GB1149941A - Apparatus and method for prilling ammonium nitrate - Google Patents

Abstract

1,149,941. Granulating ammonium nitrate. ARMOUR AGRICULTURAL CHEMICAL CO. 29 April, 1966 [30 April, 1965], No. 18899/66. Heading B5A. [Also in Divisions B1 and C1] Ammonium nitrate is prilled by maintaining a body of liquid ammonium nitrate in a quiescent state over a plate provided with apertures so that streams of free-flowing liquid fall from the body of the liquid through an atmosphere of cooling gas, and impinging upon the free-flowing streams sonic vibrations at a frequency which causes the streams to break into droplets of substantially uniform size. In Fig. 1, liquid ammonium nitrate, preferably in the form of a 94-97% by weight aqueous solution, contained in head tank 22 controlled to give a head of 30 to 170 inches of water, is passed through line 23 and headers 24 into spray header assemblies 25. Here, a reservoir 27 of molten ammonium nitrate is maintained in a quiescent state, so that regular streams of liquid flow through the orifices in plate 29 into sound chamber 30, where sound waves from generator 32, via amplifier 33, speaker drivers 34, sound manifold lines 35 and tributary pipes 36 impinge upon the falling streams, breaking them up into regular sized droplets, as at 37, and these droplets fall through a countercurrent stream of cooling gas and are collected as regular sized prills at the base of the cooling tower. The sonic vibrations may have a frequency of 700 to 1250 c/s. Suitable types of orifice plate are described.