Industrial Evaporation Apparatus

Abstract

It is an object of the present invention, in the case of an apparatus in which a liquid containing material having a lower boiling point than that of the liquid is made to flow down along an external surface of a guide, during which time the lower boiling point material is evaporated, to provide a specific apparatus that can be operated stably for a prolonged period of time on an industrial scale such that not less than 1 ton/hr of the liquid is subjected to the evaporation, and furthermore to provide a specific industrial evaporation apparatus in which there are no problems due to degeneration caused by some of the liquid residing in the apparatus for a prolonged period of time. The present inventors have reached to the present invention upon discovering that the above object can be attained, and a high-quality and high-purity concentrated liquid or condensation polymer or thermoplastic polymer can easily be obtained, by using an industrial evaporation apparatus having a specified structure in which there are guides that do not themselves have a heat source, a flow path controlling member having a function of making the liquid fed onto a perforated plate from a liquid receiving port flow mainly from a peripheral portion toward a middle portion of the perforated plate is provided in a liquid feeding zone, the ratio of the volume V (m 3 ) of the space in which the liquid can be present in the liquid feeding zone from the bottom of the liquid receiving port (i.e. the joint between the liquid receiving port and a top internal wall of the liquid feeding zone) to an upper surface of the perforated plate, and the upper surface area T (m 2 ) of the perforated plate including the upper surface area of the holes therein, i.e. the value of V/T, is in a specified range (formula (6)), and formulae (1) to (5), or formulae (1) to (12), or formulae (1) to (14), are satisfied.

1 . An industrial evaporation apparatus in which a liquid containing a material having a lower boiling point than that of said liquid is made to flow down along an external surface of a guide that does not themselves have a heat source, during which time said lower boiling point material is evaporated, wherein the improvement comprises: 
 (1) said evaporation apparatus comprising a liquid receiving port; a liquid feeding zone for feeding said liquid via a perforated plate to said guide provide in an evaporation zone; said evaporation zone having a plurality of guides that extend downward within a space enclosed by said perforated plate, a side-wall casing, and a bottom-wall casing; an evaporated material outlet provided in said evaporation zone; and a liquid discharge port provided in a lowermost portion of the bottom-wall casing;    (2) a flow path controlling member which has a function of making said liquid fed onto the perforated plate from said liquid receiving port flow mainly from a peripheral portion toward a middle portion of the perforated plate being provided in said liquid feeding zone;    (3) an internal sectional area A (m 2 ) taken through a horizontal plane of the side-wall casing of said evaporation zone satisfying the following formula (1):      0.7≦A≦300  (1);    (4) a ratio between said A (m 2 ) and an internal sectional area B (m 2 ) taken through a horizontal plane of the liquid discharge port satisfying the following formula (2):      20 ≦A/B≦ 1000  (2);    (5) the bottom-wall casing constituting the bottom portion of said evaporation zone being connected at an internal angle C (°) to said side-wall casing on said bottom-wall casing, wherein said angle C (°) satisfies the following formula (3):      110≦C≦165  (3);    (6) a length h (cm) of each of said guides satisfying the following formula (4):      150≦h≦5000  (4);    (7) a total external surface area S (m 2 ) of said guides satisfying the following formula (5):      2≦S≦50000  (5);    (8) volume V (m 3 ) of a space in which said liquid is able to be present in said liquid feeding zone from said liquid receiving port to an upper surface of the perforated plate, and an upper surface area T (m 2 ) of the perforated plate including the upper surface area of holes therein satisfying the following formula (6):      0.02(m)≦ V/T≦ 0.5(m)  (6); and    (9) said volume V (m 3 ), and the volume Y (m 3 ) of a space in the evaporation zone satisfying the following formula (7):      10 ≦Y/V≦ 500  (7).    
   
   
       2 . The industrial evaporation apparatus according to  claim 1 , wherein not less than 1 ton/hr of said liquid is subjected to the evaporation.  
   
