Tube bundle heat exchanger of constant temperature gradient for thermophoretic deposition of aerosol particles

A tube bundle heat exchanger for thermophoretic deposition of aerosol particles, comprising:

• a housing, said housing comprising a chamber, a gas intake hole and an exhaust hole, said gas intake hole and said exhaust hole respectively extending from said chamber to the outside of said housing;
• a plurality of hot tube rows mounted in said chamber of said housing, each said hot tube row comprising a plurality of hot tubes respectively spaced from one another by at least one respective predetermined gap, said hot tubes being connected in series to define a hot fluid passage therein;
• and
• a plurality of cold tube rows mounted in said chamber of said housing, each said cold tube row comprising a plurality of cold tubes respectively spaced from one another by at least one respective predetermined gap, said cold tubes being connected in series to define a cold fluid passage therein;
• wherein said hot tube rows and said cold tube rows are alternately arranged in said chamber, and predetermined gaps are formed between the hot tube rows and the adjacent cold tube rows.