Tube to tube sheet welding for fabrication of vertical boiling reactor with reduced tube pitch

A shell-and-tube heat exchange reactor comprising:

• an inlet tube sheet having a plurality of first openings and located at an inlet end of the reactor;
• an outlet tube sheet having a plurality of second openings and located at an outlet end of the reactor;
• a plurality of elongated tubes located between the inlet tube sheet and the outlet tube sheet and passing through the plurality of first and second openings;
• a tube sheet overlay material located atop both the inlet tube sheet and the outlet tube sheet, wherein the tube sheet overlay material contains a plurality of third openings configured to allow the plurality of elongated tubes to pass there through, each third opening of the plurality of third openings comprises a beveled upper portion having a welding groove having a total area of from about 1.125 mm2 to about 10.125 mm2 located between a beveled sidewall of the beveled upper portion of the third opening and an outermost sidewall of the elongated tube passing through the third opening;
• and
• a welding material located inside the welding groove and affixed to the outermost sidewall of the elongated tube passing through the third opening, wherein the beveled upper portion of the third opening of the tube sheet overlay material has a J-bevel shape, a groove angle from about 0° to about 60°, and a bevel angle from about 0° to about 30°.

An ethylene oxide (EO) reactor comprising:

• an inlet tube sheet having a plurality of first openings and located at an inlet end of the EO reactor;
• an outlet tube sheet having a plurality of second openings and located at an outlet end of the EO reactor;
• a plurality of elongated tubes located between the inlet tube sheet and the outlet tube sheet and passing through the plurality of first and second openings;
• a tube sheet overlay material located atop both the inlet tube sheet and the outlet tube sheet, wherein the tube sheet overlay material contains a plurality of third openings configured to allow the plurality of elongated tubes to pass there through, each third opening of the plurality of third openings comprises a beveled upper portion having a welding groove located between a beveled sidewall of the beveled upper portion of the third opening and an outermost sidewall of the elongated tube passing through the third opening;
• a welding material located inside the welding groove and affixed to the outermost sidewall of the elongated tube passing through the third opening, wherein the welding material located inside the welding groove has a tensile strength of greater than 600 MPa;
• and
• an inlet line for introducing a feed gas comprising 1% to 40% ethylene and 3% to 12% oxygen into the EO reactor, wherein the EO reactor is configured to operate at a gas hourly space velocity of 1500 to 10,000 h−1, a reactor inlet pressure of 1 MPa to 3 MPa, a coolant temperature of 180° C. to 315° C., an oxygen conversion level of 10-60%, and an EO production rate (work rate) of 100-350 kg EO/m3 catalyst/hr and a change in ethylene oxide concentration, ΔEO, of from about 1.5% to about 4.5%, and wherein each elongated tube is filled with a silver-based epoxidation catalyst comprising an alumina support, a catalytically effective amount of silver or a silver-containing compound, and a promoting amount of one or more promoters.