Distillation system for treating waste organic solvent

• US 5,217,579 A
• Filed: 06/28/1991
• Issued: 06/08/1993
• Est. Priority Date: 02/21/1991
• Status: Expired due to Fees

• Current Assignee: Toyota Kagaku Kogyo Kabushiki Kaisha
• Original Assignee: Toyota Kagaku Kogyo Kabushiki Kaisha
• Inventors: Fujii, Tadao, Kusakabe, Fumiyuki, Morishita, Fumio, Ohta, Shiro
• Primary Examiner(s): Manoharan, Virginia
• Application Number:
  US07/722,954
• Time in Patent Office: 711 Days
• Field of Search: 202/154, 202/155, 202/237, 202/236, 202/185.1, 202/175, 202/205, 202/269, 202/265, 159/48.1, 159/DIG. 16, 159/6.2, 159/2.2, 159/25.2, 159/DIG. 23, 159/49, 159/DIG. 10, 203/78, 203/89, 203/90, 203/DIG. 9, 203/72, 366/323, 366/322, 425/203
• US Class Current: 202/154
• CPC Class Codes: B01D 1/225 with blades or scrapers
• CPC Class Codes: B01D 3/146 Multiple effect distillation
• CPC Class Codes: C02F 1/048 Purification of waste water by evaporation
• CPC Class Codes: Y10S 159/10 Organic
• CPC Class Codes: Y10S 159/23 Cooling
• CPC Class Codes: Y10S 203/09 Plural feed

Abstract

A system for continuously recovering renewable volatile compounds by boiling points from waste organic solvent with minimum energy loss, and an improved thin membrane distillation apparatus for efficient distillation of renewable volatile compounds from waste organic solvent and enforced discharge of the residue or sludge. The waste treatment system includes a thin membrane distillation apparatus, a cooling unit, a first distillation unit, and a second distillation unit connected in this sequence. Alternatively, the system includes two thin membrane distillation apparatus, a reduced pressure distillation unit, and a normal pressure distillation unit connected in this sequence. The thin membrane distillation apparatus includes a decompression chamber, a waste inlet, an outlet for volatile compound, an air-tight chamber, and a breaking mechanism with a screw head movable into the air-tight chamber.

Claims

1. In a system for treating liquid waste containing organic solvent to recover volatile compounds from said waste, said system having at least one distillation element for distilling a mixture of volatile compounds from said waste, the improvement wherein

A. said at least one distillation element comprises

(i) a decompression chamber having an upper end and a lower end and tubular walls at which compounds vaporize,

(ii) an inlet for receiving said waste and an outlet for releasing said vaporized compound, and

(iii) a rotating member within said decompression chamber having radially extending blades for spraying onto the interior of said tubular walls said waste received at said inlet,

B. said system further comprises

(i) a reduced pressure fractional distillation means coupled to said at least one distillation element for removing impurities from said distilled volatile mixture,

(ii) a normal pressure fractional distillation means coupled to said reduced pressure fractional distillation means for separately distilling from a purified volatile mixture volatile compounds of lower boiling points and volatile compounds of higher boiling points,

(iii) an airtight chamber connected to the lower end of said decompression chamber via a first valve, and

(iv) a breaking mechanism having a breaking head movable from a position outside said airtight chamber to a position within said airtight chamber.

2. In a system according to claim 1, the improvement wherein said reduced pressure fractional distillation means further includes means forming another decompression chamber arranged for directly receiving said distilled volatile mixture from said at least one distillation element.

3. In a system according to claim 1, the improvement wherein at least one of said reduced pressure fractional distillation means and said normal pressure fractional distillation means includes means for refluxing a portion of said purified volatile mixture by

removing said portion of said purified volatile mixture from said at least one fractional distillation means,

passing said removed portion of said purified volatile mixture from said at least one fractional distillation means through a cooling means, and returning said removed portion of said purified volatile mixture from said at least one fractional distillation means to said at least one fractional distillation means for further purification and distillation.

4. In a system according to claim 17, wherein said breaking mechanism further comprises

means forming a cylinder having a central rod which alternately moves into said airtight chamber and out of said airtight chamber, and

said breaking head comprises a screw head located on top of said rod having criss-crossing blades.