uv lamps is preferably about 3 u2033 to 1 u2032 they can line up in any pattern in the preferred embodiment of this invention there are 98 uv lamp tubes 15 in two rows along the circuitous sterilizing chamber 10 these lamps are fixed on both front and rear side of the chamber 10 increasing the number of uv lamps can increase the sterilizing power of the apparatus the length and roundabouts of the chamber 10 can also be increased to get more space to install uv lamps fig3 illustrates an apparatus with a substitution of uv lamps of fig1 in this preferred embodiment of the invention the uv lamp tubes 15 here are preferably double end tube shape non ozone germicidal lamps lining up in any pattern the incoming side of the lamp sockets shall be covered with airflow guiding plates not shown to reduce airflow resistance these kinds of uv lamps have the characteristics of higher uv power output and lower cost in order to perform maintenance there are five maintenance doors with anti ultraviolet sealing on the edges in this embodiment fig4 depicts another preferred embodiment of this invention this embodiment is with a different orientation to meet different installation needs the inlet 1 is preferably positioned on the other side of the air outlet 11 and the uv lamp fixtures 4 only installed on one side of the housing 8 fig5 depicts an apparatus for sterilizing water in large volume by radiation of ultraviolet rays according to a preferred embodiment of this invention water.