WO2018170615A1

WO2018170615A1 - Low-temperature distilled water purification technology and apparatus

Info

Publication number: WO2018170615A1
Application number: PCT/CN2017/000644
Authority: WO
Inventors: 申双君
Original assignee: 申双君
Priority date: 2016-12-20
Filing date: 2017-10-26
Publication date: 2018-09-27
Also published as: CN106915788A

Abstract

A method and apparatus for obtaining purified water by means of low-temperature distillation. The method comprises distilling water at a low temperature by using a reduced pressure distillation device to obtain purified water in the form of distilled water, and recovering heat energy released when steam is liquefied, so that energy is circularly utilized. The reduced pressure distillation device comprises a pressure reducing container (102), a condensation container (101), and a porous negative pressure tank (103) used for collecting distilled water. Under the control of a controller, raw water is constantly converted into distilled water. The present invention has a large water purification treatment amount and a thorough purification effect. The present invention can purify fresh water, treat saline water, satisfy household water purification requirements, and satisfy industrial massive production of purified water.

Description

[Correct according to Rule 26 18.12.2017] Low-temperature distilled water purification technology and device

The invention relates to the field of water treatment technology.

Background technique

Background technology on purified water: As human activities and industrialization become more and more high, water pollution is becoming more and more serious. Tap water, surface water and even a lot of groundwater are hard to meet people's demand for high quality water. The people are eager to get better and safer drinking water and high quality water. In this context, a water revolution broke out.

The development of canned water, the emergence of various water purifiers is the product of this era. Although the canned water meets the needs of some drinking water, its shortcomings are obvious.

The appearance of water purification equipment has changed the water supply to a certain extent. However, the water purifier generally adopts the filtration method. No matter which filtration method is used, the filter core and the filter material need to be replaced regularly, which also causes considerable trouble. Rubbish. Especially in areas lacking fresh water resources, it is even more difficult to use safe and sufficient clean water.

Summary of the invention:

In order to address the shortcomings and deficiencies of the prior art, it is a primary object of the present invention to provide a method for water purification, cryogenic distillation.

Another object of the present invention is to provide a specific apparatus for water purification by the above method.

1. The setting of the decompression container: The decompression container provided according to the low-temperature distillation technology is divided into two chambers of the evaporation chamber and the steam chamber for the purpose of distillation, and the container having the sealing performance can be divided into upper and lower chambers when divided into two chambers. It can also be divided into left and right chambers. The structure of the two types of decompression vessels with different methods is different. The installation position of the condensation tube (which can also be a condensed straight plate or a condensing curved plate, which is referred to as a condensing pipe for the sake of simplicity) is also different. , Class [1]: The container with sealing performance is partitioned into two chambers by left and right, one chamber is used as a vapor chamber, and the evaporation chamber is completely separated from the lower portion of the steam chamber, so that the water in the evaporation chamber cannot flow. In the steam chamber, the upper portion is connected to allow steam to be transferred from the evaporation chamber to the steam chamber, the condensation tube is installed below the steam chamber, and the condensed water is directly discharged from the bottom of the condensation tube. Class [2]: The container with sealing performance is divided into upper and lower chambers by a partition plate, the lower chamber is an evaporation chamber, and the upper chamber is a steam chamber. The partition plate is not completely separated from the upper and lower chambers, leaving a path for The steam generated in the lower evaporation chamber can smoothly reach the upper steam chamber. The condenser is placed above the steam chamber, and the distilled water produced by the condensation is collected by the separator. The separator is slightly inclined, and the distilled water can be collected along the separator to a place favorable for export. The two decompression containers work in exactly the same way, but because the condensing tubes are installed at different positions, the condensing container of the [2] type decompression container is easy to set up, the condensing tube replacement and cleaning are relatively convenient, and there is a distillation device as will be mentioned below. The exhaust is also better set.

