Background
At present, along with increasing attention to environmental pollution in China, the application of a forward osmosis liquid drawing technology is mostly still in a laboratory research stage in zero discharge treatment of high-concentration wastewater, and a certain distance is left from real industrial application. The lack of high performance forward osmosis membranes and high osmotic pressures and the ease of recycling of draw solutions is a major obstacle limiting their industrial application. At present, in order to realize zero-discharge sewage treatment, the research on the forward osmosis liquid flow direction distribution technology in China is started later, and a large gap still exists in the technical problem.
The conventional forward osmosis draw solution flow distribution technology has the characteristics of insufficient product design, easy pollution and blockage in the inflow process of high-concentration water and the like, and the following problems are that the forward osmosis draw solution flow distribution application is as follows:
1. a compact contaminated layer is likely to occur when high-concentration water is treated.
2. When the raw water concentration is constant, the concentration of the draw solution is likely to increase, and the osmotic pressure difference is unstable.
3. The absorption liquid osmotic pressure flux and the membrane problems are easily influenced after the recovery times are more.
Disclosure of Invention
The invention provides a forward osmosis draw solution flow direction distribution device, which is provided with an FO membrane element, wherein high-concentration forward osmosis draw solution enters from the left end of the FO membrane element and is treated by the FO membrane element, and then low-concentration draw solution is output from the right end of the FO membrane element;
the FO membrane component comprises a central tube component and a FO membrane sleeved on the outer wall of the central tube component, wherein the central tube component comprises a left central tube component and a right central tube component, and the left central tube component and the right central tube component are connected through Y-shaped shunt tubes;
the left central tube assembly and the right central tube assembly are both provided with inner tubes and outer tubes which are arranged in concentric circles, water collecting holes are formed in the outer tubes, the inner tubes of the left central tube assembly are connected with the outer tubes of the right central tube assembly through Y-shaped shunt tubes, and the right ends of the inner tubes of the right central tube assembly are connected with FO membranes on the right side through pipelines.
Furthermore, the FO membrane component is installed in the shell, end covers are arranged at two ends of the shell, a central fixing hole is formed in each end cover, and the left end and the right end of the central tube component are fixed in the central fixing hole.
A forward osmosis draw method for using the forward osmosis draw solution to a distribution device comprises the following processes:
the high concentration forward permeate draw enters the left central tube section of the FO membrane element with a portion of the high concentration forward permeate draw entering the inner tube of the left central tube section and another portion entering the outer tube of the left central tube section;
the high-concentration forward osmosis absorption liquid of the outer pipe of the left central pipe assembly is transferred into the FO membrane through the water collecting hole to be absorbed;
the high-concentration forward osmosis absorption liquid of the inner pipe of the left central pipe assembly is conveyed to the outer pipe of the right central pipe assembly through the Y-shaped shunt pipe and is transferred to the FO membrane again through the water collecting hole of the outer pipe of the right central pipe assembly for absorption;
and the low-concentration drawing liquid generated after repeated drawing is output from the inner pipe of the right central pipe assembly.
The invention has the advantages that:
(1) draw liquid reposition of redundant personnel, technical advantage, simple and convenient low energy consumption is difficult for the scale deposit.
(2) The compactness is high, can possess high osmotic pressure difference, has better solubility to water.
(3) The absorption liquid is stable to recover and has low pollution.
Detailed Description
In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.
In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.
The forward osmosis draw solution is suitable for inorganic compound draw solutions, the draw solutions can be recycled, but the osmotic pressure of the draw solutions and the flux of membranes are generally affected with the increase of the recycling times, so that the forward osmosis draw solutions have the problems of high cost, limited use times and the like.
In forward osmosis, the draw solution is important as the membrane, and the driving force of the forward osmosis membrane process is the osmotic pressure difference between the draw solution and the wastewater. Therefore, selection and constitution of the drawing liquid are also one of important techniques. The invention provides a forward osmosis draw solution flow direction distribution device, which is provided with an FO membrane element, wherein high-concentration forward osmosis draw solution enters from the left end of the FO membrane element and is treated by the FO membrane element, and then low-concentration draw solution is output from the right end of the FO membrane element;
the FO membrane element comprises a center tube assembly and a FO membrane 30 sleeved on the outer wall of the center tube assembly, wherein the center tube assembly comprises a left center tube assembly 10 and a right center tube assembly 20, and the left center tube assembly 10 and the right center tube assembly 20 are connected through Y-shaped shunt tubes 50;
left center tube assembly 10 and right center tube assembly 20 all are equipped with inner tube and the outer tube that the concentric circles set up, are equipped with the water collecting hole on the outer tube, and left center tube assembly 10's inner tube passes through Y type shunt tubes 50 and links to each other with right center tube assembly 20's outer tube, and right center tube assembly 20's inner tube right-hand member passes through the pipeline with the FO membrane 30 on right side and links to each other.
In addition, a housing is included, the FO membrane 30 components are mounted in this housing 40, end caps 41 are provided at both ends of the housing, the end caps 41 are provided with a center fixing hole, and the left and right ends of the center pipe assembly are fixed in this center fixing hole
Meanwhile, the invention also provides a forward osmosis drawing method process for adopting the forward osmosis drawing liquid flow to the distribution device, which comprises the following steps:
the high concentration forward osmosis draw solution enters the left center tube assembly 10 of the FO membrane 30 element, with a portion of the high concentration forward osmosis draw solution entering the inner tube 11 of the left center tube assembly 10 and another portion entering the outer tube 12 of the left center tube assembly 10;
the high concentration forward osmosis draw solution in the outer tube 12 of the left center tube assembly 10 is spontaneously transferred into the FO membrane 30 through the water collection holes 12a for drawing (high osmotic pressure side);
the high concentration forward osmosis draw solution from the inner tube 10 of the left base pipe assembly 10 is transported through the Y-manifold 50 into the outer tube 22 of the right base pipe assembly 20 and is again transferred through the water collection holes in the outer tube of the right base pipe assembly 20 into the FO membrane 30 for draw (low osmotic pressure side);
the low-concentration draw solution generated after repeated drawing in the FO membrane 30 is output from the inner pipe 21 of the right base pipe assembly 20.
By adopting the scheme of the invention, sufficient osmotic pressure difference exists between the drawing liquid and the wastewater, so that clean water can continuously permeate out, and the structure and the performance of the membrane and the quality of the pure water cannot be influenced; in addition, it should be possible to separate pure water therefrom by relatively simple methods to obtain fresh water.
The invention has the advantages that:
(1) the technical advantage of drawing liquid splitting.
(2) Simple, convenient, low in energy consumption and not easy to scale.
(3) The compactness is high, can possess high osmotic pressure difference, has better solubility to water.
(4) The absorption liquid is stable to recover and has low pollution.
The above description is of the preferred embodiment of the invention. It is to be understood that the invention is not limited to the particular embodiments described above, in that devices and structures not described in detail are understood to be implemented in a manner common in the art; those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or modify equivalent embodiments to equivalent variations, without departing from the spirit of the invention, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.