   
       3 . The industrial evaporation apparatus according to  claim 1  or  2 , wherein an angle E (°) between an internal sidewall surface of said liquid feeding zone and said perforated plate satisfies the following formula (8):  
       100≦E<180  (8).  
   
   
       4 . The industrial evaporation apparatus according to  claim 1 , wherein said side-wall casing of said evaporation zone is cylindrical with an inside diameter D (cm) and a length L (cm), the bottom-wall casing connected at a bottom portion of said side-wall casing is conical and the liquid discharge port, which is in the lowermost portion of the conical bottom-wall casing, is cylindrical with an inside diameter d (cm), wherein D, L and d satisfy the following formulae (9), (10), (11) and (12):  
       100≦D≦1800  (9)  5 ≦D/d≦ 50  (10)  0.5 ≦L/D≦ 30  (11)    h− 20 ≦L≦h+ 300  (12).  
   
   
       5 . The industrial evaporation apparatus according to  claim 1 , wherein the h satisfies the following formula (13):  
       400<h≦2500  (13).  
   
   
       6 . The industrial evaporation apparatus according to  claim 1 , wherein one of said guides is cylindrical, or pipe-shaped and made to be such that the liquid and/or gaseous material cannot enter therein, with an outside diameter r (cm), wherein r satisfies the following formula (14):  
       0.1≦r≦1  (14).  
   
   
       7 . The industrial evaporation apparatus according to  claim 1 , wherein said guides comprise guides according to  claim 6 , and the guides are joined together by transverse supports.  
   
   
       8 . The industrial evaporation apparatus according to  claim 1 , wherein said guides comprise guides according to  claim 6 , and form one of a grid-like or mesh-like guide structure in which the guides are fixed together by transverse supports, a three-dimensional guide structure in which a plurality of grid-like or mesh-like guide structures are arranged in front of and behind one another and are fixed together by transverse supports, and a jungle-gym-like three-dimensional guide structure in which the guides are fixed together in front of and behind, and left and right of, one another by transverse supports.  
   
   
       9 . The industrial evaporation apparatus according to  claim 1 , wherein said liquid is a melt of a monomer or a mixture of two or more kinds of monomers for producing a condensation polymer, and/or a prepolymer of the condensation polymer, and/or the condensation polymer, the lower boiling point material is a by-produced material and/or oligomer produced through condensation polymerization, and said industrial evaporation apparatus is a condensation polymer polymerization apparatus for removing said lower boiling point material from said melt by evaporation so as to increase a polymerization degree of the prepolymer of the condensation polymer and/or the condensation polymer.  
   
   
       10 . The industrial evaporation apparatus according to  claim 9 , wherein the condensation polymer is a polyester, a polyamide, or a polycarbonate.  
   
   
       11 . The industrial evaporation apparatus according to  claim 1 , wherein said liquid is a melt of a thermoplastic polymer A, said lower boiling point material is a monomer, an oligomer, and a by-produced material contained in the polymer, and the industrial evaporation apparatus is a purifying apparatus for removing said lower boiling point material from said melt by evaporation so as to increase purity of said thermoplastic polymer A.  
   
   
       12 . The industrial evaporation apparatus according to  claim 11 , wherein said thermoplastic polymer A is a polystyrene-based polymer, a polyvinyl chloride-based polymer, a polyvinylidene chloride-based polymer, a polyacrylonitrile-based polymer, a polyacrylic ester-based polymer, a polymethacrylic ester-based polymer, or a thermoplastic elastomer.  
   
   
       13 . The industrial evaporation apparatus according to  claim 1 , wherein said liquid is a solution of a thermoplastic polymer B, said lower boiling point material is a solvent in which said thermoplastic polymer is dissolved and/or a monomer, an oligomer, and a by-produced material contained in said polymer solution, and said industrial evaporation apparatus is a separation recovery/purification apparatus for removing said low boiling point material from said solution by evaporation so as to separate and thus recover said thermoplastic polymer from said solution and increase purity of said thermoplastic polymer.