2. A single decompression container can not fully meet the requirements of water purification, such as high heat recovery rate and high distillation speed. Therefore, a combined decompression vessel group distillation unit, a decompression vessel cluster box, is required. Cluster box consisting of type [1] decompression containers and by [2] The main difference between the cluster boxes consisting of decompression vessels is that the location of the condenser tubes is different. The cluster box consisting of the type [2] decompression vessels is also superior to the cluster box consisting of the type [1] decompression vessels. Explain the cluster box consisting of the [2] type decompression container and analyze where it is better. As shown in Fig. 1, a single-row decompression container cluster box integrated by four [2] type decompression containers, the cluster box includes a condensing container group 101 and a decompression container group 102, and a decompression container Group 102 has a total of 4 small rooms, one small room is a decompression container, and one decompression container is completely separated from the other decompression container except the bottom (corresponding to the drainage hole), each decompression container Divided into steam chambers and evaporation chambers that are not completely separated. Because the bottom is water-cooled, the decompression container should be drained from the bottom of the evaporation chamber when it is drained. To make evaporation occur on the surface, the influent water should come in from the upper part of the evaporation chamber. It is required that the evaporation chamber be further divided into two sizes. Since the pressure in the upper decompression vessel is larger than the pressure in the next decompression vessel, the bottom of the evaporation chamber is connected to the bottom of the evaporation chamber of the upper decompression vessel. The liquid level in the evaporation chamber of the pressure vessel is higher than the liquid level in the evaporation chamber, and the water in the small chamber overflows through the partition plate. This solves the problem that the decompression container should be drained from the lower part of the upper inlet water. The porous negative pressure tank of the decompression container can be built in Reduced pressure in the container, a hole directly into the distilled water collected in the separator of the porous negative pressure in the tank, as shown in FIG 1: a porous negative pressure tank 103 incorporated in the container 102. The cluster box integrated by the [2] type decompression vessel has a built-in porous negative pressure tank, and since the condensation tube is installed above the steam chamber, the condensation container can be integrated with the decompression container, and the integration is higher, and the connection is more. Simple, the condensing tube is replaced and cleaned more conveniently. The condensing tube can be cleaned during the distillation process. The cleaning operation has little effect. The cluster box consisting of the type [1] decompression container is inconvenient to have a built-in porous negative pressure tank, the condensing container and The decompression container is also not easy to be integrated, so the decompression container cluster box integrated by the [2] type decompression container is better, and the decompression container referred to below is the decompression type [2] unless otherwise specified. The container, referred to as the decompression container cluster box, is a cluster box integrated with the [2] type decompression container.

3. If necessary, the decompression container cluster box and the cluster box can be connected in parallel or in series. The volume of the decompression container in the cluster box can be designed according to requirements. The larger the volume of the single decompression container, the larger the condensation area of the condensation tube connected by the single decompression container, and the faster the distillation and purification of the single decompression container.

The principle of vacuum distillation and the distillation process: vacuum distillation is to introduce the raw water to a certain temperature and then introduce it into the evaporation chamber of the first-stage decompression vessel, because the pressure in the decompression vessel is controlled to be lower than the heated raw water. Under the condition of the saturated gas pressure corresponding to the temperature, the raw material water becomes a flashover of the superheated water portion. This flash evaporation has a tendency to increase the pressure inside the pressure reducing vessel, because the condenser tube and the pressure reducing vessel are at the same negative pressure. In the system, the liquefaction of steam in the condensing pipe has a tendency to decrease the pressure, and the two trends will eventually reach the dynamic equilibrium. This dynamic equilibrium of the vacuum distillation is the main difference from the multi-stage flashing technology. After partial flashing, the temperature is lowered, and the second-stage decompression container with lower pressure can be flashed again without restriction current. After multi-stage vacuum distillation, cold water is discharged from the last stage, and the exported cold water is used as The condensed water is placed in the condensation cycle, and the heat energy released by the liquefaction of the steam is recovered step by step. Vacuum distillation system consisting of a decompression vessel cluster box The distillation process is as follows: the raw water is introduced into the evaporation chamber of the first-stage decompression vessel from the inlet hole (hereinafter referred to as the first evaporation chamber, and the evaporation chamber of the second-stage decompression vessel is called the second evaporation chamber, and the third-stage decompression container The evaporation chamber is called the third evaporation chamber......), because the pressure inside the decompression vessel is lower than the saturation pressure of the steam at the temperature value of the hot water, the hot water evaporates in the first evaporation chamber to make the evaporation chamber and the steam chamber pressure There is a tendency to increase, the generated steam is sent to the condensing pipe, and the steam is liquefied by the condensed water in the condensing pipe, and the pressure in the condensing pipe and the steam chamber connected to the condensing pipe tends to decrease, and the two trends eventually Will reach dynamic balance. When the hot water is continuously introduced, the small chamber of the second evaporation chamber and the first evaporation chamber are connected to each other due to the bottom portion, and the water level of the second evaporation chamber is synchronously increased, and finally overflows to the second evaporation chamber. After the evaporation chamber reaches the design water level, the third evaporation chamber is overflowed to the third evaporation chamber, and so on. Each of the decompression containers flashes and condenses in the same dynamic balance as the first decompression container. The hot water comes in from the first decompression container, flows autonomously downward, and becomes decompressed from the last stage after becoming cold water. After the container is exported, the exported water is lifted by the water pump and sent to the upper level or the upper level of the last stage to participate in the condensation cycle as condensed water. The water pressure of the condensate in this stage is higher than the previous levels, and the condensed water Flowing forward to the first stage, when the condensed water flows out from the first stage condenser, most of the heat energy from the first stage to the penultimate stage is recovered, but the temperature is lower than the initial temperature, and after supplementing a small amount of heat energy In order to participate in the cycle again, a part of the raw water used for the final stage of refrigeration should be added to the purification cycle of the system to make up for the part of the water that is reduced by distillation.

