NEEDLE VALVE Russian patent published in 2019 - IPC B05B7/04 B05B7/12 

FIELD: machine building.

SUBSTANCE: group of inventions relates to a needle valve for controlling liquid flow of a coating agent in a coating apparatus, in particular for controlling the flow of a two-component mixture of two components of a coating agent, for example, a basic lacquer and a curing agent. Needle valve for controlling liquid flow of coating agent (H, SL) in a coating installation, in particular for controlling the flow of a two-component mixture of two components (H, SL) of a coating agent, in particular a two-component varnish from a main lacquer (SL) and curing agent (H), has inlet (1, 2) for a coating agent for supplying a coating agent, valve seat (7) and a displaceable valve needle (4) having a needle rod and needle head (5). In the closed position of valve needle (4), needle head (5) closes valve seat (7). In the open position of valve needle (4), needle head (5) releases valve seat (7). Needle valve also has a flexible membrane, which annularly and tightly surrounds valve needle (4) upstream of needle head (5). Pressure of the covering agent at inlet (1, 2) for the covering agent, starting from a certain opening pressure, squeezes valve needle (4) through the membrane from the closed position to the open position. Opening pressure of the covering agent at inlet (1, 2) for the covering agent is at least 8 bar and largest 35 bar. In the coating installation having at least one needle valve is preferably located in one of the following structural components of the coating installation: a rotary atomizer, a two-component mixer for mixing both components of the coating agent, a two-component shut-off valve for locking or releasing the two-component mixture or a shut-off valve for the hardener and/or main varnish. Dosing system for dosing the coating agent has a pipeline for a coating agent for passing a coating agent, a dosing pump in the pipeline for a coating device, for dosing the coating, a bypass pipeline for bypassing the dosing pump. Bypass pipeline upstream of the metering pump branches off from the pipeline for the covering agent and downstream the dosing pump flows into the pipeline for the covering agent again. Dosing system also has a bypass valve, which is located in the bypass pipeline. Bypass valve represents a membrane valve, namely a needle valve with a membrane.

EFFECT: technical result of group of inventions is higher reliability of needle valve, possibility of uncontrolled pressure release into system, which reduces environmental pollution.

15 cl, 15 dwg