushed through the shroud, the atomized coating will be shaped into a smaller pattern.
• Electrostatic system
  It can be internal or external depending on whether the charge is applied directly or indirectly to the coating particles. In an internal or direct process, the applicator is supplied with a high voltage charge (typically between 20,000 and 90,000 volts DC) that has the effect of charging the coating prior to atomization. On the other hand, in an external or indirect method, a high voltage is supplied to a series of 4-8 front-facing electrodes placed in a circular array around the bell cup. This has the effect of ionizing the surrounding air, which charges the paint droplets as it flows through the area (due to free ions).

According to the standard model, Rihting will design the air bearing according to the customer’s specifications, in addition to the minimum paint loss, and design a very short washing time and excellent efficiency, achieving world-class coating quality and first-class film thickness uniformity.