If the raw water is seawater, the concentration of the brine will increase continuously as the distillation progresses. When the saturated solubility is exceeded, the salt will be removed and the salt will be deposited in the evaporation chamber. Influence, but it is almost impossible to clean out the salt. It is necessary to change the design. A sedimentary tube is placed under the evaporation chamber. Salt and other salts are deposited in the deposition tube. It is much easier to clean up. For example, use two deposition tubes at the same time, one work and one stop to clean.

Distilled water collection: The pressure of each decompression vessel in the decompression vessel cluster box is different, and the distillation of distilled water becomes a bit complicated. In addition, the negative pressure in each decompression vessel is maintained, and each decompression vessel is maintained. The internal negative pressure must be kept different, which is also complicated. The porous negative pressure tank shown in Fig. 2 solves the above two problems well. The distilled water outlet pipe is connected in turn to the inlet of the pressure regulating pipe of the porous negative pressure tank (the pressure vessel cluster box with the built-in porous negative pressure tank, and there is no need to connect the first-stage porous negative pressure tank). The pressure regulating tube of the porous negative pressure tank has the function of automatically adjusting the pressure. The pressure inside the condensing tube is stronger than that in the negative pressure tank. The distilled water in the pressure regulating tube is pressed out more, and the water level of the pressure regulating tube is low; the pressure inside the condensing tube is relatively negative. The pressure inside the pressure tank is small, the distilled water in the pressure regulating tube is small, the water level is high, the porous negative pressure tank can be set in multiple stages, and the water level in the primary negative pressure tank is controlled by the secondary porous negative pressure tank, above the negative pressure tank It is a vacuum because the water has a saturated air pressure, so the negative pressure in the negative pressure tank is actually controlled by the water temperature in the tank. The distilled water in the primary negative pressure tank is all the decompression containers connected to the negative pressure tank. After being discharged together, the temperature is close to the average value of the raw material water of each of the decompressing vessels connected thereto, and the secondary pressure tank of the second or more is formed by mixing distilled water discharged from a plurality of upper-stage negative pressure tanks, and the temperature is close to these. Primary negative pressure tank internal distillation The average value of the water and water temperature, and because the condensing tube and the decompression vessel are in the same negative pressure system, the negative pressure in the condensing tube is controlled, and the negative pressure in the decompression container is controlled. Because the length of the pressure regulating tube is limited, the pressure is emphasized. The scope is limited, and the connection cannot be exceeded. The lower level pressure tank is used to control the water level of the upper stage negative pressure tank, and the water level controller controls the water level of the last stage negative pressure tank.

Exhaust of the vacuum distillation system: Due to the presence of insoluble gases in the raw water, pre-urethane treatment is required. The distillation system needs to be vented after running for a period of time. When installing the decompression vessel cluster box, the exhaust gas should be taken into consideration.

