Method for recycling formalin

• US 5,685,987 A
• Filed: 09/24/1996
• Issued: 11/11/1997
• Est. Priority Date: 09/24/1996
• Status: Expired due to Fees

• Current Assignee: Tresco, LLC, Vision Medical, Inc.
• Original Assignee: Tresco, LLC, Vision Medical, Inc.
• Inventors: Hixon, Leonard Lee Jr., Lafriniere, Michael Robert, Rees, John Joseph Matthews, Taylor, Joe Edward
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US08/718,866
• Time in Patent Office: 413 Days
• Field of Search: 134/10, 134/13, 134/111, 210/87, 210/90, 210/93, 210/137, 210/143, 210/167, 210/192, 210/195.2, 210/198.1, 210/257.2, 210/258, 210/259, 210/321.69, 210/424, 210/434, 210/636, 210/637 , 210/651, 210/652, 210/663, 210/669, 210/739, 210/743, 210/748, 210/760, 210/805, 210/806, 422/28, 422/36, 422/306, 422/1, 239/416.5, 239/417.3, 27/11
• US Class Current: 210/636
• CPC Class Codes: A61L 2/10 Ultraviolet radiation
• CPC Class Codes: A61L 2/202 Ozone
• CPC Class Codes: B01D 2321/168 Use of other chemical agents
• CPC Class Codes: B01D 2321/185 Aeration
• CPC Class Codes: B01D 61/02 Reverse osmosis; Hyperfiltration ; Nanofiltration
• CPC Class Codes: B01D 61/14 Ultrafiltration; Microfiltration
• CPC Class Codes: B01D 61/20 Accessories; Auxiliary operations
• CPC Class Codes: B01D 61/22 Controlling or regulating
• CPC Class Codes: B01D 65/00 Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
• CPC Class Codes: B01D 65/02 Membrane cleaning or sterilisation ; Membrane regeneration

Abstract

A formalin fluid recycler has a combination triple pipe nozzle for introducing dirty fluid into the recycler and for expelling concentrate and permeate fluid therefrom. Dirty fluid is pumped through a strainer, filtration module and charcoal filter to purify and clarify the dirty fluid. The formalin fluid can be recirculated in the system via the nozzle or be directed to a clean receptacle. Dirty formalin fluid is further cleansed by Ozone and ultraviolet light. Percent concentration and pH level of clean recycled formalin fluid is adjusted outside of the main recycling loop. Cleaning and preservative solutions are circulated through the recycler when necessary.

Claims

1. A method of recycling a fluid consisting essentially of formalin, comprising the steps of:

pumping a particle-containing formalin fluid from a dirty tank through a first strainer or pre-filter thereby removing large particles;

filtering the fluid through a filtration module to remove finer particles not strained by said strainer or pre-filter;

and routing permeate resulting from said filtering step to one of the dirty tank, a clean tank and a charcoal filter.

2. The method of claim 1, further comprising charcoal-filtering the permeate resulting from said filtering step.

3. The method of claim 1, further comprising inserting spongeballs prior to said filtering step and retrieving said spongeballs after said filtering step.

4. The method of claim 1, further comprising controlling a flow of concentrate flowing out of the filtration module.

5. The method of claim 1, further comprising gauging the flow of permeate resulting from said filtering step.

6. The method of claim 1, further comprising controlling at least one of the pH and percent formalin of said permeate.

7. The method of claim 1, further comprising purifying the formalin with ozone.

8. The method of claim 1, further comprising purifying the formalin with ultraviolet light.

9. The method of claim 1, further comprising purifying fumes with one of ozone and charcoal.

10. The method of claim 1, wherein the filtering step is performed at room temperature.

11. The method of claim 1, wherein the fluid is maintained at a temperature below its vapor or distillation temperature.