Apparatus capable of operating both as nitrogen generator and carbon dioxide absorber, particularly for the preservation under controlled atmosphere of products, such as fruit and vegetable products

An apparatus capable of operating both as nitrogen generator and carbon dioxide absorber, particularly for preserving under controlled atmosphere fruit and vegetable products and the like, comprising a generator, including a reactor receiving therein a mixture of air and fuel gas, such as propane or methane gas, means for feeding said mixture to said reactor, the reactor comprising a burner space for combustion, so that gaseous combustion products exit from the reactor and comprise nitrogen and carbon dioxide, two absorbers, each suitable to retain carbon dioxide, a condenser downstream of the reactor and upstream of the absorbers having the gaseous combustion products passing therethrough, so that steam in said combustion products is condensed and claimed as water in a liquid state, means for water cooling said condenser and burner space, means for feeding the gaseous combustion products comprising nitrogen and carbon dioxide from the condenser to both absorbers, means for feeding gas exiting from either absorber to a product-containing cell or storage room, or alternatively to an exhaust or outlet, means for connecting said cell or storage room, with either absorber for supply of the cell or storage room atmosphere, means for feeding scavenging air to the absorbers, means by which when an absorber is operating to retain carbon dioxide of the gaseous volume from the burner or cell, the other absorber having scavenging air passing therethrough and vice-versa, and means for operating the apparatus only as either nitrogen generator or absorber of carbon dioxide of the cell or storage room atmosphere, said reactor comprising two parts which substantially form two opposite walls of said burner space, each of said walls comprising two opposed sheets spaced from each other and having laterally spaced indentations along a dimension thereof, the indentations being disposed on both sheets confronting each other and in contact along the full dimension defining a seal therebetween to define separate channel paths having rods inserted therein for flow of cooling water therethrough along predetermined, substantially coiled paths to maintain said walls at substantially uniform temperature distribution and to facilitate substantially smooth combustion with substantially complete elimination of flashback and a substantial reduction in the risk of failure because of uneven temperature districution, said apparatus further comprising a tube conveying the gaseous volume from either absorber, which has retained carbon dioxide, a three-way valve connected to said tube and having two tubular sections extending therefrom and respectively connected to a tube leading to an outlet, the last-mentioned tube, and a tube leading to the cell having a non-return check valve provided in the tubular section between said three-way valve and tube leading to the stack, for allowing the passage of said gaseous volume only in the direction from said three-way valve to said tube leading to the stack.