APPARATUS FOR PRODUCING RIGID POLYURETHANE FOAM BY FROTHING METHOD

摘要

An apparatus for producing a rigid polyurethane foam by the frothing method in which the supply of a compressed or liquefied inert gas as a blowing agent can be interlocked with the working of a foaming machine. The apparatus for producing a rigid polyurethane foam by the frothing method includes a blowing-agent feeder which supplies an inert gas as a blowing agent at a constant rate and a foaming means which mixes the inert gas with a polyol composition to form a foamed polyol composition and then mixes the foamed polyol composition with a polyisocyanate ingredient to discharge a rigid polyurethane foam. The blowing-agent feeder has: a pressure-reducing valve with which the pressure of the inert gas is reduced and regulated; and a needle valve with which the flow rate of the inert gas is regulated. The foaming means has a cylinder for compression by which the polyol composition is compressed and supplied. A regulator which regulates the supply of the inert gas to the foaming means has been disposed between the foaming means and the blowing-agent feeder. The regulator has been connected to a controller which senses the working of the cylinder for compression to control the regulator.