The vacuum distillation carried out by a vacuum distillation system, no matter how high the water production ratio is, under the premise that the heat source can guarantee the supply, it will be practical to reach the water production amount of 1m ^{3 in} an hour or two, and the decompression The speed of distillation in the distillation system depends mainly on the speed of heat exchange. The following is a theoretical calculation of the speed of heat exchange. The speed of heat transfer from the inside to the outside of the condensing pipe through the wall of the condensing pipe is calculated by one hour. The coefficient is 200 (the cheap aluminum tube is about 200, and the thermal conductivity of copper is generally more than 300), the wall thickness is 0.1cm, and the temperature difference between the inside and outside of the condenser is calculated as 1 °C. The smaller the temperature difference is, the larger the water ratio is, the actual temperature difference. Of course, more than 1 ° C), a decompression container condensing tube has a diameter of 20 cm and a length of 40 cm. The cluster box integrated by 16 such decompression containers is about 90 cm long and 90 cm wide, and four such cluster boxes are connected in series to form a distillation system. First calculate the heat transfer speed of a single decompression vessel: the side wall area of the condenser tube is 0.2π×0.4m ² , the top surface area of the condenser tube is 0.1×0.1πm ² , and the heat conduction for 1 hour is: (0.2π×0.4+0.1×0.1π)×200 ×1×3600÷0.001≈2.03×10 ³ (Joules), that is, the theoretical calculation of the condenser tube of a vacuum vessel for 1 hour can transfer about 100 kg of water to the outside of the tube to evaporate the required heat, 64 decompression vessels 1 An hour can transfer about 6.4 tons of water to evaporate. Of course, there are actually many factors that affect heat transfer. For example, condensate will adhere to the wall of the condenser to affect heat transfer. The deposition of scale will cause the heat transfer of the condenser. The reduction, the impact of these factors is reduced in the manufacture of decompression container groups or installation, and will not be explained here.

Industrial adaptability and best practice: The water purification device of the invention can be adapted to large-scale, factory desalination, polluted water purification, and also suitable for individual household water and drinking water purification, therefore: 1. Production and promotion The vacuum distillation unit has a promising future; 2. The large-scale seawater desalination plant is constructed by using the technology of the present invention, and a large-scale desalination plant can be constructed, which can obtain not only fresh water but also by-products; 3. construction of canned pure water plants; 4. application to other Equipment that uses high quality fresh or distilled water, such as ships, warships and other industrial machinery and equipment, must be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a single-row decompression container cluster box assembled from four types of [2] type decompression containers, 101 is a group of condensation vessels, 102 is a group of decompression vessels, and 103 is a porous negative pressure. The tank, 104 is a condensing tube. In order to facilitate the replacement of the condensing tube, the connection between the condensing tube and the decompression container, and the connection between the condensing container and the decompression container are all connected by a sealing washer and a rod, and the pressure is reduced during actual production. The container can be multi-column, and the total number of single columns does not have to be integrated by four decompression containers as shown on the drawing, and can be more according to actual needs. 001 is the water inlet of the decompression container cluster box, that is, the water inlet of the first evaporation chamber, 002 is the water outlet, that is, the drain port of the last stage decompression container, 003 is the condensate outlet of the condensation container, and 004 is the inlet of the condensate water, minus The hot water in the pressure vessel flows from the 001 hole to the 002 hole, and the condensation container is just the opposite. The condensed water flows from the 004 hole to the 003 hole. Figure 2 is a schematic diagram of a porous negative pressure tank, 201 is a negative pressure tank body, 202 is a pressure regulating tube opening of a porous negative pressure tank, and 203 is a pressure regulating tube of a porous negative pressure tank (the pressure regulating tube of the porous negative pressure tank is originally called The method is a condensation extension tube, because the name is not enough, it is called a pressure regulating tube, which is hereby explained), the 204 outlet is an inlet and outlet of the porous negative pressure tank connected to the pressure regulating tube, and 205 is a porous negative pressure tank distilled water outlet hole. It is also the water level control hole in the tank. The number of pressure regulating tubes of the porous negative pressure tank is designed according to actual needs, and can be increased or decreased. It can be made into one tank and one row of tubes, or can be set as one tank and multiple tubes, and the pressure regulating tube. It does not have to be placed in the tank, and can be placed outside the tank as needed. Figure 2 shows two situations, one: the pressure regulating tube is placed in the negative pressure tank, and the other is: the pressure regulating tube is placed. Negative pressure cans outside the tank.

Except that the vent hole is drawn at the condensing pipe in Fig. 1, other vent holes are required, which are not shown in the figure, and the vent hole should be provided in actual production.

Claims

The low-temperature distilled water purification technology is a technique in which water is distilled at a low temperature by a vacuum distillation apparatus to obtain purified water in the form of distilled water, and heat energy discharged by liquefaction of water vapor is recovered, and energy is recycled, characterized in that the boiling point of the water is lowered as the pressure is lowered. The characteristic is that in the decompression container which can maintain the negative pressure constant by extracting or deriving the distilled water generated in the distillation process, the water heated by the solar energy, air energy or other heat source is subjected to multiple vacuum distillation at the same time. Condensation in the same decompression vessel, while obtaining distilled water, recovering the heat energy liquefied by the water vapor, and evaporation and liquefaction occur simultaneously in the same decompression vessel, and evaporation and liquefaction are in dynamic equilibrium.
The vacuum distillation apparatus is a cryogenic distillation apparatus which is based on a plurality of decompression vessel integrated decompression vessel cluster boxes and is connected with a control device by a known device, and thereby constitutes a distillation system, which is based on the present invention. In the invention, the special device for collecting distilled water, the porous negative pressure tank, the distillation principle of the device of the present invention is somewhat similar to that of the multi-stage flashing device, and the maintenance of the negative pressure is simpler than the multi-stage flashing device. The recovery of energy is greatly improved, and in particular, the maintenance energy consumption of the negative pressure is relatively small. The vacuum distillation of the present invention has almost no backflow of raw material water, so that high energy recovery can be ensured.
The decompression container provided according to all the above claims is a container having a sealing property which is divided into two chambers of an evaporation chamber and a vapor chamber for the purpose of distillation, the condensation tube is in communication with the vapor chamber, and the intermediate partition does not have an evaporation chamber, The steam chambers are completely separated, and the steam can easily enter the steam chamber from the evaporation chamber. When the evaporation chamber is divided into the upper and lower chambers of the lower steam chamber, the separator functions to collect distilled water and divide into two chambers. The function is to prevent the water in the evaporation chamber from flowing into the steam chamber. When the pressure reducing container is working, the raw water enters the evaporation chamber to evaporate, and the generated steam is condensed in the steam chamber. The heat transfer from the condensing tube to the condensed water is transferred to the condensed water to recover the energy. The negative pressure tank control outlet tube directly leads or controls the distilled water device to extract the distilled water generated in the distillation process to control the negative pressure in the decompression container, so that the decompression container maintains a constant negative pressure, thereby continuously providing a place for cryogenic distillation, one reduction The pressure vessel has at least one condensing tube or a condensing straight plate or a condensing curved plate connected to its steam chamber, and the condensing tube cavity or cold The inner surface of the plate and the decompression container are in the same negative pressure system, and the raw material water introduced into the decompression container is superheated due to low pressure in a low temperature state, and a part of water can easily change state of matter by water. It turns into water vapor, and the water vapor is continuously liquefied in the condensing pipe, and the released heat is recovered by the condensed water. When the decompression container is working, the evaporation and liquefaction in the container occur synchronously, and the evaporation and liquefaction are in dynamic equilibrium.
According to the preceding claim, a plurality of decompression containers are further assembled into a decompression container cluster box and a decompression container cluster based on a single decompression container that cannot fully meet the requirements of high water recovery rate, high distillation rate, and the like. The characteristics of the box are that the decompression containers in the cluster box are combined and distilled. During the continuous distillation, the heat energy of the condensed water recovery is gradually superimposed, and the decompression container cluster box has good integration, convenient control, high heat recovery rate and large water-making ratio. The distillation system consisting of a decompression vessel cluster box is simple to install and can meet the different needs of large and small clean water.
The porous negative pressure tank introduced according to all the above claims is an indispensable device for vacuum distillation, and the vacuum distillation has specific requirements for the collection of distilled water, and the negative pressure of each decompression container in the decompression container cluster box is not Similarly, the distilled water derived from each decompression vessel has a different negative pressure, and the derivation of distilled water is the basis for maintaining a constant negative pressure of each decompression vessel. When it is necessary to derive distilled water, how much to export, it is also necessary to control, porous negative pressure tank It is a special distilled water collecting device designed to solve the above two problems. The porous negative pressure tank is characterized in that the porous negative pressure tank can automatically adapt and cooperate with the distilled water outlet pipe or the distilled water device to control the negative pressure in the pressure reducing container, and the porous negative pressure. The introduction of the tank can greatly reduce the other controllers of the system, and the control is more precise.